AND OTHER METALS FROM PYRITES. 95 
ntage oe assay may ex r cent.; even when the metal- 
lurgic method is quite perfect i t as por a met 
far from , the difference is still 
m 
of no p 
only give an outline of the a aed ado opted with a few results 
ected from i 
erous ex 
e quantity of material o ested on in all cases was 3,667 
—_ from which quantity Poniap reece grain represents re oz. per 
"The first process which suggested itself for the extraction of 
gold was to take advantage of the solubility of sulphide of gold 
in solutions of alkaline sulphide, for if this ay be effected it 
would render the roasting of the ores unnece 
In 1859, Henderson included in his ange foe the extraction 
of copper, a process for extracting gol phide. His - 
tions are that the pyrites be fused to pr srt a matt which is to 
be fused with two parts of salt cake (crude sulphate of sodium), 
and the matt run into pigs. These. placed in water crumble to 
ieces ; and the gold is obtained in solution, whence it may be 
recov ered by precipitation with an acid. 
, ® process was patented in America for the extraction 
of mold. by “ sulphur and its wales: - wat of this I have no details. 
The _ rst experiments were made by treating portions of each 
ore with solution of sulphide of sodium containing a slight 
excess of sulphur. The ex eriments were varied in. ‘concentra- 
bs 
regulus here et in atrah as descri im, bs 
two trials, obtain any fer in ogenerg sl i 
modified, with oe eS a Blige: 
sulphide of sodium npr with ats 7; ie Mi ie 
by Satie finely powdered ore to a dull red 
= 
by Price, who, in January, 1857, patented i ica 
for the extraction of gold from its ores by fusing them with 
sulphide and lus with aqueous chlorine 
* Rivot Ann. Min. [6] vu. 1. Watt's Dict. Chem., Second Supplement, p. 572. 
* 
