656 Mr. Shizuwo Sano on the Thermodynamical 



so that g can satisfy the three boundary conditions that 

 ^e—^fj and D vanish at P' and a becomes a' at the same 

 point. At the same time p 1} p 2 , . . . p n , D become definite 

 functions of a, and the distance between the two points at 



which ^- becomes sensibly equal to zero gives the thickness 



of the transition layer. 



It appears to me at present that the case last mentioned 

 contains the most natural assumptions as to the conception 

 of ¥, i. e. (i.) the fluids are electrolytically dissociated, (ii.) F 



depends upon ^, ^, ^, (iii.) F is sensibly independent of 

 ox oy oz 



§r-, < a , ^r- when a becomes either a' or a", although the 

 Ox 0}J oz 



absence of electrolytic ions does not prevent the existence of 



the transition layer. 



In will be remarked that according to this theory the 

 difference of electric potentials between P' and P" is a 

 definite quantity provided- that the physical and chemical 

 conditions at P' are given, and that the condition of the 

 maximum surface tension is quite different from the condition 

 that the difference of electric potentials between P' and P" 

 vanishes, so that it is not probable that these two things 

 always occur at the same time. 



I shall conclude this paper by giving other expressions of 

 surface tension and by describing the expressions for some 

 quantities relating to it, always neglecting the effect of 

 gravity. 



If we write (1) and (4) in the form 



M + ^ e = C,, [i = l,2, ...»], . . (23) 



-F + ^|-+S^|^=/, (24) 



d^ dpi 



where p' denotes the pressure at P', then (8) becomes 



T=^Ydx+p'\dx-^i^ Pi dx. . . . (25) 



In the case of only one independent constituent, so called. 

 (25) can be written 



T = (Fclv +p< Ux - !^ (p dx 



iM'^E+A ! pda9 . . . (26) 

 p p / 



=k 



