122 Iron. probably owing to a fmall portion of phos phoric acid, as other iron melted with phos phate of iron, becomes evidently brittle. The iron obtained from pyrites, is more readily foluble in acids, and more magnetic; it is malleable in white heat, arid alfo when cold, but it is brittle when red hot. Steel is harder dr an iron, more elaftic, not .eafily a&ed upon by acids, and takes a higher polifh. The brown iron ores, which contain a fmall portion of mangancfe, are found to be the beft for the procefs of making fteel. This proccfs is very fimple ;—bars of iron are placed in a ftratified manner with charcoal, and ex- pofed to a white heat, after which, they are reduced to thinner plates, and hardened by putting them fuddenly into cold w'ater. Or i z or 15 pieces of iron plates are foldered together, after being expofed to a white heat; they are then hammered and extended again into bars, See. In certain parts of Germany, it is done by cementation, that is, by placing iron in a ftratified manner, with a mixture of 16 parts of lamp-black, 8 parts of charcoal, 8 of afhes, and 5 of muriate of foda. GENUS