8 



THE THEORY OF IONIZATION OF GASES 



obtained for the different distances are the same within 

 the limits of experimental error. 



The curves, 1 figures 3 and 4, may be taken as 

 examples. In each figure the curve corresponding to a 

 distance of two centimetres between the plates rises 

 more rapidly than that corresponding to one centimetre, 



160 240 320 40O -160 660 



Volts per centimetre. 



Current-electric force curves for air at !! mm. 

 pressure, with distances of 2, 1 and -5 cms. 

 between the plates. 



Figure 3. 



and in the curve corresponding to *5 centimetre the rate 

 of increase with the force is much less than in either of 

 the other two cases. It will be noticed that the curves are 



1 The sets of curves at different pressures may be found in the 

 paper Philosophical Magazine, February, 1901. 



