108 



Proceedings of the Royal Irish Academy. 



nuclei per c.c. was 22'6 x 10'. In the following table four determinations 

 of 1} based upon the decay curve are given : — 



N 



dN 

 It 



aiV2 



dt 



dt 



150 X 10' 



75 X 10' 



36-4 X 10' 



38-6 X 10' 



11-5 X 10-^ 



200 



108 



65 



43 



9-5 



300 



217 



145 



72 ■ 



10-6 



400 



348 



258 



90 



10-0 



'/OO 



U 





















BOO 

 dOO 



TOO 



900 

 300 



'too 



ia> 











































































































\ 















3W 



£00 









^ 























\ ^ 



X. 





















^ 







^^ 



. A 















S^corvcU 







^ 

















L 







5 



^ 



i- 



5 



Fig. 6. 

 These figures show that over a considerable range the recombination 

 coefficient has a fairly constant value of about 10 x 10"^ If, however, the 



