XXXVII. Experiments on mixing Gold with Tin. In a Letter 
from Mr. Stanefby Alchorne, of bis Majefty’s Mint, to Peter 
Woulte, Hyg. F. R. 8. 
Read June 24, 1784. 
| Seed eae eee 
OU know it 1s a generally received opinion among me- 
tallurgifts,. that tin has a property of deftroying the duc- 
tility of gold, on being melted with it, even in very fmall 
quantities. Our late ingenious countryman Dr. Lewis, in his 
Philofophical Commerce of Arts, p. 85. has. well expreffed 
the fenfe of moft writers on this. fubjeét, in the following 
words: ‘* The moft minute proportion of tin and lead,” fays. 
he, ‘“‘ and even the vapours which rife fromthem im the fire, 
<¢ though not fufficient to.add to the gold any weight fenfible 
‘< in the tendereft balance, make it fo brittle that it flies in. 
«6 pieces under the hammer.” 
Divers circumftances, neverthelefs, long fince induced me 
to difbelieve the fa&t; but thefe, having chiefly arifen from 
{mall experiments, did not feem to warrant any general con- 
clufion. A late public occafion, however, which led me to. 
various trials of mixing thefe metals together, in different pro- 
portions, and in. ie eee large quantities, has put the matter 
out of difpute;, and fhewn me, that tin, in {mall quantity at 
leaft, may be added to gold, either pure or alloyed, without 
producing any other effeét than what might eafily be con- 
ceived, 
