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XXX. On a new Metal, found in crude Platina. Bi/ 

 William Hyde Wollaston, M. D. F. R. S.* 



OTWiTHSTANDiNG I was fiware that M. Descotils had 

 ascribed tiic red colour oi" certain precipitates and salts qf 

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

 Tennant had Qiiliglngly communicated to nie his discovery 

 of the same substance, as well ^is of a second new metal, in 

 the shining powder that remains undissolved from the ore of 

 platina; yet I was led to suppose that the more soluble parts 

 of this mineral might be deserving of further examination, 

 as the fluid which remains after the precipitation of platma 

 by sal ammoniac, presents appearances which I covdd nqt 

 ascribe to either of those bodies, or to any other know;i 

 substance. 



My inquiries having terminated more successfully than I 

 had expected, I design in the present Memoir to prove the 

 existence, and to examine the properties, of another metal, 

 hithcirto unknown, which may not improperly be distin- 

 guished by the name of rhndhim, from the rose-colour of a 

 dilute solution of the salts containing it. 



I shall also take the same opportuuity qf staling the result 

 of various experiments, which have convinced me, that the 

 metallic substance which was last year offered for sale bv 

 the name of palladium, is contained (though in very small 

 proportion) in the ore of platina. 



The c(.'!our of the solution that remains after the precipi- 

 tation of platina, varies, not only according to its state qf 

 dilution, biit also, according to the strength and proportions 

 of the nitric and muriatic acids employed. This colour, 

 though principally owing to the quantity of iron contained 

 in it, arises also in part from a small quantity of the am- 

 ?Boniaco-m,uriate of platina, that necessarilv remauis dis- 

 solved, and from other metals coutuined in still smaller pro- 

 portions. 



(A 1.) To recover the rcmaiaii"\g platina, as well as tip 

 separate th? other metals that are present from the iron, I 

 have in some experiments employed zinc, iii others iron, for 

 their precipitation. The former appears preferable; but, 

 when the latter has been used, the precipitate may imme- 

 diately be freed fronj the iron that adiieres to it, by muriatic 

 acid, without the lo^s of any of those metals which are at 

 present the SI bject of inquiry. 



* From tlie T,uinuitiO'is of thi linxal Hjcieiy of Lomhr for \%c:x. 



