160 SILVEB-LEAD DEPOSITS OF EUEEKA, NEVADA. 



Composition of charge and analyses of slag and speiss. The analysis of the Richmond 



ore shows less than 3 per cent, of silica and about 30 per cent, of iron sesqui- 

 oxide. In order to make a slag with sufficient silica for good smelting, 

 quartzose ores are added, or quartzite when such ores are not to be obtained. 

 The slag and speiss, analyses of which by Mr. F. Claudet are annexed, re- 

 sulted from smelting the ore, an analysis of which by the same chemist is 

 given on page 60. The material furnished Mr. Claudet is stated to have 

 been the regular daily samples taken throughout an entire year. 



SPEISS. 



Per cent. 



Arsenic 32.95 



Antimony 13 



Molybdenum 2.81 



Sulphur 3.34 



Lead 2.18 



Copper 1.06 



Iron 57.02 



Zinc 07 



Lime 34 



Silica 23 



Silver and gold 029 



Silver, per ton of 2,000 pounds, 8.01 ozs.; gold, 0.43 oz. 



SLAG. 



Per cent. 



Silica 23.67 



Iron protoxide . . - 58.32 



Alumina 1.64 



Lead oxide 3.51 



Metallic lead 3.26 



Bismuth 



Copper oxide 1.08 



Zinc oxide 4.44 



Manganese oxide 23 



Molybdenum 32 



Arsenic . . 25 



Antimony 



Sulphur 2.19 



Lime 4.78 



Magnesia 1.27 



Silver, 0.58 oz. to, the ton of 2,000 pounds; gold, trace. 



