170 ECONOMIC GEOLOGY 



Arsenic is Used in the manufacture of glass, in the manufacture 

 of certain alloys. Perhaps the most important of these is shot. 

 The presence of 1 per cent, of arsenic renders the lead more 

 fluid when heated, therefore, it more readily assumes the spherical 

 form when dropped from the shot tower. The alloy upon solidi- 

 fication is much harder than pure lead, therefore, it has greater 

 penetrating power. Its greater rotundity imparts swiftness and 

 accuracy. 



Arsenic with many metals renders them both hard and brittle. 

 This is especially true of tin. When only a few thousandths of 

 1 per cent, of arsenic is present it renders both gold and silver 

 brittle. Arsenic also hardens copper and renders it brittle. It 

 is an injurious constituent of brass. Brass with 0.5 per cent, of 

 arsenic cracks, breaks down, and will not roll. In fact it has 

 refused to roll with 0.02 per cent, present. It increases the 

 fluidity of brass, and with less than 0.02 per cent, decreases its 

 ductility. Arsenical bronzes contain from 8 to 10 per cent, of 

 arsenic. It is evident, therefore, that white arsenic comprises by 

 far the larger part of the arsenic of commerce. If other forms 

 are required as in the manufacture of colors, or in the various 

 medicinal preparations the refined forms or the arsenical prepara- 

 tions are manufactured by those parties most concerned in their 

 industrial application. 



It is often stated that the arsenic industry is fraught with great 

 danger of blood poisoning, and other evils to the employee. 

 This appears to be an exaggeration. True it is that some opera- 

 tions can be conducted only by skilled workmen, who know what 

 precautions have to be taken and how to take them. All work 

 demands care, but especially where there is dust, as in the clean- 

 ing out of chambers, in grinding the white arsenic, and in filling the 

 barrels. In these dusty operations the nostrils are kept plugged 

 with cotton wool, and in cleaning out the flues the limbs are kept 

 bandaged. In Cornwall and Devon, England, where these pre- 

 cautions are observed arsenical poisoning is rare. 



Among the new industries that have recently been developed in 

 the United States is the manufacture of white arsenic by the 

 Puget Sound Reduction Company at Seattle, Washington. The 

 Company recovers the arsenic from the Monte Cristo, Washing- 

 ton ores. In 1907 a company was incorporated at Carmel, Put- 

 nam County, New York, for mining, concentrating and exporting 

 arsenopyrite. 



