240 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



Mean, 63.978, ± .0052 

 Hence Cd = 111.89. 



Combining this with the means found by previous experimenters, we 

 have for the percentage of oxide in oxalate — 



Lenssen 64.010, ± .0140 



Partridge 63.964, ± .0010 



Morse and Jones 64.003, ± .0042 



Bucher 63.978, ± .0052 



General mean 63.966, ± .0010 



Bucher's next series of determinations was b}' Partridge's method — the 

 conversion of cadmium oxalate into cadmium sulphide by heating in 

 a stream of sulphuretted hydrogen. The sulphide was finally cooled in 

 a current of dry nitrogen. The vacuum weights and ratios are subjoined : 



General mean, 71.974, ± .0007 



Here Bucher's mean practically vanishes. Taken alone, it gives Cd = 

 112.15. 



The third method employed by Bucher was that of weighing cadmium 

 chloride, dissolving in water, precipitating with silver nitrate, and weigh- 

 ing the silver chloride found. The cadmium chloride was prepared, partly 

 by solution of cadmium in hydrochloric acid, evaporation to dryness, and 

 sublimation in vacuo; and partly by the direct union of tbe metal with 

 chlorine. The silver chloride was weighed in a Gooch- crucible, with 

 platinum sponge in place of the asbestos. To the vacuum weights I 

 append the ratio 2AgCl : CdCL : : 100 : .r. 



