Kennicdy — Large tons a>id Condensation-Nuclei from Flames. 59 



of experiments carried out with the object of obtaining more information 

 on the nature of the large ion and the nucleus from which it is formed. The 

 general method of working was to determine the number of condensation- 

 nuclei by Aitken's apparatus, and to measure the quantity of ionization by an 

 electrometer. One of the results obtained is that the charge on the large ion 

 is not the simple electronic charge, but some multiple of it. It will be con- 

 venient, howcA^er, to consider the quantity of electricity per c.c. of either sign 

 as being equal to iVk, where £ is the electronic charge. N will not, therefore, 

 as assumed in the previous papers, be the number of large ions of one sign 

 per c.c. of the gas. 



Disappearance of the Large Ions. 



In experiments on the variation of the ionization with time, a gasometer 

 of about 450,000 c.c. capacity was rapidly filled with the gas from a Bunsen 

 flame burning under the funnel-shaped vessel, illustrated in fig. 1. When 



Fig. 1. 



filled, the gasometer is connected to the measuring apparatus, which consists 

 of a brass tube A (fig. 2), and an insulated concentric rod -B, connected with 



-% 



^ 



Fig. 2. 



the electrometer. An air-current of about 60 c.c. per second is sent from the 

 gasometer 'through A, which is charged to about 600 volts, sufficient to remove 

 all the ions from the air-stream. Measurements were taken at intervals for 

 about three hours after filling the gasometer, and the values of N deduced, 

 assuming for e the value 4'77 x 10"'" E. S. units. The result of such an 

 experiment is given in the following table : — 



[9*] 



