68 Mr. Hatchett's Experiments on the various Alloys , 
The following experiments were made, to ascertain the effects 
of the fumes or vapour of bismuth upon gold, when melted in 
close, and when in open vessels. 
Experiment vii. 
One ounce of the fine gold, being put into a small four-inch 
crucible, was placed within a large one of about 12 inches, and 
another large crucible, inverted, was then fixed and luted, in the 
manner of a dome. One ounce of bismuth was previously put 
into the inferior large crucible, on the outside of that which 
contained the gold, after which, a strong heat was kept up 
during two hours. 
Upon opening the vessels, the bismuth was found in a mass, 
at the bottom of the large crucible ; but a considerable part had 
been volatilized ; for the button of gold, which before the ex- 
periment weighed 480 grains, now weighed 51 2,2 grs. and had 
therefore acquired 32,2 grs. of bismuth. It was, externally, of 
a pale brassy colour, and immediately split under the hammer, 
with a coarse-grained fracture. 
Experiment vm. 
The preceding experiment was repeated, but without the 
upper large crucible or dome, so that a free circulation of air 
was admitted. When half an hour had elapsed, the crucible 
containing the gold was removed. 
The external colour of the button was not altered; but it 
proved to be so brittle, that it was immediately broken by the 
first blow of the hammer. 
The whole of the foregoing experiments concur to prove, that 
bismuth, under all circumstances, readily combines with gold, 
and that it is most exceedingly injurious to the ductility of it. 
