148 TRANSACTIONS OF THE CANADIAN INSTITUTE. [VOL. I. 



they are bound to sink as their surfaces are not to be compared with 

 their density and the water cannot resist them ; they will all either remain 

 in the battery or on the riffles as they are too heavy to be carried away 

 hydrodynamically. 



Then there is the great loss of mercury by neutralization by the arsenic 

 and sulphur, which I before mentioned, and also those ores the matrix of 

 which consists of calcium carbonate, cause enormous loss of mercury as 

 it is absorbed by the mercury and causes it to be spongy and light, and 

 to be carried away by the water more easily than even the fine gold itself. 

 Now the amalgamation process can be dispensed with in this treatment, 

 thus avoiding the above named loss. 



As regards the presence of lead or any other of the baser metals in the 

 ore to be treated, the lead would alloy and assist to collect the gold or 

 silver ; as to zinc, antimony or others they would be completely oxidised. 



In conclusion, I would lay special stress on the point that all ores 

 should be selected, and not as is at present done, all rushed through as 

 they come and by the same process, but arranged systematically and 

 treated accordingly. 



