308 PROCEEDINGS OF SECTION B. 
exhausted. Up to this point the defects of the Russell process 
are the defects of amalgamation also; and if the Russell process 
has failed to extend, so has the amalgamation process, and for the 
same reasons. Both fail to extract anything but gold and silver, 
and both require a generally expensive chloridizing roasting, which 
causes a loss of silver amounting to at least 8 per cent. of the total 
contents, which loss by unskilful work is Jargely increased. This 
heavy preliminary loss far exceeds the total loss at a good smelter, 
and alone is a heavy handicap. At amalgamation mills this loss 
was formerly neglected or denied altogether, and it seems impos- 
sible to lessen it materially. From this point onward the advan- 
tages are all on the side of the Russell process, especially since the 
refining of the sulphide precipitates by the Dewey process has been 
so successful. Had the conditions remained favourable to the 
extension of amalgamation, it is safe to assume that Russell’s 
process would have fulfilled the early hopes of its supporters ; but 
the improvements in smelting, and the increased cheapness of 
transit to large smelters where ores of all kinds make self-fluxing 
mixtures, have lowered smelting charges to a point which leaves 
small opening for other processes. The Russell process, like most 
others, cannot compete with smelting at equal prices. 
In places where siliceous silver ores carrying no other metal of 
value occur far from railroad facilities, the Russell process will 
still hold its own, and its results can be calculated with certainty 
beforehand. Compared with the older lixiviation processes, Russell’s 
is in the direction of greater efficiency, and the adoption of his 
improvements is simply a question of relative economy. The great 
fall in the price of silver lessens the value of his extra solution, but 
the ore must be indeed of low grade when its use costs more than 
its return. Where the ores to be treated contain blende, even in 
small quantities, and the roasting is done in mechanical furnaces, 
the use of the extra solution becomes imperative, owing to the 
reducing action of the unaltered zinc sulphide on the chloride of 
silver formed in roasting, as soon as leaching begins. 
The history of the process in Australia is short. 
Mr. T. G. Davey, then metallurgist at the Boorook Silver-mines, 
was the first to experiment with the process in this country. 
At an early date that gentleman did some large-scale experiments 
upon ore obtained from the newly discovered Webb’s Silver-mine, 
near Emmaville, and as a result of those experiments, and upon 
his recommendation, a plant was erected there to use the process. 
Mr. Davey directed operations at first, but was superseded by 
gentlemen from America, who were supposed to have special know- 
ledge of lixiviation. None of these gentlemen carried the process 
to a successful issue financially, and ultimately the plant was dis- 
mantled and sold. Mr. Davey states that the process was a success 
from a metallurgical point of view, an extraction of 90 per cent. 
