CHEMISTRY OF THE WASHOE PEOCESS. 287 



The following cliemical equations show the reactions : 



NaOl + CuOSOa = NaOSOs + OuOl 



2 CuOl + AgS = AgOl + CU2OI + S 



OU2CI + AgS = AgOl + OU2 S 



AgOl + Hg = AgHg + Hg.,01. 

 Bowring, an English metallurgist, on the other hand, denies that any of 

 sulphide of silver is chloridized, and asserts that before amalgamation takes 

 place, metallic silver is first produced. He claims that chloride of copper, in 

 contact with mercury, forms the sub-chloride of both metals. The sub-chloride 

 of copper, in contact with the oxygen of air, is converted into an oxychloride, 

 which, in turn, acts upon the sulphide of silver, and liberates the metal in a 

 free state, by oxidizing the combined sulphur. These reactions are expressed 



as follows : 



2 CuCl -h 2 Hg = OU2OI + HgaOl 

 CU2OI + = GuOl OuO 



3 (CuOl OuO) + AgS = Ag -h SO3 -f- 3 Cu^Ol. 



Although oxychloride of copper may possibly be found at times, there 

 does not appear to be any decided evidence that such is the case in practical 

 operations, or that it decomposes the sulphide of silver, while the experiments 

 already recorded show conclusively that both the chlorides of copper, under 

 favorable circumstances, do chloridize the argentiferous sulphurets. The 

 experiments, however, would seem to indicate that the action of the chloride 

 of copper was much more intense than that of the sub-chloride. 



The application and modification of the amalgamation process, as prac- 

 ticed in Washoe, has occasioned among experienced mill-men great doubt as 

 to the beneficial results derived from the use of any chemical agents, at pres- 

 ent mixed with the ore. This doubt is occasioned, or at least strengthened, 

 by the growing custom of late years of decreasing the quantity of salt and 

 sulphate of copper added to the charge, without apparently diminishing the 

 product of bullion. Many amalgamators now abstain from the use of both 

 reagents ; others add a small quantity of the sulphate of copper, but no salt ; 

 in a few instances, the custom is to throw in only a little of the latter, while 

 in many mills the rule is to employ a small amount of both substances, 

 owing to a slight prejudice against the abandonment of "chemicals" altogether. 



The action exerted by these two reagents in the pan would appear 



