618 Dr. EL Geiger and Mr. J. M. Nuttall on the Ranges 



It has been already pointed uut by Rutherford * in 1907 that 

 possibly a relation exists between these quantities. It 

 appeared that the range of the a particles was greater the 

 smaller the period of transformation of the substance. There 

 were, however, several products for which this relation did 

 not seem to hold. 



In order to find any possible relation between the range 

 and the period we have plotted in fig. 3 the logarithms of 



o 



+6 









Fig. 3. 





















/ 



*% 















AdA 

















-% 











/ 



y^ct.Em. 













BaXTy 



fee 





c> 









ItaErou 



/J 







u 









Pol./ 



y •Radft 



d. 





-10 



-ft 









/ / 











Ret? 



/ 











/ 



•Ur. 











* -5 -6 -7 -8 



Logarithms of ranges. 



the transformation constants of the different products against 

 the logarithms of the corresponding ranges for the pro- 

 ducts in the uranium-radium series and in the actinium 

 series. The data from which these curves are plotted are 

 given in the following table. For convenience the initial 

 velocity of expulsion is added as well as the half- value period 

 and the transformation constant. The ranges are reduced to 

 0° centigrade. 



* E. Rutherford, Phil. Mag. xiii. p. 110 (1907). 



