The Project Gutenberg eBook of Field's Chromatography, by George Field

This eBook is for the use of anyone anywhere in the United States and
most other parts of the world at no cost and with almost no restrictions
whatsoever. You may copy it, give it away or re-use it under the terms
of the Project Gutenberg License included with this eBook or online at
www.gutenberg.org. If you are not located in the United States, you
will have to check the laws of the country where you are located before
using this eBook.

Title: Field's Chromatography
       or Treatise on Colours and Pigments as Used by Artists

Author: George Field

Editor: Thomas Salter

Release Date: March 27, 2007 [EBook #20915]
[Most recently updated: November 19, 2022]

Language: English

Produced by: Barbara Tozier, Bill Tozier, Jacqueline Jeremy
and the Online Distributed Proofreading Team at
http://www.pgdp.net

*** START OF THE PROJECT GUTENBERG EBOOK FIELD'S CHROMATOGRAPHY ***




_SALTER'S EDITION._

FIELD'S CHROMATOGRAPHY;

OR,

TREATISE ON COLOURS AND PIGMENTS

AS USED BY ARTISTS.

_AN ENTIRELY NEW AND PRACTICAL EDITION_;

REVISED, REWRITTEN, AND BROUGHT DOWN TO THE PRESENT TIME.

BY

THOMAS W. SALTER, F.C.S.


Ars probat artificem.

LONDON:

WINSOR AND NEWTON, 38, RATHBONE PLACE,

Manufacturing Artists' Colourmen by Special Appointment
to Her Majesty, and Their Royal Highnesses the Prince and
Princess of Wales.

[The Right of Translation is reserved.]




CONTENTS.


PART I.
ON COLOURS AND COLOURING.

Chapter.                                                        Page.

    I.--On Colouring                                               3

   II.--On the Relations and Harmonies of Colours                 13


PART II.
ON COLOURS AND PIGMENTS GENERALLY.

  III.--On Classes of Colours                                     27

   IV.--On the Durability and Fugacity of Pigments                31

    V.--On the General Qualities of Pigments                      46


PART III.
ON COLOURS AND PIGMENTS INDIVIDUALLY.

   VI.--On Colours and Pigments individually                      57

  VII.--On the Neutral, White                                     62

 VIII.--On the Primary, Yellow                                    81

   IX.--On the Primary, Red                                      127

    X.--On the Primary, Blue                                     183

   XI.--On the Secondary, Orange                                 239

  XII.--On the Secondary, Green                                  263

 XIII.--On the Secondary, Purple                                 294

  XIV.--On the Tertiary, Citrine                                 310

   XV.--On the Tertiary, Russet                                  320

  XVI.--On the Tertiary, Olive                                   325

 XVII.--On the Semi-Neutral, Brown                               334

XVIII.--On the Semi-Neutral, Marrone                             362

  XIX.--On the Semi-Neutral, Gray                                372

   XX.--On the Neutral, Grey                                     381

  XXI.--On the Neutral, Black                                    387

        Addendum                                                 414

        Index                                                    417




NOTICE.


Among the works consulted in this Edition are the following, from most
of which extracts have been taken:

    Bancroft's Philosophy of Colours.

    Brande's Manual of Chemistry.

    Chemical News.

    Chevreul on Colour.

    Fownes' Manual of Chemistry.

    Gmelin's Handbook of Chemistry.

    Handbooks on Art.

    Liebig and Kopp's Annual Report of the Progress of Chemistry.

    Mérimée's Painting in Oil.

    Muspratt's Dictionary of Chemistry.

    Normandy's Commercial Handbook of Chemical Analysis.

    O'Neill's Chemistry of Calico Printing.

    Quarterly Journal of the Chemical Society.

    Ruskin's Elements of Drawing.

    Watts' Dictionary of Chemistry.




PART I.

       *       *       *       *       *

ON COLOURS AND COLOURING.




CHROMATOGRAPHY;

OR,

A TREATISE ON COLOURS AND PIGMENTS.

       *       *       *       *       *




CHAPTER I.

ON COLOURING.


How early, and to what extent, colouring may have attained the rank of
science among the ancients, are questions not easily set at rest; but
that some progress had been made, even at a very remote period, is
proved by the magnificent tombs of the Egyptian kings at Thebes, where
the walls of the royal mausoleum are described as being covered with
paintings so fresh and perfect, as to require neither restoration nor
improvement. So far from this, indeed, that with all care in copying, it
was difficult to equal the brilliancy of the originals, which, as far as
colours went, threw all others in the background. And yet, in spite of
the scale having comprised pure vermilion, ochres, and indigo, it was
not gaudy, owing to the judicious balance of the colours, and the
artful management of the black. Nor was there an ornament throughout the
dresses, wherein the red, yellow, and blue, were not so employed as to
produce a delicious harmony.

Moreover, it is stated that in one painting eighty feet high and
proportionably broad, which was divided into two ranges of gigantic
figures, these were glowing with most exquisite colours, suited to the
drapery and naked parts; and in which the azure, yellow, green, &c.,
were as well preserved as though they had been laid on yesterday. Again,
an apartment was discovered among the stupendous ruins at Carnac, on the
site of ancient Thebes, one hundred paces wide and sixty deep,
completely crowded with pillars, which, together with the ceiling, roof,
and walls, were decorated with figures in basso-relievo, and
hieroglyphics--all marvellously beautiful and finely painted, and as
fresh, splendid and glorious, after so many ages, as if they had just
been finished.

In various accounts these colourings of the Egyptians are described in
the warmest terms of admiration. The most charming are undoubtedly those
on the tombs and temples: others of less merit have been found on the
cases and cloths of mummies, and on papyrus rolls; but it is to the
patterns on the walls and ceilings of their houses that they seem to
have been most partial, and paid the most attention. The ordinary
colours employed by them were red, yellow, green, and blue. Of the last
there were two tints; black also was common. For white, the finely
prepared stone-coloured ground was deemed sufficient. These colours were
occasionally modified by mixture with chalk; but were always, or nearly
always, applied singly, in an unmixed state. With regard to their
composition, chemical analysis has shown several of the _blues_ to be
oxide of copper with a small proportion of iron; none containing cobalt.
There is little doubt, however, that the most brilliant specimens--those
which retain all their original force and beauty in the temples of Upper
Egypt after an exposure of three thousand years, consist of
ultramarine--the celebrated Armenian blue, possibly, of the ancients.
The _reds_ seem for the most part to be composed of oxide of iron mixed
with lime, and were probably limited to iron earths and ochres, with a
native cinnabar or vermilion. The _yellows_ are said to have been, in
many cases, vegetable colours; but it is likely earths and ochres were
their chief source. The _greens_ consist of yellow mixed with copper
blue. The bluish-green which sometimes appears on Egyptian antiquities,
is merely a faded blue. The _blacks_ are both of vegetable and mineral
origin, having been obtained from a variety of substances in a variety
of ways.

But, as shown by Layard in his discoveries at Nineveh, a knowledge of
colouring was not confined to the Egyptians; it was likewise possessed
by the Assyrians. The painted ornaments of the latter are stated to have
been remarkably elegant; and although the colours were limited to blue,
red, white, yellow, and black, yet they were arranged with so much taste
and skill, and the contrasts were so judiciously preserved, that the
combinations were in general agreeable to the eye. The pale
yellowish-white ground on which the designs were painted, resembled the
tint on the walls of Egyptian monuments, and a strong well-defined black
outline was found to be as peculiar a feature in Assyrian as in Egyptian
painting, black frequently combining with white alone, or alternating
with other colours. As far as they have been analysed, the pigments
employed were mineral, the brightest being a blue derived from copper.
No traces of vegetable colours have been found; it is presumed that they
existed, but being subject to more rapid decay than the mineral
pigments, they have disappeared. That all the colours, indeed, employed
by the ancients were not permanent, was proved by the fact of certain
blues and reds, brilliant and vivid when the earth was removed from
them, fading rapidly when exposed to the air.

From Philocles, the Egyptian, and Gyges, a Lydian, both of whom,
according to Pliny, acquired the knowledge of the art of painting in
Egypt, the Greeks obtained the knowledge of their _Ars Chromatica_,
which they are said to have carried by gradual advances during several
centuries, from the monochromatic of their earlier painters, to the
perfection of colouring under Zeuxis and Apelles, 450 to 350 B.C.
Unfortunately, not long after, or about 300 B.C., art rapidly
deteriorated; the invasion of the Romans commenced; and the principles
of light, shade, and colours in painting as understood by the Greeks,
together with their valuable treatises on the subject were lost. The
early Roman and Florentine painters, so eminent in other respects, were
almost destitute of those principles, and of truly refined feeling for
the effects of colouring.

The partial restoration of this branch seems to have been coeval with
the earliest practice of painting in oil. The glory of it belongs to the
Venetians, to whom the art of painting passed with the last remains of
the Greek schools after the capture of Constantinople at the beginning
of the thirteenth century. Giovanni Bellini laid the foundation of
colouring, and Titian carried it to its highest practical perfection.
From the Venetian it extended to the Lombard, Flemish, and Spanish
schools. In the practice of these, however, there was perhaps as much of
instinct as principle, colouring still remaining to be established in
its perfection as a science.

According to the true, natural, and philosophical classification of
painting, there are but three principal classes or schools; viz.: the
gross and _material_ which is content with mere nature, and to which
belong the Dutch and Flemish schools; the _sensible_, which aims at
refined and select nature, and accords with the Venetian school; and the
_intellectual_, which aspires to the ideal in beauty, grandeur, and
sublimity, and corresponds with the Greek, Roman, and Florentine
schools. Modern art as founded upon the _intellectual_ school of the
ancient Greeks, became grand, scientific, and severe in the practice of
Michael Angelo, and Leonardo da Vinci; graceful, beautiful and
expressive in Raphael, Correggio, Dominichino, and Guido; and, aiming at
_sensible_ perfection, it attained harmony of colouring and effect in
the works of Titian and Tintoret; but it sunk into grossness and
sensuality while perfecting itself _materially_ among the Flemish and
Dutch.

In the practice of the individual in painting, as well as in all
revolutions of pictorial art, in ancient Greece as in modern Italy,
colouring in its perfection has been the last attainment of excellence
in every school. It has been justly observed, indeed, that for near
three hundred years, since painting was revived, we could hardly reckon
six painters that had been good colourists, among the thousands who had
laboured to become such. But there is reason to hope that as Zeuxis
succeeded and excelled Polygnotus, and Titian Raphael, the artists of
Britain will transcend all preceding schools in the chromatic department
of painting. It is even probable that they may surpass them in all other
branches, and in every mode and application of the art, as they have
already more particularly done in an original and unrivalled use of
water-colours.

Happily, too, there has arisen among us a school of colouring that
confirms this expectation, strengthened as it is, by the suitableness of
our climate to perfect vision. For in it we have that mean degree of
light which is best adapted to the distinguishing of colours, a
boundless diversity of hue in nature relieved by those fine effects of
light and shade which are denied to more vertical suns, besides those
beauties of complexion and feature in our females peculiar to England;
respects in which at least our country is not unfavourable to art.

Even now it is urged by some to the _disparagement_ of the British
school, that it excels in colouring; as if this were incompatible with
any other excellence, or as if nature, the great prototype of art, ever
dispensed with it. The graphic branches of painting, owe everything to
colour, which, if it does not constitute a picture, is its flesh and
blood. Without it, the finest performances remain lifeless skeletons,
and yield no pleasure. Painting is the art of representing visible
things by light, shade, form, and colour; but of these, colour--and
colour alone--is the immediate object which attracts the eye. Colouring
is, therefore, the first requisite--the one thing imparting warmth and
life--the chief quality engaging attention; in short, the best
introduction to a picture, and that which continues to give it value so
long as it is regarded. It is a power, too, which is with the most
difficulty retained, being the first to leave the artist himself, and
the first to quit a school on its decline. Graphic art without
colouring, is as food without flavour; and it was the deficiency of
colouring in the great works of the Roman and Florentine schools that
caused Sir Joshua Reynolds to confess a certain want of attraction in
them. To relish and estimate truly their greatness, required, he said, a
forced and often-repeated attention, and "it was only those persons
incapable of appreciating such divine performances, who made pretensions
to instantaneous raptures on first beholding them." Gainsborough also,
with a candour similar to that of Reynolds, upon viewing the cartoons at
Hampton Court, acknowledged that their beauty was of a class he could
neither appreciate nor enjoy.

Colouring, then, is a necessity; but there is in it a vicious extreme;
that in which it is rendered so principal as, by want of subordination,
to overlay the subject. There is also a negative excellence which
consists in not always employing pleasing tints, but of sometimes taking
advantage of the effects to be derived from impure hues, as Poussin did
in his "Deluge." In this work, neither black nor white, blue, red, nor
yellow appears; the whole mass being, with little variation, of a sombre
grey, the true resemblance of a dark and humid atmosphere, by which
every object is rendered indistinct and almost colourless. This absence
of colour, however, is a merit, and not a fault. Vandyke employed such
means with admirable effect in the background of a Crucifixion, and in
his Pieta; and the Phaëton of Giulio Romano is celebrated for a
suffusion of smothered red, which powerfully excites the idea of a world
on fire.

Of the rank and value of this department of painting, there will be, as
there has been, difference of judgment and opinion, as there is variety
in the powers of the eye and understanding. But take from Rubens,
Rembrandt, Titian, and other distinguished masters, the estimation of
their colouring, and we fear all that is left to them would hardly
preserve their names from oblivion. Art cannot, indeed, attain its
appropriate end, that of pleasing, without excellence in colouring. It
is colour which the true artist most loves, and it is colouring in all
its complex and high relations, that he ever seeks to attain. Looking
above, and around, and beneath him, with the intelligent eye of the
colourist, he finds a boundless source of never-ceasing enjoyment. With
harmonies and accordances lost to the untutored gaze, colour meets him
in every stone he treads on--in the mineral, vegetable, and animal
creation--in the heavens, sea, and earth. For him, in truth, colour is
as equally diffused as light, spreading itself over the entire face of
nature, and clothing the whole world with beauty.




CHAPTER II.

ON THE RELATIONS AND HARMONY OF COLOUR.


Assured as we must be of the importance of colouring as a branch of art,
colours in all their bearings become interesting to the artist, and on
their use and arrangement his reputation as a colourist must depend.

Colour, remarks Ruskin, is wholly _relative_; each hue throughout a work
is altered by every touch added in other places. Thus, to place white
beside a colour is to heighten its tone; to set black beside a colour is
to weaken its tone; while to put grey beside a colour, is to render it
more brilliant. If a dark colour be placed near a different, but lighter
colour, the tone of the first is heightened, while that of the second is
lowered. An important consequence of this principle is, that the first
effect may neutralize the second, or even destroy it altogether. What
was cold before, becomes warm when a colder colour is set near it, and
what was in harmony before, becomes discordant as other colours are put
beside it. For example, to place a light blue beside a yellow, tinges
it orange, and consequently heightens its tone. Again, there are some
blues so dark relatively to the yellow that they weaken it, and not only
hide the orange tint, but even cause sensitive eyes to feel that the
yellow is rather green than orange--a very natural result when it is
considered that the paler the yellow becomes, the more it tends to
appear green.

We learn from these relations of colours, why dapplings of two or more
produce effects in painting so much more clear and brilliant than
uniform tints obtained by compounding the same colours: and why
hatchings, or a touch of their contrasts, thrown as it were by accident
upon local tints, have the same effect. We see, too, why colours mixed
deteriorate each other, which they do more--in many cases--by
imperfectly neutralizing or subduing each other chromatically, than by
any chemical action. Finally, we are impressed with the necessity, not
only of using colours pure, but of using pure colours; although pure
colouring and brilliancy differ as much from crudeness and harshness, as
tone and harmony from murkiness and monotony.

The powers of colours in contrasting each other agree with their
correlative powers of light and shade, and are to be distinguished from
their powers individually on the eye, which are those of light alone.
Thus, although orange and blue are equal powers with respect to each
other, as regards the eye they are totally different and opposed. Orange
is a luminous colour, and has a powerfully irritating effect, while blue
is a shadowy colour, possessing a soothing quality--and it is the same,
in various degrees, with other colours.

There are yet further modes of contrast or antagonism in colouring,
which claim the attention and engage the skill of the colourist. Of the
contrast of _hues_, upon which depend the brilliancy, force, and harmony
of colouring, we have just spoken; but there is, secondly, the contrast
of _shades_. To this belong all the powers of chiaroscuro, by which term
the painter denotes the harmonious effects of light and shade; and
though they form the simplest part of colouring, yet they cannot be
separated from it--light and shade, the chiaroscuro, being a distinct
and important branch of painting. A third mode of contrast in colouring
is that of _warmth_ and _coolness_, upon which depend the toning and
general effect of a picture. Fourthly, there is the contrast of _colour_
and _neutrality_, the chromatic and achromatic, or hue and shade. By the
right management of this, local colours acquire value, gradation,
keeping, and connection: whence come breadth, aërial perspective, and
the due distribution of greys and shadows in a picture.

This principle of contrast applies even to _individual colours_, and
conduces greatly to good colouring. It may be carried with advantage
into the variety of hue and tint in the same colour, not only as regards
light and shade, but likewise with respect to warmth and coolness, as
well as to colour and neutrality. Hence the judicious landscape-painter
knows how to avail himself of warmth and coolness in the juxtaposition
of his greens, in addition to their lightness and darkness, or
brilliancy and brokenness, in producing the most beautiful and varied
effects; effects which spring in other cases from a like management of
blue, white, &c. These powers of a colour upon itself are highly
important to the artist, and lead to that gratification from fine
colouring, which a good eye ever enjoys.

In landscape we see nature employing broken colours in harmonious
consonance and variety, while, equally true to picturesque relations,
she uses also broken forms and figures, in conjoint harmony with
colours; occasionally throwing into the composition a regular form, or a
primary colour, for the sake of animation and contrast. And if we
inspect her works more closely, we shall find that they have no uniform
tints. Whether in the animal, vegetable or mineral creation--flesh or
foliage, earth or sky, flower or stone--however uniform the colour may
appear at a distance, it will, when examined nearly, be found to
consist of a variety of hues and shades, compounded with harmony and
intelligence.

It is for this reason that no two colours are ever found discordant in
nature, however much so they may be in art. Blue and green have been
termed discordant, and in painting they may undoubtedly be made so. Yet
those are two colours which nature seems to intend never to be
separated, and never to be felt, either of them, in its full beauty,
without the other--a blue sky through green leaves, or a blue wave with
green lights through it, being precisely the loveliest things, next to
clouds at sunrise, in this coloured world of ours. A good eye for colour
will soon discover how constantly nature puts green and purple together,
purple and scarlet, green and blue, yellow and neutral grey, and the
like; and how she strikes these colour-concords for general tones,
before working into them with innumerable subordinate ones.

Upon the more intimate union, or the blending and gradience of contrasts
from one to another mutually, depend some of the most fascinating
effects of colouring. The practical principle employed in producing them
is important, and consists in the blending and gradating by _mixture_,
while we avoid the _compounding_ of contrasting colours. That is, the
colours must be kept distinct in the act of blending them, or otherwise
they will run into dusky neutrality and defile each other. This is the
case in blending and gradating from green to red, or from hue to
hue--from blue to orange, or to and from coldness and warmth--from
yellow to purple, or to and from advancing and retiring colours. It is
the same in light and shade, or white and black, which _mix_ with
clearness. Now, there are only two ways in which this distinctness in
union of contrasts can be effected in practice: the one is by hatching
or breaking them together in mixture, without compounding them
uniformly; and the other is by glazing, in which the colours unite and
penetrate mutually, without monotonous composition.

The former process may be said to be the carrying out of the principle
of separate colours to the utmost possible refinement, by using atoms of
colour in juxtaposition, instead of in large spaces. And it is to be
noted, in filling up minute interstices of this kind, that if the colour
with which they are filled be wanted to show brightly, a rather positive
point of it had better be put, with a little white left beside or round
it in the interstice. This plan is preferable to laying a pale tint of
the colour over the whole interstice. Yellow or orange, for instance,
will hardly show, if pale, in small spaces; but they show brightly in
free touches, however small, with white beside them. The latter mode is
founded on the fact, that if a dark colour be laid first, and a little
blue or white body-colour struck lightly over it, a more beautiful gray
will be obtained than by mixing the colour and the blue or white.
Similarly, if over a solid and perfectly dry touch of vermilion there be
quickly washed a little very wet carmine, a much more brilliant red will
be produced than by mixing the two colours.

Transparency and opacity constitute another contrast of colouring, the
former of which belongs to shade and blackness, the latter to light and
whiteness. Even contrast has its contrast, for _gradations_ or
_intermedia_ are opposed to contrasts or _extremes_; and, upon the right
management of contrasts and gradations depend the harmony and melody,
the tone, effect, and general expression of a picture. Thus, painting is
an affair of judicious contrasting so far as regards colour, if even it
be not such altogether.

Colour, it has already been observed, is wholly _relative_. In
contrasting, therefore, any colour, if we wish it to have light or
brilliancy, we cast its opposite into the shade; if we would have it
warm, we cool its antagonist; and if transparent, we oppose it by an
opaque contrary, and _vice versâ_: indeed, in practice, all these must
be in some measure combined.

Such are some of the powers of contrast in colouring alone, and such is
the diversity of art upon which skill in colouring depends. It must not
be forgotten, however, that contrasts or extremes, whether of light and
shade, or of colours, become violent and offensive when they are not
reconciled by the interposition of their media, or intermediates, which
partake of both extremes of the contrasts. Thus blue and orange in
contrast become reconciled, softened in effect, and harmonized, when a
broken colour composed of the two intervenes. The same may be said of
other colours, shades, and contrasts.

Seeing that the management and mastery of colours are to a great extent
dependent on the same principles as light and shade, it might become a
point of good discipline, after acquiring the use of black and white in
the chiaroscuro, to paint designs in contrast; that is, with two
contrasting colours only, in conjunction with black and white--for
example, with blue and orange, before attempting the whole. Indeed,
black can be dispensed with in these cases, because it may be
compounded, since the neutral grey and third colours always arise from
the compounding of contrasting colours. In this way, even flesh may be
painted--for instance, with red and green alone, as Gainsborough is said
at one period to have done.

Some artists have produced pictures in the above hot and cold colours
only; which, although captivating to the eye, and true in theory with
respect to colour, light and shade, are generally false in practice with
regard to nature, which rarely employs such extreme accordances.
Colouring like this, therefore, is more beautiful than true. It is as
though a painter were to execute a landscape in the full light of day,
as he saw it looking through a prism, so that every object glowed with
rainbow hues. Such a picture would present a beautiful fairy scene, and
be true as regards colours, but as respects nature, it would be false.

Colour, and what in painting is called transparency, belong chiefly to
shade. It has been a common error to ascribe those properties to light
only, and hence many have employed a uniform shade tint, regarding
shadows as simply darkness, blackness, or the mere absence of light;
when, in truth, shadows are infinitely varied by colour, and always so
by the colours of the lights which produce them. But while we incline
attention toward the relation of colour to shade, both light and shade
being strictly co-essential to colour, a vicious extreme must be
avoided. For although, as transparent, colour inclines to shade, and, as
opaque, it partakes of light; yet the general tendency of colour is to
transparency and shade, all colour being a departure from light. Hence
it becomes a maxim, which he who aspires to good colouring must never
lose sight of, that _the colour of shadow is always transparent, and
only that of extreme light objects opaque_. It follows, that white is to
be kept as much as possible out of shadow, and black, for the same
reason, out of colour. In their stead, whenever it is necessary to
cover, opaque tints may be employed, glazed over with transparent
colours. Such practice would also be more favourable to durability of
the tones of pictures, than the shades and tints produced with black and
white. The hues and shadows of nature are in no ordinary case either
black or white, which, except as local colours, are always poor and
frigid. The perfection of colouring is to combine harmony with
brilliancy, unity with variety, and freshness with force, without
violating the laws of nature.

With regard to the _perspective of colours_, or the manner in which they
affect the eye, according to position and distance, it is a branch of
aërial perspective or the perspective of light and shade. This is
distinguished from linear perspective, or the perspective of drawing, as
drawing is from colouring; and they have progressed alike in the art.
The most ancient painters seem to have known little of either; and
linear perspective was established as science before the aërial, as
drawing and composition preceded colouring.

The perspective of colours depends upon their powers to reflect the
elements of light, powers which are by no means uniform. Accordingly,
blue is lost in the distance before red, and yellow is seen at a point
at which red would disappear; yet blue preserves its hue better than
yellow, because colours are cooled in the distance. In this respect,
the compound colours partake of the powers of their components, in
obedience to a general rule, by which local colours closely connected
with black are first lost in the distance, and those nearly related to
white disappear last. The same may be said of local light and shade, the
latter of which is totally lost at great distances; and it is for this
reason the shadowed side of the moon is not generally seen. These powers
of colours are, however, varied by mist, air, altitude, and mixture,
which produce evanescence; and by contrast, which preserves the force of
colours by distinguishing them. Colours do not decline in force so much
by height as by horizontal distance, because the upper atmosphere is
less dense and clouded with vapour: and hence it is that mountains of
great elevation appear much nearer than they really are. From all these
circumstances, it is evident that a simple scumbling or uniform
degradation of local colours will not effect a true perspective--for
this will be the aërial of light and shade only--but such a
subordination of hues and tints, as the various powers of colours
require, and as is always observable in nature.

In furnishing or _setting the palette_ philosophically and upon
principle, it is necessary to supply it with pure blue, red, and yellow;
to oppose to these an orange, of a hue that will neutralise the
blue--green, of a hue that will neutralise the red--and purple, of a hue
that will neutralise the yellow; and so on to black and white, which
will neutralise each other. As in nature, the general colour of the sky
is blue, and the colour of light is always opposite to that of the sky
and shade, so the white which is to represent light should be tinged
with the orange of the palette sufficiently to neutralise the
predominant coldness of black. Pure neutral white may thus be reserved
as a "local" colour, which is a technical term for the _natural_ colour
of an object, unvaried by distance, reflection, or anything interfering
with distinct vision; although, properly speaking, local colours are
subject to all the relations and effects of the places they occupy in a
composition--whether of light, shade, reflection, or distance.

From what we have said, it will be seen that the relations and harmony
of colours form a complex subject, requiring constant and careful study;
one, indeed, into which he who would become a colourist must enter heart
and soul. For as colouring is the beginning and end of a painter's
craft, so colour in all its aspects must be the chief lesson of his
life. And this lesson can only be learnt, by ever watching with a loving
eye those wondrous colourings of nature, in which there is nothing
inharmonious or out of place.




PART II.

       *       *       *       *       *

ON COLOURS AND PIGMENTS GENERALLY.




CHAPTER III.

ON CLASSES OF COLOURS.


By mixing his _colours with white_, the artist obtains his _tints_. By
mixing _colours with colours_, he produces compound colours, or _hues_.
And by mixing _colours or tints with black_, he gets _shades_. It is a
common error to confound these distinctions.

The above classification of colours enables us to understand the
simplicity of relation which exists among an infinity of tints, hues,
and shades of colour. Also, it is calculated to give precision to
language respecting colours, the nomenclature of which has too often
been vague and uncertain.

There are five classes of colours, viz.:--the _Neutral_, the _Primary_,
the _Secondary_, the _Tertiary_, and the _Semi-neutral_.

_Neutral Colours_ are three only, _white_, _black_, and grey. According
to the laws of Optics, the two first comprise all other colours
synthetically, and afford them all by analysis. These are sometimes
called "extreme" colours, grey being their intermediate.

_Primary Colours_ are three only, _yellow_, _red_, and _blue_. They are
such as yield others by being compounded, but are not themselves capable
of being produced by composition of other colours. By way of
distinction, they are occasionally designated "entire" colours.

_Secondary Colours_, are three only, _orange_, _green_, and _purple_.
Each of these is composed of, or can be resolved into, two primaries.
Thus, orange is composed of red and yellow; green, of yellow and blue;
and purple, of blue and red.

_Tertiary Colours_ are three only, _citrine_, _russet_, and _olive_.
Each of these is composed of, or can be resolved into, either two
secondary colours, or the three primaries. Thus, citrine consists of
green and orange, or of a predominant yellow with blue and red; russet
is compounded of orange and purple, or of a predominant red with blue
and yellow; and olive is composed of purple and green, or of a
predominant blue with yellow and red.

The last three genera of colours comprehend in an orderly gradation all
those which are _positive_ or definite; and the three colours of each
genus, united or compounded in such subordination that neither of them
predominates to the eye, constitute the _negative_ or neutral colours,
of which _black_ and _white_ have been stated to be the opposed
extremes, and _greys_ their intermediates. Thus black and white are
constituted of, and comprise latently, the principles of all colours,
and accompany them in their depth and brilliancy as shade and light.

_Semi-neutral Colours_ belong to a class of which _brown_, _marrone_,
and _gray_ may be considered types. They are so called, because they
comprehend all the combinations of the primary, secondary, and tertiary
colours, with the neutral _black_. Of the various combinations of black,
those in which yellow, orange, or citrine predominates, have obtained
the name of brown, &c. A second class in which the compounds of black
are of a predominant red, purple, or russet hue, comprises marrone,
chocolate, &c. And a third class, in which the combinations of black
have a predominating hue of blue, green, or olive, includes gray, slate,
&c.

While treating of the classes of colours, it may not be out of place to
note here the difference between gray as spelt with an _a_, and grey as
spelt with an _e_, the two names being occasionally confounded. _Gray_
is semi-neutral, and denotes a class of cool cinereous colours, faint of
hue; whence we have blue grays, olive grays, green grays, purple grays,
and grays of all hues in which blue predominates; but no yellow or red
grays, the predominance of such hues carrying the compounds into the
classes of brown and marrone, of which gray is the natural opposite.
_Grey_ is neutral, and is composed of or can be resolved into black and
white alone, from a mixture of which two colours it springs in an
infinite series.

It must be observed that each colour may comprehend an indefinite series
of _shades_ between the extremes of light and dark, as each compound
colour also may comprise a similar series of _hues_ between the extremes
of the colours composing it. And as the relations of colours have been
deduced regularly, from white or light to black or shade; so the same
may be done, inversely, from black to white. On this plan the
tertiaries, olive, russet, and citrine, take the place of the primaries,
blue, red, and yellow; while the secondaries still retain their
intermediate station and relation to both.

Thus, _russet and olive_ compose or unite in _dark purple_; _citrine and
olive_ in _dark green_; _russet and citrine_ in _dark orange_. The
tertiaries have, therefore, the same order of relation to black that the
primaries have to white; and we have black primaries, secondaries, and
tertiaries, inversely, as we have white primaries, secondaries, and
tertiaries, directly. In other words, we have light and dark colours in
all classes.




CHAPTER IV.

ON THE DURABILITY AND EVANESCENCE OF PIGMENTS.


Pigments may be defined as colours in a solid or insoluble state,
prepared for the artists' use. Hitherto, we have treated of colours in
the abstract sense, as appealing to the eye only: we have now to
consider them as material bodies.

As colour itself is relative, so is durability of colour relative. For
the reason that all material substances are changeable and in perpetual
action and reaction, no pigment is so permanent as that nothing will
alter its colour. On the other hand, none is so fugitive as not to last
under some favouring circumstances. Time, of long or short continuance,
has often the effect of fire, more or less intense. Indeed, it is some
sort of criterion of the stability and changes of colour in pigments,
that time and fire are apt to produce similar effects thereon. Thus, if
fire deepen, or cool, or warm a colour, so may time; if it vary its
hues, so may time; if it destroy a colour altogether, so may time
ultimately. The power of time, however, varies extremely with regard to
the period in which it produces those effects, that are instantly
accomplished by fire.

That there is no absolute but only relative durability of colour may be
proved from the most celebrated pigments. For instance, the colour of
native ultramarine, which will endure a hundred centuries under ordinary
circumstances, may be at once destroyed by a drop of lemon juice; and
the generally fugitive and changeable carmine of cochineal will, when
secluded from light and air, continue fifty years or more; while fire or
time, which merely deepen the former colour, will completely dissipate
the latter. Again, there have been works of art in which the white of
lead has retained its freshness for ages in a pure atmosphere, but has
been changed to blackness after a few days' or even hours' exposure to
foul air. These and other peculiarities of colours will be noticed, when
we come to speak of pigments individually; not for the purpose of
destroying the artist's confidence, but as a caution, and a guide to the
availing himself of their powers properly.

It is, therefore, the lasting under the usual conditions of painting,
and the common circumstances to which works of art are exposed, that
entitles a colour to the character of permanency; and it is the
not-so-enduring which attaches to it rightly the opposite character of
evanescence: while a pigment may obtain a false repute for either, by
accidental preservation or destruction under unusually favourable or
fatal circumstances.

Many have imagined that colours vitrified by intense heat are
consequently durable when levigated for painting in oil or water. Had
this been the case, the artist need not have looked farther for the
furnishing of his palette than to a supply of well-burnt and levigated
enamel pigments. But though such colours for the most part stand well
when fluxed on glass, or in the glazing of enamel, they are nearly,
without exception, subject to the most serious changes when ground to
the degree of fineness necessary to their application as pigments, and
become liable to all the chemical changes and affinities of the
substances which compose them. These remarks even apply in a measure to
native products, such as coloured earths and metallic ores.

Others have not unreasonably supposed that when pigments are locked up
in varnishes and oils, they are safe from all possibility of change. The
assumption would be more warranted if we had an impenetrable
varnish--and even that would not resist the action of light, however
well it might exclude the influence of air and moisture. But, in fact,
varnishes and oils themselves yield to changes of temperature, to the
action of a humid atmosphere, and to other influences: their protection
of colour from change is therefore far from perfect.

Want of attention to the unceasing mutability of all chemical
substances, as well as to their reciprocal actions, has occasioned those
changes of colour to be ascribed to fugitiveness of the pigment, which
belong to the affinities of other substances with which it has been
improperly mixed and applied. It is thus that the best pigments have
suffered in reputation under the injudicious processes of the painter;
although, owing to a desultory practice, the effects and results have
not been uniform. If a colour be not extremely permanent, dilution will
render it in some measure more weak and fugitive; and this occurs in
several ways--by a too free use of the vehicle; by complex mixture in
the formation of tints; by distribution, in glazing or lackering, of
colours upon the lights downward, or scumbling colours upon the shades
upward; or by a mixed mode very common among the Venetian painters, in
which opaque pigments are combined, as umber and lake.

The fugitive colours do less injury in the shadows than in the lights of
a picture, because they are employed pure, and in greater body in
shadows, and are therefore less liable to decay by the action of light,
and by mixture. Through partially fading, moreover, they balance any
tendency to darken, to which the dead colouring of earthy and metallic
pigments is disposed.

The foregoing circumstances, added to the variableness of pigments by
nature, preparation, and sophistication, have often rendered their
effects equivocal, and their powers questionable. These considerations
enforce the expediency of using colours as pure and free from
unnecessary mixture as possible; for simplicity of composition and
management is equally a maxim of good mechanism, good chemistry, and
good colouring. Accordingly, in respect to the latter, Sir Joshua
Reynolds remarks, "Two colours mixed together will not preserve the
brightness of either of them single, nor will three be as bright as two:
of this observation, simple as it is, an artist who wishes to colour
bright will know the value."

There prevail, notwithstanding, two principles of practice on the
palette, opposed to each other--the one, simple; the other, multiple.
The first is that of having as few pigments as possible; and consists,
when carried to the extreme, in employing the three primary colours
only. The second is that of having a number of pigments; and consists,
also when carried to the extreme, of employing as many, if possible, as
there are hues and shades of colour.

On the former plan, every tint requires to be compounded; on the latter,
one pigment supplies the place of two or more. Now, the more pigments
are mixed, the more they are deteriorated in colour, attenuated, and
chemically set at variance. Original pigments, that is, such as are not
made up of two or more colours, are purer in hue and generally more
durable than those compounded. Hence pure intermediate tints in single,
permanent, original pigments, are to be preferred to pigments
compounded, often to the dilution and injury of their colours. Cadmium
Orange, for instance, which is _naturally_ an orange pigment and not
composed of red and yellow, is superior to many mixtures of those
colours in a chemical sense, and to all such mixtures in an artistic
sense. At the same time, it is quite possible for the artist to multiply
his pigments unnecessarily. Colours are sometimes brought out under new
names which have no claim to be regarded as new colours, being, indeed,
mere mixtures. Compound pigments like these may most frequently be
dispensed with, in favour of hues and tints composed extemporaneously of
original colours upon the palette.

It may be inferred from the foregoing that, between the modes of
employing as few pigments as possible, and of having as many as there
are hues and shades of colour, a middle course is the best. But,
whatever the practice adopted, permanent _original_ pigments should be
used as often as the case will admit; it being borne in mind, that a
pigment may be compound, although its colour may be primary. As a rule,
the less colours are mixed, the purer, brighter, and more lasting they
will be found.

To the practice of producing tints and hues by _grinding_ pigments
together, instead of _blending_ them on the palette, may be attributed
some of the peculiarities of the tints and textures of the Flemish
school; they being, perhaps, results of intimate combination from
grinding, and consequently of a more powerful chemical action among the
ingredients compounded. This method has, in a great measure, fallen into
disuse, and undoubtedly it conduced to foulness when the colours of the
pigments ground were not pure and true, and did not assimilate well in
mixture chemically.

The superiority of Rubens and the Flemings, and of Titian and the
Venetian school, in colouring and effect, is due in a considerable
degree to their sketching their designs in colours experimentally with a
full palette. This practice, as derived from Reynolds, is common with
the best masters of our own school, who, in executing their works,
resort also to nature, with an improved knowledge of colours and
colouring. Such attention to colouring and effect, from the first study
and ground of a picture to the finishing, contributes a beauty to the
painting no superinduced colouring can accomplish.

The durability of colour in substances is to a great extent dependent
upon the condition in which they exist chemically. If pigments, for
example, be in a state which chemists have termed _pro_toxide, they are
liable to absorb oxygen on exposure to light, air, or moisture, and
becoming what is called _per_oxidized, may, by consequence, change or
fade. In like manner, lakes and carmines thrown down upon a base, may
owe some of their fugacity to the oxidation of that base, as well as to
the natural infirmity of their colouring matter. On the other hand,
pigments and bases are subject to _de_oxidation, or to a loss of oxygen,
in which case the colour is apt to deepen. Pigments generally are more
affected by oxidation and fading in a water vehicle, and by deoxidation
and darkening in one of oil.

A principal test of permanency in pigments is the impunity with which
they bear exposure to light and air, an artistic proof of their
stability the mere chemist is apt to neglect. Provided the colour remain
unaffected by sulphuretted hydrogen, &c., he seldom hesitates to
pronounce it safe. But a pigment may be fast in one sense and fugitive
in another, believed in by the laboratory, and found wanting by the
studio. It has happened before now that the same colour has been dubbed
durable and the reverse, by the man of science and the man of art. The
former, we take it, looks upon a pigment as a coloured substance of a
certain composition, possessing maybe an acid and a base, either, or
neither, or both of which, gases and other reagents may injure or
destroy. The latter views a colour chiefly as part and parcel of his
picture--that picture which _may_ meet with foul exhalations, but _must_
be exposed to light and air. And he too often thinks as little of the
effects of an impure atmosphere or injudicious admixture, as the chemist
considers the action of air and light.

With the exception of madder, those colours mostly affected by _light
and air_ are of organic origin, such as gallstone, Indian yellow, and
the yellow dye-wood lakes; the red and purple lakes of cochineal;
indigo; and sap green. To these may be added the semi-organic Prussian
blue; and the inorganic yellows and orange of arsenic.

The pigments liable to injury from _sulphuretted hydrogen_, &c., are
notably those obtained from lead and copper; and that treacherous
compound of iodine and mercury, known as pure scarlet.

Many colours are apt to change from the action of white _lead_ and other
lead pigments, &c., principally those which are altered by light and
air.

Many, too, cannot safely come into contact with iron, or ferruginous
pigments; especially the yellows of arsenic, the lakes of cochineal, and
the blues and greens of copper. With these an iron palette knife is best
avoided, one of ivory or horn being used instead. The latter, indeed, is
preferable in all cases, several pigments being slightly affected by
iron, cadmium yellow among the number.

Numerous colours are likewise injured by _lime_ and _fire_, and cannot
therefore be employed in fresco, or enamel painting.

Of substances which may act deleteriously on colours, there remain the
_vehicles and varnishes_ with which they are mixed. Many of these have
been blamed, and often with justice, for their injurious effects on
pigments. The reputation of the most permanent colour may be ruined, if
the vehicle, &c., employed with it be untrustworthy. The presence of
lead, for instance, in such materials renders them liable to be
blackened by foul air, and by consequence the pigments used therewith.

Time produces in many cases a mellow and harmonious change in pictures,
but occasionally alterations altogether unfavourable. To ensure the
former and prevent the latter, the attention of the artist in the course
of his colouring should be to the employment of such pigments and
colours as are prone to adapt themselves, in changing, to the intended
key of his colouring, and the right effect of his picture. Thus, if he
design a cool effect, ultramarine has a tendency through time to
predominate and aid the natural key of blue. He will, therefore,
compromise the permanence of this effect, if in such case he employ a
declining or changeable blue, or if he introduce such reds and yellows
as have a tendency to warmth or foxiness, by which the colouring of
many pictures has been destroyed. In a glowing or warm key, the case is
in some measure reversed--not wholly so, for it is observable that those
pictures have best preserved their colouring and harmony in which the
blue has been most lasting, by the pigment counteracting the change of
colour in the vehicle, and that suffusion of dusky yellow which time is
wont to bestow upon pictures even of the best complexion.

Unless introduced and guaranteed by houses of acknowledged reputation,
newly discovered pigments are to be used with caution. Good colours have
ever been prized with so true an estimation of their value, that to
produce such, after so many ages of research is no ordinary
accomplishment. But too many resplendent pigments, fruits of the
fecundity of modern chemistry, have been found deficient. The yellow and
orange chromates of lead, for instance, withstanding as they do the
action of the sunbeam, become by time, foul air, and the influence of
other pigments, inferior to the ochres. So the dazzling scarlet of
iodine and mercury must yield the palm of excellence to the more sober
vermilion, being a chameleon colour, subject to the most sudden and
opposite changes. And the blues of cobalt, as always tending to
greenness and obscurity, cannot rank beside ultramarine.

We are far from asserting, however, that all modern pigments are
inferior, or that pigments should be looked upon with suspicion because
they are modern. Several most valuable colours have lately claimed
attention, notably the permanent transparent yellow called _Aureolin_.
Seeing that, until its introduction, a yellow combining transparency
with a perfect stability was unknown to the palette, the importance of
such an addition, so long wanted and wished for, cannot be overrated.
Equal in beauty and durability with the preceding, but possessing
greater richness and depth, and of a semi-opacity, another yellow of the
highest order merits regard, _Orient Yellow_, distinguished for its
lustrous golden hue, resembling a bright Indian yellow. Dazzling in
brilliancy, and absolute in permanency. _Cadmium Red_ next attracts
notice. This new aspirant for artistic fame is a most vivid
orange-scarlet, the latter colour predominating, of intense fire, but
with no approach to rankness or harshness, yielding delicate pale
washes, and blending happily with white in the formation of flesh tints.
With it may be coupled _Cadmium Orange_, a colour equally brilliant and
stable, and equally without rankness or harshness, but of a true orange
hue, admirably adapted for sunsets and the like. Last of all the fresh
pigments of whose thorough durability there is _no_ doubt, comes the
splendid _Viridian_, a green nothing but fire will change, and no
mixture of blue and yellow will afford. Clear, bright, and transparent
as the emerald, it rivals velvet in its soft gorgeous richness. With
this and Aureolin a series of beautiful foliage tints may be formed,
sparkling with sunshine, as it were.

Other colours there are which have been brought forward within the last
few years, not possessing the absolute permanency of the five foregoing,
but equal, or superior, to many formerly used. It were folly, therefore,
and a silly conservatism on the part of the artist to limit himself to
such pigments only as were employed by his forefathers, especially as
their merits were often more than doubtful. New colours, it is true,
have to be _learnt_, for each pigment has its own peculiar habitudes,
chemical, physical, artistic; but if they be good and durable, no amount
of time and study spent upon them is thrown away. To think less of the
quality of one's materials than of the effects which can be produced
with them is mistaken policy; and to be content with that quality when
better can be had, shows no real love of art, but rather indolence and
apathy.

Perhaps one reason why freshly introduced pigments have not as fair a
chance as they are entitled to, is due to the fashion which prevails of
exclaiming against the fugacity of modern colours. If their detractors
would confine themselves to certain colours, there could be no denial;
but to assert, as is often done, that the cause of modern pictures not
standing is owing to modern pigments generally, is unjust. It is not
the materials which should be blamed, but those who use them. The fact
is, that the artist's knowledge has not increased in proportion to the
greater variety of colours at his command. In the early periods of art,
when the palette was chiefly confined to native pigments, the painter
could not very well go wrong. Now-a-days but too many, wanting the skill
of the old masters, seek to make amends for it by brilliancy of
colouring: with imperfect knowledge of their materials the result is
obvious. The palette, we admit, wants weeding; not only of the bad new
colours, but of the bad old colours. This, however, must be a work of
time, and depend, not upon the colourman--for where there is a demand
there will be a supply--but upon the artists themselves. To this end an
increased acquaintance with the properties of pigments is required,
whereby they may be able to choose the fast from the fugitive. It may be
fairly assumed that the painter will be assisted in his task by the
progress of chemical science, which will doubtless add from time to time
to the list of stable pigments. We have heard it remarked that there are
too many colours already--to which we reply, there are not too many good
colours, and scarcely can be. The more crowded the palette is with
reliable pigments, the more likely are the worthless to be pushed from
their places. In our opinion, there is ample room for fresh colours,
provided they be durable; and we have as little sympathy with the
stereotyped cry of there being too many, as with the fashionable
unbelief in modern pigments. Certainly, the artist who seeks for
permanence among the whites, reds, or blues, will not be troubled with a
superfluity. Certainly, too, colours are as good as ever they were, and
better--better made, better ground, better prepared for use. But, fast
and fugitive, pigments are more numerous, and for that reason need more
careful selection.




CHAPTER V.

ON THE GENERAL QUALITIES OF PIGMENTS.


The general attributes of a perfect pigment are beauty of colour,
comprehending pureness and richness, brilliancy and intensity, delicacy
and depth,--truth of hue--transparency or opacity, well-working,
crispness, setting up, or keeping its place, and desiccation, or drying
well. To all of these must be superadded _durability_ when used, a
quality to which the health and vitality of a picture belong, and one so
essential that all other properties put together without it are of no
esteem with the artist who merits reputation. We have, therefore, given
it a previous distinct consideration.

It must be observed that no pigment possesses all the foregoing
qualifications in perfection, some being naturally at variance or
opposed; nor is there any, perhaps, that cannot boast excellence in one
or more of them.

_Beauty_ commonly comprises in the same pigment delicacy, purity, and
brilliancy; or depth, richness, and intensity. Delicacy and depth in
the beauty of colours are at variance in the production of all pigments,
so that perfect success in producing the one is attended with more or
less of failure in the other, and when they are united--as they
occasionally are--it is with some sacrifice of both. Hence the judicious
artist purveys for his palette at least two pigments of each colour, one
eminent for delicate beauty, the other for richness and depth.

_Truth of hue_ is a relative quality in all colours, except the extreme
primaries, in the relations of which, blue, being of nearest affinity to
black or shade, has properly but one other relation, in which it
inclines to red and becomes purple-blue: it is, therefore, faulty or
false, when, tending to yellow, it becomes of a green hue. But red,
which is of equal affinity to light and shade, has two relations, by one
of which it verges upon blue and becomes a purple-red or crimson; and by
the other it leans to yellow, and becomes an orange-red or scarlet,
neither of which is individually false or discordant. Yet yellow, which
is of nearest affinity to white or light, has strictly but one true
relation, by which it inclines to red, and becomes a warm or orange
yellow, for by uniting with blue it becomes a defective green-yellow.
The best example of true yellow in a pigment, tending neither to red nor
blue, is furnished by _Aureolin_, alluded to in the last chapter. The
secondary and tertiary colours, having all duplex relations, may
incline without default to either of their relatives.

_Transparency_ is an essential property of all glazing pigments, and
adds greatly to the value of dark or shading colours; indeed it is the
prime quality upon which depth and darkness depend, as whiteness, or
light, does upon opacity or reflecting power. _Opacity_ is, therefore,
the antagonist of transparency, and qualifies pigments to cover in
dead-colouring, or solid painting, as well as to combine with
transparent colours in forming tints; and hence it is that
semi-transparent pigments are suited in a mean degree both for dead
colouring and for finishing. As excellencies, therefore, transparency
and opacity are relative only--the first being as indispensable to shade
in all its gradations, as the latter is to light. With regard to
transparent and opaque colours generally, it is worthy of attention in
the practice of the oil-painter, that the best effects of the former are
produced when they are used with a resinous varnish; as opaque pigments
are best employed in oil, and the two become united with best effect in
a mixture of these vehicles. The natural and artificial powers, or depth
and brilliancy, of every colour lie within the extremes of black and
white; hence it follows that the most powerful effects of transparent
colours are obtained by glazing them over black and white. As, however,
few transparent pigments have sufficient body, or tinging power for
this, it is often necessary to glaze them over tints, or deep opaque
colours of the required hues. There is a charm in transparent colours
which frequently leads to an undue use thereof in glazing; but glazing,
scumbling, and their combined process must be employed with discretion,
according to the objects and effects of a picture.

_Working well_ is a quality which depends principally upon fineness of
texture, and what is called _body_ in colours; yet every pigment has its
peculiarities in respect to working both in water and oil, and these
must become matter of every artist's special experience. Some of the
best pigments are most difficult of management, while some ineligible
colours are rich in body and free in working. Accidental circumstances,
however, may influence all pigments in these respects, according to the
painter's particular mode of operation, and his vehicle; upon the
affinities of colours with which depend their general faculties of
working--such as keeping their place, crispness or setting up, and
drying well. These latter, with other properties and accidents of
pigments, will be particularly considered in treating of their
individual characters; but it may be remarked that crispness or setting
up, as well as keeping their place and form in which they are applied,
are contrary to the nature of many pigments, and depend in painting with
them upon a gelatinous mixture of their vehicle. For example, mastic
and other resinous varnishes impart this texture to oils which have been
rendered drying by the acetate, or sugar of lead:--simple water, also
albumen, and animal jelly made of glue and isinglass, give the same
quality to oils and colours; and bees-wax has a similar effect in pure
oils. Whitelac varnish, and other spirit varnishes, rubbed into the
colours on the palette likewise enable them to keep their place very
effectually in most instances. This is important, because glazing cannot
be performed except with a vehicle which keeps its place, or with
pigments which lend this property to the vehicle, as some lakes and
transparent colours do.

_Fineness of texture_ is produced by extreme grinding and levigation.
Pigments ground in water in the state of a thick paste, are miscible in
oil and dry therein firmly; and in case of utility or necessity, any
water-colour in cake, being rubbed off thick in water may be diffused in
oil, the gum acting as a medium of union between the two. Thus, pigments
which cannot otherwise be employed in oil, or varnish, may be forced
into the service and add to the resources of the oil-painter, care being
taken to use the palette-knife, if of steel, with caution.

_Desiccation or drying._ The well-known additions of the acetate, or
sugar of lead, litharge, and sulphate of zinc, either mechanically
ground, or in solution, for light colours; and japanner's gold size, or
oils boiled upon litharge, for lakes; or, in some cases, manganese and
verdigris for dark colours, are resorted to when the pigments or
vehicles are not sufficiently good dryers alone. It would be well if
lead and copper could be banished from the list of siccatives
altogether: assuredly, no artist with any regard for the permanent
texture of his work should employ them except in extreme cases, and in
the smallest possible quantity. The best of pigments may be ruined by
their injudicious use, and obtain a character for fugacity which they in
no way deserve. It requires attention that an excess of dryer renders
oil saponaceous, is inimical to drying, and is otherwise injurious. Some
colours dry badly from not being sufficiently edulcorated or washed.
Sulphate of zinc, as a siccative, is less powerful than acetate of lead,
but is far preferable in a chemical sense. It is supposed erroneously to
set the colours running; which is not positively the case, though it
will not retain those disposed to move, because it wants the property
the acetate of lead possesses, of gelatinizing the mixture of oil and
varnish. These two dryers should not be employed together, since they
counteract and decompose each other, forming two new substances--acetate
of zinc, which is a bad siccative, and sulphate of lead, which is
insoluble and opaque. The inexperienced ought here to be guarded against
the highly improper practice of some artists, who strew their pictures
while wet with acetate of lead, or use that substance in some other
mode, without grinding or solution; which, though it may promote present
drying, will ultimately effloresce on the surface of the work, throw off
the colour in sandy spots, and expose the paintings to peculiar risk
from the damaging influence of impure air.

It is not always that ill drying is to be attributed to the pigments or
vehicles, the states of the weather and atmosphere have great influence
thereon. The direct rays of the sun are powerfully active in rendering
oils and colours siccative, and were probably resorted to before dryers
were--not always wisely--added to oils, particularly in the warm climate
of Italy. The ground may also advance or retard drying, because some
pigments united by mixing or glazing, become either more or less
siccative by their conjunction. Many other accidental circumstances may
likewise affect drying; and among these none is to be more guarded
against by the artist than the presence of soap and alkali, too often
left in the washing of his brushes, and which, besides other bad
results, decompose and are decomposed by acetate of lead and most
siccatives. In such cases desiccation is retarded, streaks and patches
are formed on the painting, and the odium of ill drying falls upon some
unlucky pigment. To free brushes from this disadvantage, they should be
cleansed with linseed oil and turpentine. Dryers should be added to
colours only at the time of using them, because they exercise their
drying property while chemically combining with the oils employed,
during which the latter become thick or fatten. Too much of the
siccative will, as before noticed, often retard drying.

The various affinities of pigments occasion each to have its more or
less appropriate dryer; and it would be a matter of useful experience if
the habits of every colour in this respect were ascertained. It is
probable that siccatives of less power generally than the compounds of
lead and copper might come into use in particular cases, such as the
oxides of manganese, to which umber and the Cappagh browns owe their
drying quality.

To other good attributes of pigments, it would be well if we could in
all cases add the property of being _innoxious_. As this, however,
cannot be, and colours are by no means to be sacrificed on that account,
cleanliness and avoiding the habit of putting the brush unnecessarily to
the mouth, so common in water-painting, are sufficient guards against
any possibly pernicious effects from the use of any pigment. No colour
which is not imbibed by the stomach will in the slightest degree injure
the health of the artist.





PART III.

       *       *       *       *       *

ON COLOURS AND PIGMENTS INDIVIDUALLY.




CHAPTER VI.

ON COLOURS AND PIGMENTS INDIVIDUALLY.


Having briefly discussed the relations and attributes of colours and
pigments generally, we come to their powers and properties
individually--a subject pregnant with materials and of unlimited
connexions, every substance in nature and art possessing colour, the
first quality of pigments.

With regard to _colours_ individually, it is a general law of their
relations, confirmed by nature and the impressions of sense, that those
colours which lie nearest in nature to light have their greatest beauty
in their lightest tints: and that those which tend similarly towards
shade are most beautiful in their greatest depth or fulness, a rule of
course applying to black and white particularly. Thus, the most
beautiful yellow, like white, is that which is lightest and most vivid;
blue is most beautiful when deep and rich; while red is of greatest
beauty when of intermediate depth, or somewhat inclined to light; and
their compounds partake of these relations. We speak here only of the
individual beauty of colours, and not of that relative beauty by which
every tint, hue, and shade of colour become pleasing, or otherwise
according to space, place, and reference; for this latter beauty belongs
to the general nature and harmony of colours.

In respect to _pigments_ individually, it may be observed that--other
things being equal--those pigments are the most beautiful which possess
the most colour, whether they be light or dark, opaque or transparent,
bright or subdued. There are some which exhibit all their colour at a
glance: there are others that the more they are looked into the more
colour they are found to have--containing, as they do, an amount of
_latent colour_, not immediately apparent. Apart from the beauty which a
wealth of colour imparts, those pigments imbued with it are, as a rule,
the most permanent. And not unnaturally so, for the more colour there is
present, the longer it takes to be affected, either by exposure or
impure air. Colour within colour, therefore, not only lends charm to a
pigment, but contributes to its safety.

There is often a vicious predilection of some artists in favour of a
particular colour, from which many of our best colourists have not been
totally free, and which arises from organic defect, or mental
association. Such predilection is greatly to be guarded against by the
colourist, who is every way surrounded by dangers. On the one hand,
there is fear lest he fall into whiteness or chalkiness; on the other,
into blackness or gloom: in front he may run into fire and foxiness, or
he may slide backward into cold and leaden dulness: all of which are
extremes he must avoid. There are also other important prejudices to
which the eye is liable in regard to colours individually, that demand
his particular attention. These are occasioned by the various specific
powers of single colours acting on the eye according to their masses and
the activity of light, or the length of time they are viewed. By
consequence, vision becomes over-stimulated, unequally exhausted, and
endued, even before it is fatigued, with a spectrum which not only
clouds the colour itself, but gives a false brilliancy by contrast to
surrounding hues, so as totally or partially to throw the eye off its
balance, and mislead the judgment. This derangement of the organ may be
caused by a powerful tint on the palette, a mass of drapery, the colour
of a wall, the light of a room, or other accidental circumstance; and
the remedy is to refresh the eye with a new object--of nature, if
possible--or to give it rest. The powers of colours in these respects,
as well as of pigments individually, together with their reciprocal
action and influence chemically, will be adverted to under their
distinct heads.

The attention of the artist to the individual powers of pigments,
although it may be of less concern than the attention to general effect
in colouring, is by no means less necessary in practice. For he who
would excel in colouring must study it from several points of view, in
respect to the whole and the parts of a picture, as regards mind and
body, and concerning itself alone. To this end, is needed a knowledge of
his pigments individually.

If nature has arrayed herself in all the colours of the rainbow, she has
not been niggardly in offering man the materials wherewith to copy them.
The mineral, animal, vegetable kingdom--each helps him to realize,
however faintly, her many manifold beauties: to give some idea, however
slight, of that glorious flood of colour, which light lets loose upon
the world. Metal, ore, earth, stone; root, plant, flower, fruit; beast,
fish, insect--in turn aid the arduous task. The painter's box is a very
museum of curiosities, from every part of the universe. For it, the
mines yield their treasures, as well as the depths of the sea: to it
come Arab camel, and English ox, cuttle-fish and crawling coccus: in it
the Indian indigo lies next the madder of France, and the gaudy
vermilion of China brightens the mummy of Egypt. Varied, indeed, are the
sources whence we derive our pigments; and if they still leave much to
desire, improvement is clearly manifest. Slowly but surely, year by
year, we are advancing. With the growth of science, the exhaustless
stores of creation, will there at last be attained--step by step, though
it be--that summit of the artist's hopes, a perfect palette?




CHAPTER VII.

ON THE NEUTRAL, WHITE.


The term "colour" is equivocal when applied to the neutrals, yet the
artist is bound to consider them as colours; for a thing cannot but be
that of which it is composed, and neutrals are composed of, or
comprehend, all colours.

With regard to colour, then, _white_ in a perfect state should be
neutral in hue, and absolutely opaque; that white being the best which
reflects light most brilliantly. This property in white is called
_body_; by which in other pigments, especially those that are
transparent, is meant _tingeing power_. White, besides its uses as a
colour, is the instrument of light in painting, and compounds when pure
with all colours, without changing their class. Yet it dilutes and cools
all colours except blue, which is specifically cold; and, though it does
not change nor defile any colour, it is changed and defiled by all
colours. This pureness of white, if it be not in some degree broken or
tinged, will cast down or degrade every other colour in a picture, and
itself become harsh and crude. Hence the lowness of tone which has been
thought a necessity in painting, but is such only because our other
colours do not approach to the purity of white. Had we all necessary
colours thus relatively pure as white, colouring in painting might be
carried up to the full brilliancy of nature; and, in fact, more progress
has already been made in that respect, than the prejudice for dulness is
disposed to tolerate.

Locally, white is the most advancing of all colours in a picture, and
produces the effect of throwing others back in different degrees,
according to their specific retiring and advancing powers. These latter,
however, are not absolute qualities of colours, but depend on the
relations of light and shade, which are variously appropriate to all
colours. Hence it is that a white object rightly adapted, appears to
detach, distribute, and put in keeping; as well as to give relief,
decision, distinctness, and distance to every thing around it: hence,
too, the use and requirement of a white or light object, in each
separate group of a composition. White itself is advanced or brought
forward, unless indeed white surround a dark object, in which case they
retire together. In mixture, white communicates these properties to its
tints, and harmonizes in conjunction with, or in opposition to all
colours; but lies nearest in series to yellow, and remotest from blue,
of which, next to black, it is the most thorough contrast. It is
correlative with black, which is the opposite extreme of neutrality.

Perfect white is opaque, and perfect black transparent; hence when added
to black in minute proportion, white gives it solidity; and from a like
small proportion of black combined with white, the latter acquires
locality as a colour, and better preserves its hue in painting. Both
white and black communicate these properties to other colours, in
proportion to their lightness or depth; while they cool each other in
mixture, and equally contrast each other when opposed. These extremes of
the chromatic scale are each in its way most easily denied, as green,
the mean of the scale, is the greatest defiler of all colours. Rubens
regarded white as the nourishment of light, and the poison of shadow.

In a picture, white should not be merely glittering or brilliant, but
tender as well as bright. The eye should seek it for rest, brilliant
though it may be; and feel it as a space of strange heavenly paleness in
the midst of the flushing of the colours. This effect can only be
reached by general depth of middle tint, by the perfect absence of any
white, save where it is needed, and by keeping the white itself subdued
by grey, except at a few points of chief lustre.

White, as a pigment, is of more extensive use than any other colour in
oil painting and fresco, owing to its local quality, its representing
light, and its entering into composition with all colours in the
formation of tints. The old masters have been supposed by some to
possess whites superior to our own, but this may be questioned. The
pureness of whites in some celebrated old pictures is rather to be
attributed to a proper method of using, careful preservation of the
work, and in many instances to the introduction of ultramarine or a
permanent cold colour into the white--such as plumbago--helped also by
judicious contrast.

Notwithstanding white pigments are tolerably numerous, a thoroughly
unexceptionable white is still a desideratum--one combining the perfect
opacity or body of white lead with the perfect permanency of zinc white.
The nearest approach to it that has yet been made, is Chinese white,
which possesses in a great measure the property of the former, and,
being a preparation of zinc, has wholly that of the latter.
Unfortunately Chinese white is a water-colour pigment only, not
retaining its several advantages, stability excepted, when employed in
oil.

1. CONSTANT WHITE,

Also called _Permanent white_, and _Barytic white_, is, when well
prepared, of superior body in water, but has less opacity in oil. It
works in a somewhat unsatisfactory and unpleasant manner, and is
considerably lower in its tone while wet than when dry, a fault which
subjects even an experienced artist to great uncertainty where he uses
it in compound tints. The semi-transparency of the white, while wet,
prevents his judging of the true tint until his colour has dried, when
he frequently finds it harsh and chalky, and out of tone with the rest
of his painting. As little gum as possible should be employed with it,
gum being inimical to its body, or whiteness. The best way of preparing
this pigment, as well as other terrene whites, so as to preserve their
opacity, is to grind them in simple water, and to add towards the end of
the grinding sufficient only of clear _cold_ jelly of gum tragacanth as
will connect them into a body, and attach them to the paper in painting.
Cold starch will answer the same purpose.

Constant white is a sulphate of baryta, found native and known under the
name of heavy-spar, or prepared artificially by adding sulphuric acid,
or a soluble sulphate, to a solution of a barytic salt. In the first
mode, if the white be not well purified from free acid, it is apt to act
injuriously on some pigments. Sulphate of baryta is often used for the
purpose of adulterating white lead, the native salt being ground to fine
powder, and washed with dilute sulphuric acid, by which its colour is
improved, and a little oxide of iron probably dissolved out. Whether
native or artificial, the compound is quite unaffected by impure air,
and is not poisonous.


