724 



Dr. R. W. Boyle on the Behaviour of 



The method of performing an experiment was to condense 

 the emanation at the extreme end C of the containing tube 



Fiff. 1. 



TO BHTTZRY 



mfl 



P£/Y7V?<V£\ 



B 



A 



by immersing this end in a bath of pentane cooled with 

 liquid air. Condensation was maintained for four hours, 

 during which time the active deposit about the tube practi- 

 cally all decayed, and the ionization gradually decreased to 

 a small constant value. The double right-angled bend in 

 the tube at B prevented the a-rays from the condensed 

 emanation and its active deposit at C having any ionizing 

 effect in the vessel above. 



After keeping the emanation condensed for four hours the 

 temperature was allowed to rise slowly, and continuous ob- 

 servations of ionization were taken. Under these conditions, 

 whenever any of the condensed emanation at C volatilized, 

 the emanation vapour quickly distributed itself throughout 

 the tube, and the portion of it going to the upper part AB 



