Gold Reds
: ON THE PRIMARY, RED.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.
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Copper Borate
is obtained by precipitating sulphate of copper with borax, washing the residue with cold water, and, after drying, igniting it, fusion being carefully avoided. In this manner, a pretty yellowish green is produced, which upon longer ignition assumes... Copper Brown
varying in hue, is obtainable, in the form of prussiate, &c., but cannot be recommended, however made. ... Copper Chrome
may be prepared by several methods, but the colour is in no case so fine as Scheele's or Schweinfurt green, nor is it as stable. ... 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 ot... Copper Stannate
or Tin-Copper Green, equals in colour any of the copper greens free from arsenic. The cheapest way of making it is to heat 59 parts of tin in a Hessian crucible with 100 parts nitrate of soda, and dissolve the mass when cold in a caustic alkali. To ... Copper Yellow
Or chromate of copper-potassa, is of a bright yellow tint, not insoluble in water. It is discoloured both by foul gas and exposure. ... Cotton Seed Blue
Cotton seed oil is bleached by treatment with either carbonate of soda or caustic lime. In both cases, a considerable residue is left after drawing off the bleached oil. This residue is treated with sulphuric acid, and distilled at a high temperatur... Damonico
or Monicon, is an iron ochre, being a compound of raw Sienna and Roman ochre burnt, and having all their qualities. It is rather more russet in hue than the pigment known as orange or burnt Roman ochre, has considerable transparency, is rich and dur... Egyptian Blue
called by Vitruvius, Coeruleum, is frequently found on the walls of the temples in Egypt, as well as on the cases enclosing mummies. Count Chaptal, who analysed some of it discovered in 1809 in a shop at Pompeii, found that it was blue ashes, not pr... 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... Frankfort Black
is said to be made of the lees of wine from which the tartar has been washed, by burning, in the manner of ivory black; although the inferior sort is merely the levigated charcoal of woods, of which the hardest, such as box and ebony, yield the best... French Prussian-brown
According to Bouvier, a colour similar to that of bistre, and rivalling asphaltum in transparency, is produced by partially charring a moderately dark Prussian blue; neither one too intense, which gives a heavy and opaque brownish-red, nor one too a... Gamboge Orange
On adding acetate of lead to a potash solution of gamboge, a rich bright orange is precipitated, which may be washed on a filter till the washings are colourless, and preserves its hue with careful drying. The orange which we thus obtained stood wel... Gambogiate Of Iron
Dr. Scoffern read a paper at the Meeting of the British Association of Science, in 1851, describing this combination as a rich brown, like asphaltum, but richer, as well as more durable in oil. It has not been, however, employed as a pigment, or at ... Gelbin's Yellow
Or chromate of lime, is a pale whitish yellow, poor in colour, partly soluble, and not at all to be depended on. ... Gold Blue
Gold purple, under the name of Purple of Cassius, was once very well known: a like compound of tin and gold may be made to yield a blue. Resembling indigo, the colour is not remarkably brilliant, and, unless several precautions are carefully observe... Gold Purple
Purple of Cassius, or Cassius's Purple Precipitate, was discovered in 1683 by Cassius of Leyden. It is a compound of tin and gold, best formed by mixing aqueous perchloride of iron with aqueous protochloride of tin, till the colour of the liquid has... 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, ... Green Bice
or Green Verditer, is the same in substance as blue verditer, which is converted into green verditer by boiling. This pigment is one of the least eligible of copper greens. ... Green Ochre
By partially decomposing yellow ochre with prussiate of potash, we have produced a fine dark blue-green, resembling Prussian green, of great depth and transparency. There are, however, difficulties in the process; and the results do not warrant us i... Green Ultramarine
is French or artificial ultramarine before the final roasting. It is a somewhat bright bluish-green, becoming a dull greenish-blue on continued exposure. Chemically, it is not a bad colour; but artists generally have decided against it. ... Hypocastanum
or Chestnut Brown, is a brown lake prepared from the horse-chestnut. This now obsolete pigment is transparent and rich in colour, warmer than brown pink, and very durable both in water and oil; in the latter of which it dries moderately well. ... Indium Yellow
Whether the new metal indium will ever be found in sufficient quantity to render it practically useful remains to be seen. The most abundant source at present known is the Freiberg blende, 100,000 parts of which only yield from twenty-five to forty ... Iodine Blue
It is curious that iodine, which gives a yellow with lead, should also afford a blue with the same metal. When a solution of iodine in aqueous soda (carbonate of soda is not so good) is added to nitrate or acetate of lead-oxide, a transient violet-r... 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. ... Iodine Yellow
Or iodide of lead, is one of those compounds whose presence on the palette should never have been allowed. Exceedingly brilliant, it is also utterly fugitive, destroyed by exposure or foul gas, and useless in admixture. We may state here that, whate... Iridium Blue
The rare metal iridium affords a blue which is a mixture of the oxide and the sesquioxide. But being slightly soluble in water and decolourised by sulphuretted hydrogen, it would not, other considerations apart, be an acquisition. ... Iron Browns
native or artificial, are well represented on the palette, but nothing would be easier than to increase their number. Of all metals, iron is the richest source of colour, capable of affording all colours with the exception of white. None of them, ho... Iron Yellow
Or oxalate of protoxide of iron, has very unadvisedly been recommended as a pigment. It is a bright pale yellow, but soon loses the beauty of its tint when submitted to air and light, becoming, by peroxidation, red and buffy. Even in a book the colo... Kermes Lake
Is an ancient pigment, perhaps the earliest of the European lakes, and ... Laque Minerale
is a French pigment, a species of chromic orange, similar to the orange chromate of lead. This name is likewise given to orange oxide of iron. ... 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 ... Madder Marrone
or Marrone Lake, was a preparation of madder, of great depth, transparency, and stability. Working well in water, glazing and drying in oil, and in every respect a good pigment, it was one of those colours which gradually--and often, as in this case... Madder Orange
or Orange Lake. It has been said that the yellows so-called produced from madder are not remarkable for stability, differing therein from the reds, purples, russets, and browns. Like them, this 'orange' is of doubtful colour and permanence, and not ...