J22 ^^ PLATINA. 



The red preci- If the red precipitate be reduced, the metal obtained is of 

 pitate affords a ^ different nature from the former. It is far more infoluble in 

 Jefs foluble metal . •••..,, ,-. r -j i. 



which leavL-s a nitro-niuriatic acid, and whatever quantity of acid may be 

 b'ack powder, applied, there remains conflantly a quantity of black powder, 

 Mecip."'^ ^ " which is abfolutely infoluble in the acid. This folution, on be- 

 ing decompofed by muriate of ammonia, yields a red precipi- 

 tate. 

 This precipitate To learn the nature of this precipitate, I reduced a quan- 

 nniled'^mwi'a'te^'^y °^ ^^» introduced it into a JDorcelain tube, connefled with 

 ofpotafliwith a fmall retort, containing hyper-oxiginized muriate of potafh, 

 **^*'^* and applied heat to the retort, after having firft adapted to the 



other extremity of a receiver containing a little water. On in- 

 creafing the heat fo as to decompofe the hyper-oxiginized mu- 

 Blue powder riate, the tube became lined with a blue powder, which was 

 ©bteined j ^[^q obferved in the empty part of the receiver. 



After all the fait in the retort had been decompofed, I col- 

 lected the blue fubiimed powder. The minute quantity of it 

 however did not permit me to fubmit it to many experiments, 

 —foluble in It was eafily foluble in nitro-muriatic acid. Its nature will 

 nitro.muriatic ^g^^^g ^^^e obvious hereafter, 

 acid. 

 The red colour From what has been fo far fiated, it appears to follow that 



the red colour of the triple precipitate of platina, obtained by 

 muriate of ammonia, or other falts with alkaline bafes, is ow- 

 ing to the prefence of a peculiar metal contained in the pla- 

 tina, which has hitherto been confidered as fimple. 



Examination of the triple Muriate of Platina and Soda. 

 Triple muriate This triple compound is very little known.* It may eafily 

 of platina and be obtained by pouring into a folution of platina, a fait with 

 bafc G^ foda. It is very foluble in water, and even in alcohol. 

 The folutions are capable of cryftallizing in long prifms, on 

 three-fided tables, of a yellowith red colour. It is decom- 

 pofable by muriate of ammonia; the precipitate is a muriate 

 of platina and ammonia. It is likewife decompofed by a fo- 

 lution of foda; on adding this alcaii in excefs, the formed pre- 

 cipitate becomes again diffolved. 

 Reducible on Muriate of platina and foda is reducible upon charcoal be- 



bbw°i''e?^ ^' ^^""^ *''^ blow-pipe. The reduced metal poffefTed a confider- 

 able luftre. 



* Mufllii-Pufchkin has pointed out fome of its properties in 

 Crell's Annales, 1800, Vol. I. p. 93. of which a thort abttraft is to 

 be found in the Annales de Chimie. p, 277. 



2 If 



aiifes from a 

 peculiar metal 



