62 Mr. Hatchett's Experiments on the various Alloys, 
From these and the following experiments it appears, that, of 
all those which have been improperly called semimetals, nickel is 
that which is the least injurious to the colour and ductility of 
gold. 
GOLD ALLOYED WITH MANGANESE. 
From what is at present known, it does not appear that this 
combination has till now been made. 
Experiment i. 
480 grains of gold, 23 car. 3^ grs. fine, being put into a 
crucible, were covered with about half an ounce of pure black 
oxide of manganese. The crucible was then exposed to a strong 
heat, in a wind furnace, during one hour and an half; but not 
any alteration was thus produced in the properties of the gold. 
Experiment 11. 
A quantity of olive-oil was several times mixed, and burned, 
with some of the oxide of manganese, after which, about one 
ounce of the oxide was put into a crucible lined with charcoal. 
A piece of fine gold, weighing one ounce, was then placed in 
the middle of the oxide, over which a stopper of charcoal was 
put, and the whole was closed by a cover, firmly luted. 
After a strong heat of one hour and an half, the crucible was 
removed, and, when cold, was broken. 
The manganese, in which the gold had been embedded, still 
remained in a pulverulent state, but, from black, was changed to 
a dark green. 
The button of gold at the bottom of the crucible was of a 
pale colour ; it soon broke under the hammer, and shewed a 
spongy coarse-grained fracture. 
