292 CHEMICAL SCIENCE IN AUSTRALASIA. 
3. In amalgamation the pans and settlers consume not less 
than one and a half horse-power per ton of ore. The power for 
pumping solutions, &c., in the lixiviation process is merely 
nominal. 
4. In large mills the quantity of quicksilver in rotation repre- 
sents a capital of from £6000 to £8000, while the stock of 
chemicals required for lixiviation does not cost more than one- 
tenth of this amount. 
5. With Russell’s improvements, the percentage of silver 
extracted by lixiviation is much higher than by amalgamation. 
6. Lixiviation by Russell’s process requires a less careful 
chloridising roasting. In many cases the salt may be dispensed 
with. 
7. The value of the lost quicksilver and cost in wear and 
tear of the pans and settlers amounts to more than that of the 
chemicals consumed in the lixiviation process. 
8. The lixiviation process permits of the extraction of copper 
and lead as valuable by-products. 
9. The sulphides from the lixiviation process can be more 
easily converted into fine bars, and the gold parted, than this 
can be done with the bullion obtained in amalgamation. 
10. Amalgamation is invariably injurious to the labourer’s 
health. 
11. Where gold-bearing silver ores have been roasted with 
salt, lixiviation extracts, In most cases, more gold than amal- 
gamation. 
12. The possibility of lixiviating many so-called “free milling 
ores” without previous roasting, including tailings resulting from 
amalgamation of roasted or raw silver ores. 
13. The possibility of lixiviating with profit some classes of 
silver ores after they have been subjected to an oxidising 
roasting only. 
Since the foregoing was written, a patent by A. A. Lockwood 
and H. Chappel has come under our notice, in which the 
roasting of auriferous and argentiferous ores is performed in 
retorts by steam, super-heated steam, or carburetted hydrogen. 
An experimental plant has been erected in Sydney, but we 
have not yet had an opportunity of ascertaining the completeness 
of the operation. 
