210 Value of Native Gold, cc. 
This result is easily explained, for it is evident that the 
lighter the material combined with the Gold, the less amount 
will be required to reduce its specific gravity, and, therefore, 
that the compound will contain more of the most valuable 
metal, and less of the inferior. 
Silver, with the exception of platina, is the heaviest of the 
metals usually found in combination with Gold; and as the 
value of platina is equal, if not superior, to that of Gold, 
it is not of importance, in a mercantile point of view, to 
attempt to determine a matter which can have little or 
no effect upon the market price of the commodity. I have 
therefore assumed that Silver is the alloy generally found 
with the native Gold both of California and these Colonies. 
Tt is known to be the case as regards California; and in 
taking it for granted here, any calculations which I may 
make will err in defect rather than in excess. 
The following experiments were made for the purpose of 
determining the specific gravity of different specimens of 
Gold completely free from extraneous matters :— 
5. A specimen of Californian Gold, apparently crystallized, 
Grains. 
Weighed in air ...cccccossessesseere §28°D 
Weighed in water eeeereoeeeseeegere 26'85 
Difference ....ccccccsesescse 1°65 
28°5_ ¥ 1000 = 17272 Sp. Gr. 
1:65 
6. Aspecimen of Californian Gold containing a quantity of Quartz, 
Grains. 
Weighed in air w.sscssscsecceeese 279°87 
Weighed in water .....ssesceere 260°25 
Difference .recccccocscees 19°62 
279°87 ts 