LEAD WHITES

Comprise and are known under the names of:--_White lead_, _Flake white_
and _Body-white_, _Cremnitz_, or _Kremnitz_, _Crems_ or _Krems white_,
_London_ and _Nottingham white_, _Flemish white_, _Pattison's white_,
_Blanc d'argent_ or _Silver white_, _Ceruse_, _Dutch white_, _French
white_, _Venetian white_, _Hamburgh white_, _Kremser white_, _Sulphate
of lead_, &c.

The heaviest and whitest of these are the best, and in point of colour
and body, are superior to all other whites. When pure and properly
applied in oil and varnish, they are comparatively safe and durable,
drying well without addition; but excess of oil discolours them, and in
water-painting they are changeable even to blackness. Upon all vegetable
lakes, except those of madder, they have a destructive effect; and are
injurious to gamboge, as well as to those almost obsolete pigments, red
and orange leads, king's and patent yellow, massicot, and orpiment. With
ultramarine, however, red and orange vermilions, yellow and orange
chromes, yellow and orange and red cadmiums, aureolin, the ochres,
viridian and other oxides of chromium, Indian red &c., they compound
with little or no injury. Lead colours must not be employed in
water-colour or crayon painting, distemper, or fresco. The whites of
lead are carbonates of that metal, with two exceptions:--Flemish white
or the sulphate, and Pattison's white or the oxychloride. In using all
pigments of which lead is the basis, cleanliness is essential to health.

White lead, by which we must be understood to mean the carbonate, always
contains when commercially prepared a certain proportion of hydrated
oxide. The less of the latter there is present, the better does the
white cover, and the less liable is it to turn brown. The products
formed by precipitation have proved to be inferior in body: otherwise,
pure mono-carbonate of lead-oxide, obtained by mixing solutions of
carbonate of potash and a lead-salt, might be best adapted for a
pigment. However, such a carbonate has been lately produced by Mr.
Spence's process of passing carbonic acid gas into a caustic soda or
potash solution of lead, and for this white an opacity is claimed equal
to that of the ordinary compound.

Great as is the opacity of white lead, it is apt to lose that property
in some measure in course of time, and become more or less transparent.
If, over a series of dry oil-colour rubs of varied hues, there were
brushed sufficient white lead paint to utterly obscure them, after some
years those rubs would indistinctly appear, and by degrees become more
and more visible, until at last their forms--if not their very
colours--could be recognised. From this it would seem that white lead
must slowly but surely part with some of its carbonic acid, and be at
length converted into dicarbonate, a compound possessing less carbonic
acid, and less coating power.

Impure air, or sulphuretted hydrogen, browns or blackens white lead,
converting it partially or wholly into sulphide. It would appear from
the recent investigations of Dr. D. S. Price, that white lead is less
liable to be thus affected, when the pictures in which it is used are
exposed to a strong light; also, that when such pictures have so
suffered, a like exposure will restore them. We have ourselves noticed
the rapidity with which an oil rub of white lead that has been damaged
by foul gas, regains its former whiteness when submitted to air and
sunshine. The action of drying oils has been likewise proved to be very
powerful upon sulphide of lead, an exposure to light for a few days only
being sufficient to change a surface of it, coated with a thin layer of
boiled linseed oil, into a white one. Probably, these agents may have a
similar effect upon other pigments injured by sulphuretted hydrogen, and
many of the colours in paintings may be restored by treating them with
boiled linseed oil, and submitting them to a strong light. That the
result is due to oxidation, there can be no doubt. Indeed, the eminent
French chemist, M. Thénard, was consulted some years back upon the means
of bringing to their original whiteness the black spots which had formed
upon a valuable drawing, by the changing of the white lead, and
employed for that purpose oxygenated water. He had ascertained its power
of converting the black sulphide of lead into the white sulphate, and,
by touching the spots with a brush dipped in the fluid, soon succeeded
in restoring the drawing to its primitive state. Here, again, the use of
the agent might doubtless be extended to other colours, to which foul
air is inimical.

In oil painting white lead is essential in the ground, in dead
colouring, in the formation of tints of all colours, and in scumbling,
either alone or mixed with other pigments. It is also the best local
white, when neutralized with ultramarine or black; and it is the true
representative of light, when warmed with Naples yellow, or orange
vermilion or cadmium, or with a mixture of the yellow and either of the
orange pigments, according to the light.

Ordinary white lead is often mixed with considerable quantities of heavy
spar, gypsum, or chalk. These injure it in body and brightness, dispose
it to dry more slowly, keep its place less firmly, and discolour the oil
with which it is applied, as well as prevent it dissolving completely in
boiling dilute potash-ley, a test by which pure white lead may be known.

The adulteration of pigments, which we have in some instances found
practised to a large extent abroad, is comparatively unfrequent in our
own country, so far at least as regards the superior class of colours
employed by artists. As a rule, such colours when manufactured in
England may be fairly assumed to be genuine; and certainly the
respectable colourmen of the present day are not in the habit of
sophisticating them. We must bear testimony, indeed, to the zeal with
which they purvey, regardless of necessary expense, the choicest and
most perfect materials. This should be a matter of congratulation to the
painter, who must of necessity rely on the faith and honesty of his
colour-dealer; for if he were ever so good a chemist, it would be
impossible for him to analyse each pigment before proceeding to use it.
The fault must rest with himself, therefore, if, through a mistaken
economy, he do not frequent the best houses and pay the best prices. Of
a surety, the colours of the artist are not among those things in which
quality can, or should, be sacrificed to cheapness.

2. BLANC D'ARGENT, OR SILVER WHITE.

These are false appellations of a white lead, called also _French
white_. It is brought from Paris in the form of drops, is exquisitely
white, but of less body than flake white, and has all the properties of
the best white leads. Being subject to the same changes, it is unfit
for general use as a water-colour, though good in oil or varnish.

3. CREMNITZ WHITE,

Known likewise as _Kremnitz_, _Crems_, or _Krems white_, is a carbonate
of lead which derives its names from Kremnitz in Hungary, or Crems or
Krems in Austria. It is also called _Vienna white_, being brought from
Vienna in cakes of a cubical form. Cremnitz white is the brightest white
that is used in oil: it possesses rather less body than flake white,
because the particles are finer. When newly prepared, it gives out a
strong smell of vinegar.

4. FLAKE WHITE,

Called, when levigated, _Body white_, is an English white lead in the
form of scales or plates, sometimes grey on the surface. It takes its
name from its figure, is occasionally equal to Crems white in colour,
and generally surpasses in body all other white leads. In composition,
it is a mixture of protocarbonate and hydrated oxide of lead, the latter
decreasing the opacity of the product according to the greater
proportion in which it is present.

5. FLEMISH WHITE, OR SULPHATE OF LEAD

Is an exceedingly white precipitate from any solution of lead by
sulphuric acid, much resembling the blanc d'argent. It is inferior,
however, both in body and permanence to the ordinary carbonate. Hence,
white lead which has more or less been converted by sulphuretted
hydrogen into sulphide, and again been converted into sulphate by
oxidation, with a view to restoring its colour, becomes peculiarly
liable to the influence of impure air.

6. LONDON AND NOTTINGHAM WHITES.

The best of these do not essentially differ from each other, nor from
the white leads of other manufactories. The latter variety, being
prepared from flake white, is usually the greyer of the two.

7. PATTISON'S WHITE, OR OXYCHLORIDE OF LEAD

Is a mixture of chloride and oxide of lead, formed by precipitating a
solution of chloride of lead with soda, potash, lime, or baryta, in the
caustic or hydrated state. It would appear that when the oxychloride is
used as a paint, the oxide contained in it gives rise to an oleate of
lead, and, in consequence of this saponaceous matter, is capable of
spreading over an extended surface. The product has been described as
possessing properties which are superior to those of white lead,
inasmuch as it does not so readily blacken as the latter body. Dr. Ure,
however, found that water removes the chloride of lead from the paint
compounded of this article, and, consequently, that it is not so
effectual as the carbonate. As an artist's pigment, a partially soluble
compound of lead can decidedly not be eligible.

8. ROMAN WHITE

Is of the purest white colour, and differs only from blanc d'argent in
the warm flesh tint of the external surface of the large square masses
in which it is commonly prepared.

Besides the foregoing, there are other white leads, generally foreign,
cheaper, and adulterated. Many of these are mixed with a small quantity
of charcoal, indigo, or Prussian blue, so that the dead yellowish shade
which they present may be enlivened to a brighter hue. Among them may be
named--

9. CERUSE.

A French variety, not necessarily, but not unfrequently, mixed with
different chalky earths in various proportions; and the following
Belgian kinds:

10. DUTCH WHITE,

Containing three fourths of sulphate of baryta.

11. HAMBURGH WHITE.

A mixture of two parts of heavy spar and one of the plumbous compound.

12. KREMSER WHITE,

Differing from the rest in being unadulterated.

13. VENETIAN WHITE

Composed of heavy spar and the carbonate in equal proportions.


ZINC WHITES.

14. CHINESE WHITE.

The introduction, in 1834, of this peculiar preparation of oxide of zinc
has proved an incalculable boon to water-colour painters, who formerly
had no white which combined perfect permanency with good body in
working. Its invention obviated the necessity for using white lead, a
pigment which, though it may be employed with comparative safety in oil,
is quite unfitted for water. Since the period of its production, Chinese
white has been generally preferred by water-colour artists, as being the
most eligible in their peculiar department. Previous to that period, the
complaints of whites changing were of constant occurrence; but in no
instance has any picture, in which this white has been used, suffered
from its employment. To the colour of oxide of zinc, sulphuretted
hydrogen is altogether harmless; sulphide of zinc being itself white.
The variety under notice works and washes well, possesses no pasty or
clogging properties, and is prepared beautifully white. Moreover, it has
the desirable quality of dense body; so much so, that, as the painter
works, his effects remain unaltered by the drying of the colour. It may
likewise be safely mixed with all other pigments, the following blending
very satisfactorily with the white for opaque lights--cadmium yellow,
orange, and red; gamboge; aureolin; yellow ochre; vermilion; and light
red. Without the artistic drawbacks of constant white or the chemical
defects of white lead, and retaining the advantages of both, Chinese
white cannot but be considered as a most important addition. It is a
matter of regret that this pigment is not equally efficacious in oil.

15. ZINC WHITE

Is either the anhydrous oxide, the hydrate oxide, or hydrated basic
carbonate of zinc. It varies in opacity and colour according to the mode
of manufacture, and the purity of the compound, but may always be relied
upon as permanent. The whiteness of the best samples rivals that of
white lead, and it is not tarnished like the latter by sulphurous
vapours. In opacity it never equals white lead, and might perhaps serve
advantageously as a glaze over that pigment, either alone or compounded
with other colours; as well as act as a medium of interposition between
white lead and those colours which are injured by it, such as gamboge,
crimson lake, &c. When duly and skilfully prepared the colour and body
of this pigment are sufficient to qualify it for a general use upon the
palette in oil: in water it has been superseded by Chinese white.

Occasionally, starch, chalk, white clay, and carbonate of baryta, are
employed as adulterants; none of which, however, are inimical to
stability.

As a pigment, zinc white may be said to be innoxious. As oxide of zinc
does not readily form a saponaceous compound with fats or oil like white
lead, the paint prepared with it and ordinary linseed oil does not dry
or harden so rapidly. For the purpose of causing it to be more
siccative, the oil was boiled with a large quantity of litharge, but by
this method the white was liable to tarnish on meeting with foul air.
Instead of litharge, experiments have led to the choice of salts of
zinc, such as the chloride or sulphate, a small percentage of which, on
being mixed with the oil or oxide, confers upon it the property of
rapidly hardening. The same result is attained by employing an oil,
dried by boiling with about five per cent of peroxide of manganese. In
either case, a paint retaining its white colour permanently is produced.
These agents might, with advantage, be more generally used in the place
of litharge for rendering oils siccative. Many pigments which are not
naturally affected by sulphurous emanations are apt to suffer if mixed
with an oil made drying by means of lead.

       *       *       *       *       *

16. _Cadmium White._

Provided the metal be freed from iron, which we have commonly found to
be more or less present, a white of considerable beauty may be produced;
either directly by precipitation as hydrated oxide or carbonate, or
indirectly by exposing the brown anhydrous oxide to air and light--the
latter mode yielding a product of greater opacity. However prepared,
cadmium white is deficient in body, and apt to assume a yellow tint on
meeting with an impure atmosphere.

17. _Pearl White_

Is an insoluble basic nitrate of bismuth, a pearly white powder of loose
texture, turning grey on exposure, and blackened by sulphuretted
hydrogen. It is chiefly used as a cosmetic, but is said to injure the
skin, rendering it yellow and leather-like; and it has been known to
cause a spasmodic trembling of the face, ending in paralysis.

Another preparation under this name, and now obsolete we believe as a
pigment, was obtained from mother-of-pearl. It is described as
exquisitely white, and of good body in water, but of little force in oil
or varnish.

18. _Tin White_

Resembles zinc white in some respects, but has less body and colour, and
dries badly. According to its composition, it is liable to turn either
black or a dull yellow in contact with sulphurous vapours.

19. _White Chalk_

Is a well-known native carbonate of lime, employed by the artist only as
a crayon, or for tracing his designs, for which purpose it is sawed into
suitable lengths. White crayons and tracing chalks, to be good, must
work and cut free from grit. From this material are prepared whitening
and lime, which form the bases of many cheap pigments and colours, used
in distemper, paper-staining, &c.

Besides those mentioned, there are other metallic whites varying in
beauty and opacity, such as those of mercury, arsenic, and antimony; but
none of them are of any value or reputation in painting, on account of
their great disposition to change of colour, whether by light or foul
air, both in water and oil.

There are also other terrene whites, under equivocal names, among which
are Morat or Modan white, Spanish white, Troys or Troy white, Rouen
white, China white, and Satin white; the latter being a sulphate of lime
and alumina, which dries with a glossy surface. The common oyster-shell
contains a soft white in its thick part, and there is the white of
egg-shells. There is, too, an endless variety of native earths, in
addition to those prepared by art. The whole of them, however, are
destitute of body in oil; and several, owing to their alkaline nature,
are injurious to many colours in water, as well as to all colours which
cannot be employed in fresco.

Among the infinitude of white substances, the artist finds that there
are but three white pigments--those of lead, zinc, and baryta. The first
possesses the greatest opacity, while the second and third are most
durable. The last, however, has so many objectionable qualities, that
the number of eligible whites, may almost be said to be two--lead and
zinc. Of these, the former is blackened by foul air, and in oil, the
latter is wanting in body. In fact, there is but one white pigment which
approaches perfection--Chinese white; and this is only a water-colour.




CHAPTER VIII.

ON THE PRIMARY, YELLOW.


Yellow is the first of the primary or simple colours, nearest in
relation to, and partaking most of the nature of, the neutral white; it
is accordingly a most advancing colour, of great power in reflecting
light. Compounded with the primary _red_, it constitutes the secondary
_orange_, as well as its relatives, scarlet, and other warm colours.

It is the archeus, or prime colour, of the tertiary _citrine_;
characterises in like manner the endless number of semi-neutral colours
called _brown_, and enters largely into the complex hues termed buff,
bay, tawny, tan, dan, dun, drab, chestnut, roan, sorrel, hazel, auburn,
isabela, fawn, feuillemort, &c. Yellow is naturally associated with red
in transient and prismatic colours, and is the principal power with it
in representing the effects of warmth, heat, and fire. Combined with the
primary _blue_, yellow furnishes all the variety of the secondary
_green_, as well as, subordinately, the tertiaries _russet_ and _olive_.
It also enters in a very subdued degree into cool, semi-neutral, and
broken colours, and assists in minor proportion with blue and red in the
composition of _black_.

As a pigment, yellow is a tender delicate colour, easily defiled, when
pure, by other colours. In painting it diminishes the power of the eye
by its action in a strong light, at the same time becoming less distinct
as a colour; while, on the contrary, it assists vision and becomes more
distinct as a colour in a neutral somewhat declining light. These powers
of colours upon vision require the particular attention of the
colourist. To remedy the ill effect arising from the eyes having dwelt
upon a colour, they should be either passed gradually to its opposite
colour, and refreshed amid compound or neutral tints, or washed in the
clear light of day. Hence, in viewing large collections of pictures,
their colours will be more duly estimated by sometimes walking to the
window, or by taking an occasional glance at a millboard, which may be
carried in the hand, painted a cool gray.

In a warm light, yellow becomes totally lost, but is less diminished
than all other colours, except white, by distance. The stronger tones of
any colour subdue its fainter hues in the same proportion as opposite
colours and contrasts exalt them. The contrasting colours of yellow are
a purple inclining to blue when the yellow leans to orange, and a purple
inclining to red when the yellow tends to green, in the mean
proportions of _thirteen_ purple to _three_ yellow, measured in surface
or intensity. Being nearest to the neutral white in the natural scale of
colours, yellow accords with it in conjunction; while, of all colours,
except white, it contrasts black most powerfully. Yellow is discordant
when standing alone with orange, unsupported by other colours.

On account of the paucity of fine yellows among the ancients, we find
that in many paintings and beautiful illuminated MSS. of old, glowing
with vermilion and ultramarine, the place of yellow was supplied by
gilding. Now, certainly, no such scarcity exists; of the three primary
colours, good yellows being the most numerous. It may be observed of
yellow pigments that their colour being primary and therefore simple,
they cannot be composed by any mixture of other colours. The same remark
of course applies to pigments which are red or blue.

20. AUREOLIN.

In these days a new pigment soon finds its level, standing or falling
according to its merits. There are too many colours already on the
palette for a fresh comer to have much chance, unless it possess some
great distinguishing quality, or can take a place which has never been
occupied. Such a void aureolin fills. This "magnificent yellow
pigment," says the _Chemical News_, "supplies a desideratum hitherto in
vain sought for by artists. It is the nearest approach to a perfect
yellow in existence, and more closely resembles the purity of the
prismatic spectrum than any other artificial colour. It is transparent,
has great brilliancy and richness, both pure and in combination, and is
very permanent, being entirely unaffected by exposure to sulphuretted
hydrogen and other atmospheric impurities, or to the direct rays of the
sun during an entire summer. Aureolin, with ultramarine and madder red,
completes the triad of brilliant, permanent, and transparent primitive
colours." The above only tallies with the statements of several
scientific chemists and artists of note, statements which a prolonged
personal experience of the colour enables us to endorse. To our
knowledge, aureolin is quite uninjured by the severest tests to which a
pigment can be subjected. We have found it bear with impunity, even in
its lightest and faintest tints, the foulest gas and the brightest
sunshine. Damp has no effect upon it; and in oil, water, or fresco, it
is equally eligible. With all other colours aureolin mixes safely and
readily, forming combinations of the utmost variety and value. It
affords beautiful transparent tints, well defined, and of exceeding
purity; the paler washes being at once clear and delicate, and admitting
the most subtle gradations of tone. The artistic properties of
aureolin, however, will be best described by quoting the following
extract from Mr. Aaron Penley's _English School of Painting in Water
Colours_:--

    "I have fully tested the qualifications of _Aureolin_ for the
    Landscape Painter, and, without hesitation, pronounce it to be
    the most valuable addition to the 'colour box' since the
    introduction of Rose Madder. It has supplied a deficiency of a
    very important character. Hitherto, no Primitive Yellow has been
    quite satisfactory as to its persistence; so that the Aureolin
    will not only be regarded by the _artist_ as a great boon in the
    production of his works, but it must also be considered as a
    _real_ and _lasting benefit_ to pictorial art in general. The
    permanence and unaltered purity of its lightest and faintest
    tints we are assured may be confidently relied upon, inasmuch as
    they have been fully established by the most severe tests to
    which colour can be subjected, by several of our ablest and most
    talented chemists. It is, therefore, needless to enlarge upon
    its merits, other than that I, for one, feel grateful for its
    introduction. Its uses are manifold, and may be considered
    available for every purpose requiring a Yellow of its character.
    As to Gray--perhaps it is not possible to obtain more delicately
    pure and transparent aërial tints than are to be produced from
    a combination of Cobalt, Rose Madder and Aureolin; all of which
    are of a light description and well suited for the
    representation of soft and thin effects of the atmosphere. These
    colours are each of them beautiful, and yield a most exquisite
    range of tones, which, as they mix together most kindly, render
    them desirable where purity and delicacy are sought. As to
    Foliage.--In speaking of Aureolin as adapted for the colouring
    of foliage and herbage, it is impossible to say too much in its
    praise. It imparts the vividness and freshness of nature to
    every colour with which it is combined--a quality of the highest
    order. As a colour for drapery it has no equal, and may be
    employed with perfect success, either by itself or with any of
    the other pigments.

    "The following table of compound tints will be found extremely
    useful:--

    Aureolin.     | Aureolin.         | Aureolin.    | Aureolin.
    Burnt Sienna. | Vandyke Brown.    | Sepia.       | Sepia, or Rose
    Indigo, or    | Indigo, or French |              |   Madder.
      French Blue.|   Blue.           |              | Cobalt.

    Aureolin.     | Aureolin.         | Aureolin.    | Aureolin.
    Indigo.       | Oxide of Chromium.| Emerald      | Light Red.
                  |                   |   Green.     | Cobalt, or
                  |                   |              |   Indigo.

    Aureolin.     | Aureolin.         | Aureolin.    | Aureolin.
    Burnt Sienna. | Burnt Umber.      | Brown Madder.| Rose Madder.

    "Aureolin, in combination with Cobalt and Sepia, or Rose Madder,
    gives most agreeable and delicate tints for distant trees, when
    under the influence of a soft light, or hazy state of the
    atmosphere. Having most impartially and diligently tested the
    qualities of the Aureolin, I can and do most conscientiously
    recommend its adoption by all who practise water-colour
    painting."

The foregoing sufficiently proves the value of aureolin in water, and
similar flattering notices have been given of the colour in oil. Both in
a chemical and artistic sense, therefore, this new primitive yellow
merits the highest regard, and justly claims a foremost place among that
little band of pigments which are without fear and without reproach.

For mural decoration, aureolin is admirably adapted, but it cannot be
used in enamel, the colour being destroyed by great heat.


CADMIUM YELLOWS.

Of these there are three tints, _Deep_, a so-called _Pale_, and _Lemon_.

21. DEEP CADMIUM.

Cadmium Yellow is comparatively a recent introduction, the metal itself
not having been discovered till 1818. The cadmium yellows of commerce
are (the chromate excepted) all sulphides, and therefore not affected by
impure air. Until lately, they were not manufactured in England but
imported from abroad, and as a rule were sadly doctored. We have found
in them a large proportion of orpiment, chromate of lead, &c., together
with quantities of soluble salt, extracted by boiling water. Owing to
careless preparation, there was also present an unnecessary amount of
dirt, which interfered as much with the purity of the colour, as
sophistication lessened its stability. For these reasons, doubtless,
cadmium yellows got to be regarded by some with disfavour and suspicion;
and it may fairly be said that they did not attain their present
popularity, until they became an article of home produce.

Deep cadmium yellow, if genuine, may without hesitation be declared
permanent, both with respect to foul gas, and exposure to light or air.
The variety under notice is of extreme depth, inclining to orange,
glowing, lustrous, and brilliant. It is not very transparent, but
wonderfully clear and bright, of great power, and the most richly toned
yellow known. For draperies it is particularly adapted, and for gorgeous
sunsets is invaluable. It works and washes well, readily throws all
other yellows into the shade when used alone, and combines admirably
with Chinese white for the light touches of bright clouds or mountains.

By admixture with white, cadmium gives a series of beautiful clear
tints. When compounded with white lead, however, the colour has been
stated to be destroyed. Theoretically, this might very well happen.
Cadmium yellow is composed of cadmium and sulphur--white lead of lead
and carbonic acid. If the former parted with some of its sulphur to the
latter, sulphide of lead would result, which is black. Hence, the partly
decomposed yellow and white would be mixed with black, and there would
be formed a blackish-yellow or a yellowish-black. Again, if the cadmium
parted with the whole of its sulphur to the lead, receiving in exchange
the carbonic acid of the latter, a mixture of black sulphide of lead
with white carbonate of cadmium would be furnished, the result being a
grey. Perhaps the following rough diagram may serve to make our meaning
plainer:--


  Cadmium Yellow {Cadmium.    __________ Carbonate of Cadmium (White.)
                 {Sulphur.             /
                           \          /
                            \        /
                             \      /
                              \    /
                               \  /
                                \/
                                /\
                           ____/__\
  White Lead {Lead.           /          Sulphide of Lead (Black.)
             {Carbonic Acid.

Such is the theory of the reaction which might take place, but which, as
far as our own experience goes, does not. Some deep cadmium yellow which
we ourselves prepared was intimately mixed and ground with an equal
quantity by weight of Cremnitz white, and an oil rub of the compound
laid upon a tile. Having placed the latter on a shelf in the laboratory,
we watched from week to week to see if any approach to blackness
occurred, any diminution in the beauty of the tint; but could perceive
none. Hence, while admitting the possibility of the colour being
damaged or destroyed in the case of an inferior and spurious article, we
conclude that an unadulterated cadmium yellow, containing no free
sulphur, neither injures, nor is injured by, white lead, and may safely
be used therewith. At the same time, the artist should be warned to
satisfy himself of the genuineness of his pigment, or otherwise to
employ the white of zinc, at least as a medium of intervention.

A good sample of cadmium yellow may rather advantageously than otherwise
be compounded with white lead, for we have found that a mixture of equal
parts by weight of the two will bear an atmosphere of sulphuretted
hydrogen that completely blackens the white alone.

With all the sulphides of cadmium a steel palette knife is best avoided.

22. PALE CADMIUM.

The cadmium yellow so-called, is not strictly pale, but pale only when
compared with the preceding. It is, in fact, a full rich colour,
brilliant and permanent, but without that tendency to orange which
distinguishes the deep. For some purposes, when a warm tone is not
required, such a tint is preferable. In water, especially, where
delicacy of colouring can be carried to a greater degree of refinement
than in oil, these differences of hue are important. In the first
medium the faint washes show with a clearness which is not so apparent
in the last, and the most subtle gradation of tone tells with a force in
some measure lost in oil. As a consequence, the colour of the lightest
tints in the distance must be as true as that of the deepest shades in
the foreground, and hence the warmth or coldness of the pale washes of a
pigment should be duly considered.

Pale cadmium yellow with or without aureolin, is adapted for golden
sunsets, and yields with French blue a beautiful sea-green.

24. LEMON CADMIUM.

Very pale cadmium yellows are not permanent, and lemon cadmiums are
decidedly fugitive. Being, like the deep and 'pale' varieties,
sulphides, they are of course unaltered by sulphurous gas; but they will
not stand exposure to light and air, or even to light alone. Some which
were submitted in an air-tight bottle to the action of light gradually
whitened next the glass. Yet they were almost identical in composition
with the deepest and most orange hues, and might have reasonably been
presumed stable. Repeated experiments, however, both with samples of our
own making and of others' manufacture, have shown that for a cadmium to
be durable, it must be of a full, rich, comparatively deep yellow; and
that any paler product than the 'pale' alluded to cannot be depended
on. It is true that a light or lemon tint will fade quicker in water
than in oil, but a colour which is fugitive in the one vehicle cannot be
regarded as eligible in the other. From a somewhat long acquaintance
with cadmiums, we have derived the opinion that their stability rests
much on the mode of preparation, and that an amount of heat is needed
sufficient to make the sulphur _bite into_ the base. This opinion,
indeed, extends to all metallic sulphides, and our belief is, that if
vermilions were made generally by wet processes, they would not be found
the permanent pigments they undoubtedly are.

25. MUTRIE YELLOW.

Under this name a lemon sulphide of cadmium has lately appeared, to
which the foregoing remarks are applicable. A water colour rub on
exposure to air and light faded rapidly, no trace of yellow remaining in
the pale wash. The sample which came under our notice contained a
quantity of free sulphur.

It is to be regretted that these lemon cadmiums are fugacious, so
bright, so clear, are they, and of so pure a lemon tint can they be
obtained. But as no beauty of colour compensates for want of durability,
their place should be supplied by lemon yellow proper, or chromate of
baryta.

26. CHROME YELLOWS,

Also called _Jaune Minérale_, _Jaune de Cologne_ or _Cologne Yellow_,
_Pale Chrome_, and _Deep Chrome_, are chromates of lead, in which the
latter metal more or less exists, according to the paleness or depth of
the colour. Of modern introduction, they are distinguished for their
brilliancy, their opacity and body, and their going cordially into tint
with white, both in water and oil. Owing, however, to a harshness and
hardness of tone for which they are peculiar, a coarse and disagreeable
effect is apt to be produced by their use. In general, they do not
accord with the modest hues of nature, nor harmonize well with the
softer beauty of other colours. Rivalling the cadmiums in brightness,
they are wanting in the mellow richness which belongs to the deeper
varieties of those pigments, as well as in their permanency. Although
they resist the sun's rays for a lengthened period, after some time they
lose their original hue, whether employed alone or in tint, and may even
become black in impure air. Upon several pigments they produce serious
changes, ultimately destroying Prussian and Antwerp blues, when
compounded therewith in the composition of greens, &c. Ranging from
lemon to deep yellow, in oil, provided the atmosphere be good, the
chromes may be found comparatively durable; but, on the whole, the
artist cannot trust to them his reputation as a colourist.

The chromates are often mixed with sulphate of lead, as well as with the
sulphates of baryta and lime. The presence of the first is especially
objectionable, as increasing the tendency of the yellows to be blackened
by foul gas. The sulphates of baryta and lime, however, are sometimes
formed in the process of preparation, in which case they are rather an
advantage than otherwise; inasmuch as they not only lend a softness to
the colour, but decrease the proportion of leaden base, and consequently
the tendency referred to. We may remark, indeed, with respect to
pigments, that it is difficult in many instances to say where
manufacture ends and adulteration begins. A substance may be present
which, although not absolutely essential to the colour itself, has been
legitimately employed to impart a desired quality, or a certain tint.

27. COLOGNE YELLOW

Is a cheap inferior chrome yellow, unfit for artistic purposes, and
consists of twenty-five parts of chromate of lead, fifteen of sulphate
of lead, and sixty of sulphate of lime.

28. JAUNE MINERALE

Is prepared in Paris, and differs in no essential particular from
ordinary chromate of lead, except in the paleness of its colour. The
chrome yellows have also obtained other names from places or persons,
whence they have been brought or by whom they have been made. Another
lead yellow, not a chromate, has likewise been called jaune minérale.

29. CITRON YELLOW

Is chromate of zinc, a bright pale lemon-like yellow, slightly soluble
in water. It is not affected by foul gas, but does not preserve its
colour on exposure to light and air, or even when kept in a book. In
contact with organic substances it is apt to turn green. Compounded,
especially for foliage tints, this yellow is eligible; but if purity of
hue be desired, it should certainly not be employed alone. In this
chromate, as in many others, the affinity of the chromic acid to the
base is small; the former is liable to separate from the latter, and, by
deoxidation, to become converted into green oxide of chromium.

30. GALLSTONE

Is a deep-toned gorgeous yellow, affording richer tints than most other
yellows, but it cannot be depended on for permanency, and therefore is
seldom employed. Its colour is soon changed and destroyed by strong
light, though not subject to alteration by impure air. In oil it is
ineligible. A true gallstone is an animal calculus formed in the
gall-bladder, chiefly of oxen; but the pigment sold under that name is
often replaced by a substitute, resembling the original in colour, but
of greater stability.

31. GAMBOGE,

Sometimes designated _Drop Gum_, and variously written _Gamboge_,
_Camboge_, _Gamboage_, _Cambogia_, _Cambadium_, _Cambogium_,
_Gambodium_, _Gambogium_, &c., is the produce of several kinds of trees.
The natives of the coast of Coromandel call the tree from which it is
principally obtained Gokathu, which grows also in Ceylon and Siam. From
the wounded leaves and young shoots the gamboge is collected in a liquid
state and dried. Our indigenous herb Celandine yields abundantly, in the
same manner, a beautiful yellow juice of the same properties as gamboge.
Gamboge is of a gum-resinous nature and clear yellow colour. It is
bright and transparent, but not of great depth, and in its deepest
touches shines too much and verges upon brown. When properly used, it is
more durable than generally reputed, both in water and oil; and
conduces, when mixed with other colours, to their stability and keeping
their place, on account of its gum and resin. It is deepened in some
degree by ammoniacal and impure air, and somewhat weakened, but not
easily discoloured, by the action of light. Time effects less change on
this colour than on other bright vegetal yellows; but white lead and
other metalline pigments injure, while terrene and alkaline substances
redden it. In water it works remarkably well, and forms an opaque
emulsion without grinding or preparation, by means of its natural gum;
but is with difficulty employed in oil, &c., in a dry condition. It
dries well, however, in its natural state, and lasts in glazing when
deprived of its gum. With regard to other colours it is perfectly
innocent, and though a strong medicine, is not dangerous or deleterious
in use. Gamboge has been employed as a yellow lake, precipitated upon an
aluminous base; but a better way of preparing it is to form a paste of
the colour in water, and mix it with lemon yellow, with which pigment
being diffused it goes readily into oil or varnish. Glazed over other
colours in water, its resin acts as a varnish which protects them; and
under other colours its gum acts as a preparation which admits
varnishing. It is injured by a less degree of heat than most pigments.

In landscape, gamboge affords with indigo or Antwerp blue clear bright
greens, and with sepia a very useful sober tint. For sunrise and sunset
clouds, a mixture of gamboge and cadmium yellow will be found useful.

32. EXTRACT OF GAMBOGE

Is the colouring matter separated from its greenish gum and impurities
by solution in alcohol, filtration and precipitation, by which it
acquires a powdery texture, rendering it miscible in oil, &c., and
capable of being employed in glazing. At the same time it is improved in
colour, and retains its original property of working well in water with
gum. Gamboge is likewise soluble in caustic potash, forming a red
liquid, from which it is thrown down by acids.

33. INDIAN YELLOW

Is a pigment long employed in India under the name _Purree_, but has not
many years been introduced generally into painting in Europe. It is
imported in the form of balls of a fetid odour, and is produced from the
urine of the camel. It appears to be a urio-phosphate of lime, and is of
a beautiful pure yellow colour and light powdery texture; of greater
body and depth than gamboge, but inferior in these respects to
gallstone. Indian yellow resists the sun's rays with singular power in
water painting; yet in ordinary light and air, or even in a book, the
beauty of its colour is not lasting. In oil it is exceedingly fugitive,
both alone and in tint. Owing probably to its alkaline nature, it has an
injurious effect upon cochineal lakes and carmine when used with them.
The colour is not damaged by foul air, and, as lime does not destroy it,
the pigment may be employed in fresco according to its powers.

Indian yellow washes and works extremely well, and is adapted for
draperies and for compounding landscape greens--where permanency is not
required. Blackness in the darkest shadows of the foliage will sometimes
result from too great a use of indigo; should this evil exist, no colour
is so fitted to regain the proper tone as Indian yellow employed
thickly.


LAKES.

There are several pigments of this denomination, varying in colour and
appearance according to the substances used and modes of preparation.
Usually they are in the form of drops, and their colours are in general
bright yellow, very transparent, and not liable to change in an impure
atmosphere--qualities which would render them very valuable, were they
not soon discoloured and even destroyed on exposure to air and light,
both in water and oil. In the latter vehicle, they are bad driers, like
most lakes, and they do not stand the action of white lead and other
metallic pigments. If used, therefore, it should be as simple as
possible. Of these lakes, the following are the best; but it must be
borne in mind that, as not one of them is permanent, the compounds they
afford are of necessity unstable.

34. YELLOW LAKE

Is a bright transparent yellow, a difficult drier, and liable to be
destroyed by light. It affords beautiful foliage tints, and would, if it
could be depended on, be of extreme value in what is called "glazing."

35. ITALIAN PINK,

Also called _English_ and _Dutch Pink_, is an absurd name for a stronger
and richer kind of yellow lake, warmer in tint and more powerful than
the preceding. It is a rich transparent yellow, yielding a variety of
fine foliage tints by admixture with indigo and sepia in different
proportions. These three colours with burnt sienna will produce almost
every variety of sunny foliage. It gives likewise good olive greens with
lamp black.

36. QUERCITRON LAKE,

Or _Quercitron Yellow_, is what its name implies. It is dark in
substance, in grains of a glossy fracture, perfectly transparent, and
when ground is of a beautiful yellow colour. In painting it follows, and
adds richness and depth to, gamboge in water, and goes well into
varnish; but any lead used in rendering oils siccative, browns it, and
for the same reason it is useless in tints.

37. LEMON YELLOW,

Or chromate of baryta, is exceedingly difficult to make well. Upon the
mode of manufacture depend not only the beauty of the colour but its
stability. If properly and carefully prepared, it is of a vivid lemon
tint, deep or pale, very clear, very pure and permanent. It also washes
well, and is entirely free from the slightest tinge of orange. This may
be pronounced the only chromate which possesses durability, not being
liable to change by damp or foul air, by the action of light or the
steel palette-knife, or by mixture with white lead and other pigments,
either in water or oil, in both of which it works pleasantly. Lemon
yellow is chiefly adapted to points of high light, and has a peculiarly
happy effect when glazed over greens in both modes of painting. In water
it exceeds gamboge in brightness, and compounded therewith improves its
beauty. This mixture also goes readily into oil; indeed it is the best
and easiest way of rendering gamboge diffusible as an oil colour--simple
emulsion of the gamboge in a little water, and trituration of the lemon
yellow therewith, being all that is requisite for the purpose.

Lemon yellow has not much power, and is semi-opaque. In distance, its
light wash is used with great effect for cool sunny greens, for which a
minute quantity of emerald green may be added to it. Being uninjured by
lime, the colour is eligible in fresco and crayons.

38. MARS YELLOW,

_Jaune de Mars_, _Jaune de Fer_, _Iron Yellow_, &c., is an artificially
prepared iron ochre, of the nature of sienna earth. In its general
qualities it resembles the ochres, with the same eligibilities and
exceptions, but is more transparent, as well as purer, clearer, richer,
and brighter. Like them it is quite permanent. The colours of iron exist
in endless variety in nature, and are capable of the same variation by
art, from sienna yellow, through orange and red, to a species of purple,
brown, and black, among which are useful and valuable distinctions. They
were formerly introduced by the author, and have been received under the
names of Mars yellow, Mars orange, Mars red, Mars violet, and Mars
brown. All of them are brighter and purer than native ochres, and
equally stable. When carefully prepared, these pigments dry well in
proportion to their depth, are marked by a subdued richness rather than
brilliancy, and have the general habits of sienna earths and ochres.
Their faint washes possess the desirable quality of transparent
clearness.

We have occasionally found Mars yellow mixed with orpiment, or chromate
of lead, for the purpose of brightening the colour.

39. NAPLES YELLOW

Was a compound of lead and antimony, anciently prepared at Naples under
the name of _Giallolino_, and was variously of a pleasing light, warm
yellow tint. It was opaque and of good body, not altered by the light of
the sun, and might be used with comparative safety in oil or varnish,
under the same management as the whites of lead. Like these, however, it
was liable to change even to blackness by damp and impure air when
employed in water. Iron was also destructive of the colour of this
yellow, on which account great care was requisite, in grinding and using
it, not to touch it with the common steel palette knife, but to compound
its tints with a spatula of ivory or horn. For the same reason, it was
apt to suffer in composition with ochres, Prussian and Antwerp blues,
and other pigments of which iron was a principal or ingredient. Used
pure or with white lead it was eligible in oil, in which it worked and
dried well. It was also employed in enamel painting as it vitrified
without change. In this state it was called _Giallolino di fornace_, and
was introduced as a pigment for artists, under the erroneous conception
that vitrification gives permanence to colours, when in truth it only
increases the difficulty of levigation, and injures their texture for
working. We have spoken of Naples yellow in the past tense, because the
pigment now sold as such is generally, or always, a compound colour, or
manufactured with a zinc instead of a lead base. In either case the
preceding remarks are not applicable to the present product, which is
perfectly durable and trustworthy. The new Naples yellow presents an
example of an old objectionable pigment being replaced by a different
and superior preparation. However fugitive certain colours may have
been, the fact of their once having had a place on the palette would
seem to be sufficient recommendation to some. At any rate, they are
still in occasional request, and we cannot but approve the pious fraud
which offers under the same name a good substitute for a bad original.
If an artist must needs demand a worthless pigment, he had better buy a
colour like it that will stand, even if it be not what he asked for.

The tints of Naples yellow are readily and accurately imitated by
admixture of deep cadmium yellow and white.

40. ANTIMONY YELLOW,

As its name denotes, was likewise a preparation of that metal, of a
deeper colour than Naples yellow, but similar in its properties. It was
principally used in enamel and porcelain painting, and differed greatly
in tint. One variety, brighter than the rest, is stated not to have
been affected by foul air, and therefore could not have had a lead
basis.


OCHRES,

Known as _Yellow Ochre_, _Brown Ochre_, _Roman Ochre_, _Transparent Gold
Ochre_, _Oxford Ochre_, _Stone Ochre_, _Di Palito_, &c., are native
earths, consisting chiefly of silica and alumina in combination with
iron, which latter forms the principal colouring matter. They are among
the most ancient of pigments, and their permanency is proved by the
state of the old pictures. In a box of colours found at Pompeii, and
analyzed by Count Chaptal, he discovered yellow ochre purified by
washing, which had preserved its original freshness. They may all be
produced artificially in endless variety as they exist in nature, and
are all converted by burning into reds or reddish-browns. Several ochres
are found in the natural state of so very fine a quality, that they
require no other preparation than that of being washed. Their colours
may be imitated to a certain extent by means of iron alone, uncombined
with silica and alumina; but such ferruginous preparations are not
equally durable, and as their chemical action is stronger, they are more
likely to affect those pigments which are damaged by iron. It often
happens in colours that one component of weak stability, or powerful
for evil, is strengthened and held in check by another; thus in the case
of the ochres, the silica and alumina by keeping a tight hand on the
iron, both ensure its safety, and prevent it injuring others.

41. YELLOW OCHRE,

Called also _Mineral Yellow_, is found in most countries, and abundantly
in our own. It differs much both in constitution and colour, ranging
from a tolerably bright though not vivid yellow to a brown-yellow, and
is generally of a warm cast. Its natural variety is much increased by
artificial dressing and compounding. The best yellow ochres possess no
great force, but as far as they go are valuable pigments, particularly
in fresco and distemper, being neither subject to change by ordinary
light, nor sensibly affected by impure air, or the action of lime. By
time, however, and the direct rays of the sun, they are somewhat
darkened. Like other ochres, they may be safely used in admixture with
pigments which are themselves permanent. With carmine and the cochineal
lakes, or intense blue, the ochres are best not employed.

The impunity with which yellow ochre bears foul gas is one of its many
recommendations. No immediate effect whatever is produced by
sulphuretted hydrogen, and only a slight dirty brown tint is imparted
by its prolonged action. This discolouration a short exposure to air and
light quickly removes. By keeping the ochre sufficiently long in contact
with sulphide of ammonium a jet black is obtainable, but a rub of it in
a moist unwashed state completely regains its yellow hue in a day or so.
Hence, yellow ochre compounded with pigments which suffer from an impure
atmosphere doubtless acts as a preservative agent.

Yellow ochre is usually employed in the distance and middle ground of a
landscape. It possesses a slight degree of turbidness, and is esteemed
for this property, which is considered to give it a retiring quality. By
admixture with Antwerp blue or indigo it affords a fine range of quiet
greens, also a very serviceable yellowish drab with Vandyke brown. The
ochre is valuable in warm skies, the sails of ships and boats, sandstone
rocks and cliffs, buildings, hay, sheep, &c. It does not compound kindly
with any of the cold colours, and should therefore be used as a wash
over others that are dry, when required to qualify their tints.

42. ROMAN OCHRE

Is rather deeper and more powerful than the preceding, as well as more
transparent and cool in tint. In other respects it is similar, and forms
with Antwerp blue and indigo a like excellent range of greens. We may
observe, however, that as indigo is not a permanent pigment, the colours
it yields by admixture cannot be durable as far as the blue is
concerned. Roman ochre and brown madder are admirably adapted for red
sails, and autumnal effects of foliage.

43. BROWN OCHRE,

Likewise known as _Spruce Ochre_ and _Ocre de Rue_, or, more correctly
_Ru_, is a dense, deep-toned brownish yellow, fine in sandy foregrounds.
With Indian yellow it gives a dark autumnal tint of great richness, but
stable only as respects the ochre. When mixed with other colours, it
furnishes a series of rich yet sober tones of extensive use. It covers
well, without being too opaque; and compounded with black and a little
brown-red is good for backgrounds, &c.

44. TRANSPARENT GOLD OCHRE

Resembles in a great degree Roman ochre, but is clearer in its tints,
and more transparent. It is also brighter and much less opaque than
yellow ochre. It approaches somewhat the character of clear bright raw
sienna, though more pure and brilliant, serving for strong
semi-transparent greens and sunny effects.

45. OXFORD OCHRE

Is a native pigment from the neighbourhood of Oxford, semi-opaque, of a
warm yellow colour and soft argillaceous texture, absorbent of water and
oil, in both of which it may be safely employed. It is one of the best
of yellow ochres.

46. STONE OCHRE

Has been confounded with the last variety, to which, as well as to Roman
ochre, it is frequently similar. True stone ochres are found in balls or
globular masses of various sizes in the solid body of stones, lying near
the surface of rocks among the quarries of Gloucestershire and
elsewhere. These balls are smooth and compact, in general free from
grit, and of a powdery fracture. They vary exceedingly in colour, from
yellow to brown, murrey, and gray, but otherwise do not differ from
ordinary ochres.

In enamel they may be used for browns and dull reds.

47. DI PALITO

Is a light yellow ochre, with no special distinguishing quality, except
that its tints are rather purer in colour than most ochres.

48. ORIENT YELLOW

Is an entirely new preparation of absolute permanence, and perfectly
unexceptionable in all respects, both in water and oil. We can give it
no higher praise than by saying it equals aureolin in stability, as well
as in neither injuring, nor being injured by, other colours. Not
possessed of the same amount of transparency, it is distinguished by
greater richness and depth. Of a soft golden hue, lustrous and luminous,
it resembles a brilliant and somewhat opaque Indian yellow. A gorgeous
and durable substitute for that fugitive pigment is produced by
compounding the orient with aureolin, or by using the latter as a glaze.
Being more transparent than cadmiums and less obtrusive, the new yellow
is adapted for mellow sunset and sunrise clouds, or for sunshine on
distant mountains. With French blue it affords a beautiful sea green;
and, mixed with aureolin, gives fine foliage tints. It is also eligible
for draperies and illumination. For enamelling it is inadmissible, the
colour being destroyed by great heat; but in fresco it may safely be
employed.

As in the case of aureolin, we have had a prolonged personal experience
of this new yellow, an experience which justifies us in asserting that
there is none more permanent. In the whole range of artistic colours
there is no pigment less affected by chemical or physical agents. Acid
and ammoniacal fumes, foul gases, and exposure to damp, air, light, or
sunshine, equally fail to injure it. The perfect impunity with which it
bears the action both of sulphuretted hydrogen and sulphide of ammonium
is remarkable. The former gas may be continuously passed into the colour
suspended in water, or a strong solution of the latter sulphide be
poured upon it, and the yellow remains unchanged. Submitted to the
direct rays of the sun during an entire summer, its lightest and
faintest tints have preserved their original hue.

In a preceding chapter we remarked that, provided the colour be stable,
the more colour a pigment possesses the better. The "latent colour"
there alluded to, is one of the advantages of orient yellow. The more it
is looked into, the more colour is seen--there is no suspicion of a base
coloured, the pigment is colour itself.

49. ORPIMENT,

Also called _King's Yellow_, _Chinese Yellow_, _Yellow Orpiment_, &c.,
was known in ancient times: the Romans called it _auri pigmentum_ or
gold colour, whence, by corruption, its present name is derived. It is
found in the native state in China and elsewhere, the best quality being
in masses, consisting of plates of a fine golden hue, intermixed with
portions of a vermilion or orange-red colour; the inferior kinds are
yellow or greenish yellow. Of orpiment, or sulphuret of arsenic, which
is produced artificially, there are two distinct varieties; one of a
bright pure yellow tint, in which the sulphur predominates, and one of
an orange hue, in which the arsenic is in excess. The former is the most
lasting, but it is not durable in water, and still less so in oil,
although not discoloured by impure air. Compounded with white lead it is
soon destroyed, nor can it be mixed with any colours into which lead
enters, such as chrome yellow, the old Naples yellow, &c. The sulphur in
combination with the arsenic, having less affinity for that metal than
for lead, lets it go, and forms a sulphuret of lead of a dark greyish
hue. Moreover, as orpiment is apt to deprive other pigments of their
oxygen, and therefore to change and be changed by all pigments whose
colour depends on that element--metallic pigments especially--it is
probable that the orpiment after some time withdraws the oxygen from the
lead; and this would be an additional cause for the darkening of the
tint composed of the two colours. With sulphides or pigments containing
sulphur, orpiment may be used with less danger. If employed at all,
however, it had better be in a pure and unmixed state. We are far from
recommending orpiment as an eligible colour, and it is highly
poisonous.

Brick dust and yellow ochre are sometimes found as adulterants.

50. RAW SIENNA,

Known likewise as _Raw Sienna Earth_, _Terra di Sienna_, &c., is a
ferruginous native pigment, firm in substance, of a glossy fracture, and
very absorbent. It is of rather an impure yellow colour, and much used
in landscape, being very serviceable both in distance and foreground.
Unless proper skill is exercised in its preparation, the sienna has the
objection of being somewhat pasty in working. Being little liable to
change by the action of either light, time, or impure air, it may safely
be employed according to its powers, in oil, water, and other modes of
practice. It possesses more body and transparency than the ochres; and
by burning becomes deeper, orange-russet, as well as more transparent
and drying.

Raw sienna compounded with cobalt, indigo, or Prussian blue, and a very
little bistre, yields good sea greens, that with indigo being the most
fugitive. Alone, it is adapted for shipping, sails, baskets, decayed
leaves, brooks and running streams.

51. STRONTIAN YELLOW,

To justify its name, should be a chromate of strontia, a compound very
slightly soluble in water, and not more stable than the zinc chromate.
The pigment, however, now sold as strontian yellow is usually formed by
admixture, and contains no strontia whatever. Its absence cannot be
considered a disadvantage, for the substitute possesses a durability to
which the original could lay no claim. Other things being equal, we
prefer an original pigment to one compounded, but a good mixture is
decidedly better than a bad original. A light primrose, clear and
delicate.

       *       *       *       *       *

The foregoing comprise those yellows more generally employed, advisedly
or not, as the case may be. The following are for the most part not
commercially obtainable, a remark that will apply in ensuing chapters to
all numbered colours printed in italics. As a rule, these have become
obsolete as pigments, or have never been introduced as such. The former
could not well be omitted in a work of this kind, and the latter deserve
notice as being at least suggestive. At present, many of them must be
regarded as mere curiosities, being obtainable only from materials of
excessive rarity. In time, however, the sources whence they are derived
may possibly be found in greater abundance, and these now fancy products
prove of value to the palette. The new metal indium, for instance,
furnishes a bright yellow sulphide, like that of cadmium. The colour
could not be affected by foul air, and might possess other advantages
which would render indium yellow a desirable pigment. With regard to
those compounds available for artistic use, but which have not to our
knowledge been adopted, several are quite ineligible. It may be thought
that they are needlessly referred to, but they are mentioned as a
warning and a guide. Strange preparations have been offered as pigments,
and sometimes accepted, witness turbith mineral, iodine yellow, &c. In
these days of chemistry there is less chance for them, but they are
continually submitted to one's notice, their merits being enlarged upon
in proportion to their worthlessness. Through an exceptional ignorance
they may still gain a place, and it has been deemed, therefore, not
superfluous to allude to them. At the same time we do not pretend to
exhaust the list, any more than we claim to note all substances
possessing colour, but yet not admissible as pigments. Some there are
which do not retain that colour on drying; others, whose preparation
involves processes too nice, complicated, or expensive, for
manufacturing purposes. There are many colours, again, which exist only
on paper. We have too often found the imaginations of chemical writers
far more vivid than the colours they describe. Gorgeous yellows turn
out dingy drabs; dazzling scarlets dirty reds; and brilliant blues dusky
slates. As respects colours, most books of science need revising.

52. _Arsenic Yellow_,

Called also _Mineral Yellow_, has improperly been classed as an
orpiment, from which it differs in not being a sulphide, and in
containing lead. It is prepared from arsenic fluxed with litharge, and
reduced to powder. It is much like orpiment in colour, dries better, and
not being affected by lead, is less liable to change in tint. The
presence of the litharge, however, renders it subject to be blackened by
sulphuretted hydrogen. Of course it is poisonous.

53. _Bismuth Yellow_,

Or chromate of bismuth, may be obtained either as a lemon or an orange
yellow, sparingly soluble in water. The colour is not permanent, and
turns greenish-brown even when excluded from light and air.

54. _Copper Yellow_,

Or chromate of copper-potassa, is of a bright yellow tint, not insoluble
in water. It is discoloured both by foul gas and exposure.

55. _Gelbin's Yellow_,

Or chromate of lime, is a pale whitish yellow, poor in colour, partly
soluble, and not at all to be depended on.

56. _Indium Yellow._

Whether the new metal indium will ever be found in sufficient quantity
to render it practically useful remains to be seen. The most abundant
source at present known is the Freiberg blende, 100,000 parts of which
only yield from twenty-five to forty parts of indium. The metal is
chiefly interesting in an artistic sense on account of its sulphide, a
fine bright yellow resembling cadmium, and best obtained by
precipitating an acetic acid solution with sulphuretted hydrogen, or
sulphide of ammonium. In the latter, the yellow dissolves on being
heated, but deposits again on cooling of a rather paler tint. With one
modification, what was said in a former edition of this Treatise
concerning cadmium yellow may be repeated of indium yellow. "The metal
from which it is prepared being hitherto scarce, it has not been
employed as a pigment, and its habits are not therefore ascertained."
All we can tell is, that the colour does not suffer from impure air.

Indium is likewise distinguished by a straw-yellow oxide.

57. _Iodine Yellow_,

Or iodide of lead, is one of those compounds whose presence on the
palette should never have been allowed. Exceedingly brilliant, it is
also utterly fugitive, destroyed by exposure or foul gas, and useless in
admixture. We may state here that, whatever its colour, no pigment
containing iodine can in the slightest degree be relied upon. One of the
most unstable of substances, being slowly volatile even at common
temperatures, iodine is or ought to be quite inadmissible as a
constituent. Combined with lead, which is in itself objectionable, it
forms a yellow possessing every bad quality.

58. _Iron Yellow_,

Or oxalate of protoxide of iron, has very unadvisedly been recommended
as a pigment. It is a bright pale yellow, but soon loses the beauty of
its tint when submitted to air and light, becoming, by peroxidation, red
and buffy. Even in a book the colour changes.

59. _Madder Yellow._

As our (the Editor's) experience of this product is somewhat at variance
with that of the author, we subjoin his original statement. "Madder
yellow is a preparation from the madder-root. The best is of a bright
colour, resembling Indian yellow, but more powerful and transparent,
though hardly equal to it in durability of hue; metallic, terrene, and
alkaline substances acting on and reddening it as they do gamboge: even
alone it has by time a natural tendency to become orange and foxy. We
have produced it of various hues and tints, from an opaque and ochrous
yellow, to a colour the most brilliant, transparent, and deep. Upon the
whole, however, after an experience of many years, we do not consider
them eligible pigments."

While agreeing with Mr. Field as to the character given of these
yellows, we must confess that we have never been able to obtain, nor
have we ever seen, a "most brilliant" madder yellow. Colours bearing
that name have come under our notice, but if their hue was pure and
vivid, they have always proved to be falsely so called, the madder being
conspicuous by its absence. What we have succeeded in producing, and the
genuine samples we have met with, have been fawns, buffs, drabs, &c.,
decidedly "ochrous" yellows, and wanting in stability. It is certain
that no true madder yellow, brilliant and pure, ranks as a pigment at
the present day. A variety known as Cory's Yellow Madder may be briefly
described as Cory's _Brown_ Madder.

60. _Massicot_,

Or _Masticot_, is a protoxide of lead, varying from the purest and most
tender straw colour to a dull orange yellow, and known as Light, Yellow,
and Golden Massicot. It has in painting all the properties of white
lead, from which it may be prepared by gentle calcination in an open
furnace. In tint with that pigment, however, it soon loses its colour
and returns to white, probably extracting some carbonic acid therefrom.
If used in an unmixed state, it is permanent in oil under the same
conditions as white lead, but should not be employed in water, on
account of its changing even to blackness by the action of damp or
impure air. It is an admirable dryer, and has much the same effect as
litharge in rendering oils siccative.

_Litharge_ is merely fused massicot. Old writers speak of litharge of
silver and litharge of gold, oxides of lead, pale and reddish yellow
respectively. Commercial litharge, especially that which is foreign,
contains sometimes a considerable proportion of oxide of copper and
iron. The principal impurity, however, is generally silica, left
undissolved on treating the litharge with nitric or acetic acid.
Litharge is commonly used in preparing drying oils, which contain a
greater or less amount of the oxide in the form of oleate of lead. Oils
made siccative by means of litharge are therefore liable to be damaged
by foul gas. It is a matter of congratulation that such injury is not
lasting, and that the oil, like white lead, recovers its original colour
on exposure to air and light. Some drying oil which we exposed on a tile
to an atmosphere of sulphuretted hydrogen until it was completely
blackened, regained its former yellow hue on being submitted for a day
or so to air and light. Hence, although the employment of lead as a
siccative is not desirable, its effects are not so deleterious as might
be imagined.

61. _Patent Yellow_,

_Turner's Yellow_, _Montpellier Yellow_, _Mineral Yellow_, _Cassel
Yellow_, &c., is a mixture of chloride and oxide of lead, obtainable
either as a pale or a deep yellow. It is a hard, ponderous, sparkling
substance, of a crystalline texture and bright colour; hardly inferior,
when ground, to chrome yellow. Of an excellent body, and working well in
oil and water, but soon injured both by the sun's light and impure air.
A variety, mentioned by Mérimée, in which bismuth and antimony are also
used, is of greater durability.

62. _Platinum Yellow._

Our own opinion of this costly preparation is that the good qualities of
the product do not justify its price. It may be obtained as a bright,
rich, deep yellow, of considerable transparency; but the colour is acted
upon by foul gas and exposure. Even in a book we have found it assume a
dirty greyish cast, and a specimen which had been kept in a drawer,
wrapped up in paper, became perfectly black in a few years. The presence
of palladium interferes with the beauty of the original tint, but does
not affect its stability.

63. _Thallium Yellow._

The new metal thallium yields in combination with chromic acid two
yellow colours, a pale and an orange. They are not absolutely insoluble
in water, and the sulphide of thallium being brown, would probably be
damaged by impure air. But whatever their properties as pigments may be,
their habitudes as such are not yet known. The present scarcity of the
metal renders the colours produced from it mere scientific curiosities.

64. _Thwaites' Yellow._

Under this name chromate of cadmium was introduced some few years back.
If well prepared, it is a fine soft powder of a very vivid light yellow
colour. The compound is too soluble, however, to be of value, its
washings even with cold water being continually tinged yellow. Hence it
turns green after a time, and becomes otherwise discoloured. Like
citron yellow and other chromates apt to assume a green cast, it should
only be employed, if at all, when compounded for foliage tints, &c. This
want of durability is to be regretted, for a good sample of cadmium
chrome is marked by exceeding beauty, unsurpassed for clearness and
purity by any other yellow.

65. _Turbith Mineral_,

Or _Queen's Yellow_, is a subsulphate of mercury, of a beautiful lemon
yellow colour, but so liable to change by the action of light or impure
air, that it cannot be used safely, and hardly deserves attention as a
pigment.

66. _Uranium Yellow_

Can be produced of a pale or orange tint, differing in brightness and
depth of colour according to the mode of preparation. It is fairly
eligible as a pigment, and far superior to the many fugitive compounds
which have from time to time appeared. Being very expensive, however,
and not possessing the good qualities of its compeers lately introduced,
uranium yellow has but little chance of being employed now.

67. _Yellow Carmine_

Is a rich transparent colour, somewhat resembling an ochre compounded
with Indian yellow. On exposure to light, it behaves much as a mixture
of those pigments would do, the rich _yellowness_ entirely disappearing,
and the sober-coloured earth being left behind.

       *       *       *       *       *

From several metals besides those mentioned, yellows more or less vivid
and durable may be obtained--from tin, nickel, cerium, molybdenum, &c.;
but we do not know that any one of them would be a really desirable
addition. To justify its being brought out, a new pigment should own
some special advantage, chemical or artistic, by which it may be
distinguished from other colours. No purpose would be answered by
crowding the palette with mere repetitions, even though they were
stable. If, for instance, indium yellow were found exactly similar to
that of cadmium, in colour, opacity, permanence, its presence would be
quite superfluous. The mistake is often made of offering a fresh
compound for a pigment when something as good or better, and cheaper may
be, already exists. We remember a patient experimenter, who had produced
a pink from cobalt, wondering why his colour should be so generally
declined. The product was not wanting in either beauty or stability, but
he forgot that the lakes of madder were far more beautiful, at least as
durable, and much less expensive. We have said that we do not join in
the cry of there being too many pigments, or share the opinion that
there is not room for more, but we do enforce the necessity of progress.
Let us have as many good colours as possible, but let the new be
superior to the old, and all be distinct from each other.

As far as yellows are concerned, the palette possesses both variety and
durability. Opaque or transparent, bright or subdued, deep or pale, it
presents a sufficiency of permanent pigments. Most noteworthy are
aureolin, the deep and 'pale' cadmiums, lemon yellow, Mars yellow, the
modern Naples yellow, the ochres, orient yellow, and raw sienna. Whether
used alone or in tint these are, if genuine, perfectly reliable, and
comprise the list of those durable colours which may be called pigments
of the first class.

Among pigments of the second class, or the semi-stable, gamboge holds
the foremost place, for although not strictly durable in itself, it
conduces to the permanence of other colours. Chrome yellows, citron
yellow, strontian yellow, and Thwaites' yellow, also belong to this
division.

As third class pigments, or the fugitive, must be ranked Mutrie yellow
and other lemon cadmiums, the true gallstone, Indian yellow, the lakes,
orpiment, Gelbin's yellow, massicot, patent yellow, and turbith mineral.

It must not be forgotten, however, that these three classes are subject
to modification. A durable pigment may be so adulterated as to descend
to the second or even the third division, while a semi-stable or
fugitive colour may be replaced by a permanent or comparatively
permanent substitute, as in the case of strontian yellow and gallstone.
It should likewise be remembered that pigments are apt to vary in
stability according to the mode of their preparation; and that, as there
are different degrees of permanence, there are different degrees of
fugacity.




CHAPTER IX.

ON THE PRIMARY, RED.


Red is the second and intermediate of the primary colours, standing
between _yellow_ and _blue_; and is also in like intermediate relation
to _white_ and _black_, or light and shade. Hence red is pre-eminent
among colours, as well as the most positive of all, forming with yellow
the secondary _orange_ and its near relatives, scarlet, &c.; and with
blue, the secondary _purple_ and its allies, crimson, &c. It gives some
degree of warmth to all colours, especially to those which partake of
yellow.

Red is the archeus, or principal colour in the tertiary _russet_; enters
subordinately into the two other tertiaries, _citrine_ and _olive_; goes
largely into the composition of the various hues and shades of the
semi-neutral _marrone_ or chocolate, and its relations, puce, murrey,
morelle, mordore, pompadour, &c.; and is more or less present in
_browns_, _grays_, and all broken colours. It is likewise the second
power in harmonizing and contrasting other colours, as well as in
compounding _black_ and all other neutrals, into which it enters in the
proportion of five,--to blue, eight,--and yellow, three.

Red is a colour of double power in this respect too; that, in union or
connexion with yellow, it becomes hot and _advancing_; but mixed or
combined with blue, cool and _retiring_. It is, however, more congenial
with yellow than with blue, and thence partakes more of the character of
the former in its effects of warmth, the influence of light and
distance, and action on the eye, by which the power of vision is
diminished on viewing this colour in a strong light. On the other hand,
red appears to deepen in colour rapidly in a declining light as night
comes on, or in shade. These qualities of red give it great importance,
render it difficult of management, and require it to be generally kept
subordinate in painting. It is therefore rarely used unbroken, as the
ruling or predominating colour, or for toning a picture; on which
account it will always seem detached or insulated, unless repeated and
subordinated. Hence Nature is sparing with her red, employing it with as
much reserve in the decoration of her works as she is profuse in
lavishing green upon them. This latter is of all colours the most
soothing to the eye, and the true contrasting or harmonizing equivalent
of red, in the proportional quantity of eleven to five, according to
surface or intensity: being, when the red inclines to scarlet or orange,
a _blue_-green; and when it tends to crimson or purple, a
_yellow_-green.

