alloyed with Copper in Bullion. 267 



fo as to be able to refine it immediately by cupellstion, and 

 to obtain at the iamc time fconce, Icfs rich, fur amalgam- 

 ation. 



' The experiments which he relates prove that he was not 

 deceived in his expeftation. He look a pound and lix ounces 

 of argentiferous copper of the quality of 3 ^ deniers the marc, 

 and, "having fufed it in a crucible, mixed with it two ounces 

 of fulphur. "Having feparated the matte ox {con:&, he repeated 

 the fame operation twice on the cupreous re gulus; and alter 

 the three operations he obtained i pound 5 ounces and 23 

 deniers of wzri//c', and 4 ounces 16 deniers and 12 grains of 

 metallic rcgulus, which, though pretty ductile, fplit at the 

 edijes when tiatlened with the b.anuner. 



The trial made on viattes or fcorice of three meltings united, 

 r.iowed that they contained only 11 pounds 3 ounces of filver 

 in the docimailic quintal, and the quality of the rcgulus was 

 7 deniers 16 grr.ins per marc; a quality at which it may be 

 fubjected to c-iipellation without any other procefs. 



After havino- well pulverized the mattes, and mixed with 

 them muriaie^of foda in the proportion of 12 to 100, and 

 the fame quantity of quicklime, and after calcining it for 

 four hours under a muffle, he amalgan^ated the mixture. 

 1 he rehilt of this amalgamation and of a fnbfcquent one 

 procured him only a very fniall cjuantity of filver. He again 

 calcined it, for three hours and a half, with i-joth muriate 

 of foda; and after thrue calcinations of the fimie kind under 

 the fame circumltances, and three alternate amalgamaiions, 

 bis mattes contained no more than i ounce and 18 deniers 

 of filver per quintal. 



C. Napionc obfcrves, that if his firft calcination bad been 

 carried further, he could have ex' rafted the whole of the 

 filver in three amalgamations. Having repeated, indeed, the 

 fame operation at the mint, employing the fame jiroportion 

 of fiilphur, he was able, after three fucccflive calcinations 

 and tluee amalgamations, to obtain a refiduum, which con- 

 tolned onlv an ounce and a half of filver per quintal. The 

 fiber cxtrafted on this occafion was of the quality of \\ de- 

 niers and 32 grains. It was of importance, after tills laft 

 trial, to undertake the experiments on a great fcale. 



On a hearth prepared with light brajcjue''', as for the re- 

 fining of common copper, and which C. Napione had |)laced 

 in a fituation where there was a current of air, a bafmi was 

 dug capable of containing about a quintal and a half of 

 picked matter : the chimney was difpofed in fuch a manner, 

 " A liiiiii^ or coating ot" 4 njixturc of c!;iy and pounduJ charcoal — 

 Eurr. 



that 



