AMALGAMATION, (Encycl.) The proper method of making amalgams is, by first melting the metal with as little heat as possible, and then pouring the quicksilver into it. During this operation part of the metal undergoes a kind of calcination, whence the sur-
face of some amalgams become black and dusty in a very short time. This is effectually prevented by adding a small quantity of tallow or hog's-lard to the mixture whilst hot; which restores the phlogiston lost by the metal, and preserves the mixture always of a metalline splendor. This is especially necessary in making an amalgam with zinc, which is found to excite the electrical power of glass more than any other. It requires at least four parts of zinc to one of mercury.