NEW METAL FOUND IN CRUDE PLATINA. <]Ck 



when one part of rhodium had been fufed with three parts of 

 bifmuth, of copper, or of lead, each of thefe alloys could be 

 diflblved completely, in a mixture of two parts, by meafure^ 

 of muriatic acid, with one of nitric. With the two former 

 metals, the proportion of the acids to each other feemed not to 

 be of fo much confequence as with lead; but the lead appeared 

 on another account preferable, as it was molt eafily feparated, 

 when reduced to an infoluble muriate by evaporation. The 

 muriate of rhodium had then the fame colour and properties, 

 as when formed from the yellow oxide precipitated from the 

 original fait. (D 1.) 



(E 8.) The fpecific gravity of rhodium, as far as could be Specific gravity. 

 afcertained by trial on (o fmall quantities, feemed to exceed 1 1 . 

 That of an alloy confiding of one part rhodium and about two 

 parts lead, was 1 1,3; which is fo nearly that of lead itfelf, that 

 each part of this compound may be confidered as having about 

 the fame fpecific gravity. 



F. As it was expected that the alcohol employed for wafhing The alcohol 



the fait of rhodium (B 6.) would contain the foda-muriates of bef ° re ufe u d «?. 



x . ' . . wafhing the lalts 



platina and of palladium, the platina was firlt precipitated by examined. 



fal ammoniac. This precipitate was of a deep red colour; and, 

 when it had been heated, to expel the fal ammoniac, the pla- 

 tina which remained was of a dark gray colour. 



(G 1.) To the remaining folution, after it had been diluted 

 to prevent any further precipitation of platina, I added pruf- 

 fiate of potafii, which inftantly occafioned a very copious preci- 

 pitate, of a deep orange-colour at firft, but changing afterwards 

 to a dirty bottle-green, which I afcribed to iron contained in 

 the prufliate. 



(G 2.) This precipitate, when dry, weighed 12f grains, 

 After it had been heated, it left a metallic refiduum, in fmall 

 grains, of a gray colour, weighing nearly 7 grains. A fmall 

 portion of it being heated with borax, communicated a dark 

 brown colour to the borax, as from iron, and acquired a bright 

 metallic luftre, but could not be fufed under the blowpipe. 

 With fulphur, however, it fufed immediately into a round 

 globule, which, by floating upon mercury, appeared of lefs 

 fpecific gravity than that metal. 



(G 3.) The whole quantity was then treated in the fame 

 manner, and purified by cupellation with borax, till it cooled 

 with a bright furface. From the globule the fulphur was ex- 

 pelled, 



