CADMIUM. 



161 



Bucher's next series of determinations was by 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 sub- 

 joined : 



Oxalate. Sulphide. Percentage. 



2.56319 1.84716 72.065 



2.18364 I-5734I 72.055 



2.11643 1.52462 72.037 



3.13105 2.25582 72.047 



Mean, 72.051, =b .0127 

 Partridge found, 71.973, .0007 



General mean, 71.974, .0007 



Here Bucher's mean practically vanishes. 



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 

 the 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 2 : : 100 : x. 



3.09183 

 2.26100 



1-35729 



2.05582 



1.89774 



3-53 6 7 



2.70292 



4.24276 



3.40200 



4.60659 



2.40832 



2.19144 



2.84628 



2.56748 



2.31003 



.25008 



.96015 



.29787 



.94227 



.10976 



.63080 



AgCl. 



4.83856 



3.53854 

 2.12431 

 3.21727 

 2.97041 



5.48473 

 4.23087 

 6.63598 



5-3 2 3 r 4 

 7.20386 



3.42724 



4-45477 

 4.01651 

 3.61370 

 1.95652 

 3- 6 54i 

 3-59391 

 3.03811 



1.73547 

 2.55016 



Ratio. 

 63.900 

 63.896 



63-893 

 63.899 

 63.886 

 63.880 

 63.886 

 63.936 

 63.910 

 63.946 

 63.930 

 63.942 



63-893 

 63923 

 63.924 

 63-893 

 63.944 

 63.938 



63.9'5 

 63.946 



63-949 



Mean, 63.916, .0032 



Bucher gives a rather full discussion of the presumable errors in this 

 method, which, however, he regards as somewhat compensatory. 

 11 



The 



