BRASS (AS. bras, probably related to Icel. brasa, to harden by fire, Sw. brasa, to fire). An alloy of copper and zinc, considered the most important of all alloys. It was distinctly known to the ancients, as shown by its mention in the Old Testament and in the works of Pliny; though, according to some authors, the alloy of the ancients was a variety of bronze, or a mix ture of copper and tin. Natural brass was early used and was known as orichaleum. During the Middle Ages brass was made in Germany, chiefly in sheets, which found extensive use in churches. The original method for its produc tion, called the e,mentation process. was by heating copper in the form of shot or sheet in crucibles in contact with zinc. or as calamine and carbon, resulting in the volatilization of the zinc, and its subsequent absorption by the copper. The brass thus obtained was melted clown and cast. In 1781 a process for the direct production of brass from copper and zinc was patented by James •nunerson, whose method has since entirely superseded the old process, owing to its greater simplicity. Ernmerson's method consists essentially in first melting the copper in a crucible, then adding the zinc in small quantities. and stirring until the two metals are thoroughly mixed. after which the molten brass is east into molds of sand or iron. Brass has a fine yellow color, which becomes darker as the proportion of copper is increased, and is callable of receiving a fine polish. It is harder than copper, and hence better adapted to resist wear. Brass is both malleable and ductile, and there fore may be rolled into thin sheets or drawn into fine wire. It resists the influence of the atmosphere better than copper, but tarnishes if not protected by a lacquer or varnish. Brass
comes into commerce chiefly as cast, sheet, wire, and tubes. The proportions of its two con stituents vary from 10 parts of copper and 1 of zinc, forming a reddish-yellow brass, all the way to 1 part of copper and 5 parts of zinc, forming a very dark gray alloy. The composition of brass is regulated with a view to the purpose for which the alloy is to be employed. •The pro portions of the more important kinds are as follows: Button brass. S parts copper with 5 parts zinc; fine brass, 2 parts copper with 1 part zinc; fine casting brass, 90 parts copper. 7 parts zinc, 2 parts tin, and 1 part lead: gilding brass, 64 parts copper, 32 parts zinc. :3 parts lead, 1 part tin; malleable brass, 3 parts copper with 2' parts zinc: soldering brass, 12 parts fine brass, 6 parts zinc, 2 parts lead; wire brass, 72 parts copper. 28 parts zinc. Some of the most impor tant kinds of brass have special names; thus, dick's metal is brass composed of GO parts cop per, 38.2 parts of zinc, 1.S part iron: bath metal is 5 parts of copper and 1 part of zinc; Bristol brass, 61 parts of copper, 39 parts of zinc; oroidc, or French gold. 9 parts copper, 10 parts zinc: Mannheim gold, 2 parts of copper. 114 parts zinc; Muntz's metal, 19 parts copper and 12 parts zinc; Pinchbeck, SS.S parts copper, 112 parts zinc; Prince's metal, 75 parts copper and 25 parts zinc; similar, from 6 to 9 parts of cop per with 1 part of zinc. An excellent brass solder consists of equal parts of copper and zinc, 1 part of silver being added for finer kinds of work.