fO Proceedings of the Royal Irish Aeadeiny. 



A number of determinations of the charge was made also from the decay 

 curves of N, n, and n„, the gas in these experiments being drawn very rapidly, 

 as in fig 1, into the gasometer, and tested at intervals for two or three hours 

 afterwards. From the decay curves, the values of N, n, and Uo are obtained 

 at any time, and the charge calculated. In all such observations the value 

 obtained for B was very much greater than in the experiments when the gas 

 was drawn slowly from the flame, its magnitude varying from about 4'5£ 

 to 6f. 



There is no doubt, therefore, that the large ion bears a charge which is a 

 mvdtiple of the electronic charge. The magnitude of the charge seems to 

 depend on the circumstances under which the ion is formed. There are 

 several reasons for believing that the formation of the nucleus does not 

 depend on the presence of the charge. Experiments made on the number 

 of nuclei in the flame-gas show that the number is not diminished appreci- 

 ably by the removal of the ions just as the gas leaves the flame. The gas is 

 then at a very high temperature, and the molecular groupings forming the 

 nuclei have not been formed before the ions are removed ; and yet their 

 growth is not apparently affected thereby. The charging of the nucleus 

 seems to be an accident, not essential to its formation, but occurring owing 

 to the enormous number of free ions of very high mobility in the flame and 

 the gas coming from it. Considering the charging to take place in this way, 

 it is very easy to understand the formation of multiply charged ions, and it is 

 to be expected that the average charge on the nucleus should depend on the 

 number of free ions of high mobility present when the nuclei are in process 

 of formation. The much higher value of the charge E, obtained above from 

 the decay curves of iV,?i, and Uo, might be explained by the consideration that 

 in all these experiments the gas was drawn from the flame with great rapidity 

 into the gasometer. The gas therefore cooled rapidly, and the nuclei were 

 formed when there was a much greater number of free ions present than in 

 the first series of experiments, where the cooling of the gas was slower and 

 the nuclei had not been formed before a comparatively great number of the 

 free ions had disappeared by recombination. 



An estimate of the charge on the large ion may be deduced directly from 

 the constants of decay /3 and y of the charge per c.c. and the nuclei, assuming 

 that the rate of disappearance of the nuclei is not affected by the charge. 

 For, suppose the charge per c.c. is Ne, then 



If there are iic charged nuclei of either sign, each carrying a charge equal to 



