Currents to the Study of Ionization by Collision. 469 



In the experiments, the results of which are summarized 

 in the following five tables, the ratio between successive 

 values of the current was found to remain practically con- 

 stant over the range of distances used. The mean of these 

 ratios was taken, and from this a was found. The currents 

 at different distances were then calculated, using this value 

 of a, and the calculated values of the current are tabulated 

 for comparison with those observed. The currents are ex- 

 pressed in arbitrary units, they may be reduced to amperes 

 by multiplying by 6*9 x 10 ~ 9 . 



Pressure of air, p = V'86 mm. 



Electric Intensity, X = 410 volts per cm. 



a=-97. 



Distance 



between plates, 



in cm. 



Observed 



Calculated 



Ratio of 



current. 



current. 



successive 

 observed currents. 



■1 



23-0 



23-0 



1-09 



•2 



25-1 



25-3 



112 



•3 



28-0 



27-9 



1-11 



•4 



310 



30-8 



1-10 



•5 



34-0 



33-9 





Pressure of air, p = S'12 mm. 



Electric Intensity, X = 410 volts per cm. 



* = l-63. 



•1 



12-5 



12-5 



1-19 



•2 



149 



14-7 



1-15 



•3 



17-2 



173 



1-21 



•4 



209 



20-4 



1-15 



•5 



24-1 



24-0 





