4*9 
found in crude Platina. 
acquainted with; and no experiment that I have made, has 
tended to confirm the suspicion of its being a compound, con- 
sisting of any known ingredients. The experiments above 
related, show evidently, that the ore of platina contains a very 
small quantity of palladium ; and it is not unlikely that this may 
have been a constituent part of some of the compounds obtained 
by Mr. Chenevix, and may have misled him, by some pro- 
perties which he would consequently observe, into the suppo- 
sition that he had formed palladium. 
It is not, however, without having repeatedly endeavoured to 
imitate his experiments, that I have ventured to dissent from 
such- authority. I made many attempts to unite pure platina 
with mercury, by solution, and by amalgamation ; but without 
success, in any one instance. 
From a solution of platina, carefully neutralized, as Mr. 
Chenevix directs, with red oxide of mercury, and mixed with 
a solution of green sulphate of iron, I indeed obtained such a 
precipitate of metallic flakes as he describes ; but, upon exami- 
nation of these flakes, they yielded mercury by distillation ; and 
the remainder consisted of platina combined with a portion of 
iron, but had not any properties which I could suppose owing 
to the presence of palladium. 
Upon comparing the specific gravity of this substance, which 
was said to be, at most, 1 1,8, with that of mercury or of platina, 
I was always strongly inclined to doubt the possibility of its 
being composed of these metals. I could recollect no ~one 
instance, in which the specific gravity of any compound is less 
than that of its lightest ingredient, and could not, without careful 
examination, admit the supposition, that mercury could be ren- 
dered lighter by intimate union with platina. It now appears 
