776 
art AC: 
Ag == — K . (8), 
2D, +0, 7 
L 
and from (7) 
K 
BEG 
1 U sare L 
== AE } (9) 
de Ts edule K 
DD, 
K 
A is very small for silver cyanide, about 10, and when 
C, is not very large with respect to C, we may write: 
add 
C= cae BS gate eg en 
p as 
2d 
This equation gives, therefore, the current density below which 
no deposition of a precipitate on the anode takes place. 
It appears from it that this current density is the greater as the 
concentration .of the complex former is greater, the diffusion coeffi- 
cient greater, and d smaller. By means of vigorous stirring and 
increase of temperature we can work with a greater current density. 
For the rest the current density, at which the anode is covered 
with a precipitate, is about the same for all complex salts (for a 
same value of C), the coefficient of diffusion differing little. Of 
“K 
course this holds only when bk 5 is small. The values of A 
and /, have, therefore, no influence. When now bas is not 
very small, or C, great with respect to C,, equation (9) must be 
used instead of (10). The current density is now smaller, the 
numerator being smaller and the denominator greater than in (10). 
The potential, at which the deposition of Ag, (CN), begins, is 
found by substitution of (9) in equation (16) of the preceding paper: 
1 Y IN 
NAE 
Ee 40.058 log Kit 0.058: og 
- 
= 0.116 log ——— MOEREN 
b 
8 
f 
bs 
