286 RESOURCES OF CALIFORNIA. 



Besides it is said that new processes for reducing silver ore 

 have been invented, far superior to all the old methods ; and 

 these processes are kept secret. It is therefore unnecessary 

 that I should go into a long description of the various pro- 

 cesses practised elsewhere. Silver ore after pulverization is 

 smelted by mixing with it fifty per cent, of lead in metal or 

 ore, and ten per cent, of iron, and exposing the whole to a 

 heat sufiicient to melt the silver which runs off. The metal 

 thus obtained is not pure but contains much lead, which is 

 driven off by heat while the silver is kept in a molten condition 

 for a period of four or six hours. The cost of smelting in 

 California at present, is about one hundred and twenty-five 

 dollars per ton. In most of the other methods of reducing 

 silver ore, the ore is roasted to drive oflT the sulphur. In the 

 barrel amalgamation, which has been used at Washoe, and will 

 probably be used at Esmeralda also, half a ton of ore, after 

 being pulverized and roasted, three hundred j)ounds of water, 

 and one hundred pounds of wrought iron, in little fragments, 

 are put into a barrel, which revolves on a perpendicular axis. 

 At the end of two hours the mass has taken the consistence of 

 thick cream, when five hundred pounds of quicksilver are put 

 in, and after the barrel has revolved four hours more, the 

 amalgamation is complete. More water is now poured in ; 

 the barrel revolves very slowly to let the amalgam all settle to 

 the bottom, the mud runs ofi* through a cock four inches above 

 the bottom, and the mercury and amalgam are then drawn off 

 through a little hole in the bottom of the barrel. 



§ 215. Quicksilver Mining. — The ore from which quick- 

 silver is obtained is a sulphuret. The sulphur is driven off by 

 heat, and the metal, which rises in fumes from the ore, is col- 

 lected by condensation. The miners are Cornishmen and 

 Mexicans. The ore is in large masses underground, not in a 

 connected vein of regular thickness ; and after one mass is ex- 

 hausted, much labor is often vainly spent in search of another. 

 There are, however, usually little seams of ore running from 

 one large deposit to another, and it is the business of the 