Red breaks and diffuses with white with peculiar loveliness. It is
discordant when standing with orange only, requiring to be joined or
accompanied by their proper contrast, to resolve or harmonize the
dissonance. In landscapes, &c., abounding with hues allied to green, a
red object properly placed as regards light, shade, or distance,
conduces wonderfully to the life, beauty, harmony, and connexion of the
colouring. Red is, indeed, the chief element of beauty in floral nature,
the prime ornament of the green garb of the vegetal kingdom.

Being the most _positive_ of colours, and holding the middle station of
the primaries, red contrasts and harmonizes with black and white, which
are the _negative_ powers or neutrals of colours, and the extremes of
the scale. Moreover, as red is less nearly allied to black or shade than
to white or light, this harmony is most remarkable in the union or
opposition of white and red, and this contrast most powerful in black
and red.

As a primary and simple colour, red cannot be composed by mixture of
other colours. So much is it the instrument of beauty in nature and art
in flesh, flowers, &c., that good pigments of this genus are most
indispensable. On the whole, the palette cannot be considered so well
furnished with reds as with yellows. Especially is there wanting a
permanent transparent scarlet, a colour for which a prize of £500 has
for many years been offered by the Society of Arts.

68. CADMIUM RED.

The deep, pale, and lemon yellows which cadmium at first afforded, were
followed by an orange, which has quite recently been succeeded by a red.
This is a most vivid orange-scarlet, the red predominating, of exceeding
depth, and intense fire. It is a simple original pigment, containing no
base but cadmium, and possessing a large amount of latent colour. It is
more orange in hue than vermilion, and has the advantages of flowing and
drying well, of greater brilliancy, of retaining that brilliancy when
dry, and of considerable transparency. Hence this red is preferably
employed where opacity is to be avoided--in sunset clouds for instance.
As day declines or by artificial light, the colour approaches very
nearly to a deep pure scarlet; and the best substitute for a permanent
transparent scarlet which has yet been obtained is furnished by
admixture of cadmium red with madder carmine, or by using the latter as
a glaze. Compounded with white, the red yields a series of fine flesh
tints; and it mixes readily and safely with other colours. Without
harshness or rankness, neither injured by an impure atmosphere nor
exposure to light and air, cadmium red is eligible in every department
of art, enamel painting only excepted. In illumination, the red
contrasted by viridian will be found most beautiful and effective.
Seeing that previous to its introduction the number of bright reds, not
being crimson, nor of a crimson cast, was limited to vermilions, pure
scarlet, red chrome, and red lead, of which the first alone were
permanent, there was room on the palette for a strictly durable and
somewhat transparent pigment like cadmium red, with its many distinctive
properties.


COCHINEAL LAKES.

Lake, a term derived from the _lac_ or _lacca_ of India, is the name of
a number of transparent red and other coloured pigments of great beauty,
prepared for the most part by precipitating coloured tinctures of dyeing
drugs upon aluminous bases. Consequently, the lakes form a numerous
class, both with respect to the variety of their appellations, and the
substances whence they are produced. Those under notice are known as
_Carmine_, _Crimson Lake_, _Scarlet Lake_, _Purple Lake_, _Chinese
Lake_, _Florentine Lake_, _Hamburgh Lake_, _Roman Lake_, _Venetian
Lake_, &c., and are obtained from the "coccus cacti," an insect found on
a species of cactus, from the juice of which it extracts its
nourishment. This coccus is a native of Mexico, where two kinds are
recognised, under names which signify wild cochineal and fine cochineal.
The latter may be considered a cultivated product, its food and wants
being carefully attended to, while the former is left in a natural
state, and is less valuable. Wild cochineal is distinguished by having a
woolly downy coat, which is not the case with the fine cochineal. The
females, of which there are from one hundred and fifty to two hundred
for each male, are marked by the absence of wings, and constitute the
commercial article. They are generally killed by immersion in boiling
water, which causes them to swell to twice their natural size, and are
then dried and packed for market. The insects shrivel in drying, and
assume the form of irregular grains, fluted and concave. The best sorts
have a silvery-grey colour, with a purplish reflection, and seem to be
dusted with a white powder. This appearance is often given by means of
heavy spar, carbonate of lead, Venice talc, &c. A good lens, however,
will mostly expose the fraud; or it may be detected by macerating the
insect in water, and allowing the loosened pulverised particles to
settle.

Cochineal is a very rich colouring substance, yielding about half its
weight of real colouring matter, which may be easily extracted by
boiling in water. Dr. Warren De La Rue, who examined the living animal,
states that on piercing the side of the insect a purplish-red fluid
exuded, containing the colouring matter in minute granules. This
colouring matter he succeeded in obtaining pure, in the form of a
purple-brown friable mass, pulverizable to a fine red powder,
transparent when viewed by the microscope, and soluble both in water and
alcohol in all proportions. At temperatures above 136° it decomposed,
and by alkalies its colour was turned to purple. These facts account for
the care required in drying cochineal lakes, and for their liability to
change of hue when in contact with alkaline substances, as in mural
decoration.

The lakes of cochineal may be known from those of the dye-woods by their
solubility in ammonia, a liquid which purples but does not dissolve the
colours produced from the latter.

69. CARMINE.

A name once given only to the fine feculences of kermes and cochineal
tinctures, now denotes generally any pigment which resembles them in
beauty, richness of hue, and powdery texture. We have, therefore, blue
and other coloured carmines, though the term is usually confined to the
crimson and scarlet lakes of cochineal. As at present commonly
understood, carmine is that preparation of cochineal which contains the
most colouring matter and the least aluminous base. Hence it is the
richest, deepest, most intense, and most permanent. Although not to be
classed as durable, yet by reason of its extreme depth, carmine is more
stable than the weaker crimson, scarlet, and purple lakes. When
well-made, pure, and employed alone and in body, it has been known to
retain its colour for years, especially if protected by oil or varnish.
In tint with white lead, however, it has no stability; and though little
affected by impure air, in glazing it is soon discoloured and destroyed
by the action of light. Of great power in its full touches, it possesses
considerable clearness in the pale washes, and works admirably. In
landscape, carmine is seldom used, the colour being chiefly valued in
flower painting and illumination.

It has been erroneously stated that the finest carmines cannot be made
in England, owing to a want of clearness in the atmosphere and a
scarcity of sunshine. For many years, however, they have been produced
in this country, not only finer than any foreign preparations, but
equally good in winter as in summer.

Carmine is sometimes sophisticated with starch, vermilion, and with
alumina not formed in the process of manufacture. Occasionally also, a
portion of the animal matter of the cochineal from which it has been
obtained is left mixed with it. These accidental or intentional
impurities may mostly be detected by heating the carmine with liquid
ammonia, which entirely dissolves the colouring matter and leaves the
impurities in an insoluble state.

70. CRIMSON LAKE

Is a cochineal pigment containing more aluminous base than carmine, and
is consequently weaker in colour and less stable. Deficient in much of
the depth and brilliancy which belong to the latter, it is more commonly
employed and more generally useful. This lake is of service in mixing
tints, to impart richness, in flower painting and illumination, and is,
like all cochineal colours, of greater utility in water than in oil.
With cobalt and gamboge it yields an excellent gray, and with cobalt
alone a fine purple for heather. Distant hills may be strengthened with
a tint of French blue and lake, and Vandyke brown with the crimson will
be found admirable for a rich coloured foreground. Many other beautiful
tints, unexceptionable in an artistic sense, are afforded by crimson
lake on admixture. It should be remembered, however, that not one of
them is permanent as far as the lake is concerned. All cochineal
pigments are more or less affected by strong light, which weakens their
tints, and in time deprives them of colour; and it is not by being
compounded that a fugitive colour is rendered durable.

71. SCARLET LAKE

Is prepared in the form of drops from cochineal, and is of a fine
transparent red colour and excellent body, though, like other lakes, it
dries slowly. Discoloured and destroyed by strong light both in water
and oil, and not permanent in tint with white lead or in combination
with other pigments, it possesses the common attributes of cochineal
lakes. Yet when well prepared, used in sufficient body, and not unduly
exposed, it has been found to last a lengthened period; but it ought
never to be employed in glazing, nor at all in works that aim at high
reputation and stability. It is in general tinted with vermilion, which
has probably been mixed with lakes at all times to give their scarlet
hue and add to their weight; for upon examining with a powerful lens
some fine pictures of ancient masters, in which lake had been used in
glazing, particles of vermilion were apparent, from which lake had
evidently flown. Unfortunately, these lakes are injured by vermilion as
they are by lead, so that glazings of cochineal over vermilion or lead
are particularly apt to vanish. This effect is very remarkable in
several pictures of Cuyp, where he has introduced a figure in red from
which the shadows have disappeared, owing to their having been formed
with lake over vermilion. The scarlet hue of this lake should properly
be imparted to it during the process of manufacture, and not by
subsequent mechanical admixture.

72. PURPLE LAKE

Is a species of crimson lake with a purple cast, transparent and
deep-toned, and useful in shadows: in other respects resembling that
pigment. Red being its predominant colour, we have preferred classing
this so-called purple among the reds, in spite of its name. On the whole
it is more durable than crimson lake.

73. FLORENTINE LAKE

Differs from scarlet lake only in the mode of preparation. Formerly the
lake so called was extracted from the shreds of scarlet cloth. The same
may be said of _Chinese Lake_.

74. HAMBURGH LAKE

Is a lake of great power and depth of colour, purplish or inclining to
crimson, which dries with extreme difficulty, but differs in no other
essential respect from preceding cochineal lakes--an observation which
applies to _Roman Lake_, _Venetian Lake_, and many others; none of
which, however beautiful or reputed, is entitled to the character of
stability either in hue, shade, or tint.

75. DRAGON'S BLOOD

Is a resin brought from the East Indies. It is of a warm
semi-transparent, rather dull red colour, which is deepened by impure
air, and darkened by light. There are two or three sorts, but that in
drops is the best. White lead soon destroys it, and in oil it dries with
extreme difficulty. It is sometimes used to colour varnishes and
lackers, being soluble in oils and alcohol. Although it has been
recommended as a pigment, dragon's blood does not merit the attention of
the artist.

76. INDIAN LAKE,

Likewise called _Lac Lake_. This is obtained from the lac or lacca of
India, a resinous secretion which seems to depend upon the puncture of a
small insect--_coccus ficus_--made for the sake of depositing its ova on
the branches of several plants, found in Siam, Assam, and Bengal. The
twigs soon become encrusted with a mammelated substance of a red colour
more or less deep, nearly transparent, hard, and having a brilliant
conchoidal fracture. The roughly-prepared coating is imported in two
forms, called lac-lake and lac-dye, which contain about 50 per cent of
colouring matter, combined with more or less resin, and with earthy
matters, consisting chiefly of carbonate and sulphate of lime and
silica.

Indian lake is rich, transparent, and deep,--less brilliant and more
durable than the colours of cochineal, but inferior in both respects to
those of madder. Used thickly or in strong glazing, as a shadow colour,
it is of great body and much permanence; but in thin glazing it changes
and flies, as it also does in tint with white lead. In the properties of
drying, &c., it resembles other lakes. The pigment may be dispensed with
in favour of madder lake and madder brown, whose combinations serve for
every purpose to which it can be applied, and are stable.

Lac appears to be the lake which has stood best in old pictures, and was
probably employed by the Venetians, who had the trade of India when
painting flourished at Venice.


MADDER LAKES.

_Rubric Lakes_, or _Field's Lakes_, are derived from the root of "rubia
tinctorum," a plant largely grown in France and Holland, whence the bulk
of that used in England is obtained. The French madders are in a state
of very fine powder, containing one half their weight of gum, sugar,
salts, and other soluble substances, which water speedily dissolves.
Madder roots in the unground state are imported from the Levant, and
called Turkey roots. Good qualities of Turkey madder yield near sixty
per cent of extractive matters, a term that includes everything
removable by water and dilute alkalis: the woody fibre is therefore
about forty per cent. This is presuming the root to be genuine, for
madder is often adulterated with brickdust, red ochre, red sand, clay,
mahogany sawdust, logwood, sandal and japan-wood, and bran.

Unlike cochineal, madder possesses several colouring matters; the
question of which, despite the learned researches of Dr. Schunck and
others, is far from settled yet. The following remarks embody our own
experience of the root, simply as a pigment-producing product:--

Madder contains five colouring matters--yellow, red, orange, purple, and
brown. Of these, the first colour is soluble in cold water. By washing
the powdered root quickly with it by decantation, the yellow and brown
are extracted in the form of an opaque liquid. If this be decanted and
allowed to stand, the brown deposits, leaving a clear buffish-yellow
supernatant liquor. In the root from which the extract was poured, the
remaining three colours are left. On adding a strong boiling solution of
alum, these are dissolved, yielding a fine red liquid. From this there
can be thrown down, by the agency of different chemicals, a red, an
orange, or a purple precipitate. Or, supposing the whole of the
colouring matter to be deposited as a red lake, it is possible to
convert this--also by the agency of different chemicals--either into
orange or purple. Hence, for all practical purposes, madder contains but
three colouring matters: a yellow, soluble in cold water; a brown, not
soluble in, but capable of being extracted by cold water; and a red,
soluble in boiling alum, and furnishing at will a purple or an orange.

As was observed in the previous chapter, no good pigment is obtained
from the yellow, of which the less there is present the better; but the
brown affords a valued product, which will be duly noticed. It is
essential to the purity of the reds, that the madder should be freed
from both these colours; and it was probably due to insufficient aqueous
washing of the root, that the old lakes were dull and muddy, mere
brick-reds of ochrous hues. For many years, however, lakes have been
prepared perfectly transparent, and literally as beautiful and pure in
colour as the rose; qualities in which they are unrivalled by the lakes
and carmine of cochineal. They have justly been considered as supplying
a desideratum, and as among the most valuable acquisitions of the
palette in modern times, since permanent transparent red and rose
pigments were previously unknown. The red varieties range from rich
crimson to a delicate rose, and are known as _Madder Carmine_, _Field's
Carmine_, _Pink Madder_, _Rose Madder_, _Madder Lake_, and _Liquid
Rubiate_ or _Liquid Madder Lake_.

77. MADDER CARMINE,

Or _Field's Carmine_, like that of cochineal, is the richest and deepest
lake prepared, containing most colouring matter and least base. It
differs from the paler products chiefly in transparency and intensity,
and is the only durable carmine for painting either in water or oil; for
both which it is qualified by texture without previous grinding. In
common with the other reds of madder, its faint washes possess greater
clearness than those of cochineal. This carmine is a difficult colour to
make well, exceeding care and nicety being required to obtain the
fullest tint: hence it is apt to vary in hue according to the skill of
the manufacturer. Being expensive also, the price increasing according
to depth of colour, the lake has been the most liable to adulteration,
of all the reds of madder. Mérimée states that samples were sent to him
from Berlin, under the name of "carmine madder," which evidently owed
their brightness to tincture of cochineal. It is certain that madder
lakes have been imitated on the Continent with various success by those
of lac, cochineal, and carthamus or safflower. The best we have seen is
the _laque de garance_, which was tinged with the rouge of carthamus,
and was of course inferior in durability. As, however, liquid ammonia
and alkalis generally dissolve the colours of cochineal, lac, and
safflower, the test is simple. If the liquid remain uncoloured on
adding ammonia to an assumed madder lake, in all probability the pigment
is genuine.

78. ROSE MADDER.

The exquisite flowers of Bartholomew, Miss Mutrie, and others, give
evidence of the beauty, purity, and stability of the reds of madder,
both in water and oil. This variety, less intense than the preceding and
without its carmine hue, is of a rich rose colour--a true rose--tending
neither to crimson, scarlet, nor purple. Marked by a peculiar softness,
and an unusual clearness in its pale washes, rose madder affords the
most perfect carnation tints known. Not liable to change by the action
of light, impure air, or admixture with white lead and other colours, it
resembles all madder lakes in these respects. Like them, too, it is but
a tardy dryer in oil unless thoroughly edulcorated, and does not work in
water with the entire fulness and facility of cochineal pigments. When,
therefore, permanence is of no consideration, the latter may still be
preferred. In those works, however, where the hues and tints of nature
are to be imitated with stability and pure effect, the rose colours of
madder are become indispensable. They have this advantage, moreover,
that they possess the property of ultramarine of improving in hue by
time--their tendency being to their own specific prismatic red colour.
As they are too beautiful and require saddening for the general use of
the painter, the addition of manganese brown, cappagh brown, or burnt
umber, adds to their powers, and improves their drying in oils; for
which last purpose a little japanner's gold size may be likewise
employed.

In the light touches of bright clouds or mountains, where a mixture of
cadmium yellow and Chinese white is used, rose madder is invaluable for
glazing over such touches when dry, should they be required of a warmer
hue. The red portion of sunset skies may be improved by a thin wash of
this pigment, tinged perhaps with the above yellow, or with gamboge.
Most serviceable landscape tints are afforded by admixture of rose
madder with cobalt, Indian red, purple madder, yellow ochre, lamp black,
&c. In painting flesh, the lake cannot be dispensed with.

79. PINK MADDER

Was a weaker preparation of the preceding, paler in hue and possessing
less colour. It was formerly employed in miniature painting, but with
the decline of that art became less and less used, until it may now be
said to be obsolete. The name, however, still lives, but is applied to
rose madder, which is indeed indifferently called _Rose Madder_, _Pink
Madder_, or _Madder Lake_. Speaking of pink roses, Mrs. Duffield remarks
that "the local colour is best imitated with pink madder," and the
Messrs. Rowbotham observe "this heather may be best represented by
cobalt and madder lake." In trade catalogues several names are often
given, as in this instance, to one and the same pigment. The seeming
superfluity is rendered necessary through some artists knowing a pigment
by one name and some by another. Hence arises the value of a list of
synonyms.

80. LIQUID RUBIATE,

_Rose Rubiate_, or _Liquid Madder Lake_, is a concentrated tincture of
madder of the most beautiful and perfect rose colour and transparency.
It is used as a water colour only in its simple state, diluted with
water, and with or without gum. In oil it dries by acting as a
siccative. Mixed or ground with all other madder colours, with or
without gum, it forms combinations which work freely in water, and
produce the most charming and stable effects. The rubiate also furnishes
a fine red ink, and is a durable stain for printing on cotton, &c. To
the tinting of maps and charts permanently, it is peculiarly suited.

81. MARS RED

Or _Rouge de Mars_, is an artificial iron ochre, similar in subdued tint
and permanence to the native earths. Its chemical affinities, however,
are greater than those of the latter, and it therefore requires to be
employed cautiously with pigments affected by iron. In this respect the
red resembles its compeers, Mars yellow, Mars orange, Mars violet, and
Mars brown, all of which are iron ochres artificially prepared.
Possessing the richness and depth of Indian red, it is distinguished by
the russet-orange hue of light red. Its pale washes are marked by
considerable clearness. In keeping the Mars colours separate from the
ochres, we have followed the plan of the author.


OCHRES

Comprise _Red Ochre_, _Indian Red_, _Light Red_, _Venetian Red_,
_English Red_, _Persian Red_, _Prussian Red_, _Spanish Red_, _Brown
Red_, _Indian Ochre_, _Scarlet Ochre_, _Carnagione_, _Terra Puzzoli_,
_English Vermilion_, _Spanish Brown_, _Majolica_, _Redding_, _Ruddle_,
_Bole_, _Almagra_, _Sil Atticum_, _Terra Sinopica_, &c. They are rather
hues and tints than definite colours, or more properly belong to the
tertiary, semi-neutral, and broken colours. As a rule they are native
pigments, found in most countries, and very abundantly and fine in our
own; but some are products of manufacture, and obtainable in the variety
of nature by art.

The colouring matter of these earths is the red oxide of iron, as that
of the yellow ochres is the yellow oxide. All the yellow ochres are more
or less reddened by being burnt, as yellow oxide of iron itself becomes
red on calcination. It was observed in the fourth chapter that time has
often the effect of fire, more or less intense; and hence it is that
yellow ochres occasionally assume a buffish-red hue, by the gradual
peroxidation of the iron. Similarly, if a yellow ochre be but partially
calcined, the red so obtained is apt to deepen or darken. Especially do
these changes take place when the iron oxides are not associated with an
earthy base; when, in fact, the so-called ochres cannot be classed as
such. In this case, too, as was lately remarked, the pigments are more
chemically active, and more likely to affect those colours to which iron
is inimical.

82. RED OCHRE

Is a native earth; sometimes brown ochre burnt, and called _Brown Red_.
It is less pure in hue and clear in its tints than light red, and is
best reserved for dark and vigorous shades and touches. For draperies of
a dusky red it is well suited, or even for the shadows of bright-red
drapery. In dead colouring it is very valuable. Like all ochres, it is
characterized by permanence in water, oil, crayons, and fresco; and is,
like most of them, available in enamel-painting.

Almagra, the Sil Atticum of the ancients, is a deep red ochre found in
Andalusia; as is also their Terra Sinopica or Armenian Bole, dug
originally in Cappadocia, and now found in New Jersey and elsewhere
under the name of Bloodstone.

83. INDIAN RED,

Once known as _Persian Red_, is brought from Bengal. It is a natural
earth rich in peroxide of iron, of a purple russet hue and good body,
and valued when fine for the clearness and soft lakey tone of its tints.
In a crude state it is a coarse powder, full of extremely hard and
brilliant particles of a dark appearance and sometimes magnetic. It is
greatly improved by grinding and washing over, and is very permanent.
Neither light, impure air, mixture with other colours, time, nor fire,
effects any sensible change in it; but being opaque and not keeping its
place well, it is unsuited for glazing. This pigment differs
considerably in its hues, that which is most rosy being esteemed the
best, and affording the purest tints. Inferior ochres were formerly
substituted for Indian red, which procured it a variable character; but
the colour being now obtained abundantly can in general be had genuine.
It is a good drier.

Mixed with Indian ink, it furnishes useful shadows; and compounded with
cobalt or indigo, most serviceable grays. For sunsets, where deep purple
lines are louring over the horizon's brink, a mixture of French blue
with a little Indian red and lake is admirably adapted. In twilight and
stormy clouds, in sails and buildings, in shade carnations of portraits
and backgrounds, &c., the red is often employed.

84. LIGHT RED

Is an ochre of an orange-russet hue, chiefly valued for its tints. The
principal yellow ochres afford this colour best, and the brighter and
clearer the yellow ochre is from which it is prepared, the brighter will
the red be, and the better flesh tints will it yield with white. Light
red has the good properties common to ochres, dries capitally, and
furnishes an excellent crayon. It is much used both in figure and
landscape painting, giving fine grays with cobalt, and serviceable
compounds with yellow ochre, indigo, lamp black, rose madder, Payne's
grey, brown madder, &c.

Terra Puzzoli, a volcanic production, is a species of light red, as is
the Carnagione of the Italians.

85. VENETIAN RED,

Less known as _English Red_, _Prussian Red_, and _Scarlet Ochre_. True
Venetian red, that is, the red of the Venetians, was probably brought
from India, and similar to our modern Indian red. The Venetian red of
the present day, however, is an artificial product, containing no earthy
base, and therefore improperly classed among the ochres. It is prepared
by calcining sulphate of iron, to which a little nitre may be
advantageously added. The result is a peroxide of iron, resembling light
red, but more powerful, and of a more scarlet hue. It is very permanent,
but being a purely iron pigment, should be cautiously employed with
colours affected by that metal. Though not bright, its tints are clear,
and it mixes and works kindly with cobalt or French blue, affording fine
pearly grays. Heightened by madder lake, it furnishes a glowing red,
very useful in some descriptions of skies; and saddened by black, it
gives low toned reds of good quality for buildings. With white it
produces carnation tints nearly approaching to nature, and much employed
by Titian, Vandyke, and others. Compounded with aureolin, Venetian red
yields a clear orange of considerable transparency.

_Spanish Red_ is an ochre differing little from the above.

86. PURE SCARLET,

Or _Iodine Scarlet_, is an iodide of mercury, having the body and
opacity of vermilion, and being as much inferior to it in permanence as
it is superior in brilliancy. Of all artistic pigments, it is at once
the most dazzling and the most fugitive, and should have no place on the
palette. If used, it should be with an ivory knife, as iron and most
metals change it to colours varying from yellow to black; hence it
should never be compounded with metallic pigments. So sensitive, indeed,
is it to the slightest touch of metal, that it has been known to turn to
a dull brown merely by being washed over with a colour which had been
taken out of its saucer with a penknife. In the cake, it must be
carefully kept wrapped up in paper, otherwise the presence of metal
tubes or a knife in the colour-box may spoil it. By a foul atmosphere,
the scarlet is soon utterly destroyed, and even metallized. In contact
with the air, it quickly fades away; and has been found to vanish
completely, when exposed to light alone. Employed in water, a thick
glaze of gum-arabic or gamboge adds to its stability. As a landscape
pigment, the colour is out of the general scale of nature; but in
flower-painting its charms are almost irresistible. Nothing certainly
can approach it as a colour for scarlet geraniums, but its beauty is
almost as fleeting as the flowers.

87. RED CHROME,

Also called _Scarlet Chrome_, is a bright chromate of lead of an
orange-red colour, the red being predominant. Rank in tone, it is liable
to the changes of the yellow chromes, though in a less degree. The
recent introduction of cadmium red renders the use of this unnecessary.

88. RED LEAD,

_Minium_, or _Saturnine Red_, is an ancient pigment, by some old writers
confounded with cinnabar, and termed Sinoper or Synoper. It is an oxide
of uncertain composition, prepared by subjecting massicot to the heat of
a furnace with an expanded surface and free accession of air. Of a
scarlet colour and fine hue, it is warmer than common vermilion, whose
body and opacity it possesses, and with which it was once customary to
mix it. Bright, but not so vivid as the iodide of mercury, it is more
durable, although far less so than vermilion. When pure and alone, light
does not affect its colour, which soon flies, however, on being mixed
with white lead or any preparation of that metal. By impure air, red
lead is blackened and ultimately metallized.

On account of its extreme fugacity when compounded with white lead, this
red cannot be used in tints; but employed, unmixed with other pigments,
in simple varnish or oil not rendered drying by any metallic oxide, it
may stand a long time under favourable circumstances. It is an excellent
dryer in oil, and has often been used as a siccative with other colours,
but it cannot safely be so employed except with the ochres, earths, and
blacks in general. Oils, varnishes, and, in some measure, strong
mucilages, are preventive of chemical action in the compounding of
colours, by intervening and clothing the particles of pigments; and
hence heterogeneous and injudicious tints and mixtures have sometimes
stood well, but are not to be relied upon in practice. Altogether, red
lead is a dangerous pigment in any but skilled hands, and has naturally
had a variable character for permanence. It is frequently adulterated
with earthy substances, such as brickdust, red ochre, and colcotha.


VERMILIONS.

Vermilion is so called from the Italian word _vermiglio_ (little worm,)
given to the kermes or "coccus ilicis," which was used as a scarlet dye
before the introduction of cochineal. It is a sulphuret of mercury,
which previous to levigation is called Cinnabar; and is found native in
quicksilver mines, as well as produced artificially. This is an ancient
pigment, the [Greek: kinnabari] of the Greeks, and the _minium_--a term
now confined to red lead--of older writers. Pliny states that it was so
esteemed by the Romans, as to have its price fixed by express law of
state. Among other places, the natural product is met with in
California, Spain, and Peru; and in China there is a native cinnabar so
pure as only to require grinding to become very perfect vermilion.
Whether the natural possesses any advantages over the artificial,
appears to admit of doubt: Bouvier thought that the former blackened
more than the latter, and others coincide with him. As, however, native
vermilion has become commercially obsolete, the question of their
comparative permanence is of little importance. Theoretically, it is
difficult to assign a reason why there should be any difference between
the two.

Vermilion is capable of being made by both wet and dry processes, but
the last are almost exclusively adopted on a scale, and are, we
believe, preferable. Our opinion, expressed with some diffidence, is,
that pigments whose colour depends on the union of sulphur with a
metal--such as vermilion and cadmium yellow--are more stable when the
sulphur is forced to bite into the base. This can only be effected by a
considerable degree of heat, far greater than can be obtained in any
moist method. We hold that in pigments so produced, the sulphur is less
liable to oxidation by air and light, and that therefore the colour
better withstands exposure to those agents. Before now, vermilions have
been taxed with fading in a strong light: supposing them genuine, it
would be interesting to know by what mode they were manufactured.

There are two kinds of vermilion in common use, European and Chinese, of
which the first inclines to orange and the second to purple. These
include the several varieties known as--_Vermilion_, _Deep Vermilion_,
_Pale Vermilion_, _Scarlet Vermilion_, _Chinese Vermilion_, _Carmine
Vermilion_, _Extract of Vermilion_, _Orange Vermilion_, and _Field's
Orange Vermilion_.

89. VERMILION,

Deep or pale, when well made and pure is of strict permanence, not
sensibly affected by light, time, or foul air; and eligible either in
water, oil, or fresco. For an enamel colour it is unsuited, being
dissipated at a red heat, a test that detects the presence of any
non-volatile adulterant. The best vermilion is a powerful vivid colour,
higher in tone than all reds, except the scarlet iodide of mercury. With
this it should not be compounded, but with other pigments it may safely
be used in admixture, as far as its own colour is concerned. Of great
body, weight, and opacity, it is a somewhat slow drier; and does not
retain that brilliancy when dry, which is peculiar to it while wet. A
want of transparency, and not drying well, prevent its being so
generally employed as would be desirable. Pictures should seem to be
painted with colour, not with pigment, the material being lost amid the
hues, tints, and shades; but with such compounds as vermilion, the art
of concealing art becomes difficult indeed. The pigment is apt to
predominate over the colour, and the painting to look mechanical rather
than natural: particles are apparent where hues alone should be seen,
and all sense of reality is destroyed. For these reasons, vermilion is a
dangerous pigment in unskilled hands, needing an intimate acquaintance
with its physical properties. The extreme weight or specific gravity of
the red renders it liable to sink and separate when compounded with
other colours; hence the heavier those mixed with it the better. Its
almost equal opacity, too, and habit of washing up, militate against its
use by young painters. With experience, however, and due care, this is
a serviceable colour; yielding with white most delicate flesh tints, and
in minute proportion with cobalt or French blue and white, tender aërial
grays.

Being cheaper than formerly, vermilion is not so much adulterated as it
once was; although, even now, brickdust, orpiment, &c. sometimes
sophisticate it. The knavish practices to which the pigment has been
subjected, have acquired it an ill-fame both with authors and artists.
Vermilion has been charged with fading in the light, and with being
blackened by impure air; but it was the custom to crimson the colour by
means of lake, or tone it to a scarlet hue by red lead. With pigments as
with persons, evil communications corrupt good manners--a motto that
might be written with advantage on every palette.

90. SCARLET VERMILION

Resembles the preceding in all respects, except in being more scarlet in
its tint, and washing better; advantages which render it more useful
when the tone is required to be very bright and pure. At one time, the
Dutch alone in Europe possessed the secret of giving to vermilion a rich
scarlet colour.

91. CHINESE VERMILION,

Or _Carmine Vermilion_, partakes of a crimson hue, and is adapted,
mixed with white, for the rose and lilac-tints of some complexions. Like
other vermilions, however, the colour needs much nicety of management;
and it must not be attempted to further enrich it by admixture of
cochineal lakes. Those colours, as we have remarked, cannot safely be
brought into contact with vermilion, either compounded or as a glaze.
The reds of madder should be substituted for them.

92. EXTRACT OF VERMILION,

A somewhat curious name for a metallic colour, was a peculiar
preparation of the author, possessing in its time certain advantages
over other vermilions, and especially distinguished by a more scarlet
hue. Now, however, extract of vermilion and scarlet vermilion are
synonymous terms.

93. ORANGE VERMILION

Is rather more transparent than ordinary vermilion, with a clear but not
bright orange hue. It also washes better, and is for landscape purposes
more generally useful. Resembling red-lead in appearance, it is not
subject to its changes, being perfectly durable in oil and water. A most
powerful tinger of white, its tints are warmer than red-lead's,
affording delicate carnations similar to those of Titian and Rubens.
This pigment--or, preferably, the succeeding variety--may be employed
with excellent results in scumbling of flesh, for which Sir Joshua
Reynolds improperly used the so-called red orpiment. It dries in simple
linseed oil, but works with best effect in water with a considerable
portion of gum. In speaking of sunset and sunrise clouds, Mr. Penley
observes--"Orange vermilion if used so thin as to get rid of its
opacity, is a fine tone; but it must be remembered that _transparency_
is the character of the sunset or sunrise, and hence arises the
difficulty of employing such opaque colour effectively." Before the
introduction of cadmium red, this and the following pigment were the
best and only unexceptionable orange-reds known. It is probable,
however, that the new colour will in a great measure supersede these
latter in cases where transparency is sought. Orange vermilion is often
a mixture, in which case the yellow employed is apt to separate from the
red and float on its surface.

94. FIELD'S ORANGE VERMILION

Is a superior preparation to the preceding, being brighter, purer, and
clearer. It possesses also, less opacity, and is not a compound. Both
pigments are rather reds with an orange cast than strictly orange
colours, and are therefore inserted in this chapter.

       *       *       *       *       *

95. _Antimony Red_,

Or Mineral Kermes. We have obtained this colour ranging from light
orange to deep carmine, of different degrees of brightness and
stability. Some of the tints stood well in a book, but faded on exposure
to light and air; and some even vanished when secluded from those
agents. It has more than once been recommended as a pigment, but our
experience is against its adoption by artists. The colour is not
affected by sulphuretted hydrogen.

96. _Chica Red_

Is extracted from the leaves of a tree growing in central and southern
America. A sample examined by Mr. O'Neill was in small irregular lumps,
of a bright scarlet colour, adherent to the tongue like indigo, and
taking a metallic polish of a greenish reflection, when rubbed against a
hard smooth body, as the finger nail. So far it seems to be only
employed by the Indians as a paint for their bodies, mixed up with fatty
matters. It has doubtless been used in painting: for in the old churches
of those parts of America there is a good deal of red colour, which
remains brilliant and sound after a couple of centuries; and from the
appearance of it, and such accounts as can be collected, it is probably
this chica. A portion was forwarded to an eminent artist in England, to
ascertain whether it would be of any value as a pigment in the fine
arts. His report is stated to have been unfavourable; and the chica,
contained in a gourd labelled "Chica d'Andiguez," was then tested as to
its capabilities for dyeing and printing. Fine and durable reds were
found to be produced by it upon woollen, equal to those of cochineal. To
mordanted calico the shades imparted were dull and heavy, but very
solid. Chica is described as a very strong colouring matter, a small
quantity dyeing a large amount of cloth, and as more nearly resembling
lac lake than anything else.

No information existing as to its price, or the quantity that could be
obtained if it were wanted, chica remains in the state of an unapplied
product. If it really possess, however, the durability assigned to it,
this red is worth attention. With regard to the artist's disapproval,
the chica sent him may not have been properly or sufficiently prepared
to adapt it for a pigment.

97. _Coal-Tar Colours._

Our work might be considered incomplete without some allusion to the
coal-tar colours, even though they are rather dyes than pigments, not
possessing sufficient stability for the palette. To avoid repeated
reference, we have preferred grouping them in this chapter, irrespective
of hue. Consequently, yellow, red, blue, orange, green, purple, brown,
and black, will be all comprised under the heading of coal-tar colours.

Previous to the year 1856 the colouring matters derived from coal-tar
were practically unknown. Until then, that black evil-smelling substance
was looked upon as almost worthless; but gradually the unsightly grub
emerged into a beautiful butterfly, clothed first in mauve and next in
magenta. After its long winter of neglect, there sprung from coal-tar
the most vivid and varied hues, like flowers from the earth at spring.
At a touch of the fairy wand of science, the waste land became a garden
of tropic tints, and colour succeeded colour, until the whole gamut had
been gone through. Never was transformation more dazzling or more
complete. The once despised refuse was now a valued commercial
product--indeed a trade in itself. Perfectly fascinated by the study,
chemists threw themselves heart and soul into coal-tar, and coal-tar
colours were to be seen everywhere.

It were beside our purpose to enter into the various stages through
which coal has to pass to become colour. Enough to state that to the
introduction of gas-light we are indebted for the acquisition of
coal-tar colours, the starting point for the production of mauve,
magenta, &c., being the manufacture of coal-gas. From the destructive
distillation of coal, coal-tar oil results; and from this are obtained
the products which yield the colours in question. Among these products
may be mentioned aniline, rosaniline, napthaline, chinoline, carbolic
acid, picric acid, &c., with their derivatives.

Of the fifty-one compounds furnished by the distillation of coal,
perhaps the most popularly associated with coal-tar colours is aniline,
to which we will therefore confine ourselves. Discovered in 1826, this
body was formerly prepared from indigo--in Spanish, _anil_, whence the
name; but is now produced on a larger scale from benzol, a coal-tar
product. As the source of mauve and magenta, aniline must be considered
the parent of coal-tar colours generally. Little was known of it at one
time except that on being mixed with a solution of chloride of lime
there was formed a splendid purple liquid, which immediately gave place
to a dingy reddish precipitate. From the investigation of this simple
fact, however, by Mr. W. Perkin, there was created a new and important
branch of chemical industry--the manufacture of coal-tar colours. The
violet mauve led the way, followed by the red magenta, the blue azuline,
the yellow phosphine, the green emeraldine, the orange aurine, by
purple, and brown, and black. Such were the hues, with many intermediate
tints and shades, which one reaction brought forth. The world rubbed its
eyes with astonishment; and truly it seemed almost as wonderful to
produce the colours of the rainbow from a lump of coal, as to extract
sunshine from cucumbers.

The history of these colours reads more like a romance than a sober
story, but to the artist it is of slight practical interest.
Sufficiently stable as dyes, though they be, coal-tar colours are not
adapted to the palette. Mauve, magenta, with a few others, hare been
introduced as pigments and fairly tried, but a want of permanence has
been fatal to their success. Mauve is more durable than magenta, and the
rest vary in stability, but none of them have proved really fitted for
artists' colours. Exposed to light and air, they all more or less fade,
especially in thin washes; and they have mostly the objection of
staining and permeating the paper or canvas on which they are employed.
Used in body, some may be found eligible in portfolio illuminations and
the like, where the brilliancy of their colours shows to advantage; but
in landscapes and pictures of life, coal-tar pigments are best avoided.

Cakes of red, blue, violet, and other hues, may be prepared for
painting, by combining the colours with a mixture of starch and alumina,
or with soap and alumina in a moist state--thus: 150 parts of white curd
soap, dissolved in 1000 parts of hot water, are mixed with an alcoholic
or a methylated spirit solution of six parts of the crystallized or
solid coal-tar colour. To this are added 250 parts by weight of washed
gelatinous alumina. The whole is then well stirred, collected on a
filter, drained, and dried. Several hues, tints, and shades may be
obtained by compounding: for instance, an orange is produced on
admixture of picric yellow with aniline red, or a green by adding the
same yellow to aniline blue.

98. _Cobalt Reds._

There are obtainable from cobalt by different processes rose and red
colours of more or less beauty and intensity, but all vastly inferior to
those of madder, in whose absence alone they could gain a place on the
palette. Durable as a rule, they are in general characterized by a fatal
chalkiness, and poorness of hue. More expensive than the madder colours,
and without their purity, delicacy, depth, or transparency, cobalt reds
have often been offered as pigments, and as often declined. A colour may
be good in itself, but if there is something better and at the same time
cheaper, its introduction into commerce is out of the question.

99. _Copper Reds._

A somewhat finely coloured red oxide is produced by exposing to a white
heat for twenty minutes, a mixture of certain proportions of blue
vitriol, mono-carbonate of soda, and copper filings. The product,
however, is affected by impure air, and is otherwise not so desirable as
an iron oxide.

An interesting account has lately been given by Professor Church of a
new animal pigment, containing copper, found in the feathers of the
violet plantain-eater and two species of Turacus, natives respectively
of the Gold Coast, the Cape, and Natal. _Turacine_, the name proposed
for it, is noticed here only because it is the first animal or vegetable
pigment, with copper as an essential element, which has been hitherto
isolated. The colour is extracted by solution in an alkali, and
precipitation by an acid, and is changed on long exposure to air and
moisture to a green hue. As the entire plumage of a bird yields not more
than three grains of pigment, turacine must be looked upon as a mere
curiosity.

100. _Ferrate of Baryta_,

Produced by adding aqueous ferrate of potash to an excess of dilute
solutions of baryta salts, has been described as carmine-coloured and
permanent. We have not found it to be so--an experience which has
evidently not been confined to ourselves; and we cannot help thinking
that this is one of those errors which get copied from one chemical work
into another, to the special confusion of students. It is but fair,
however, to add that in Mr. Watts' Dictionary of Chemistry, the latest
and best work of the kind, this ferrate is said to become "brick-red
after washing and drying at 100° C.," and to be only "tolerably stable."

101. _Gold Reds._

Many organic substances added to gold solutions throw down either the
metallic gold or the red oxide, which then unites with the organic
compound more or less decomposed and forms a red precipitate. Sugar,
gum, the decoctions of cochineal, gamboge, fustic, turmeric, sumach,
catechu, and Brazil wood, all afford red pulverulent colours. Boiled
with sugar, gold solution gives first a light and then a dark red.
Whatever their merits, the excessive costliness of these preparations
renders them inadmissible as pigments. At one time, indeed, a gold
compound known as purple of Cassius was so employed, but this soon
became obsolete on the introduction of madder purple.

102. _Iodine Pink._

There may be obtained from iodine and mercury a very pretty pink colour,
analogous in composition to pure scarlet. It is apt to pass into the
scarlet modification, and is in other respects even less to be depended
on than that variety.

103. _Kermes Lake_

Is an ancient pigment, perhaps the earliest of the European lakes, and
so called from the Arabic Alkermes. It is sometimes spelt _cermes_,
whence probably cermosin and crimson, and kermine and carmine. In old
books it is named vermilion, in allusion to the insect, or _vermes_,
from which it is prepared. This insect is the "coccus ilicis," which
feeds upon the leaves of the prickly oak in the south of Europe. Like
the "coccus cacti," it is covered with a whitish dust, and yields a
tinctorial matter soluble in water and alcohol. Kermes and the lac of
India doubtless afforded the lakes of the Venetians, and appear to have
been used by the earliest painters in oil of the school of Van Eyck. The
former, under the appellation [Greek: kurno kokino], is said to be
employed by the modern Greeks for dyeing their caps red.

Some old specimens of this pigment which the author obtained were in
drops of a powdery texture and crimson colour, warmer than cochineal
lakes, and having less body and brilliancy. They worked well, however,
and withstood the action of light better than the latter, though the sun
ultimately discoloured and destroyed them. In other respects, they
resembled the lakes of cochineal. As a colouring matter, kermes is only
about one-twelfth part as powerful as that substance.

104. _Lawson's Red._

In 1861 it was stated that Professor Lawson had prepared a new dye of
great richness, in the laboratory of Queen's College, Canada, from an
insect, a species of coccus, found the previous summer for the first
time on a tree of the common black spruce (_Abies nigra_), in the
neighbourhood of Kingston. Having been but recently observed, a
sufficient quantity had not been obtained for a complete series of
experiments as to its nature and uses; but the habits of the insect, as
well as the properties of the dye, seemed to indicate that it might
become of practical importance. In colour it closely resembled ordinary
cochineal, but was rather more scarlet in hue. It was described as
capable of being produced in temperate countries. The colouring matter
had not then been thrown upon a base, nor do we know that it has since
been introduced as a pigment. If it possessed greater stability than
cochineal, with equal brilliancy and depth, this dye might form one of
those colours of the future, to whose possible sources we would direct
attention.

105. _Manganese Red._

Bisulphide of arsenic combines with basic metallic sulphides forming a
class of sulphur-salts, called by Berzelius, hyposulpharsenites. The
hyposulpharsenite of manganese is a dark red precipitate, uninjured by
sulphuretted hydrogen, and so far applicable as a pigment. Containing
arsenic, it would of course be poisonous; and would probably be found to
fade on exposure to air and light.

106. _Murexide._

The red obtained from this substance created a great deal of interest
among printers and dyers on its introduction in 1857, or thereabouts.
For purity and brilliancy of shade it was not excelled by any other
colour, but not being able to stand the effects of air and light, its
employment was limited. We are not aware that murexide has yet been
brought forward as a pigment, and judging from its character as a dye,
it would scarcely enrich the palette. Dyes and pigments have much in
common, and a fugitive dye cannot be expected to furnish a permanent
pigment.

Murexide is produced by the action of ammonia on alloxan, which is
itself derived from the uric acid of guano by treatment with nitric
acid, and was known nearly forty years back to stain the fingers and
nails red. The first murexide sent into the market was a reddish-purple
powder, dissolving in water with a fine purple tint, leaving a little
residue undissolved. Owing to improvements in manufacture, it is now
capable of being prepared almost chemically pure, and with that green
metallic reflection peculiar to several coal-tar salts and the wings of
certain insects. When sulphuretted hydrogen is passed through a
concentrated solution of murexide, it is immediately decoloured; a fact
which renders it likely that murexide pigments would be as liable to
suffer from an impure atmosphere, as from exposure to light and air.

When an alkaline solution of murexide is precipitated by an acid, a
light shining powder results, called purpuric acid. This dissolves in
alkalies, and combines with metalline bases to form various coloured
compounds, termed _Purpurates_. Among them may be mentioned a red
purpurate of lead, a purple-red and a rose-coloured purpurate of
mercury, a purple-red purpurate of silver, a dark red-brown purpurate of
strontia, a crystalline red purpurate of cobalt, a scarlet purpurate of
platinum, a yellow purpurate of zinc, and a green purpurate of baryta.
All of these, however, being more or less soluble in water, and owing
their colours to murexide, would be ill adapted for pigments.

107. _Paille de Mil,_

Or African Cochineal, is a substance obtained from Africa. Whether it
has received its name of cochineal from its appearance or origin is not
clear, but it behaves more like galls and sumac than cochineal, though
it does give a kind of red with alumina mordants. The colours it yields
are deficient in brightness, and it has otherwise been reported
unfavourably of.

108. _Peganum Harmala,_

The seeds of which afford a red colour, has been investigated by the
French, but described as inferior to existing reds both in brilliancy
and stability.

109. _Persulphomolybdates._

The metallic compounds formed by the combination of persulphomolybdic
acid with a base are pulverulent, in many cases of a red colour, and for
the most part insoluble in water. With barium, the acid furnishes a
yellowish-red powder, insoluble in, but made denser by water, which
imparts to it a cinnabar colour. With calcium it is said to yield a
scarlet, sparingly soluble in water. With chromium, uranium, lead,
platinum, and copper, it gives a dark red; that from the last metal
turning brown when collected on a filter. It likewise produces reds with
zinc, cadmium, iron, mercury, and tin; of which the last is slightly
soluble in water.

Molybdenum being a rare metal, and persulphomolybdate of potash, the
salt used in the foregoing reactions, difficult to prepare, it is
unlikely that the colours named will rank among the pigments of this
generation. Nevertheless, as we have observed before, such fancy
products should not be altogether ignored, it being quite as well to
have some knowledge of our resources, even though those resources be not
at present available. All the rare metals afford coloured compounds:
tantalum, niobium, pelopium, vanadium, tellurium, titanium, yttrium,
lanthanum, didymium, glucinum, cerium, thorinum, zirconium, palladium,
rhodium, iridium, ruthenium, osmium, indium, thallium, &c.; and it is
just possible that some of these may one day scrape acquaintance with
the palette.

110. _Red Chalk_,

The colouring matter of which is sesquioxide of iron, is used as a
crayon. Some specimens are excessively hard, so much so that they are
difficult to crush, even in an iron mortar; while others have the
consistence of the softest iron-ochres. They vary too in tint from a
fawn colour to the softest brick-red, occasionally being almost as
bright as a mixture of equal weights of vermilion and Venetian red. The
amount of iron oxide present has been found to range from four to
thirty-seven per cent, according to the depth and hardness of the
samples. When a specimen of red chalk tolerably rich, but not too rich,
in iron oxide is finely powdered and strongly ignited, it offers a
remarkable change of colour, becoming a dull sage-green. Perhaps this,
if it were permanent, might prove useful in foliage tints.

111. _Red Precipitate_,

Or mercuric oxide, may be obtained either of a brick-red or
orange-yellow colour. It is destroyed by impure air, and on exposure to
sunshine gradually turns black, being superficially decomposed into
oxygen and metallic mercury or mercurous oxide.

112. _Rose Pink_

Is a coarse kind of lake, produced by dyeing chalk or whitening with
decoction of Brazil wood, peachwood, sapan, bar, camwood, &c. It is a
pigment much used by paper-stainers, and in the commonest distemper
painting, &c., but is too perishable to merit the attention of the
artist.

Chevreul obtained a crystalline substance from Brazil wood, which he
looked upon as the pure colouring matter, or as containing the pure
colouring matter, and which gave red and crimson precipitates with many
salts. Possibly some of these might prove more durable than the roughly
made rose pink.

113. _Rouge_,

The rouge végétale of the French, is a species of carmine, prepared
from safflower or carthamus, which is the flower of a plant growing in
the north of Africa, India, and other warm climates. Safflower yields
two colours--a valueless yellow which dissolves in cold water, and about
five per cent of red, insoluble in water but dissolved by alkalies. The
red, or carthamin, furnishes a pigment of exquisite beauty, marked by
richness, transparency, and free working. Its extreme fugacity, however,
militates against its employment by artists. As a dye, its manner of
fixing upon fibre is different from that of any other colouring matter;
requiring no mordant, like madder or cochineal, and needing no solution,
like indigo or anotta, but fixing at once as soon as the cloth is
brought into contact with it. But even for a dye the colour is fugitive,
fading after a few hours' exposure to sunshine, and sometimes being
quite bleached in the course of a day. It is when combined with
levigated talc to form the paint of the toilette that the red becomes
most serviceable. Possessing a peculiar softness and velvety glow, rouge
is an unrivalled--and a most harmless--aid to beauty.

_Chinese Rouge_ and _Pink Saucers_ have much of the qualities of, and
appear to be also prepared from, the safflower.

114. _Rufigallic Red._

When a duly proportioned mixture of gallic acid and oil of vitriol is
carefully and gradually heated to 140°, a viscid wine-red liquid
results. If this be poured into cold water, after cooling, a heavy
brown-red granular precipitate is formed, soluble in 3333 parts of
boiling water. It dissolves in potash-ley, and to fabrics impregnated
with alum or iron mordants, imparts the same shades of colour as madder;
the colours so produced withstanding soap but not chlorine.

Whether brilliant lakes could be obtained from the potash solution of
the red, and whether those reds would be stable, it might be worth while
to ascertain.

115. _Sandal Red._

We have kept this separate from other reds derived from woods, because
it is said (by Professor H. Dussance) to be obtainable not only equal in
beauty and brightness to carmine, but of greater permanence. The process
of preparation is as follows:--The powdered root exhausted by alcohol
gives a solution to which hydrated oxide of lead is added in excess. The
combination of colouring matter and lead oxide is then collected on a
filter, washed with alcohol, dried, dissolved in acetic acid, and mixed
with a quantity of water. The red being insoluble therein is
precipitated, while the acetate of lead remains dissolved. After being
washed, the colour is dried at a low temperature. The Professor affirms
that the red so produced is unaffected by sulphuretted hydrogen, or by
light and air; and it is stated that the colour which was used to paint
the carriages of the Emperor Napoleon, remained as bright at the end of
nine years as when it was put on. Possessing such properties, it is
curious that the red has never been--in this country at
least--introduced as an artistic pigment, the more especially as
seventeen years have elapsed since its discovery.

116. _Silver Red._

By adding monochromate of potash to an acid solution of nitrate of
silver, a particularly fine ochre-red is obtained. It is, however, apt
to be injured both by foul air and exposure.

117. _Sorgho Red._

Some nine years back there was found to be a carmine colouring matter in
most parts of the Chinese sorgho, chiefly in the unpressed stem. The
red, which is extracted in an impure state, is dissolved in weak
potash-ley, thrown down by sulphuric acid, and washed with water. This
purified product, soluble in alcohol, caustic alkalies, and dilute
acids, has been employed in Austria, Baden, &c., for the dyeing of silks
and woollens with the common tin mordants. The colours produced from it
are unchanged, they say, by warm soapsuds or light. We do not know
whether the red found its way to England, but it has certainly not
appeared here as a pigment.

118. _Thallium Red._

The orange-yellow precipitate formed by mixing a neutral salt of
protoxide of thallium with bichromate of potash, is converted by nitric
acid into an orange-red. The latter compound, which is a terchromate, is
almost insoluble in cold water, 2814 parts being required to dissolve
it. If the colour be boiled in a large excess of moderately strong
nitric acid it is dissolved, yielding magnificent cinnabar red crystals
on the solution cooling. These crystals likewise seem to be the
terchromate.

119. _Tin Pink._

By igniting strongly for some hours a mixture of stannic oxide, chalk,
chromate of potash, and a little silica and alumina, a dingy red mass is
obtained, which acquires a beautiful rose-red colour on being washed
with water containing hydrochloric acid. For the same reason that the
pinks of cobalt are superfluous as artistic pigments, this tin product
is commercially ineligible. Having, however, the advantage of being
cheap, and being probably durable, it would be well adapted for the
common purposes of painting, in place of the fugitive rose pink.

120. _Ultramarine Red?_

In Gmelin's Handbook of Chemistry it is remarked that "Hydrogen gas
passed over ignited ultramarine, colours it light red, from formation of
liver of sulphur, hydrosulphuric acid gas and water being evolved at the
same time." On most carefully making the experiment with a sample of
native blue (the variety referred to) we did not succeed in effecting
this change: no alteration to red or even to purple took place, the only
result being that the colour was entirely spoilt, having assumed a
leaden slate-gray hue. At our request, the trial was kindly repeated by
well-known chemists, who took every precaution to ensure success.
Several specimens of ultramarine were acted upon, but in no case was a
red or anything like a red obtained, the products ranging from a
slate-gray to a drab-grey. Sufficient hydrosulphuric acid gas was
evolved to blacken paper moistened with acetate of lead, a fact which
proved that the blue had lost some of its sulphur. Seeing that not only
no red was produced, but that no tendency to red was imparted, is it
possible the change described by Gmelin occurred under exceptional
circumstances? All conversant with chemical matters will admit that
results are obtained occasionally which cannot be repeated, owing it may
be to some slight difference in the materials employed, or some slight
variation of the process. Perhaps a link, considered of no importance
at the time and overlooked, has been lost, and thus the whole chain of
proceeding becomes useless. It is, therefore, within the bounds of
probability that the red ultramarine of the great German chemist was
furnished either by a peculiar specimen of blue, or by a modified form
of the method he gives. We have noticed the subject at some length
because if a red ultramarine, brilliant and durable, could be obtained,
the colour might prove of value. A permanent artificial compound
corresponding to French blue would certainly be an acquisition.

121. _Uranium Red._

By treating the yellow sulphite of uranium with a prolonged current of
sulphuretted hydrogen, and saturating gradually with ammonia, a red
finally results. This colour is insoluble in water, and it has the
objection of remaining partially suspended for an almost indefinite
time, colouring the liquid light red. The product is brighter and more
beautiful while moist; when dried and powdered, its tone--slightly
approaching vermilion--is duller. The colour may be obtained of several
degrees of brilliancy, but, apart from the question of expense, it would
be inadmissible in oil, the red gradually altering by contact therewith.
The most persistent tint at length resembles burnt Sienna.

122. _Wongshy Red._

There was imported a few years ago from Batavia a new colouring
principle, under the name of _wongshy_, and consisting of the
seed-capsule of a species of gentian. The aqueous extract, freed from
the pectin which it contains, yields with baryta- and lime-water yellow
precipitates, from which acids separate the colouring matter of a
vermilion hue. When thus prepared it is insoluble in water, and would so
far be adapted for a pigment. The red has not, however, been employed as
such, and we are unacquainted with its habitudes.

       *       *       *       *       *

The concluding remarks appended to the chapter on yellow apply equally
to red, and indeed to all other colours. It is not assumed that the list
is exhausted: there are other reds, but they are, like some we have
mentioned, ineligible as pigments, either by reason of their fugacity,
their costliness, the difficulty of producing them on a scale, or the
sources whence they are derived being commercially unavailable. While
endeavouring throughout the work to render complete the collection of
pigments actually in use, it is our object to give a selection only of
numbered italicised colours; ample enough, however, to include those
which have become obsolete or nearly so, and full enough to afford some
insight into our resources. The nearer we approach perfection, the more
eager we are to arrive at it: the path before us, therefore, cannot fail
to be of interest.

Looking back, and noting those pigments commonly employed, we find that
the reds like the yellows are divisible into three classes--the good,
bad, and indifferent; or the permanent, the semi-stable, and the
fugitive.

Among permanent reds, rank cadmium red, madder reds, Mars red, the
ochres, and vermilions.

In the second or semi-stable class, must be placed cochineal lakes,
Indian lake, and red chrome.

To the third division, or the fugitive, belong dragon's blood, pure
scarlet, red lead, and the coal-tar reds.

With regard to the foregoing classification, it must be borne in mind
that the properties and effects of pigments are much influenced by
adventitious circumstances. Sometimes pigments are varied or altogether
changed by the grounds on which they are employed, the vehicles in which
they are used, the siccatives and colours with which they are mixed, and
the varnishes by which they are covered. And as there is no exact and
constant agreement in different specimens of like pigments, so there is
no exact and constant result in their use. Artists vary as much as the
pigments they employ: some resemble the old masters in the delicacy with
which they treat their colours, the cleanliness with which they surround
them, and the care with which they compound them: in the hands of such
artists pigments have every chance. Some, however, are characterized by
a careless manipulation, a dirty mode of working, an utter disregard for
all rules of admixture: with such painters the best colours may be
ruined. And here, indeed, it may be asked, whether these latter are not
more properly termed painters than artists, chiefly belonging as they do
to that slap-dash school which manufactures pictures simply to sell
them. Duly subordinated, the commercial side of art has a value which it
were affectation to ignore; but to paint merely for the present,
heedless of the future, is to sink art to the level of a trade, not the
most honest. For it is the purchaser who suffers from the want of
thought bestowed on the materials, the sloppy manipulation, the careless
compounding; sins of omission and commission that cause him, on finding
his picture becoming chaos, to join the detractors of modern pigments.
In classifying colours therefore, those also should be classified who
use them:--into artists, whose love for art would render it more lasting
than themselves; and into painters, whose motto is _Vita brevis est, Ars
quoque_.




CHAPTER X.

ON THE PRIMARY, BLUE.


The third and last of the primary or simple colours is _blue_, which
bears the same relation to shade as yellow to light. Hence it is the
most retiring and diffusive of all colours, except purple and black; and
all colours have the power of throwing it back in painting, to a greater
or less extent, in proportion to the intimacy of their relations to
light--first white, then yellow, orange, red, &c.

Blue alone possesses entirely the quality technically called 'coldness'
in colouring, and it communicates this property variously to all other
colours with which it happens to be compounded. Most powerful in a
strong light, it seems to become neutral and pale in a declining light,
owing to its ruling affinity with black or shade, and its power of
absorbing light. Consequently, the eye of the artist is liable to be
deceived when painting with blue in too low a light, or toward the close
of day, to the endangering of the warmth and harmony of his picture.
Entering into combination with yellow in the composition of all
_greens_, and with red in all _purples_, blue characterizes the tertiary
_olive_, and is also the prime colour or archeus of the neutral _black_,
&c., as well as of the semi-neutral _gray_, &c.: it therefore is changed
in hue less than any other colour by mixture with black, as it is
likewise by distance. Blue is present subordinately in all tertiary and
broken colours, and being nearest in the scale to black, breaks and
contrasts powerfully and agreeably with white, as in pale blues, skies,
&c. Being less active than the other primaries in reflecting light, it
is sooner lost as a local colour by assimilation with distance. There is
an ancient doctrine that the azure of the sky is a compound of light and
darkness, and some have argued hence that blue is not a primary colour,
but a mixture of black and white; but pure or _neutral_ black and white
compound in infinite shades, all of which are neutral also, or _grey_.
It is true that a mixture of black and white is of a _cool_ hue, because
black is not a primary colour, but a compound of the three primary
colours in which blue predominates, a predominance which is rendered
more sensible when black is diluted with white. As to the colour of the
sky, in which light and shade are combined, that is likewise neutral,
and never blue except by contrast; thus, the more the light of the sun
partakes of a golden or orange hue, and the more parched and burnt the
earth is, the bluer appears the sky, as in Italy and all hot countries.
In England, where the sun is cooler, and a perpetual verdure reigns,
infusing blue latently into the landscape, the sky is warmer and nearer
to neutrality, partaking of a diversity of greys, which beautifully
melodize with blue as their key, and harmonize with the light and
landscape. Therefore the colour of the sky is always a contrast to the
direct and reflected light of the scene: if this light were of a rose
colour, the neutral of the sky would be converted into green, or if
purple, the sky would become yellow. Similarly would it be in all cases,
according to the laws of chromatic equivalence and contrast, as may be
often seen in the openings of coloured clouds at the rising and setting
of the sun.

In art, blue is apt to be discordant in juxtaposition with green, and
less so with purple, both which are cool colours; consequently blue
requires its contrast, _orange_, in equal proportion whether of surface
or intensity, to compensate or resolve its dissonances and correct its
coldness. In nature, however, blue is not discordant with either green
or purple, nor are any two colours (as we have said before) ever found
so. On the palette of nature each _colour_ is an example of _colouring_:
no colour is too absolute or defined, no perfectly pure blue appears
beside a perfectly pure green. A blue flower nestled in its green leaves
does not offend the nicest eye, but the blue and green are not blue and
green alone. There is, perhaps, but a single gleam of pure colour in
each: the rest is composed of such varied hues and tints and shades, so
broken and blended and beautifully harmonized, that no jarring discord
is possible. Hue melts into hue, tint into tint, shade into shade; and
thus does the simplest weed teach a lesson in colouring the proudest
painter may stoop to learn.

We have spoken of blue, which is termed a cold colour, as retiring; and
of yellow and red, which are called warm colours, as advancing. By this
we must not be understood to mean that blue, as blue, expresses
distance; or that yellow and red, as yellow and red, express nearness.
Colours are advancing or retiring in their _quality_--as depth,
delicacy, &c., not in their hue. A blue object set side-by-side a yellow
one will not look an inch farther off, but a red or orange cloud, in the
upper sky, will always seem to be beyond a blue cloud close to us, as it
is in reality. We grant that in certain objects, blue is a _sign_ of
distance, but that is not because blue, as a mere colour, is retiring;
but because the mist in the air is blue, and therefore any warm colour
which has not strength of light enough to pierce the mist is lost or
subdued in its blue. Blue in itself, however, is no more, on this
account, retiring, than brown is retiring, because when stones are seen
through brown water, the deeper they lie, the browner they appear.
Neither blue nor yellow nor red possesses, as such, the smallest power
of expressing either nearness or distance; they merely express
themselves under the peculiar circumstances which render them at the
moment, or in that place, signs of nearness or distance. Thus, purple in
a violet is a sign of nearness, because the closer it is looked at the
more purple is seen; but purple in a mountain is a sign of distance,
because a mountain close at hand is not purple, but green or grey. It
may, indeed, be generally assumed that a tender or pale colour will more
or less denote distance, and a powerful or dark colour nearness; but
even this is not always so. Heathery hills will usually give a pale and
tender purple near, and an intense or dark purple far away: the rose
colour of sunset on snow is pale on the snow at one's feet, but deep and
full on the snow in the distance; and the green of a Swiss lake is pale
in the clear waves on the beach, but intense as an emerald in the
sunstreak, six miles from shore. And in any case, when the foreground is
in strong light, with much water about it or white surface, casting
intense reflections, all its colours may be perfectly delicate, pale,
and faint; while the distance, when it is in shadow, may relieve the
whole foreground with deepest shades of purple, blue green, or
ultramarine blue.

