sil ON A METHOD OF EXTRACTING GOLD, SILVER, 
solution of sulphate of copper from the coolers, which is made 
boiling hot in a leaden or copper boiler, until the specific gravity 
of the ovine 3 and escaping solutions is the same. ole 
iquors are run into wooden ouelens where coven 
d. n t 
or so above the solid contents, and 12 inches of water are © 
dourtinaisd from below until the water is only an inch above the 
solid contents, when a s d wash is run on, and in the same 
manner a third = necessary. The copper liquors are run to the 
coolers as long as they mark above 20° of Twaddel, below that 
strength diag are to aseparate tank to be used for the first 
wash of another 
Ifthe ore contains phen, a little is found in solution in the 
of copper, before oe rs eg lag to the coolers. The silver 
is recovered from time to time by roastin a the precipitate, ex- 
ver. 
‘The residue in the lixiviating tanks is drained, dried, mixed 
with one-fourth of its weight of carbon, reduced, and oblierwins 
treated as above described, to obtain ‘the gold and remaining 
silver. 
The re eae of sulphates of copper and iron in the coolers are 
removed from time to time, drained and dried. One ton of the 
“od : 
c s is charged into the muffle fu fig. 2, B, and 
the posed to a full cherry-red heat, so as to convert the 
whole of the sulphates into oxides e urous and 
e acids are condensed, and used for extracting roasted ore. 
When vapours are no longer evolved the calcined residue is 
removed from the muffle. A similar charge of dried sulphate is 
heated in the muffle furnace at c to a dull-red, so as to convert 
the sulphate of iron into. Hew and when fumes are no longer 
evolved the Se ead is raked out, mixed with 2} ewt. of coal or 
charcoal dust — =< into the reverberatory furnace, A, 
7 
ucting the copper by Seatnass liquor, and melting the residual 
