150 



after the polarizing current lias been broken for some time, and in 

 general is the weaker as the strength of the current is the smaller. 

 This hydrogen generation is, however, in no connection with the 

 other phenomena on anodic polarization, as the hydrogen generation 

 failed to appear in a number of experiments, though the anodic 

 behaviour was the same for the rest. 



The exj)lanation of the phenomena on cathodic polarization 

 presents one difliculty, viz. that through the cathodically separated 

 hydrogen, the metal in a solution of KCl is not activated. The metal, 

 indeed, gets a strongly negative potential, but the strength of the 

 current which the chromium anodically can bear, is not greater than 

 before the cathodic polarization. To explain this it should be assumed 

 that the cathodically developed hydrogen only remains at the metal 

 surface, and does not diffuse, or only very slightly, into the metal. 



Amsterdam, March 19 J 8. Chemical Laboratory of the 



Uiiiversili/. 