There is one law, however, about distance, which has some claims to be
considered constant, namely, that dulness and heaviness of colour are
more or less indicative of nearness. All distant colour is pure colour:
it may not be bright, but it is clear and lovely, not opaque nor soiled;
for the air and light coming between us and any earthy or imperfect
colour, purify or harmonize it; hence a bad colourist is peculiarly
incapable of expressing distance. It is not of course meant that bad
colours are to be used in the foreground by way of making it come
forward; but only that a failure in colour there will not put it out of
its place. A failure in colour in the distance will at once do away with
its remoteness; a dull-coloured foreground will still be a foreground,
though coloured badly; but an ill-painted distance will not be merely a
dull distance, it will be no distance at all.

This seeming digression is not out of place, as it will enable the
artist better to understand that it is in their quality, not in their
hue, that colours are advancing or retiring; and that he must rely on
the depth, delicacy, &c., of his pigments, and not simply on their
colours, to produce effects of distance.

Of all colours, except black, blue contrasts white most powerfully. In
all harmonious combinations of colours, whether of mixture or
neighbourhood, blue is the natural, prime, or predominating power.
Accordingly, blue is universally agreeable to the eye in due relation to
the composition, and may more frequently be repeated therein, pure or
unbroken, than either of the other primaries; whence the employment of
ultramarine by some masters throughout the colouring of a picture.

Blue pigments, like blue flowers, are more rare than those of the other
primary colours. In permanent blues the palette is very deficient, the
list being exhausted when the native and artificial ultramarines and the
cobalts have been mentioned. That there is room for new blues, durable
and distinct, cannot therefore be denied. A good addition has been made
of late years in the German _Coëlin_, known here as Cerulian Blue and
Coeruleum. What is chiefly wanted, however, is a colour combining the
wonderful depth, richness, and transparency of Prussian blue with the
strict stability of ultramarine. A permanent Prussian blue would be the
most valued gift the palette could receive.


COBALT BLUES

comprise _Cerulian Blue_ or _Coeruleum_, _Cobalt Blue_, _Smalt_,
_Royal Blue_, _Dumont's Blue_, _Saxon Blue_, _Thénard's Blue_,
_Leithner's Blue_, _Hungary Blue_, _Dutch Ultramarine_, _Zaffre or
Enamel Blue_, _Vienna Blue_, _Paris Blue_, _Azure_, &c., and are
obtained by the action of heat on mixtures of earthy or metallic bases
with cobalt. They are divisible into three classes--the stannic cerulian
blue, the aluminous cobalt blues, and the siliceous smalts. Of these,
the first possesses the least depth; the second hold a middle position;
while the third are marked by exceeding richness. Although not to be
ranked with ultramarine, the stannic and aluminous blues may be
described as durable, or at least as durable rather than semi-stable.
There are, as we have before observed, different degrees of permanence,
and the blues in question are not readily affected. With regard to
smalts, they are, as artist's pigments, inferior in stability to other
blues of cobalt.

123. CERULIAN BLUE,

or _Coeruleum_. Under the name Coëlin there has of late years been
imported from Germany the cobalt blue with a tin base to which reference
has just been made. This comparatively new pigment--which likewise
contains or is mixed with gypsum, silica, and sometimes magnesia--has
the distinctive property of appearing a pure blue by artificial light,
tending neither to green on the one hand nor to purple on the other.
This advantage, added to its permanence, has conferred a popularity upon
coeruleum which its mere colour would scarcely have gained for it. A
light and pleasing blue, with a greenish-grey cast by day, it possesses
little depth or richness, and is far excelled in beauty by a good
aluminous cobalt. A certain chalkiness, moreover, somewhat detracts from
its transparency, and militates against its use in water. It is in oil,
and as a night colour, that coeruleum becomes of service, as our
present system of lighting picture galleries by gas affects the purity
of blues generally. If those galleries were illuminated by means of the
electric light, we have it on the authority of Chevreul that all colours
and shades would show as well as by day: the same purpose would be
answered by the magnesium light. Some artificial lights are the ruin of
colours; in the soda flame (alcohol and salt) for instance, yellow
chromate of lead appears white, while red ochre and aniline blue appear
black.

Like other blues of cobalt, coeruleum assumes a greenish obscurity in
time, but like them it resists for a lengthened period both the action
of light and impure air, although chemically it is more open to the
influence of the latter, owing to its tin base. In admixture it may
safely be employed, as well as in fresco or enamel. For stage skies,
&c., in high-art scenery, the blue is admirably adapted. Now that there
are so many scene-painters who are artists--and so many artists who are
scene-painters--in bringing Nature to the foot-lights the effect of gas
on colours is of importance.

124. COBALT BLUE,

to which the various appellations have been given of _Thénard's Blue_,
_Vienna Blue_, _Paris Blue_, _Azure_, _Cobalt-Ultramarine_, &c., is the
name now exclusively confined to that preparation of cobalt which has a
base of alumina. It may, therefore, be not improperly called a blue
lake, the colour of which is brought up by fire, in the manner of enamel
blues. The discovery of this important pigment was made in 1802 by M.
Thénard, who obtained it by calcining a well-combined mixture of alumina
and crystals of cobalt. There may be employed with the aluminous base,
either the arseniate, the borate, or the phosphate of cobalt; but the
latter in preference, as it produces the purest colour. The arseniate
has always a violet tinge, more visible by gas-light than by day; while,
on account of the arsenic, the blue is more apt to be greened by impure
air, by reason of the formation of yellow sulphide of arsenic. The
purity of the colour, however, does not altogether depend on the
compound of cobalt used; in a great measure--as with other pigments--it
rests on the purity of the materials. To obtain a perfect blue, neither
inclining to purple nor green, the cobalt and alumina should be freed
from iron, and the former, as much as possible, from nickel also. With
the absence of these and proper skill, a true and brilliant blue may be
produced, almost rivalling the finest ultramarine. Apart, too, from its
increased beauty, a cobalt blue containing no iron or nickel is of
greater permanence than the ordinary products, being less liable to that
greenness and obscurity which time confers.

Though not possessing the body, transparency, and depth of ultramarine,
nor its natural and modest hue, commercial cobalt blue works better in
water than that pigment in general does; and is hence an acquisition to
those who have not the management of the latter. Resisting the action of
strong light and acids, its beauty declines by time, while impure air
greens and ultimately blackens it. Nevertheless, these changes are not
readily effected, especially in well made samples full of colour, and
sometimes the green tone is mechanically imparted. What wheat is to a
loaf, colour is to a pigment--it has to be ground and made up for use;
in the one vehicle to be mixed with gums, in the other with oils. It
often happens that colours have an antipathy to the latter, and refuse
to compound kindly therewith. Occasionally this repugnance manifests
itself in a few days, occasionally not for months. We know of a green
which flatly declines to have anything to do with oils, sinking and
separating therefrom in the course of a week, and leaving the clear oil
on the top. Repeatedly have colours to be coaxed to behave themselves as
pigments, coaxed not to 'run,' to work well, to dry well, &c.; and in
the humouring of their likes and dislikes the skill and patience of the
artist-colourman are sometimes severely taxed. Given a colour, it might
puzzle most chemists to convert it into a pigment; luckily Commerce
lends her aid. Lasting success, it is true, does not always follow, and
oils will rise to the surface now and then, giving green hues to blues,
orange hues to reds, and buff hues to yellows. Hence changes of colour
have been imputed before now to chemical alteration, when in reality the
results have been physical, caused by the subsidence of the pigments,
and the floating of the vehicles employed.

Cobalt blue dries well in oil, does not injure or suffer injury from
pigments in general, and may be used with a proper flux in enamel, as
well as in fresco. It affords clear bright tints in skies and distances,
but is apt to cause opacity if brought too near the foreground, and to
assume a violet tinge by artificial light. With madder brown it yields a
range of fine pearly neutrals; and with light red, in any proportion,
gives beautiful cloud tints. In combination with aureolin and sepia, or
rose madder, cobalt furnishes most agreeable and delicate tints for
distant trees, when under the influence of a soft light, or hazy state
of the atmosphere. In water-colour painting, cobalt is tolerably firm on
paper, and consequently answers better for some purposes than French
blue. In middle distances, if the cobalt possess a tendency to
chalkiness, the addition of a little indigo is a good corrective,
especially where the blue tone is required to be sombre and dark: it
should, however, be observed that the change is but temporary, indigo
being a fugitive pigment. In marine painting in water-colours, cobalt is
most useful for the remotest parts of seas and headlands. When dry, it
can be changed by going over it with a slight wash of vermilion or light
red, whereby a prismatic character is realized. Any strength of tone can
be obtained by repeating the washes, and should the colour be too
powerful, it may be reduced by pouncing it with a soft wet sponge; or if
too cold and blue, by a thin wash of burnt Sienna, merely the water
stained.

The blues of cobalt, on whatever base they may be prepared, are
distinguished from native and artificial ultramarines by not being
decolorised by acids.

125. SMALT,

Invented about the year 1540, in Saxony, is a vitreous compound of
cobalt and silica, in fact a blue glass. Since the fifteenth century,
cobalt has been used in different parts of Europe to tinge glass; and
so intense is the colouring power of its oxide, that pure white glass is
rendered sensibly blue by the addition of one thousandth part, while one
twenty-thousandth part communicates a perceptible azure tint. In common
with cobalt blue, the name _Azure_ has sometimes been given to it.
Varying exceedingly in quality and colour, the rougher kinds have been
employed by the laundress, and in the making of porcelain, pottery,
stained glass, encaustic tiles, &c.; as well as to cover the yellow
tinge of paper. For this last purpose, however, smalt is not perfectly
adapted, the colour being difficult to lay on uniformly, and the paper
when written on blunting the nibs of pens. Hence it has been superseded
to a great extent by artificial ultramarine, the presence of which may
be detected by the yellow spot which a drop of acid leaves on the paper.

A coarse gritty texture is peculiar to smalt, whether it be the _Powder
Blue_ of the washtub and _Blue Sand_ of the pottery, or the _Dumont's_
and _Royal Blue_ of the artist and high-class manufacturer. But the
strict stability which is a feature in smalt when used for painting on
glass and enamel does not follow it to the studio: both in water and oil
its beauty soon decays, as is often the case with other vitrified
pigments; nor is it in other respects eligible, being, notwithstanding
its richness and depth, very inferior to the cobalts preceding. It may
seem a paradox that the same colour should be at once so durable and so
fugitive, but we may briefly explain it by saying _when vitreous
pigments are reduced to that extreme state of division which the palette
requires, they lose the properties they possess in a less finely divided
state_. The best smalt in lumps appears black, yields a blue powder on
grinding, becomes paler on further grinding, and may be almost
decolourised by continued and excessive grinding. Smalt, it has been
stated, is merely a blue glass; and when a piece of blue glass, or a
blue crystal of sulphate of copper, is reduced to the fineness of flour,
the blue is lost. In vitrified and crystallised compounds, colour
depends on cohesion: sufficiently separate the particles, and the colour
more or less disappears. Not only, moreover, does grinding effect an
optical change in vitreous pigments, but it imposes further alteration.
That colour which was safe when locked up in a mass, crushed to minute
atoms is no longer so: imbedded in glass or enamel it will endure for
ages, but ground to impalpable powder becomes as liable to influence as
though it had never been subjected to heat at all. To sum up, vitreous
pigments are durable in a coarse or compact form, but are not more
stable than others when reduced to extreme division. As far as regards
artists' colours, therefore, vitrification does _not_ impart
permanence.

The grittiness to which we have referred is one of the defects of smalt,
which cannot, consistently with preserving its colour be entirely freed
from that drawback--an objection which pertains to vitreous pigments in
general. Hence it does not wash well, and in mural decoration is
sometimes applied to work by strewing the dry powdered colour upon a
flat ground of white or blue oil paint immediately after the latter is
laid on, whilst it yet remains wet. Of little body, it is a vivid and
gorgeous blue; bright, deep, and transparent, bordering on the violet
hue. It is chiefly employed in illumination and flower painting. The
inferior kinds of smalt are occasionally adulterated with chalk.

126. CYANINE.

Beckmann is fully convinced that the _cyanus_ of Theophrastus and the
_coeruleum_ of Pliny were a blue copper earth. However that may be, in
these days both names signify cobalt compounds, coeruleum being a
stannate of cobalt, and cyanine a mixture of cobalt and Prussian blue.
Unlike the former, cyanine, being composed of two old colours, can lay
no claim to originality. In the fourth chapter it was observed, "it is
quite possible for the artist to multiply his pigments unnecessarily.
Colours are sometimes brought out under new names which have no claim to
be regarded as new colours, being, indeed, mere mixtures. Compound
pigments like these may most frequently be dispensed with, in favour of
hues and tints composed extemporaneously of original colours upon the
palette." Whether these remarks are applicable to cyanine or not is a
question for artists to decide: in our opinion, with so many semi-stable
original pigments, the introduction of semi-stable compounds is to be
deprecated. Cyanine is a rich, deep, transparent blue, but its richness
and depth, as well as to a great extent its transparency, depend upon
Prussian blue, which is not strictly stable. Hence the peculiar
properties of cyanine remain unchanged only so long as the Prussian blue
itself, the pigment losing its colour by degrees on exposure to air and
light, and gradually assuming the tint of the paler but more permanent
cobalt. A mixture, be it remembered, necessarily partakes of the
qualities of its constituents, and if one of these be fugitive, the
compound cannot preserve its original hue.

Within the last few years, a compound similar to cyanine has appeared,
under the name of _Leitch's Blue_.

127. INDIGO,

or _Indian Blue_, was known to the ancients under the name of _Indicum_,
whence its present appellation. In modern Europe, it first came into
extensive use in Italy; but about the middle of the sixteenth century,
the Dutch began to import and employ it in considerable quantity.
Present in the woad plant, which is a native of Great Britain, indigo is
chiefly derived from a genus of leguminous plants called _Indigofera_,
found in India, Africa, and America. The colouring matter of these is
wholly in the cellular tissue of the leaves, as a secretion or juice;
not, however, in the blue state in which one is accustomed to see
indigo, but as a colourless substance, which continues white only so
long as the tissue of the leaf remains perfect: when this is by any
means destroyed, oxygen is absorbed from the atmosphere, and the
principle becomes blue. The best indigo is so light as to swim upon
water, but the commercial article seldom contains more than 50 per cent.
of blue colouring matter or true indigo, the remainder consisting of
either accidental or intentional impurities.

In painting, indigo is not nearly so bright as Prussian blue, but it is
extremely powerful and transparent, and may be described as a Prussian
blue in mourning. Of great body, it glazes and works well both in water
and oil. Its relative permanence as a dye has obtained it a false
character of extreme durability as a pigment, a quality in which it is
nevertheless very inferior even to Prussian blue. By impure air it is
injured, and in glazing some specimens are firmer than others, but not
durable; while in tint with white lead they are all fugitive. Employed
in considerable body in shadow, it is more permanent, but in all
respects Prussian blue is superior.

Despite this want of stability, indigo is a favourite colour with many
artists, who sacrifice by its use future permanence to present effect.
It is so serviceable a pigment for so many purposes, especially in
admixture, that its sin of fugacity is overlooked. Hence we find indigo
constantly mentioned in works on painting, their authors forgetting or
not caring to remember that wholesome axiom, a fugitive colour is not
rendered durable by being compounded. Artistically, it is adapted for
moonlights, and when mixed with a little lamp black, is well suited for
night clouds, distant cliffs, &c. With a little raw umber and madder it
is used for water in night effects. With the addition of a little madder
it forms a good gray; and with madder and burnt Sienna is useful for
dark rocks, this combination, with raw Sienna, being also eligible for
boats. For these and other mixed tints, however, Prussian blue saddened
by black with a suspicion of green in it, is equally fitted, and is more
permanent. Indeed, it would be perhaps justifiable to introduce such a
compound, under the name say, of Factitious Indigo.

Indigo in dust, or in small bits, is often adulterated with sand,
pulverized slate, and other earthy substances. That indigo is best which
is lightest, brightest, most copper-coloured, most fine-grained, and
inodorous.

128. INTENSE BLUE

is indigo refined by solution and precipitation. By this process, indigo
becomes more durable, and, being separated from impurities, is rendered
much more powerful, transparent, and deep. It washes and works admirably
in water; in other respects it possesses the common properties of
indigo. It is apt, however, to penetrate the paper on which it is
employed, if not well freed by washing from the acid and saline matter
used in its preparation. This is not always easily effected, and we
cannot help thinking that in the manufacture of intense blue a dry
method would be preferable. Indigo may, by cautious management, be
volatilized, and therefore be most thoroughly purified without the aid
of acids and alkalies. The best mode of subliming this substance is to
mix one part of indigo with two parts of plaster of Paris, make the
whole into a paste with water, spread it upon an iron plate, and, when
quite dry, heat it by a spirit lamp. The volatilization of the indigo
is aided by the vapour of water disengaged from the gypsum, and the
surface of the mass becomes covered with beautiful crystals of pure
indigo, which may be readily removed by a thin spatula. At a higher
temperature, charring and decomposition take place.

129. PRUSSIAN BLUE,

otherwise called _Berlin Blue_, _Paris Blue_, _Prussiate of Iron_,
_Ferrocyanide of Iron_, &c., was accidentally discovered in 1710 by
Diesbach, a colour-maker at Berlin. It is a compound of iron and
cyanogen, of varying composition, formed by adding yellow prussiate of
potash to a persalt of iron, or by oxidizing the precipitate obtained
from the prussiate and a protosalt. The finest blue is furnished by
sesquinitrate of iron, but the salt almost exclusively employed is the
protosulphate, the freedom of which from copper is essential to the
colour of the blue. As is the case with other pigments, Prussian blue
differs considerably in colour, in depth, and in permanence, according
to the purity of the materials, the mode of manufacture, and the absence
of adulterants. Like smalt, it is known in the washtub as well as in the
studio; and in the cheaper varieties, alumina, starch, chalk, oxide of
iron, &c., are often largely present. A good unsophisticated sample in
the dry state is intense blue, almost black, hard and brittle, much
resembling in appearance the best indigo, and having a similar
copper-red fracture. It does not effervesce with acids, as when
adulterated with chalk; nor become pasty with boiling water, as when
sophisticated with starch. Further, it feels light in the hand, adheres
to the tongue, is inodorous, tasteless, not poisonous, and is insoluble
in water. Forming a bulky mass while moist, Prussian blue shrinks to a
comparatively small compass when well washed and dried by gentle heat;
and, when once dried, being difficult to reduce again to the state of
extreme division which it possessed while wet, it is frequently sold and
used in paste for common purposes. We have said that a good sample of
Prussian blue is insoluble in water, and for artistic use it should
certainly be so, as otherwise it has a tendency to stain the fabric on
which it is employed, a defect formerly very prevalent. All Prussian
blues, however, are not insoluble, and these are not only liable to the
drawback named, but are less to be depended on for permanence. Improper
proportions, for instance, of sesquichloride of iron and
potash-ferrocyanide will yield a blue which, when washed even with cold
water, continually imparts to it a yellow or green colour, through the
partial solution of the prussiate. All commercial Prussian blue, and
indeed that which is prepared by careful chemical processes, give up the
ferrocyanide to boiling water, thereby colouring it greenish yellow; but
a sample which parts with its prussiate to _cold_ water is quite
unfitted for the palette, for which the most perfect specimen is none
too stable.

In spite of the learned researches of Professor Williamson, whose name
is as closely connected with the pigment as are the names of Schunck and
De La Rue with madder and cochineal, Prussian blue is not yet entirely
understood. Complex and uncertain in composition, uncertain too in its
habitudes, our best course perhaps will be not to attempt a complete
survey, but to state briefly those facts which bear on the artist's
craft.

Prussian blue is a colour of vast body and wonderful transparency, with
a soft velvety richness, and of such intense depth as to appear black in
its deepest washes. Notwithstanding it lasts a long time under
favourable circumstances, its tints fade by the action of strong light;
becoming white, according to Chevreul, in the direct rays of the sun,
but regaining its blue colour in the dark; hence that subdued light
which is favourable to all colours is particularly so to this blue. Its
colour has the singular property of fluctuating, or of coming and going,
under certain conditions; and which it owes to the action and reaction
by which it acquires or relinquishes oxygen alternately. It also becomes
greenish sometimes by a development of the oxide of iron; and is
purpled, darkened, or otherwise discoloured by damp or impure air. Time
has a neutralizing tendency upon its colour, which forms tints of much
beauty with white lead, though they are not equal either in purity,
brilliancy, or permanence to those of cobalt and ultramarine. When
carefully heated, Prussian blue gives off water and assumes a pale green
hue; its colour, therefore, depending on the presence of water, must not
be exposed to a high temperature. And as it is likewise injured or
destroyed by alkalis, which decompose it into oxide of iron and a
soluble prussiate, the blue should be avoided in fresco, on account of
the lime; neither should it be employed with pigments of an alkaline
nature, nor with hard water containing bicarbonate of lime in solution,
but with clean rain or distilled water, either of which is preferable
for colours generally.

Prussian blue dries and glazes well in oil, but its great and principal
use is in painting deep blues, in which its body helps to secure its
permanence, and its transparency gives force to its depth. It is also
valuable in compounding deep purples with lake, and is a powerful
neutralizer and component of black, to the intensity of which it adds
considerably. Prussian blue borders slightly on green, a quality which
militates against its use in skies and distances. In spite, however, of
its want of, or deficiency in, durability, the old water-colour painters
so employed it, neutralized by the addition of a little crimson lake. It
is serviceable in mixed tints of greens, affording with light red a
sea-green neutral. Dissolved in oxalic acid, the blue is available as an
ink, or for tinting maps.

Besides the preceding, there is a _Basic Prussian Blue_, formed by
simply submitting to the air the bluish-white precipitate which falls on
adding yellow prussiate of potash to green vitriol. This compound
dissolves entirely by continued washing with water, yielding a beautiful
deep blue solution, from which the colour may be thrown down in a solid
form by the addition of any salt. Probably it was this basic
preparation, so cheaply and easily made, that conferred upon Prussian
blue the character of staining paper. In name, there is also another
variety of this pigment, known as _Native Prussian Blue_; which is
really a native phosphate of iron, occurring as a blue earthy powder, or
as a white powder that becomes blue by exposure.

130. ANTWERP BLUE,

_Haerlem Blue_, _Berlin Blue_, _Mineral Blue_, is a lighter and
somewhat brighter Prussian blue, with less depth and less permanence. It
is a species of lake, having a considerable proportion of aluminous
base, to which its paler tint is due. As the stability of Prussian blue
rests in a great measure on the marvellous amount of latent colour the
pigment contains, when its particles of colour are set farther apart by
the intervention of the alumina, the permanence of its hue is
endangered. It was remarked, with respect to vitrified pigments, that
colour depends on cohesion. More or less, this holds good as regards all
pigments; but not only, as was also observed, does colour rest on
cohesion, in many instances durability depends likewise. It is only when
a colour is stable in itself that its particles will bear separating:
native ultramarine, for example, may be weakened almost to white, and
will still preserve its hue. If, however, a colour be naturally
fugitive, and rely chiefly on its extreme depth for what permanence it
possesses, that colour cannot with impunity be paled: witness the
cochineal lakes, which the deeper they are, the more durable they are
found; and so it is with Prussian blue. Antwerp blue is distinguished
from the latter by its more earthy fracture.

131. TURNBULL'S BLUE,

Or _Ferricyanide of Iron_, is formed by adding the red prussiate of
potash to a protosalt of iron. This blue is lighter and more delicate
than ordinary Prussian blue, and is believed to resist the action of
alkalies longer. It is a question whether the common Prussian blue
obtained by oxidizing the precipitate yielded by green vitriol and the
yellow prussiate is not in reality this variety. However that may be,
there is, as far as permanence goes, little or no difference between the
two kinds.


ULTRAMARINES.

ARTIFICIAL ULTRAMARINES

comprise the varieties known as _French Ultramarine_, _French Blue_,
_Brilliant Ultramarine_, _Factitious Ultramarine_, _Guimet's
Ultramarine_, _New Blue_, _Permanent Blue_, _Gmelin's German
Ultramarine_, _Bleu de Garance_, _Outremer de Guimet_, &c. The
unrivalled qualities of native ultramarine prepared from the lapis
lazuli rendered it most desirable to obtain an artificial compound
which, while possessing similar properties, could be produced in
quantity, and at a less costly rate. In demolishing some furnaces
employed in making soda, by means of decomposing sulphate of soda, some
earth had been found impregnated with a light blue, which was proved to
have so close a resemblance to ultramarine as to foster hopes of
success. As a stimulus, there was offered a prize of six thousand francs
or £500 for the production of artificial ultramarine by the _Société
d'Encouragement_ of Paris, which was won in 1828 by M. Guimet. It is
fitting that the discoverer of a colour should excel in its manufacture,
and to this day Guimet's ultramarine is the finest made. As an instance
of how the researches of different men may, almost simultaneously, lead
to the same results, it is curious that very shortly after the problem
was also solved by Gmelin.

The cause of the blue colour of ultramarine was long a matter of
controversy, but was believed generally to be due to iron. When,
however, the discovery of artificial ultramarine was made, this
assumption was shown to be false, by the fact that a blue could be
obtained with materials perfectly free from iron. The absolutely
necessary constituents of ultramarine are silica, alumina, sulphur, and
soda; and there is little doubt that the colouring matter consists of
hyposulphite of soda and sulphide of sodium: it is certain that the blue
colour is dependant on the soda, inasmuch as potash yields an analogous
compound which is purely white. A number of substances, such as iron,
lime, magnesia, and potash, may be present as impurities, and were, in
part at least, purposely added to the earlier manufactures; but they are
found to be superfluous. Nevertheless, as regards iron, it is probable
that a very small portion, such as is usually contained in the
ingredients, greatly facilitates the production of the blue, and may
even be essential in some cases.

The colour of ultramarine is brought out by successive heatings. Green
portions, more or less in quantity, are often formed in the crucibles,
especially on the first ignition. On repeated heating they pass into a
blue tint. Artificial ultramarines are said to be seldom entirely freed
from all traces of the green modification, and are therefore less
beautiful than the natural varieties, having a shade of green or grey.
This defect, however, is certainly not discernible in Guimet's products,
which sometimes incline so much to purple as to require neutralizing
with a little Prussian blue. Depth for depth, the artificial are darker
and less azure than the natural varieties, but the superiority of the
latter consists not so much in their greater purity of hue, although
this is considerable, as in their far greater transparency. The finest
French ultramarine is never so transparent as the native; it is
brilliant, it is powerful, it is permanent, it is nearly--but only
nearly--transparent. Possessing in a subdued degree the characteristics
and qualities of the genuine, it works, washes, and dries well; and is
useful either in figures, draperies, or landscape. Rivalling in depth,
although not equalling in colour, the pure azure of native ultramarine,
it answers to the same acid tests, but is sometimes distinguished
therefrom by the effervescence which ensues on the addition of an acid.
Not a bubble escapes in such case from the natural blue; unless, indeed,
as occasionally happens, it retain a portion of alkali, with which it
may have been combined in the preparation, but from which it should have
been freed. Darkened as a rule by fire, factitious ultramarine becomes
dingy blue, and at last white, when strongly ignited for a long time;
and is, like the true variety, decolourised by ignition in an atmosphere
of hydrogen gas. At a high temperature, this effect is even produced by
silica, whence the unfitness of ultramarine for painting on glass or
porcelain; and simply by a prolonged red heat the blue is rendered
white. Being unaffected by alkalis, it is eligible in mural decoration,
and is particularly adapted to siliceous painting, on account of the
silica and alumina which it contains, two substances with which a
soluble silicate readily unites. If artificial ultramarine be mixed with
a soluble silicate, for example silicate of potash, and be laid on a
properly prepared ground, it will become so firmly fixed, says Mr.
Barff, that no amount of washing nor the slow action of moisture will
remove it, or affect its brilliancy. Judging from the behaviour of
ultramarine, therefore, if the colours employed in siliceous painting
contain silica and alumina, they should adhere as firmly to the surface
on which they are placed; and this is really the case. It is possible to
produce a mixed solution of aluminate and silicate of potash which will
remain liquid for twenty-four hours. If, while in the liquid state,
colours are saturated with this solution and allowed to dry, their
particles will be very intimately mixed with silica and alumina
chemically combined with potash. According to the author quoted, the
admixture of silica and alumina does not interfere with the brilliancy
or depth of the colours, and the method may be used for all those which
are not injured by potash, and are in themselves adapted to the art.

With respect to permanence, the finer varieties of artificial
ultramarines may, undoubtedly, be pronounced stable; but, like all other
colours, these blues are apt to vary in quality, and inferior kinds are
liable to lose their purity in a measure, and become grayer. Moreover,
they are made by different processes, and the mode adopted for the
manufacture of a pigment not only tells upon the colour, but may
influence to some extent its durability. From the following experiment
of an ingenious artist and friend of the author, it is evident that the
production of artificial ultramarine was not carried in its early days
to that state of perfection at which it has now arrived. He took a
picture, the sky of which had been recently painted in the ordinary
manner with Prussian blue and white; and having painted over the clear
part of the sky uniform portions with tints formed of the best
factitious ultramarine, cobalt blue, and genuine ultramarine, so as to
match the ground of the sky, and to disappear to the eye thereon by
blending with the ground, when viewed at a moderate distance, he set the
picture aside for some months. Upon examination, it appeared that the
colour of these various blue pigments had taken different ways, and
departed from the hue of the ground: the factitious ultramarine had
_blackened_, the cobalt blue _greened_, the genuine ultramarine remained
a _pure azure_, like a spot of light, while their ground, the Prussian
blue sky, seemed by contrast with the ultramarine of a _grey_ or _slate
colour_.

Other things being equal, those artificial ultramarines are most durable
which possess the most colour; and all are, perhaps, most permanent in
water. If used in that vehicle, care should be taken to employ a gum
free from acid; also, whether in water or oil, not to compound the blue
with a pigment which may possibly contain acid, such as constant white.
Acid, as we have said, is the great test for ultramarine; whence if a
sample be sophisticated with cobalt, its blue colour will not be
entirely destroyed. With high-class artistic pigments, however,
adulteration is the exception and not the rule. It is as a powder-blue
for the washtub that ultramarine gets disguised, when it is ground up
with soda-ash, chalk, gypsum, &c., and sold sometimes under its own
name, but more frequently as superfine Saxon smalts.

132. BRILLIANT ULTRAMARINE,

lately called _Factitious Ultramarine_, is a specially fine preparation
of M. Guimet, presenting the nearest approach to the natural product of
any artificial ultramarine, both in transparency, purity of hue, and
chemical characteristics. Equalling in depth and power the ordinary
French ultramarine, it possesses greater clearness, beauty, and
brightness; and has, in a subdued degree, that quality of light in it,
and of the tint of air, which forms so distinguishing a feature in the
native blue.

133. FRENCH ULTRAMARINE,

or _French Blue_, is a rich deep colour, but less transparent and vivid
than the preceding variety, which is preferable in unmixed tints. For
compound hues, French blue is sufficiently well adapted, and is
extremely useful. With aureolin and burnt Sienna, or Vandyke brown, it
affords valuable autumn greens; and with lamp black, or lamp black and
light red, good stormy clouds. A sombre gray for distant mountains is
furnished by French blue and madder brown, with a very little gamboge;
and a deep purple for sunsets, by the blue and purple madder, or Indian
red and rose madder. With cadmium and orient yellows, sepia, viridian,
and many other colours, this ultramarine is of service.

134. NEW BLUE

Is confined to water-colour painting, and is an artificial ultramarine,
holding a middle position between French blue and permanent blue, being
less deep than the one and less pale than the other. It may be said to
hover in tint between a rich ultramarine and cobalt.

135. PERMANENT BLUE

Is a pale ultramarine, with a cobalt hue; and, in spite of its name,
less permanence than belongs to the richer and deeper sorts. What
Antwerp blue is to Prussian blue, this is to French blue--that is, as
regards colour. With respect to durability, however, permanent and
Antwerp blues cannot be compared; the former being a weakened variety of
a stable, and the latter a weakened variety of a semi-fugitive, pigment.
Hence permanent blue justifies its name, although that name would be
more suited to the brilliant, or French, ultramarine.

136. GENUINE ULTRAMARINE,

_Native Ultramarine_, _Natural Ultramarine_, _Real Ultramarine_, _True
Ultramarine_, _Ultramarine_, _Pure _Ultramarine_, _Azure_, _Outremer_,
_Lazuline_, _Lazulite Blue_, and _Lazurstein_. This most costly, most
permanent, and most celebrated of all pigments, is obtained by isolating
the blue colouring matter of the _lapis lazuli_, a stone chiefly brought
from China, Thibet, and the shores of Lake Baikal. About the antiquity
of the stone, and its colour, much has been written, and many
conflicting statements have been made; but there is little doubt that
our lapis lazuli was the sapphire of the ancients; and that the first
certain mention of ultramarine occurs in a passage of Arethas, who lived
in the eleventh century, and who, in his exposition of a verse in the
book of Revelation, says, the sapphire is that stone of which
_lazurium_, as we are told, is made. It has been common to confound
ultramarine with the _cyanus_ and _coeruleum_ of the ancients; but
their cyanus, or Armenian blue, was a kind of mineral or mountain blue,
tinged with copper; and their coeruleum, although it may sometimes
have been real ultramarine, was properly and in general a copper ochre.
That ultramarine was known to the ancients there seems every
probability, for it is certain they were acquainted with the stone; and
modern travellers describe the brilliant blue painting still remaining
in the ruins of temples of Upper Egypt as having all the appearance of
ultramarine. Whether it is so or not, however, could only be proved by
analysis; for, be it recollected, although the colour had preserved its
hue during so many centuries, it had been completely buried, and
therefore most perfectly secluded from light and air. Mr. Layard, in his
'Nineveh,' referring to some painted plaster, remarks that "The colours,
particularly the blues and reds, were as brilliant and vivid when the
earth was removed from them as they could originally have been; but, on
exposure to the air, they faded rapidly." In all likelihood, these were
of organic, or semi-organic, origin, prepared in some such manner as
that mentioned by Pliny, who speaks of an earth which, when boiled with
plants, acquired their blue colour, and was in some measure inflammable.
As a pigment, cobalt was unknown to the ancients; but to these vegetable
and copper blues of theirs, a third blue may perhaps be added.
Experiments made upon blue tiles, found in a Roman tesselated
foot-pavement at Montbeillard, showed that the colour was due to iron.
M. Gmelin has proved that a blue tint can be imparted to glass and
enamel by means of iron; and it is probable that the ancients were first
induced by the blue slag of their smelting-houses to study the colouring
of glass with iron; that in this art they acquired a dexterity not
possessed at present, and that they employed their iron-smalt as a
pigment, as we do our smalt of cobalt. To sum up, there are grounds for
believing that the ancients were acquainted with copper blues,
vegetable blues, and iron blues; and that, consequently, the blue
described by travellers as having all the appearance of ultramarine may,
or may not, be that pigment.

Lapis lazuli, or lazulite, is usually disseminated in a rock, which
contains, among other substances, a fine white lazulite. In the _Musée
Minéralogique_ of Paris are two splendid specimens of the stone, in
which is seen the transition from the azure to the white. According to
the quantity and quality of blue present, the lapis varies from an
almost uniform tint of the deepest indigo-blue to grayish-white, dotted
and streaked at intervals with pale blue. The exceeding beauty of good
samples has caused the lazulite to be much sought after, both as a gem
for adorning the person, and for inlaid works in ornamental decoration.
In China the stone is highly esteemed, being worn by mandarins as badges
of nobility conferred only by the Emperor; and in the apartments of a
summer palace near St. Petersburg, the walls are covered with amber,
interspersed with plates of this costly lapis. Besides the colouring
principle of the lazulite, there are always more or less mica and iron
pyrites, the latter a lustrous yellow bisulphide of iron, which has
often been mistaken for pellets of gold. Having chosen portions of the
stone most free from these impurities, it is simply requisite to reduce
them to an impalpable powder to obtain a blue pigment; and probably this
was the original mode of preparing it before the discovery of the modern
process. This curious method, which is mechanical rather than chemical,
depends for its success on the character and proportions of the
materials employed, as well as on the nicety of working. When well
carried out, it perfectly isolates the blue from all extraneous matter,
yielding the colour at first deep and rich, then lighter and paler, and
lastly of that gray tint which is known by the name of Ultramarine Ash.
The refuse, containing little or no blue, furnishes the useful pigment,
Mineral Gray.

The immense price of ultramarine--or, as it was at first called, azurrum
ultramarinum, blue beyond-the-sea--was almost a prohibition to its use
in former times. It is related that Charles I. presented to Mrs.
Walpole, and possibly to Vandyke also, five hundred pounds worth of
ultramarine, which lay in so small a compass as only to cover his hand.
Even in these days, despite the introduction of artificial ultramarines,
the native product continues costly, commanding in proportion to its
intensity and brightness, from two to eight guineas an ounce. To say,
however, that the merits of the blue at least equal its expense, is to
give the genuine ultramarine no more than its due. It has, indeed, not
earned its reputation upon slight pretensions, being, when of fine
quality, and skilfully prepared, of the most exquisitely beautiful blue,
ranging from the utmost depth of shadow to the highest brilliancy of
light and colour,--transparent in all its shades, and pure in all its
tints. A true medial blue, when perfect, partaking neither of purple on
the one hand, nor of green on the other, it sustains no injury either by
damp and impure air, or by the intensest action of light, and is so
eminently durable, that it remains unchanged in the oldest paintings.
Drying well, working well in oil and fresco, ultramarine may be safely
compounded with pigments generally, excepting only an acid sulphate of
baryta or constant white. The blue has so much of the property of light
in it, and of the tint of air--is so purely a sky-colour, and hence so
singularly adapted to the direct and reflex light of the sky, and to
become the antagonist of sunshine--that it is indispensable to the
painter. Moreover, it is so pure, so true, so unchangeable in its tints
and glazings, as to be no less essential in imitating the marvellous
colouring of nature in flesh and flowers. To this may be added that it
enters so admirably into purples, blacks, greens, grays, and broken
hues, that it has justly obtained the character of clearing or carrying
light and air into all colours, both in mixture and glazing, as well as
gained a sort of claim to universality throughout a picture.

Nevertheless, ultramarine is not always entitled to the whole of this
commendation. Frequently it is coarse in texture, in which case it is
apparently more deep and valuable; yet such blue cannot be used with
effect, nor ground fine without injuring its colour. Again, it is apt to
be separated in an impure state from the lapis lazuli, which is an
exceedingly varying and compound mineral, abounding with earthy and
metallic parts in different states of oxidation and composition: hence
ultramarine sometimes contains iron as a red oxide, when it has a purple
cast; and sometimes the same metal as a yellow oxide, when it is of a
green tone; while often it retains a portion of black sulphuret of iron,
which imparts a dark and dusky hue. Occasionally, it is true, artists
have preferred ultramarine for each of these tones; still are they
imperfections which may account for various effects and defects of this
pigment in painting. Growing deeper by age has been attributed to
ultramarine; but it is only such specimens as would acquire depth in the
fire that could be subject to the change; and it has been reasonably
supposed that in pictures wherein other colours have faded, it may have
taken this appearance by contrast. Ultramarine, prepared from calcined
lapis, is not liable to so deepen; but this advantage may be purchased
at some sacrifice of the vivid, warm, and pure azure colour of the blue
produced from unburnt stone. We have frequently found ultramarine to be
darkened, dimmed, and somewhat purpled by ignition; and the same results
ensue, in many instances, when the lazulite is calcined. In burning the
stone, the sulphur of the pyrites is in a great measure expelled, and
during its expulsion has probably a deteriorating influence on the
beauty of the colour: our belief in this being so is strengthened by the
fact that certain samples of ultramarine, ignited with sulphur, were not
improved thereby. Similar effects are likewise caused by a careless or
improper mode of treatment, for the finest lapis may yield dingy blues,
containing particles of mica, metal, &c., and possessing a dull green,
black, or purple hue. Of course the perfection of the pigment is
dependant to a large extent upon the quality of the stone itself.

Though unexceptionable as an oil-colour, both in solid painting and
glazing, it does not work so well as some other blues in water; nor is
it, unless carefully prepared, so well adapted for mixed tints, on
account of a gritty quality, of which no grinding will entirely divest
it, and which causes it to separate from other pigments. When extremely
fine in texture, however, or when a considerable portion of gum, which
renders it transparent, can be employed to give connexion or adhesion
while flowing, it becomes no less valuable in water than in oil; but
when its vivid azure is to be preserved, as in illuminated manuscripts
and missals, little gum must be used. The fine greens, purples, and
grays of the old masters, are often unquestionably compounds of
ultramarine; and formerly it was the only blue known in fresco. Pure
ultramarine varies in shade from light to dark, and in hue from pale
warm azure to the deepest cold blue.

Native ultramarine consists of silica, alumina, sulphur, and soda; its
colouring matter seeming to be due to hyposulphite of soda and sulphide
of sodium. In these respects, as well as in that of being decolourised
by acids, the natural product resembles the artificial. As a precious
material, the former has been subject to adulteration; and it has been
dyed, damped, and oiled to enrich its appearance; attempts of fraud,
however, which may be easily detected. In the preceding edition of this
work the author adds--"and the genuine may be as easily distinguished
from the spurious by dropping a few particles of the pigment into
lemon-juice, or any other acid, which almost instantly destroys the
colour of the true ultramarine totally, and without effervescence." With
this statement, so far as it pretends to be a test for the two kinds, we
are not inclined to agree. Genuine ultramarine is always decolourised by
acids; but it depends on the mode and nicety of its preparation whether
it is decolourised without effervescence: that this is the case the
author himself admits in his article on artificial ultramarine.
Moreover, the "violent effervescence" which he describes as ensuing on
the latter being dropped into an acid, does not of necessity take place:
in M. Guimet's finest variety, the brilliant ultramarine, acid produces
little or no effervescence. Seeing, therefore, that both sorts are
decolourised by acids, and that both may or may not effervesce
therewith, the acid test must be considered fallacious. Experiments made
with different samples of each, showed that native ultramarines offered
greater resistance to acid than the artificial, taking longer to
decolourise; and that the residues of the first were in general of a
purer white than those of the last. It was also found that the brilliant
ultramarine, above referred to, was less readily decolourised than other
French or German kinds.

       *       *       *       *       *

137. _Blue Carmine._

In a former edition of this work there appeared the following:--"Blue
carmine is a blue oxide of molybdenum, of which little is known as a
substance or as a pigment. It is said to be of a beautiful blue colour,
and durable in a strong light, but is subject to be changed in hue by
other substances, and blackened by foul air: we may conjecture,
therefore, that it is not of much value in painting." In his estimate of
this colour the author was certainly right. It is formed when a
solution of bichloride of molybdenum is poured into a saturated, or
nearly saturated, solution of molybdate of ammonia. A blue precipitate
falls, which is a molybdate of molybdic oxide, hydrated, and abundantly
soluble in water. When dried, it furnishes a dark blue powder,
resembling powdered indigo, having a bitter, rough, metallic taste, and
reddening litmus strongly. The solubility of this hydrated oxide is
alone fatal to its employment as a pigment. It may, indeed, be rendered
comparatively insoluble in water by ignition; but the anhydrous oxide so
obtained is nearly black, and as a colour worthless.

A more eligible preparation is the molybdate of baryta, produced by
mixing solutions of molybdate of potash and acetate of baryta. A white,
flocculent precipitate results, which rapidly condenses to a crystalline
powder, and turns blue on ignition. It is, however, a costly compound,
of little merit, and not likely to come into use. It is insoluble in
water.

138. _Blue Ochre_,

which has been improperly called Native Prussian Blue, is a native
hydrated phosphate of iron of rare occurrence, found with iron pyrites
in Cornwall, and also in North America. What Indian red is to the colour
red, and Oxford ochre to yellow, this pigment is to the colour blue,
being sober and subdued rather than brilliant. It has the body of other
ochres, more transparency, and is of considerable depth. Both in water
and oil it works well, dries readily, and does not suffer in tint with
white lead, nor change when exposed to the action of strong light, damp,
or impure air. As far as its powers extend, therefore, it is an eligible
pigment, though not generally employed nor easily procured; it may,
however, be artificially prepared. Answering to similar acid tests as
ultramarine, it is distinguished therefrom by assuming an olive-brown
hue on exposure to a red heat.

139. _Cobalt Prussian Blue._

Gmelin states that yellow prussiate of potash yields with a solution of
oxalate of sesquioxide of cobalt a blue resembling Prussian blue--that,
in fact, there can be obtained a Prussian blue with a base of cobalt
instead of iron. In the moist state, the similarity is sufficiently
great, but when washed and dried, the product is, with us, a dingy slate
colour. Possibly, if such a blue could be produced, it might exceed in
permanence the ferro- and ferri-cyanides of iron. Of course the compound
would be much more expensive.


_Copper Blues_

are now seldom or never employed as artists' pigments. The following
are the principal varieties:--

140. _Bice_,

Blue Bice, Iris, Terre Bleu, was prepared, when true, from the Armenian
stone, which is a calcareous kind of stone coloured with copper. It was
of a light bright hue, but is completely superseded by pale ultramarine.
The Persian lazur appears to have been a similar pigment, being a sort
of copper ore, which, when the stone was pounded and sifted, furnished a
fine paint, very bright and pleasant. It could not, however, stand the
effects of the atmosphere like the Tartarian lazur or lapis lazuli, in
the course of time becoming of a dark and dismal colour.

Ground smalts, blue verditer, and other pigments, have passed under the
name of bice.

141. _Blue Ashes_, or _Mountain Blue_,

are both hydrated carbonates of copper, the first being artificially
prepared, and the second found native in Cumberland. Neither is durable,
especially in oil; and, as pigments, both are precisely of the character
of verditer. By treating the natural malachite green with an alkali, it
may be converted into blue.

142. _Blue Verditer_,

or Verditer, is an oxide of copper, formed by precipitating nitrate of
copper with lime. It is of a beautiful light blue colour, little
affected by light, but greened and ultimately blackened by time, damp,
and impure air--changes which ensue even more rapidly in oil than in
water. It is mostly confined to distemper painting and paper-staining.

143. _Egyptian Blue_,

called by Vitruvius, Coeruleum, is frequently found on the walls of
the temples in Egypt, as well as on the cases enclosing mummies. Count
Chaptal, who analysed some of it discovered in 1809 in a shop at
Pompeii, found that it was blue ashes, not prepared in the moist manner,
but by calcination. He considers it a kind of frit, of a semi-vitreous
nature; and this would appear to be the case from Sir H. Davy obtaining
a similar colour by exposing to a strong heat, for two hours, a mixture
of fifteen parts of carbonate of soda, twenty of powdered flints, and
three of copper. The colour is very brilliant when first made, and
retains its hue well in distemper and decorative painting; but it has
the common defect of copper blues of turning green in oil, when ground
impalpably for artistic use. One remarkable effect of this copper
smalt--for it is nothing else--is, that by lamp-light it shows somewhat
greenish, but shines by day with all the brightness of azure. Mérimée
believes that Paul Veronese employed this sort of blue in many of his
pictures where the skies have become green.

144. _Saunders Blue_,

a corrupt name from _Cendres Bleues_, the original denomination probably
of ultramarine ashes, is of two kinds, the natural and artificial. The
first is a blue mineral found near copper mines, while the last is
simply a verditer.

145. _Schweinfurt Blue_,

or Reboulleau's Blue, is prepared by fusing together equal weights of
ordinary arseniate of protoxide of copper and arseniate of potash, and
adding one-fifth its weight of nitre to the fused mass. The result is,
so to speak, a sort of blue Scheele's green, into which latter colour it
soon passes when rubbed with oil.

146. _Cotton Seed Blue._

Cotton seed oil is bleached by treatment with either carbonate of soda
or caustic lime. In both cases, a considerable residue is left after
drawing off the bleached oil. This residue is treated with sulphuric
acid, and distilled at a high temperature, when there is left a compact
mass of a deep greenish-blue colour. On further treatment of this mass
with strong sulphuric acid, the green tint disappears, and a very
intense pure blue colour is produced. The blue mass is a mixture of the
coloured substance with some sulphuric acid, sulphate of soda, and fats.
The two former may be removed by washing with water; the latter by
treatment with naptha. Alcohol now dissolves the blue colour, and water
precipitates it from the solution chemically pure.

This blue has not been introduced as a pigment; and of its permanence,
and other attributes, we know nothing.

147. _Gold Blue._

Gold purple, under the name of Purple of Cassius, was once very well
known: a like compound of tin and gold may be made to yield a blue.
Resembling indigo, the colour is not remarkably brilliant, and, unless
several precautions are carefully observed, is rather violet than blue.
When obtained, the colour must be quickly washed by decantation, or it
changes first to violet and then to purple. Its costliness, lack of
brightness, and tendency to redden, are against its employment on the
palette. In enamelling it would doubtless preserve its colour, and in
exceptional cases might be useful.

148. _Iodine Blue._

It is curious that iodine, which gives a yellow with lead, should also
afford a blue with the same metal. When a solution of iodine in aqueous
soda (carbonate of soda is not so good) is added to nitrate or acetate
of lead-oxide, a transient violet-red precipitate falls, which
decomposes spontaneously under water, yielding iodine and a beautiful
blue powder. The colour, however, is exceedingly fugitive, even the
carbonic acid of the air separating iodine from it and forming a lead
salt. Bearing in mind the scarlet iodide of mercury, iodine is capable
of furnishing the three primary colours, distinguished alike by their
brilliancy and fugacity.

149. _Iridium Blue._

The rare metal iridium affords a blue which is a mixture of the oxide
and the sesquioxide. But being slightly soluble in water and
decolourised by sulphuretted hydrogen, it would not, other
considerations apart, be an acquisition.

150. _Manganese Blue._

An aqueous solution of permanganate of potash yields with baryta-water a
violet mixture, which afterwards becomes colourless, and deposits a blue
precipitate. This retains its colour after washing and drying, but
cannot be recommended as a pigment, being liable to suffer in contact
with organic substances, which deoxidize and decolourize the manganates
and permanganates.

151. _Platinum Blue._

With mercurous nitrate, the platinocyanide of potassium forms a thick
smalt blue, and the platinidcyanide a dark blue precipitate. The
compound is a mixture of platino- or platinidcyanide of mercury and
mercurous nitrate. Upon the presence of the latter the colour seems to
depend, for on washing with cold water containing nitric acid, the
nitrate is not removed nor the blue affected; but boiling water extracts
the nitrate and leaves a white residue. A blue containing mercurous
nitrate must necessarily be injured by impure air, and be otherwise
objectionable.

152. _Tungsten Blue_

is an oxide formed by the action of various deoxidizing agents on
tungstic acid. It remains unaltered in the air at ordinary temperatures,
is opaque, and of a blackish indigo-blue colour. As a pigment, there is
little to recommend it.

153. _Wood-Tar Blue._

The colours obtained from coal-tar have become household words, and it
is not impossible that those from wood-tar may be some day equally
familiar. At present wood-tar is comparatively unexplored, but the fact
that picamar furnishes a blue is at least as suggestive and hopeful as
that transient purple colouration by which aniline was once chiefly
distinguished. As aniline is a product of coal-tar, so picamar is a
product of wood-tar; and as the former gives a purple with
hypochlorites, so the latter yields a blue with baryta-water. Both are
distinguished by coloured tests, but there is this advantage in the
picamar blue--it is comparatively permanent.

Picamar blue is produced when a few drops of baryta-water are added to
an alcoholic solution of impure picamar, or even to wood-tar oil
deprived of its acid. The liquor instantly assumes a bright blue tint,
which in a few minutes passes into an indigo colour. From [Greek: pitta]
pitch, and [Greek: kallos] ornament, the blue is named _Pittacal_.

The mode of separating pittacal has not been clearly described. Dumas
states, that when precipitated in a flocculent state from its solutions,
or obtained by evaporation, it closely resembles indigo, and, like it,
acquires a coppery hue when rubbed. It is inodorous, tasteless, and not
volatile; and is abundantly soluble in acetic acid, forming a red
liquid, which, when saturated by an alkali, becomes of a bright blue. It
is represented as a more delicate test of acid and alkalis than litmus.
With acetate of lead, protochloride of tin, ammonio-sulphate of copper,
and acetate of alumina, it yields a fine blue colour with a tint of
violet, said not to be affected by air or light, and therefore
recommended for dyeing.

Like indigo, pittacal is believed to contain nitrogen, but its ultimate
composition has not been accurately determined. Dumas considers it
identical with a blue product obtained in 1827 from coal-tar by MM.
Barthe and Laurent. If this be the case, its greater stability over
coal-tar blues and colours generally admits of doubt. That, however, has
yet to be ascertained. Our object in noticing this blue has been
two-fold: first, to direct attention to wood-tar as a possible source of
colour; and secondly, to point to pittacal as a possible substitute for
indigo, possessing greater durability.

154. _Zinc-Cobalt Blue._

Cobalt, as furnishing a blue colour, is usually associated with alumina,
silica, or tin; and, as furnishing a green colour, with zinc. But there
is obtainable a compound of zinc and cobalt which gives a blue not only
free from green, but inclining rather to red. It is made by adding to a
solution of ordinary phosphate of soda in excess a solution first of
sulphate of zinc and then of sulphate of cobalt, and washing and
igniting the precipitate. The result is a vitreous blue with a purple
cast, of little body, and exceedingly difficult to grind. Altogether, it
is not unlike smalt, over which it has no advantages as an artistic
pigment either in colour or permanence. For tinting porcelain, however,
it is admirably adapted, imparting thereto a very pure dark blue of
extraordinary beauty. This blue is distinguished from smalt by
dissolving in acetic acid.

       *       *       *       *       *

Compared with the wide range of yellows, or even with reds, the artist
finds the number of his blues limited. The perfect native and excellent
artificial ultramarines, the good blues of cobalt, the fair Prussian
blue, and the doubtful indigo, are the four varieties he has for years
been in the habit of using, and is still mainly dependent on. Our
division, therefore, into permanent, semi-stable, and fugitive, is
easily effected.

In the front rank, pre-eminent among blues as among pigments generally,
stands genuine ultramarine. Behind it, are the artificial ultramarines;
and behind them again, cobalt and cerulian blue. To a greater or less
extent, all these are durable.

Among the semi-stable, must be classed cyanine or Leitch's blue, smalt,
and Prussian blue.

To the fugitive, belong indigo and the somewhat more permanent intense
blue, Antwerp blue, and the copper blues.

In this list of blues, which grace or disgrace the palette of the
present day, there is one colour which, although not permanent, is
almost indispensable. As yet, the chemist cannot in all cases lay down
the law as to what pigments may or may not be employed. The painter who
unnecessarily uses fugitive colours must have little love for his
craft, and a poor opinion of the value of his work; but, even with the
best intentions and the utmost self-esteem, the artist cannot always
confine himself to strictly stable pigments. He has no right to use
orpiment instead of cadmium yellow, or red lead instead of vermilion, or
copper blue instead of cobalt: he has no business to employ indigo when
Prussian blue saddened by black will answer his purpose; but--what
pigment can he substitute for Prussian blue itself? None. In its
wondrous depth, richness, and transparency, it stands alone: there is no
yellow to compare with it, no red to equal it, no blue to rival it. In
force and power it is a colour among colours, and transparent beyond
them all. The great importance of transparent pigments is to unite with
solid or opaque colours of their own hues, giving tone and atmosphere
generally, together with beauty and life; to convert primary into
secondary, and secondary into tertiary colours, with brilliancy; to
deepen and enrich dark colours and shadows, and to impart force and tone
to black itself. For such effects, no pigment can vie with Prussian
blue. What purples it produces, what greens it gives, what a matchless
range of grays; what velvety glow it confers, how it softens the
harshness of colours, and how it subdues their glare. No; until the
advent of a perfect palette, the artist can scarcely part with his
Prussian blue; nor can the chemist, who has nothing better to offer,
hold him to blame. It is for Art to copy Nature with the best materials
she possesses: it is for Science to learn the secrets of Nature, and
turn them to the benefit of Art.




CHAPTER XI.

ON THE SECONDARY, ORANGE.


Orange is the first of the secondary colours in relation to light, being
in all the variety of its hues composed of _yellow_ and _red_. A true or
perfect orange is such a compound of red and yellow as will neutralize a
perfect blue in equal quantity either of surface or intensity; and the
proportions of such compound are five of perfect red to three of perfect
yellow. When orange inclines to red, it takes the names of _scarlet_,
_poppy_, &c.: in gold colour, &c., it leans towards yellow. Combined
with green it forms the tertiary _citrine_, and with purple the tertiary
_russet_: it also furnishes a series of warm semi-neutral colours with
black, and harmonizes in contact and variety of tints with white.

Orange is an advancing colour in painting:--in nature it is effective at
a great distance, acting powerfully on the eye, diminishing its
sensibility in accordance with the strength of the light in which it is
viewed. It is of the hue, and partakes of the vividness of sunshine, as
it likewise does of all the powers of its components, red and yellow.
Pre-eminently a _warm_ colour, being the equal contrast of or antagonist
to blue, to which the attribute of _coolness_ peculiarly belongs, it is
discordant when standing alone with yellow or with red, unresolved by
their proper contrasts or harmonizing colours, purple and green. As an
archeus or ruling colour, orange is one of the most agreeable keys in
toning a picture, from the richness and warmth of its effects. If it
predominate therein, for the colouring to be true, the violet and purple
should be more or less red, the red more or less scarlet, the yellow
more or less intense and orange, and the orange itself be intense and
vivid. Further, the greens must lose some of their blue and consequently
become yellower, the light blues be more or less light grey, and the
deep indigo more or less marrone.

Although the secondary colours are capable of being obtained by
admixture of the primaries in an infinitude of hues, tints, and shades;
yet simple original pigments of whatever class--whether secondary,
tertiary, or semi-neutral--are, it has been said before, often superior
to those compounded, both in a chemical and artistic sense. Hence a
thoroughly good original orange is only of less value and importance
than a thoroughly good original yellow, a green than a blue, or a
purple than a red. To produce pure and permanent compound hues requires
practice and knowledge, and we too often see in the works of painters
combinations neither pleasing nor stable. Colours are associated with
each other which do not mix kindly, and compounds formed of which one or
both constituents are fugitive. As a consequence, mixed tints are
frequently wanting in clearness, and, where they do not disappear
altogether, resolve themselves into some primary colour; orange becoming
red by a fading of the yellow, green yellow by a fading of the blue, and
purple blue by a fading of the red. Again, with regard to compound
tints, there is the danger of one colour reacting upon and injuring
another, as in the case of greens obtained from chrome yellow and
Prussian blue, where the former ultimately destroys the latter. Of
course a mixture of two permanent pigments which do not react on each
other will remain permanent; the green, for instance, furnished by
aureolin and native ultramarine lasting as long as the ground itself. To
produce, however, the effects desired, the artist does not always stop
to consider the fitness and stability of his colours in compounding,
even if he possess the needed acquaintance with their physical and
chemical properties. At all times, therefore, but especially when such
knowledge is slight, good orange, &c., pigments are of more or less
value, as by their use the employment of inferior mixtures is to a great
extent avoided. In mingling primary with primary, if one colour does not
compound well with the other, or is fugacious, the result is failure;
but a secondary is not so easily affected by admixture: a green, for
example, is seldom quite ruined by the injudicious addition of blue or
yellow; and even if either of the latter be fugitive, the green will
remain a green if originally durable. Thus the secondaries, if they are
not already of the colour required, may be brightened or subdued,
deepened or paled, with comparative impunity. The artist who, from long
years of experience, knows exactly the properties and capabilities of
the colours he employs, may in a measure dispense with secondary
pigments, and obtain from the primaries mixed tints at once stable,
beautiful, and pure; but even he must sometimes resort to them, as when
a green like emerald or viridian is required, which no mixture of blue
and yellow will afford. The primaries, by reason of their not being able
to be composed of other colours, occupy the first place on the palette,
and are of the first importance; but the secondaries are far too useful
to be disregarded, and have a value of their own, which both veteran and
tyro have cause to acknowledge.

The list of original orange pigments was once so deficient, that in some
old treatises on the subject of colours, they are not even mentioned.
This may have arisen, not merely from their paucity, but from the
unsettled signification of the term orange, as well as from improperly
calling these pigments reds, yellows, &c. In these days, however, orange
pigments are sufficiently numerous to merit a chapter to themselves;
they indeed comprise some of the best colours on the palette.

155. BURNT SIENNA,

or _Burnt Terra di Sienna_, is calcined raw Sienna, of a rich
transparent brown-orange or orange-russet colour, richer, deeper, and
more transparent than the raw earth. It also works and dries better, has
in other respects the qualities of its parent colour, and is a most
permanent and serviceable pigment in painting generally. For the warm
tints in rocks, mud banks, and buildings, this colour is excellent. When
mixed with blue it makes a good green; furnishing a bright green with
cobalt, and one much more intense with Prussian blue. For the foresea,
whether calm or broken by waves, it may be employed with a little
madder; while compounded with a small portion of the latter and lamp
black, it meets the hues of old posts, boats, and a variety of near
objects, as the tints may be varied by modifying the proportions of the
component colours. Used with white, it yields a range of sunny tones;
and with aureolin or French blue and aureolin will be found of service,
the last compound giving a fine olive green. Similar but fugitive greens
are afforded by admixture of burnt Sienna with indigo and yellow or
Roman ochre, or raw Sienna; tints which may be saddened into olive
neutrals by the addition of sepia, and rendered more durable by
substituting for indigo Prussian blue and black. Mixed with viridian, it
furnishes autumnal hues of the utmost richness, beauty, and permanence;
and, alone, is valuable as a glaze over foliage and herbage. For the
dark markings and divisions of stones a compound of Payne's gray and
burnt Sienna will prove serviceable; while for red sails the Sienna,
either by itself, with brown madder, or with Indian red, cannot be
surpassed. For foregrounds, banks and roads, cattle and animals in
general, burnt Sienna is equally eligible, both alone and compounded. It
has a slight tendency to darken by time.

156. CADMIUM ORANGE

was first introduced to the art-world at the International Exhibition of
1862, where it was universally admired for its extreme brilliancy and
beauty, a brilliancy equalled by few of the colours with which it was
associated, and a beauty devoid of coarseness. We remember well the
power it possessed of attracting the eye from a distance; and how, on
near approach, it threw nearly all other pigments into the shade. It has
in truth a lustrous luminosity not often to be met with, added to a
total absence of rankness or harshness. A simple original colour,
containing no base but cadmium, it is of perfect permanence, being
uninjured by exposure to light, air or damp, by sulphuretted hydrogen,
or by admixture. Having in common with cadmium sulphides a certain
amount of transparency, it is invaluable for gorgeous sunsets and the
like, either alone or compounded with aureolin. Of great depth and power
in its full touches, the pale washes are marked by that clearness and
delicacy which are so essential in painting skies. As day declines, and
blue melts into green, green into orange, and orange into purple, the
proper use of this pigment will produce effects both glowing and
transparent. Transparency signifies the quality of being seen through or
into; and in no better way can it be arrived at than by giving a number
of thin washes of determined character, each lighter than the preceding
one. With due care in preserving their forms, from the commencement to
the termination, such washes of orange will furnish hues the softest and
most aerial. For bits of bright drapery, a glaze over autumn leaves, and
mural decoration, this colour is adapted; while in illumination it
supplies a want formerly much felt. "With the exception of scarlet or
bright orange," said Mr. Bradley, nine or ten years since, in his Manual
of Illumination, "our colours are everything we could wish." As an
original pigment, a permanent scarlet does not yet exist; but the
brilliancy of cadmium orange cannot be disputed, nor its claim to be the
only unexceptionable bright orange known. It even assists the formation
of the other colour: remarks the author mentioned, "Brilliancy is
obtained by gradation. Suppose a scarlet over-curling leaf, for example.
The whole should be painted in pure orange, with the gentlest possible
after-touch of vermilion towards the corner under the curl. When dry, a
firm line--not wash--of carmine, (of madder, preferable.--_Ed._), passed
within the outline on the shade side only of the leaf, will give to the
whole the look of a bright scarlet surface, but with an indescribable
superadded charm, that no merely flat colour can possess." In the same
branch of art, illumination, cadmium orange, opposed to viridian,
presents a most dazzling contrast, especially if relieved by purple.

