M'Clelland and Nolan — -Ions produced by Bubbling Air. 61 



An examination of this table brings out some interesting points. It is 

 seen that the mobilities in the case of mercury when undried air is used 

 (columns B and D) agree very well with the values in the case of the water; 

 and also that there are corresponding ions in the alcohol column. When 

 dried air is bubbled through mercury (columns C and E) different ions are 

 found, but these also occur in the alcohol column. The agreement between 

 the numbers throughout the table is very good, with a few exceptions. 



When dealing in a previous paper with the results obtained by bubbling 

 air through mercury we suggested that there might only be five distinct sets 

 of ions, and that the ions found when the air was dried might be transient 

 forms of the stable ions found in undried air after a long interval. A com- 

 parison with the work on water and alcohol now makes it clear that the 

 results with mercury should be set forth as in Table VI, above. The general 

 result brought out by the table is that the ions got by bubbling undried air 

 through mercury also occur when water is sprayed. The ions found when 

 dried air is bubbled through mercury form another set. Both sets are found 

 in the experiments with alcohol. In the experiments with alcohol the air 

 was not dried; neither was it saturated with water vapour. "We are 

 examining further the difference between the ions found with water and with 

 alcohol, and we have also work in progress on the mobilities of the ions 

 formed by phosphorus, which may throw further light on the subject. The 

 explanation of the nature of all these different ions will probably be found 

 along the lines suggested in previous papers :' but we do not propose to go 

 into the matter in greater detail until we have further experimental results. 



1 Proc. Roy. Soc, A, vol. xciv (1917). Proc. Roy. Irish Acad., vol. xxxiii, Sec. A. 



R.I. A. PROC, VOL. XXXIV, SECT. A. [11] 



