Electrification at Liquid- Gas Surfaces. 



307 



Cr0 3 . 



Time. 



Charge. 





Seconds. 





m~ 8 



20 



^ 



10- 7 



25 



- 



10~ T .5 



m 



r- 



10"" 6 



50 



- 



10~ 6 r 2 



V 



- 



The effect of negative ions on positively charged bubbles 

 was then examined. For this purpose the trivalent and 

 tetravalent ion (Fe0y q ) in potassium, ferric and ferrocyanide 

 were used. To obtain a positively charged bubble to begin, 

 with, a solution containing 10~ 8 equivg./cc. of thorium nitrate 

 was made. In this a bubble of air has a small positive 

 charge. The following tab'es show the effect on this positive 

 charge of the negative ions in different concentrations. 



£ 3 Fe0 7fl , 



Time. 



Charge, 





Seconds. 









slow 



+ 



10~ 8 



,, 



+ 



10~ 8 .5 



1.1 



almost zero. 



10- 7 



— 







10~ 7 .2 



glow 



- 



10~ 7 .3 



40 



- 



E 4 Fe0 76 3JI 2 O. 



Time. 



Charge. 





Seconds. 









slow 



+ 



10~ 9 .2 



j> 



+ 



10 _9 .4 



43 



— 



10 -9.8 



30 



- 



io~ 8 



20 



_ 



10" 8 .3 



28 



— 



10- 7 



37 





X '1 