157. CHINESE ORANGE

belongs to the coal-tar colours, and ought strictly to have been classed
therewith. We have preferred, however, to keep it separate, because, as
Chinese Orange, it was introduced as a pigment, and has not been
employed as a dye. In colour, it somewhat resembles burnt Sienna,
enriched, reddened, brightened, and made more transparent, by admixture
with crimson lake. From its behaviour, it would seem to be composed of
yellow and red, such a compound as magenta and aniline yellow would
afford. Its pale washes are uncertain, being apt to resolve themselves
into red and yellow, of which the latter appears the most permanent;
for, on exposure to light and air, the red more or less flies, leaving
here a yellow, and there a reddish-yellow ground: in places both red and
yellow disappear. Like all fugitive colours, it is comparatively stable
when used in body; but even then it entirely loses its depth and
richness, and in a great measure its redness, becoming faded and
yellowish. In thin washes or glazing it is totally inadmissible; and,
being neither a red, an orange, nor a brown, is unsuited to pure
effects. Nevertheless, where it need not be unduly exposed; in portfolio
illuminations, for instance, the richness, subdued brilliancy, and
transparency of this pigment, justify its adoption. It is not affected
by an impure atmosphere.

Aniline colours may be adapted for oil painting by dissolving them in
the strongest alcohol, saturating the solution with Dammar resin,
filtering the tincture, and pouring the filtrate either on pure water or
solution of common salt, stirring well all the time. The water or brine
solution must be at least twenty times the bulk of the tincture. The
colour after being collected on a filter, washed, and dried, can be
ground with linseed oil, poppy oil, or oil varnishes.

158. CHROME ORANGE,

_Orange Chrome_, or _Orange Chromate of Lead_, is a sub-chromate of lead
of an orange-yellow colour, produced by the action of an alkali on
chrome yellow. Like all the chromates of lead, it is characterized by
power and brilliancy; but also by a rankness of tone, a want of
permanence, and a tendency to injure organic pigments. By reason of its
lead base it is subject to alteration by impure air, but is on the whole
preferable to the chrome yellows, being liable in a somewhat less degree
to their changes and affinities. As, however, a colour has no business
to be used if a better can be procured, the recent introduction of
cadmium orange renders all risk unnecessary.

159. MARS ORANGE,

_Orange de Mars_, is a subdued orange of the burnt Sienna class, but
without the brown tinge that distinguishes the latter. Marked by a
special clearness and purity of tone, with much transparency, it affords
bright sunny tints in its pale washes, and combines effectively with
white. Being an artificial iron ochre it is more chemically active than
native ochres, and needs to be cautiously employed with pigments
affected by iron, such as the lakes of cochineal and intense blue.

160. MIXED ORANGE.

Orange being a compound colour, the place of original orange pigments
can be supplied by mixtures of yellow and red; either by glazing one
over the other, by stippling, or by other modes of breaking and
intermixing them, according to the nature of the work and the effect
required. For reasons lately given, mixed pigments are apt to be
inferior to the simple or homogeneous both in colour, working, and other
properties; yet some pigments mix and combine more cordially and with
better results than others; as is the case with liquid rubiate and
gamboge. Generally speaking, the compounding of colours is easier in oil
than in water; but in both vehicles trouble will be saved by beginning
with the predominating colour, and adding the other or others to it.

Perhaps in this, our first chapter on the secondary colours, and
consequently on colours that can be compounded, a few remarks on mixed
tints from a chemical point of view will not be deemed superfluous.

There are two ways, we take it, of looking at a picture--from a purely
chemical, and from a purely artistic, point of view. Regarded in the
first light, it matters little whether a painting be a work of genius or
a daub, provided the pigments employed on it are good and properly
compounded. The effects produced are lost sight of in a consideration of
the materials, their permanence, fugacity, and conduct towards each
other. Painting is essentially a chemical operation: with his pigments
for reagents, the artist unwittingly performs reaction after reaction,
not with the immediate results indeed of the chemist in his laboratory,
but often as surely. As colour is added to colour, and mixture to
mixture, acid meets alkali, metal animal, mineral vegetable, inorganic
organic. With so close a union of opposite and opposing elements, the
wonder is not so much that pictures sometimes perish, but that they ever
live. It behoves the artist, then, not only to procure the best and most
permanent pigments possible, but to compound them in such a manner that
his mixed tints may be durable as well as beautiful. To effect or aid in
effecting this, although he may not always be able to act upon them, the
following axioms should be borne in mind:--

1. If they do not react on each other, a permanent pigment added to a
permanent pigment yields a permanent mixture.

2. If they do react on each other, a permanent pigment added to a
permanent pigment yields a semi-stable or fugitive mixture.

3. A permanent pigment added to a semi-stable pigment yields a
semi-stable mixture.

4. A permanent pigment added to a fugitive pigment yields a fugitive
mixture.

Consequently--

5. A permanent pigment may be rendered fugitive or semi-stable by
improper compounding.

6. A semi-stable or fugitive pigment is not rendered durable by being
compounded.

7. As a chain is only as strong as its weakest link, so a mixture is
only as permanent as its least durable constituent.

To give illustrations--

1. Ultramarine added to Chinese white yields a permanent mixture.

2. Ultramarine added to an acid constant white yields a semi-stable or
fugitive mixture.

3. Ultramarine added to Prussian blue yields a semi-stable mixture.

4. Ultramarine added to indigo yields a fugitive mixture.

Except in the second instance, where the blue is either partially or
wholly destroyed--in time, be it remembered, not at once--according to
the quantity and strength of the acid in the white, the ultramarine
remains unchanged. Hence at first sight our third and fourth conclusions
may appear wrong; inasmuch as, it may be argued, a blue mixture cannot
be semi-stable or fugitive when blue is left. To this we reply, unless
both constituents are fugitive, a mixture will always more or less
possess colour; but, if even one constituent be semi-stable or fugitive,
a mixture will slowly but surely lose _the_ colour for which it was
compounded, and be _as a mixture_ semi-stable or fugitive.

It need hardly be observed that the number of permanent orange, green,
and purple hues which the artist can compound, depends mainly on the
number of permanent yellows, reds, and blues at his disposal. In mixed
orange, therefore, a selection of durable yellows and reds is of the
first importance. It should, however, be remarked that mixed orange,
more sober and less decided, is obtainable by the use of citrine and
russet; in the former of which yellow predominates, and in the latter,
red: consequently orange results when yellow is added to russet, red to
citrine, or citrine to russet.

    PERMANENT YELLOWS.     | PERMANENT REDS.
                           |
    Aureolin.              | Cadmium Red.
    Cadmium, deep.         | Liquid Rubiate.
    Cadmium, pale.         | Madder Carmine.
    Lemon Yellow.          | Rose Madder.
    Mars Yellow.           | Mars Red.
    Naples Yellow, modern. | Ochres.
    Ochres.                | Vermilions.
    Orient Yellow.         |
    Raw Sienna.            |

None of these pigments react on each other, and from them can be
produced the most durable mixed orange that yellow and red will afford.

161. NEUTRAL ORANGE,

or _Penley's Neutral Orange_, is a permanent compound pigment composed
of yellow ochre and the russet-marrone known as brown madder: it is
chiefly valuable in water-colour. Paper, being white, is too opaque to
paint upon, without some wash of colour being first passed over it;
otherwise the light tones of the sky are apt to look crude and harsh. It
must, therefore, be gone over with some desirable tint, that shall
break, in a slight degree, the extreme brilliancy of the mere paper. For
this purpose, a thin wash of the orange is to be put over the whole
surface of the paper with a large flat brush, care being taken never to
drive the colour too bare, _i.e._ never to empty the brush too closely,
but always to replenish before more is actually required. This first
wash of colour not only gives a tone to the paper, but secures the
pencil sketch from being rubbed out.

The reason why, in this compound, yellow ochre, as a yellow, is
preferred to any of the others, is, that it is a broken yellow, that is,
a yellow slightly altered by having another hue, such as red, or brown,
in its composition. It is somewhat opaque too, and hence, from this
quality, is especially adapted for distances. Brown madder also is a
subdued red, which, when in combination with the former, produces a
neutral orange, partaking of the character of soft light. As a general
rule, yellow ochre is to predominate in broad daylight, and brown madder
in that which is more sombre and imperfect: hence the pigment can be
yellowed or reddened, by the addition of one or the other. For a clear
sunset, the neutral orange must be repeated, with a preponderance of
ochre at the top, assisted by a little cadmium yellow near the sun; the
madder being added downwards.

In treating of distant mountains, a distinction is to be made between
them and the clouds, the former requiring solidity, while the latter are
only to be regarded as vapour and air. Mountains, being opaque bodies,
are acted upon by atmosphere more or less, according to their position,
their distance, and the state of the weather. To express this
distinction, recourse must be had to an under tint, except where the
tone is decidedly blue--an uncommon case. No mixture can give this with
such truth as the neutral orange. A wash, therefore, should be passed
over the mountains, with nearly all yellow in the high lights, or in the
gleams of sunshine, and, on the contrary, almost all brown madder for
the shadows. These two degrees of tone must be run into each other
while the drawing is wet. A beautiful and soft under tone will thus be
given to receive the greys.

162. ORANGE, OR BURNT ROMAN OCHRE,

called also _Spanish Ochre_, is a very bright yellow or Roman ochre
burnt, by which operation it acquires warmth, colour, transparency, and
depth. Moderately bright, it forms good flesh tints with white, dries
and works well both in water and oil, and is a very good and eligible
pigment. It may be used in enamel painting, and has all the properties
of its original ochre in other respects.

A redder hue is imparted by mixing the ochre with powdered nitre before
ignition, the orange red being subsequently washed with hot water.

       *       *       *       *       *

163. _Anotta_,

Annotto, Annatto, Arnotto, Arnotta, Terra Orellana, Rocou, &c., is met
with in commerce under the names of cake anotta, and flag or roll
anotta. The former, which comes almost exclusively from Cayenne, should
be of a bright yellow colour: the latter, which is imported from the
Brazils, is brown outside and red within. It is prepared from the pods
of the _bixa orellana_, and appears generally to contain two colouring
matters, a yellow and a red, which are apt to adhere to each other and
produce orange. Anotta dissolves with difficulty in water, but readily
in alcohol and alkaline solutions, from which last it may be thrown down
as a lake by means of alum. Being, however, exceedingly fugitive and
changeable, it is not fit for painting; but is chiefly employed in
dyeing silk, and colouring varnishes and cheese. Very red cheese should
be looked upon with suspicion, for although the admixture of anotta is
in no way detrimental to health provided the drug be pure, it is
commonly adulterated with red lead and ochre. Several instances are on
record that Gloucester and other cheeses have been found contaminated
with red lead, through having been coloured with anotta containing it,
and that this contamination has produced serious consequences.

_Bixine_ is a purified extract of anotta made in France, and used by
dyers.

164. _Antimony Orange_,

Golden Sulphur of Antimony, or Golden Yellow, is a hydro-sulphuret of
antimony of an orange colour, which is destroyed by the action of strong
light. It is a bad dryer in oil, injurious to many pigments, and in no
respect eligible either in water or oil.

165. _Chromate of Mercury_

has been improperly classed as a red with vermilion, for though it is of
a bright ochrous red in powder, when ground it becomes a bright
ochre-orange, and affords with white very pure orange tints.
Nevertheless it is a bad pigment, since light soon changes it to a deep
russet colour, and foul air reduces it to extreme blackness.

166. _Damonico_,

or Monicon, is an iron ochre, being a compound of raw Sienna and Roman
ochre burnt, and having all their qualities. It is rather more russet in
hue than the pigment known as orange or burnt Roman ochre, has
considerable transparency, is rich and durable in colour, and furnishes
good flesh tints. As in orange ochre, powdered nitre may be employed in
its preparation. Notwithstanding its merits, it is obsolete or nearly
so; doubtless because burnt Sienna mixed with burnt Roman ochre
sufficiently answers the purpose.

167. _Gamboge Orange._

On adding acetate of lead to a potash solution of gamboge, a rich bright
orange is precipitated, which may be washed on a filter till the
washings are colourless, and preserves its hue with careful drying. The
orange which we thus obtained stood well in a book, but it cannot be
recommended as an artistic pigment. Perhaps in dyeing, the lead and
gamboge solutions might be worth a trial.

168. _Laque Minérale_

is a French pigment, a species of chromic orange, similar to the orange
chromate of lead. This name is likewise given to orange oxide of iron.

169. _Madder Orange_,

or Orange Lake. It has been said that the yellows so-called produced
from madder are not remarkable for stability, differing therein from the
reds, purples, russets, and browns. Like them, this 'orange' is of
doubtful colour and permanence, and not to be met with, brilliant and
pure, on the palette of to-day. The russet known as Rubens' madder has a
tendency to orange.

170. _Orange Lead_,

of a dull orange colour, is an orange protoxide of lead or massicot.
Like litharge, it may be employed in the preparation of drying oils,
and, being a better drier than white lead, may be substituted for it in
mixing with pigments which need a siccative, as the bituminous earths.

Minium sometimes leans to orange; and there is made from ceruse a
peculiar red, _Mineral Orange_.


_Orange Orpiment_,

or Realgar, has also been called Red Orpiment, improperly, since it is
a brilliant orange, inclining to yellow. There are two kinds, a native
and an artificial, of which the former is the _sandarac_ of the
ancients, and is rather redder than the latter. They possess the same
qualities as pigments, and as such resemble yellow orpiment, to which
the old painters gave the orange hue by heat, naming it alchemy and
burnt orpiment. Orange orpiment contains more arsenic and less sulphur
than the yellow, and is of course highly poisonous. It is often
sophisticated with brickdust and yellow ochre.

172. _Thallium Orange_

is produced when bichromate of potash is added to a neutral salt of the
protoxide of thallium, as an orange-yellow precipitate. The scarcity of
the metal precludes their present introduction as pigments, but if the
chromates of thallium were found to resist the action of light and air,
and not to become green by deoxidation of the chromic acid, they might
possibly prove fitted for the palette. It is a question whether their
_very_ slight solubility in water would be a fatal objection; and,
although they would be liable to suffer from a foul atmosphere, we are
inclined to think the effects would not be so lasting as in the
chromates of lead. Like lead sulphide, the sulphide of thallium ranges
from brown to brownish-black, or grey-black; and, like it too, is
subject to oxidation and consequent conversion into colourless sulphate.
It is, however, much more readily oxidized than sulphate of lead; and
hence the thallium chromates would doubtless soon regain their former
hue on exposure to a strong light.

Mr. Crookes, who discovered this new metal in 1861, believes that the
deep orange shade observable in some specimens of sulphide of cadmium is
due to the presence of thallium. He has frequently found it, he says, in
the dark-coloured varieties, and considers the variations of colour in
cadmium sulphide to be owing to traces of thallium. That thallium
affects the colour is most probable, but it is not necessarily the cause
of the orange hue. The tint of cadmium sulphide is a mere matter of
manufacture, seeing that from the same sample of metal there can be
obtained lemon-yellow, pale yellow, deep yellow, orange-yellow, and
orange-red. With deference to the opinion of a chemist so distinguished,
we hold that thallium rather impairs the beauty of cadmium sulphide than
imparts to it an orange shade, the thallium being likewise in the form
of sulphide, and therefore more or less black. On chromate of cadmium,
made with bichromate of potash, thallium would naturally confer an
orange hue.

173. _Uranium Orange_

is obtainable by wet and dry methods as a yellowish-red, or, when
reduced to powder, an orange-yellow, uranate of baryta. It is an
expensive preparation, superfluous as a pigment.

174. _Zinc Orange._

When hydrochloric acid and zinc are made to act on nitro-prusside of
sodium, a corresponding zinc compound is formed of a deep orange colour,
slightly soluble in water, and not permanent.

       *       *       *       *       *

For a secondary colour, orange is well represented on the modern
palette, and can point to some pigments as good and durable as any to be
found among the primaries. Burnt Sienna, cadmium orange, Mars orange,
neutral orange, and orange or burnt Roman ochre, are all strictly
permanent. The so-called orange vermilions were, it will be remembered,
classed among the reds.

As semi-stable, must be ranked chrome orange; and as fugitive, Chinese
orange, orange orpiment, and orange lead.

From the foregoing division, the predominance of eligible orange
pigments over those less trustworthy is manifest. Unfortunately, with
many painters it is not so manifest that their secondary and compound
colours should receive as much attention as the primaries, and that it
is their duty, not only to the art which they practice, but to the
patrons for whom they practice it, that their orange and green and
purple hues, should be as durable as their yellows, reds, and blues. For
such, the introduction of a new permanent pigment is of little interest,
unless its colour be primary; so wedded are they to that passion for
compounding which the chemist views with dismay. With dismay, because he
knows that the rules of mixture are severe, and cannot with impunity be
altered; that, although disguised in oil or gum, each pigment is a
chemical compound, with more or less of affinity and power, more or less
likely to act or be acted upon. Because he knows that, except with the
most experienced artists, compounding leads to confusion; and that in it
the temptations to use semi-stable or fugitive colours are strong. Look
at those tables of mixed tints of which artist-authors are so fond, and
tell us whether they always bear scrutiny--surely not. Admirable,
perfect as these tints may be in an artistic sense, how often is their
beauty like the hectic flush of consumption, which carries with it the
seeds of a certain death. Will that orange where Indian yellow figures
ever see old age, or that green with indigo, or purple with cochineal
lake? Will they not rather spread over the picture the Upas-tree of
fugacity, and kill it as they die themselves!




CHAPTER XII.

ON THE SECONDARY, GREEN.


Green, which occupies the middle station in the natural scale of colours
and in relation to light and shade, is the second of the secondary
colours. It is composed of the extreme primaries, _yellow_ and _blue_,
and is most perfect in hue when constituted in the proportions of three
of yellow to eight of blue of equal intensities; because such a green
will exactly neutralize and contrast a perfect red in the ratio of
eleven to five, either of space or power. Of all compound colours, green
is the most effective, distinct, and striking, causing surprise and
delight when first produced by a mixture of blue and yellow, so
dissimilar to its constituents does it appear to the untutored eye.
Compounded with orange, green converts it into the one extreme tertiary
_citrine_; while mixed with purple, it becomes the other extreme
tertiary _olive_: hence its relations and accordances are more general,
and its contrasts more agreeable with all colours, than those of any
other individual colour. Accordingly it has been adopted very wisely in
nature as the common garb of the vegetal creation. It is, indeed, in
every respect a central or medial colour, being the contrast,
compensatory in the proportion of eleven to five, of the middle primary
_red_, on the one hand, and of the middle tertiary _russet_, on the
other; while, unlike the other secondaries, all its hues, whether
tending to blue or yellow, are of the same denomination.

These attributes of green, which render it so universally effective in
contrasting colours, cause it also to become the least useful in
compounding them, and the most apt to defile other colours in mixture.
Nevertheless it forms valuable semi-neutrals of the olive class with
_black_, for of such subdued tones are those greens by which the more
vivid tints of nature are opposed. Accordingly, the various greens of
foliage are always more or less semi-neutral in hue. As green is the
most general colour of vegetal nature and principal in foliage; so red,
its harmonizing colour, with compounds of red, is most general and
principal in flowers. Purple flowers are commonly contrasted with
centres or variegations of bright yellow, as blue flowers are with like
relievings of orange; and there is a prevailing hue, or character, in
the green colour of the foliage of almost every plant, by which it is
harmonized with the colours of its flowers.

The chief discord of green is blue; and when they approximate or
accompany each other, they require to be resolved by the opposition of
warm colours. It is in this way that the warmth of distance and the
horizon reconciles the azure of the sky with the greenness of a
landscape. Its less powerful discord is yellow, which needs to be
similarly resolved by a purple-red, or its principles. In tone, green is
cool or warm, sedate or gay, either as it inclines to blue or to yellow;
yet in its general effects it is cool, calm, temperate, and refreshing.
Having little power in reflecting light, it is a retiring colour, and
readily subdued by distance: for the same reason, it excites the retina
less than most colours, and is cool and grateful to the eye. As a colour
individually, green is eminently beautiful and agreeable, but it is more
particularly so when contrasted by its compensating colour, red, as it
often is in nature, even in the green leaves and young shoots of plants
and trees. "The autumn only is called the painter's season," remarks
Constable, "from the great richness of the colours of the dead and
decaying foliage, and the peculiar tone and beauty of the skies; but the
spring has, perhaps, more than an equal claim to his notice and
admiration, and from causes not wholly dissimilar,--the great variety of
tints and colours of the living foliage, accompanied by their flowers
and blossoms. The beautiful and tender hues of the young leaves and
buds are rendered more lovely by being contrasted, as they now are, with
the sober russet browns of the stems from which they shoot, and which
still show the drear remains of the season that is past."

The number of pigments of any colour is in general proportioned to its
importance; hence the variety of greens is very great, though the
classes of those in common use are not very numerous. Of the three
secondaries, green is the colour most often met with, and, consequently,
the most often compounded: for this last reason, perhaps, the palette is
somewhat deficient in really good original greens--more deficient than
there is any necessity for.


CHROME OXIDES.

By numerous methods both wet and dry, oxides of chromium are obtainable
pale and deep, bright and subdued, warm and cool, opaque and
transparent: sometimes hydrated, in which case they cannot be employed
in enamelling; and sometimes anhydrous, when they are admissible
therein. But whatever their properties may be, chemical, physical, or
artistic, they are all strictly stable. Neither giving nor receiving
injury by admixture, equally unaffected by foul gas and exposure to
light, air, or damp, these oxides are perfectly unexceptionable in every
respect. For the most part they are eligible in water and oil, drying
well in the latter vehicle, and requiring in the former much gum. They
have long been known as affording pure, natural, and durable tints; but,
until within the last few years, have been rather fine than brilliant
greens. Lately, however, processes have been devised, yielding them
almost as bright, rich, and transparent, as the carmine of cochineal
itself.

175. OXIDE OF CHROMIUM,

_Opaque Oxide of Chromium_, _Green Oxide of Chromium_, _Chrome Oxide_,
_True Chrome Green_, _Native Green_, _&c._, is found native in an impure
state as Chrome Ochre, but is always artificially prepared for artistic
use. Obtained anhydrous by dry modes, this is the only chrome oxide
available in enamelling, and is the one seen on superior porcelain. It
is a cold, sober sage green, deep-toned, opaque, and, although dull,
agreeable to the eye. Its tints with white are peculiarly delicate and
pleasing, possessing a silvery luminous quality, and giving the effect
of atmosphere. Being very dense and powerful, it must be employed with
care to avoid heaviness, and is preferably diluted with a large quantity
of white, or compounded with transparent yellow. In the hands of a
master, this gray-green furnishes lustrous hues with brown pink, Italian
pink, and Indian yellow; three beautiful but fugitive pigments, of
which the two last may be replaced by aureolin. Of this Mr. Penley
observes, "as adapted for the colouring of foliage and herbage, it is
impossible to say too much in its praise. It imparts the vividness and
freshness of nature to every colour with which it is combined;" and he
brackets oxide of chromium with aureolin as a compound hue "extremely
useful." In flat tints, the oxide sometimes does not wash well in water.

176. TRANSPARENT OXIDE OF CHROMIUM

being deficient in body, is only eligible in oil. A very pale
greyish-white green in powder, it gives an agreeable yellowish green of
some depth in oil, moderately bright, but not very pure or clear.

We are acquainted with another transparent chrome oxide of far greater
beauty, brightness, purity, and clearness than the above. Of a bluish
green hue, a difficulty in getting it to mix with oil renders it at
present unavailable.

177. VERONESE GREEN,

or _French Veronese Green_, is a comparatively recent introduction,
similar in colour and general properties to the following; beside which,
however, it appears dull, muddy, and impure. It is often adulterated
with arsenic to an enormous extent, which interferes with its
transparency, mars its beauty, and renders it of course rankly
poisonous.

178. VIRIDIAN

is a still later addition to the palette, and the only permanent green
which can be described as gorgeous, being not unlike the richest velvet.
Pure and clear as the emerald, it may be called the Prussian Blue of
Greens, of such richness, depth, and transparency is it. In hue of a
bluish-green, its deepest shades verge on black, while its light tints
are marked by transparent clearness unsurpassed. No compound of blue and
yellow will afford a green at once so beautiful and stable, so gifted
with the quality of light, and therefore so suited for aerial and liquid
effects. Used with aureolin, it gives foliage greens sparkling with
sunshine; and, fitly compounded, will be found invaluable for the glassy
liquidity of seas, in painting which it becomes incumbent to employ
pigments more or less transparent. "The general failing in the
representation of the sea is, that instead of appearing liquid and thin,
it is made to bear the semblance of opacity and solidity. In order to
convey the idea of transparency, some object is often placed floating on
the wave, so as to give reflection; and it is strange that we find our
greatest men having recourse to this stratagem. To say it is not true in
all cases, is saying too much; but this we do assert, that as a general
principle it is quite false, and we prove it in this way: water has its
motion, more or less, from the power of the wind; it is acted upon in
the mass, and thus divided into separate waves, and these individually
have their surface ruffled, which renders them incapable of receiving
reflection. The exception to this will be, where the heaving of the sea
is the result of some gone-by storm, when the wind is hushed, and the
surface becomes bright and glassy. In this state, reflections are
distinctly seen. Another exception will be in the hollow portion of the
waves, as they curl over, and dash upon the shore."

As viridian, like the sea, is naturally "liquid and thin, bright and
glassy," the extract we have quoted from Mr. Penley, points to this
green as a pigment peculiarly adapted for marine painting; in which, it
may be added, its perfect permanence and transparency will be
appreciated in glazing. Its fitness for foliage has been remarked; but
in draperies the colour will prove equally useful, and in illumination
will be found unrivalled. In the last branch of art, indeed, viridian
stands alone, not only through its soft rich brilliancy, but by the
glowing contrast it presents with other colours: employed as a ground,
it throws up the reds, &c., opposed to it, in a marvellous manner. Like
the three preceding oxides of chromium, viridian neither injures nor is
injured by other pigments; is unaffected by light, damp, or impure air;
and is admissible in fresco. In enamelling it cannot be used; the
colour, depending on the water of hydration, being destroyed by a strong
heat.


COPPER GREENS

are commercially known as _Emerald Green_, _Malachite Green_, _Scheele's
Green_, _Schweinfurt Green_, _Verdigris_, _Green Bice_, _Green
Verditer_, _Brunswick Green_, _Vienna Green_, _Hungary Green_, _Green
Lake_, _Mineral Green_, _Patent Green_, _Mountain Green_, _Marine
Green_, _Saxon Green_, _French Green_, _African Green_, _Persian Green_,
_Swedish Green_, _Olympian Green_, _Imperial Green_, _Mitis Green_,
_Pickle Green_, &c.

The general characteristics of these greens are brightness of colour,
well suited to the purposes of house-painting, but seldom adapted to the
modesty of nature in fine art; considerable permanence, except when
exposed to the action of damp and impure air, which ultimately blacken
most of them; and good body. They have a tendency to darken by time, dry
well as a rule in oil, and are all more or less poisonous, even those
not containing arsenic.

179. EMERALD GREEN,

_Schweinfurt Green_, _Vienna Green_, _Imperial Green_, _Brunswick
Green_, _Mitis Green_, &c., is a cupric aceto-arsenite, prepared on the
large scale by mixing arsenious acid with acetate of copper and water.
It differs from Scheele's Green, or cupric arsenite, in being lighter,
more vivid, and more opaque. Powerfully reflective of light, it is
perhaps the most durable pigment of its class, not sensibly affected by
damp nor by that amount of impure air to which pictures are usually
subject: indeed it may be ranked as permanent both in itself and when in
tint with white. It works better in water than in oil, in which latter
vehicle it dries with difficulty. Bearing the same relation to greens
generally as Pure Scarlet bears to reds, its vivid hue is almost beyond
the scale of other bright pigments, and immediately attracts the eye to
any part of a painting in which it may be employed. Too violent in
colour to be of much service, it has the effect, when properly placed,
of toning down at once, by force of contrast, all the other greens in a
picture. If discreetly used, it is occasionally of value in the drapery
of a foreground figure, where a bright green may be demanded; or in a
touch on a gaily painted boat or barge. When required, no mixture will
serve as a substitute. Compounded with aureolin, it becomes softened and
semi-transparent, yielding spring tints of extreme brilliancy and
beauty.

180. SCHEELE'S GREEN,

or _Swedish Green_, resembles the preceding variety in being a compound
of copper and arsenic, and therefore rankly poisonous; but differs from
it in containing no acetic acid, in possessing less opacity, and in
having a darker shade. It is a cupric arsenite, with the common
attributes of emerald green, under which name it is sometimes sold. Of
similar stability, it must not be employed with the true Naples yellow
or antimoniate of lead, by which it is soon destroyed.

Upon the lavish use of this dangerous pigment in colouring toys,
dresses, paper-hangings, artificial leaves, and even cheap
confectionery, it is not our province to enlarge: the constant-recurring
diseases and deaths, which, directly or indirectly, result from the
employment of arsenical pigments, are such every-day facts that they are
merely deplored and forgotten. With arsenic on our heads, our clothes,
our papers, our sweets, our children's playthings, we are so accustomed
to live--and die--in a world of poison, that familiarity with it has
bred contempt. Into the fatal popularity, therefore, of arsenical
colours for decorative purposes, we shall not further enter; but it
behoves us to deprecate their presence, and the presence of all
poisonous pigments, in colour-boxes for the young. It is one of the
pleasures of childhood to suck anything attractive that comes in its
way, openly if allowed, furtively otherwise: and as in early life we
have a preference for brilliancy, so vivid a pigment as Scheele's green
is an object of special attention. Artistically, it matters little
whether a pigment is noxious or not, but we hold that poison should not
be put into the hands of the young; and indeed are of opinion that a box
of colours is about the worst present a child can receive.

181. MALACHITE GREEN,

or _Mountain Green_, is met with in Cumberland, and is also found in the
mountains of Kernhausen, whence it is sometimes called _Hungary Green_.
It is prepared from malachite, a beautiful copper ore employed by
jewellers, and is a hydrated dicarbonate of copper, combined with a
white earth, and often striated with veins of mountain blue, to which it
bears the same relation that green verditer bears to blue verditer. The
colour, which may be extracted from the stone by the process followed
for native ultramarine, varies from emerald-green to grass-green, and
inclines to grey. It has been held in great esteem by some, and
considered strictly stable, on the assumption, probably, that a pigment
obtained from a stone like ultramarine, and by the same method, could
not be otherwise than permanent. That it is so, with respect to light
and air, there is no denying; but the green, when separated from the ore
and purified for artistic use, is merely a carbonate of copper, and
therefore subject to the influence of damp and impure air, in common
with other non-arsenical copper colours. As a pigment, native malachite
green has the same composition, or very nearly the same, as that which
can be artificially produced, and answers to the same tests. Water-rubs
of the two varieties which we exposed to an atmosphere of sulphuretted
hydrogen became equally blackened by the gas. Practically, there is
little or no difference between them: both preserve their colour if kept
from damp and foul air, both are injured by those agents, and both are
liable to darken in time, especially when secluded from light. The
artificial, however, can be obtained of a much finer colour than the
natural, which it may be made to resemble by admixture with mineral
gray. On the whole, they can scarcely be recommended for the palette,
and are certainly inferior in durability to Scheele's and Schweinfurt
greens. In fresco painting they have been pronounced admissible; but,
apart from the question of damp, we should deem the conjunction of lime
with carbonate of copper not favourable to permanence. By the action of
alkalies, even the native green malachite may be converted into blue;
and it becomes a question whether the dingy greenish-blue on some
ancient monuments was not originally malachite green.

182. VERDIGRIS,

or _Viride Æris_, is of two kinds, common or impure, and crystallized or
_Distilled Verdigris_, or, more properly, refined verdigris. The best is
made at Montpellier in France, and is a sub-acetate of copper of a
bright green colour inclining to blue. The least durable of the copper
greens, it soon fades as a water-colour by the action of light, &c., and
becomes first white and ultimately black by damp and foul gas. In oil,
verdigris is permanent with respect to light and air, but moisture and
an impure atmosphere change its colour, and cause it to effloresce or
rise to the surface through the oil. It dries rapidly, and is
exceptionally useful with other greens or very dark colours. In varnish
it stands better; but cannot be considered safe or eligible, either
alone or compounded. Vinegar dissolves it, forming a solution used for
tinting maps, and formerly much employed for colouring pickles, &c.

The painters, who lived at the time when the arts were restored in
Italy, used this pigment; and the bright greens seen in some old
pictures are made by glazings of verdigris. It is often largely
adulterated with chalk and sulphate of copper.

183. MIXED GREEN

Green, being a compound of blue and yellow, may be got by combining
those colours in the several ways of working--by mixing, glazing,
hatching, or otherwise blending them in the proportions of the various
hues required. To obtain a _pure_ green, which consists of blue and
yellow only, a blue should be chosen tinged with yellow rather than with
red, and a yellow tinged with blue. If either a blue or a yellow were
taken, tinged with red, this latter colour would go to produce some grey
in the compound, which would tarnish the green. The fine nature-like
greens, which have lasted so well in some of the pictures of the Italian
schools, appear to have been compounded of ultramarine, or ultramarine
ashes and yellow. Whatever pigments are employed on a painting in the
warm yellow hues of the foreground, and blue colouring of the distance
and sky, are advantageous for forming the greens in landscape, &c.,
because they harmonize better both in colouring and chemically, and
impart homogeneity to the whole: a principle conducive to a fine tone
and durability of effect, and applicable to all mixed tints. In
compounding colours, it is desirable not only that they should agree
chemically, but that they should have, as far as possible, the same
degree of durability. In these respects, aureolin and ultramarine,
gamboge and Prussian blue, Indian yellow and indigo, are all judicious
mixtures, although not all to be recommended.

    PERMANENT YELLOWS.     | PERMANENT BLUES.
                           |
    Aureolin.              | Cerulian Blue.
    Cadmium Yellow, pale.  | Cobalt Blue.
    Cadmium Yellow, deep.  | Genuine Ultramarine.
    Lemon Yellow.          | Brilliant Ultramarine.
    Mars Yellow.           | French Ultramarine.
    Naples Yellow, modern. | New Blue.
    Ochres.                | Permanent Blue.
    Orient Yellow.         |
    Raw Sienna.            |

The foregoing yellows and blues are in no wise inimical to each other,
and yield the best mixed greens, chemically considered, the palette can
afford. In an artistic sense, we confess, the result is not so
satisfactory: the list of blues, it must be admitted, being somewhat
scant. Among the latter there is no pigment with the wonderful depth,
richness, and transparency of Prussian blue, and none consequently which
will furnish with yellow a green of similar quality. That the artist,
therefore, will dispense with Prussian blue, it would be too much to
expect. There is, however, less necessity for it since the introduction
of viridian, a green resembling that which is produced by admixture of
Prussian blue and yellow, and which may be varied in hue by being
compounded with aureolin or ultramarine. Our object in this work is to
give precedence to the chemical rather than the artistic properties of
pigments, to separate the strictly stable from the semi-stable, and the
semi-stable from the fugitive. A colour or a mixture may be chemically
bad but artistically good, and vice versâ; but the chemist looks upon no
pigment or compound with favour unless it be perfectly permanent, and
ignores its mere beauty when void of durability. Hence, all artistic
considerations are set aside in our lists of permanent pigments: if it
be possible to use them alone, so much the better for the permanence of
painting; if not, so much the worse will it be, according to the degree
of fugacity of the colours employed.

184. BRONZE,

and the three succeeding varieties, are greens resembling each other in
being semi-stable, and more or less transparent. Bronze is a species of
Prussian green, of a dull blue-black hue. In its deep washes it appears
a greenish-black with a coppery cast. It is used in ornamental work, and
sometimes as a background tint for flower pieces.

185. CHROME GREENS,

commonly so called, are compounds of chromate of lead and Prussian blue,
a mixture which is also known as _Brunswick Green_. Fine bright greens,
they are suited to the ordinary purposes of mechanic painting, but are
quite unfit for the artist's craft, chrome yellow reacting upon and
ultimately destroying Prussian blue when mixed therewith. For the
latter, cheap cobalts and ultramarines are preferably substituted,
although they do not yield greens of like power and intensity.

Under the names of English Green, Green Cinnabar, &c., 'new' green
pigments have been from time to time introduced, which have turned out
mixtures of Prussian blue and chromate of lead; not made, however, by
compounding the two, but directly by processes similar to the
following:--A mixed solution of the acetates of lead and iron is added
to a mixed solution of the yellow prussiate and chromate of potash, the
necessary acetate of iron being obtained by precipitating a solution of
acetate of lead by sulphate of iron, and filtering the supernatant
liquid. Or; to a solution of Prussian blue in oxalic acid, first
chromate of potash is added, and then acetate of lead.

By the last process, superior and more permanent chrome greens may be
produced, free from lead, by using chloride of barium or nitrate of
bismuth in place of the acetate of lead. Chromate of baryta, or chromate
of bismuth is then formed, neither of which acts on the Prussian blue.

It should be added that where the latter pigment is present, no green
will serve for painting walls containing lime, as its action alters the
tint of the Prussian blue.

186. HOOKER'S GREEN

is a compound of Prussian blue and gamboge, two pigments possessing a
like degree of stability, and perfectly innocuous to each other. It is a
mixture more durable and more transparent than chrome greens made with
chromate of lead. There are two varieties in common use--No. 1, a light
grass green, in which the yellow predominates; and No. 2, a deeper and
more powerful green, with a larger amount of blue.

187. PRUSSIAN GREEN,

like the preceding, is composed of Prussian blue and gamboge; but
contains a very great excess of the former, and is therefore a
bluish-green of the utmost depth and transparency, verging on black in
its deep washes. Yellow ochre may be employed instead of gamboge, but is
not so eligible.

A true Prussian green, which has been recommended as a pigment, can be
produced as a simple original colour, with a base wholly of iron. It is
got by partially decomposing the yellow oxalate of protoxide of iron
with red prussiate of potash. We have made this green and given it a
fair trial, but our verdict is decidedly against it. In colour it is
far from being equal to a good compound of Prussian blue and gamboge,
and it assumes a dirty buff-yellow on exposure to light and air, the
film of blue on the oxalate more or less disappearing.

Another Prussian green, with a base of cobalt, is obtained by
precipitating the nitrate of that metal with yellow prussiate of potash.
According to the mode adopted, and the degree of heat, either a light or
dark green results; but this also is inferior in colour, and presents no
advantage as to permanence.

188. SAP GREEN,

_Verde Vessie_, or _Iris Green_, is a vegetal pigment prepared from the
juice of the berries of the buckthorn, the green leaves of the woad, the
blue flowers of the iris, &c. It is usually preserved in bladders, and
is thence sometimes called _Bladder Green_. When good, it is of a dark
colour and glossy fracture, extremely transparent, and a fine natural
yellowish green. This gummy juice, inspissated and formed into a cake,
is occasionally employed in flower painting. It is, however, a very
imperfect pigment, disposed to attract the moisture of the atmosphere,
and to mildew; while, having little durability in water and less in oil,
it is not eligible in the one and is totally useless in the other.

Similar pigments, obtained from coffee-berries, and named Venetian and
Emerald Greens, are of a colder colour, equally defective and fugitive,
and now obsolete.

189. TERRE VERTE,

or _Green Earth_, is a sober bluish green with a grey cast. It is a
species of ochre, containing silica, oxide of iron, magnesia, potash,
and water. Not bright and of little power, it is a very durable pigment,
being unaffected by strong light or impure air, and combining with other
colours without injury. It has not much body, is semi-transparent, and
dries well in oil. Veins of brownish or reddish ochre are often found
mixed with terre verte, to the detriment of its colour; and there are
varieties of this pigment with copper for their colouring matter, which,
although generally brighter, are inferior in other respects, and not
true terre vertes. Verona Green and Verdetto or Holy Green, are
ferruginous native pigments of a warmer hue. These are met with in the
Mendip Hills, France, Italy, and the island of Cyprus, and have been
used as pigments from the earliest times. Rubens has availed himself
much of terre verte, not in his landscapes merely, but likewise in the
carnation tints in his figures of a dead Christ. It is evident that much
of the glazing is done with this colour: it is, in fact, most useful in
glazing; because, having only a thin substance, it can be rendered pale
by a small portion of white; although in the end it becomes darker by a
concentration of its molecules. Mérimée states that in the greater part
of Alexander Veronese's works--in his Death of Cleopatra, in the Louvre,
for instance--there are some demi-tints which are too green, and which
it is certain were not so originally. Terre verte, therefore, must be
employed with caution; and it would be well to ascertain beforehand
whether a mineral colour will in time become darker than when first laid
on the picture, by putting a drop of oil on the powder in its natural
state. If the tone this gives to it be more intense than that which it
acquires by being ground up, it may fairly be assumed that it will
attain to the same degree of strength whenever, having completely dried,
its molecules shall have re-united as closely as it is possible. Umber
and terra di Sienna are of this class.

In combination with Indian red and Naples yellow, terre verte forms a
series of mild russet greens, of much use in middle distance.

       *       *       *       *       *

190. _Chrome Arseniate_

is an agreeable apple-green colour, prepared from arseniate of potash
and salts of chromic oxide. It is durable, but possesses no advantages
over the chrome oxides, and is of course poisonous.

191. _Cobalt Green_,

Rinman's Green, Vert de Zinc or Zinc Green. True cobalt green is made by
igniting a very large quantity of carbonate of zinc with a very small
quantity of carbonate of cobalt. To give a green tint to an enormous
proportion of the former, an inappreciable amount of the latter will
suffice. Some samples which were analysed, consisted almost entirely of
zinc, there being only two or three per cent. of cobalt present. This
green presents an example of a pigment being chemically good and
artistically bad, or at least indifferent. It is a moderately bright
green, apt to vary in hue according to the mode of manufacture,
permanent both alone and compounded, but so sadly deficient in body and
power, as to have become almost obsolete. With other physical defects,
and a colour inferior to the chrome oxides, cobalt green has never been
a favourite with artists, though justly eulogised by chemists.

192. _Copper Borate_

is obtained by precipitating sulphate of copper with borax, washing the
residue with cold water, and, after drying, igniting it, fusion being
carefully avoided. In this manner, a pretty yellowish green is produced,
which upon longer ignition assumes a dark green shade: the mass is
levigated for use. The compound has the objection of being glassy, and
possessing little body, but is preferable to verdigris as to permanence.

193. _Copper Chrome_

may be prepared by several methods, but the colour is in no case so fine
as Scheele's or Schweinfurt green, nor is it as stable.

194. _Copper Stannate_,

or Tin-Copper Green, equals in colour any of the copper greens free from
arsenic. The cheapest way of making it is to heat 59 parts of tin in a
Hessian crucible with 100 parts nitrate of soda, and dissolve the mass
when cold in a caustic alkali. To the clear solution, diluted with
water, a cold solution of sulphate of copper is added: a reddish-yellow
precipitate falls, which on being washed and dried, becomes a beautiful
green. On the palette it would be superfluous, but for common purposes
might be found of service.

195. _Elsner's Green_

is also a combination of tin and copper. It is made by adding to a
solution of sulphate of copper a decoction of fustic, previously
clarified by a solution of gelatine. To this mixture are added ten or
eleven per cent. of protochloride of tin, and lastly an excess of
caustic potash or soda. The precipitate is then washed and dried,
whereupon it takes a green colour tinged with blue, but without the
brightness or durability of the preceding stannate.

196. _Green Bice_,

or Green Verditer, is the same in substance as blue verditer, which is
converted into green verditer by boiling. This pigment is one of the
least eligible of copper greens.

197. _Green Ochre._

By partially decomposing yellow ochre with prussiate of potash, we have
produced a fine dark blue-green, resembling Prussian green, of great
depth and transparency. There are, however, difficulties in the process;
and the results do not warrant us in pronouncing this green superior or
equal to a mixture of the ochre and Prussian blue.

198. _Green Ultramarine_

is French or artificial ultramarine before the final roasting. It is a
somewhat bright bluish-green, becoming a dull greenish-blue on continued
exposure. Chemically, it is not a bad colour; but artists generally have
decided against it.

199. _Manganese Green_,

or Cassel Green. By several methods, manganate of baryta may be obtained
either as an emerald-green, a bluish-green, or a pale green. The
manganates, however, are decomposed by contact with organic matter; and
hence the green would be liable to suffer from the vehicles employed, as
well as by being compounded with animal or vegetal pigments.

200. _Mineral Green_

is the commercial name of _Green Lakes_, prepared from sulphate of
copper. These vary in hue and shade, have all the properties of the
common non-arsenical copper-greens, and, not being subject to change of
colour by oxygen and light, stand the weather well, and are excellent
for the use of the house-painter, &c. Having a tendency to darken and
blacken by time and foul air, they are not eligible in the nicer works
of fine art.

Another Mineral Green adopted in Germany as a substitute for the
poisonous Schweinfurt green, is composed of chromate of lead, carbonate
of copper, oxide of iron, and chalk. Valueless for the palette, it has
not the beauty of Schweinfurt green, but is recommended as being free
from arsenic. It is not, however, altogether harmless, and should not
be used in confectionery or the like.

201. _Molybdenum Green._

A clear malachite green colour, when dried, is produced from molybdate
of soda and potash-chrome-alum, or from the molybdate and alum with
ammonia. Being more expensive than the chrome oxides and not better, its
introduction, for use by artists, would be attended with no advantage.

There is likewise obtainable a copper molybdate, by adding neutral
molybdate of soda in excess to sulphate of copper. The precipitate is a
very pale green colour, flocculent at first, but crystalline after
washing. Like the chrome molybdate it would be superfluous as a pigment.

202. _Quinine Green_

is rather adapted for a dye than an artist-colour. It is furnished by
acting on quinine with hypochlorite of lime, hydrochloric acid, and
ammonia, successively. Thus prepared, the green resembles a resin,
insoluble in water, but soluble in alcohol, and turned blue by acetic
acid. Its alcoholic solution dyes silk green, and also woollen and
cotton when mordanted with albumen.

203. _Roman Green_,

brought from Rome some years back by a President of the Royal Academy,
appeared to be a mixture of Prussian blue and Dutch or Italian pink. It
was a fugitive compound, which became blue in fading.

204. _Silicate of Baryta._

One part of silica heated to whiteness with three parts of baryta,
yields a pale green solid mass, permanent, but deficient in colour when
ground. It might be employed in enamelling.

205. _Titanium Green_

has been proposed as a substitute for the green arsenical pigments in
common use; but, apart from its expense, the colour is very inferior to
Scheele's green, &c. Titanium green is a ferrocyanide of that metal,
produced by adding yellow prussiate of potash to a solution of titanic
acid in dilute hydrochloric acid, and heating the mixture to ebullition
rapidly. The dark green precipitate is washed with water acidulated with
hydrochloric acid, and dried with great care, since it decomposes at
temperatures above 100°.

206. _Uranium Green_

is an oxide of a deep dull green colour, inclining to olive, and nearly
black when in lumps. A durable but unattractive preparation, equalled in
permanence and far surpassed in beauty by many cheaper compounds.

207. _Vanadium Green_

falls when ferrocyanide of potassium is added to vanadic acid dissolved
in a strong acid. It is a beautiful green precipitate, but at present
simply a curiosity, owing to the rarity of the metal vanadium.

       *       *       *       *       *

Adopting our usual custom of separating the wheat from the chaff, we
point to the opaque and transparent oxides of chromium, Veronese green,
viridian, emerald green, Scheele's green, and terre verte, as more or
less worthy of being dubbed durable.

As semi-stable, malachite green, bronze, Hooker's green, and Prussian
green, must be classed.

Verdigris, chrome greens, and sap green, should be branded as fugitive:
the chrome greens, because they are always commercially composed of
chromate of lead and Prussian blue, two compounds which are semi-stable
in themselves, but become fugacious when compounded.

A reference to the numbered italicised greens will show that there are
many not known to the palette, which are nevertheless very greatly
superior, as regards permanence, to some that disgrace it. Why these
latter are suffered to hold their position is a mystery not easily
explained: it is hard to reconcile the deplored degeneracy of modern
pigments with the popularity of semi-stable and fugitive colours.
Pictures do not stand, is the common cry; therefore, says the public,
there are no good pigments now-a-days. To which we answer, newly built
houses are constantly falling down; therefore there are no good bricks
in these times. Of a truth, one conclusion is as reasonable as the
other: in either case, if rotten materials be used, the result cannot be
lasting; but in neither case does it follow, because such materials are
employed, that there are no better obtainable. A well-built house
implies a conscientious builder, and a well-painted picture implies a
conscientious artist. It is because, we fear, that there are so few
conscientious artists, that there are so few permanent paintings; not,
certainly, because there are no good pigments. In this last belief,
however, the public is encouraged by certain painters, who seek thereby
to excuse their own shortcomings, forgetting that it is a bad workman
who finds fault with his tools. It has been well observed that when
artists speak regrettingly of lost 'systems,' or pigments enjoyed by the
mediævalists and unattainable now, it would be far better were they to
make the best use of existing materials, and study their further
development. There is no need for this cant cry of fugacity, which casts
such a blight on modern art. Durable pigments are not yet obsolete, they
have only to be employed and employed properly to furnish paintings
equal in permanence to those of the old masters. "Titian," says Haydon,
"got his colours from the colour shops on the Rialto, as we get ours
from Brown's; and if Apelles or Titian were living now, they would paint
just as good works with our brushes and colours as with their own."




CHAPTER XIII.

ON THE SECONDARY, PURPLE.


Purple, the third and last of the secondary colours, is composed of
_red_ and _blue_, in the proportions of five of the former to eight of
the latter; proportions which constitute a perfect purple, or one of
such a hue as will neutralize and best contrast a perfect yellow, in the
ratio of thirteen to three, either of surface or intensity. When mixed
with its co-secondary colour, green, purple forms the tertiary _olive_;
and, when compounded with the remaining secondary, orange, it
constitutes in like manner the tertiary _russet_. Of the three secondary
colours it is the coolest, as well as the nearest in relation to _black_
or shade; in which respect, and in never being a warm colour, it
resembles blue. In other respects also, purple partakes of the
properties of blue, which is its archeus, or ruling colour; hence it is
to the eye a retiring colour, that reflects light little, and loses
rapidly in power in a declining light, and according to the distance at
which it is viewed. By reason of its being the mean between black and
blue it becomes the most retiring of all positive colours. Nature
employs this hue beautifully in landscape, as a sub-dominant, in
harmonizing the broad shadows of a bright sunshine ere the light sinks
into deep orange or red. Girtin, who saw Nature as she is, and painted
what he saw, delighted in this effect of sunlight and shadow. As a
ruling colour, whether in flesh or otherwise, purple is commonly too
cold, or verges on ghastliness, a fault which is to be as much avoided
as the opposite extreme of viciousness in colouring, stigmatized as
foxiness.

Yet, next to green, purple is the most generally pleasing of the
consonant colours; and has been celebrated as a regal or imperial
colour, as much perhaps from its rarity in a pure state, as from its
individual beauty. Romulus wore it in his trabea or royal mantle, and
Tullus Hostilius, after having subdued the Tuscans, assumed the pretexta
or long robe, broadly striped with purple. Under the Roman emperors, it
became the peculiar emblem or symbol of majesty, and the wearing of it
by any who were not of the Imperial family, was deemed a "treasonable
usurpation," punishable by death. At the decline of the empire, the
Tyrian purple was an important article of commerce, and got to be common
in the clothing of the people. Pliny says, "Nepos Cornelius, who died in
the reign of Augustus Cæsar, when I was a young man, assured me that
the light violet purple had been formerly in great request, and that a
pound of it usually fetched 100 denaria (about £4 sterling): that soon
after the tarentine or reddish purple came into fashion; and that this
was followed by the Tyrian dibapha, which could not be bought for less
than 1000 denaria (nearly £40 sterling) the pound; which was its price
when P. Lentulus Spinter was Ædile, Cicero being then Consul. But
afterwards, the double-dyed purple became less rare, &c." The Tyrian
purple alluded to was obtained from the purpuræ, a species of shell-fish
adhering to rocks and large stones in the sea adjoining Tyre. On
account, probably, of its extreme costliness, it was frequently the
custom to dye the cloth with a ground of kermes or alkanet, previous to
applying the Tyrian purple. This imparted to the latter a crimson hue,
and explains doubtless the term, double-dyed. The Greeks feigned the
ancient purple to be the discovery of Hercules Tyrius, whose dog, eating
by chance of the fish from which it was produced, returned to him with
his mouth tinged with the dye. Alexander the Great is said to have found
in the royal treasury, at the taking of Susa, purple to the enormous
value of 5000 talents,[A] which had lain there one hundred and
ninety-two years, and still preserved its freshness and beauty.

When inclining to red, purple takes the name of _crimson_, &c.; and when
leaning to blue, the names of _violet_, _lilac_, _mauve_, _&c._ Blue is
a colour which it serves to mellow, or follows well into shade. The
contrast or harmonizing colour of purple is yellow on the side of light
and the primaries; while purple itself is the harmonizing contrast of
the tertiary _citrine_ on the side of shade, and less perfectly so of
the semi-neutral _brown_. As the extreme primaries, blue and yellow,
when either compounded or opposed, afford, though not the most perfect
harmony, yet the most pleasing consonance of the primary colours; so the
extremes, purple and orange, yield the most pleasing of the secondary
consonances. This analogy extends likewise to the extreme tertiary and
semi-neutral colours, while the mean or middle colours furnish the most
agreeable contrasts or harmonies.

In nature pure purple is not a common colour, and on the palette purple
pigments are singularly few. They lie under a peculiar disadvantage as
to apparent durability and beauty of colour, owing to the neutralizing
power of yellowness in the grounds upon which they are laid; as well as
to the general warm colour of light, and the yellow tendency of almost
all vehicles and varnishes, by which the colour of purple is subdued.

208. BURNT CARMINE

is the carmine of cochineal partially charred till it resembles in
colour the purple of gold, for which, in miniature and water-painting,
it is substituted. It is a magnificent reddish purple of extreme
richness and depth, eligible in flower-painting and the shadow of
draperies. As it is generally impossible, however, to alter the nature
of a pigment by merely changing its colour, burnt carmine is scarcely
more permanent than the carmine from which it is produced. If used,
therefore, it should be in body, and not in thin washes or as a glaze.
Durable pigments are admissible in any form; but semi-stable pigments
(gamboge excepted) should only be employed in body.

209. BURNT LAKE

holds the same relation to crimson lake as burnt carmine to ordinary
carmine; and is hence a weaker variety of the preceding, with less
richness, and likewise less permanence.

210. INDIAN PURPLE

is prepared by precipitating an extract of cochineal with sulphate of
copper. It is a very deep-toned but rather cold and subdued purple,
neither so red nor so brilliant as burnt carmine; and is chiefly of
service in draperies. It is apt to lose its purple colour in a great
measure on exposure to light and air, and assume an inky blackness; a
defect which becomes less apparent when the pigment is used in bulk.

211. MARS VIOLET,

_Violet de Mars_, _Purple Ochre_, or _Mineral Purple_, is a dark ochre,
native of the Forest of Dean in Gloucestershire. It is of a murrey or
chocolate colour, and forms cool tints of a purple hue with white. It is
of a darker colour than Indian red, which has also been classed among
purples, but has a similar body and opacity, and generally resembles
that pigment. It may be prepared artificially, and some natural red
ochres burn to this colour. Being difficult and sometimes impossible to
procure, Mars violet is often compounded; in which case it is liable to
vary both in hue and stability. As, however, Indian red is always taken
for its basis, the mixture is never wholly fugitive, nor exhibits any
very glaring contrast on exposure.

212. MIXED PURPLE.

Purple being a secondary colour, composed of _blue_ and _red_, it
follows of course that any blue and red pigments, which are not
chemically at variance, may be employed in producing mixed purples of
any required hue, either by compounding or grinding them together ready
for use, or by combining them in the various modes of operation in
painting. In such compounding, the more perfect and permanent the
original colours are, the more perfect and permanent will be the purple
obtained. To produce a pure purple, neither the red nor the blue must
contain or incline to yellow; while to compound a durable purple, both
the red and the blue must be durable also. Ultramarine and the reds of
madder yield beautiful and excellent purples, equally stable in water or
oil, in glazing or tint, whether under the influence of light or impure
air. Cobalt blue and madder red likewise afford good purples; and some
of the finest and most delicate purples in ancient paintings appear to
have been composed of ultramarine and vermilion, which furnish tints
equally permanent, but less transparent than the above, and less easily
compounded. Facility of use, and other advantages, are obtained at too
great a sacrifice by the employment of perishable mixtures, such as the
lakes of cochineal with indigo.

    PERMANENT REDS. | PERMANENT BLUES.
                    |
    Cadmium Red.    | Cerulian Blue.
    Liquid Rubiate. | Cobalt Blue.
    Madder Carmine. | Genuine Ultramarine.
    Rose Madder.    | Brilliant Ultramarine.
    Mars Red.       | French Ultramarine.
    Ochres.         | New Blue.
    Vermilions.     | Permanent Blue.

It should be noted that all the above reds do not afford pure purples
with blue; those which contain more or less yellow, as cadmium red and
orange vermilion, furnish purples partaking more or less of olive, which
is a compound of purple and green. To those reds may be added the russet
Rubens Madder and the marrone Madder Brown, two pigments which are alike
eligible for mixed purple and mixed orange. No purple, it will be
remarked, equal in gorgeous richness to that produced from crimson lake
and Prussian blue is obtainable from the colours given; just as no mixed
green is of such depth and power if that blue be wanting as a
constituent. But, as our compound tints are given rather as examples of
durability than beauty, all semi-stable or fugitive mixtures are of
necessity ignored.

213. PURPLE MADDER,

_Field's Purple_, or _Purple Rubiate_, is the only durable organic
purple the palette possesses. Marked by a soft subdued richness rather
than by brilliancy, it leans somewhat towards marrone, and affords the
greatest depth of shadow without coldness of tint. Unfortunately, in the
whole range of artistic pigments there is no colour obtainable in such
small quantity as madder purple; hence its scarcity and high price cause
it to be confined to water-colour painting, in which the clearness and
beauty of its delicate tones render it invaluable in every stage of a
drawing. With raw Sienna and indigo or Prussian blue, subdued by black,
it gives beautiful shadow tints, and will be found useful in sky and
other effects compounded with cobalt, rose madder, French blue and
sepia, yellow ochre and cobalt, lamp black and cobalt, light red,
Vandyke brown, burnt Sienna, or aureolin. With great transparency, body,
and depth, it is pure and permanent in its tints, neither gives nor
sustains injury on admixture, dries and glazes well in oil, works well,
and is altogether most perfect and eligible. For fresco it is admirably
adapted, being quite uninjured by lime.

There is a lighter and slightly brighter sort, containing less colouring
matter and more base, which has all the properties of the above with
less intensity of colour. For the sake of cheapness, the purple is
sometimes compounded in oil, generally of brown madder and a blue.
Provided the latter be stable, transparent, and mix kindly, no greater
objection can be taken to this than to the neutral orange of brown
madder and yellow ochre.

214. VIOLET CARMINE

is a brilliant bluish purple of much richness, employed in draperies and
the like. It is prepared by precipitating an alcoholic extract of the
root of the _Anchusa tinctoria_, commonly known as alkanet, a plant
growing in the Levant, and some other warm countries. It was used by the
ancients as a dye, or as a groundwork to those stuffs which were to be
dyed purplish-red: the ladies in ancient times also employed it as a
paint. Its colouring matter or _anchusin_ has the character of a resin,
and is dark-red, softened by heat, insoluble in water, soluble in
alcohol and alkalis, and freely so in ether, fats, and volatile oils, to
all of which it imparts a brilliant red hue. To obtain anchusin, all the
soluble matters are first abstracted from the bruised root by water: it
is then digested in a solution of carbonate of potash, from which it may
be readily precipitated by an acid. Its alcoholic solution yields with
different reagents crimson, flesh-coloured, blue, and violet
precipitates, none of which, however, can be classed as durable. The
variety under notice, violet carmine, resembles the other colours
afforded by alkanet in not being able to withstand the action of light.
On continued exposure, it loses its beauty and brightness, together with
much of its colour, and, like Indian purple, assumes an inky blackness.
Hence it is unsuited to permanently pure effects, and should only be
used in body.

       *       *       *       *       *

215. _Archil Purple._

Archil may be regarded as the English, cudbear as the Scotch, and litmus
as the Dutch name for one and the same substance, extracted from
several species of lichens by various processes. These lichens, which
are principally collected on rocks adjacent to the sea, are cleaned and
ground into a pulp with water, treated from time to time with ammoniacal
liquor, and exposed with frequent agitation to the action of the
atmosphere. Peculiar principles existing in the lichens are, by the
joint instrumentality of the air, water, and ammonia, so changed as to
generate colouring matter, which, when perfect, is expressed. Soluble in
water and alcohol, this colouring principle yields by precipitation with
chloride of calcium a compound known as 'Solid French Purple', a pigment
more stable than the archil colours generally, but all too fugitive for
the palette.

216. _Bismuth Purple._

A purple powder is capable of being produced from bismuth by passing
chlorine gas through the hydrated oxide suspended in a saturated
solution of potash. As soon as the oxide becomes brown-red, the mixture
is boiled and the liquid decanted off at once, the residue being
immediately washed first with alcohol and then with water. On the whole,
the result is not, for an artistic pigment, worth the trouble involved
in the preparation.

217. _Burnt Madder_

is obtained by carefully charring madder carmine until it becomes of the
hue required. Bearing the same relation to madder carmine as burnt
carmine to the carmine of cochineal, burnt madder is a permanent and
perfectly unexceptionable pigment. By reason, probably, of its great
price, it is not mentioned in trade catalogues, and must be held as
commercially unknown.

218. _Cobalt Purples_

are obtainable ranging from the richest crimson purple to the most
delicate violet. We have produced them by wet and dry methods, varying
in brilliancy and beauty, but characterised generally by want of body,
and frequently by a smalt-like grittiness. Chemically, good and stable
colours, they are not received with favour on the palette, and certainly
may be very well replaced by mixtures of cobalt blue and madder red.
When a permanent compound is obtainable equal in colour to an original
pigment, and superior in its physical attributes, no objection can
fairly be taken to its artistic preference. There are other things to be
considered in a pigment besides permanence, or even permanence and
colour combined. The two together do not constitute a perfect pigment,
that is, a material of practical utility and value. In the last
chapter, allusion was made to a green which possesses both the one and
the other, and yet is--at present, at least--quite unfitted for artistic
use. Hence, with a strong partiality for simple original pigments, we
are bound to confess there are cases where mixtures are justifiably
preferred. All we contend for is, that each constituent of such mixtures
should be stable, and neither give nor receive injury by being
compounded.

219. _Gold Purple_,

Purple of Cassius, or Cassius's Purple Precipitate, was discovered in
1683 by Cassius of Leyden. It is a compound of tin and gold, best formed
by mixing aqueous perchloride of iron with aqueous protochloride of tin,
till the colour of the liquid has a shade of green, and then adding this
liquid, drop by drop, to a solution of perchloride of gold, which is
free from nitric acid and very dilute: after twenty-four hours the
purple is deposited. When recently prepared, the colour is brightened by
boiling nitric acid. Not brilliant, but rich and powerful, this purple
varies in hue according to the mode of manufacture from deep crimson to
murrey or dark purple: it also differs in degrees of transparency.
Working well in water, it is an excellent though costly pigment, once
popular in miniatures, but at present rarely, if ever used, as purple
madder is cheaper, and perfectly well supplies its place. Retaining its
colour at a high red heat, it is now confined to enamel and porcelain
painting, and to tinging glass of a fine red. If, whilst in its hydrated
state, it be washed with ammonia, a bright purple liquid results, from
which a violet colour, somewhat less expensive, can be produced, by
combining the gold purple with alumina, and calcining the product in the
same way that is practised with cobalt. This compound may be exposed to
the action of the sun's rays for a year without being sensibly affected.

220. _Prussian Purple._

A prussiate of iron is obtainable of a violet hue, affording good shadow
tints and clear pale washes. It has not, however, been introduced as a
pigment, as ordinary Prussian blue tinged with red furnishes a similar
colour.

