244 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 54 



The work of Morse and Arbuckle ' upon the atomic weight of cadmium 

 was similar in cliaracter and purpose to their work upon zinc. The 

 presence of occluded gases in the oxide was recognized, and in the new 

 determinations they were extracted, measured and analyzed. Cadmium 

 was converted into oxide, and corrections for the gaseous impurities were 

 applied. The vacuum weights of metal and oxide are given below, together 

 with the volume of extracted gas, and the crude, uncorrected percentage 

 of Cd in CdO : 



Mean, 87.508, ± .0003 



This gives Cd = 112.082. Corrected for occluded gases, Cd = 112.377 

 in mean, ranging from 112.359 to 112.395. The correction adds 0.029 

 to the percentage of metal; and if we assume the same correction to the 

 older determinations of this ratio, the several series combine as follows : 



Morse and Jones 87.5356, ± .0003 



Lorimer and Smith 87.5334, ± .0023 



Bucher, 1 87.5365, ± .0024 



Biicher, 2 87.5163, ± .0016 



Morse and Arbuckle 87.5370, ± .0003 



General mean 87.5360, ± .0002 



This combination is equivalent to a rejection of all the data except 

 those of Morse and his colleagues. 



Baxter and Hines," in order to determine the atomic weight of cadmium, 

 resorted to the analysis of the chloride, with all the precautions char- 

 acteristic of the Harvard laboratory. First, the gravimetric ratio 2AgCl : 

 CdCl, was determined, with the subjoined results. Vacuum weights are 

 given throughout : 



Weight CdCh. Weight AgCl. Ratio. 



5.53421 8.65356 63.953 



7.77758 12.16166 63.952 



8.87917 13.88344 63.955 



^ .\nier. Chem. Journ., 20, 536. 1898. See also Arbuckle, Thesis, .Tohns Hopkins University, 1898. 

 ^Journ. Amer. Chem. Soc., 27, 222. 1905. 



