( 571 ) 
where the higher sign relates to the descending branch, the lower 
sign to the ascending branch. This equation may be represented by 
ya t bb acy els ea # x. (8) 
of which we will determine the coefficients a, b and c. 
I have chosen to this purpose a series of experiments of SMrru !) 
with 1/;,-normal KCl as electrolyte. The concentration of the solved 
He, Cls is here exceedingly small, and the difference of potential between 
the solution and the mercury is for this “normal-electrode” accurately 
known (OsTWALD) *), namely: 
Ay = —0,616 Volts. 
The place, where @ (or A) becomes zero, may be determined without 
difficulty. For from A = Ay + #& follows, that if A = 0: 
E= —A, = 0,616 Volts. 
Now in the experiments of SMITH Z is expressed in such units 
that # = 500 corresponds to 0,102 Volts. The value 
0,616 Volts = 6,04 x 0,102 Volts 
corresponds therefore in the units of Smiry with 
E= 6,04 X 500 = 3020. 
V. For the calculation of the descending branch we have: there- 
fore to take into account only such values of H as are greater than 
3020. From this I calculated: 
0,6518 0,090 
= 29,766, b = Soyer ies 
GE a? De 
The following table shows, that these values represent the descending 
branch in fact with great accuracy. 
1) Zeitschr. f. Ph. Ch.'32, 460 and 467 (1900). 
*) Zeitschr, f. Ph. Ch. 35, 335 (1900). 
