Ferrate Of Baryta
: ON THE PRIMARY, RED.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 deg. C.," and to be only "tolerably stable."
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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 ... Cobalt Green
Rinman's Green, Vert de Zinc or Zinc Green. True cobalt green is made by igniting a very large quantity of carbonate of zinc with a very small quantity of carbonate of cobalt. To give a green tint to an enormous proportion of the former, an inapprec... Cobalt Marrone
There is obtainable from cobalt a very rich marrone brown, which, like many other colours, is more beautiful while moist than when dried. Permanent, if carefully made and most thoroughly washed, it is an expensive compound, and must rank among those... Cobalt Prussian Blue
Gmelin states that yellow prussiate of potash yields with a solution of oxalate of sesquioxide of cobalt a blue resembling Prussian blue--that, in fact, there can be obtained a Prussian blue with a base of cobalt instead of iron. In the moist state,... Cobalt Purples
are obtainable ranging from the richest crimson purple to the most delicate violet. We have produced them by wet and dry methods, varying in brilliancy and beauty, but characterised generally by want of body, and frequently by a smalt-like grittines... 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... Coffee Black
though little known and not on sale, has been strongly recommended by Bouvier as one of the best blacks that can be used. Soft without being greasy, light, almost impalpable, even before being ground, it gives tints of a very bluish gray when mixed ... Copper Blues
are now seldom or never employed as artists' pigments. The following are the principal varieties:-- ... 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...