ECONOMICS 2!', 



Soft lead represents the production of the smelters in the 

 Mississippi Valley \vhere the ores are almost I'm- from silver, 

 nnly one of the smelters in this district desilverizes its lead. 

 However, a considerable quantity of soft lead ores have been 

 annually smelted by various silver-lead smelters. A little soft 

 lead ore is annually derived from Washington and other western 

 states. 



Refined lead embraces all of the desilverized lead produced in 

 this country and the pig lead recovered from the Mississippi 

 Valley lead industry. 



Antimonial lead, or hard lead, is derived from the treatment of 

 the gold and silver ores bearing antimony. The antimony 

 combines with the lead as antimonial lead. The two metals are 

 never separated, and there is a large demand for this product. 



There are two lead pigments produced directly from various 

 plumbiferous ores, namely, sublimed white lead and sublimed 

 blue lead. The former consists of lead sulphate 75 per cent., 

 lead oxide 20 per cent., and zinc oxide 15 per cent. The latter 

 consists of lead sulphate varying from 50 to 53 per cent., lead 

 oxide 41 to 38 per cent., together with small proportions of lead 

 sulphide, lead sulphite, and zinc oxide. Zinc-lead oxide con- 

 tains from 46 to 50 per cent, of lead sulphate, frem 32 to 46 per 

 cent, of zinc oxide, and a small amount of zinc sulphate. 

 Leaded zinc oxide varies from 4 to 20 per cent, in its lead sulphate 

 content, while the remainder is zinc oxide together with a small 

 proportion of zinc sulphate. The total lead content from 

 domestic ores averages between 7000 and 8000 short tons. 



Missouri is the first producer of lead followed by Idaho, Utah, 

 and Colorado in the order of their importance. The United 

 States produced approximately twice as much lead as any other 

 country, followed by Spain, Germany and Mexico each of which 

 produces more than 100,000 metric tons. 



MERCURY 



Production. The unit of measure for mercury is different 

 from that of the other metals. The liquid metal is put up in 

 flasks. Each flask contains 75 Ib. The market at San Francisco 

 determines the price. The average price per flask for 1912 was 

 $42.04. This represents a total value of $1,057,180 for the 

 1912 production. 



