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XXII. On the Discovery of Palladium; with Observations on other Substances found with Platina. By William Hyde Wollaston, M.D. Sec. R.S.
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 resemblance to the grains of platina, and on that account is