MINING. 235 
miles eastward of Sonora, in Tuolumne county, are ‘some rich 
veins of auriferous quartz, the most prominent of which are 
the Soulsby and Blakeslee lodes. The Soulsby mill produced 
forty thousand dollars in three weeks, when it commenced 
work in 1858, but it has not been so profitable of late: 
§ 214. Silver Mining—Silver mining has not yet been 
established fairly as a business in California. The silver ores 
of Washoe were discovered in 1859, and mining has been 
fairly commenced there, but the mines of Esmeralda and Coso, 
within the limits of this state, were not found until the sum- 
mer of 1860, and up the present time no mills have been 
established there. 
Silver mining differs much from gold mining. Gold is always 
found as a metal, never as an ore, and the separation from the 
accompanying vein-stone with which it is mixed mechanically, is 
much more simple and easy than the reduction of the argentif: 
erous ores in which the silver is chemically combined with 
base substances, for which it has a strong affinity. Chemical 
knowledge and chemical processes are more necessary in min- 
ing for silver than for gold ; and while all auriferous quartz is of 
the same kind, and may be treated in the same manner, there 
are many different kinds of silver ores, cach of which requires 
a peculiar treatment. The reduction of silver ore costs on an 
average, from three to five times as much as the reduction of 
auriferous quartz. 
The silver ore of Esmeralda and Coso is a sulphuret of 
silver, nearly all the veins having the same material, though the 
amount of it scattered through the vein-stone differs greatly 
in different lodes. In some veins there is much free gold, that 
i-, little specks of metallic gold which can be separated from 
the other material in the same manner that gold is separated 
from anriferous quartz. The methods of reducing silver ore 
uve so numerous and complex, and vary so much in different 
districts and under different circumstances, that it is impossi- 
ble to know now what process will be used in Esmeralda and 
Coso, the resources of which places have been so little studied. 
