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_.