818 



Messrs. F. Soddy and A. S. Russell on 



The results obtained with the various preparations are 

 summarized in Tables I. and II. 





Table I. — Decay of /3-Rays. 





No. 



Preparation. 



Coyer. 



Days under 

 observation. 



X(day) \ 



1 ... 



B (1st Separation, Dec. 1908) 





to 236 



0-0283 



2 



A (4th Separation, Sept. 1909) 



0-028 cm. Zn 



to 129 



0-0289 



3 ... 



B (4th Separation, „ ) 



bare 



Oto 58 



0-0281 



4 ... 



C (4th Separation, ,, ) 



bare 



to 140 



0-0281 



5 ... 



D (4th Separation, ,, ) 



0-028 cm. Zn 



to 140 



0-0283 



6 ... 



f ABO (3rd Separation) 1 

 \ together, distance 115 cm. J 



0-010 cm. Zn 



79 to 220 



0-0282 



7 ... 



Ditto., distance 135 cm. 



0010 cm. Zn 



220 to 287 



0-0282 



8 ... 



f A (4th Separation) j 

 \ distance 115 cm. J 



bare 



to 132 



0-0287 



9 ... 



Ditto., distance 13 - 5 cm. 



0-023 cm. Pb 



132 to 193 



00281 



10 ... 



f BOD (4th Separation) } 

 \ Composition results / 





to 192 



0-0281 



Fig. 1. 



DAYS — • 

 25 50 



150 175 200 



Nos. 6 and 7; 8 and 9; and 10 are the principal results 

 in the above Table. Curves L, II. and III. of fig. 1 corre- 

 spond to them respectively. In No. 10, B, C, D were care- 

 fully prepared with activity in the ratio of about 1 : 10 : 100, 

 by evaporating down aliquot portions of the same solution. 



