376 



Mr. H. A. McTaggart on 

 Propionic acid and water. 



Cone. 



Diam. 



Time. 



Volts/cm. 



10- 4 



•10 



30se cs 



35 



10~ 4 .l/2 





23 





10 _4 .l/4 





23 





10~ 4 .l/8 





18 





10~ 4 .1/16 





17 





10~ 4 .l/32 





15 





10" 4 . 1/64 





16 





10~ 4 . J/128 





13 





10 " 4 . 1/256 





13 





Water 





11 









Butyric . 



xcid and water. 





Cone. 



Diaua. 



Time. 



Volts/cm. 



10~ 6 





14 



22 sees. 



40 



10~ 6 .2 





12 



40 





10" 6 



3 





14 



30 





10" 6 



4 





12 



50 





10" 6 



5 





12 



69 





10" 6 



6 





12 



33 





10" 6 



7 





14 



32 





10~ 6 



8 





14 



32 





10 -6 



9 





12 



29 





10~ 5 



•12 



30 





In the last table the solutions were each made separately 

 and not by successive dilution as in the other cases. 



On account of the difficulty of getting readings fairly 

 consistent, only the most general comparison of the effects of 

 these acids on the surface charge can be made. They all 

 lower the charge as do inorganic acids, formic and butyric 

 acting more vigorously than the others. They show parallel 

 activity in lowering the surface tension. They exhibit with 

 the alcohols the variation of charge with the size of the 

 bubble. 



Discussion. 



The addition of alcohols to water reduces the electrification 

 at the liquid-gas surface, the effectiveness of anv alcohol 



