302 RESOURCES OF CALIFORNIA. 
sulphuret of silver, in a gangue of gray quartz, running through 
trap and porphyritic greenstone. The lode called the Esmer- 
alda, the most prominent and apparently the mother lode of 
the district, runs with the meridian, and contains very little 
or no gold, while other leads, running at right-angles to it, con- 
tain much free gold; that is, particles of metallic gold which 
have formed no chemical union with the silver ore. The Esmer- 
alda mines were discovered in August, 1860, by J. M. Cory; 
not much of the ore has been taken out, no mills have been 
erected, little of the ore has been reduced, and therefore not 
much is known of the real wealth of the district, although little 
doubt is entertained that it will in time produce much silver. 
There are several small ditches at the Mono placers, but the 
county has no quartz-mills, and thus far no auriferous quartz 
has been discovered. 
South of Tuolumne lies Mariposa county, which is drained 
by the Mariposa and Merced Rivers. The mines are shallow 
placers and quartz. There is, I believe, not a hydraulic or 
tunnel claing in the county, and the mining-ditches are few. 
The towns are small; the population in the placers unsteady 
and irregular in their mode of life; and the county, taken as a 
whole, is considered one of the most unpleasant parts of the 
state for the home ofa family. In consequence of the scarcity 
of ditches there is no water in summer, and the placer miners 
therefore lie idle during a great part of the year, and either go 
to other counties or spend their time in dissipation. The 
county assessor reports five mining-ditches with a total length 
of forty-two miles. The quartz lodes are numerous and rich. 
There are thirty-four quartz-mills, of which four are on Fre- 
mont’s ranch; four at Coulterville; at Gentry’s Gulch and 
Whitlock Creek three each; at Agua Fria, Bean’s Creek, Bear 
valley, Burns’ Creek, Mariposa Town, Mariposa Creek and 
Stockton Creek two each; and at Bull Creek, Corbett’s Creek, 
Guadalupe, Mount Ophir, North Fork, Quartzburg, and Sax- 
ton’s Creek one exch. The Fremont ranch, which contains 
forty-eight thousand acres, is the most valuable mineral estate 
