﻿Growth of Radium C from Radium B. 



299 



obtained giving ^ ue relation between the ionization produced 

 in the electroscope and the absorbing layer of aluminium. 

 From this curve the values of C'/(J given in Table I. were 

 found. Columns 1, 2, and 3 contain all the data necessary 



Table I. 



Thickness of 



B 



Absorption of 

 RaCJ. 



Absorption of 

 Radium B. 



aluminium in 

 millimetres. 



O 



C 



B 







Oq 



5-0140 







O01Q2 



100 



0-81 



00140 



0-0343 



0-35 



1-00 



00305 



0-2075 



0-050 



086 



0-05 



1-30 



0-0073 



789 



0-06 



1-24 



0-0070 



0-721 



0-09 



092 



0-00112 



0-474 



0-1 



0-85 



0-00595 



0420 



0-2 



0-46 



000465 



0-177 



0-3 



025 



0-00375 



0-078 



0-4 



0-15 



0-00305 



0-038 



0-5 



0-09 



0-0024 



0-0180 



06 



0-06 



00021 



00104 



09 



0045 



0-00125 



00047 



1-3 



0'045 



0-00075 



0-0028 



Fio-. 4, 



eo 



ffif 



o — 



•2 •* -6 -8 l-U 



Ml LLIM£TR£S. 



for calculating the absorption of the jS rays from RaB by 

 aluminium and the absorption produced by differenl thick- 

 nesses of aluminium is shown in column 4. In figure 4 the 



X 2 , 



