y 



T H E 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OP SCIENCE. 



— <* 



[SIXTH SERIES.] 



.MARCH 1913. 



XXXVII. The Chemical Properties and Relative Activities of 

 the Radio-Products of Thorium. By Herbert N. McCor, 

 Ph.D., Professor of Chemistry, and Charles H. Viol. 

 Ph.D.. Assistant in Chemistry, University of Chicago *. 



I* The Chemical Properties of the Radio-Products 

 of Thorium. 



FROM the earliest history of radioactivity it has been 

 recognized that the various active products of uranium, 

 radium, and thorium have more or less definite, characteristic 

 chemical properties. An accurate knowledge of such 

 properties is of much importance in the study of these 

 substances, since it forms the basis for their chemical sepa- 

 ration from one another and from inert matter ; at the same 

 time it may throw some light on the problem of the trans- 

 formation of matter. In attempting to determine the relative 

 activities of the various radio-products of thorium, we found 

 it necessary to study their chemical properties in some detail 

 in order to be able to prepare them in (radioactively) pure 

 form. A great many reactions are recorded in the literature, 

 but, owing to the intricate and novel nature of the problem, 

 some errors have doubtless been made ; so that it becomes 

 important that supposed facts be corroborated by independent 

 observers. 



During the writing of this paper, Soddy's monograph, 



* Communicated by the Authors. Presented, in abstract, at the 

 Eighth International Congress of Applied Chemistry. 



Phil. Mag. S. 6. Vol. 25. No. 147. March 1913. 2 A 