221. _Sandal Wood Purple._

Sandal wood contains about 16 per cent. of colouring matter, soluble
with difficultly in water, but readily dissolved by alcohol. From the
latter solution, chloride of tin throws down a purple, and sulphate of
iron a deep violet precipitate; neither of which is remarkable for
permanence.

222. _Tin Violet._

By heating chromate of stannic oxide to bright redness, a dark violet
mass is obtained, which is better adapted to enamel painting than to the
palette. It communicates in glazings a variety of tints, from rose-red
to violet.

       *       *       *       *       *

So scant is the number of good purples in common use, that there are but
two which can be classed as durable, namely, purple madder and the true
Mars violet.

Foremost in the second group stands burnt carmine. As there are
different degrees both of permanence and fugacity, so are there
different degrees of semi-stability. Burnt carmine, burnt lake, Indian
purple, and violet carmine, all belong to this division; but the first
certainly is more permanent than the rest.

Rich and beautiful as it is, purple madder cannot be called brilliant;
while Mars violet is, of course, ochrous. Unlike green and orange,
therefore, purple can point to no original pigment at once vivid and
durable: as regards purple, brilliancy implies a semi-stability that
borders more or less closely on fugacity. Until the advent of a perfect
palette, however, brilliancy and semi-stability will doubtless hold
their own. Their present popularity may be seen by a glance at the lists
of artist-colours--lists compiled, be it remembered, in obedience to
the law of demand and supply. If art were really so much honoured as
some of its disciples pretend, none but durable colours would be
employed. In our opinion, if a picture be worth painting at all, it is
worth painting with permanent pigments; but many evidently think
otherwise. Deploring an error neither flattering to the craft they
practise nor to themselves, we would urge such to bear in mind this
axiom, semi-stable pigments become fugitive when used in thin washes.
Even in body they do not preserve their primitive hue, but in glazing
and the like, their colour altogether flies or is wholly destroyed.

It is this semi-stability, recommended to the thoughtless and
indifferent by the beauty which generally accompanies it, that is the
bane of modern art. Even our greatest painters have yielded to its
fascination. Who has not gazed upon one of Turner's fading pictures with
still more of sadness than enjoyment, that anything so grand, so
beautiful, so true, should slowly but surely be passing away? A feeling
akin to pity is conjured up at the sight of the helpless wreck,
abandoned amid the treacherous materials employed, and sinking deeper
and deeper. Mournful, indeed, is that mighty ruin of mind amid matter;
mournful the thought that in years to come, the monument sought for will
not be found.

FOOTNOTES:

[A] A talent of money, _i.e._, a talent's weight of silver, was equal to
nearly £244.




CHAPTER XIV.

ON THE TERTIARY, CITRINE.


Citrine, or the colour of the citron, is the first of the tertiary class
of colours, or ultimate compounds of the primary triad, yellow, red, and
blue; in which yellow is the archeus or predominating colour, and blue
the extreme subordinate. For citrine being an immediate compound of the
secondaries, _orange_ and _green_, of both which yellow is a
constituent, the latter colour is of double occurrence therein, while
the other two primaries enter singly into its composition. The mean or
middle hue comprehends eight blue, five red, and six yellow, of equal
intensities.

Hence citrine, according to its name, which is that of a class of
colours and used commonly for a dark yellow, partakes in a subdued
degree of all the powers of its archeus yellow. In estimating,
therefore, its properties and effects in painting, it is to be regarded
as participating of all the relations of yellow. By some this colour is
improperly called brown, as almost all broken colours are. The
harmonizing contrast of citrine is a _deep purple_, which may be seen
beautifully opposed to it in nature, when the green of summer declines.
As autumn advances, citrine tends towards its orange hues, including the
colours termed aurora, chamoise, and others before enumerated under the
head of yellow. It is the most advancing of the tertiary colours, or
nearest in relation to light; and is variously of a tender, modest,
cheering character.

To understand and relish the harmonious relations and expressive powers
of the tertiary colours, require a cultivation of perception and a
refinement of taste for which study and practice are needed. To a great
extent the colourist, like the poet, is born not made; but although he
must have an innate sense of the beautiful and the true, hard work
alone, with his head, his eyes, and his hands, will enable him to learn
and turn to account the complex beauties and relations of tertiary
colours. They are at once less definite and less generally evident, but
more delightful--more frequent in nature, though rarer in common art,
than the like relations of the secondaries and primaries. There is very
little pure colour in the world: now and then a gleam dazzles us, like a
burst of sunshine through grey mists; but as a rule, nature prefers
broken colours to absolute hues. Most pure in spring, most full in
summer, most mellow in autumn, most sober in winter, her tints and
shades of colour are always more or less interlaced, from white and the
primaries to the semi-neutral and black.

Of original citrine-coloured pigments there are only a few, unless we
include several imperfect yellows which might not improperly be called
citrines. The following are best entitled to this appellation:--

223. BROWN PINK,

_Brown Stil de Grain_, _Citrine Lake_, or _Quercitron Lake_ is usually
prepared from the berries of Avignon (ramnus infectorius), better known
as French, Persian, or Turkey berries; but a more durable and quicker
drying species is obtained from the quercitron bark. If produced from
the former, it must be branded as fugitive, but if from the latter, it
may be termed semi-stable. In either case it is a lake, precipitated
from the alkaline decoction by means of alum, in such proportions that
the alkali shall not be more than half saturated. The excess of soda or
potash employed imparts a brown hue; but the lake being in general an
orange broken by green, falls into the class of citrine colours,
sometimes inclining to greenness, and sometimes towards the warmth of
orange. It works well both in water and oil, in the latter of which it
is of great depth and transparency, but its tints with white lead are
very fugitive, and in thin glazing it does not stand: the berry variety
dries badly. A fine rich colour, more beautiful than eligible, it is
popular in landscape for foliage in foregrounds. Modified by admixture
with burnt Sienna or gamboge, it yields a compound which, with the
addition of a small quantity of indigo, gives a warm though not very
durable green. In many of the Flemish pictures the foliage has become
blue from the yellowish lake, with which the ultramarine was mixed,
having faded.

It has been remarked that the alteration made by time in semi-stable
pigments is not so observable when they are employed in full body. Their
use generally has been deprecated, but in shadows such vegetable colours
as brown pink are sometimes of advantage, as they are transparent, lose
part of their richness by the action of the air, and do not become
black. Moreover, if mixed with pigments which have a tendency to darken,
they mitigate it very much. This last, indeed, is the most legitimate
purpose to which semi-stable pigments whose colour fades on exposure can
be put.

224. MARS BROWN,

or _Brun de Mars_, is either a natural or artificial ochre containing
iron, or iron and manganese. Of much richness and strict permanence, it
resembles raw umber in being a brown with a citrine cast, but is
generally marked by a flush of orange which is not so observable in the
latter pigment.

225. MIXED CITRINE.

What has been before remarked of the mixed secondary colours is more
particularly applicable to the tertiary, it being more difficult to
select three homogeneous substances of equal powers as pigments than
two, that shall unite and work together cordially. Hence the mixed
tertiaries are still less perfect and pure than the secondaries; and as
their hues are of extensive use in painting, original pigments of these
colours are proportionably estimable to the artist. Nevertheless there
are two evident principles of combination, of which he may avail himself
in producing these colours in the various ways of working; the one being
that of combining two original secondaries; and the other, of uniting
the three primaries in such a manner that the archeus shall predominate.
Thus in the case of citrine, either orange and green may be directly
compounded; or yellow, red, and blue be so mixed that the yellow shall
be in excess.

These colours are, however, obtained in many instances with best and
most permanent effect, not by the intimate combination of pigments upon
the palette, but by intermingling them, in the manner of nature, on the
canvas, so as to produce the appearance at a proper distance of a
uniform colour. Thus composed is the _citrine_ colour of fruit and
foliage, on inspecting which we distinctly trace the stipplings of
orange and green, or of yellow, red, and green. The truth and beauty
resulting from such stipplings in art may be seen in the luscious
fruit-pieces of the late W. Hunt, where the bloom on the plum, the down
of the peach, &c., are given with wondrous fidelity to nature. In the
_russet_ hues of autumn foliage, where purple and orange have broken or
superseded the summer green, this interlacing of colour appears; and
also in the _olive_ foliage of the rose-tree, formed in the individual
leaf by the ramification of purple in green. Besides the durable
yellows, reds, and blues, the following orange and green pigments are
eligible for mixed citrines. They may likewise, however, be safely and
simply compounded by slight additions, to an original brown, of that
primary or secondary tone which is requisite to give it the required
hue.

    PERMANENT ORANGE.  | PERMANENT GREEN.
                       |
    Burnt Roman Ochre. | Oxide of Chromium, opaque.
    Burnt Sienna.      | Oxide of Chromium, transparent.
    Cadmium Orange.    | Veronese Green.
    Mars Orange.       | Viridian.
    Neutral Orange.    | Emerald Green.
                       | Scheele's Green.
                       | Terre Verte.

226. RAW UMBER,

or Umber, is a natural ochre, chiefly composed of oxide of manganese,
oxide of iron, silica, and alumina. It is said to have been first
brought from ancient Ombria, now Spoleto, in Italy. Found in England,
and in most parts of the world, that which comes from Cyprus, under the
name of Turkish or Levant umber, is the best. Of a quiet brown-citrine
colour, semi-opaque, it dries rapidly, and injures no other good pigment
with which it may be mixed. By time it grows darker, a disadvantage
which may be obviated by compounding it with colours which pale on
exposure. For light shadow tones and delicate grays it is extremely
useful, and yields with blue most serviceable neutral greens. To mud
walls, tints for stone, wood, gray rocks, baskets, yellow sails, and
stormy seas, this citrine is suited. Some artists have painted on
grounds primed with umber, but it has penetrated through the lighter
parts of the work. Mérimée states that there are several of Poussin's
pictures so painted; that fine series, "The Seven Sacraments," being
clearly among the number.

       *       *       *       *       *

227. _Cassia Fistula_

is a native vegetal pigment, though it is more commonly employed as a
medicinal drug. It is brought from the East and West Indies in a sort of
cane, in which it is naturally produced. As a pigment it is deep,
transparent, of an imperfect citrine colour, inclining to dark green,
and diffusible in water without grinding, like gamboge and sap green.
Once sparingly used in water as a sort of substitute for bistre, it is
not now to be met with on the palette.

228. _Citrine Brown._

From boiling, hot, or cold solutions of bichromate of potash and
hyposulphite of soda in excess, we have obtained an agreeable
citrine-brown colour, varying in hue and tint according to the mode of
preparation and proportions of materials employed. It is a hydrated
oxide of chromium which, when washed and carefully dried, yields a soft
floury powder. Transparent, and affording clear, delicate pale washes,
the oxide has not been introduced as a pigment; partly owing to certain
physical objections, and partly to a tendency to greenness. This
tendency is peculiar to all the brown chrome oxides of whatever hue,
whether hydrated or anhydrous; and indeed distinguishes more or less
nearly all the compounds of chromium. Green, in fact, is the natural
colour of such compounds, the colour which they are constantly
struggling to attain; and hence it is that the green oxides of chromium,
being clothed in their native hue, are of such strict stability. The
inclination to green which the citrine under notice possesses, may be
seen by washing the precipitate with boiling water. It has been
supposed that hydrated brown oxide of chromium is not a distinct
compound of chromium and oxygen, but a feeble union of the green oxide
with chromic acid. If this be the case, the citrine cast of the brown
oxide is easily explained, as well as the gradual addition to its green
by the deoxidation of the chromic acid.

In mixed tints for autumn foliage and the like, the tendency to green of
this citrine brown would be comparatively unimportant; but whether the
oxide be adapted to the palette or not, we believe the colour might be
utilized. In dyeing, for instance, the solutions of bichromate of potash
and hyposulphite of soda would be worth a trial, the liquids of course
being kept separate, and the brown washed with cold water. Various
patterns could be printed with the bichromate on a ground previously
treated with hyposulphite.

       *       *       *       *       *

Several other browns, and ochrous earths, partake of a citrine hue, such
as Cassel Earth, Bistre, &c. But in the confusion of names, infinity of
tones and tints, and variations of individual pigments, it is impossible
to arrive at an unexceptionable or universally satisfactory arrangement.
We have therefore followed a middle and general course in distributing
pigments under their proper heads.

Of the three citrines in common use, Mars brown and raw umber are
strictly stable; while brown pink, the purest original citrine the
palette possesses, is either semi-stable or fugitive, according to the
colouring substance used in its preparation.




CHAPTER XV.

ON THE TERTIARY, RUSSET.


Russet, the second or middle tertiary colour, is, like citrine,
constituted ultimately of the three primaries, red, yellow, and blue;
but with this difference--instead of yellow as in citrine, the archeus
or predominating colour in russet is red, to which yellow and blue are
subordinates. For _orange_ and _purple_ being the immediate constituents
of russet, and red being a component part of each of those colours, it
follows that red enters doubly into russet, while yellow and blue appear
but once therein. The proportions of its middle hue are eight blue, ten
red, and three yellow, of equal intensities. Thus composed, russet takes
the relations and powers of a subdued red; and many pigments and dyes of
the latter denomination are strictly of the class of russet colours. In
fact, nominal distinction of colours is only relative; the gradation
from hue to hue, as from tint to tint, and shade to shade, being of such
unlimited extent, that it is impossible to pronounce absolutely where
one hue, tint, or shade ends, and another begins.

The harmonizing, neutralizing, or contrasting colour of russet, is a
_deep green_; or when the russet inclines to orange, a _gray_ or
_subdued blue_. These are often beautifully opposed in nature, being
medial accordances or in equal relation to light, shade and other
colours, and among the most agreeable to sense.

Russet, as we have said, partakes of the relations of red, but it is a
hue moderated in every respect, and qualified for greater breadth of
display in the colouring of nature and art; less so, perhaps, than its
fellow-tertiaries in proportion as it is individually more beautiful.
The powers of beauty are ever most effective when least obtrusive; and
its presence in colour should be chiefly evident to the eye that seeks
it--not so much courting as being courted.

Of the tertiary colours, russet is the most important to the artist; and
there are many pigments classed as red, purple, &c., which are of russet
hues. But there are few true russets, and only one original pigment of
that colour is now known on the palette, to wit--

229. RUBENS' MADDER,

_Orange Russet_, _Russet Rubiate_, or _Field's Russet_. This is a very
rich crimson russet with a flush of orange; pure, transparent, and of a
middle hue between orange and purple. Prepared from the madder root, it
is not subject to change by the action of light, time, or mixture of
other pigments. Although not so much employed as the marrone Madder
Brown, it is serviceable both as a local and auxiliary colour in
compounding and producing with yellow the glowing hues of autumnal
foliage, &c.; and with blue, the beautiful and endless variety of grays
in skies, flesh, &c. A good glazing colour, its thin washes afford fine
flesh tints in water: as an oil pigment it dries indifferently, and
requires to be forced by the addition of a little gold size or varnish.
Cappah brown and burnt umber sadden it to the rich tones adapted for
general use in shadows. So saddened, this lake meets admirably the dark
centres of the upper petals of certain fancy geraniums, while alone its
pale washes are equally well suited to the lower leaves.

230. MIXED RUSSET.

What has been remarked in the preceding chapter upon the production of
mixed citrine colours, is likewise applicable to mixed russet. By the
immediate method of producing it materially from its secondaries, good
and durable colours are obtained by compounding the following orange and
purple pigments--

    PERMANENT ORANGE.  | PERMANENT PURPLE.
                       |
    Burnt Roman Ochre. | Mars Violet, true.
    Burnt Sienna.      | Purple Madder.
    Cadmium Orange.    |
    Mars Orange.       |
    Neutral Orange.    |

Many other less eligible duple and triple compounds of russet are
obvious upon principle, and it may be produced by adding red in due
predominance to some browns; but these, like most mixtures, are inferior
to original pigments. To the orange colours there may be added cadmium
red and the orange vermilions, pigments which were classed among the
reds, but which contain sufficient yellow to render them adapted for
either compound russets or compound citrines. And as of original purple
pigments there are two only which are stable, such mixtures as madder
red and French blue will help to swell the list of available permanent
purples. Rubens' madder itself may be changed in hue by being first
mixed with blue and then with orange.

       *       *       *       *       *

231. _Prussiate of Copper_

differs chemically from Prussian blue only in having copper instead of
iron for its basis. It varies in hue from russet to purple brown, is
transparent and deep, but, being very liable to change in colour by the
action of light and by other pigments, has never been much used, and is
now obsolete. The compound has the objection of containing free
prussiate of potash, not removable by continued washing--sometimes as
much as five per cent.

       *       *       *       *       *

There are several other pigments which enter imperfectly into, or verge
upon, the class of russet, which, having obtained the names of other
classes to which they are allied, will be found under other heads; such
are some of the ochres, as Indian red. Burnt carmine is often of the
russet hue, or convertible to it by due additions of yellow or orange;
as are burnt Sienna and various browns, by like additions of lake or
other reds.

The one pigment in this chapter known to the modern palette, Rubens'
madder, is permanent.




CHAPTER XVI.

ON THE TERTIARY, OLIVE.


Olive is the third and last of the tertiary colours, and nearest in
relation to shade. Like its co-tertiaries, citrine and russet, it is
composed of the three primaries, blue, red, and yellow; but is formed
more directly of the secondaries, _purple_ and _green_, in each of which
blue is a constituent: hence blue occurs twice in the latter mode of
forming olive, while red and blue enter therein singly and
subordinately. Blue is, therefore, in every instance the archeus or
predominating colour of olive; its perfect or middle hue comprehending
sixteen of blue to five of red and three of yellow. It partakes in a
proportionate measure of the powers, properties, and relations of its
archeus: accordingly, the antagonist or harmonizing contrast of olive is
a _deep orange_. Like blue, olive is a retiring colour, the most so of
all the colours, being the penultimate of the scale, or nearest of all
in relation to black, and last, theoretically, of the regular
distinctions of colours. Hence its importance in nature and painting is
almost as great as that of black; it divides the office of clothing the
face of creation with green and blue; with both which, as with black and
grey, it enters into innumerable compounds and accordances, changing its
name as either hue prevails, into green, gray, ashen, slate, &c. Thus
the olive hues of foliage are called green, and the purple hues of
clouds are called gray, &c.; but such terms are general only, and
unequal to the infinite particularity of nature.

This infinity, or endless variation of hue, tint, and relation, of which
the tertiaries are susceptible, gives a boundless license to the revelry
of taste, in which the genius of the pencil may display the most
captivating harmonies of colouring, and the most chaste and delicate
expressions; too subtle to be defined, too intricate to be easily
understood, and often too exquisite to be felt by the untutored eye.
Nature always melodizes by imperceptible gradations, while she
harmonizes by distinct contrasts. At different seasons we have blossoms
of all hues, variously subordinated; and when the time of flowers may be
considered past, as if she had no further use for her fine colours, or
were willing to display her ultimate skill and refinement, Nature
lavishes the contents of her palette, not disorderly, but in multiplied
relations, over all vegetal creation, in those rich and beautiful
accordances of broken and finishing colours with which autumn is
decorated ere the year decays and sinks into olive darkness.

As a rule, no colour exists in nature without gradation, which is to
colours what curvature is to lines. The difference in mere beauty
between a gradated and ungradated colour may be seen by laying an even
tint of rose-colour on paper, and putting a rose leaf beside it. The
victorious beauty of the rose, as compared with other flowers, depends
wholly on the delicacy and quantity of its colour gradations, all other
flowers being either less rich in gradation, not having so many folds of
leaf; or less tender, being patched and veined instead of flushed. It is
not enough, however, that colour should be gradated in painting by being
made simply paler or darker at one place than another. Generally, colour
changes as it diminishes, and is not only darker at one spot, but also
purer at one spot than elsewhere; although it does not follow that
either the darkest or the lightest spot should be the purest. Very often
the two gradations more or less cross each other, one passing in one
direction from paleness to darkness, another in another direction from
purity to dulness; but there will almost always be both of them, however
reconciled. Hence, every piece of blue, say, laid on should be quite
pure only at some given spot, from which it must be gradated into blue
less pure--greyish blue, or greenish blue, or purplish blue--over all
the rest of the space it occupies. In Turner's largest oil pictures,
there is not one spot of colour as large as a grain of wheat ungradated;
and it will be found in practice that brilliancy of hue, vigour of
light, and even the aspect of transparency in shade, are essentially
dependent on this character alone; hardness, coldness, and opacity,
resulting far more from equality of colour than from nature of colour.
Given some mud off a city crossing, some ochre out of a gravel pit, a
little whitening, and some coal-dust, and a luminous picture might be
painted, if time were allowed to gradate the mud, and subdue the dust.
But not with the red of the ruby, the blue of the gentian, snow for the
light, and amber for the gold, could such a picture be produced, if the
masses of those colours were kept unbroken in purity, and unvarying in
depth.

Olive being usually a compound colour both with the artist and mechanic,
there are few olive pigments in commerce.

232. MIXED OLIVE

may be compounded in several ways; directly, by mixing green and purple;
or indirectly, by adding to blue a smaller proportion of yellow and red,
or by breaking much blue with little orange. Cool black pigments,
combined with yellow ochre, afford eligible olives; hues which are
called _green_ in landscape, and _invisible green_ in mechanic painting.
It is to be noted that in producing these and other compound colours on
the palette or canvass, those mixtures will most conduce to the harmony
of the performance which are formed of pigments otherwise generally
employed in the picture. Thus, presuming aureolin to be the principal
yellow used, the same yellow should be chosen for compounding orange and
green, or for obtaining indirectly citrine, russet, and olive.

    PERMANENT GREEN.                | PERMANENT PURPLE.
                                    |
    Oxide of Chromium, opaque.      | Mars Violet, true.
    Oxide of Chromium, transparent. | Purple Madder.
    Veronese Green.                 |
    Viridian.                       |
    Emerald Green.                  |
    Scheele's Green.                |
    Terre Verte.                    |

As in the case of russet, there may be added to the two original
purples, mixtures composed of durable reds and blues. There are so many
ways of producing the tertiaries, that no difficulty can be found in
compounding them with stable pigments. Each tertiary may be represented
as follows:--

    CITRINE = Orange          + Green.
       "    = (Yellow + Red)  + (Yellow + Blue.)
       "    = 2 Yellow + Red  + Blue.

    RUSSET  = Orange          + Purple.
       "    = (Yellow + Red)  + (Red + Blue.)
       "    = 2 Red + Yellow  + Blue.

    OLIVE   = Green           + Purple.
       "    = (Yellow + Blue) + (Red + Blue.)
       "    = 2 Blue + Yellow + Red.

From the above equations, and by consulting the lists given of permanent
primary and secondary colours, the artist will at once see how easily
and safely he may vary his mode of compounding the tertiaries.

233. OLIVE GREEN,

sometimes called _Dewint's Green_, is an arbitrary compound, or mixed
green, of a fine deep olive colour and sober richness. Advisedly or not,
it is used in landscape, sketching, &c.; but only in water, olive lake
supplying its place in oil. Like many other compound pigments, it is
either permanent, semi-stable, or fugitive, according to the
constituents of which it is composed. Generally speaking, it is more
beautiful than durable, and is often decidedly fugacious, fading on
exposure. It is impossible for a writer to pronounce an absolute opinion
on the stability of all mixtures sold in a separate form, inasmuch as
the compounds of one firm may differ from those of another. We have
before expressed our dislike to such pigments, and this uncertainty with
regard to their composition serves to strengthen it. Nevertheless, as
there are exceptions to every rule, it must be admitted that the palette
possesses compounds always to be relied upon.

234. OLIVE LAKE

is in commerce exclusively an oil colour. When true, it is a lake
prepared from the green ebony, or laburnum, and is of considerable
permanence, transparency, and depth, both in water and oil; in which
latter vehicle it dries well. This variety, however, may be said to be
obsolete; having given way to a mixture, usually semi-stable, and liable
to blacken.

       *       *       *       *       *

235. _Burnt Verdigris_

is what its name expresses, and is an olive-coloured oxide of copper
deprived of acid. It dries remarkably well in oil, is more durable than
the original verdigris, and is in other respects an improved and more
eligible pigment, although not to be recommended.

236. _Olive Oxide of Chromium._

An olive oxide of this metal is obtainable, transparent, of strict
stability, and altogether superior to any original or compound olive
pigment as yet known. Eligible either in water or oil, it is admirably
adapted for autumn foliage, where a quiet, subdued, nature-like green
is required. It has not, however, been introduced, partly because of its
expense, and partly because a mixture of other pigments with the
ordinary chrome oxides sufficiently answers the purpose. There are more
good colours in the world than are dreamt of in the palette's
philosophy, but either they are not wanted, or are too costly to sell.
In a great measure, both art and science are dependent on commerce.

237. _Olive Rinman's Green._

A compound analogous to cobalt green may be made, of an olive hue, with
more body, and equally stable.

238. _Olive Scheele's Green._

Cupric arsenite, when heated, gives off arsenious acid and water,
leaving a residue of arsenide of copper and copper arseniate. A series
of olive colours is so afforded, which are as durable as their original
pigment, and might with advantage be substituted for the doubtful
compounds at present in use.

239. _Olive Schweinfurt Green_

is likewise furnished by gentle calcination. It may be directly prepared
by mixing boiling aqueous solutions of equal parts of crystallised
verdigris and arsenious acid. An olive-green precipitate is immediately
formed, which is apt, without due precaution, to pass into an emerald
green. A durable copper colour.

240. _Olive Terre Verte._

We have obtained a very beautiful olive from terre verte by simply
changing its hue. In oil, especially, the colour so produced would be
found of service for autumn foliage, or richly painted foregrounds. A
simple original pigment, consisting wholly of the earth, it resembles
ordinary terre verte in being unaffected by strong light or impure air,
and uninjured by admixture; but differs from it in not darkening by
time. Semi-transparent, of sober richness and drying well in oil, it is,
according to its powers, a perfectly unexceptionable colour, of strict
stability.

       *       *       *       *       *

Of the two olive colours in common use, olive lake and olive green, the
first is generally semi-stable, and apt to blacken; while the second is
usually fugitive, and liable to fade: both are compounds. The palette,
therefore, possesses no original olive pigment, good or bad. A glance at
the numbered italicised olives will show that the doubtful mixtures
referred to might with advantage be superseded. It is clear that the
olive pigments which the palette does not know, are better than those
with which it is acquainted.




CHAPTER XVII.

ON THE SEMI-NEUTRAL, BROWN.


As colour, according to the regular scale descending from white, ceases
properly with the last of the tertiaries, olive, in theory the neutral
black would here form a fitting conclusion. Practically, however, every
coloured pigment, of every class or tribe, combines with black as it
exists in pigments--not simply being deepened or lowered in tone
thereby, but likewise defiled in colour, or changed in class. Hence
there arises a new series or scale of coloured compounds, having black
for their basis, which, though they differ not theoretically from the
preceding order inverted, are yet in practice imperfect or impure. These
broken compounds of black, or coloured blacks and greys, we have
distinguished by the term, semi-neutral, and divided them into three
classes: Brown, Marrone, and Gray. What tints are with respect to white,
they are with regard to black, being, so to speak, black tints or
shades.

The first of the series is BROWN, a term which, in its widest
acceptation, has been used to include vulgarly every kind of dark broken
colour, and is, in a more limited sense, the rather indefinite name of a
very extensive class of colours of warm or tawny hues. Accordingly there
are browns of every denomination except blue; to wit, yellow-brown,
red-brown, orange-brown, purple-brown, citrine-brown, russet-brown, &c.
But there is no such thing as a blue-brown, nor, strictly, any other
coloured brown in which blue predominates; such predominance of a cold
colour at once carrying the compound into the class of gray, ashen, or
slate. Brown comprises the hues called dun, hazel, auburn, feuillemort,
mort d'ore, &c.; several of which have been already mentioned as allied
to the tertiary colours.

The term _brown_, then, denotes rightly a warm broken colour, of which
_yellow_ is a chief constituent: hence brown is in some measure to shade
what yellow is to light. Hence, also, proper quantities of either the
three primaries, the three secondaries, or the three tertiaries, produce
variously a brown mixture. Browns contribute to coolness and clearness
by contrast when opposed to pure colours, and Rubens more especially
appears to have employed them upon this principle; although the same may
be said of Titian, Correggio, Paulo Veronese, and all the best
colourists. Being a sort of intermedia between positive colours and
neutrality, browns equally contrast colour and shade. This accounts for
their vast importance in painting, and the necessity of preserving them
distinct from other colours, to which they give foulness in mixture; and
to this is due their use in backgrounds and in relieving of coloured
objects.

The tendency in the compounds of colours to run into brownness and
warmth is one of the common natural properties of colours which
occasions them to deteriorate or defile each other in mixture. Brown by
consequence is synonymous with foul or dirty, as opposed to fair or
clean; and hence brown, which is the nearest of the semi-neutrals in
relation to light, is to be avoided in mixture with light colours. Yet
is it an example of the wisdom of nature's Author that brown is
rendered, like green, a prevailing hue, and in particular an earth
colour, as a contrast which is harmonized by the blueness and coldness
of the sky.

This tendency will likewise explain the use of brown in harmonizing and
toning, as well as the great number of natural and artificial pigments
and colours so called. It was the fertility and abundance of browns that
caused our great landscape-colourist Wilson, when a friend went
exultingly to tell him that he had discovered a new brown, to check him
in his characteristic way, with--"I'm sorry for it: we have gotten too
many of them already." Nevertheless, fine transparent browns are
obviously very valuable.

If red or blue in excess be added to brown, it falls into the other
semi-neutral classes, marrone or gray. The wide acceptation of the term
brown has occasioned much confusion in the naming of colours, since
broken colours in which red, &c. predominate, have been improperly
called brown. That term, therefore, should be confined to the
semi-neutral colours, compounded of, or like in hue to, either the
primary _yellow_, the secondary orange, or the tertiary _citrine_, with
a _black_. The general contrast or harmonizing colour of such compounds
will consequently be more or less purple or blue.

The number of browns is great, as may be seen by the following list.
This list, however, is good, and includes a considerable proportion of
permanent pigments.

241. ASPHALTUM,

_Asphalt_, _Bitumen_, _Mineral Pitch_, _Jew's Pitch_, _Antwerp Brown_,
_Liquid Asphaltum_, &c., is a sort of mineral pitch or tar which, rising
liquid to the surface of the Lacus Asphaltites or Asphaltic Lake (the
Dead Sea) concretes there by the natural action of the atmosphere and
sun, and, floating in masses to the shores, is gathered by the Arabs.
The French give it an additional name from the region of the lake, to
wit, Bitumen of Judea; and with the English, from the same cause, it has
the alias of Jew's pitch. Asphaltum is not so called, however, after
the lake, as is asserted by a writer in the Encyclopædia: it is just the
reverse--Pliny says, "The Asphaltic lake produces nothing but bitumen
(in Greek, asphaltos); and hence its name."

A substance resembling asphalt is found at Neufchâtel in Switzerland,
and in other parts of Europe. A specimen of the native bitumen, brought
from Persia, and of which the author made trial, had a powerful scent of
garlic when rubbed. In the fire it softened without flowing, and burnt
with a lambent flame; did not dissolve by heat in turpentine, but ground
easily as a pigment in pale drying oil, affording a fine deep
transparent brown colour, resembling that of commercial asphaltum; dried
firmly almost as soon as the drying-oil alone, and worked admirably both
in water and oil. Asphaltum may be used as a permanent brown in water,
for which purpose the native is superior to the artificial. The former,
however, is now seldom to be met with, the varieties employed on the
palette being the residua of various resinous and bituminous matters,
distilled for the sake of their essential oils. These residua are all
black and glossy like common pitch, which differs from them only in
having been less acted upon by fire, and thence in being softer. At
present asphaltum is prepared in excessive abundance as a product of the
distillation of coal at the gas manufactories, and is chiefly confined
to oil-painting, being first dissolved in turpentine, which fits it for
glazing and shading. Its fine brown colour and perfect transparency are
lures to its free use with many artists, notwithstanding the certain
destruction that awaits the work on which it is much employed, owing to
its tendency to contract and crack by changes of temperature and the
atmosphere; but for which, and a slight liability to blacken, it would
be a most beautiful, durable, and eligible pigment. The solution of
asphaltum in turpentine, united with drying oil by heat, or the bitumen
torrefied and ground in linseed or drying-oil, acquires a firmer
texture, but becomes less transparent and dries with difficulty. If
common asphaltum, as usually prepared with turpentine, be used with some
addition of Vandyke brown, umber, or Cappah brown ground in drying oil,
it will gain body and solidity which will render it much less disposed
to crack. Nevertheless, asphaltum is to be regarded in practice rather
as a dark varnish than as a solid pigment, and all the faults of a bad
varnish are to be guarded against in employing it.

It is common to call the solution in turpentine _Asphaltum_, and the
mixture with drying-oil _Bitumen_: the latter is likewise known as
_Antwerp Brown_. A preparation for the use of water-colour artists is
employed under the name of _Liquid Asphaltum_.

242. BISTRE

is extracted by watery solution from the soot of wood fires, whence it
derives a strong pyroligneous scent. It is a very powerful
citrine-brown, washes well, and has a clearness suited to architectural
subjects. Its use is confined to water-colour painting, in which it was
much employed by the old masters for tinting drawings and shading
sketches, before the general application of Indian ink to such purposes.
Of a wax-like texture, it is perfectly durable, but unfitted for oil,
drying therein with the greatest difficulty.

A substance of this kind collects at the back of fire-places in cottages
where peat is the constant fuel burnt; which, purified by solution and
evaporation, yields a fine bistre, similar to the Scotch. All kinds of
bistre attract moisture from the atmosphere.

243. BONE BROWN

and _Ivory Brown_ are obtained by roasting bone and ivory until by
partial charring they become of a brown colour throughout. Though much
esteemed by some artists, they are not quite eligible pigments, being
bad driers in oil, the only vehicle in which they are now used.
Moreover, their lighter shades are not permanent either in water or oil
when exposed to the action of strong light, or mixed in tint with white
lead. The palest of these colours are the most opaque: the deepest are
more durable, and most so when approaching black. Neither bone nor ivory
brown is often employed, but the former may be occasionally applied in
forming clear, silvery, warm grays, in combination with zinc white.

244. BURNT UMBER

is what its name denotes, and has a deeper shade with a more russet hue
than the raw umber. A quiet brown, it affords clear and warm shadows,
but is apt to look rather turbid if used in great depth. It washes and
works capitally in water, and dries quickly in oil, in which it is
employed as a siccative. Perfectly stable in either vehicle, it may
sometimes be substituted for Vandyke brown, is eligible in fresco, and
invaluable in buildings. Where the lakes of madder require saddening,
the addition of burnt umber increases their powers, and improves their
drying in oil. It contains manganese and iron, and may be produced
artificially. The old Italians called it _falsalo_.

245. CALEDONIAN BROWN

is a permanent native pigment, the use of which is confined to oil. A
magnificent orange-russet brown of considerable transparency, it is
marked by great depth and richness, and will be found serviceable where
a powerful brown of the burnt Sienna class is required.

246. CAPPAH BROWN,

or _Cappagh Brown_, is likewise a colour peculiar to oil. It is a
species of bog-earth or peat, mixed with manganese in various
proportions, and found on the estate of Lord Audley at Cappagh, near
Cork. The specimens in which the peat earth most abounds are of light
weight, friable texture, and dark colour; while those which contain more
of the metal are heavy and paler.

As pigments, the peaty Cappah brown is the most transparent and rich in
colour. A prompt drier in oil, its surface rivels during drying where it
lies thick. The other and metallic sort is a more opaque, a lighter and
warmer brown pigment, which dries rapidly and smoothly in a body or
thick layer. The first may be regarded as a superior Vandyke brown, the
second as a superior umber. The two extreme kinds should be
distinguished as light and deep Cappah browns; the former excellent for
dead colouring and grounds, the latter for glazing and graining. These
pigments work well in oil and varnish; they do not, however, keep their
place while drying in oil by fixing the oil, like the driers of lead,
but run. Under the names of _Euchrome_ and _Mineral Brown_, they have
been introduced into commerce for civil and marine painting.

247. CASSEL EARTH,

_Terre de Cassel_, or, corruptly, _Castle Earth_, is specially an oil
pigment, similar to burnt umber but of a more russet hue. It is an earth
containing bitumen, a substance which, with pit-coal, lignite or brown
coal, jet, petroleum or rock oil, naphtha, &c., is looked upon as a
product of the decomposition of organic matter, beneath the surface of
the earth, in situations where the conditions of contact with water, and
almost total exclusion of atmospheric air, are fulfilled. Deposited at
the bottom of seas, lakes, or rivers, and subsequently covered up by
accumulations of clay and sand, the organic tissue undergoes a kind of
fermentation by which the bodies in question are slowly produced. The
true bitumens appear to have arisen from coal or lignite by the action
of subterranean heat; and very closely resemble some of the products
yielded by the destructive distillation of those bodies.

Rich as is the tone of colour of Cassel earth, it is apt to lose this in
some measure on exposure to light. Mérimée remembers to have seen a
head, the brown hair of which had been painted partly with the earth
alone, and partly with a mixture of the earth and white; yet the hair
where the white was employed was darker than that painted solely with
the brown, the white having fixed the colour. To compensate for its
thus fading, it should be mixed with pigments that are permanent, such
as umber and lamp black. Like all bituminous earths, it needs the
strongest drying oil. By calcination, a greater degree of intensity may
be imparted to the colour, and perhaps a little more solidity. In
landscapes it is of much service for the most vigorous portions of
foregrounds and the trunks of trees, as well as for painting cavernous
rocks or deep recesses in architecture. Compounded with burnt lake and a
little Prussian blue, it gives a black the most profound.

248. CHALON'S BROWN

is a water-colour pigment, transparent and inclining to red; deep, full,
and very rich. On exposure to light it becomes less russet, but is
otherwise strictly stable.

249. COLOGNE EARTH,

incorrectly called _Cullen's Earth_, is a native bituminous earth,
containing less bitumen than Cassel earth, and therefore drying more
quickly. Darker than that variety, it is less transparent, and covers
better. In its general qualities it resembles Vandyke brown, except that
in combination with white, it affords a range of cooler brown tints.
Useful for the shadows of buildings, it does not wash so well as sepia,
and is preferred occasionally on that account. By some it has been
called durable, by others branded as fugacious. According to Bouvier,
brown hair represented by this colour has been known to disappear in six
months, all the brown vanishing, and nothing remaining but a few black
lines of the sketch. As it is similar in composition to Cassel earth,
the safest course would be to mix it with umber, and not to employ it
alone. Calcined, it acquires a reddish hue.

250. INDELIBLE BROWN INK.

Although this cannot be classed as a pigment, yet, being very useful in
water-colours, it may be proper to describe its qualities. The ink is a
rich brown fluid, and, as its name imports, is indelibly fixed on the
paper as soon as it is dry; thus allowing the artist to work or wash
over it repeatedly, without its being disturbed. If diluted with water
to its faintest tint, it still continues to retain its indelible
properties undiminished. It is generally used with a reed pen, and
employed chiefly in architectural details and outlines.

Various brown inks, principally solutions of bistre and sepia, were
adopted in sketching by Claude, Rembrandt, and many of the old masters.
In modern times, a beautiful transparent brown for water-colour artists,
known as _Liquid Prout's Brown_, has been extensively employed. This
contains less fixative than the indelible ink, and is the vehicle with
which nearly all Samuel Prout's drawings were executed.

251. LEITCH'S BROWN

is a permanent pigment peculiar to water painting. A most beautiful
olive brown, soft and rich, it is admirably adapted for autumnal foliage
tints and the like, either alone or compounded with burnt Sienna or
cadmium orange. Transparent and clear in its washes, this is a most
serviceable colour in landscape generally.

252. MIXED BROWN

can be produced in endless variety, either by adding a warm colour to
black, such as yellow, orange, or citrine, or else by combining the
three primaries, secondaries, or tertiaries in suitable proportions. By
consulting the lists given of permanent pigments belonging to those
classes, and by referring to the chapter on Black, it will be seen that
no difficulty exists in obtaining durable mixed browns when required.
For example, there may be formed from the primaries, a compound of
aureolin, rose madder, and ultramarine; or from the secondaries, a
mixture of cadmium orange, viridian, and madder purple. Of course, as
with other mixed tints, the brown hue can be furnished not only by
direct compounding of the colours on the palette, but by laying one
colour over the other on the paper or canvass, or by stippling.

253. MUMMY,

_Mummy Brown_, or _Egyptian Brown_, is a bituminous product mixed with
animal remains, brought from the catacombs of Egypt, where liquid
bitumen was employed three thousand years ago in embalming. By a slow
chemical change, it has combined during so many ages with substances
which give it, as a rule, a more solid and lasting texture than simple
asphaltum. Generally resembling the latter in its other properties and
uses as a pigment, mummy is often substituted for it, being less liable
to crack or move on the canvass. It must be remembered, however, that
mummy varies exceedingly both in its composition and qualities; and as
from its very nature and origin nothing certain can be said of it, but
little reliance should be placed on this brown. Mummy belongs to the
class of pigments which are either good or bad, according as they turn
out. On the whole, we agree with the American artist, who has been more
than once quoted in these pages, that nothing is to be gained by
smearing one's canvass with a part, perhaps, of the wife of Potiphar.
With a preference for materials less frail and of a more sober
character, we likewise hold with Bouvier, that it is not particularly
prudent to employ without necessity these crumbled remains of dead
bodies, which must contain ammonia and particles of fat in a concrete
state and so be more or less apt to injure the colours with which they
may be united. The use of mummy is now confined to oil, in which, says
Mr. Carmichael, a mixture of mummy and bitumen will dry and never crack.
If this be the case, the compound would be preferable to either
separate.

254. PRUSSIAN BROWN

is an iron oxide, containing more or less alumina, and prepared by
calcining an aluminous Prussian blue, or treating an aluminous
ferrocyanide of peroxide of iron with an alkali. Possessing the nature
and properties of burnt Sienna, it is transparent, permanent, and dries
well in oil. Of an orange hue, it is neither so rich nor so powerful as
that pigment, and is better employed as a glaze than in body.

255. SEPIA,

_Liquid Sepia_, _Seppia_, or _Animal Æthiops_, is named after the sepia
or cuttle-fish, also called the ink-fish, from its affording a dark
liquid, which was used as an ink and pigment by the ancients. All the
species of cuttle-fish are provided with a dark-coloured fluid,
sometimes quite black, which they emit to obscure the water, when it is
wanted to favour their escape from danger, or, by concealing their
approach, to enable them with greater facility to seize their prey. The
liquid consists of a mass of extremely minute carbonaceous particles,
intermixed with an animal gelatine or glue, and is capable of being so
widely spread, than an ounce of it will suffice to darken several
thousand ounces of water. From this liquid, brought chiefly from the
Adriatic, but likewise obtainable from our own coasts, is derived the
pigment sepia, as well as, partially, the Indian ink of the Chinese.

Sepia is a powerful dusky brown, of a fine texture, transparent, works
admirably in water, combines cordially with other pigments, and is very
permanent. It is much used as a water-colour, and for making drawings in
the manner of bistre and Indian ink; but is not employed in oil, as it
dries therein very reluctantly. Extremely clear in its pale tints, and
perhaps the best washing colour known, sepia must be used with caution,
or otherwise heaviness will be engendered in the shades, so strong is
its colouring property. Mixed with indigo, or, preferably, Prussian blue
and black, it is eligible for distant trees, for a general shadow tint
in light backgrounds, and for the shade of white linen or white
draperies. With madder red it forms a fine hue, somewhat resembling
brown madder, and with crimson lake and indigo gives an artistically
excellent black. Sometimes alone and sometimes in combination with lamp
black, or madder red and Prussian blue saddened by the black, it will be
found useful in dark foreground boats, rocks, near buoys, sea-weed, &c.
Compounded with aureolin, sepia yields a series of beautiful and durable
neutral greens for landscape; and mixed with Prussian blue, affords low
olive greens, which may be deepened into very cool dark greens by the
addition of black. For hills and mountains in mid-distance, sepia
combined with cobalt and brown madder is of service; or, for the dark
markings and divisions of stones in brooks and running streams, the same
compound without the cobalt. Mixed with purple madder, it furnishes a
fine tint for the stems and branches of trees; and with French blue and
madder red gives a really good black. Compounds of sepia and yellow
ochre, gamboge, raw Sienna, or cobalt and aureolin, are severally
useful. A rich and strong brown is formed by the admixture of madder
red, burnt Sienna, and sepia; a tint which may be modified by omitting
the sepia or the Sienna, or reducing the proportions of either. For
Dutch craft, this tint and its variations are of great value. A wash of
sepia over green very agreeably subdues the force of the colour.

256. WARM SEPIA

is the natural sepia warmed by mixture with other browns of a red hue,
and is intended for drawings where it would be difficult to keep the
whole work of the same tint, unless the compound were made in the cake
of colour.

257. ROMAN SEPIA

is a preparation similar to the preceding, but with a yellow instead of
a red cast.

258. VANDYKE BROWN.

This pigment, hardly less celebrated than the great painter whose name
it bears, is a species of peat or bog-earth of a fine, deep,
semi-transparent brown colour. The pigment so much esteemed and used by
Vandyke is said to have been brought from Cassel; an assertion which
seems to be justified by a comparison of Cassel earth with the browns of
his pictures. Gilpin in his Essays on Picturesque Beauty, remarks that
"In the tribe of browns--in oil-painting, one of the finest earths is
known, at the colour shops, by the name of Castle-earth, or Vandyke's
brown." The Vandyke brown of the present day is a bituminous ochre,
purified by grinding and washing over. Apt to vary in hue, it is durable
both in water and oil, but, like all bituminous earths, dries tardily as
a rule in the latter vehicle. Clear in its pale tints, deep and glowing
in shadows, in water it has sometimes the bad property of working up:
for this reason, where it is necessary to lay on a great body of it,
the moist tube colour should be preferred to the cake. With madder red,
the brown gives a fine tint, most useful as a warm shadow colour; and
with Prussian blue, clear, very sober neutral greens for middle
distances. In banks and roads, Vandyke brown is the general colour for
dragging over the surface, to give roughness of texture: compounded with
yellow ochre, it affords a good ground tint, and with purple madder a
rich shadow colour. In sunrise and sunset clouds, a mixture of the brown
with cobalt yields a cold neutral green, adapted for those clouds at the
greatest distance from the sun. For foliage tints, aureolin, French
blue, and Vandyke brown, will be found of service; or as a glaze over
such tints, the yellow and the brown. With raw Sienna, brown madder,
Payne's gray, gamboge, and Roman ochre, this brown is useful. In a
water-colour winter scene, when the trees are denuded of foliage, the
net work of the small branches at the tops of them may be prettily given
with cobalt and Vandyke brown, used rather dry, and applied with a brush
having its hairs spread out either by the fingers or by drawing them
through a fine-tooth comb before working. Grass is likewise represented
readily by this means, and so are small trees on the summit of a cliff
or in like positions.

The Campania Brown of the old Italian painters was a similar earth.

259. VERONA BROWN,

a pigment peculiar to oil painting, is a native ferruginous earth. A
citrine brown of great service in tender drab greens, it forms with
terre verte and the madder lakes rich autumnal tints of much beauty and
permanence.

260. YELLOW MADDER,

_Cory's Yellow Madder_, or _Cory's Madder_, is classed among the browns
for the same reason that Italian Pink was ranked among the yellows. It
was stated in the eighth chapter that no true madder yellow, brilliant
and pure, exists as a pigment at the present day, and certainly this
preparation can lay no claim to the title. Except in name, it is an
orange-brown of the burnt Sienna hue, and might therefore with more
reason have been called Orange Madder. It is a good and permanent
colour, rich and transparent, at present used only in oil, we believe,
and chiefly as a glaze.

       *       *       *       *       *

261. _Cadmium Brown_.

By igniting the white carbonate of cadmium, among other methods, a
cinnamon-brown oxide is obtainable, of a very clear and beautiful colour
if the process be well conducted. It is, however, not eligible as a
pigment, owing to the rapidity with which the oxide is acted upon by the
air. In water, especially, we have found this brown so eagerly absorb
carbonic acid from the atmosphere as to become in a few months once more
a carbonate, and as purely white as before. The same result is
observable when the powder is exposed: some shown at the International
Exhibition of 1862, on a glass stand, had to be removed, its label
marked 'Cadmium Brown' being at last found attached to a sample of
cadmium white. In oil, the conversion takes place less readily, that
vehicle having the property of protecting, to some extent, pigments from
oxidation. It is curious that even in a book a water-rub of the brown
slowly but surely changes to white.

262. _Catechu Browns._

Catechu is an extract of the Khair tree or _acacia catechu_ of Bombay,
Bengal, and other parts of India. With the exception of such earthy
matters as are communicated to it during the preparation, or are added
purposely as adulterants, catechu is entirely soluble both in water and
alcohol. An aqueous solution has a reddish-brown colour, and gives the
following results:--protosalts of iron thrown down olive-brown and
persalts greenish-brown precipitates; salts of tin and lead yield
brownish-yellow and brick-coloured deposits respectively; while acetate
of copper or bichromate of potash furnishes brown residues. To our
knowledge, none of these have been introduced as pigments, but a brown
prepared by Dr. Lyon Playfair some years back from the catechu bark has
been described as exceedingly rich, transparent, and beautiful; and
recommended for painting _if not too thinly applied_.

263. _Chrome Browns_

are produced by various methods of several hues, tints, and shades, both
by wet and dry processes. We have obtained them by many methods, of
different degrees of permanence. Some very intense in colour have stood
well, while others paler and more delicate have gradually greened, but
none possessed the strict stability of the green oxides. Presuming a
paucity of browns, these preparations of chromium would be worth further
attention; but, with the objection of being--for browns--somewhat
expensive, they have the far more fatal objection of not being wanted.

264. _Copper Brown_,

varying in hue, is obtainable, in the form of prussiate, &c., but cannot
be recommended, however made.

265. _French Prussian-Brown._

According to Bouvier, a colour similar to that of bistre, and rivalling
asphaltum in transparency, is produced by partially charring a
moderately dark Prussian blue; neither one too intense, which gives a
heavy and opaque brownish-red, nor one too aluminous and bright, which
yields a feeble and yellowish tint. Yielding to a rapture we cannot
wholly share, he describes its qualities in the warmest terms. In his
opinion, it has the combined advantages of asphaltum, mummy, and raw
Sienna, without their drawbacks. "I cannot," he says, "commend too
highly the use of this charming bistre-tint: it is as beautiful and good
in water as in oil, perfectly transparent, of a most harmonious tone,
and dries better than any other colour suitable for glazing. Closely
resembling asphaltum in tint as well as in transparency, this brown is
preferable to it in every point of view." As the colour is very quickly
and easily obtained, the artist can judge for himself of its proper
value. M. Bouvier's process is, to place upon a clear fire a large iron
spoon, into which, when red hot, some pieces of the Prussian blue are
put about the size of a small nut: these soon begin to crackle, and
throw off scales in proportion as they grow hot. The spoon is then
removed, and allowed to cool: if suffered to remain too long on the
fire, the right colour will not be produced. When the product is crushed
small, some of it will be found blackish, and the rest of a yellowish
brown: this is quite as it should be. Chemically, the result is a
mixture of oxide of iron and partly undecomposed or carbonised
prussiate.

266. _Gambogiate of Iron._

Dr. Scoffern read a paper at the Meeting of the British Association of
Science, in 1851, describing this combination as a rich brown, like
asphaltum, but richer, as well as more durable in oil. It has not been,
however, employed as a pigment, or at least is not at present.

267. _Hypocastanum_,

or Chestnut Brown, is a brown lake prepared from the horse-chestnut.
This now obsolete pigment is transparent and rich in colour, warmer than
brown pink, and very durable both in water and oil; in the latter of
which it dries moderately well.

268. _Iron Browns_,

native or artificial, are well represented on the palette, but nothing
would be easier than to increase their number. Of all metals, iron is
the richest source of colour, capable of affording all colours with the
exception of white. None of them, however, are so numerous as the
browns, a description of which would fill this chapter. Suffice it to
state they are obtainable of every hue, tint, and shade, and are
generally permanent. They are made on a large scale and sold under
various names for house-painting, &c.

269. _Manganese Brown_

is an oxide of manganese, which is quite durable both in water and oil,
and dries admirably in the latter. A fine, deep, semi-opaque brown of
good body, it is deficient in transparency, but might be useful for
glazing or lowering the tone of white without tinging it, and as a local
colour in draperies, &c.

270. _Nickel Brown._

A very pleasing yellowish brown is obtainable from nickel, bright and
clear in its pale washes, and of some richness in oil. Unless thoroughly
washed, it has a tendency to greenness in time.

271. _Ochre Browns._

The slight affinity of sulphur for yellow ochre, with its merely
temporary effect thereon, was observed in the eighth chapter, where
allusion was made to the action of sulphuretted hydrogen and sulphide of
ammonium on the earth. Sulphur alone, and in the dry state, ignited with
yellow or other native ochres converts them into browns, varying in hue,
and of greater or less durability. Those browns, however, which we have
made by this process, although standing well in a book, have not
withstood exposure to light and air. They have all become pale, whitish,
or of a drab cast, evidently through the oxidation of the sulphur, or
rather the sulphide of iron formed during the calcination. Practically,
therefore, ochres have an antipathy to sulphur, moist or dry, by itself
or in combination; and are, so to speak, the disinfectants of the
palette. Ever waging war against sulphurous vapours, the native earths
serve to protect a picture from the damaging influence of impure air,
whether they be used alone, or employed in admixture with such pigments
as are injured thereby.

272. _Purple Brown_

is a refuse manufacture from Indian red washings. A dull, heavy, coarse
colour, it belongs to the class of common pigments which are
unexceptionable for decorative painting, but scarcely suited to the
higher branches of art. As this work professes simply to treat of
artistic pigments, that have been, are, or might be, more than a passing
reference to those colours exclusively adopted by house-painters, &c.,
would be out of place.

273. _Rubens' Brown_,

still in use in the Netherlands under this appellation, is an earth of
a lighter colour and more ochrous texture than the Vandyke brown of
English commerce: it is also of a warmer or more tawny hue than the
latter pigment. Beautiful and durable, it works well both in water and
oil, and much resembles the brown employed by Teniers.

274. _Uranium Brown._

Yellow, red, orange, green, have been previously noticed as being
derived from uranium, and to this list of colours may now be added
brown. A warm rich hue of the utmost intensity may be produced, which
possesses considerable permanence, although not equal to that of uranium
yellow.

275. _Zinc Brown._

A yellow-brown, so yellow that it might fairly have been classed with
the ochrous colours of that denomination, is made by combining zinc with
another metal by the aid of heat. Experience tells us that it is,
chemically, a thoroughly good and stable pigment. Safely to be used in
admixture, it is a clear, bright colour, affording good greens by
compounding with blue. Of no great power, and semi-opaque, this
yellow-brown or brown-yellow is superior to some of the pigments at
present used, but is probably too much like them in hue and other
properties to be of any special value.

       *       *       *       *       *

Besides the preceding, there are those browns of a citrine or russet
cast which are elsewhere described, such as raw umber, madder brown, &c.
Moreover, there are numberless other varieties, obtainable from most of
the metals, from many organic substances, and from a combination of the
two. Of all colours, a 'new' brown is the most easily discovered:
success may not be met with in seeking a yellow, red, or blue, or an
orange, green, or purple; but it is strange if in the course of one's
experiments a brown does not turn up. No difficulty, therefore, would
have been found in greatly extending the present list; but it was felt
that no advantage could have accrued by further multiplying the notices
of a colour, with which we are already furnished so abundantly by nature
and art, and which is capable of being produced in such profusion by
admixture.

With the exception of ivory and bone browns, and perhaps Cassel and
Cologne earths, all the browns commonly employed may be considered more
or less durable.




CHAPTER XVIII.

ON THE SEMI-NEUTRAL, MARRONE.


We have adopted the term MARRONE, or _maroon_ as it is sometimes called,
for our second and middle semi-neutral, as applicable to a class of
impure colours composed of black and red, black and purple, or black and
russet, or of black and any other denomination in which red
predominates. It is a mean between the warm, broken, semi-neutral
_browns_, and the cold, semi-neutral _grays_. Marrone is practically to
shade, what red is to light; and its relations to other colours are
those of red, &c., when we invert the scale from black to white. It is
therefore a following, or shading, colour of red and its derivatives;
and hence its accordances, contrasts, and expressions agree with those
of red degraded; consequently red added to dark brown converts it into
marrone if in sufficient quantity to prevail. In smaller proportions,
red gives to lighter browns the names of bay, chestnut, sorrel, &c.

Owing to confused nomenclature, most of the colours and pigments of
this class have been assigned to other denominations--puce, murrey,
morelle, chocolate, columbine, pavonazzo, &c., being variously ranked
among reds, browns, and purples. This vagueness also accounts for
pigments having been ranged under heads not suited to the names they
bear, and explains why Brown Ochre has been classed among the yellows,
Italian Pink among the same, Brown Pink among the citrines, &c.

As adapted to the walls of a picture gallery, marrone, more or less deep
and inclined to crimson, is one of the best colours known. For the
reason that each colour has its antagonist, and consequently may affect
a picture well or ill, according to its tone or general hue, there can
be no universally good colour for such a purpose. What suits one picture
or style of painting may not suit another: with a blood-red sunset, for
instance, or portrait with crimson drapery, marrone would be out of
place. But as it is impossible to provide each picture with a separate
background, all that can be done in large collections is to study the
general effect, sacrificing the interests of the few to the good of the
many. If cool-coloured landscapes predominate, with blue skies and green
foliage, it will be found that the orange-yellow of the frames agreeably
contrasts the former, and the crimson-marrone of walls as agreeably sets
off the latter. If portraits and historic paintings prevail, which are
in general of a warm advancing nature, then a modest green may prove
eligible. And if engravings form the staple, the grey hue of the print
is best opposed by a bright fawn colour. Where several rooms are devoted
to pictures, a suitable wall colour is most easily secured by
classifying the paintings as far as possible according to their general
hue, and placing them in different chambers: in each there will be a
prevailing character in the colouring of its pictures, and each can be
painted or papered accordingly. However, whether this plan is adopted or
not--and it may be objected to as involving a certain monotony--care
should be taken to have a wall colour of some sort or other, that is, to
let it be seen. Pictures crammed together kill each other: without a
pin's point between them, a speck of wall space visible, much of the
illusion is destroyed. "It is only," says Chevreul, "the intelligent
connoisseur and amateur who, on seeing a picture exhibited in a gallery,
experience all the effect which the artist has wished to produce;
because they alone know the best point of view, and because, while their
attention is fixed on the work they are observing, they alone end by no
longer seeing the surrounding pictures, or even the frame of that one
they contemplate." Amid a moving crowd of people, inseparable from
nearly all public exhibitions, it becomes difficult for the visitor,
intelligent or otherwise, thus to concentrate his attention on one work.
As far, therefore, as space will allow, paintings should be kept
separate: larger rooms, or fewer pictures, are what is wanted.[B]

From this digression, pardonable, let us hope, because in the interests
of art, we will pass on to a consideration of marrone pigments.

276. BROWN MADDER

is an exceedingly rich marrone or russet-marrone brown, bearing the same
relation to the colour marrone that raw umber bears to the colour
citrine. One of the most valuable products of the madder root, it has
supplied a great desideratum, and in water especially is indispensable,
both as a local and auxiliary colour. Of intense depth and transparency,
if made with skill, it affords the richest description of shadows,
either alone or compounded with blue, and the most delicate pale tints.
Being quite permanent, a good drier, and working most kindly, it is a
pigment which cannot be too strongly recommended to the landscape
painter's notice. Containing a large proportion of red, it is eligible,
with yellow or blue, for mixed orange or mixed purple of a subdued tone.
It may be used tolower red curtains or draperies, and for the darkest
touches in flesh. Mixed with cobalt, it forms a fine shadow colour for
distant objects; and with indigo or Prussian blue and black, is
serviceable for the shades of those nearer the foreground. It is
similarly useful when mixed with black, and will be found advantageous
in rusty iron, as anchors, chains, &c. For the deepest and richest parts
of foregrounds it may be employed alone, as also for deep dark cracks
and fissures, or strong markings in other near objects, as boats and
figures. With French blue, or cobalt and white, a set of beautiful warm
or cold grays may be obtained, in proportion as the brown or blue
predominates. Compounded with blues and bright yellows such as aureolin,
it gives fine autumnal russet greens. A good purple for soft aerial
clouds is furnished by cobalt and brown madder, or for stormy clouds
by the brown, Prussian blue, and black: an equally good slate colour
is obtained from cobalt, sepia, and the brown. For glazing over foliage
and herbage, a mixture of the madder with aureolin or gamboge is adapted;
and for brooks and running streams compounds of this brown with raw Sienna,
cobalt and raw Sienna, Vandyke brown, and French blue, will each be found
useful. Black sails are well represented by burnt Sienna, French blue, and
brown madder; and red sails by light red or burnt Sienna with the brown.

277. MIXED MARRONE.

Marrone is a retiring colour easily compounded in all its hues and
shades by the mixture variously of red, and black or brown; or of any
other warm colours in which red and black predominate. A reference to
the permanent brown, black, and red or reddish pigments will show to
what extent the colour marrone may safely be produced by admixture. In
compounding marrone, the brown or black may be itself compounded, before
the addition of the red, reddish-purple, or russet, requisite for its
conversion.

       *       *       *       *       *

278. _Chica Marrone_.

Chica, the red colouring principle alluded to in the ninth chapter, is
extracted from the _Bignonia chica_, by boiling its leaves in water,
decanting the decoction, and allowing it to cool, when a red matter
falls down, which is formed into cakes and dried. Insoluble in cold
water, it dissolves in alcohol and alkalies; is precipitated from
alkaline solutions by acids without alteration; and is bleached by
chlorine. Another variety of the same substance, obtained from Para in
Brazil, and known as crajuru, carajuru, or caracuru, behaves in a
similar manner. This is said to be superior to the former sort.

A chica pigment, brought from South America, and examined by the author,
was of a soft powdery texture, and rich marrone colour. Somewhat
resembling Rubens' madder in hue, it was equal in body and transparency
to the carmine of cochineal, though by no means approaching it in
beauty, or even in durability. Simply exposed to the light of a window,
without sun, the colour was soon changed and destroyed. Conclusive
evidence as this is that the sample submitted to Mr. Field was
worthless, it remains to be seen whether all the colours to be derived
from chica, by different modes and from different kinds, are equally
valueless as pigments.

279. _Chocolate Lead_,

or Marrone Red, is a pigment prepared by calcining oxide of lead with
about a third of copper oxide, and reducing the compound to a uniform
tint by levigation. It is of a chocolate hue, strong opaque body, and
dries freely. Like all lead and copper colours, it is blackened by
impure air.

280. _Cobalt Marrone._

There is obtainable from cobalt a very rich marrone brown, which, like
many other colours, is more beautiful while moist than when dried.
Permanent, if carefully made and most thoroughly washed, it is an
expensive compound, and must rank among those colours which are
interesting in the laboratory but superfluous in the studio.

281. _Madder Marrone_,

or Marrone Lake, was a preparation of madder, of great depth,
transparency, and stability. Working well in water, glazing and drying
in oil, and in every respect a good pigment, it was one of those colours
which gradually--and often, as in this case, unfortunately--become
obsolete, on account of their hues being easily given by admixture of
other pigments. There was likewise a deeper kind, called Purple Black. A
good madder marrone may be produced by adding to brown madder either
rose madder, madder carmine, or Rubens' madder, with a slight portion of
black or blue if required.

282. _Mars Marrone._

Under the heading of a New Marrone Pigment there appeared some months
back in a chemical journal the following:--"The blood-red compound
obtained by adding a soluble sulphocyanide to a salt of iron in solution
can be made (apparently at least) to combine with resin thus: To a
concentrated solution of sesquichloride of iron and sulphocyanide of
potassium in ether, an etherial solution of common resin is added, and
the whole well shaken together. There is then mixed with it a
sufficiency of water to cause a precipitate, when it will be found,
after the mixture has stood a few hours, that the whole or nearly the
whole of the red-coloured iron compound has united with the precipitated
resin, forming the marrone-coloured pigment in question. When this
coloured substance is finely powdered and mixed with water, the liquid
is not the least coloured; whence it is inferred that the red iron
compound has chemically united itself with the resin."

