684 PLATINUM. 



by the usual reagents. When a hot saturated solution of this 

 salt is mixed with sulphate of soda, a corresponding sulphate 

 of less solubility is deposited in small needles. A hydro- 

 chlorate is also obtained by adding hydrochloric acid to a 

 boiling solution of the nitrate or sulphate, which crystallizes on 

 cooling in octohedral crystals. By mixing a solution of the 

 nitrate with a soluble oxalate, phosphate, tartrate, citrate, 

 malate and saccharate, compounds of these acids with the same 

 base were produced, which are all crystallizable and less soluble 

 in the cold than the nitrate.* 



These salts are represented as containing a substance Pt, 

 Cl N 2 H 6 , of the same character as ammonium : 



Hydrochlorate , . . Pt, Cl N 2 H 6 +C1. 



Nitrate Pt, Cl N 2 H 6 O + NO 5 . 



Sulphate ..... Pt, Cl N 2 H 6 O + SO 3 . 



Oxalate Pt, Cl N 2 H 6 O + C 2 O 3 . 



M. Liebig also suggests another view, that these salts con- 

 tain a salt of platinum, analogous to the bichloride, but in 

 which the second atom of chlorine is replaced by amidogen, that 

 isPt + Cl.NH 2 . This salt is combined with chloride of 

 ammonium, in the hydrochlorate ; which thus becomes anala- 

 gous to the bichloride of platinum and potassium, of which 

 the new salt has the form. The nitrate, sulphate, and oxalate 

 are compounds of nitrate, sulphate and oxalate of ammonia 

 with the same salt Pt + Cl.NH 2 . This last view, which is so 

 simple, is opposed by the fact that neither chlorine nor platinum 

 is precipitated from these salts by the usual reagents. But this, 

 I think, is not a sufficient ground for its rejection, considering 

 how little many admitted double salts are affected by the 

 reagents which precipitate the salts individually before their 

 combination, such, for instance, as the double oxalate of 

 chromium and potash. 



Corresponding platinous iodides and cyanides have been 

 formed. The platinous oxide has also been united with several 

 acids, particularly sulphuric, nitric, oxalic and acetic acids ; but 

 none of these salts has been crystallized, except the oxalate. 



Peroxide of platinum, Platinic oxide, Pt O 2 , 1433.5 or 114.84. 

 By precipitating sulphate of platinum with nitrate of 



* Gros, An. de Ch. et de Ph. t, 69, p. 204. 



