368 Keiv Method of feparatlng Silver, ^e. 



that a proper degree of heat could be given to the bafon and 

 the fudd metal. The hrcifque being very dry, a quintal of 

 our billon money was fufed in the bafon through charcoal ; 

 and the charcoal being then removed from the top, a work- 

 man, furniflied with a long iron fpoon, threw fulphuron the 

 melted mafs, while another workman ftirred the matter with 

 a clay rod. In proportion as fulphuiet of copper was formed, 

 the furfacc of the mals was fprinkled with a bru(h dipped in 

 water, and another workman, with an iron fork, removed 

 in plates ihe maltes as thev became fixed. There was ob- 

 tained in this manner, after the operation, a cupreous but- 

 ton, and maites nearly in the fame proportion, and contain- 

 ing the fame quantity of filver, as in the trials on a fmall 

 fcale. A quintal and a half of matter was thus fuftd at 

 once, and it is probable that a greater quantity might be 

 fufed in the fame manner. 



The maltes, well pulverized, were fubie<^led to calcination 

 with muriate of foda and linie in a cupelling furnace ar- 

 ranged for that purpofe. 



After a calcination of ten hours, the matter was amalga- 

 mated in one of thofe mills commonly nied in the mini fof 

 extracling filver and gold from the refufe of different oj^era- 

 tions. After the firll amalgamation, which laltcd only 14 

 hours, the third part of the filver contained in the oxide was 

 extrafted ; and, as it is in the fecond amalgamation that thfc 

 greater part of the filver is attacked by the mercury, we maj?^ 

 conclude, without any danger of being deceived, that three 

 amalgamations will be more than futticient to cxtrait, on a 

 large fcale, the whole filver of the mattes. 



Thefe mills, which contain from 36 to 30 pounds of mat- 

 ter, may be put in aclion, to the number of forty, by a finjrlfe 

 water-wheel : befides this advantage, their capacity may be 

 augmented. 



By the procefs of C. Napionc, not only filver but the gold 

 united with it may be extracted from argentiferous copper) 

 and this may be done by one liquation. 



As the water of the wafhingof the firfl: amalgamation con- 

 tains a great deal of fulphate of copper, the metal may be 

 extracted from it [>y cementation with iron, or by precipi- 

 tating it by carbonate of potaih, which will produce cupreous 

 carbonate of a l)right green colour. The ianie water after- 

 wards evaporated gives fulphate of foda in abundance. 



The water ot the fecond wafliing and the third amalgama- 

 tion is colourlefs ; and there may be extraiHcd from it, with 

 advantage, by evaporation, muriate and carbonate of foda. 



The oxide of copper freed from the filver may be fent to 

 • • the 



