Ammoniacal Compounds of Cobalt. 255 



moisture is ppduced, which would necessarily be formed if any 

 oxygen existed in the compound. 



The analysis of this salt was effected in the following manner. 

 The chlorine was estimated from the chloride of silver, obtained 

 on boiling the solution with an excess of nitrate of silver and 

 nitric acid. In the cold the precipitation by nitrate of silver is 

 not complete. The cobalt was determined by reducing a certain 

 quantity of the substance introduced into a tube with a bulb, by 

 pure hydrogen and heat. The nitrogen was estimated as am- 

 monia, by distilling the salt with caustic soda, receiving the 

 ammonia into hydrochloric acid, and determining the weight of 

 the double chloride of platinum and ammonium. The ammonia 

 was also obtained by heating the salt with soda-lime, according 

 to the method of Will and Varrentrapp. This last process, how- 

 ever, gave less accurate results, a deficiency of about 1 per cent. 

 in the nitrogen being found. The hydrogen was determined by 

 combustion of the salt with a mixture of oxide of copper and 

 chromate of lead, and copper turnings. 



The following are some of the results obtained : — 



Per cent. 

 20 grains of salt gave 34-14 Ag CI =8-445 CI 



12 

 10 

 19 



8-68 



9-48 

 12-51 

 14-81 



8 

 13 

 13-5 

 11-655 



The number of equivalents of chlorine, cobalt, nitrogen and 

 hydrogen deduced from these results, are 3C1, 2Co, 5N and 16H, 

 as may be seen from the calculated numbers : — 



Found. 



,251-5 10000 > 



The salt containing a large quantity of chlorine, it might be 



expected that the volatilization of minute quantities of chloride 



of copper or chloride of lead in the combustion would give an in- 



crease in the results for the hydi-ogen, one equivalent of the latter 



T2 



