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.