loNIZATION BY POSITIVE loNS 



43 



The currents are given in arbitrary units, and the 

 values of a and /3 may be found from the ratios of the 

 currents at three distances. The agreement between the 

 expression for n involving a and /3 and the currents over 

 several distances shows that the experiments are 

 accurately explained by the theory. 



The above example of currents developed in air, 

 in which p=l, X=350, a=5*25, and /3 = '0141, may 

 be compared with the results of an experiment in 

 which p=%, X=700, since according to the theory 

 a and /3 should in this case have twice the above 

 values, and the current corresponding to any distance 

 should be the same as that at double the distance in the 

 previous experiment. 



Table XIII. gives the values of the currents q in this 

 case. 



TABLE XTH. 



The third line gives the calculated values when 

 a=10-5 and /3='0282. The currents at 1, 2, 8, 4, 

 and 5 millimetres are the same as those in the 

 previous experiment when the distances were double 

 these values. 



For comparison with other gases the following examples 

 may be taken from among the experiments which have 

 been made with hydrogen. 



