WILLIAM D. HARKINS 



167 



The equation of Gibbs, which gives the number of gram molecules (u) absorbed 

 per square centimeter of surface formed, may be expressed: 



I 87 



RT d In a 



.08 



< 



Fig. 19. — Effect of time on the drop weight (surface tension) of decylic acid, 0.0015 N 



Form. ; 

 Acetic 

 Prop/ on I c 



'ric 



Va/en 

 CoprdfC 



Hepti/(c 



NONl/i 



Decy/ 



c 



-a 



-1 



■ WatS/- 



LoK of Concentration 



Fig. 20. — Adsorption curves for fatty acids 



