4 6 Mr, Hatchett's Experiments on the various Alloys , 
same time, I wish it to be understood, that I alone am to be 
considered as responsible for any inaccuracies of the experi- 
ments. 
Lastly, before I proceed, I must take this opportunity to 
acknowledge my obligations to James Morrison, Esq. the 
Deputy Master of the Mint, to Mr. James Morrison, his son, 
to Robert Bingley, Esq. his Majesty's Assay Master, and to 
Messrs. ATKiNsoNandNicHOLL,of the Corporation of Moneyers, 
for the ready assistance and polite attention which I received 
from those gentlemen, during the long series of experiments 
made at the Mint, 
SECTION I. 
ON THE VARIOUS ALLOYS OF GOLD. 
The wear of coin is an effect produced by mechanical causes, 
subject to be modified by certain physical properties, such as 
ductility and hardness, which vary in degree, according to the 
chemical effects produced by different metallic substances, when 
employed in certain proportions as alloys. From these consi- 
derations, it appears proper, 
First, to examine the effects which the various metals produce 
upon gold, when combined with it in given proportions, begin- 
ning with Aj, which is the standard proportion of alloy, and in 
certain cases gradually decreasing to £ of a grain in the ounce 
Troy, or T ~ part of the mass. 
Secondly, to examine the specific gravity of gold differently 
alloyed, and the causes of certain variations to which it is liable. 
And, thirdly, to ascertain the effects of friction variously 
modified. 
