CF{o,x™^;rT.4x+2PtCP. 



258 Mr. F. Claudet on a Class of 



the formula of which is — 



NH^Co* 



2(NH8NH'*) 



When this salt is decomposed by heat, treated with nitro- 

 hydrochloric acid, and the excess of acid driven off by heat, the 

 solution crystallizes in large orange-brown prismatic tables, no 

 mother-liquor remaining. This salt proves to be a double chlo- 

 ride of platinum and cobalt, the 2 equivalents of bichloride of 

 platinum combining with 2 equivalents of protochloridc of cobalt 

 from the new compound. 



Double salt with bichloride of mercury.- — Prepared in the 

 same way as the preceding double salt, by adding a waim solu- 

 tion of the cobalt salt to an excess of bichloride of mercury, a 

 bulky silky precipitate is formed composed of small red needles. 

 This may be collected on a filter, slightly washed with cold water 

 and recrystallized from a warm solution, this double salt being 

 tolerably soluble in hot water. 



15 grains fused with carbonate of soda in the same way as the 

 double platinum salt, gave 18'10 grs. Ag CI = 4*477 CI = 29-84 

 per cent. 



14*16 grs. reduced by hydrogen gave 0*80 cobalt =5*65 per 



cent. 



Calculated. 



Found. 



9C1 =319*5 30*00 2984 

 6Hg=600 



2Co = 59 5-54 5*65 



5N = 70 

 16H = 16 



This double salt contains, therefore, for 1 equivalent of the co- 

 balt compound, 6 equivalents of bichloride of mercury. 



CH?(NH%H^) + 6"«C'- 



Recently prepared oxide of silver throws do^n the chlorine 

 from the new ammoniacal compound, a highly alkaline red solu- 

 tion remaining, not having the slightest odom* of ammonia. On 

 standing a few hours it decomposes, ammonia is evolved, and 

 hydratcd peroxide of cobalt precipitated. The compound in so- 

 lution represents before changing, the base of the present class 

 of salts. It is an oxide, of which the composition is the same as 

 that of the chloride already described, with the substitution of 

 3 equivalents of oxygen for 3 equivalents of chlorine : — 



fNH^Co^ 

 Formula of new cobalt base .... 0^-^ NH^NH*. 