The foregoing account is rather to be regarded as of scientific interest
than of practical utility. The blood-red solution of sulphocyanide of
iron is in itself not stable: when the red solution of this salt is so
exposed to the sun, that the rays pass through the glass jar containing
it, it is rendered colourless, but the colour is retained or restored
when the rays pass directly from the air into the fluid; so that when a
properly diluted solution is placed in a cylindrical glass vessel in
direct sunshine, it loses colour in the morning till about eleven in the
forenoon, when the rays beginning to fall upon the surface exposed to
the air, gradually restore the colour, which attains its maximum about
two o'clock. Moreover, the solution is immediately decolourised by
sulphuretted hydrogen and other deoxidizing agents, as well as by
alkalies and many acids. It is scarcely probable that the union of the
red colouring matter with the resin would suffice to secure it from
change; and there is little doubt that the new marrone pigment would be
a chameleon colour.

       *       *       *       *       *

Failures in the process of burning carmines, and preparing the purple of
gold, frequently afford good marrones. Compounds more or less of that
hue are likewise furnished by copper, mercury, &c. Some ochres incline
to marrone when calcined: indeed we have remarked in many instances that
the action of fire anticipates the effects of long continued time; and
that several of the primary and secondary colours may, by different
degrees of burning, be converted into their analogous secondary,
tertiary, or semi-neutral colours.

The one marrone or brown-marrone pigment at present employed, brown
madder, is permanent.

FOOTNOTES:

[B] This was written previous to the opening of the new rooms of the
Royal Academy at Burlington House. In these, among other improvements,
the subject of wall space has been considered.




CHAPTER XIX.

ON THE SEMI-NEUTRAL, GRAY.


Of the tribe of semi-neutral colours, GRAY is third and last, being
nearest in relation to black. In its common acceptation, and that in
which we here use it, gray, as was observed in the third chapter,
denotes a class of cool cinereous colours faint of hue; whence we have
blue grays, olive grays, green grays, purple grays, and grays of all
hues, in which blue predominates; but no yellow or red grays, the
prevalence of such hues carrying the compounds into the classes of brown
and marrone, of which gray is the natural opposite. In this sense the
_semi-neutral_ Gray is distinguished from the _neutral_ Grey, which
springs in an infinite series from the mixture of the neutral black and
white. Between gray and grey, however, there is no intermediate, since
where colour ends in the one, neutrality commences in the other, and
vice versâ. Hence the natural alliance of the semi-neutral
gray--definable as a cool coloured grey--with black or shade; an
alliance which is strengthened by the latent predominance of blue in the
synthesis of black, so that in the tints resulting from the mixture of
black and white, so much of that hue is developed as to give apparent
colour to the tints. This explains why the tints of black and dark
pigments are colder than their originals, so much so as in some
instances to answer the purposes of positive colours. It accounts in
some measure for the natural blueness of the sky, yet not wholly, for
this is in part dependent, by contrast, upon the warm colour of sunshine
to which it is opposed; for, if by any accident the light of nature
should be rendered red, the colour of the sky would not appear purple,
in consequence, but green. Again, if the sun shone green, the sky would
not be green, but red inclined to purple; and so would it be with all
colours, not according to the laws of composition, but of contrast;
since, if it were otherwise, the golden rays of the sun would render a
blue sky green.

The grays are the natural cold correlatives, or contrasts, of the warm
semi-neutral browns, as well as degradations of blue and its allies.
Hence blue added to brown throws it into or toward the class of grays,
and hence grays are equally abundant in nature and necessary in art: in
both they comprehend a widely diffused and beautiful play of retiring
colours in skies, distances, carnations, and the shadowings and
reflections of pure light, &c. Gray is, indeed, the colour of space, and
has therefore the property of diffusing breadth in a picture, while it
furnishes at the same time good connecting tints, or media, for
harmonizing the general colouring. Consequently the grays are among the
most essential hues of the art, though they must not be suffered to
predominate where the subject or sentiment does not require it, lest
they cast over the painting that gloom or leaden dulness reprobated by
Sir Joshua Reynolds; yet in solemn works they are wonderfully effective,
and proper ruling colours. Nature supplies these hues from the sky
abundantly and effectively throughout landscape, and Rubens has employed
them as generally to correct and give value to his colouring, with fine
natural perception in this branch of his art: witness his works in the
National Gallery, and in that of the Luxembourg.

According to the foregoing relations, grays favour the effects and force
of warm colours, which in their turn also give value to grays. It is
hence that the tender gray distances of a landscape are assisted,
enlivened, and kept in place by warm and forcible colouring in the
foreground, gradually connected through intermediate objects and middle
distances by demi-tints declining into gray; a union which secures full
value to the colours and objects, and by reconciling opposites gives
repose to the eye. As a general rule, it may be inferred that half of a
picture should be of a neutral hue, to ensure the harmony of the
colouring; or at least that a balance of colour and neutrality is quite
as essential to the best effect of a painting as a like balance of light
and shade.

283. MINERAL GRAY,

or Mineral Gr_e_y, as it is often improperly spelt, is obtainable from
the lapis lazuli, after the blue and ash have been worked out. So
derived, it is a refuse article, worthless if the stone has been
skilfully exhausted of its ultramarine. As this is now generally the
case, the best mineral gray is no longer a waste product, but a lower
species of ash, a pale whitish blue with a grey cast. Possessing the
permanence of ultramarine, it may be regarded in colour as a very weak
variety of that blue, diluted with a large quantity of white slightly
tinged by black. A pigment peculiar to oil painting, it is admirably
adapted to that gray semi-neutrality, the prevalence of which in nature
has been just remarked. For misty mornings, cloudy skies, and the like,
this gray will be found useful.

284. MIXED GRAY

is formed by compounding black and blue, black and purple, black and
olive, &c.; and is likewise produced by adding blue in excess to madder
brown, sepia, &c., transparent mixtures which are much employed. It
should be borne in mind that the semi-neutrals, like the secondaries and
tertiaries, may be so compounded as to be permanent, semi-stable, or
fugitive. The due remembrance of this cannot be too strongly insisted
upon, seeing that in every picture the browns and grays are of frequent
occurrence. These it is that lend such charm to the whole, flowing, as
it were, like a quiet under-current of colour beneath the troubled
surface of more decided hues. In the work of every true artist--between
whom and the mere painter there is as much difference as between the
poet and the poetaster--there is sentiment as well as colour, whether
the subject be an exciting battle-scene or a bit of still life. This
sentiment, as strongly felt as the colour is clearly seen, is imparted
in no small degree by the skilful use of semi-neutrality, the
compounding of which, as time goes on, will therefore affect a picture
for good or for evil.

Subjoined is an analysis of the three semi-neutrals, which serves partly
to show in what great variety they may be obtained by admixture.

    Brown   = Black                 + Yellow }
       "    =   "                   + Orange }   + Red, Purple, &c.
       "    =   "                   + Citrine}
       "    = 2 Yellow              + Red        + Blue
       "    = 2 Orange              + Green      + Purple
       "    = 2 Citrine             + Russet     + Olive
    Marrone = Black                 + Red
       "    =     "                 + Purple-red
       "    =     "                 + Russet
       "    = 2 Red       }
       "    = 2 Purple-red}         + Dark Brown or Black
       "    = 2 Russet    }
    Gray    = Black + Blue       }
       "    =   "   + Purple-blue}  + 2 White
       "    =   "   + Olive      }
       "    = 2 Blue       }
       "    = 2 Purple-blue}        + Light Brown, or Black + 2 White
       "    = 2 Olive      }

In the last division, the White has been added to remind the reader that
grays are coloured greys, not coloured blacks; and are therefore faint
of hue. This paleness, however, need not necessarily be produced by
admixture with white: it can be gained by means of thin washes. As a
pigment, gray may be to all appearance black in bulk.

285. NEUTRAL TINT,

or, more correctly, _Semi_-Neutral Tint, is a compound shadow colour of
a cool character. It is permanent, except that on exposure the gray is
apt to become grey, a change which may be prevented by a slight addition
of ultramarine ash. So protected, it becomes serviceable in landscape
for the extreme distance, which, it may be laid down as a general
principle, should be painted rather cold than otherwise. Blue being the
principal compound of atmosphere, it is of the utmost importance to
obtain this in the first instance, particularly as, from its being only
of a blue tint, not blue colour, it is so immediately altered and acted
upon by subsequent washes; whereas, the blue tone once lost, it will be
found very difficult to be recovered. Wherever a picture is wanting in
air effect, the cause will, upon examination, be seen to rest entirely
upon the absence of pure grays, bordering upon a bluish tone, not
tending, be it observed, to brown or purple. A bluish gray, then, of
rather a cold tone, such as the neutral tint, is recommended as the
prevailing hue with which to begin the extreme distances; and, as a
rule, it is better to pass with this over as much of the landscape as
possible, and thus lay the foundation for a general atmosphere.

286. PAYNE'S GRAY

resembles the preceding in being a compound colour and liable to assume
a grey cast by time, but differs from it in having more lilac in its
hue, and being therefore of a warmer tone. Giving by itself a clear
violet shadow, it may be rendered more neutral by a small portion of
burnt Sienna, an admixture which, whether the gray or Sienna
predominates, affords useful tints. Compounded with light red or Vandyke
brown, the gray is good for shipping and sails, or the stems and
branches of trees; while with gamboge or aureolin it is suited to glossy
leaves in high light, also to very cold tones in foregrounds, herbage,
&c. Yellow ochre, light red, and Payne's gray form a mixture for banks
and roads; the ochre, gray, and sepia, a most beautiful tint for stones;
and brown madder and the gray, a fine shade for the black head and feet
of cattle. Alone, the gray is serviceable for slate; and compounded with
light red, for bricks or tiles in shadow.

287. ULTRAMARINE ASH

is obtained from the stone after the richer and more intense blue has
been extracted. Although not equal in beauty, and inferior in strength
of colour to ultramarine, it is a valuable bye-product varying in shade
from light to dark, and in hue from pale azure to cold blue. With a grey
cast, it affords delicate and extremely tender tints, not so positive as
ultramarine, but which, as water-colours, wash much better. It furnishes
grays softer, purer, and more suited to the pearly tints of flesh,
skies, distances, foliage, shadows of drapery, &c. than those composed
of other blues, with white and black, which the old masters were wont to
employ. Ultramarine, however, produces the same effects when broken with
black and white, and is thus sometimes carried throughout the colouring
of a picture. The ash, compounded with lamp black, gives a soft cold
gray for dark louring clouds, or for twilight away from the sun's
influence. Alone it is adapted to very remote hills or mountains, and
with orient yellow or aureolin to distant foliage.

       *       *       *       *       *

The native phosphate of iron, which has been already described in the
tenth chapter under its name of Blue Ochre, might have been classed
among the grays, being similar in colour to the deeper hues of
ultramarine ashes. Powdered slate, slate clays, and several native
earths, likewise rank with grays; but some of the earths we have tried
are not durable, being apt to become brown by the oxidation of the iron
they contain. It may be proper here to mention those other pigments,
known as tints, which, being the result of the experience of accredited
masters in their peculiar modes of practice, serve to facilitate the
progress of their amateur pupils, while they are more or less eligible
for artists. Such are _Harding's_ and _Macpherson's Tints_, composed of
pigments which associate cordially, and sold ready prepared in cakes and
boxes for miniature and water painting.

Of the four grays in use--mineral gray, ultramarine ash, neutral tint,
and Payne's gray--the two first are quite unchangeable, and the others
sufficiently stable to be classed as permanent.




CHAPTER XX.

ON THE NEUTRAL, GREY.


Grey is the second and intermediate of the neutral colours, standing
between _white_ and _black_. True or normal grey is only obtainable by
admixture of pure white with pure black, various proportions of which
afford numerous tones of pure grey. In practice it may likewise be
produced by a thin wash of black over white. The neutral gr_e_y differs
from the semi-neutral gr_a_y in not being coloured by any primary,
secondary, tertiary, or semi-neutral; hence any blue, purple, olive, or
gray added to it, at once destroys the neutrality of grey, and converts
it into gray. Thus easily defiled and changed in class, grey is rather a
theoretical than a practical colour. To our knowledge, there has never
been a true grey pigment, that is, one composed exclusively of pure
white and pure black; the gr_a_ys known to the palette as Mineral Grey
and Payne's Grey having been incorrectly named. Practically, the nearest
approach to a normal grey is furnished by Black Lead, which forms grey
tints of greater permanence and purity than the blacks in general use,
and is now employed for this purpose with approved satisfaction by
experienced artists.

Being compounded of white and black, grey partakes in some measure of
the qualities of both those colours--for colours, as a matter of
convenience, they must be called; although white is often spoken of as
no colour, and black as the complete extinction of all colour. With
white predominant, grey is used, pure or coloured, for the general
lights of a picture; just as, with black predominant, grey is employed,
pure or coloured, for the shades. It helps to subdue the absolute white,
and to make the absolute black conspicuous. Black and white are in some
respects complementary to each other, and when in contact, appear to
differ more from each other than when viewed separately: both show with
best effect when harmonised by a medium of grey, normal or otherwise.
The primary colours, also, gain in brilliancy and purity by the
proximity of grey. With dark colours, such as blue and violet, and deep
tones in general, grey forms assortments of analogous harmonies; while
with the luminous colours, such as red, orange, yellow, and the light
tints of green, it forms harmonies of contrast. Although grey never
produces a bad effect in its assortments with two luminous colours, in
most cases the association is dull and inferior to black and white. The
only instance in which grey associates with two such colours more
happily than white is that with red and orange. Grey is inferior to both
white and black with red and green, red and yellow, orange and yellow,
orange and green, yellow and green; and is not so good as white with
yellow and blue. In association with sombre colours, such as blue and
violet, and with broken tones of luminous colours, grey gives rise to
harmonies of analogy which have not the vigour of those with white; but
if the colours do not combine well together, it has the advantage of
separating them from each other. Associated with two colours, one
sombre, the other luminous, grey will perhaps be better than white, if
white produces too strong a contrast of tone: on the other hand, grey
will be preferable to black, if that has the inconvenience of increasing
too much the proportion of sombre colours. Grey associates more happily
than black with orange and violet, green and blue, or green and violet.

288. MIXED GREY.

When a ray of solar light (a sunbeam) is passed through a prism of flint
glass, and the image or 'prismatic spectrum' received upon a screen of
white paper, it is found to consist of numerous rays of different
colours, which are conveniently divided into six groups--red, orange,
yellow, green, blue, violet. Optically, the union of red, yellow, and
blue, in proper proportions, constitutes white light; whether the rays
of the three separate colours are mixed, or of one with the other two in
combination: the same result ensues when red is mixed with green as if
it were mixed with blue and yellow, because green is composed of blue
and yellow. Consequently, any primary mixed with a secondary composed of
the other two primaries, forms the complement of rays necessary to
constitute or make up white light, and vice versâ.

There is, however, a very great difference between the results arising
from the mixture of the pure coloured rays of the spectrum, and those
from material colours or pigments. When, by means of a convex lens, we
reunite the coloured rays of the spectrum white light is reproduced; but
when we mix coloured materials, blues, yellows, and reds, the compound
is never white, but grey or black; even if these coloured pigments are
taken in the exact proportions in which their colours exist in the
spectrum. Ultramarine, our purest blue, reflects red rays as well as
blue rays; aureolin, our purest yellow, reflects blue as well as yellow
rays; and carmine reflects yellow as well as red rays. Now whenever the
third primary colour is present in any mixture of coloured materials, it
tends to form grey, by mixing with a sufficient quantity of the other
coloured rays to neutralize it, and the presence of this grey breaks or
tarnishes the pure colour. Hence it is that to obtain a pure green, a
blue should be taken tinged with yellow rather than with red, and a
yellow tinged with blue: if there were chosen either a blue or a yellow
tinged with red, this latter colour would go to form some grey in the
compound, which would tarnish the green. In like manner, to produce pure
orange, neither the red nor the yellow must contain blue; and similarly
with pure purple, neither the blue nor red should contain yellow.

As regards pigments, then, a proper mixture of yellow, red, and blue; or
of yellow and purple, red and green, or blue and orange; or of orange,
green, and purple, affords black if sufficiently intense, and grey if
sufficiently diluted. The black may be rendered grey by spreading a thin
wash over a white ground, or by the direct addition of white. It must be
remembered, however, that suitable proportions of the component colours
are essential. When all three of the primaries, for example, are mixed
together, colour is neutralised according as they are compounded of
equal strength and in right quantities: if proper proportions are
observed, pure black or normal grey results; but if not, there will be
produced a coloured black or a coloured grey, an excess of one or two of
the primaries giving rise to brown, marrone, or gray.

A reference to the lists of permanent primary and secondary pigments
will show to what extent durable greys can be compounded. As these
pigments differ so widely in hue and other properties, no fixed rules
can be given for their admixture: to ensure neutrality, practice and a
correct eye are indispensable. Without perfect neutrality, difficult to
attain and rarely to be met with, grey ceases to exist. In pure white,
pure grey, and pure black, colour is, so to speak, conspicuous by its
absence.




CHAPTER XXI.

ON THE NEUTRAL, BLACK.


Black is the last and lowest in the series or scale of colours
descending--the opposite extreme from white--the maximum of colour. To
be perfect, it must be neutral with respect to colours individually, and
absolutely transparent, or destitute of reflective power as regards
light; its use in painting being to represent shade or depths, of which
black is the element in a picture and in colours, as white is of light.

As there is no perfectly pure and transparent black pigment, black
deteriorates all colours in deepening them, as it does warm colours by
partially neutralizing them, but it combines less injuriously with cold
colours. Though black is the antagonist of white, yet added to it in
minute portion, it in general renders white more neutral, solid, and
local, with less of the character of light. Impure black is brown, but
black in its purity is a cold colour, and communicates a coolness to all
light colours; thus it _blues_ white, _greens_ yellow, _purples_ red,
and _cools_ blue. Hence the artist errs with ill effect who regards
black as of nearest affinity to hot and brown colours, and will do well
to keep in mind--"The glow of sunshine and the _cool_ of shade."

It is a fault of even some of our best colourists, as evinced by their
pictures, to be too fond of black upon their palettes, and thence to
infuse it needlessly into their tints and colours. With such it is a
taste acquired from the study of old pictures; but in nature hardly any
object above ground is black, or in daylight is rendered neutral
thereby. Black, therefore, should be reserved for a local colour, or
employed only in the under-painting properly called grounding and dead
colouring. As a local colour, black has the effect of connecting or
amassing surrounding objects, and is the most retiring of all colours, a
property which it communicates to other colours in mixture. It heightens
the effect of warm as well as light colours, by a double contrast when
opposed to them, and in like manner subdues that of cold and deep
colours. In mixture or glazing, however, these effects are reversed, by
reason of the predominance of cold colour in the constitution of black.
Having, therefore, the double office of colour and of shade, black is
perhaps the most important of all colours to the artist, both as to its
use and avoidance.

It may be laid down as a rule that the black must be conspicuous.
However small a point of black may be, it ought to catch the eye,
otherwise the work is too heavy in the shadow. All the ordinary shadows
should be of some _colour_--never black, nor approaching black, they
should be evidently and always of a luminous nature, and the black
should look strange among them; never occurring except in a black
object, or in small points indicative of intense shade in the very
centre of masses of shadow. Shadows of absolutely negative grey,
however, may be beautifully used with white, or with gold; but still
though the black thus, in subdued strength, becomes spacious, it should
always be conspicuous: the spectator should notice this grey neutrality
with some wonder, and enjoy, all the more intensely on account of it,
the gold colour and the white which it relieves. Of all the great
colourists, Velasquez is the greatest master of the black chords: his
black is more precious than other people's crimson. Yet it is not simply
black and white that must be made valuable, rare worth must be given to
each colour employed; but the white and black ought to separate
themselves quaintly from the rest, while the other colours should be
continually passing one into the other, being all plainly companions in
the same gay world; while the white, black, and neutral grey should
stand monkishly aloof in the midst of them. Crimson may be melted into
purple, purple into blue, and blue into green, but none of them must be
melted into black.

All colours are comprehended in the synthesis of black, consequently the
whole sedative power of colour is comprised in black. It is the same in
the synthesis of white; and, with like relative consequence, white
includes all the stimulating powers of colour in painting. It follows
that a little white or black is equivalent to much colour, and hence
their use as colours requires judgment and caution. By due attention to
the synthesis of black, it may be rendered a harmonizing medium to all
colours, to all which it lends brilliancy by its sedative effect on the
eye, and its powers of contrast: nevertheless, we repeat, it must be
introduced with caution when _hue_ is of greater importance than shade.
Even when employed as a shadow, without much judgment in its use, black
is apt to appear as local colour rather than as privation of light; and
black pigments obtained by charring have a tendency to rise and
predominate over other hues, subduing the more delicate tints by their
chemical bleaching power upon other colours, and their own disposition
to turn brown or dusky. For these reasons deep and transparent colours,
which have darkness in their constitution, are better adapted as a rule
for producing the true natural and permanent effects of shade. Many
pictures of the early masters, and especially of the Roman and
Florentine schools, evince the truth of our remarks; and it is to be
feared the high reputation of these works has betrayed their admirers
into this defective employment of black.

Black substances reflect a small quantity of white light, which receives
the complementary of the colour contiguous to the black. By
'complementary' is meant that colour which is required with another
colour to form white light; thus, green is the complementary of red,
blue of orange, and yellow of violet, or vice versâ; because green and
red, blue and orange, and yellow and violet, each make up the full
complement of rays necessary to form white light. Briefly digressing, we
give the following mode of observing complementary colours:--Place a
sheet of white paper on a table opposite to one of two windows admitting
diffused daylight[C] into a room; take a piece of coloured glass and so
place it that the coloured light transmitted through it falls over the
surface of the paper; then put an opaque object on the paper close to
the coloured glass. The shadow of this object will not appear black or
of the colour of the glass, as might be supposed, but of its
complementary colour; thus if the glass is red, the colour of the
shadow will be green, although the whole of the paper surrounding it
appears red. Similarly, if the glass is blue, the shadow will appear
orange; if it is green, the shadow will appear red; and so with other
colours. It is absolutely essential, however, to the success of this
experiment, that the paper be also illuminated with the white light
admitted from the other window.

It has been said that black substances reflect a small quantity of white
light, which receives the complementary of the colour contiguous to the
black. If this colour is deep, it gives rise to a luminous
complementary, such as orange, or yellow, and enfeebles the black; while
the other complementaries, such as violet or green, strengthen and
purify it. In colours associated with black, if green is juxtaposed
therewith, its complementary red, added to the black, makes it seem
rusty. Those colours which best associate with black are orange, yellow,
blue, and violet. It would be well to remember that black, being always
deeper than the juxtaposed colour, entails contrast of tone, and tends
to lower the tone of that colour.

Most of the black pigments in use are obtained by charring, and owe
their colour to the carbon they contain. As the objects of vegetal and
animal nature may be blackened through every degree of impurity by the
action of fire, black substances more or less fitted for pigments
abound. The following are the chief native and artificial black
pigments, or colours available as such:--

289. BLACK LEAD,

_Plumbago_, or _Graphite_, contains in spite of its name no lead, being
simply a species of carbon or charcoal. In most specimens iron is
present, varying in quantity from a mere trace up to five per cent,
together with silica and alumina. Sometimes manganese and titanic acid
are likewise found. It is curious that carbon should occur in two
distinct and very dissimilar forms--as diamond, and as graphite; one,
white, hard, and transparent; the other, black, soft, and opaque: the
artist, therefore, who uses a pigment of plumbago, paints with nothing
more or less than a black diamond. The best graphite, the finest and
most valuable for pencils, is yielded by the mine of Borrowdale, at the
west end of Derwent Lake, in Cumberland, where it was first wrought
during the reign of Elizabeth. A kind of irregular vein traverses the
ancient slate-beds of that district, furnishing the carbon of an
iron-grey colour, metallic lustre, and soft and greasy to the touch.
Universally employed in the form of crayons, &c. in sketching,
designing, and drawing, until of late years it was not acknowledged as a
pigment: yet its powers in this respect claim a place for it. As a
water-colour, levigated in gum in the usual manner, it may be
effectively used with rapidity and freedom in the shading and finishing
of pencil drawings, or as a substitute therein for Indian ink. Even in
oil it may be employed occasionally, as it possesses remarkably the
property of covering, forms very pure grey, dries quickly, injures no
colour chemically, and endures for ever. These qualities render it the
most eligible black for adding to white in minute quantity to preserve
the neutrality of its tint.

Although plumbago has usurped the name of Black Lead, there is another
substance more properly entitled to this appellation, and which may be
used in the same way, and with like effects as a pigment. This substance
is the sulphide of lead, found native in the beautiful lead ore, or
Galena, of Derbyshire. An artificial sulphide can be prepared by dry and
wet processes, which is subject to gradual oxidation on exposure to the
air, and consequent conversion into grey or white. Neither variety can
be compared to graphite for permanence, although the native is
preferable to the artificial.

Plumbago, or the so-called Black Lead, is often adulterated to an
enormous extent with lamp black.

290. BLUE BLACK,

_Charcoal_, _Liege_, or _Vine Black_, is a well-burnt and levigated
charcoal prepared from vine twigs, of weaker body than ivory or lamp
black, and consequently better suited to the grays and general mixed
tints of landscape painting, in which it is not so likely to look black
and sooty as the others may do. Of a cool neutral tint, it has, in
common with all carbonaceous blacks, a preserving influence on white
when duly mixed therewith; which it owes, chemically, to the bleaching
power of carbon, and, chromatically, to the neutralizing and contrasting
power of black with white. Compounded slightly with blue black, and
washed over with zinc white, white lead may be exposed to any ordinary
impure atmosphere with comparative impunity. It would be well for art if
carbon had a like power upon the colour of oils, but of this it is
deficient; and although chlorine destroys their colour temporarily, they
re-acquire it at no very distant period.

Alone, blue black is useful as a cool shade for white draperies; and
compounded with cobalt, affords a good gray for louring clouds.

291. BRITISH INK

is a compound black, preferred by some artists to Indian ink, on account
of its not being liable to wash streaky, as the latter does: at the same
time it is not so perfectly fixed on the paper as Indian ink.

292. INDIAN INK,

sometimes called _China_ or _Chinese Ink_, is chiefly brought from
China in oblong cakes, of a musky scent, ready prepared for painting in
water. Varying considerably in body and colour, the best has a shining
black fracture, is finely compact, and homogeneous when rubbed with
water, in which, when largely diluted, it yields no precipitate. Without
the least appearance of particles, its dry surface is covered with a
pellicle of a metallic appearance. When dry on the paper, it resists the
action of water, yet it will give way at once to that action, when it
has been used and dried on marble or ivory, a fact which proves that the
alummed paper forms a strong combination with the ink; possibly a
compound of the latter on an aluminous base, might even be employed in
oil. Different accounts are given of the mode of making this ink, the
principal substance or colouring matter of which is a smoke black,
having all the properties of our lamp black; the variety of its hues and
texture seeming wholly to depend on the degree of burning and levigating
it receives. From certain Chinese documents, we learn that the ink of
Nan-king is the most esteemed; and among the many sorts imported into
this country, we find those of the best quality are prepared with lamp
black of the oil of Sesame; with which are combined camphor, and the
juice of a plant named _Houng hoa_ to give it brightness of tone.
According to an analysis by M. Proust, the better kinds contain about
two per cent. of camphor. By some, the pigment known as Sepia has been
supposed to enter into their composition.

_Liquid Indian Ink_ is a solution for architects, surveyors, &c.

293. IVORY BLACK

is ivory charred to blackness by strong heat in closed vessels.
Differing chiefly through want of care or skill in preparing, when well
made it is the richest and most transparent of all the blacks, a fine
neutral colour perfectly durable and eligible both in water and oil.
When insufficiently burnt, however, it is brown, and dries badly; or if
too much burnt, it becomes cineritious, opaque, and faint in hue. With a
slight tendency to brown in its pale washes, this full, silky black is
serviceable where the sooty density of lamp black would be out of place.
It is occasionally adulterated with bone black, a cheaper and inferior
product.

Being nothing more nor less than animal charcoal, ivory or bone black
had best not be compounded with organic pigments, in water at least. It
is well known that this charcoal possesses the singular property of
completely absorbing the colour of almost any vegetal or animal
solution, and of rendering quite limpid and colourless the water charged
with it. If a solution of indigo in concentrated sulphuric acid be
diluted with water, and animal charcoal added in sufficient quantity,
the solution will soon be deprived of colour. The more perfect the ivory
or bone black, the more powerful is its action likely to be: either over
or under calcined, animal charcoal is less energetic; in the former
case, because it is less porous; in the latter, because the animal
matter, not being wholly consumed, makes a kind of varnish in the
charcoal which interferes with its acting. To a greater or less extent,
gums, oils, and varnishes serve similarly as preventives, thereby
decreasing the danger of employing these blacks in admixture; but, in
the compounding of colours, nothing is gained by needless risk. To mix
with organic pigments, therefore, blue or lamp blacks should be
substituted for those of ivory or bone; that is, vegetal charcoal should
be used instead of animal. It is a question whether even with inorganic
pigments the adoption of the former in admixture would not be advisable.
It was once the general opinion that the action of animal charcoal was
limited to bodies of organic origin, but it has since been found that
inorganic matters are likewise influenced. "Through its agency," says
Graham, "even the iodine is separated from iodide of potassium;" whence
probably pigments containing iodine would suffer by contact. The
investigation of Weppen appears to prove that the action of the charcoal
extends to all metallic salts; with the following, no doubt remains of
this being so, to wit:--the sulphates of copper, zinc, chromium, and
protoxide of iron; the nitrates of lead, nickel, silver, cobalt,
suboxide and oxide of mercury; the protochlorides of tin and mercury;
the acetates of lead and sesquioxide of iron; and the tartrate of
antimony. Whether animal charcoal exercises any deleterious influence on
pigments consisting of these metals, and, if so, how far and under what
circumstances, can only be answered when our knowledge of the properties
of pigments is greater than it now is. At present, perhaps, it is safer
to choose vegetal charcoal for mixed tints, inasmuch as, although it
shares the property of bleaching in a certain degree, it does not
possess the same energy.

294. LAMP BLACK,

or _Lamblack_, is a smoke black, being the soot procured by the burning
of resins or resinous woods. It is a pure vegetal charcoal of fine
texture, not quite so intense nor so transparent as the black made from
ivory, but less brown in its pale tones. It has a very strong body that
covers readily every underlay of colour, works well, but dries badly in
oil. On emergency, it may be prepared extemporaneously for
water-painting by holding a plate over the flame of a lamp or candle,
and adding gum to the colour: the nearer the plate is held to the wick
of the lamp, the more abundant and warm will be the hue of the black
obtained; at a greater distance it will be more effectually charred, and
blacker.

Mixed with French blue or cobalt, lamp black gives good cloudy grays,
which are useful for the shadows of heavy storm clouds. With French blue
and this black alone various beautiful stormy skies may be represented;
the contrast of the blue causing the black to assume, if desired, a warm
tone in shadows. For like purposes, the black with ultramarine ash
affords a very soft hue, and with light red and cobalt in different
proportions yields silvery tones most serviceable. To the dark marking
of murky and dirty clouds, a compound of lamp black and light red is
particularly suited; while a mixture of the black with cobalt and purple
madder is adapted for slate-coloured sunset and sunrise clouds. French
blue softened with a little lamp black is fitted for mountains or hills,
very remote; and the same blue and black with rose madder meet their
tints if nearer. In seas the black is useful with raw Sienna and other
colours; while, whether in storm or calm, vessels and boats may be
painted with tints of lamp black, madder brown, and burnt Sienna,
varying in degrees of strength according to the distances. Lamp black
alone, or with French blue, cobalt and purple madder, emerald green, or
rose madder, is good for rocks; and for dark foreground objects when
mixed with madder lake and burnt Sienna. With aureolin the black
furnishes a sober olive for foliage, and with rose madder a fine colour
for the stems and branches of trees. Compounded with light red, it is
suited to the first general tones of the ground for banks and roads; and
with yellow ochre or madder red, to parts of buildings and cattle. A
very eminent miniature painter recommends for hair tints, lamp black,
Indian red, and burnt Sienna. Being a dense solid colour, this black
must be used sparingly to avoid heaviness.

Hitherto confined to painting and engraving, lamp black has lately
refuted the assertion that there is nothing new under the sun by making
its appearance in photography. By a method which combines the fidelity
of that art with the permanence of prints, there is produced a species
of photographic engraving, so to speak, having lamp black or carbon for
its colouring matter. Indeed, in this 'Autotype' process, as it is
called, any other durable pigment or pigments may be used, and a
photographic picture thus obtained. In copying the works of artists,
especially, the mode promises to be of value, inasmuch as by its agency
the same pigments may be made the colouring matter of the reproduction
as are employed in the original. If this be in sepia or bistre, the copy
can be autotyped in those colours; or if a red chalk drawing be required
to be multiplied, the proofs may be in red chalk, the copy when
produced to the same scale being scarcely distinguishable from the
original. In like manner, any single colour of the artist's palette is
applicable without restriction or limitation, so that not only are every
line and touch rendered absolutely, but the very pigment used in the
original is found in the copy. Moreover, as the pigments are quite
unchanged by the action of the other agents employed, the resulting
colour of the print is determined once for all, just as the artist mixes
those pigments on his palette for his picture. As extending the use of
lamp black and permanent pigments in general, this brief digression on
Autotypography may be pardoned in a treatise on colours.

295. MIXED BLACK.

Black is to be considered as a synthesis of the three primary colours,
the three secondaries, or the three tertiaries, or of all these
together; and, consequently, also of the three semi-neutrals, and may
thus be composed of due proportions of either tribe or triad. All
antagonistic colours, or contrasts, likewise afford the neutral black by
composition; but in all the modes of producing black by compounding
colours, blue is to be regarded as its archeus or predominating colour,
and yellow as subordinate to red, in the proportions, when their hues
are true, of eight blue, five red, and three yellow. It is owing to
this predominance of blue in the constitution of black, that it
contributes by mixture to the pureness of hue in white colours, which
usually incline to warmth, and that it produces the cool effect of
blueness in glazing and tints, or however otherwise diluted or dilated.
It accords with the principle here inculcated that in glass-founding the
oxide of manganese, which gives the _red_ hue, and that of cobalt, which
furnishes the _blue_, are added to brown or _yellow_ frit, to obtain a
velvety black glass. Similarly the dyer proceeds to dye black upon a
deep blue basis of indigo, with the ruddy colour of madder and the
yellow of quercitron, &c.

Some of the best blacks and neutrals of the painter are those formed
with colours of sufficient power and transparency upon the palette.
Prussian blue and burnt lake afford a powerful though not very durable
black; and compound blacks in which transparent pigments are employed
will generally go deeper and harmonize better with other colours than
any original black pigment alone. Hence lakes and deep blues, added to
the common blacks, greatly increase their clearness and intensity: in
mixture and glazing of the fine blacks of some old pictures, ultramarine
has evidently been used. In this view, black altogether compounded of
blue with red and yellow, each deep and transparent, and duly
subordinated according to its powers, will give the most powerful and
transparent blacks; although, like most other blacks, they dry badly in
oil. Of course, as with all compound colours, it depends entirely on the
pigments employed whether these mixed blacks are permanent or not: a
compound black can very well pass through the stages of black to grey,
gray, or dirty white, if each link in the chain of combination be not as
strong as its fellows.

       *       *       *       *       *

296. _Black Chalk_

is an indurated clay, of the texture of white chalk, and chiefly used
for cutting into crayons. Fine specimens have been found near Bantry in
Ireland, and in Wales, but the Italian has the most reputation. Crayons
for sketching and drawing are also artificially prepared, which are
deeper in colour and free from grit. Wood charcoal is likewise cut into
crayons, that of soft woods, such as lime, poplar, &c., being best
adapted for the purpose.

297. _Black Ochre_,

Earth Black, or Prussian Black, is a native earth, combined with iron
and alluvial clay. It is found in most countries, and should be washed
and exposed to the atmosphere before being employed. Sea-coal, and
other black mineral substances, have been and may be used as substitutes
for the more perfect blacks, when the latter are not procurable, which
now seldom or never happens.

298. _Bone Black_,

obtained by charring, is similar to that of ivory, except that it is a
little warmer in tone, having a reddish or orange tinge, and is a worse
drier in oil. Like ivory black, it is very transparent. Immense
quantities of bone black are consumed with sulphuric acid in the
manufacture of shoe blacking.

299. _Coffee Black_,

though little known and not on sale, has been strongly recommended by
Bouvier as one of the best blacks that can be used. Soft without being
greasy, light, almost impalpable, even before being ground, it gives
tints of a very bluish gray when mixed with white, a quality precious
for making the blues of the sketch, and dull greens. It is said to dry
better than blue or vine black, and to combine admirably with other
colours. De Montabert prefers calling it Coffee Brown, giving it as an
exemplification of a bluish-brown, but probably this brown hue is owing
to want of skill in its manufacture. We have not had personal experience
of the colour, but there is no theoretical reason why a carbonaceous
black should not be produced from coffee. The mode of proceeding is to
calcine the berry in a covered vessel, and well wash the resulting
charcoal with boiling water by decantation. In order to prevent the
powder, which is of great lightness, from floating, it is made into
paste with a few drops of alcohol before adding the water.

300. _Frankfort Black_

is said to be made of the lees of wine from which the tartar has been
washed, by burning, in the manner of ivory black; although the inferior
sort is merely the levigated charcoal of woods, of which the hardest,
such as box and ebony, yield the best. Fine Frankfort black, though
almost confined to copper-plate printing, is one of the best black
pigments extant, being of a neutral colour, next in intensity to lamp
black, and more powerful than that of ivory. Strong light has the effect
of deepening its colour. It is probable that this was the black used by
some of the Flemish painters, and that the pureness of the greys formed
therewith is due to the property of charred substances of preventing
discolourment.

301. _Manganese Black_,

the common black oxide of that metal, is the best of all blacks for
drying in oil without addition. It is also a colour of vast body and
tingeing power. As a siccative, it might be advantageously employed with
ivory black.

302. _Mineral Black_

is a native impure carbon of soft texture, found in Devonshire. Blacker
than plumbago, and free from its metallic lustre, it is of a neutral
colour, greyer and more opaque than ivory black, and forms pure neutral
tints. Being perfectly durable, and drying well in oil, it is of value
in dead colouring on account of its solid body, as a preparation for
black and deep colours before glazing. It would likewise be the most
permanent and best possible black for frescoes.

303. _Paper Black_,

a pigment unknown to the modern palette, like most of our numbered
italicised colours, is of the nature of blue or vine black. Very soft
and of a fine bluish-gray, it is fitted for flesh, or for mixing with
whites or yellows in landscapes.

304. _Peach Black_,

or Almond Black, made by burning the stones of fruits, the shell of the
cocoa-nut, &c., is a violet-black, once much used by Parisian artists.
Bouvier believes it to be a good black, but at the same time sensibly
asks, of what use is it to have a black of this cast, which can always
be given by lake, without diminishing but rather increasing the
intensity of the black it may be mixed with.

305. _Prussian Black._

The same Prussian blue which gives a brown when burnt in the open air,
yields a black when calcined in a close crucible. Very intense, very
soft and velvety, and very agreeable to work, this bluish-black dries
much more promptly than most other blacks, and scarcely requires
grinding. On account of its extreme division, however, it would probably
be found more energetic as a decolourising agent in admixture with
organic pigments than most carbonaceous blacks.

Another Prussian black, containing copper, and made by a wet process, is
obtained when a dilute solution of cupric sulphate and ferrous sulphate,
in proper proportions, is mixed with a quantity of ferrocyanide of
potassium not in excess. A very bulky deep black precipitate is formed,
which is difficult to wash, and is deep black when dry. It is insoluble
in water, and appears to be a compound analogous to Prussian blue. As a
pigment, this black is inferior to the preceding.

306. _Purple Black_

is, or rather was, a preparation of madder, of a deep purple hue
approaching black. Powerful and very transparent, it glazed and dried
well in oil, and was a durable and eligible pigment. Its tints with
white lead were of a purple cast.

307. _Spanish Black_,

or Cork Black, is a soft black, obtained by charring cork, and differs
not essentially from Frankfort black, except in being of a lighter and
softer texture. "Some of my friends," says Bouvier, "call it _Beggars'
Ultramarine_, because it produces, by combinations, tints almost as fine
as ultramarine." A blue but not a velvet black, where intensity is
required some other is to be preferred. For mixtures, however, it is
stated to be admirable, and especially for linen, skies, distances, and
the various broken tints of carnations, &c.

       *       *       *       *       *

Besides those blacks which have been mentioned, there are others
furnished by several of the metals and by many organic substances
employed as dyes; but as the blacks in common use are all permanent, and
have been found sufficient for every purpose, it is scarce needful to
swell the list. Nor is it more needful, the Editor considers, to swell
the book; lest his aim be defeated of reflecting in a _moderate_-sized
mirror the palette as it is and might be at the present day. Arrived at
age, as it were, in its twenty-first chapter, this treatise may fitly
conclude with Black, the last of the series of colours. Let us hope the
maxim of Sir Joshua Reynolds, that success in some degree was never
denied to earnest work may apply here.

Still, by way of finale, we would offer a few remarks. In no branch of
the science, perhaps, is it more hazardous to commit oneself to a
positive dictum than in the chemistry of colours, so liable are theory
and practice to clash, and so often does the experience of one person or
one time differ from that of another. He who has turned his attention to
pigments, finds nearly every assertion must be qualified, for to nearly
every rule there is some exception, and learns that theory alone may
mislead. For example, a colour known to be fugacious may last, in
certain cases, a surprisingly long time; while, on the contrary, a
pigment permanent when used alone, may be rendered fugitive by improper
compounding. Again, what holds good of a colour produced by one process,
or employed in one vehicle or by one artist, may not be true of the same
colour made by a different mode, or used in another vehicle or by
another artist. It is because, then, colours are of every degree of
durability, from the perfectly stable to the utterly fugitive, and
because each one is liable to influence by every condition of time,
place, and circumstance, that the chemist's theory is opposed as often
to the painter's practice as the experience of artists themselves
varies. This may explain the charges of inconsistency and contradiction
which have been brought against writers on pigments, faults that lie
rather with the nature of the subject than with the authors.

Even at the risk of being tiresome, we have throughout insisted on the
choice of permanent pigments, not simply for use alone but for mixed
tints. To quote Cennini, "I give you this advice, that you endeavour
always to use ... good colours.... And if you say that a poor person
cannot afford the expense, I answer, that if you work well (and give
sufficient time to your works), and paint with good colours, you will
acquire so much fame that from a poor person you will become a rich one;
and your name will stand so high for using good colours, that if some
masters receive a ducat for painting one figure, you will certainly be
offered two, and your wishes will be fulfilled, according to the old
proverb, 'good work, good pay.'" Of a truth, if man cannot dip his brush
in the rainbow and paint with the aerial colours of the skies, he can at
least select the best pigments that earth and the sea afford him;
preferring, where he cannot get brilliancy and permanence combined,
sobriety and permanence to brilliancy and fugacity. It must be the wish
of every real artist to leave behind him a lasting record of his skill,
a permanent panorama of those hues of nature which in life he loved so
well. To effect this, genius alone is powerless: there must be first a
proper choice of materials, and next a proper use of them. The painter's
pigments are the bricks wherewith the mortar of his mind must be mixed,
either to erect an edifice that shall endure for ages, or one which will
quickly topple over like a house of cards. Now in nothing more than in
painting is prevention better than cure--indeed cure may be said to be
here out of the question: for good or for evil a picture once painted is
painted for ever. Without a strong constitution there is no hope for it;
no chemistry can strengthen the sickly frame, restore the faded colour,
stop the ravages of consumption: Science stands helpless before dying
Art.

And yet, she sighs to think, it might have been otherwise. If durable
pigments had been employed, if her counsel had been sought, this need
not have been. In the history of modern art the use and abuse of colours
would furnish a sad chapter, telling of gross ignorance, and a grosser
indifference. Happily there is promise of a healthier state of things.
When this comes, Art will be less shy to consult her sister: in the
interests of both there should be closer union. Without waiting till the
picture is finished--for then it will be too late--let her, if in doubt,
frankly display the contents of her palette and ask advice. Now, not
knowing what pigments are chosen or how they are used, never standing
by and watching the progress of the work, how can Science lend her aid?
She would willingly, for she herself needs help: at present her
knowledge is limited, not so much of the chemistry of colours as of the
properties of pigments. She seeks to mix her pound of theory with an
ounce of practice, and craves a warmer welcome to the studio. For any
approximation to the truth to be arrived at, facts must be noted with
the conditions under which they occur, not by one sister alone nor by
the other alone, but by both. In future, Art and Science should go hand
in hand, mutually dependent on each other, mutually trustful of each
other, working with and for each other, earnestly and patiently.

FOOTNOTES:

[C] Light is either direct or diffused--direct, when the sun's rays fall
upon any object; diffused, when ordinary daylight illumines objects with
white light, causing them to appear of their peculiar colours.




ADDENDUM.

With the present rapid progress of applied chemistry, an addendum in a
work of this kind is quite excusable. Even while the book is being
printed some fact may be announced which the author or editor would wish
to insert. In our case this has happened. Very recently there has been
introduced in France as a pigment

308. TUNGSTEN WHITE,

or _Tungstate of Baryta_. "At the request of a landscape painter," says
M. Sacc in a letter to M. Dumas, "I was induced to examine in succession
all our insoluble white compounds, with regard to their adaptability to
painting purposes. Tungstate of baryta answers perfectly, covers as well
as white lead, and is as unalterable as zinc white. It has been employed
by this artist for three months, and was found equally successful in oil
or water colours, chromolithography, and even in making white
impressions on a black ground. This harmless substitute for the
injurious white lead is prepared on a large scale in Paris by M. E.
Rousseau." We have not met with a sample of that gentleman's
manufacture, but judging from our own specimens, made both by wet and
dry processes, and carefully tried in water and oil, it would seem that
a perfect white pigment has yet to be discovered. With us, at least,
tungstate of baryta is far from having the body of white lead, and
indeed is inferior in opacity to good zinc white. Unaffected by foul
air, the tungstate appears to possess the common fault of all whites
when compared with white lead--want of body, moreover it is a bad dryer.
However, M. Rousseau's preparation may not be open to these objections,
and we therefore reserve our final opinion of tungsten white. It is
intended to publish from time to time a fresh edition of Field's
Chromatography, and we hope in the next issue to give a more detailed
and favourable account of the new pigment.




INDEX.


A.

Acacia catechu, 354.

Academy, Royal, at Burlington House, 365.

Acetate of lead, as a siccative, 51.
  "        improper use of, 52.

Adulteration, 70.
  "  of Anotta, 256.
  "     Artificial Ultramarine, 214.
  "     Black Lead, 394.
  "     Cadmium Yellow, 88.
  "     Carmine, 134.
  "     Chrome Yellow, 94.
  "     Cochineal, 132.
  "     Genuine Ultramarine, 214.
  "     Indigo, 202.
  "     Ivory Black, 397.
  "     Madder, 140.
  "     Madder Carmine, 142.
  "     Mars Yellow, 102.
  "     Prussian Blue, 203.
  "     Red Lead, 152.
  "     Smalt, 198.
  "     Verdigris, 276.
  "     Vermilion, 156.
  "     Veronese Green, 268.
  "     White Lead, 70, 74, 75.
  "     Yellow and Orange Orpiment, 113, 259.
  "     Zinc White, 77.

Advancing and retiring colours, 186-188.

Advice, Cennini's, 411.

Aerial perspective, 22.

African cochineal, 170.
  "     green, 271.

Air and light, action of, on pigments, 39.

Air effect, want of, 378.

Albumen, 50.

Alchemy, 259.

Alexander the Great, 296.
  "       Veronese, 284.

Alkanet, 302.

Almagra, 147.

Almond Black, 407.

American artist, an, 347.

Analysis of Brown, 377.
  "         Citrine, 329.
  "         Gray, 377.
  "         Marrone, 377.
  "         Olive, 330.
  "         Russet, 330.

Anchusa tinctoria, 302.

Ancients, colouring of the, 3.
  "       colours of the, 5, 6, 218.

Aniline, 162.
  "      colours, 162.
  "        "      cakes of, 163.
  "        "      in oil, 247.

Animal Æthiops, 348.
  "    charcoal, 397-399.
  "    jelly, 50.

Anotta, 255.

Antimony, Golden Sulphur of, 256.
  "       Orange, 256.
  "       Red, 159.
  "       White, 79.
  "       Yellow, 105.

Antipathies of pigments, 193.

Antwerp Blue, 207.
  "     Brown, 339.

Apelles, 7, 293.

Archil, 303.
  "     Purple, 303.

Arethas, 217.

Armenian blue, 5, 217, 228.
  "      bole, 147.
  "      stone, 228.

Arsenical pigments, 273.

Arsenic green, substitutes for, 288, 290.
  "     white, 79.
  "     yellow, 116.

Art and Science, 238, 412.

Artificial Ultramarine, 209-216.
  "        acid pigments with, 214.
  "        adulteration of, 215.
  "        green in, 211.
  "        gum with, 214.

Artificial Ultramarine, in siliceous painting, 212.
  "        origin of, 209.
  "        prize for, 209.
  "        test for, 212.

Artists and painters, 182.

Arts, Society of, 130.

Ash, Ultramarine, 379.

Ashes, Blue, 228.

Asphaltic Lake, the, 337.

Asphaltum and Asphalt, 337.
  "       Liquid, 339.

Association of Science, British, 357.

Assyrians, colouring and colours of, 6.

Augustus Cæsar, 295.

Aureolin, 42, 47, 83-87.
  "       Chemical News on, 84.
  "       in admixture, 86.
  "       Mr. Aaron Penley on, 85.
  "       the purest yellow, 84, 384.

Aurine, 162.

Autotype process, the, 401.

Avignon, berries of, 312.

Axiom, a wholesome, 201.

Axioms for compounding, 250.

Azuline, 162.

Azure, 192, 196, 217.


B.

Barff, Mr., 212.

Barium and Bismuth chrome greens, 280.

Barthe and Laurent, MM., 235.

Bartholomew, Mr., 143.

Baryta, Ferrate of, 165.
  "     Silicate of, 290.

Barytic White, 65.

Beauty in Pigments, 46.

Beeswax, 50.

Berries, French, Persian, and Turkey, 212.

Berzelius, 169.

Bice, Green, 187.

Bignonia chica, 367.

Bismuth Purple, 304.

Bixa Orellana, 255.

Bixine, 256.

Black, 27.
  "    ancient, 5.
  "    as a colour, 387, 391.
  "    as a pigment, 389.
  "    colours with, 392.
  "    on the Neutral, 387.

BLACK PIGMENTS:--
  Almond Black, 407.
  Beggars' Ultramarine, 409.
  Black Chalk, 404.
  Black Lead, 382, 393.
  Black Ochre, 404.
  Blue Black, 394.
  Bone Black, 405.
  British Ink, 395.
  Charcoal Black, 394.
  Chinese Ink, 395.
  Coffee Black, 405.
  Copper Prussian Black, 408.
  Cork Black, 409.
  Earth Black, 404.
  Frankfort Black, 406.
  Galena, 394.
  Graphite, 393.
  Indian Ink, 395.
  Ivory Black, 397.
  Lamp Black, 399.
  Liege Black, 394.
  Manganese Black, 406.
  Mineral Black, 407.
  Mixed Black, 402.
  Paper Black, 407.
  Peach Black, 407.
  Plumbago, 393.
  Prussian Black, 404, 408.
  Purple Black, 408.
  Spanish Black, 409.
  Vine Black, 394.

Bladder Green, 282.

Blanc d'Argent, 71.

Blending of pigments, 37.

Blood, Dragon's, 137.

Bloodstone, 147.

Blue, 28.
  "   ancient, 5, 217.
  "   Armenian, 5, 217.
  "   as a colour, 183.
  "   contrast of, 185, 188.
  "   discordant, 185.
  "   on the Primary, 183.

BLUE PIGMENTS:--
  Antwerp Blue, 207.
  Artificial Ultramarines, 209-216.
  Azure, 192, 217.
  Basic Prussian Blue, 207.
  Berlin Blue, 203, 207.
  Bice, 228.
  Bleu de Garance, 209.
  Blue Ashes, 228.
  Blue Bice, 228.
  Blue Carmine, 228.
  Blue Ochre, 226, 380.
  Blue Sand, 196.
  Blue Verditer, 228.
  Brilliant Ultramarine, 215.
  Cerulian Blue, or Coeruleum, 190.
  Cobalt Blue, 192.
  Cobalt Blues, 189-199.
  Cobalt Prussian Blue, 227.
  Cobalt Ultramarine, 192.
  Coëlin, 190.
  Copper Blues, 227-230.
  Cotton Seed Blue, 230.
  Cyanine, 198.
  Dumont's Blue, 196.
  Dutch Ultramarine, 189.
  Enamel Blue, 189.
  Egyptian Blue, 229.
  Factitious Ultramarine, 215.
  Ferricyanide of Iron, 208.
  Ferrocyanide of Iron, 203.
  French Blue, 215.
  French Ultramarine, 215.
  Genuine Ultramarine, 216-225.
  Gmelin's German Ultramarine, 209.
  Gold Blue, 231.
  Guimet's Ultramarine, 209.
  Haerlem Blue, 207.
  Hungary Blue, 189.
  Indian Blue, 199.
  Indicum, 199.
  Indigo, 199.
  Intense Blue, 202.
  Iodine Blue, 231.
  Iridium Blue, 232.
  Iris, 228.
  Lazuline, 217.
  Lazulite Blue, 217.
  Lazurstein, 217.
  Leitch's Blue, 199.
  Leithner's Blue, 189.
  Manganese Blue, 232.
  Mineral Blue, 207.
  Mountain Blue, 228.
  Native Prussian Blue, 207.
  Native Ultramarine, 216.
  Natural Ultramarine, 216.
  New Blue, 216.
  Outremer, 217.
  Outremer de Guimet, 209.
  Paris Blue, 192, 203.
  Permanent Blue, 216.
  Platinum Blue, 233.
  Powder Blue, 196.
  Prussian Blue, 203.
  Prussiate of Iron, 203.
  Pure Ultramarine, 217.
  Real Ultramarine, 216.
  Reboulleau's Blue, 230.
  Royal Blue, 196.
  Saunders' Blue, 230.
  Saxon Blue, 189.
  Schweinfurt Blue, 230.
  Smalt, 195-198.
  Terre Bleu, 228.
  Thénard's Blue, 192.
  True Ultramarine, 216.
  Tungsten Blue, 233.
  Turnbull's Blue, 208.
  Ultramarines, 209-225.
  Verditer, 228.
  Vienna Blue, 192.
  Wood-Tar Blue, 233.
  Zaffre, 189.
  Zinc-Cobalt Blue, 235.

Body White, 72.

Bole, Armenian, 147.

Borrowdale, 393.

Bouvier, 153, 345, 347, 355, 405, 407, 409.

Box, the painter's, 60.

Bradley, Mr., 246.

British School, 9.

Broken colours, 16.

Bronze, 279.

Brown, 28.
  "    analysis of, 377.
  "    as a colour, 335.
  "    Citrine, 317.
  "    contrast of, 337.
  "    Liquid, Prout's, 345.
  "    Madder, 305.
  "    Mars, 313.
  "    on the Semi-Neutral, 334.

BROWN PIGMENTS:--
  Animal Æthiops, 348.
  Antwerp Brown, 339.
  Asphaltum or Asphalt, 337.
  Bistre, 340.
  Bitumen, 339.
  Bitumen of Judea, 337.
  Bone Brown, 340.
  Burnt Umber, 341.
  Cadmium Brown, 353.
  Caledonian Brown, 341.
  Campania Brown, 352.
  Cappah Brown, 342.
  Cassel Earth, 343.
  Castle Earth, 343.
  Catechu Browns, 374.
  Chalon's Brown, 344.
  Chestnut Brown, 357.
  Chrome Browns, 355.
  Cologne Earth, 344.
  Copper Brown, 355.
  Cory's Madder or Yellow Madder, 353.
  Cullen's Earth, 344.
  Egyptian Brown, 347.
  Euchrome, 342.
  French Prussian Brown, 355.
  Gambogiate of Iron, 357.
  Hypocastanum, 357.
  Iron Browns, 357.
  Ivory Brown, 340.
  Jew's Pitch, 337.
  Leitch's Brown, 346.
  Manganese Brown, 358.
  Mineral Brown, 342.
  Mineral Pitch, 337.
  Mixed Brown, 346.
  Mummy, 347.
  Mummy Brown, 347.
  Nickel Brown, 358.
  Ochre Browns, 358.
  Prussian Brown, 348.
  Purple Brown, 359.
  Roman Sepia, 351.
  Rubens' Brown, 359.
  Sepia, 348.
  Terre de Cassel, 343.
  Uranium Brown, 360.
  Vandyke Brown, 351.
  Verona Brown, 353.
  Warm Sepia, 350.
  Yellow Madder, 353.
  Zinc Brown, 360.

Brown Pink, 312.
  "   Red, 147.
  "   Spanish, 146.
  "   Stil de Grain, 312.

Browns, abundance of, 336, 361.

Brun de Mars, 313.

Brunswick Green, 271, 279.

Brushes, soap and alkali in, 52.

Burlington House, Royal Academy at, 365.

Burnt Carmine, 298.
  "   Lake, 298.
  "   Madder, 305.
  "   Orpiment, 259.
  "   Roman Ochre, 255.
  "   Sienna, 243.
  "   Terra di Sienna, 243.
  "   Verdigris, 331.


C.

Cadmium Brown, 353.
  "     Orange, 36, 42, 244.
  "     Red, 42, 130.
  "     White, 78.
  "     Yellow, 87, 92.
  "       "     adulteration of, 88.
  "       "     manufacture of, 92.
  "       "     when fugacious, 92.
  "       "     with White Lead, 89.

Caledonian Brown, 341.

Campania Brown, 352.

Camphor, 396.

Cappah or Cappagh Brown, 342.

Carajuru, 367.

Carbolic acid, 162.

Carbon, 393.

Carmichael, Mr., 348.

Carmine, 133, 135.
  "      adulteration of, 134.
  "      Blue, 225.
  "      Burnt, 298.
  "      Field's, 142.

Carmine, Madder, 142.
  "      manufacture of, 134.
  "      Vermilion, 156.
  "      Violet, 302.
  "      with Indian Yellow, 98.
  "        "  White Lead, 134.

Carnac, ruins at, 4.

Carnagione, 149.

Carthamus, 174.

Cartoons at Hampton Court, 10.

Cassel Earth, 343.
  "    Green, 288.
  "    Terre de, 343.
  "    Yellow, 121.

Cassius, Purple of, 306.

Cassius's Purple Precipitate, 306.

Castle Earth, 343.

Catechu Browns, 354.

Celandine, 96.

Cendres Bleues, 230.

Cennini, advice of, 411.

Cerulian Blue or Coeruleum, 190.

Ceruse, 74.

Chalk, Black, 404.
  "    Green, 173.
  "    Red, 172.
  "    White, 79.

Chalon's Brown, 344.

Chaptal, Count, 105, 229.

Charcoal, animal, 397, 399.
  "       Black, 394.
  "       vegetal, 398, 406.

Charles I., 220.

Charred blacks, 390, 395, 406.

Cheese, anotta in, 256.

Chemical News, extract from, 84.

Chestnut Brown, 357.

Chevreul, M., 173, 191, 205, 364.

Chiaroscuro, 15.

Chica d'Andiguez, 160.
  "   Marrone, 367.
  "   Red, 159.

China, Mandarins of, 219.
  "    White, 80.

Chinese Ink, 395.
  "     Lake, 137.
  "     Orange, 246.
  "     Rouge, 174.
  "     Vermilion, 156.
  "     White, 75.
  "     Yellow, 111.

Chinoline, 162.

Chocolate Lead, 368.

Chromate of Mercury, 256.

Chromates of lead, organic pigments with, 248, 280.

Chrome Arseniate, 284.
  "    Browns, 355.
  "    Green, True, 267.
  "    Greens, 279-281.
  "    Ochre, 267.

Chrome Orange, 248.
  "    Oxide, 267.
  "    Oxides, 266-271.
  "    Red, 151.
  "    Scarlet, 151.
  "    Yellows, 93-95.
  "      "      adulteration of, 94.

Chromium, Green Oxide of, 267.
  "       Opaque Oxide of, 267.
  "       Oxide of, 267.
  "       Transparent Oxide of, 268.

Church, Professor, 165.

Cicero, 296.

Cinnabar, 153.
  "       Green, 280.

Citrine, 28.
  "      analysis of, 329.
  "      as a colour, 310.
  "      contrast of, 311.
  "      on the Tertiary, 310.

CITRINE PIGMENTS:--
  Brown Pink, 312.
  Brown Stil de Grain, 312.
  Brun de Mars, 313.
  Cassia Fistula, 316.
  Citrine Brown, 317.
  Citrine Lake, 312.
  Mars Brown, 313.
  Mixed Citrine, 314.
  Quercitron Lake, 312.
  Raw Umber, 315.
  Umber, 315.

Citron Yellow, 95.

Classes of Colours, on, 27-30.

CLASSIFIED PIGMENTS:--
  Black, 409.
  Blue, 236.
  Brown, 361.
  Citrine, 319.
  Gray, 380.
  Green, 291.
  Grey, 386.
  Marrone, 371.
  Olive, 333.
  Orange, 261.
  Purple, 308.
  Red, 181.
  Russet, 324.
  White, 80.
  Yellow, 125.

Claude, 345.

Cleanliness in painting, 53.

Coal-Tar Colours, 160-164, 247.
  "               cakes of, 163.
  "               in oil, 247.

Cobalt Blue, 192.
             chalkiness in, 195.
             manufacture of, 192.
  "    Blues, 189-199.
  "    Green, 285.
  "    Marrone, 368.
  "    Prussian Blue, 227.
  "      "      Green, 282.
  "    Purples, 305.
  "    Ultramarine, 192.

Coccus (Abies nigra), 168.
  "    cacti, 131.
  "    ficus, 138.
  "    ilicis, 153, 167.

Cochineal, 132.
  "        adulteration of, 132.
  "        Dr. Warren de la Rue on, 132.
  "        lake, with Vermilion, 136.
  "        Lakes, 131-137.

Coëlin, 190.

Coeruleum, 190, 198, 217, 229.

Coffee Black, 405.
  "    Brown, 405.

Cohesion and colour, 197, 208.
  "      durability, 197, 208.

Cologne Earth, 344.
  "     Yellow, 94.

Colour and neutrality, 375.
  "    latent, 58.
  "    of extreme light objects, 21.
  "    of shadow, 21.
  "    on the Relations and Harmony of, 13.

Coloured rays, mixture of, 384.

Colouring, ancient, 3-7.
  "        false, 20.
  "        importance of, 10-12.
  "        on, 3.
  "        vicious, 11-21.

Colours, ancient, 5, 6, 218.
  "      and Pigments Individually, on, 57.
  "      broken, 16.
  "      classes of:--
  "        "          Neutral, 27.
  "        "          Primary, 28.
  "        "          Secondary, 28.
  "        "          Semi-Neutral, 29.
  "        "          Tertiary, 28.
  "      complementary, 391.
  "      discordant, 17, 185.
  "      entire, 28.
  "      extreme, 28.
  "      fugacity of ancient, 6.
  "      held in check, 106.
  "      hot and cold, 20.
  "      imaginary, 115.
  "      individual beauty of, 57.
  "      light and dark, 30.
  "      material, mixture of, 384.
  "      mixture and compounding of, 17-19.
  "      not obtainable, 114.
  "      not pigments, 305.
  "      perspective of, 22.

Colours, retiring or advancing, 186-188.
  "      superfluous, 124.
  "      unfitted for pigments, 115, 180.
  "      vitrified, 33, 197.
  "      with black, 27, 392.
  "        "  colours, 27.
  "        "  grey, 382.
  "        "  white, 27, 63.

Common pigments, 359.

Compounding colours, on, 242-252, 277.

Compound pigments, 36.

Constable, 265.

Constantinople, 7.

Constant White, 65.
  "      free acid in, 66.

Contrast of colour and neutrality, 15.
  "      gradations and extremes, 19.
  "      hues, 13-15.
  "      shades, 15.
  "      warmth and coolness, 15.

