( 567 j 
But this quantity pds, including the formation of a new double- 
layer, this formation must have been rendered possible by transition 
++ 
of the required number of Hgy-ions from the solution into the mer- 
cury. [We will namely first discuss the case that the mercury is +, 
the solution —]. Then in the solution SO,-or Cl-ions are left free, 
and in the mercury + electrons, which may move to the new sepa- 
rating surface. The total number He ions required, is obviously that, 
corresponding with @ds electric units. But we saw in II, that the 
change of energy, accompanying the passing of de electric units, is 
(only (a) and (4) have to be added): 
ae de. (Vi—V,) de. 
a) 
When in consequence wds units pass, this quantity will amount to 
oge +a) de. 
2 € 
According to (2), we may write this: 
op 
Ogden rie ee oO 
Moreover for the formation of a new electric double-layer (mercury 
+, solution —) a (negative) electric energy vds (V.— V)) is required, viz. 
GRUB Ar Hea, Mtd Tor thie) wen Meee Ce) 
Adding (a), (6) and (¢), and representing the mecanical energy, which 
must counterbalance these changes, by 
yds, 
we get finally: 
=p ton, 
being always +, we have in the case we are treating of 
(mereury +, solution —): 
A= kw, 
and finally we get the equation 
dp 9 : 
y=~—0 = ko? 2 ie Suk ea Oe ERI 
