specific Gravity, and comparative Wear of Gold. 
99 
Table I. 
Gold variously alloyed. 
Specific Gravity. 
car. grs. 
Gold, 23 fine, which had been rolled 
and stamped - - 
- - 19 , 277 . 
Gold, 23 3-§- fine, in the bar 
“ - 19 , 172 . 
oz. dts. grs. 
Gold, 23. 3j fine - - - 018101 
Platina* - - - 0 1 ip 
Gold, 23 3j- fine - - - 0 18 10I 
Platina - - - =-0114 
Copper - - 0 1 14 J 
- “ 19 , 013 . 
- - l6,8l6. 
Gold, 23 3! - - 0 18 10I 
Pure silver - - - 0 1 14J 
- - 1 7 > 9 2 7 - 
- - 17 . 344 - 
Gold, 23 3± - 0 18 10 'l 
Pure silver - - - 0 0 19 
Copper - - - -0019J 
Gold, 23 <3\ - - - 0 18 10 1 
Copper - - - 0 1 14 [ 
“ - 17 , 157 -t 
Gold, 23 3j - - 0 18 10 1 
Pure wrought iron - - 0 1 14 f 
~ " 16 , 885 + 
* The specific gravity of the platina was 18,717 ; and it has been already remarked, 
that it contained a small portion of iron. 
f The experiments upon gold made standard by silver, by silver and copper, and by 
copper alone, were made upon whole and complete ingots, which had been mixed and 
'cast with the greatest care, and which, separately, weighed two ounces Troy. 
$ If this metal had been cast in sand, it would have been porous, and the specific 
gravity would have been less than is stated in the table ; on this account, sand moulds 
were not employed in these experiments. 
The mould of iron, which has been so frequently mentioned, was not a common 
open ingot mould, but was a box of polished wrought iron, with a lid, which was 
ground so as to be air-tight. The mouth was at one end ; and a bar cast in this mould 
measured 12 inches in length, one inch in breadth, and £ of an inch in thickness. 
O 2 
