Ionization by Spraying. 



385 



quarter of a minute, during which period about 1800 c.c. of 

 air entered the electroscope, whose volume is approximately 



Fiar. 3. 



4 Minutes * 



20,000 c.c. Each curve represents a single actual obser- 

 vation; the abscissae are minutes, and the ordinates, measured 

 from the top line, are the microscope readings of the gold 

 leaf, with the natural leak deducted. In order to save space, 

 and for the sake of clearness, each curve has its origin at its 

 upper end. The fall of potential during the first quarter of 

 a minute of pumping is ruled a straight line, because the 

 conditions are not steady during that period. It will be seen 

 that the curves for positive and negative ions for acetic acid 

 are identical. The same is true of amyl alcohol, and ethyl 

 alcohol, so that it is not necessary to publish more than one 



