

USEFUL METAL* 175 



mosphere bettor than many other alloys, or the pure metals 

 thnn.selves. If the proportion of antimony is increased the 

 alloy is proportionately harder, but ronvspoiidiiiKly uc:ik.-r in 

 tenacity and elasticity. If the antimony exceeds 10 per n-nt. 

 the alloy crystallizes in beautiful laminae. Both the melting 

 point and the ease of corrosion increases with the antimony and 

 strikes a maximum at the true aluminum antimonide, Al 2 Sbj. 

 Its melting point is higher than that of steel but the melting 

 point of its constituents is very low. It is not attacked by dry 

 air at the ordinary temperatures, but at the higher temperatures 

 it is oxidized. Under the influence of moist air at high tempera- 

 tures the alloy is readily decomposed. If the per cent, of anti- 

 mony be still further increased both the melting point and the 

 corrodability of the alloy are proportionately decreased. The 

 antimony aluminum alloy readily combines with other metals 

 forming a complex series, some of which are susceptible of a high 

 polish and capable of industrial application. The aluminum, 

 nickel and antimony alloys and the tungsten, silver and antimony 

 alloy are exceedingly important and remarkable for their intense 

 hardness, tenacity and elasticity. The alloys of antimony with 

 silver, aluminum, nickel and copper are susceptible of a high 

 polish and capable of wide industrial application. The alloys of 

 antimony with iron and steel, with or without nickel and chro- 

 mium, are extremely fine grained, absolutely free from flaws, 

 hard and tenacious. With copper alone 1 part of antimony 

 in 1000 parts of the red metal will destroy all of its beneficent 

 effects. With copper, it is one of the most dreaded of all impuri- 

 ties as it occasions cracks in the rolling of the metal. It also is an 

 injurious constituent in the brasses and bronzes. 



Antimonial lead or hard lead is an alloy of the two metals 

 indirectly derived from the treatment of antimonial gold and 

 silver ores. For antimonial lead there is a good demand. Much 

 antimony in commercial tin, zinc, arsenic, and copper reaches 

 the market as a by-product in the metallurgy of base bullion 

 and is sold direct as an alloy. 



Antimony is used in dying as a mordant for vegetable colors. 

 It is used also in medicine. The most common form is known 

 in commerce as tartar emetic, a tartrate of antimony and potas- 

 sium. It has caused death when applied to the skin as a local 

 irritant or vesicant. It has a nauseous and metallic taste. 

 The sulphide, SbjSs, has also been used in medicine. It is also 



