﻿568 Dr. G. Bakker on the 



The potential function $(ii)=fqe~ qu gives : 



and 

 c n = \ u«yjr(u)du=2>nf( ii»+V*»rft« + ^i u«e-* u du. 



Jo To c l Jo 



2tt/£ I M«r9"dw=— 27T/I ud(e-4 u ) = 2irfue-* u + ^ 7 e-w 

 Ju ' Ju g 



Now the function V of Euler is such that one has 

 ] 

 whence 



and 



r* oo 



r n+2 = u n + l e- u du = 1.2.3...(n— l)n{n + l), 



Jo ( 1 Jo 9 



?l l(7 7i+2 (J n + 2 ) ^ O n+2 



1.2.3...?* ^ l+2 * 



Putting X= -, we find for the system of plane layers, 



according to (18) : 



\fqtmm'e-r = 4tt/\ 2 f ' ^A - 8tt/V f ' ( ^\ 



2 



eta 



2 ( d ^) 2 dh+.... 



H.w 



Further, the TV of the equation (18) relating to the potential 



e~ qr 

 function — /- — — , becomes, according to equation (20) : 



From this equation and equation (18) we arrive at 



Now I have demonstrated above that the superficial tension 

 H is expressed by 



2 dh+.„ 



-iTO* 



(9) 



