Nolan — Mobilities of Ions Produced by Spraying. 23 



Summary of Eesults. 



1. When the distilled water is sprayed by air, ions of the following 

 mobilities are obtained :— -00038, -0010, 0043, -013, -040, -12, -24, -53, 

 1-09, 1-56, 3-27, and 6-5 cm. /sec. in a field of 1 volt /cm. 



2. These ions are found carrying both positive and negative charges except 

 the fastest (mob. = 6'5), which has not been found with a positive charge. 



3. The mobility of the ions does not change with time within a certain 

 considerable range. 



4. The negative ions exceed the positive in the ratio of 5 : 4 for the 

 slower ions, varying to 2 : 1 for the faster groups. 



The writer wishes to express his indebtedness to Professor M'Clelland, to 

 whose suggestion this research is due, for his interest and advice. 



