﻿<y Radiation from Radium B. 



309 



This equation represents the variation of activity as measured 

 through 23 cms. of lead. 



I. 



II. 



III. 



IV. 



1 

 V. 





Calculated rise 



Calculated rise 



Calculated fall of Calculated fall of 





of Radium C 



of ionization by 



Radium C after 



ionization by y 



Minutes. 



from pure 



y rays for ex- 



removal from 



rays for experi- 







emanation. 



perimental case. 



emanation. 



mental case. 



o-oooo 



0000 



1-0000 



1-000 



2 



•000252 



•00143 



■9995 



•998 



3 



•000801 



•00323 



•9989 



•997 



4 



•001770 



•00570 



•9978 



•994 



5 



•003239 



•00885 



•9963 



•991 



6 



•005244 



•0126 



•9942 



•987 



8 



•01097 



•022 L 



•9884 



•978 



10 



•01899 



•0338 



•9805 



•966 



12 



•02925 





•9703 





14 



•04154 





•9582 





15 





•0719 





•929 



17 



•06343 





•9368 





20 



•08876 



•118 



•9120 



•884 



25 



•1368 



•170 



•8650 



•833 



30 



•1897 



•225 



•8134 



•779 



40 



•3015 



•338 



•7046 



•669 



50 



•4118 



•446 



•5985 



•566 



60 



•5125 



•543 



•49S7 



•469 



70 



•6021 



•629 



•4112 



•385 



90 



•7440 



•763 



•2719 



•253 



120 



•8775 



•888 



•1396 



•129 



150 



•9468 



•952 



•06913 



•0639 



180 



•9800 



•982 



•03347 



•0308 



240 



•9994 



1-00 



•00752 



•00691 



258 



1-000 



1-00 







270 







•00352 





Column IV. gives the number of atoms of radium C left 

 in a vessel at different times after completely removing the 

 emanation which has been confined in it for a long time. 

 The numbers are calculated from the equation 



N 



_ -x.rf— ^2^ 4 X 1 e 



l-00891^(x i -x 1 )iv 



X =1,2,3,4 



\J 



,\ 1 )^X,-X 1 ) 



This equation gives the fall of activity measured through 

 2*3 cm. of lead. 



Column III. gives the ionization at different times after 

 the introduction of pure emanation on the assumption that 



