ATOMIC "WEIGHTS 517 



From Branner's series Ce = 140.26. 



Braimer discusses at some length the color of eerie oxide, and describes 

 it as nearly white, but with a faint tinge of brownish-yellow. 

 The ratios, good and bad, for cerium now are — 



(1). Ce,(S04),:3BaS04: : 100: 122.958, ± .1139 



(2). 3BaS04:_2CeO,: : 100: 49.360, ± .035 



(3). 3BaCl,:Ce„(S04)3: : 100: 91.625, ± .016 



(4). 3AgCl:CeO,: : 100: 40.469, it .0415 



(5). Percentage CeO, from Ce„(SOJ,, 60.5528, ± .0019 



(6). Percentage CeOo in Ce„(S04).v8H„0, 48.329, ± .0009 



(7). Percentage H„0 in Ce,(S04),.8H„0, 20.278, ±: .0019 



(8). Percentage CeO, from CeACO,):,, G3.4316, ±: .0032 



(9). Percentage CO, from Ce4a0,)„ 48.2546, ± .001 



(10). 3Ag:CeCl3: : 100: 76.167, ± .0065 



(11). 3C,03:2CeO,: : 100: 1.59.471, ± .02.54 



The antecedent atomic weights are — 



Ag = 107.880, ±: .00029 C = 12.0088, ±: .0002 



CI = 35.4584, ±: .0002 Ba = 137.363, ±.0025 



S = 32.0667, ± .00075 H = 1.00779, ± .00001 



Hence, 



From ratio 7 Ce = 139.210, ± .0276 



" 5 140.079, ± .0100 



"10 140.132, ± .0105 



"11 140.247, ±: .0275 



" 6 140.251, ± .0045 



" 1 140.663, ± .2638 



" 2 140.832, ± .1225 



" 3 141.330, ± .0500 



" 8 141.483, ± .0176 



" 9 141.559, ± .0064 



" 4 142.023, ± .1785 



General mean. Ce = 140.583, ± .0032 



This mean appears to be, on chemical grounds, too high, because of 

 the evident overweighting of ratio 9. If we reject all values in excess 

 of 141, the general mean of the remaining seven values is 



Ce = 140.197, ± .0038 



This represents mainly the work of Brauner and Robinson. 



