specific Gravity, and comparative Wear of Gold. 173 
Experiment 1. 
Table VIII. 
Number of revolutions, 11880. 
Quality. 
Weight be- 
fore friction. 
Weight after 
friction 
Loss. 
Gold 23 car. 3^ grs. unstamped 
Grains. 
284,20 
Grains. 
283,40 
Grains. 
0,80 
Gold 23 car. 3-I grs. stamped 
283,90 
280,10 
3.8a 
Gold made standard by silver, 
unstamped - - 
293 
292,30 
0,70 
Gold made standard by silver, 
stamped - 
289,70 
287 
2,70 
Gold made standard by silver 
and copper, unstamped - 
280,80 
280,50 
0,3° 
Gold made standard by silver 
and copper, stamped 
282,20 
280,40 
1,80 
Gold made standard by line 
copper, unstamped 
24 . 57 ° 
245 
0,70 
Gold made standard by line 
copper, stamped 
242,50 
240,60 
1 > 9 ° 
Gold made standard by equal 
parts of fine and dollar cop- 
per, unstamped 
245,3° 
245,10 
0,20 
Gold made standard by equal 
parts of fine and dollar cop- 
per, stamped 
248,90 
. 247,70 
1,20 
Gold of 18 carats,* unstamped 
209,70 
209,50 
0,20 
Gold of 18 carats, stamped - j 
207,30 | 
206,50 
0,80 
Standard silver, unstamped - j 
144,20 | 
1 43 ’ 2 ° 
1 
Standard silver, stamped - j 
14540 1 
143,60 
1,80 
Fine copper, unstamped - j 
15 1 ! 
150,80 
0,20 
Fine copper, stamped - - j 
154 >60 | 
-' 544 ° 
0,20 
# The gold of 18 carats employed in these experiments, was alloyed with copper; but 
I am well convinced that gold reduced to 1 8 carats by an alloy composed of silver and 
copper in different proportions, will be more easily worked than when copper alone forms 
the alloy, and will, in many respects, be found very useful by goldsmiths and jewel 
