o6 Journal of the Mitcheu, Society. [March 



ration of the thorium into three fractions of different atomic 

 weights. The atomic weight of genuine thorium is there- 

 fore not yet established. 



I wish to express my sincere thanks to Professor Chas. Bas- 

 kerville not only for his sympathy and assistance in the work, 

 but for the privilege of taking part in an investigation, which 

 has been so fruitful in its results. 



University of North Carolina. 



