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.