12 



The Ionization Remaining in Gases after Removal 

 FROM THE Influence of the Ionizing Agent. 



By J. P. V. Madsen, D.Sc, B.E. 



[Read April 7, 1908.] 



Introduction. 



Tu a paper by Professor Bragg and Mr. Kleeman,(i^ 3 

 theory of initial recombination was advanced to explain the 

 cause of the lack of saturation in gases exposed to the action 

 of the o particles of radium. The effect was found to be 

 due to the immediate action between a parent molecule and 

 the electron which was ejected from it as a result of the 

 ionizing influence of the a particle. It was shown that it was 

 easy to reconcile with this theory the result of an experiment 

 described by Professor Rutherford, '2) which suggested that it 

 is easier to obtain the saturation current in a gas when the 

 gas is quickly removed from the influence of the ionizing agent 

 before testing. Rutherford's experiment would, of course, 

 indicate that the process of initial recombination would be 

 completed in a very short time after a molecule had been 

 ionized. However, as explained in a later paper by Professor 

 Bragg, '^^ it was not essential to the theory of initial recom- 

 bination that the process should be completed within any set 

 time, in which case man}^ important considerations would 

 result. 



The author undertook the repetition of Rutherford's ex- 

 periment, and the non -success of some preliminary attempts 

 led to the further suggestion that for a certain length of time 

 it was conceivable that the positive and negative ions might 

 remain in a state of incomplete combination, their final re- 

 combination being precipitated by some change of conditions. 

 The existence of such partially combined pairs of ions would 

 help to explain much of the mechanism of phosphorescence, 

 and would appear to have some connection with the cluster.s 

 described by J. B. B. Burke,'"" which were the product of 

 ionization, and gave rise under some conditions to phosphor- 

 escent glov7, contained energy, and yet were not electrified. 



(1) Trans. Roy. See, S.A., vol. xxix., 1905. 



(2) Phil. Mag., vol. 47, p. lo8. 



(3) Phil. Mag., May, 1906. 



(4) Phil. Mag., vol. i., p. 342, 1901. 



