1. Gold, not being subject to intrinsic change by atmospheric action, or by that of common chemical agents, is extensively used in gilding various substances, either with the view of preserving them from decay, or for the purpose of embellishment. To prepare the gold for application in this manner is the business of the gold-beater.
2. The metal is first melted with some borax in a crucible, and formed into an ingot by pouring it into an iron mould. The mass is next hammered a little on an anvil, to increase the cohesion of its parts, and afterwards repeatedly passed between steel rollers, until it has become a riband as thin as paper.
3. Two ounces and a half of this riband are cut into 150 pieces of equal dimensions. These are hammered a little to make them smooth, and then interlaid with pieces of fine vellum four inches square. The whole, with twenty other pieces of vellum on each side, is inclosed in two cases of parchment. The packet is then beaten on a marble anvil with a hammer weighing sixteen pounds, until the gold has been spread to near the size of the vellum leaves, it, in the mean time, being often turned over.
4. The gold leaves are next divided into four equal squares, with a steel knife on a leather cushion; and the 600 leaves thus produced, are interlaid with a kind of leather or parchment made of the intestines of the ox, and beaten with a hammer weighing twelve pounds, until the leaves have been extended as before. They are again quartered and interlaid, and beaten with a hammer weighing six or eight pounds.
5. The gold having now been sufficiently extended, the packets are taken apart, and the leaves cut to a proper and uniform size, by means of a cane frame on a leather cushion. The leaves, as fast as they are trimmed, are placed in a book, the paper of which has been covered with red bole, to prevent the gold from sticking. Of the two ounces and a half of gold thus treated, only about one ounce remains in perfect leaves, which, altogether, amount to 2000 three inches and three-eighths square. The books contain twenty-five leaves, so that one ounce of gold makes eighty books.
6. Gold extended into leaves, is alloyed, in a greater or less degree, with silver or copper, or both, because, in a pure state, it would be too ductile. The newest skins will work the purest gold, and make the thinnest leaf, because they are the smoothest. The alloy varies from three to twenty-four grains to the ounce, but in general it is six, or one part of alloy to eighty of gold.
7. A kind of leaf called party gold, is formed by the union of a thin leaf of gold and a thicker one of silver. The two are laid together, and afterwards heated and pressed, until they have cohered. They are then beaten and otherwise treated, as in the process just described. Silver, and likewise copper, are also beaten into leaves, although they will by no means bear so great a reduction as gold. Considerable quantities of copper leaf are brought from Holland, which in commerce is known by the denomination of "Dutch leaf," or "Dutch gold."
8. The ancient Romans were not ignorant of the process of gold-beating, although they did not carry it so far as we do. Pliny informs us that they sometimes made 750 leaves four fingers square, from an ounce of gold. At Præneste was a statue of Fortune, gilt with leaves of a certain thickness; hence those beaten to the same degree of thickness were called Prænestines. Those of another and less degree of thickness, were called quæstoriales, for a similar reason.
9. The Romans began to gild the interior of their houses immediately after the destruction of Carthage. The wainscots of the Capitol were first ornamented in this manner; and afterwards it became fashionable to gild the walls and ceilings of private dwellings, as well as articles of furniture.
10. Gold wire.—The ductility of gold is more conspicuous in wire than in leaves. The wire thus denominated, is in reality silver wire covered with gold. It is formed by covering a silver rod with thick leaves of gold, and then drawing it successively through conical holes of different sizes, made in plates of steel. The wire may be reduced, in this manner, to a degree of extreme fineness, the gold being drawn out with the silver, and constituting for it a perfect coating.