Active Deposit of Radium in Electric Fields. 539 



(5) The hard y rays in radium D possess from 17 to 35 

 per cent. of the total y energy belonging to radium D. 



(6) The distribution of energy in radium B + radium C in 

 equilibrium is 1 : 45 : 639 for the soft rays from radium B, 

 the hard rays from radium B, and the rays from radium C. 



In conclusion, I wish to express my warmest thanks to 

 Sir Ernest Rutherford for suggesting this research, and for 

 his kind advice and help during its progress. 



University of Manchester, 

 July 19] 4. 



LV1. The Distribution of the Active Deposit of Radium in 

 Electric Fields*. By H. P. Walmsley, M.Sc. 



IT has long been known that the active deposits from the 

 emanations of thorium and radium are concentrated on 

 the cathode in a strong electric field, but that in the case of 

 radium there always appeared from 5 to 10 per cent, on 

 the anode. In the case of actinium it has been shown 

 that under suitable conditions practically the whole of the 

 active deposit is also concentrated on the cathode. Recent 

 detailed work by Wellisch and Bronson f has confirmed the 

 view that the case of radium is anomalous. The present in- 

 vestigation was undertaken to obtain more information on 

 this anomaly. 



Fiff. 1. 



The apparatus consisted of two similar cylindrical brass 

 chambers A and B (tig. 1), connected together by a metal 

 T-piece which fitted into ebonite stoppers closing one end of 



* Communicated bv Sir Ernest Rutherford, F.R.S. 



t Wellisch & Bronson, Phil. May. xxiii. p. 714 (1912). 



