SHEET METALS 455 



metals, while a composition of yellow ocher, Prussian blue, 

 and lampblack dissolved in glue water is used for wood, 

 plaster figures, etc. 



536. Bell-Metal. Bell-metal is a compound of tin and 

 copper, which becomes not only more sonorous, but heavier 

 than either of the separate ingredients which compose it. 

 While the proportions of tin and copper in the compound 

 differ, ordinarily 23 Ibs. of tin are mixed with 100 Ibs. of 

 copper, the latter being somewhat increased if the bells are 

 large. Brass, spelter, and even lead are sometimes added. 

 Silver, which much improves the tone of the metal, is infre- 

 quently used. 



537. Britannia Metal. Britannia is an alloy metal 

 composed of block tin, a small portion of antimony, and less 

 than one-third as much copper as brass. This compound 

 which is bright and silvery looking, is now extensively used 

 instead of pewter, and for many purposes to which- pewter 

 was never adapted. It is very easy to work by rolling, 

 casting, turning, and planing, as well as by stamping in 

 dies. Consequently, the articles made from it are almost 

 unlimited in variety and very cheaply produced. Teapots, 

 candlesticks, and spoons are some of the articles frequently 

 made of this metal. 



538. Arsenic. Arsenic is used in many metallic alloys, 

 Its various oxides are important ingredients in different 

 dyes. It is employed as a flux for glass, and it produces many 

 kinds of coloring in glass. It is a virulent poison in all its 

 forms, though employed as a medicine in proper solutions, 

 The arsenic of commerce is a white oxide of the metal, 



