General Observations. - When alabaster, marble, and other stones, are coloured, and the stain is required to be deep, it should be poured on boiling-hot, and brushed equally over every part if made with water; if with spirit, it should be applied cold, otherwise the evaporation, being too rapid, would leave the colouring matter on the surface, without any, or very little, being able to penetrate. In greyish or brownish stones, the stain will be wanting in brightness, because the natural colour combines with the stain; therefore, if the stone be of a pure colour, the result will be a combination of the colour and stair In staining bone (or irory, the colours will take better before than alter polishing; and if any dark spots appear, they should be rubbed with chalk, and the article dyed again to produce uniformity of shade. On removal from the boiling-hot dye-bath, the bone should be immediately plunged into cold water, to prevent cracks from the heat. If paper or parchment is stained, a broad varnish brush should be employed to lay the colouring on evenly. When the stains for wood are required to be very strong, it is better to soak and not brush them; Therefore, if for inlaying or fine work, the wood should be previously split or sawn into proper thicknesses, and when directed to be brushed several times over with the stains, it should be allowed to dry between each coating. When it is wished to render any of the stains more durable and beautiful, the work should be well rubbed with Dutch or common rushes after it is coloured, and then varnished with seed-lac var-nish,or if a better appearance is desired, with three coats of the same, or shellac varnish. Common work only requires frequent rubbing with linseed oil and woollen rags. The remainder, with the exception of glass, will be treated of in this paper.
359. Alabaster, Marble, and Stone, may be stained of a yellow, red, green, blue, purple, black, or any of the compound colours, by the stains used for wood.
1. Lay the "articles for several hours in a strong solution of nitrate of silver, and expose to the light. 2. Boil the article for some time in a strained decoction of logwood, and then steep it in a solution of per-sulphate or acetate of iron. 3. Immerse frequently in ink, until of sufficient depth of colour.
1. Dip blue-stained articles for a short time in nitro-hydro-chlorate of tin, and then in a hot decoction of fustic. 2. Boil in a solution of verdigris in vinegar until the desired colour is obtained.
J. Dip the articles first in the tin mordant used in dyeing, and then plunge into a hot decoction of Brazil wood - half a pound to a gallon of water - or cochineal. 2. Steep in red ink until sufficiently stained.