( 564) 
Finally an accessory process takes place — and to this no suffi- 
++ 
cient attention has been paid as yet. As soon as a Hg,-ion has 
passed from the solution into the mercury, a superfluous SO,-ion (or 
Cl-ions) will go to the bordering layer, and in the mercury the + 
electron, which is liberated, will also move to the bordering layer. 
In the bordering layer therefore changes take place. Let ps be the 
so called capillary energy (s representing the surface). This quantity 
changes, when the SO4- (or Cl-)ions go from the interior to the 
bordering layer. For the transport of a quantity SO,, corresponding 
with de electric units, this change will be: 
0 (ps) 
eee cea OURS Neer 
In combining (a), (2) and (c), we get the following condition of 
equilibrium : 
(= Ma d = 
2 
2 4 (Vi Va) + = 0, 
or when we call uy — £4; = 49, and V;—V,=A, as we have 
already done: 
TN EERE Ee 
€ . SN 
where © = — represents the surface density of the charge of the 
8 
bordering layer. 
If we had made the supposition, that the mercury is negative, 
the solution positive (as is the case when the concentration of a 
++ 
Hgs-ions is exceedingly small), the electrons in the mercury at the 
berde, lis would have been negative, and in the solution 
positive He -ions would have occurred instead of the SO,- or Cl-ions. 
In that case we should have deduced the conditions of equilibrium, 
by imagining 2 Hg + positive electrons to pass from the mercury 
ao 
into the solution, where they would have formed Hg. The super- 
fluous negative electrons in the AGE would then go to the bordering 
layer, while in the solution the ee go thence. In this case 
we should have got: 
