specific Gravity , and comparative Wear of Gold. 73 
The grain of the fracture was fine, inclining to an earthy 
appearance, and was of a pale yellowish-gray colour. 
Experiment 111. 
Eighteen pennyweights and ten grains of fine gold, alloyed 
with 19 grains of copper, being melted, ng grains of fine grain 
tin were added, and, being properly mixed, the metal was poured 
into a cupel. 
The button was, externally, pale yellow ; and it soon broke 
under the hammer, with a close-grained and rather earthy 
fracture. 
Experiment iv. 
To eighteen pennyweights and ten grains of the fine gold, 
alloyed with one pennyweight and six grains of copper, in fusion, 
eight grains of pure tin were added, and treated as before. 
This metal resembled, in colour, gofd made standard by 
copper, excepting that it was rather paler ; it also proved to be 
perfectly ductile. 
Two pounds of gold were afterwards alloyed with tin and 
copper ; the former was in the proportion of eight grains in the 
ounce, similar to the last experiment ; and, in like manner, the 
alloyed metal was found to be perfectly ductile ; so that the bar, 
which at first was \ of an inch in thickness, was rolled as thin 
as a guinea, and, when thus rolled, it still remained so soft, that 
it was punched and stamped without being previously annealed.* 
* It has been suggested, that tin might be advantageously employed as an alloy for 
silver coin ; but, by some experiments which I purposely made, I found the fact to be 
the reverse ; for, when silver was alloyed with the standard proportion of tin, it proved 
brittle, and did not ring well ; and the same defects prevailed, when an alloy com- 
posed of equal parts of tin and copper was employed. 
L 
MDCCCIII. 
