MINING. 239 



nature of the material in which they are found. In placer 

 mining, the earthy matter containing the gold, called the " pay- 

 dirt," is washed in water, which dissolves the clay and carries 

 it off in solution, and the current sweeps away the sand, gravel, 

 and stones, while the gold, by reason of the higher specific 

 gravity, remains in the channel or is caught with quicksilver. 

 In quartz mining the auriferous rock is ground to a, very fine 

 powder, the gold in which is caught in quicksilver, or on the 

 rough surface of a blanket, over which the fine material is 

 borne by a stream of water. About two-thirds of our gold is 

 obtained from the placers, and one-third from the quartz. 



A mine is defined and generally understood to mean " a 

 subterraneous work or excavation for obtaining metals, metallic 

 ores or mineral substances ;" but this definition does not apply 

 to our placer mines, which are places where gold is taken from 

 diluvial or alluvial deposits. Most of the work is not subter- 

 raneous ; it is done in the full light of day. In some of the 

 claims the pay-dirt lies within two feet of the surface ; in 

 others it lies much deeper, but all the superincumbent matter 

 is swept away. 



"Water is the great agent of the placer miner ; it is the ele- 

 ment of his power ; its amount is the measure of his work, 

 and its cost is the measure of his profit. With an abundance 

 of water he can wash every thing ; without water he can do 

 little or nothing. Placer mining is almost entirely mechanical, 

 and of such a kind that no accuracy of workmanship or scien- 

 tific or literary education is necessary to mastery in it. Amal- 

 gamation is a chemical process it is true, but it is so simple 

 that after a few days' experience, the rudest laborer will man- 

 age it as well as the most thorough chemist. 



It is impossible to ascertain the amount of gold which 

 has been taken from the mines of California. Records have 

 been kept of the sums manifested at the San Francisco Custom 

 House, for exportation, and deposited for coinage in the mints 

 of the United States ; and there is also some knowledge of 

 the amounts sent in bars and dust to England ; but we have 



