and native Palladium from Brasil. 193 
by the tests of prussiate of mercury and green sulphate of 
iron, I was satisfied arose from palladium. The smaller frag- 
ment was then divided, and one portion allowed to remain in 
the acid till it seemed completely dissolved, and the other ex- 
amined by the blow-pipe. The utmost heat that could be 
given, appeared to have no effect ; but when a small piece of 
sulphur was applied to it, it fused instantly; by continuance 
of the heat, it parted with the sulphur, and became completely 
malleable. In short, it perfectly resembled palladium ; and 
as it retained its brilliancy in cooling, I judged it to be nearly 
pure. 
But as the surfaces which had been acted upon by nitric 
acid had a degree of blackness, that might be owing to some 
insoluble impurity, I have since that time dissolved the larger 
fragment forthe sake of discovering the cause of this appearance. 
Hot nitric acid dissolved by far the greatest part ; but there 
remained a black powder on which a fresh addition of this acid 
alone had no further effect. But when a drop or two of muria- 
tic acid was added, the whole was very soon dissolved. By the 
addition of muriate of ammonia, it became evident from the 
precipitate that the residuum was principally platina. But this 
precipitate, instead of being yellow, had the deep red colour, 
which is usually occasioned by the presence of iridium. The 
platina reduced from this precipitate was also too black for 
pure platina, and when it was again dissolved, the solution 
was of a deep red, and the precipitate by muriate of ammonia 
red, as before ; so that although the grains of Brasilian pla- 
tina appear to be free from iridium, as well as from many 
other impurities that form part of the Peruvian ore, yet the 
grains of native palladium that accompany them, afford a trace 
