ATOMIC WEIGHTS 



29^ 



45.08 

 44.90 

 45.06 

 45.21 

 45.06 



Mean, 45.062, ± .0332 



Hence Th = 233.34. 



The lower hydrate, 2Th(S04)2.9H20, was more thoroughly investi- 

 gated. The thoria was estimated in two ways: First (A), by precipita- 

 tion as oxalate and subsequent ignition; second (B), by direct calcination. 

 These percentages of ThOj were found : 



^A 



^B 



52.83 

 52.52 

 52.72 

 52.13 

 52.47 

 52.49 

 52.53 

 52.13 

 52.13 

 52.43 

 52.60 

 52.40 

 52.96 

 52.82 



Mean, 52.511, ± .047 



In three experiments with this lower hydrate the sulphuric acid was 

 also estimated, being thrown down as barium sulphate after removal of 

 the thoria : 



1.2425 grm. gave .400 SO3 



1.138 " .366 '• 



.734 " .2306 " 



(1.1656 gi-m. BaSO,.) 

 (1.0665 " ) 



( .6720 " ) 



The figures in parentheses are reproduced by myself from Delafon- 

 taine's results, he having calculated his analyses with = 100, S = 200, 

 and Ba = 857. These data may be reduced to a common standard, so 

 as to represent the quantity of 2Th(SOJ„.9H,0, equivalent to 100 parts 

 of BaSO^. We then have the following figures : 



106.597 

 106.704 

 109.226 



Mean, 107.509, ± .585 



