On the Theory of Electrocqpillarity . 363 



0, while p is a function of N 3 only. Therefore A must be a 

 function (approximately li#) of 0. Equation (1), however, 

 may be put in the form 



p„= Pl e'*(l+^, (3) 



where p± and p D are the densities of liquid and vapour 

 respectively. 



mt'i 2 



2. Since B=-^j5- and at the critical temperature, p v =p l9 



it follows from equation (3) that at this temperature 



2 



"rtTr"==0. Hence c\ must be a function of the temperature 



and cannot bear a definite relation to the molecular velocity 

 at the critical temperature. 



3. The agreement of the equation deduced with observed 

 •data cannot therefore be considered as justifying the original 

 assumptions since additional assumptions are introduced. 

 Considering the equation purely as an empirical one, the 

 agreement with observation does not appear sufficiently good 

 to make it of value. 



Respectfully, 



Department of Commerce, CYRIL H. MEYERS, 



Bureau of Standards, « • , , -ni • • , 



April 15, 1920. Assistant Physicist. 



XLII. On the Theory of Electrocapillarity : I. 

 By Alexander Frumkln *. 



Symbols used throughout this communication : — 

 P is the ionic solution pressure. 

 p is the osmotic pressure, 

 y is the surface-tension. 

 e is the electric charge on unit surface. 



\jr is the potential difference between a decinormal calomel 

 electrode and the mercury in the solution. 



r rHE classical theory of electrocapillarity of Lippman- 

 -L Helmholtz, which considered the process of polarization 

 as the charge of a condenser, led to the following equation 

 of the electrocapillary curve 



U-- « 



* Communicated by the Author. 

 2B2 



