208 THE 'ATOMIC WEIGHTS. 



upon material obtained from a different source. The new data are sub- 

 joined : 



Th(SOJ v ThO 2 . Percent. ThO.,. 



1.1630 .7245 62.296 



.8607 .5362 62.298- 



1.5417 .9605 62.301 



1.5217 .9479 62.292 



Mean, 62.297, .0013 



Nilson's series, 62.297, .0009 



Cleve found, 62.423, zb .0140 



General mean, 62.298, .0007 



From Chydenius' work we have four values for the molecular weight 

 of thoria, which, combined as usual, give a general mean of Th0 2 = 

 265.103, db .3394. We also have the following ratios : 



(I.) 2BaSO 4 : ThO 2 : : ZOO : 58.026, dz .214 



(2.) 2BaSO 4 : Th(SO 4 ) 2 .4H 2 O : : 100 : 107.509, .585 



(3.) 4CO 2 : ThO 2 :: 100 : 151.114, .053 



(4.) Percentage of ThO 2 in Th(SO 4 ) 2 .9H 2 O, 45.090, =b .0019 



(5.) Percentage of ThO 2 in Th(SO 4 ) 2 .4H 2 O, 52.535, .0473 



(6.) Percentage of ThO 2 in Th(SO 4 ) 2 .62.298, =h .0007 



Reducing with the following data, seven values for the atomic weight 

 of thoria are calculable : 



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



S = 31.828, .0015 Ba = 136.392, .0086 



The values for Th0 2 are 



Chydenius' determinations ThO 2 265.103, -3394 



From(i) =268.937, -9919 



From (2) " rr= 268.021, 2.7115 



From (3) " =264. 1 20, dr .0927 



From (4) " =262.641, .0149 



From (5) " = 255.061, .3426 



From (6) " =262.613, .0081 



General mean ThO 2 = 262.626, .0071 



Hence Th = 230.868, .0071. 

 If = 16, Th = 232.626. 



