246 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



Weight CdBr^. Weight Ag. Weight AgBr. Ag ratio. 



11.46216 9.08379 15.81319 126.182 



6.82282 5.40724 9.41267 126.182 



6.75420 5.35277 9.31830 126.181 



1 7.08588 ^5.61597 '9.77649 126.174 



5.13859 4.07226 7.08933 126.183 



5.84324 4.C3072 8.06130 126.183 



5.99704 4.75259 8.27360 126.183 



5.90796 4.68200 8.15070 126.183 



Mean, 126.181. 

 ± .0009 

 From the Ag ratio, Cd= 112.42. 

 From the AgBr ratio, Cd= 112.41. 

 And Ag: Br:: 100: 74.082. 



These ratios combine with former series as follows: 



Silver Ratio. 



Huntington 126.076, ± .0052 



Baxter, etc 126.181, ± .0009 



General mean 126.178, ± .0009 



Silver Bromide Ratio. 



Huntington 72.4216, ± .0028 



Bucher 72.464, ± .0035 



Baxter, etc 72.4836, ± .0005 



General mean 72.4813, ± .0005 



AgBr ratio. 

 72.485 

 72.486 

 72.483 

 72.479 

 72.483 

 72,485 

 72.484 

 72.484 



72.4836, 

 ± .0005 



The determinations of the atomic weight of cadmium by Meaglia ^ 

 were based upon the quantitative precipitation by that metal of silver 

 from a sulphate solution, and gold from a solution of sodium chloraurate. 

 With Ag = 107.93 and Au=: 197.2 tlie folloAving values for cadmium were 

 obtained : 



Silver series. Gold series. 



112.37 

 112.56 

 112.45 

 112.38 



Mean, 112.44, 



.0295 



112.41 

 112.45 

 112.65 



112.47 

 112.48 

 112.40 

 112.42 

 112.41 



Mean, 112.461, ± .0196 



From the silver series, with Ag= 107.88, Cd = 112.-39. 

 From the gold series, with Au = 197.269, Cd = 112.50. 



* This analysis is rejected by the authors. 

 " Thesis, University of Grenoble, 1907. 



