McClelland and Nolan — Ions Produced bij Phosphorus. 



Undried Air. 



In the first series of experimenta the time-interval between the formation 

 of the ions and the nicasuremeiit of their mobilities was varied from I'.Ssecs 

 to 63 sees. Ordinary room air which was not dried, but which had passed 

 through the cotton-wool plug, was used. The numbers obtained were very 

 steady. This was a rather unexpected result, as E. Bloch was unable to get 

 steady numbers until he dried the air. The results oljtained are shown in 

 Table I. The mobilities are given in cms. per. sec. under a field of one volt 

 per cm. 



Table I. 



TiMP 



■017 



•0069 



■0041 



•0021 F 



•0013 



■00066 



■00033 





sees. 



















1-3 













■00063 



■00031 

 •00032 





4-6 





■0071 

 •0081 



•0035 



■0023 .' 



•0012 



■00055 



•00031 





16 





■008.3 



•0041 



■0022 



•0010 



■00055 



•00031 

 •00029 









•0037 



■0024 



•0011 



•00064 



•00031 











•0046 



•0024 



•0011 



•00068 



•0002S 





19 







•0037 

 •0049 



•0027 



•0013 

 •0013 



•00067 



■00029 

 •00032 



















•00033 



•00016 

















•00030 



•00014 



63 

















•00014 

 •00015 

 •00014 



Means, 



■017 



•0076 



•0041 



•0024 



•0012 



•00063 



•00031 



•00015 



Just as in the case of the ions derived from alcohol we see that the ions 

 due to phosphorus can be divided into a number of groups, and that the 

 mobility of an ion of any particular group does not change with time. As 

 the time-interval is increased, it becomes difficult to observe the faster ions. 

 When 19 sees, have elapsed, the two classes of highest mobilities previously 

 observed cannot be detected. (The numbers given for a time-interval of 

 63 sees, are not exhaustive. Ions of liiglier mobilities than ■00031 were present 

 and gave about one-third of the ionisation. Their mobilities were not, how- 

 ever, measured.) With, a time-interval of 63 sees, we find an ion of mobility 



[1*] 



