60 



THE THEORY OF IONIZATION OF GASES 



and (3=p<f)l-}. Substituting these expressions for 

 \ifi/ 



a and |8 in the equation for S, viz., 



(a-/3)S=loga-log/3, 



a relation 



wi /I )0i ) } = 



Sparking 

 Potential 

 in A-olts. 



600 



4OO 



200 



10 



(p measured in millimetres of mercury. \ 

 S ,, ,, centimetres. j 



Figure 11. 



is obtained, which shows that the sparking potential v is 

 a function of m only. 



24. Effects of initial ionization. 



The determinations of the sparking potentials given 

 in the above tables were made by increasing the potential 

 applied to the electrodes and observing the point at 



