228 Mr. E. Jacot on a Relation between Ionization by 



This ratio, which we will call N, is the number of pairs 

 of ions made by a ray in crossing the chamber. Knowing 

 I and p we derive a, the specific ionization produced by one 

 corpuscle travelling 1 cm. in nitrogen at a pressure of 

 1 mm. of mercury. 



Results. 



The results of the experiments are shown in Table III. 

 Column 1 gives the pressure throughout the apparatus in 

 mm. of mercury ; column 2 the current passing through the 

 solenoid during each successive experiment ; column 3 mean 



values of the ratio — — - = N, the number of pairs of ions 



C\ + c 2 



made by a corpuscle in crossing the chamber. 



Table III. 



1. 



2. 



3. 



4. 



Pressure p, 

 mm. of Hg. 



Solenoid current, 

 amps. 



N. 



N 



•083 



4-3 



4-7 



1-83 

 1-53 



221 



18-4 



•064 



4-3 

 4-7 

 51 



1-41 

 l-]9 

 1-02 



221 



18-6 

 15-9 



•050 



4-7 

 5-1 

 5-5 



•92 

 •78 

 •67 



18-4 

 157 

 134 



•041 



51 



5-5 

 60 



•65 

 •56 



•47 



15-9 

 136 

 11-4 



•035 



5-5 

 60 

 6*5 



•48 

 •40 

 •35 



13-8 

 114 

 100 



•030 



5-5 

 60 

 65 



•40 

 •35 

 •31 



134 

 11-5 

 102 



•028 



6-0 

 6-5 

 70 



•32 

 •29 

 •25 



11-6 



10-4 



90 



•025 



65 

 7-0 



•25 

 •23 



100 

 92 



In fig. 4 the values of N have been plotted against the 

 values of p for various velocities of the rays. The curves 



