(a) Verdigris, 8 oz.; flowers of zinc or tutti powder, 4 oz..; borax and nitre, of each 2 oz.; corrosive sublimate, 2 drachms, made into a paste with oil, and melted together. Used in the commoner kinds of tea-boards, etc.
(6) Dissolve copper in aquafortis until it is saturated, and then put into the solution some small pieces of iron, when the copper will be precipitated in the metallic state; the fluid must then be poured 'off, and the powder carefully washed, dried, and levigated, when it may be put by for use.
(c) Bronze powder is sometimes made from Dutch gold, which is sold in books at a very low price. All these inferior bronzes require to be covered with a coat of clear varnish, or they will very soon lose their metallic appearance, nor will the varnish entirely prevent, although it will greatly retard, this change.
Melt together, in a crucible over a clear fire, equal parts of sulphur and the white oxide of tin. Keep them continually stirred with the stem of an earthenware pipe or glass rod, till they assume the appearance of a yellow flaky powder. An iron rod must not be used in stirring up any mixture of sulphur when melted, or the sulphur and iron will unite. It is rubbed on with the finger.
Another way to prepare it is to take quicksilver, tip, sulphur, and sal ammoniac, equal parts. First melt the tin, then pour the quicksilver into it, afterwards grind up with the amalgam thus made the sulphur and sal ammoniac. Place the mixture in a crucible, and heat until the powder in the crucible becomes gold-coloured, and also until no fumes of quicksilver arise.
Leaf gold is ground with virgin honey on a stone, until the leaves are broken up and minutely divided. The mixture is removed from the stone by a spatula, and stirred up in a basin of water, whereby the honey is melted and the gold is set free; the basin is then left undisturbed until the gold subsides; the water is poured off, and' fresh quantities are added until the honey is entirely washed away; after which the gold is collected on filtering paper, and dried for use.
Bismuth and tin, of each 2 lb.; melt together and add 1 lb. of quicksilver. Pound all together into a powder. This soft fusible amalgam is used as an imitation of silver bronze for plaster figures and other common purposes, in the same way as the aurum musivum is for gold-coloured articles. It may be used as spangles in sealing-wax; it must then be mixed when the resinous part of the wax is getting cold.