Copper Blues, 227-230.
  "    Borate, 285.
  "    Brown, 355.
  "    Chrome, 286.
  "    Greens, 271-276.
  "    Prussian Black, 408.
  "    Prussiate of, 323.
  "    Reds, 164.
  "    Smalt, 220.
  "    Stannate, 286.
  "    Yellow, 116.

Cork Black, 409.

Correggio, 8, 335.

Cory's Madder or Yellow Madder, 119, 353.

Cotton Seed Blue, 230.

Cremnitz or Crems White, 72.

Crimson Lake, 135.

Crookes, Mr., 260.

Crowding of pictures, 364.

Cudbear, 303.

Cullen's Earth, 344.

Cuttle Fish, 348.

Cuyp, 136.

Cyanine, 198.

Cyanus, 198, 217.


D.

Damonico, 257.

Darkening of mineral colours, 284.

Davy, Sir H., 229.

Dead Sea, the, 337.

Deep Cadmium, 87.
  "  Chrome, 93.
  "  Vermilion, 154.
  "  Deoxidation of pigments, 38.

Detractors of modern pigments, 43-45.

Dewint's Green, 330.

Diagram, 89.

Diesbach, M. 203.

Dilution of colour, 34.

Di Palito, 109.

Direct and diffused light, 391.

Discord of colours, 17, 185.

Disinfectants of the palette, 359.

Distance, law about, 188.

Distilled Verdigris, 276.

Distinction of colours, 318, 320.

Dominichino, 8.

Dragon's Blood, 137.
  "      with White Lead, 138.

Drop Gum, 96.

Drying of pigments, 50.
  "    oils, lead in, 121.

Duffield, Mrs., 144.

Dumas, M., 234, 414.

Dumont's Blue, 196.

Durability of pigments, 31-45, 46.

Dussance, Professor H., 175.

Dutch Pink, 100.
  "   Schools, 8.
  "   the, 156, 200.
  "   Ultramarine, 189.
  "   White, 74.

Dyeing, brown for, 318.
  "     orange for, 257.

Dyes and pigments, 169.


E.

Earth Black, 404.
  "   Burnt Sienna, 243.
  "   Cassel, or Castle, 343.
  "   Cologne, 344.
  "   Cullen's, 344.
  "   Green, 283.
  "   Raw Sienna, 113.

Egg-shells, white of, 80.

Egypt, catacombs of, 347.
  "    temples of Upper, 5, 217.

Egyptian Blue, 229.
  "      Brown, 347.

Egyptians, the, colouring and colours of, 3-5.

Elizabeth, Queen, 393.

Eisner's Green, 286.

Emerald Green, 271.

Emeraldine, 162.

Enamel Blue, 189.
  "    colours, 33, 197.

England, climate and females of, 9.

English Green, 280.
  "     Pink, 100.
  "     Red, 149.
  "     Vermilion, 146.

Entire colours, 28.

Equations, 329, 330, 377.

Euchrome, 342.

Exhibition, International, of 1862, 244, 354.

Experiment, 213.

Exposure of pigments, 38.

Extract of Gamboge, 97.
  "     Vermilion, 157.

Extreme colours, 28.


F.

Factitious Indigo, proposed, 202.
  "        Ultramarine, 215.

Falsalo, 341.

Fast and fugitive, pigments both, 38.

Ferrate of Baryta, 165.

Ferricyanide of Iron, 208.

Ferrocyanide  "  203.

Field's Carmine, 142.
  "     Lakes, 139-145.
  "     Orange Vermilion, 158.
  "     Purple, 301.
  "     Russet, 321.

Fineness of texture in pigments, 50.

Fire, action of, on pigments, 371.
  "   pigments affected by, 40.

Fistula, Cassia, 316.

Flake White, 72.

Flemish painters, 406.
  "     Schools, 8, 37.
  "     White, 72.

Florentine Lake, 137.
  "        painters and painting, 7, 8, 10, 391.

Flower pieces, background tint for, 279.

Foul air, ochres with, 359.

Frankfort Black, 406.

French berries, 312.
  "    Blue, 215.
  "    Green, 271.
  "    Prussian Brown, 355.
  "    Purple, Solid, 304.
  "    Ultramarine, 215.
  "    Veronese Green, 268.
  "    White, 71.

Fresco, Prussian Blue in, 206, 281.

Fruit pieces of W. Hunt, 315.

Fugacity of pigments, 31-45.

Fugitive colours, 34.


G.

Gainsborough, 20.

Galena, 394.

Galleries, picture, 363-365.

Gallstone, 95.

Gamboge, 96.
  "      as a glaze, 97.
  "      extract of, 97.

Gamboge Orange, 257.

Gambogiate of Iron, 357.

Garance, Bleu de, 209.

Gas, effect of, on colours, 191.

Gelbin's Yellow, 117.

General Qualities of Pigments, on the, 46.

Genuine Ultramarine, 216-225.
  "     adulteration of, 224.
  "     colouring matter of, 224.
  "     defects in, 222.
  "     manufacture of, 220.
  "     price of, 220.
  "     properties of, 221.
  "     tests for, 224.

Giallolino, 103.

Gilpin, 351.

Giovanni Bellini, 7.

Giulio Romano, 11.

Glazing of colours, 18.

Gloucestershire, 109.

Gmelin, M., 178, 210, 218, 227.

Gmelin's German Ultramarine, 209.

Gold Blue, 231.
  "  Purple, 306.
  "  Reds, 166.
  "  size, japanner's, 51.

Golden Sulphur of Antimony, 256.
  "    Yellow, 256.

Gradation in art, 328.
  "       nature, 326.

Graham, Mr., 398.

Graphite, 393.

Gray, 29, 372.
  "   analysis of, 277.
  "   and grey, 29, 372, 381.
  "   as a colour, 372, 374.
  "   as a pigment, 377.
  "   contrast of, 373.
  "   on the Semi-Neutral, 372.

GRAY PIGMENTS:--
  Mineral Gray, 375.
  Mixed Gray, 377.
  Neutral Tint, 377.
  Payne's Gray, 378.
  Ultramarine Ash, 379.

Greeks, colouring of the, 7, 8.
  "     the, 153, 167, 296.

Green, 28.
  "    as a colour, 263, 265.
  "    contrast of, 263.
  "    Dewint's, 330.
  "    discordant, 265.
  "    Olive, 330.
  "    on the Secondary, 263.

GREEN PIGMENTS:--
  African Green, 271.
  Barium Chrome Green, 280.
  Bismuth Chrome Green, 280.
  Bladder Green, 282.
  Bronze, 279.
  Brunswick Green, 271, 279.
  Chrome Arseniate, 284.
  Chrome Greens, 279-281.
  Chrome Oxide, 267.
  Chrome Oxides, 266-271.
  Cobalt Green, 285.
  Cobalt Prussian Green, 282.
  Copper Borate, 285.
  Copper Chrome, 286.
  Copper Greens, 271-276, 285-287, 288.
  Copper Stannate, 286.
  Distilled Verdigris, 276.
  Elsner's Green, 286.
  Emerald Green, 271, 283.
  English Green, 280.
  French Green, 271.
  French Veronese Green, 268.
  German Mineral Green, 288.
  Green Bice, 287.
  Green Cinnabar, 280.
  Green Earth, 283.
  Green Lake, 288.
  Green Ochre, 287.
  Green Oxide of Chromium, 267.
  Green Ultramarine, 287.
  Green Verditer, 287.
  Holy Green, 283.
  Hooker's Green, 281.
  Hungary Green, 274.
  Imperial Green, 271.
  Iris Green, 282.
  Malachite Green, 274.
  Manganese Green, 288.
  Marine Green, 271.
  Mineral Green, 288.
  Mitis Green, 271.
  Mixed Green, 277.
  Molybdenum Green, 289.
  Mountain Green, 274.
  Native Green, 267.
  Olympian Green, 271.
  Opaque Oxide of Chromium, 267.
  Oxide of Chromium, 267.
  Patent Green, 271.
  Persian Green, 271.
  Pickle Green, 276.
  Prussian Greens, 281.
  Quinine Green, 289.
  Rinman's Green, 285.
  Roman Green, 290.
  Sap Green, 282.
  Saxon Green, 271.
  Sheele's Green, 272.
  Schweinfurt Green, 271.
  Silicate of Baryta, 290.
  Swedish Green, 272.
  Terre Verte, 283.
  Titanium Green, 290.
  Transparent Oxide of Chromium, 268.
  True Chrome Green, 267.
  True Prussian Green, 281.
  Uranium Green, 291.
  Vanadium Green, 291.
  Venetian Green, 283.
  Verde Vessie, 282.
  Verdetto, 283.
  Verdigris, 276.
  Verona Green, 283.
  Veronese Green, 268.
  Vert de Zinc, 285.
  Vienna Green, 271.
  Viride Æris, 276.
  Viridian, 269.
  Zinc Green, 285.

Green, pure, to obtain, 277.

Greens, ancient, 5.

Grey, 28-30, 372.
  "   and gray, 29, 381.
  "   as a colour, 381.
  "   as a pigment, 382.
  "   colours with, 382, 383.
  "   on the Neutral, 381.

GREY PIGMENTS:--
  Black Lead, 382.
  Mixed Grey, 384-386.

Grinding of pigments, 37.

Guido, 8.

Guimet, M., 210, 215.
  "     Outremer de, 209.

Guimet's Ultramarine, 209.

Gum, Drop, 96
  "  tragacanth, 66.

Gyges, 7.


H.

Haerlem Blue, 207.

Hamburgh Lake, 137.
  "      White, 74.

Hampton Court, cartoons at, 10.

Harding's Tint, 380.

Harmony of colour, 13-24.

Hatching of colours, 18.

Haydon, 293.

Hercules Tyrius, 296.

Holy Green, 283.

Hooker's Green, 281.

Houng hoa, 396.

Hues, 27, 30.

Hungary Blue, 189.
  "     Green, 274.

Hunt, W., 315.

Hypocastanum, 357.


I.

Illumination, Cadmium Orange in, 246.
  "           Coal-Tar Colours in, 163, 247.
  "           Manual of, 246.
  "           Viridian in, 270.

Imperial Green, 271.

Indian Blue, 199.
  "    Ink, 349, 395.
  "    Lake, 138.
  "    Ochre, 146.
  "    Purple, 298.
  "    Red, 148.
  "    Yellow, 98.

Indicum, 199.

Indigo, 199.
  "     adulteration of, 202.
  "     possible substitute for, 235.
  "     proposed Factitious, 202.

Indigofera, 200.

Indium Yellow, 117.

Individually, on Colours and Pigments, 57.

Ink, blue, 207.
  "  British, 395.
  "  Chinese, 395.
  "  green, 276.
  "  Indelible Brown, 345.
  "  Indian, 395.
  "  Liquid Indian, 397.
  "  red, 145.

Inkfish, the, 348.

Innoxious pigments, 53.

Intense Blue, 202.
  "       "   manufacture of, 202.

International Exhibition of 1862, 244, 354.

Invisible Green, 329.

Iodine, 118.
  "     Blue, 231.
  "     Pink, 166.
  "     Scarlet, 150.
  "     Yellow, 118.

Iridium Blue, 232.

Iris, 228.
  "   Green, 282.

Iron Browns, 357.
  "  Ferricyanide of, 208.
  "  Ferrocyanide of, 203.
  "  Gambogiate of, 357.
  "  pigments affected by, 39, 90, 145, 147, 149, 150, 249.
  "  Prussiate of, 203.
  "  Smalt, 218.
  "  Yellow, 102, 118.

Italian Greens, 276, 277.
  "     Pink, 100.

Italics, numbered colours in, 114, 407.

Italy, colouring in modern, 8.

Ivory Black, 397.
  "     "    with Manganese Black, 407.

Ivory Brown, 340.


J.

Japanner's gold size, 51.

Jaune de Cologne, 94.
  "    " Fer, 102.
  "    " Mars, 102.
  "   Minérale, 94.

Jew's Pitch, 337.

Judea, Bitumen of, 337.


K.

Kermes, 153.
  "     Lake, 167.
  "     Mineral, 159.

Key of colouring, 40.

Khair tree, the, 354.

King's Yellow, 111.

Knowledge of pigments, 43, 44.

Kremnitz or Krems White, 72.

Kremser White, 75.


L.

Lac, 138, 167.
  "  Lake, 138.

Lake, Asphaltic, the, 337.
  "   Burnt, 198.
  "   Chinese, 137.
  "   Citrine, 312.
  "   Crimson, 135.
  "   Drop, 131.
  "   Florentine, 137.
  "   Green, 288.
  "   Hamburgh, 137.
  "   Indian, 138.
  "   Kermes, 167.
  "   Liquid Madder, 145.
  "   Madder, 144.
  "   Marrone, 369.
  "   Olive, 331.
  "   Orange, 258.
  "   Purple, 137.
  "   Quercitron, 100, 312.
  "   Roman, 137.
  "   Scarlet, 136.
  "   Venetian, 137.
  "   Yellow, 100.

Lakes, Cochineal, 131-137.
  "    Field's, 139-145.
  "    Madder, 139-145.
  "    Rubric, 139-145.
  "    Yellow, 99, 100.

Lamblack, 399.

Lamp Black, 399.

Lapis Lazuli, 209, 217, 219.

Laque de garance, 142.
  "   Minérale, 258.

Latent colour, 58.

Lawson, Professor, 168.

Lawson's Red, 168.

Layard, Mr., 6, 218.

Lazuline, 217.

Lazulite Blue, 217.

Lazur, Persian and Tartarian, 228.

Lazurium, 217.

Lazurstein, 217.

Lead, acetate or sugar of, 50-52.
  "   Black, 382, 393.
  "   carbonate of, 68.
  "   Chocolate, 368.
  "   dicarbonate of, 69.
  "   hydrated oxide of, 68.
  "   in drying oils, 121.
  "   Orange, 258
  "   oxychloride of, 73.
  "   pigments affected by, 39, 67, 97, 99, 112, 120, 134, 138, 139, 152, 201, 206, 248, 280, 312, 341.
  "   pigments, avoidance of, 67.
  "   Red, 151.
  "   Sulphate of, 72.
  "   White, 67-70.
  "   Whites, 67-75.

Leitch's Blue, 199.
  "      Brown, 346.

Leithner's Blue, 189.

Lemon Cadmium, 91.
  "   Yellow, 101.

Leonardo da Vinci, 8.

Leyden, Cassius of, 306.

Lichens, 304.

Liege Black, 394.

Light and air, pigments affected by, 91, 92, 95, 97, 98, 99, 112, 124, 134, 135, 136, 139, 151, 163, 199, 201, 205, 208, 247, 276, 282, 298, 303, 313, 330, 340, 343.

Light, direct and diffused, 391.
  "    electric, the, 191.
  "    magnesium, the, 191.
  "    Red, 149.

Likes and dislikes of pigments, 194.

Lime, pigments affected by, 40, 97, 98, 206, 275, 281.
  "   with Prussian Blue, 206, 281.

Linear perspective, 22.

Linseed oil with White Lead, 69.

Liquid Asphaltum, 339.
  "    Indian Ink, 397.
  "    Madder Lake, 145.
  "    Prout's Brown, 345.
  "    Rubiate, 145.

Lists of Permanent Pigments:--
  "   Blue, 278, 300.
  "   Green, 315, 329.
  "   Orange, 315, 323.
  "   Purple, 323, 329.
  "   Red, 253, 300.
  "   Yellow, 252, 278.

Litharge, 51, 120.

Litmus, 303.

Local colour, 24.

Lombard School, 8.

London White, 73.


M.

Macpherson's Tint, 380.

Madder, 139.
  "     adulteration of, 140.
  "     Brown, 365.
  "     Burnt, 305.
  "     Carmine, 142.
  "       "      adulteration of, 142.
  "     colouring matters of, 140.
  "     Cory's or Cory's Yellow, 119, 353.
  "     Dr. Schunck on, 140.
  "     Lake, 144.
  "     Lakes, 139-145.
  "       "    manufacture of, 141.
  "     Liquid Lake, 145.
  "     Orange, 258, 353.
  "     Pink, 144.
  "     Purple, 301.
  "     reds in oil, 144.
  "     Rose, 143.
  "     Rubens', 321.
  "     Yellow, 118, 353.

Magenta, 162.

Majolica, 146.

Malachite Green, 274.

Manganese as a siccative, 51, 77, 406.
  "       Black, 406.
  "       Blue, 232.
  "       Brown, 358.
  "       Green, 288.
  "       Red, 168.

Manufacture of Cadmium Yellow, 92.
  "         Carmine, 134.
  "         Cobalt Blue, 192.
  "         Intense Blue, 202.
  "         Vermilion, 92, 153.

Marine Green, 271.

Marrone, 28.
  "      analysis of, 377.
  "      as a colour, 362.
  "      contrasts of, 362.
  "      for walls of picture galleries, 363.
  "      on the Semi-Neutral, 362.

MARRONE PIGMENTS:--
  Brown Madder, 365.
  Chica Marrone, 367.
  Chocolate Lead, 368.
  Cobalt Marrone, 368.
  Madder Marrone, 369.
  Marrone Lake, 369.
  Marrone Red, 368.
  Mars Marrone, 369.
  Mixed Marrone, 367.
  Purple Black, 369.

Mars Brown, 313.
  "  Brun de, 313.
  "  colours named after, 102, 146.
  "  Orange, 248.
  "  Red, 145.
  "  Rouge de, 145.
  "  Violet, 290.
  "  Violet de, 290.
  "  Yellow, 102.

Massicot, 120.

Mastic varnish, 50.

Mauve, 163.

Mercury, Chromate of, 256.
  "      marrone, 371.
  "      white, 79.

Mérimée, 121, 142, 229, 284, 316,  343.

Metallic whites, 79.

Metals, rare, 172.

Michael Angelo, 8.

Mineral Black, 407.
  "     Blue, 207.
  "     Brown, 342.
  "     colours, darkening of, 284.
  "     Gray, 375.
  "     Green, 288.
  "     Green, German, 288.
  "     Kermes, 159.
  "     Orange, 258.
  "     Pitch, 337.
  "     Purple, 290.
  "     Turbith, 123.
  "     Yellow, 106, 116, 121.

Minérale, Jaune, 94.
  "       Laque, 258.

Miniature painter, a, 401.

Minium, 151, 153.

Mitis Green, 271.

Mixed Colours:--
  "   Black, 402.
  "   Brown, 346.
  "   Citrine, 314.
  "   Gray, 377.
  "   Green, 277.
  "   Grey, 384.
  "   Marrone, 367.
  "   Olive, 328.
  "   Orange, 249.
  "   Purple, 290.
  "   Russet, 322.

Mixed tints, on, 249-252, 262.

Mixture, a, 199.
  "      of Bitumen and Mummy,  348.
  "      of coloured rays, 384.
  "      of material colours, 384.
  "      unnecessary, 35.

Modan or Morat White, 80.

Modern pigments, 41-45.
  "    detractors of, 43-45.
  "    inferior, 41.
  "    superior, 42.

Molybdenum Green, 289.

Monicon, 257.

Montabert, De, 405.

Montbeillard, Roman pavement at,  218.

Montpellier Yellow, 121.

Mountain Blue, 228.
  "      Green, 274.

Mountains, 254.

Mummy, 347.
  "    Brown, 347.
  "    and Bitumen, mixed, 348.

Murexide, 169.

Musée Minéralogique, of Paris,  219.

Mutrie, Miss, 143.
  "     Yellow, 92.


N.

Naphthaline, 162.

Naples Yellow, modern, 104.
  "    old, 103.

Napoleon, Emperor, 176.

Native Bitumen, 338.
  "    Green, 267.
  "    Prussian Blue, 207, 226.
  "    Ultramarine, 216.

Natural Ultramarine, 216.

Nature, colour in, 311.
  "     gradation in, 326.
  "     palette of, 185.
  "     study of, 24.

Negative colours, 28.

Nepos Cornelius, 295.

Neutral colours, 27.
  "     Orange, Penley's, 253.
  "     Tint, 377.

Neutrality and colour, 375, 376.

Neutrals, colour as applied to the,  62.

New Blue, 216.
  "       pigments, 41-45.

Nickel Brown, 358.

Nineveh, 6, 218.

Nottingham White, 73.


O.

Objectionable pigments, substitutes for, 96, 104, 114.

Ochre, Black, 404
  "    Blue, 226.
  "    Brown, 108.
  "    Browns, 358.
  "    Burnt Roman, 255.
  "    Chrome, 267.
  "    Green, 287.
  "    Indian, 148.
  "    Orange, 255.
  "    Oxford, 109.
  "    Purple, 290.
  "    Red, 147.
  "    Roman, 107.
  "    Scarlet, 149.
  "    Spanish, 255.
  "    Spruce, 108.
  "    Stone, 109.
  "    Transparent Gold, 108.
  "    Yellow, 106.

Ochres and foul air, 359.
  "    Red, 146-150.
  "    Yellow, 105-109.

Ocre de Ru, 108

Oil, coal-tar colours in, 247.
  "  water-colour cakes in, 50.

Oils, 33, 152, 194.

Olive, 28.
  "    analysis of, 330.
  "    as a colour, 325.
  "    contrast of, 325.
  "    on the Tertiary, 325.

OLIVE PIGMENTS:--
  Burnt Verdigris, 331.
  Dewint's Green, 330.
  Mixed Olive, 328.
  Olive Green, 330.
  Olive Lake, 331.
  Olive Oxide of Chromium, 331.
  Olive Rinman's Green, 332.
  Olive Scheele's Green, 332.
  Olive Schweinfurt Green, 332.
  Olive Terre Verte, 333.

Olive purples, 301.

Olympian Green, 271.

O'Neill, Mr., 159.

Opacity of pigments, 48.

Orange, 28,
  "     as a colour, 239.
  "     as an archeus, 240.
  "     contrast of, 240.
  "     discordant, 240.
  "     on the Secondary, 239.

ORANGE PIGMENTS:--
  Anotta, 255.
  Antimony Orange, 256.
  Bixine, 256.
  Burnt Roman Ochre, 255.
  Burnt Sienna, 243.
  Burnt Terra di Sienna, 243.
  Cadmium Orange, 36, 244.
  Chinese Orange, 246.
  Chromate of Mercury, 256.
  Chrome Orange, 248.
  Damonico, 257.
  Gamboge Orange, 257.
  Golden Sulphur of Antimony, 256.
  Golden Yellow, 256.
  Laque Minérale, 258.
  Madder Orange, 258, 353.
  Mars Orange, 248.
  Mineral Orange, 248.
  Mixed Orange, 249.
  Monicon, 257.
  Neutral Orange, 253.
  Orange Chrome, 248.
  Orange Chromate of Lead, 248.
  Orange de Mars, 248.
  Orange Lake, 258.
  Orange Lead, 258.
  Orange Ochre, 255.
  Orange Orpiment, 258.
  Penley's Neutral Orange, 253.
  Realgar, 258.
  Red Orpiment, 258.
  Rocou, 255.
  Spanish Ochre, 255.
  Terra Orellana, 255.
  Thallium Orange, 259.
  Uranium Orange, 260.
  Zinc Orange, 261.

Orange Russet, 321.
  "    Vermilion, 157.
  "      "        Field's, 158.

Order of Colours:--
  White, 62-80, 414.
  Yellow, 81-126.
  Red, 127-182.
  Blue, 183-238.
  Orange, 239-262.
  Green, 263-293.
  Purple, 294-309.
  Citrine, 310-319.
  Russet, 320-324.
  Olive, 325-333.
  Brown, 334-361.
  Marrone, 362-371.
  Gray, 372-380.
  Grey, 381-386.
  Black, 387-413.

Organic pigments with lead chromates, 248.

Orient Yellow, 42, 110.

Original pigments, 35.
  "      importance of, 240-242.

Orpiment Yellow, 111-113.

Outremer, 217.

Outremer de Guimet, 209.

Oxford Ochre, 109.

Oxidation of pigments, 38.

Oxide, Chrome, 267.
  "    of Chromium, Green, 267.
  "     " Opaque, 267.
  "     " Transparent, 268.

Oxychloride of Lead, 73.

Oxygenated water, 69.

Oyster-shell, white of, 80.


P.

Paille de Mil, 170.

Painting, siliceous, 212.

Pale Cadmium, 90.
  "  Chrome, 93.
  "  Vermilion, 154.
  "  washes of a pigment, 91.

Palette, disinfectants of the, 359.
  "      motto for the, 156.
  "      setting the, 23.

Palette-knife, avoidance of a steel, 39, 50, 90, 103.

Palladium, 122.

Paper Black, 407.
  "   Smalt and Ultramarine in, 196.
  "   to give a tone to, 253.

Paris Blue, 192, 203.

Paris, Musée Minéralogique at, 219.
  "    Société d'Encouragement of, 210.

Particular colour, predilection for a, 58, 59.

Patent Green, 271.
  "    Yellow, 121.

Pattison's White, 73.

Paul Veronese, 229, 335.

Payne's Gray, 378.

Peach Black, 407.

Pearl White, 78.

Peganum Harmala, 171.

Penley, Mr. Aaron, 85-87, 158, 268, 270.

Penley's Neutral Orange, 253.

Perfect pigment, a, 46.

Perkin, Mr. W., 162.

Permanent Blue, 216.
  "       pigments, 252, 278, 300, 315, 323, 329.
  "       White, 65.

Peroxidized pigments, 38.

Persian berries, 312.
  "     Green, 271.
  "     lazur, 228.
  "     Red, 148.

Perspective, aerial, 22, 23.
  "          linear, 22.
  "          of colours, 22, 23.

Persulphomolybdates, 171.

Philocles, 7.

Phosphine, 162.

Photography, lamp black in, 401.
  "          pigments generally in, 401.

Pickle Green, 276.

Picric acid, 162.

Picture galleries, 363-365.

Pictures and pigments, 292.

Pigment and colour, 31.

Pigments, action of fire and time on 31.
  "       adulteration of, 70.
  "       apt to vary, 126, 181.
  "       beauty in, 46.
  "       blending of, 37.
  "       common, 359.
  "       compound, 36.
  "       drying of, 50.
  "       fineness of texture in, 50.
  "       grinding of, 37.
  "       individual beauty of, 58.
  "       innoxious, 53.
  "       on the Durability and Fugacity of, 31.
  "       on the General Qualities of, 46.
  "       opacity and transparency of, 48.
  "       past and present, 293.
  "       rays from, 384.
  "       truth of hue in, 47.
  "       vehicles with, 48-53.
  "       working well, 49.

Pink, Brown, 313.
  "   Dutch, 100.
  "   English, 100.
  "   Italian, 100.
  "   Madder, 144.
  "   Rose, 173.
  "   Saucers, 174.

Pitch, Jew's, 337.
  "    Mineral, 337.

Pittacal, 234.

Platinum Blue, 233.
  "      Yellow, 121.

Playfair, Dr. Lyon, 355.

Pliny, 7, 153, 198, 218, 295, 338.

Plumbago, 393.

Polygnotus, 9.

Pompeii, 105, 229.

Porcelain, blue for, 235.
  "        green for, 267.

Poussin, 11, 316.

Powder Blue, 196.

Power of pigments, individual, 59.

Powers of colours, 82.

Practice of Sir J. Reynolds, 37.

Precipitate, Red, 173.

Prevention and cure, 412.

Price, Dr. D. S., 69.

Primary colours, 28.

Principles of practice, 35.

Process, Autotype, 401.

Protoxide, pigments in the state of, 37.

Proust, M., 396.

Prout, Samuel, 346.

Prout's Brown, Liquid, 345.

Prussian Black, 404, 408.
  "      Copper, 408.

Prussian Blue, 203.
  "      adulteration of, 203.
  "      character of, 237, 278, 301.
  "      Cobalt, 227.
  "      manufacture of, 203.
  "      Native, 207, 226.
  "      want of a permanent, 189.
  "      with alkalies, 206.

Prussian Brown, 348.
  "        "    French, 255.
  "      Greens, 281, 282.
  "      Red, 149.

Prussiate of Copper, 323.
  "       Iron, 203.

Pure Scarlet, 150.
  "  Ultramarine, 216.

Purple, 28.
  "     as a colour, 295.
  "     as a pigment, 297.
  "     Black, 369, 408.
  "     Brown, 359.
  "     contrast of, 294, 297.
  "     Lake, 137.
  "     on the Secondary, 294.

PURPLE PIGMENTS:--
  Archil Purple, 303.
  Bismuth Purple, 304.
  Burnt Carmine, 298.
  Burnt Lake, 298.
  Burnt Madder, 305.
  Cassius's Purple Precipitate, 306.
  Cobalt Purples, 305.
  Field's Purple, 301.
  Gold Purple, 306.
  Indian Purple, 298.
  Mars Violet, 290.
  Mauve, 163.
  Mineral Purple, 290.
  Mixed Purple, 290.
  Prussian Purple, 307.
  Purple Madder, 301.
  Purple Ochre, 290.
  Purple of Cassius, 306.
  Purple Rubiate, 301.
  Sandal Wood Purple, 307.
  Solid French Purple, 304.
  Tin Violet, 308.
  Violet Carmine, 302.
  Violet de Mars, 290.
  Purple, pure, 300.
    "     Tyrian, 295, 296.

Purpurates, 170.

Purree, 98.


Q.

Qualities of Pigments, on the General, 46.

Queen's Yellow, 123.

Quercitron Lake, 100, 312.
  "        Yellow, 100.

Quinine Green, 289.


R.

Ramnus infectorius, 315.

Raphael, 8, 9.

Rare Metals, 172.

Raw Sienna, 113.
  " Umber, 315.

Rays from pigments, 384.

Real Ultramarine, 216.

Realgar, 258.

Reboulleau's Blue, 230.

Red, 28.
  "  as a colour, 128.
  "  contrasts of, 128, 129.
  "  discordant, 129.
  "  Marrone, 368.
  "  on the Primary, 127.
  "  Orpiment, 258.

RED PIGMENTS:--
  Almagra, 147.
  Antimony Red, 159.
  Armenian Bole, 147.
  Bloodstone, 147.
  Brown Red, 147.
  Cadmium Red, 130.
  Carmine, 133-135.
  Carmine Vermilion, 156.
  Carnagione, 149.
  Chica Red, 159.
  Chinese Lake, 137.
  Chinese Rouge, 174.
  Chinese Vermilion, 156.
  Coal-Tar Colours, 160.
  Cobalt Reds, 164.
  Cochineal Lakes, 131-137.
  Copper Reds, 164.
  Crimson Lake, 135.
  Deep Vermilion, 154.
  Dragon's Blood, 137.
  English Red, 149.
  English Vermilion, 146.
  Extract of Vermilion, 157.
  Ferrate of Baryta, 165.
  Field's Carmine, 142.
  Field's Lakes, 139-145.
  Field's Orange Vermilion, 158.
  Florentine Lake, 137.

RED PIGMENTS:--
  Gold Reds, 166.
  Hamburgh Lake, 137.
  Indian Lake, 138.
  Indian Ochre, 146.
  Indian Red, 148.
  Iodine Pink, 166.
  Iodine Scarlet, 150.
  Kermes Lake, 167.
  Lac Lake, 138.
  Lawson's Red, 168.
  Light Red, 149.
  Liquid Madder Lake, 145.
  Liquid Rubiate, 145.
  Madder Carmine, 142.
  Madder Lake, 144.
  Madder Lakes, 139-145.
  Magenta, 160.
  Majolica, 146.
  Manganese Red, 168.
  Mars Red, 145.
  Mineral Kermes, 159.
  Minium, 151.
  Murexide, 169.
  Ochres, 146-150.
  Orange Vermilion, 157.
  Paille de Mil, 170.
  Pale Vermilion, 154.
  Peganum Harmala, 171.
  Persian Red, 148.
  Persulphomolybdates, 171.
  Pink Madder, 144.
  Pink Saucers, 174.
  Prussian Red, 149.
  Pure Scarlet, 150.
  Purple Lake, 137.
  Red Chalk, 172.
  Red Chrome, 151.
  Red Lead, 151.
  Red Ochre, 147.
  Red Precipitate, 173.
  Redding, 146.
  Roman Lake, 137.
  Rose Madder, 143.
  Rose Pink, 173.
  Rose Rubiate, 145.
  Rouge, 173.
  Rouge de Mars, 145.
  Rubric Lakes, 139-145.
  Rufigallic Red, 174.
  Sandal Red, 175.
  Saturnine Red, 151.
  Scarlet Chrome, 151.
  Scarlet Lake, 136.
  Scarlet Ochre, 149.
  Scarlet Vermilion, 156.
  Sil Atticum, 147.
  Silver Red, 176.
  Sinoper, 151.
  Sorgho Red, 176.
  Spanish Brown, 146.
  Spanish Red, 150.
  Terra Puzzoli, 149.
  Terra Sinopica, 147.
  Thallium Red, 177.
  Tin Pink, 177.
  Ultramarine Red, 178.
  Uranium Red, 179.
  Venetian Lake, 137.
  Venetian Red, 149.
  Vermilion, 154.
  Vermilions, 153-158.
  Wongshy Red, 180.

Reds, ancient, 5.

Relations of colour, 13-24.

Relative durability of colour, 32.

Rembrandt, 11, 345.

Revelation, Book of, 217.

Reynolds, Sir Joshua, 10, 35, 37, 158, 374, 410.

Rinman's Green, 285.
  "      Olive, 332.

Rocou, 255.

Roman Green, 290.
  "   Lake, 137.
  "   Ochre, 107.
  "     "    Burnt, 255.
  "   painters and painting, 7, 8, 10, 391.
  "   Sepia, 351.
  "   White, 74.

Romans, the, 153, 295.

Romulus, 295.

Rosaniline, 162.

Rose, the, 327.

Rousseau, M. E., 414.

Rowbotham, Messrs., 144.

Royal Academy at Burlington House, 365.
  "   Blue, 196.

Rubens, 11, 37, 64, 157, 283, 334, 374.
  "     Brown, 359.
  "     Madder, 321.

Rubia tinctorum, 139.

Rubiate, Purple, 301.

Rue, Dr. Warren de la, 132.

Ruskin, Mr., 13.

Russet, 28.
  "     analysis of, 330.
  "     as a colour, 320.
  "     contrast of, 321.
  "     on the Tertiary, 320.

RUSSET PIGMENTS:--
  Field's Russet, 321.
  Mixed Russet, 322.
  Orange Russet, 321.
  Prussiate of Copper, 323.
  Rubens' Madder, 321.
  Russet Rubiate, 321.


S.

Sacc, M., 414.

Safflower, 174.

Samuel Prout, 346.

Sandal Red, 175.
  "    Wood Purple, 307.

Sandarac, 259.

Sap Green, 282.

Satin White, 80.

Saturnine Red, 151.

Saucers, Pink, 174.

Saunders Blue, 230.

Saxon Blue, 189.
  "   Green, 271.
  "   Smalts, 215.

Scarlet Chrome, 151.
  "     Iodine, 150.
  "     Lake, 136.
  "     Ochre, 149.
  "     Pure, 150.
  "     transparent, a, reward for, 130.
  "       "          substitute for, 130.
  "     Vermilion, 156.

Scheele's Green, 272.
  "       Olive, 332.

Schools of painting, 8-10, 37.

Schunck, Dr., 140.

Schweinfurt Blue, 230.
  "         Green, 271.
  "           "   Olive, 332.

Scoffern, Dr., 357.

Sea, the Dead, 337.
  "  transparency of the, 269.

Secondary colours, 28.
  "       pigments, 242.

Semi-Neutral colours, 29.
  "  the term, 334.

Semi-stability, on, 308.

Semi-stable pigments, 298, 313.

Sepia, 348, 397.
  "    Liquid, 348.
  "    Roman, 350.
  "    Warm, 351.

Shades, 21.

Shadow, colour of, 27, 30.

Siccatives, 51-53.

Sienna, Burnt, 243.
  "     Raw, 113.
  "     Terra di, 113.

Sil Atticum, 147.

Silicate of Baryta, 290.

Siliceous painting, Ultramarine in, 212.

Silver Red, 176.
  "    White, 71.

Sinoper, 151.

Slate Clays, 380.
  "   powdered, 380.

Smalt, 195-198.
  "    adulteration of, 198.
  "    Copper, 229.

Smalt, grinding of, 197.
  "    in mural decoration, 198.
  "    in paper, 196.
  "    Iron, 218.

Soap and alkali in brushes, 52.

Société d'Encouragement of Paris, 210.

Society of Arts, 130.

Soda flame, 191.

Solid French Purple, 304.

Sorgho Red, 176.

Sources of pigments, 60.

South America, chica from, 368.

Spanish Black, 409.
  "     Brown, 146.
  "     Ochre, 255.
  "     Red, 150.
  "     Schools, 8.
  "     White, 80.

Spence, Mr., 68.

Spruce Ochre, 108.

St. Petersburg, palace at, 219.

Starch, 66.

Stil de Grain, Brown, 312.

Stippling, 315.

Stone, Armenian, 228.
  "    lapis lazuli, 217, 219.
  "    malachite, 274.
  "    Ochre, 109.

Strontian Yellow, 113.

Sulphate of Lead, 72.
  "      zinc, 51.

Sulphide of cadmium, thallium in, 260.

Sulphur and ochres, 359.

Sulphuretted hydrogen, pigments affected by, 39, 67, 69, 73, 78, 79, 93, 103, 120, 151, 152, 229, 248, 275, 276.

Susa, 296.

Swedish Green, 272.

Synonyms, value of, 145.


T.

Talent of money, 296.

Teniers, 360.

Terra di Sienna, 113.
  "    "   "     Burnt, 243.
  "   Orellana, 255.
  "   Puzzoli, 149.
  "   Sinopica, 147.

Terre Bleu, 228.
  "   Verte, 283.
  "     "    Olive, 333.

Terrene whites, 66, 80.

Tertiary colours, 28.
  "      on, 311.

Thallium, in sulphide of cadmium, 260.
  "       Orange, 259.
  "       Red, 177.
  "       Yellow, 122.

Thebes, mausoleum at, 3.

Thénard, M., 69, 192.

Thénard's Blue, 192.

Theophrastus, 198.

Theory and practice, 410.

Thwaites' Yellow, 122.

Time, pigments affected by, 40.

Tin Pink, 177.
  "       Violet, 308.
  "       White, 79.

Tin-Copper Green, 286.

Tint, Harding's, 380.
  "   Macpherson's, 380.
  "   Neutral, 377.

Tintoret, 8.

Tints, 27.

Titanium Green, 290.

Titian, 7, 8, 9, 11, 37, 150, 157, 293, 334.

Transparency of pigments, 48.
  "   to obtain, 245.

Transparent Gold Ochre, 108.
  "         Oxide of Chromium, 268.
  "         pigments, use of, 237.

Troy White, 80.

True Chrome Green, 267.
  "  Prussian Green, 281.
  "  Ultramarine, 216.

Truth of hue in pigments, 47.

Tullus Hostilius, 295.

Tungsten Blue, 233.
  "      White, 414.

Turacine, 165.

Turbith Mineral, 123.

Turkey Berries, 312.

Turnbull's Blue, 208.

Turner, 309, 328.

Turner's Yellow, 121.

Tyrian Purple, 295, 296.


U.

Ultramarine, Artificial, 209-216.
  "          acid pigments with, 214.
  "          adulteration of, 215.
  "          experiment with, 213.
  "          green in, 211.
  "          gum with, 214.
  "          in siliceous painting, 212.
  "          test for, 212.

Ultramarine Ash, 379.
  "         Beggars', 409.
  "         Brilliant, 215.
  "         Cobalt, 192.
  "         Dutch, 189.
  "         Factitious, 215.
  "         French, 215.

Ultramarine, Genuine, 216-225.
  "          adulteration of, 224.
  "          colouring matter of, 224.
  "          defects in, 222, 223.
  "          manufacture of, 220.
  "          price of, 220.
  "          properties of, 221.
  "          tests for, 224.

Ultramarine, Gmelin's German, 209.
  "          Green, 287.
  "          Guimet's, 209-211.
  "          Native, 216.
  "          Natural, 216.
  "          Pure, 217.
  "          Real, 216.
  "          Red, 178.
  "          True, 216.

Umber, 315.
  "    Burnt, 341.
  "    grounds primed with, 316.
  "    Raw, 315.

Unnecessary mixture, 35.

Uranium Brown, 360,
  "     Green, 291.
  "     Orange, 260.
  "     Red, 179.
  "     Yellow, 123.

Ure, Dr., 73.


V.

Vanadium Green, 291.

Vandyke, 11, 150, 220, 351.
  "      Brown, 351.

Van Eyck, 167.

Varnishes, 33, 152.

Vegetal charcoal, 398.

Vehicles with pigments, 48-53.

Velasquez, 389.

Venetian Green, 283.
  "      Lake, 137.
  "      painters, painting, and pigments, 7, 8, 34, 37, 139, 167.
  "      Red, 149.
  "      White, 75.

Verde Vessie, 282.

Verdetto, 283.

Verdigris, 51, 276.
  "        Burnt, 331.
  "        Distilled, 276.

Verditer, Blue, 228.
  "       Green, 287.

Vermilion, 153-158.
  "        adulteration of, 156.
  "        Carmine, 156.
  "        Chinese, and English, 156, 146.
  "        Deep, 154.
  "        European and Chinese, 154.
  "        Extract of, 157.
  "        Field's Orange, 158.
  "        manufacture of, 154.
  "        Orange, 157.

Vermilion Pale, 154.
  "       Scarlet, 156.
  "       with cochineal lake, 136.
  "       with iodide of mercury, 155.

Verona Brown, 353.
  "    Green, 283.

Veronese Green, 268.
  "      French, 268.

Vert de Zinc, 285.

Vicious extremes in colouring, 59.

Vienna Blue, 192.
  "    Green, 271.
  "    White, 72.

Vine Black, 394.

Violet, Carmine, 302.
  "     de Mars, 290.
  "     Mars, 290.
  "     Tin, 308.

Viride Æris, 276.

Viridian, 42, 269.

Vision, derangement of, 59.

Vitrification and permanence, 197.

Vitrified colours, 33, 103, 197.

Vitruvius, 229.


W.

Wall colour for picture galleries, 363.
  "  space in     "       "        364.

Walpole, Mrs., 220.

Warm Sepia, 350.

Water-colour cakes in oil, 50.

Watts, Mr., 165.

Weppen, 398.

White, 27.
  "    as a colour, 62.
  "    as a pigment, 64.
  "    Chalk, 79.
  "    colour as applied to, 62.

Whitelac varnish, 50.

White Lead, 67-70.
  "   adulteration of, 70.
  "   colour restored in, 69.
  "   hydrated oxide in, 68.
  "   loss of opacity in, 68.
  "   use of, 70.
  "   with Blue Black, 395.
  "     "  Bone Brown, 341.
  "     "  Brown Pink, 312.
  "     "  Cadmium Yellow, 89.
  "     "  Carmine, 134.
  "     "  Dragon's Blood, 138.
  "     "  Gamboge, 97.
  "     "  Indian Lake, 139.
  "     "  Indigo, 201.
  "     "  Massicot, 120.
  "     "  Orpiment, 112.
  "     "  Prussian Blue, 206.
  "     "  Red Lead, 152.
  "     " Yellow Lakes, 99.

White, on the Neutral, 62.
  "    perfect, 62, 64.

WHITE PIGMENTS:--
  Antimony White, 79.
  Arsenic White, 79.
  Barytic White, 65.
  Blanc d'Argent, 71.
  Body White, 72.
  Cadmium White, 78.
  Ceruse, 74.
  China White, 80.
  Chinese White, 75.
  Constant White, 65.
  Cremnitz or Kremnitz White, 72.
  Crems or Krems White, 72.
  Dutch White, 74.
  Flake White, 72.
  Flemish White, 72.
  French White, 71.
  Hamburgh White, 74.
  Kremser White, 75.
  London White, 73.
  Mercury White, 79.
  Modan or Morat White, 80.
  Nottingham White, 73.
  Oxychloride of Lead, 73.
  Pattison's White, 73.
  Pearl White, 78.
  Permanent White, 65.
  Roman White, 74.
  Rouen White, 80.
  Satin White, 80.
  Silver White, 71.
  Spanish White, 80.
  Sulphate of Lead, 72.
  Tin White, 79.
  Tungsten White, 414.
  Troy White, 80.
  Venetian White, 75.
  Vienna White, 72.
  White Lead, 67-70.
  Zinc White, 76.
  Zinc Whites, 75-78.

White, properties of, 62-64.
  "    use of, 64.

Whites, classified, 80.
  "     in old pictures, 65.

Williamson, Professor, 205.

Wilson, 336.

Winter scene, a water-colour, 352.

Wongshy Red, 180.

Wood-Tar Blue, 233.

Working well in pigments, 49.


Y.

Yellow, 28.
  "     as a colour, 82.
  "     contrasts of, 82, 83.

Yellow, discordant, 83.
  "     Golden, 256.
  "     Madder, Cory's, 353.
  "     on the Primary, 81.

YELLOW PIGMENTS:--
  Antimony Yellow, 105.
  Arsenic Yellow, 116.
  Aureolin, 83-87.
  Bismuth Yellow, 116.
  Brown Ochre, 108.
  Cadmium Yellows, 87-92.
  Cassel Yellow, 121.
  Chinese Yellow, 111.
  Chrome Yellows, 93-95.
  Citron Yellow, 95.
  Cologne Yellow, 94.
  Copper Yellow, 116.
  Deep Cadmium, 87.
  Deep Chrome, 93.
  Di Palito, 109.
  Drop Gum, 96.
  Dutch Pink, 100.
  English Pink, 100.
  Extract of Gamboge, 97.
  Gallstone, 95.
  Gamboge, 96.
  Gelbin's Yellow, 117.
  Giallolino, 103.
  Indian Yellow, 98.
  Indium Yellow, 117.
  Iodine Yellow, 118.
  Iron Yellow, 102, 118.
  Italian Pink, 100.
  Jaune de Cologne, 94.
  Jaune de Fer, 102.
  Jaune de Mars, 102.
  Jaune Minérale, 94.
  King's Yellow, 111.
  Lakes, 99, 100.
  Lemon Cadmium, 91.
  Lemon Yellow, 101.
  Litharge, 120.
  Madder Yellow, 118, 353.
  Mars Yellow, 102.
  Massicot, 120.
  Mineral Yellow, 106, 116, 121.
  Montpellier Yellow, 121.
  Mutrie Yellow, 92.
  Naples Yellow, 103.
  Ochres, 105-109.
  Ocre de Ru, 108.
  Orient Yellow, 110.
  Orpiment or Yellow Orpiment, 111.
  Oxford Ochre, 109.
  Pale Cadmium, 90.
  Pale Chrome, 93.
  Patent Yellow, 121.
  Platinum Yellow, 121.
  Purree, 98.
  Queen's Yellow, 123.
  Quercitron Lake, or Yellow, 100.
  Raw Sienna, 113.
  Roman Ochre, 107.
  Spruce Ochre, 108.
  Stone Ochre, 109.
  Strontian Yellow, 113.
  Terra di Sienna, 113.
  Thallium Yellow, 122.
  Thwaites' Yellow, 122.
  Transparent Gold Ochre, 108.
  Turbith Yellow, 123.
  Turner's Yellow, 121.
  Uranium Yellow, 123.
  Yellow Carmine, 123.
  Yellow Lake, 100.
  Yellow Ochre, 106.

Yellows, ancient, 5.
  "      classified, 125.
  "      former paucity of, 83.
  "      various, 124.


Z.

Zaffre, 189.

Zeuxis and Apelles, 7.

Zinc Brown, 360.
  "  Cobalt Blue, 235.
  "  Green, 285.
  "  Orange, 261,
  "  siccatives, 51, 77.
  "  Vert de, 285.
  "  White, 76.
  "   "     adulteration of, 77.
  "   "     over White Lead, 76.
  "  Whites, 75-78.




ERRATA.


Page  16 _for_ inharmonious _read_ harmonious
  "   35 _for_ There prevails _read_ There prevail
  "   48 _for_ as whiteness, or light do, _read_ as whiteness or light does
  "  166 _for_ purple of cassius _read_ purple of Cassius
  "  182 _for_ which manufactures _read_ which manufactures pictures
  "  258 _for_ _Laque Minéral_ _read_ _Laque Minérale_
  "  342 _for_ rivals _read_ rivels
  "  378 _for_ predominate _read_ predominates


THE END.


LONDON:
Printed by A. Schulze, 13, Poland Street.


+------------------------------------------------------+
|Transcriber's Note:                                   |
|                                                      |
|The errata above and the following have been corrected|
|in the text:                                          |
|                                                      |
|Page  vi Semi-neutral changed to Semi-Neutral         |
|      10 life less changed to lifeless                |
|      17 sun-rise changed to sunrise                  |
|      20 in the the changed to in the                 |
|      22 perpective changed to perspective            |
|      29 marone changed to marrone                    |
|      69 di-carbonate changed to dicarbonate          |
|      73 hydrogren changed to hydrogen                |
|      77 imimical changed to inimical                 |
|      81 feuillemorte changed to feuillemort          |
|      91 Item numbering has been left consistent      |
|         with the omission of item no. 23             |
|     129 extemes changed to extremes                  |
|     169 muroxide changed to murexide                 |
|     188 dullness changed to dulness                  |
|     192 gaslight changed to gas-light                |
|     200 durablity changed to durability              |
|     206 and 293 developement changed to development  |
|     212 decolorized changed to decolourised          |
|     235 indentical changed to identical              |
|     241 re-acting changed to reacting                |
|     250 Exibition changed to Exhibition              |
|     273 childrens' changed to children's             |
|     336 toneing changed to toning                    |
|     352 fine tooth-comb changed to fine-tooth comb   |
|     408 analagous changed to analogous               |
|     414 announceed changed to announced              |
|     421 abies changed to Abies                       |
|                                                      |
|Inconsistencies in the use of analyse/analyze,        |
|harmonise/harmonize and neutralise/neutralize have    |
|been retained as in the original text, as have the    |
|use of aërial and aerial.                             |
+------------------------------------------------------+


*** END OF THE PROJECT GUTENBERG EBOOK FIELD'S CHROMATOGRAPHY ***

Updated editions will replace the previous one--the old editions will
be renamed.

Creating the works from print editions not protected by U.S. copyright
law means that no one owns a United States copyright in these works,
so the Foundation (and you!) can copy and distribute it in the
United States without permission and without paying copyright
royalties. Special rules, set forth in the General Terms of Use part
of this license, apply to copying and distributing Project
Gutenberg-tm electronic works to protect the PROJECT GUTENBERG-tm
concept and trademark. Project Gutenberg is a registered trademark,
and may not be used if you charge for an eBook, except by following
the terms of the trademark license, including paying royalties for use
of the Project Gutenberg trademark. If you do not charge anything for
copies of this eBook, complying with the trademark license is very
easy. You may use this eBook for nearly any purpose such as creation
of derivative works, reports, performances and research. Project
Gutenberg eBooks may be modified and printed and given away--you may
do practically ANYTHING in the United States with eBooks not protected
by U.S. copyright law. Redistribution is subject to the trademark
license, especially commercial redistribution.

START: FULL LICENSE

THE FULL PROJECT GUTENBERG LICENSE
PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK

To protect the Project Gutenberg-tm mission of promoting the free
distribution of electronic works, by using or distributing this work
(or any other work associated in any way with the phrase "Project
Gutenberg"), you agree to comply with all the terms of the Full
Project Gutenberg-tm License available with this file or online at
www.gutenberg.org/license.

Section 1. General Terms of Use and Redistributing Project
Gutenberg-tm electronic works

1.A. By reading or using any part of this Project Gutenberg-tm
electronic work, you indicate that you have read, understand, agree to
and accept all the terms of this license and intellectual property
(trademark/copyright) agreement. If you do not agree to abide by all
the terms of this agreement, you must cease using and return or
destroy all copies of Project Gutenberg-tm electronic works in your
possession. If you paid a fee for obtaining a copy of or access to a
Project Gutenberg-tm electronic work and you do not agree to be bound
by the terms of this agreement, you may obtain a refund from the
person or entity to whom you paid the fee as set forth in paragraph
1.E.8.

1.B. "Project Gutenberg" is a registered trademark. It may only be
used on or associated in any way with an electronic work by people who
agree to be bound by the terms of this agreement. There are a few
things that you can do with most Project Gutenberg-tm electronic works
even without complying with the full terms of this agreement. See
paragraph 1.C below. There are a lot of things you can do with Project
Gutenberg-tm electronic works if you follow the terms of this
agreement and help preserve free future access to Project Gutenberg-tm
electronic works. See paragraph 1.E below.

1.C. The Project Gutenberg Literary Archive Foundation ("the
Foundation" or PGLAF), owns a compilation copyright in the collection
of Project Gutenberg-tm electronic works. Nearly all the individual
works in the collection are in the public domain in the United
States. If an individual work is unprotected by copyright law in the
United States and you are located in the United States, we do not
claim a right to prevent you from copying, distributing, performing,
displaying or creating derivative works based on the work as long as
all references to Project Gutenberg are removed. Of course, we hope
that you will support the Project Gutenberg-tm mission of promoting
free access to electronic works by freely sharing Project Gutenberg-tm
works in compliance with the terms of this agreement for keeping the
Project Gutenberg-tm name associated with the work. You can easily
comply with the terms of this agreement by keeping this work in the
same format with its attached full Project Gutenberg-tm License when
you share it without charge with others.

1.D. The copyright laws of the place where you are located also govern
what you can do with this work. Copyright laws in most countries are
in a constant state of change. If you are outside the United States,
check the laws of your country in addition to the terms of this
agreement before downloading, copying, displaying, performing,
distributing or creating derivative works based on this work or any
other Project Gutenberg-tm work. The Foundation makes no
representations concerning the copyright status of any work in any
country other than the United States.

1.E. Unless you have removed all references to Project Gutenberg:

1.E.1. The following sentence, with active links to, or other
immediate access to, the full Project Gutenberg-tm License must appear
prominently whenever any copy of a Project Gutenberg-tm work (any work
on which the phrase "Project Gutenberg" appears, or with which the
phrase "Project Gutenberg" is associated) is accessed, displayed,
performed, viewed, copied or distributed:

  This eBook is for the use of anyone anywhere in the United States and
  most other parts of the world at no cost and with almost no
  restrictions whatsoever. You may copy it, give it away or re-use it
  under the terms of the Project Gutenberg License included with this
  eBook or online at www.gutenberg.org. If you are not located in the
  United States, you will have to check the laws of the country where
  you are located before using this eBook.

1.E.2. If an individual Project Gutenberg-tm electronic work is
derived from texts not protected by U.S. copyright law (does not
contain a notice indicating that it is posted with permission of the
copyright holder), the work can be copied and distributed to anyone in
the United States without paying any fees or charges. If you are
redistributing or providing access to a work with the phrase "Project
Gutenberg" associated with or appearing on the work, you must comply
either with the requirements of paragraphs 1.E.1 through 1.E.7 or
obtain permission for the use of the work and the Project Gutenberg-tm
trademark as set forth in paragraphs 1.E.8 or 1.E.9.

1.E.3. If an individual Project Gutenberg-tm electronic work is posted
with the permission of the copyright holder, your use and distribution
must comply with both paragraphs 1.E.1 through 1.E.7 and any
additional terms imposed by the copyright holder. Additional terms
will be linked to the Project Gutenberg-tm License for all works
posted with the permission of the copyright holder found at the
beginning of this work.

1.E.4. Do not unlink or detach or remove the full Project Gutenberg-tm
License terms from this work, or any files containing a part of this
work or any other work associated with Project Gutenberg-tm.

1.E.5. Do not copy, display, perform, distribute or redistribute this
electronic work, or any part of this electronic work, without
prominently displaying the sentence set forth in paragraph 1.E.1 with
active links or immediate access to the full terms of the Project
Gutenberg-tm License.

1.E.6. You may convert to and distribute this work in any binary,
compressed, marked up, nonproprietary or proprietary form, including
any word processing or hypertext form. However, if you provide access
to or distribute copies of a Project Gutenberg-tm work in a format
other than "Plain Vanilla ASCII" or other format used in the official
version posted on the official Project Gutenberg-tm website
(www.gutenberg.org), you must, at no additional cost, fee or expense
to the user, provide a copy, a means of exporting a copy, or a means
of obtaining a copy upon request, of the work in its original "Plain
Vanilla ASCII" or other form. Any alternate format must include the
full Project Gutenberg-tm License as specified in paragraph 1.E.1.

1.E.7. Do not charge a fee for access to, viewing, displaying,
performing, copying or distributing any Project Gutenberg-tm works
unless you comply with paragraph 1.E.8 or 1.E.9.

1.E.8. You may charge a reasonable fee for copies of or providing
access to or distributing Project Gutenberg-tm electronic works
provided that:

* You pay a royalty fee of 20% of the gross profits you derive from
  the use of Project Gutenberg-tm works calculated using the method
  you already use to calculate your applicable taxes. The fee is owed
  to the owner of the Project Gutenberg-tm trademark, but he has
  agreed to donate royalties under this paragraph to the Project
  Gutenberg Literary Archive Foundation. Royalty payments must be paid
  within 60 days following each date on which you prepare (or are
  legally required to prepare) your periodic tax returns. Royalty
  payments should be clearly marked as such and sent to the Project
  Gutenberg Literary Archive Foundation at the address specified in
  Section 4, "Information about donations to the Project Gutenberg
  Literary Archive Foundation."

* You provide a full refund of any money paid by a user who notifies
  you in writing (or by e-mail) within 30 days of receipt that s/he
  does not agree to the terms of the full Project Gutenberg-tm
  License. You must require such a user to return or destroy all
  copies of the works possessed in a physical medium and discontinue
  all use of and all access to other copies of Project Gutenberg-tm
  works.

* You provide, in accordance with paragraph 1.F.3, a full refund of
  any money paid for a work or a replacement copy, if a defect in the
  electronic work is discovered and reported to you within 90 days of
  receipt of the work.

* You comply with all other terms of this agreement for free
  distribution of Project Gutenberg-tm works.

1.E.9. If you wish to charge a fee or distribute a Project
Gutenberg-tm electronic work or group of works on different terms than
are set forth in this agreement, you must obtain permission in writing
from the Project Gutenberg Literary Archive Foundation, the manager of
the Project Gutenberg-tm trademark. Contact the Foundation as set
forth in Section 3 below.

1.F.

1.F.1. Project Gutenberg volunteers and employees expend considerable
effort to identify, do copyright research on, transcribe and proofread
works not protected by U.S. copyright law in creating the Project
Gutenberg-tm collection. Despite these efforts, Project Gutenberg-tm
electronic works, and the medium on which they may be stored, may
contain "Defects," such as, but not limited to, incomplete, inaccurate
or corrupt data, transcription errors, a copyright or other
intellectual property infringement, a defective or damaged disk or
other medium, a computer virus, or computer codes that damage or
cannot be read by your equipment.

1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the "Right
of Replacement or Refund" described in paragraph 1.F.3, the Project
Gutenberg Literary Archive Foundation, the owner of the Project
Gutenberg-tm trademark, and any other party distributing a Project
Gutenberg-tm electronic work under this agreement, disclaim all
liability to you for damages, costs and expenses, including legal
fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT
LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE
PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE
TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE
LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR
INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH
DAMAGE.

1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a
defect in this electronic work within 90 days of receiving it, you can
receive a refund of the money (if any) you paid for it by sending a
written explanation to the person you received the work from. If you
received the work on a physical medium, you must return the medium
with your written explanation. The person or entity that provided you
with the defective work may elect to provide a replacement copy in
lieu of a refund. If you received the work electronically, the person
or entity providing it to you may choose to give you a second
opportunity to receive the work electronically in lieu of a refund. If
the second copy is also defective, you may demand a refund in writing
without further opportunities to fix the problem.

1.F.4. Except for the limited right of replacement or refund set forth
in paragraph 1.F.3, this work is provided to you 'AS-IS', WITH NO
OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE.

1.F.5. Some states do not allow disclaimers of certain implied
warranties or the exclusion or limitation of certain types of
damages. If any disclaimer or limitation set forth in this agreement
violates the law of the state applicable to this agreement, the
agreement shall be interpreted to make the maximum disclaimer or
limitation permitted by the applicable state law. The invalidity or
unenforceability of any provision of this agreement shall not void the
remaining provisions.

1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the
trademark owner, any agent or employee of the Foundation, anyone
providing copies of Project Gutenberg-tm electronic works in
accordance with this agreement, and any volunteers associated with the
production, promotion and distribution of Project Gutenberg-tm
electronic works, harmless from all liability, costs and expenses,
including legal fees, that arise directly or indirectly from any of
the following which you do or cause to occur: (a) distribution of this
or any Project Gutenberg-tm work, (b) alteration, modification, or
additions or deletions to any Project Gutenberg-tm work, and (c) any
Defect you cause.

Section 2. Information about the Mission of Project Gutenberg-tm

Project Gutenberg-tm is synonymous with the free distribution of
electronic works in formats readable by the widest variety of
computers including obsolete, old, middle-aged and new computers. It
exists because of the efforts of hundreds of volunteers and donations
from people in all walks of life.

Volunteers and financial support to provide volunteers with the
assistance they need are critical to reaching Project Gutenberg-tm's
goals and ensuring that the Project Gutenberg-tm collection will
remain freely available for generations to come. In 2001, the Project
Gutenberg Literary Archive Foundation was created to provide a secure
and permanent future for Project Gutenberg-tm and future
generations. To learn more about the Project Gutenberg Literary
Archive Foundation and how your efforts and donations can help, see
Sections 3 and 4 and the Foundation information page at
www.gutenberg.org

Section 3. Information about the Project Gutenberg Literary
Archive Foundation

The Project Gutenberg Literary Archive Foundation is a non-profit
501(c)(3) educational corporation organized under the laws of the
state of Mississippi and granted tax exempt status by the Internal
Revenue Service. The Foundation's EIN or federal tax identification
number is 64-6221541. Contributions to the Project Gutenberg Literary
Archive Foundation are tax deductible to the full extent permitted by
U.S. federal laws and your state's laws.

The Foundation's business office is located at 809 North 1500 West,
Salt Lake City, UT 84116, (801) 596-1887. Email contact links and up
to date contact information can be found at the Foundation's website
and official page at www.gutenberg.org/contact

Section 4. Information about Donations to the Project Gutenberg
Literary Archive Foundation

Project Gutenberg-tm depends upon and cannot survive without
widespread public support and donations to carry out its mission of
increasing the number of public domain and licensed works that can be
freely distributed in machine-readable form accessible by the widest
array of equipment including outdated equipment. Many small donations
($1 to $5,000) are particularly important to maintaining tax exempt
status with the IRS.

The Foundation is committed to complying with the laws regulating
charities and charitable donations in all 50 states of the United
States. Compliance requirements are not uniform and it takes a
considerable effort, much paperwork and many fees to meet and keep up
with these requirements. We do not solicit donations in locations
where we have not received written confirmation of compliance. To SEND
DONATIONS or determine the status of compliance for any particular
state visit www.gutenberg.org/donate

While we cannot and do not solicit contributions from states where we
have not met the solicitation requirements, we know of no prohibition
against accepting unsolicited donations from donors in such states who
approach us with offers to donate.

International donations are gratefully accepted, but we cannot make
any statements concerning tax treatment of donations received from
outside the United States. U.S. laws alone swamp our small staff.

Please check the Project Gutenberg web pages for current donation
methods and addresses. Donations are accepted in a number of other
ways including checks, online payments and credit card donations. To
donate, please visit: www.gutenberg.org/donate

Section 5. General Information About Project Gutenberg-tm electronic works

Professor Michael S. Hart was the originator of the Project
Gutenberg-tm concept of a library of electronic works that could be
freely shared with anyone. For forty years, he produced and
distributed Project Gutenberg-tm eBooks with only a loose network of
volunteer support.

Project Gutenberg-tm eBooks are often created from several printed
editions, all of which are confirmed as not protected by copyright in
the U.S. unless a copyright notice is included. Thus, we do not
necessarily keep eBooks in compliance with any particular paper
edition.

Most people start at our website which has the main PG search
facility: www.gutenberg.org

This website includes information about Project Gutenberg-tm,
including how to make donations to the Project Gutenberg Literary
Archive Foundation, how to help produce our new eBooks, and how to
subscribe to our email newsletter to hear about new eBooks.