388 



Mr. A. S. Eve 



ascertain the underlying cause o£ the relative ionization 

 powers of different liquids. Surface tension, and the extent 

 to which liquids are volatile, do not appear to be main factors. 

 Some liquids evaporated so rapidly that they froze on the 

 vertical nozzle of the sprayer and stopped its action. When 

 working with ether, or chloroform, or benzine, or methyl iodide, 

 the sprayer needed constant refilling. But water or benzyl 

 alcohol will last for days or weeks. The more volatile did 

 not differ in their ionizing powers from the less volatile sub- 

 stances of the same character. Benzine gave low values, 

 ether high. The amount of liquid evaporated did not seem 

 to be an important factor. The number of ions generated is 

 a function of the air velocity, and of the time of its con- 

 tinuance until a maximum is reached. Again, when the 

 sprayer, containing water, was placed in a vessel of water, 

 which was heated from the room temperature to boiling-point, 

 the change did not affect the ionization due to spraying. 

 The small values obtained for the benzine group suggested 

 di-electric capacity as the main cause, but the figures given 

 in the left column, Table II., taken from Drude, vol. xxiii. 

 p. 267, Zeit. Pliys. Chem., do not entirely confirm this view, 

 water and chloroform being out of place. 



Table II. 

 Relative Ionization. 



Dielectric. 



23 



2-0 



9-7 



81 



21 



5 

 21 



34 

 14 



26 



Substance. 



Negative. 



Mercury 



Toluene 



Rhigoline 



Carbon bisulphide 



Benzine 



Sea salt and water , 



Caustic soda and water 10 °/ .. 

 Sodium carbonate and water .. 

 Hydrochloric acid and water . . 



Phenetol 



Turpentine 



Ammonia water 



Tap water 



Distilled water 



Amyl acetate 



Acetone 



Aldehyde „ 



Chloroform 



Acetic acid 



Methyl Iodide 



Methyl Alcohol 



Amyl Alcohol 



Ethyl Alcohol 



Ether 







•02 



•07 



•07 



•11 



•01 



•02 



•07 



•04 



•13 



•11 



•67 



•62 



1-6 



1-9 



2-4 



2-5 



2-7 



3-7 



37 



4-0 



4-5 



4-6 



5-0 



Positive. 





 •02 



•03 

 •07 

 •08 

 •015 



•04 

 •13 

 •04 

 •45 

 •50 



1-0 



1-9 



24 



2-5 



2-7 



3-7 



37 



40 



4-5 



46 



37 



