208 



THE ATOMIC WEIGHTS. 



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

 joined : 



Th{SO^)^. ThO.,. Percent. ThO.. 



1. 1630 -7245 62.295 



.8607 -5362 62.298 



I. 5417 .9605 62.301 



I. 5217 -9479 62.292 



Mean, 62.297, ± .0013 



Nilson's series, 62.297, ± .0009 



Cleve found, 62.423, dr .0140 



General mean, 62.298, dz .0007 



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

 of thoria, which, combined as usual, give a general mean of ThO.^ = 

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



) 2BaS04 : ThO^ : : 100 : 58.026, ± .214 



) 2BaS0, : Th(S0,).,.4H,0 : : 100 : 107. 509, ± .585 



) 4CO2 : ThO^ : : 100 : 151.114, ± .053 



) Percentage of ThOj in Th(SO^)2.9H20, 45.090, db .0019 



) Percentage of ThO., in Th(S0J,.4H.p, 52.535, ± .0473 



) Percentage of Th02 in Th(SO^)2.62.298, =b .0007 



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

 of thoria are calculable : 



0= 15-879, ±.0003 



S = 31.828, zh .0015 



C = 11.920, d= .0004 

 Ba = 136.392, =h .0086 



The values for Th02 a^"© — 



Chydenius' determinations Th02 = 265.103, ± .3394 



From (r) 



From (2) 



From (3) 



From (4) 



From (5) 



From (6) 



General mean ThOj = 262.626, ± .007 1 



Hence Th = 230.868, ± .0071. 

 If = 16, Th == 232.626. 



