These are sometimes made with fusible metals; sometimes with non-metallic compounds, having their surface covered with a conducting substance. The fusible metal is composed of 8 parts of bismuth, 3 of tin, and 5 of lead. The French clichee moulds consist of 8 parts of bismuth, 4 of tin, 5 of lead, and 1 of antimony. These are repeatedly melted together till perfectly mixed; and after being poured out on a suitable surface, are well stirred, and the medal forcibly pressed on the compound at the moment it is about to become solid. Composition Moulds are made with 8 oz. of spermaceti, 1 3/4 oz. of white wax, and the same of strained mutton suet. These are melted together, and a little fine plumbago or flake-white, stirred in. To copy plaster casts, the cast is set in a plate of hot water, with its face above the water, till it has absorbed water; it is then surrounded with a ring of cardboard, and the melted composition poured on it. The composition mould requires to be brushed over with finely powdered genuine black-lead.