On some Comlinations of Platina, 355 



the metal in its lowest siateof oxidation— as the black oxide 

 of platina. And the composition of this oxide, as deduced 

 from these experiments is in loo parts 



89-1 platina 



10'9 oxygene 



100-0 

 From experiments in the sequel on the potash sulphatai. 

 of platina, it appears that the black, oxide consists of 

 89*2 platina 

 10*8 oxygene 



100-0 



The coincidence between results obtained by such dif- 

 ferent modes, could not have been anticipated, and seem 

 to afford strong presumprions of their accuracy. 



In makinji; the preceding calculations, I have estimated 

 the weight o.- 100 cubical inches of oxygene gas at 34 grains. 



From a careful analysis o*^' some metallic sulphates, &c. 

 Professor Berzelius observed, that there seems to be a cer- 

 tain uniform ratio between the oxy5;ene in the base and in 

 the acid, and that the former is precisely half as much as 

 the latter ; and he conceives it probable that this rule may 

 generally obtain in the combinations of sulphur with other 

 combustible bodies. The sulphate of platina seems to 

 conform almost precisely to this rule. According to the 

 experiments of this distinguished chemist, 100 parts of 

 sulphuric acid contain 5942 of oxygene. Now 100 parts 

 of sulphate of platina appear to contain 73'7 of oxide of 

 platina at the minimum of oxidalio«, aud eO'.'J of acid. But 

 the 73*7 of oxide contain 8'OS of oxygene, and the 26 

 sulphuric acid contain 15-62 of oxygene. — The difference 

 here is extremely small, being only 0-19 per cent. 



The sulphate of platina appears to be an interesting 

 combination, and is distinguished from the other metallic 

 sulphates by very decided eharaclers. At present it is but 

 little known ; a more iutimaie acquaintance with it will 

 probably lead to the solution of a very interesting question ; 

 namely, whether oil of vitriol can exist in the fluid form 

 without the presence of water. 



7. Of some Triple Salts of Platina. 



The triple compounds obtained by the agency of the 

 volatile or fixed alkalies'on solutions of muriate of platina, 

 have been known for a considerable time : they are charac- 

 terized by containing muriatic acid, or rather I conceive 

 Z 2 chlorine, 



