34 S£ w METAL FOUND IN CRUDE PLATINA. 



X. 



On a new Metal, found in Crude Platina. By William Hyde 

 Wollaston, M. D. F. R.S. From the PhilofophicalTranf- 

 actions, 1804. 



Introduction. NOTWITHSTANDING I was aware that M. Defcotils 

 had afcribed the red colour of certain precipitates and falts of 

 platina, to the prefence of a new metal; and although Mr. 

 Tennant had obligingly communicated to me his difcovery of 

 the fame fubftance, as well as of a fecond new metal, in the 

 fliining powder that remains undilfolved from the ore of platina ; 

 yet I was led to fuppofe that the more foluble parts of this mi- 

 neral might be deferving of further examination, as the fluid 

 which remains after the precipitation of platina by fal ammo- 

 niac, prefents appearances which I could not afcribe to either 

 of thofe bodies, or to any other known fubftance. 

 New mttal, My inquiries having terminated more fuccefsfully than I had 



Kbidium. expected, I defign in the prefent Memoir to prove the exiftence, 



and to examine the properties, of another metal, hitherto un- 

 known, which may not improperly be diftinguifhed by the name 

 of Rhodium, from the rofe-colour of a dilute folution of the 

 falts containing it. 

 Palladium found I fliall alio take the fame opportunity of ftating the refult of 

 inoreof platina. various experiments, which have convinced me, that the me- 

 tallic fubftance which was laft year offered for fale by the name 

 of Palladium, is contained (though in very final 1 proportion) 

 in the ore of platina. 

 Remaining h- The colour of the folution that remains after the precipitation 

 latum after pre- f platina, varies, not only according to its ftate of dilution, but 

 tina contains* a ^° accor ding to the ftrength and proportions of the nitric and 

 iron and other muriatic acids employed. This colour, though principally 

 owing to the quantity of iron contained in it, arifesalfo in part 

 from a fmall quantity of the ammoniaco-muriate of platina, that 

 necefiarily remains diflblved, and from other metals contained 

 in ftill fmaller proportions. 

 Precipitabk by (A. 1.) To recover the remaining platina, as well as to fe- 

 zinc or iron. parate the other metals that are prefent from the iron, I have 

 in fome experiments employed zinc, in others iron, for their 

 precipitation. The former appears preferable; but, when the 

 latter has been ufed, the precipitate may immediately be freed 



from 



