214 Prof. F. Soddy and Miss A. F. R. Hitchins on the 



Results. 

 The results of the measurements of the quantities of radium 

 in the four preparations from the start are shown in the 



following tables. 



Preparation No. I. 

 255 grms. Uranium. Purified October 24, 1905. 



Date. 



Time from 



start (years). 



Leak (divs. 

 per minute). 



Constant 



(grms. Rax 10-12 



required to give 



1 div. per min.). 



Radium 

 (grms. X 10-12). 



Mean of first 9* tests 

 June 9, 1908 



to 0-85 



2-62 



13 

 3-2 ") 



12 



5-78 



5-2 

 5-25 

 53 

 5-35 



1446 



1566 



16 

 19 

 18 

 20 

 20 

 23 

 24 

 23 

 25 

 24 

 25 

 24 

 34 

 33 

 39 

 38 

 37 

 35 



Aug. 8, 1908 



Sept. 25, 1908 



Nov. 20, 1908 



May 5, 1909 



2-78 

 295 

 307 

 3*53 

 364 

 3 - 75 

 384 

 3-93 

 3-96 

 461 



317 



339 



344 



3-92 



4-2 



40 



4-28 



416 



4-4 J 



- 



June 14,1909 



July 27, 1909 



Aug. 27, 1909 



Sept. 29, 1909 



Oct. 12, 1909 



June 3, 1910 



4-7 



Aug. 19, 1911 



Jan. 20, 1912 



July 30, 1914 



Oct. 21, 1914 



Nov. 26, 1914 



May 5, 1915 



5-82 

 624 

 876 

 8-99 

 909 

 951 



6-5 



62 



733 



262 ' 



2-55 



221 



\ 



* Phil. Mag. [6] xviii. p. 854 (1909). 



Preparation No. II. 

 278 grms. Uranium. Purified August 14, 1906. 









Constant 





Date. 



Time from 



Leak (divs. 



(grms.RaXlO- 12 



Radium 



start (years). 



per minute). 



required to give 



(grms. X 10~ 12 ). 









1 div. per min.). 





May 30, 1908 



1-80 



3-02] 

 3-68 ! 





18 



May 7, 1909 ...... 



2-73 



5-78 



21 



June 25, 1909 ... 



286 



3-72 f 

 40 1 



21 



Oct. 4, 1909 



314 





23 



June 4, 1910 



3-80 



4-28 



5-2 



22 



Aug. 23, 1911 ... 



503 



4-80 



5-25 



25 



Jan. 30, 1912 ... 



546 



512 



5-3 



27 



July 29, 1914 ... 



7-96 



613 



535 



33 



Oct. 22, 1914 



8-18 



2-18 1 

 2-20 J 



14-46 



32 



Nov. 27, 1914 ... 



8 29 



32 



May 7, 1915 



870 



1-84 



15-66 



29 



