ELISHA MITCHELL SCIENTIFIC SOCIETY. 71 



When the gold is fully settled, the supernatant liquor is run off 

 into tanks in which scrap iron is thrown for the purpose of 

 recovering the copper in the solution. The gold precipitate is 

 scraped up, washed carefully with hot water and thrown on 

 paper filters. It is dried in stove and melted down in the 

 usual way into bullion. As a rule the auriferous sulphides in 

 North Carolina contain but little silver, and the bullion obtained 

 by this process is from 990 to 996 fine. 



By this process 90 per cent, of the assay value in gold is 

 guaranteed; the actual return is never lower than this and for 

 the most part is higher. 



No other process which has been applied to auriferous sul- 

 phides in this State has yielded such excellent results, and it is 

 hoped that a useful future is in store for it. 



Mettalurgical Laboratory, 



University of North Carolina. 



