found in crude Platina. 42 1 
be wholly insoluble in nitro-muriatic acid, I judged it not to be 
platina. 
(A 4.) The c^stals also, instead of being nearly insoluble, 
like the ammoniaco-muriate of platina, were dissolved in a small 
quantity of water, and gave a rose-coloured solution. Upon 
mixing this with a solution of platina, the ammonia was trans- 
ferred by superior affinity to the latter, forming an ammoniaco- 
muriate of platina ; and the precipitate was of a yellow colour. 
Consequently, the metal contained in the salt, was neither 
platina nor that which gives the red colour to the salts of 
platina. 
It would be useless to detail my first unsuccessful experiments, 
made upon the properties of this metal, in hopes of discovering 
means by which its separation from platina might be effected ; 
I shall therefore confine myself to the following process, which 
appears to be the most direct for procuring rhodium in a state 
of purity. In the same process also palladium is obtained, so 
as to afford a presumption, that it is rather a natural simple 
body, than any artificial compound. 
(B 1.) Since the platina to be procured in this country, 
generally contains small scales of gold intermixed, as well as a 
portion of the mercury which the Spaniards employ for the 
separation of the gold, the platina used for my experiments, 
after being by mechanical means freed, as far as possible, 
from all visible impurities, was exposed to a red heat, for the 
purpose of expelling the mercury. It was then digested for 
some time in a small quantity of dilute nitro-muriatic acid, and 
frequently shaken, till the whole of the gold was dissolved, toge- 
ther with any impurities that might superficially adhere to the 
grains of platina. 
