CERIUM. 343 



To reduce these ratios we have — 



O =. 15.879, =b .0003 C = 11.920,^^.0004 



CI = 35.179, ± .0048 S = 31.828, liz .0015 



Ag = 107.108, ± .0031 Ba = 136.392, ± .0086 



AgCl = 142.287, ± .0037 



From the ratios, with these intermediate data, we can get two values 

 for the molecular weight of Ce/SOJg, and five for that of CeO,. For 

 cerium sulphate we have — 



From (i) €62(80^3 = 565.404, ±.1670 



From (3).... " =568.304, ±.1054 



General mean Ce.^(S0j3 = 567.478, d= .0S91 



Hence Ce = 140.723, ± .0451. 

 For eerie oxide the values are — 



From (2) CeOj = 171.577, =b . 121S 



From (4) " ^ 172.746, ± .1772 



F>om (5) " ^ 170.879, zh .0115 



From (6) " =172.125,^.0177 



From (9) " =^170.557,^.0076 



General mean CeO.^ = 170.827, ± .0060 



And Ce = 189.069, ± .0061. 



For cerium itself, four independent values are now calculable, as 

 follows : 



From molecular weight of sulphate. . . Ce ^= 140.723, ^ .0451 

 From molecular weight of dioxide ... " ^ 139.069, zb .0061 



From ratio (8) " =r 139.206, drz .0263 



From ratio (7) " = 140.516, ± .0047 



General mean Ce = 140. 1 13, rb .0036 



If = 16, Ce = 141.181. 



It must be admitted that this combination is of very questionable 

 utility. Its component means vary too widely from each other, and in- 

 volve too many uncertainties. Furthermore, Schutzenberger and Brau- 

 ner both impugn the homogeneity of the supposed element, as it ha.s 

 hitherto been recognized. Even if no " meta-elements " are involved in 

 the discussion, it seems clear, on chemical grounds, that the tjvo lower 

 values are really preferable to the two higher, and that ratio (7) receives 

 excessive weight. The general mean obtained is probably a full unit too 

 high. The value 139.1 is perhaps nearly correct. 



