378 ANXALS XEW YORK ACADEMY OF SCIENCES 



lion dollars. Gold, meantime, with the fall of silver, has advanced to 

 4,574,340 ounces, valued at $94,560,000. 



In the United States, we have now comparatively few distinctively 

 silver mines. Among them Tonapah, Xev., has been chief. ]\Iexico is the 

 particular home of silver, but the remarkable district of Cobalt, Ontario, 

 has given great present importance to Canada. In our own country, we 

 must expect the white metal to share the fortunes of the copper and lead 

 with which it is chiefly produced. As influencing its future, copper is a 

 more serioiis factor than lead, both for the reason that Missouri lead con- 

 tains little if any silver, and because western copper ores display greater 

 reserves than do western lead ores. As sources of silver, there were in 

 1008 no very great differences among Montana (a copper-silver state), 

 Colorado (a silver and lead-silver state) and Nevada (a silver state). 

 Utah (both a lead-silver and a copper-silver state) afforded about five 

 sixths Montana's output: and Idaho (a lead-silver state) about three 

 fourths Montana's;^ Arizona (a copper-silver state) follows after a long 

 interval, and the others are much smaller. 



As an indication of relative magnitudes, while the output of the United 

 States was placed at 52.5 million ounces in 1908, Mexico afforded 72.6 

 and Canada 22 millions. Australia with 17.3 follows and then Peru with 

 7.2 millions. A metal with so high a value as silver will stand transpor- 

 tation from remote points, and although the production in one country or 

 another may fluctuate, the world's supplies are not likely to be seriously 

 affected for many years. Silver is largely used in the metallic state, and, 

 being resistant to change, it tends to accumulate. Photography is the 

 most destructive industry to it, and when once employed in this art, it is 

 practically lost. 



Gold is mined for itself alone to a far greater degree than is silver. 

 Thus in this country in 1908, almost 93 per cent, of the gold was pro- 

 duced without regard to other metals, and only 7 per cent, was obtained 

 with copper and lead: whereas about 60 per cent, of the silver was pro- 

 duced in association with the base metals. Gold in later years has in- 

 creased in amount of production beyond all previous experience. The 

 steady and scientific digging and washing of low-grade gravels are, in the 

 long run. more productive than the rich skimmings of the early Calif or- 



1 In ounces they range : 



Montana 10..356.200 



Colorado 10.150,200 



Nevada 9,.508,o00 



Utah 8.451,300 



Idaho 7,558,.300 



Arizona 2,900,000 



