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FACTS IN AMERICAN MINING. 



By S. L. Bensusan, Esq. 



[Read before Ihe Royal Society, 2 Jime, 18'/ 5.] 



In this paper I propose to call attention to what has been done 

 in America, in the way of improvements in methods and processes 

 of mining — in the improved apparatus and appliances employed— 

 to give data showing the great results achieved with material and 

 by processes with which we are comparatively unacquainted — 

 point out some of the conditions in which gold, silver, and other 

 metals are found and worked— give sketches of some of the great 

 works undertaken, and their results — and, generally, any other 

 matter that may present itself worthy of note and believed to be 

 not generally known. "Whilst endeavouring to confine myself as 

 much as possible to new matter, I doubt not that many will find 

 in the paper material with which they were previously acquainted, 

 a circumstance unavoidable in any case. 



Some years since, the American Government appointed a Com- 

 mission to investigate and report upon the condition of the mining 

 industry in the Western States of America ; to this report I am 

 indebted for much of the material in this paper. The report of 

 the Commission contains not only many facts of great scientific 

 interest, but so many valuable inferences are deduced, and such a 

 thorough acquaintance with the subject is displayed, that there is 

 little left to be done beyond culling the matter of interest and 

 presenting it in a useful form. 



For convenience of reference the subject will be divided under 

 the following heads, viz. : 1. Mode of occurrence. 2. Methods of 

 mining. 3. Treatment of metals. 4. Statistics. In the present 

 paper I shall deal only with gold and silver. 



Mode op occurrence. 



Gold, silver, and an alloy of these metals, occur in quartz reefs, 

 frequently largely mixed with copper, lead, zinc, antimony, arsenic, 

 iron, sulphur, &c. 



Loose slate. — Near Sacramento and elsewhere large bodies of 

 loose slate occur, containing pyrites. The material is soft, and 

 eight tons per day are crushed with each stamper. The value of 

 the yield is only 20s. to 25s. per ton, but such is the supposed value 

 of such property that half-interest in the Sacramento mine was 

 sold for £35,000. 



