Value of Native Gold, ce. 217 
extensive to embrace all the average specimens, and which 
can easily be carried lower if necessary :— 
Specific Weight Quantity Quantity of 
Gravity of f Extraneous 
0 (0) 
Sample. | Sample. Gold. Matter. 
18000 | 480 478°66 
17000 473°87 
16000 468°48 
15000 46237 
14000 455°39 
13000 447°34 
12000 437°93 
11000 426°82 
10000 413°49 
9000 397:20 
8000 376 83 
7000 350°65 
‘This Table needs but little explanation: the value of 
the Gold is’ deduced from that given in the former Table 
opposite the specific gravity 18300, which is here taken as 
the point of commencement. It will be seen on inspection, 
that a large decrease in the specific gravity of a sample 
does not produce a corresponding diminution in its value ; 
for instance, a decrease in the specific gravity from 18300 to 
12000, or upwards of 33 per cent., only takes off about 10 
per cent. of the value. 
The following experiments will show the extent to which 
the Table may be trusted in determining the quantity of 
Gold in any mixed specimen :— 
Grains. 
21. Weight of specimen in air.........ssssssssescosedersers 1375 
Nets amywaterdl-scal<ccasscsvcsconss ezedeccausaass esi L27O'FO 
Difference ..cccccosccecescsoere 98°25 
1375 
08-25 * 1000 = 13994:'9 Sp. Gr. 
By referring to the Table it will be seen that a specimen 
whose specific gravity is 14000 contains 24°61 grains of 
ae 
