and its Products of Iransformation. 



829 



Some other experiments on the decay of radium E will 

 now be described. Some radium E was separated from 

 radium D by precipitation of the latter with barium sulphate, 



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j 







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f 

























/ 



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I 



/ 











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1 

















7 





























J 

 / 



















j 







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tS to ii So 



2 So 6 J 65 



Tii 



and its activity was found to decay, according to an ex- 

 ponential law, with a period of 5 days. The results obtained 

 are shown in Table II. See also fig. 2, curve 2. 



Table II. 





Activities in arbitrary units, initial 



Time in Days. 



value taken =100. 









Experimental. 



Theoretical for 5 

 days period. 







100 



100 



01 



983 



986 



06 



911 



917 



09 



88-8 



88-2 



1-8 



78-4 



77-9 



21 



747 



74-8 



28 



70-2 



67*8 



39 



58-2 



58-3 



50 



495 



50-0 



5-8 



456 



446 



