CADMIUM. 



163 



of cadmium. Their mean, taken in one series, has really no significance ; 

 but as the computations in this work involve a study of compensation 

 of errors, the data may be combined with their predecessors, as follows : 



Morse and Jones 87.5066, .00032 



Lorimer and Smith 87.5044, rh .0023 



Bucher 87.495, .0035 



General mean 87.5064, db .0003 



This is equivalent to the absolute rejection of Buchers data, and is 

 therefore not wholly fair to them. His work throws doubt upon the 

 validity of the ratio, as determined, altogether. 



The latest determinations relative to the atomic weight of cadmium 

 are those of Hardin.,* who effected the electrolysis of the chloride and 

 bromide, and also made a direct comparison between cadmium and 

 silver. The aqueous solutions of the salts, mixed with potassium 

 cyanide, were electrolyzed in platinum dishes. The cadmium which 

 served as the starting point for the investigation was purified by distil- 

 lation in hydrogen. All weights are reduced to a vacuum. The data 

 for the chloride series are as follows, with a column added for the per- 

 centage of Cd in CdCl a : 



Weight CdCl v 



.43 HO 



.49165 



.71752 



.72188 



.77264 



.81224 



.90022 

 1.02072 

 1.26322 

 L52344 



Weight Cd. 



.26422 

 .30112 

 43942 

 .44208 



.49742 



.55135 

 .62505 



.77365 

 933*4 



Percentage Cd. 

 61.247 

 61.247 

 61.241 

 61.241 

 61.245 

 61.240 

 61.246 

 61.236 

 61.244 

 61.252 



Mean, 61.244, .0010. 



The results for the bromide, similarly stated, are these: 



' Journ. Amer. Gheni. Soc., 18, 1016. 1896. 



