284 KESOURCES OF CALIFORNIA. 



§ 212. Sulphurets. — Many auriferous quartz veins contain 

 considerable quantities of sulphurets or pyrites of iron, cop- 

 per and lead, and their presence prevents amalgamation, and 

 thus causes a great loss of gold. It is said that on some occa- 

 sions in good mills, not more than twenty or thirty dollars 

 have been obtained from a ton of vein-stone which had seven 

 or eight hundred dollars of gold in every ton. The best 

 method of treating the quartz containing pyrites, is to roast it, 

 and thus drive off the sulphur, but this process is so expensive 

 that it is seldom used ; and the common practice is to crush 

 and amalgamate the rock, and save the concentrated tailings for 

 some future time, when there may be a sale for them, or when 

 it will be cheaper to reduce them. The pulverized sulphurets 

 are decomposed by exposure to the air, and after the tailings 

 have been preserved for a time, they may pay better at the 

 second amalgamation than at the first. A mixture of common 

 salt assists the decomposition of the pyrites. 



§ 213. Chief Quariz-JSIilh. — The most productive quartz- 

 mill in the state is the Benton mill, on Fremont's Itant-h, in 

 Mariposa county. It is also the largest, having forty-eight 

 stamps. There are four mills on the esta.te, with ninety-one 

 sta;n[)S in all, and their average yield per month is sixty thou- 

 sand dollars. A railroad four miles long conveys the quartz 

 from the lode to the mills. The Allison quartz mine in Nevada 

 county produces forty thousand dollars per month. The Sierra 

 Buttes quartz-mill, twelve miles from Downieville, yields about 

 lifteen thousand dollars per month. These last mills run 

 night and day, and crush and amalgamate ten thousand tons 

 of rock a year or tAventy-eight tons per day. Forty men are 

 employed, twenty-five to quarry the rock, five in the mill to 

 attend to the stamps and amalgamation, one to do carpentry, 

 one for blacksmithing, and eight for getting out timber, trans- 

 porting qua^'tz, and so forth. The cost of quarrying, crush- 

 ing, and amalgamating a ton of rock is six dollars. The wages 

 of the men are from fifty to seventy dollars per month wiih 

 boarding. The average wages is sixty dollars About ten 



