Thallium Red
: ON THE PRIMARY, 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.
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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 v... 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. ... Roman Green
brought from Rome some years back by a President of the Royal Academy, appeared to be a mixture of Prussian blue and Dutch or Italian pink. It was a fugitive compound, which became blue in fading. ... 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 me... Rouge
The rouge vegetale 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 di... Rubens' Brown
still in use in the Netherlands under this appellation, is an earth of a lighter colour and more ochrous texture than the Vandyke brown of English commerce: it is also of a warmer or more tawny hue than the latter pigment. Beautiful and durable, it ... Rufigallic Red
When a duly proportioned mixture of gallic acid and oil of vitriol is carefully and gradually heated to 140 deg., a viscid wine-red liquid results. If this be poured into cold water, after cooling, a heavy brown-red granular precipitate is formed, s... 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:--T... Sandal Wood Purple
Sandal wood contains about 16 per cent. of colouring matter, soluble with difficultly in water, but readily dissolved by alcohol. From the latter solution, chloride of tin throws down a purple, and sulphate of iron a deep violet precipitate; neither... Saunders Blue
... Schweinfurt Blue
or Reboulleau's Blue, is prepared by fusing together equal weights of ordinary arseniate of protoxide of copper and arseniate of potash, and adding one-fifth its weight of nitre to the fused mass. The result is, so to speak, a sort of blue Scheele's... Silicate Of Baryta
One part of silica heated to whiteness with three parts of baryta, yields a pale green solid mass, permanent, but deficient in colour when ground. It might be employed in enamelling. ... 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. ... 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,... Spanish Black
or Cork Black, is a soft black, obtained by charring cork, and differs not essentially from Frankfort black, except in being of a lighter and ... Thallium Orange
is produced when bichromate of potash is added to a neutral salt of the protoxide of thallium, as an orange-yellow precipitate. The scarcity of the metal precludes their present introduction as pigments, but if the chromates of thallium were found t... 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 pa... Thallium Yellow
The new metal thallium yields in combination with chromic acid two yellow colours, a pale and an orange. They are not absolutely insoluble in water, and the sulphide of thallium being brown, would probably be damaged by impure air. But whatever thei... Thwaites' Yellow
Under this name chromate of cadmium was introduced some few years back. If well prepared, it is a fine soft powder of a very vivid light yellow colour. The compound is too soluble, however, to be of value, its washings even with cold water being con... 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 a... Tin Violet
By heating chromate of stannic oxide to bright redness, a dark violet mass is obtained, which is better adapted to enamel painting than to the palette. It communicates in glazings a variety of tints, from rose-red to violet. * * ... 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. ... Titanium Green
has been proposed as a substitute for the green arsenical pigments in common use; but, apart from its expense, the colour is very inferior to Scheele's green, &c. Titanium green is a ferrocyanide of that metal, produced by adding yellow prussiate of... Tungsten Blue
is an oxide formed by the action of various deoxidizing agents on tungstic acid. It remains unaltered in the air at ordinary temperatures, is opaque, and of a blackish indigo-blue colour. As a pigment, there is little to recommend it. ... Turbith Mineral
... 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 makin... Uranium Brown
Yellow, red, orange, green, have been previously noticed as being derived from uranium, and to this list of colours may now be added brown. A warm rich hue of the utmost intensity may be produced, which possesses considerable permanence, although no... Uranium Green
is an oxide of a deep dull green colour, inclining to olive, and nearly black when in lumps. A durable but unattractive preparation, equalled in permanence and far surpassed in beauty by many cheaper compounds. ... Uranium Orange
is obtainable by wet and dry methods as a yellowish-red, or, when reduced to powder, an orange-yellow, uranate of baryta. It is an expensive preparation, superfluous as a pigment. ... 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 ... Uranium Yellow
Can be produced of a pale or orange tint, differing in brightness and depth of colour according to the mode of preparation. It is fairly eligible as a pigment, and far superior to the many fugitive compounds which have from time to time appeared. Be... Vanadium Green
falls when ferrocyanide of potassium is added to vanadic acid dissolved in a strong acid. It is a beautiful green precipitate, but at present simply a curiosity, owing to the rarity of the metal vanadium. * * * * * ...