﻿Thorium and Radium Emanations. 



355 



and 



Activity after 3J hours = 



.-. Value of N = 



Lxr ' 7 ^ = 



Lxr 5X = 



•.E T =N-Lr^ = 



M-0-326(N-L*" 5 *) -Le-°-^ 

 = 75-7-8-05-20-35 = 



44*8 d.p.m. 

 40*0 d.p.m. 

 20-35 d.p.m 

 15*30 d.p.m. 



24-70 d.p.m. 

 47-30 d.p.m. 



Fig. 10. 



Time ?r» mtrtkvtcs, . 



4- % a 



10 



Example of observations used to plot curves shown in Fig. 12. 



Since the experiment was performed one day after the 

 chosen time this last quantity has to be multiplied by 1*2 to 

 eliminate the effect of decay. This gives ihe value of G T to 

 be 56*6. It was found in other determinations that E R and 

 E L were respectively 6*3 and 57*5 and that Gr R and G L were 

 10 # 9 and 101*8. The fraction of thorium emanation condensed 

 at -159°' 5 C. is therefore 



^7-6"3 - 0-359 • 

 57-5-6-3 - UJ0J > 



and of radium emanation at the same temperature, 

 56-6-10-9 



101-8-10-9 



= 0-503, 



Variation of the fraction of the emanations condensed at 

 liquid-air temperature with lapse of time. — Another compli- 

 cation arose, however, in this experiment from a cause 



2 A 2 



