C 316 3 
XXII, On the Discovery of Palladium ; with Observations on 
other Substances found with Platina . By. William Hyde 
Wollaston, M. D. Sec. R. S . 
rv 
Read July 4, 1805, 
Having some time since purified a large quantity of platina 
by precipitation, I have had an opportunity of observing various 
circumstances in the solution of this singular mineral, that have 
not been noticed by others, and which, I think, cannot fail to 
be interesting to this Society. 
As I have already given an account of one product obtained, 
from that ore, which I considered as a new metallic substance, and 
denominated Rhodium, I shall on the present occasion confine 
myself principally to those processes by which I originally 
detected, and subsequently obtained another metal, to which I 
gave the name of Palladium, from the planet that had been 
discovered nearly at the same time by Dr. Olbers. 
In the course of my inquiries I have also examined the many 
impurities that are usually mixed with the grains of platina, but 
I shall not think it necessary to describe minutely substances 
which have already been fully examined by others. 
§ I. Ore of Iridium . 
I must however notice one ore, that I find accompanies the 
ore of platina, but has passed unobserved from its great re- 
semblance to the grains of platina, and on that account is 
