18 PROCEEDINOS OP THE AMERICAN ACADEMY 



Tlie formula Co,(Nig,oCl„+3rtCl,+80H2 requires: — 



Calculated. Found. 



Col.alt. 7-08 7-07 



riutinum, 35-56 35-45 



Chlorine, 38 3G 38-50 



Tliese analyses were not publislied in the first part of this paper, be- 

 cause Genth and I did not succeed in preparing the salt a second time. 

 ] do not myself consider them — in spite of their close agreement with 

 the fonimla i:i\iMi — sufl^icient to establish the existence of the salt in 

 question. P\irther researches may be mors successful in this respect. 

 Sulphato-cJthrpIatlnate. — When chlorplatinate of sodium is added 

 to a solution of the soluble sulphate of roseocobalt, a beautiful bright- 

 red crystalline salt is precipitated, which is but slightly soluble in cold 

 water, but which may be dissolved in a very large excess of boiling 

 water with a few drops of free acid, and crystallizes from the solu- 

 tion without decomposition. This salt has the formula, — 



Co,(NH3),„(SO,),Cl,+PtCl„ 



as the following analvses show : — 



0-4806 gr. gave 0-3476 gr. silver = 23-78^ chlorine. 



0-4221 gr. gave 0-1505 gr. platinum and cobalt = 35-65 p^. 



0-M2« gr. of the mixed metals gave 0-0898 gr. platinum = 22-43% 



(of the salt), and 13-22i^ cobalt (by ditference). 

 0-5210 gr. gave 0-2618 gr. SO.Ba = 20-66r/^SO,. Salt fused with 



The formula re- 



A solution of the yellow modification of the sulphate of roseocobalt 

 already dt^scribcd, gave with chlor])latinate of sodium a beautiful yel- 

 low crystalline precipitate remarkably insoluble even in hot water. 

 This salt, after washing and drying in pleno over sulphuric acid, was 

 analyzed : — 



0-4202 gr. gave 01488 gr. i)latmum and cobalt = 35-415^. 



