170 



When we lead hydrogen through the electrolyte, of which the 

 concentration d\ lies on the lefthand of the point c, the potential of 

 he hydrogen-electrode is indicated by the line c' e' . In this mode 

 of procedure the nickel electrode gets in contact with gaseous 

 hydrogen, and in the boundary layer which is simultaneously in 

 contact with nickel and hydrogen, the electrolyte c will be formed 

 in consequence of the reaction : 



while electrons and nickel ions (and a few hydrogen ions) are 

 deposited on the metal. Tliis renders the metal baser superticially 

 and both the three-phase equilibrium dee and the point a rise. 



A- 



A=0 



t)A + 



Ni' 



Xi 



X 



Fig. 5- 



2H 



This disturbance in base direction continues till the concentration 

 of the electrolyte has become equal to that in the boundary layer. 



This is the case when a three-phase equilibrium has formed of 

 which the electrolyte possesses the concentration x^, hence at the 

 place where the curve he intersects the vertical which corresponds 

 with this concentration. As tig. 5 shows, this takes place in point c' 



