48 Mr. Hatchett’s Experiments on the various Alloys , 
corroborated by the perfect ductility which the gold was found 
to possess. 
In this experiment, the whole of the arsenic was separated ; 
and we may conclude, that it is always difficult to combine 
arsenic with gold by mere addition in open vessels, and that 
when to a small quantity of gold in fusion, a small quantity of 
arsenic is added, it is immediately dissipated by the violence 
of the heat; but, if large quantities are employed, and the 
metal is poured as soon as possible after the addition of the 
arsenic, then, according to circumstances, a small portion may 
remain combined with the gold. 
It is well known that arsenic may be easily combined with 
gold and other metals, when in fusion, by employing a mixture 
of oxide of arsenic and black flux, and performing the opera- 
tion in close vessels ; but the following experiment will prove, 
that arsenic may at all times be combined with gold, provided 
the latter, when it loses its heat and congeals, is surrounded by 
arsenical vapour. 
Experiment in. 
480 grains of fine gold were put into a four-inch crucible, 
which was then placed within a large one that measured 
about 12 inches. At the bottom of this last, and on the outside 
of the small crucible, one ounce of metallic arsenic was placed, 
and another large crucible was then closely luted, with its 
mouth inverted upon that of the lower one. 
The whole was exposed to a strong heat in a wind-furnace, 
during two hours, after which, the vessels were suffered gra- 
dually to become cold. Upon removing the upper crucible, 
which formed the dome, some white oxide of arsenic was found 
adhering to the inverted bottom of it. 
