568 



digtiirbed, wliicli disliirbauce tbr u verv inert nietal will go so far 

 till (he electron coiu'eiilratioii of the nickel equilibrium in the electrolyte 

 has conformed to the electron concentration of the hydrogen equili- 

 brium, and has become almost equal to it. 



For the limiting case of an ideal inert metal this equality will 

 become perfect, as is also lecjuired by /'J becoming zero in this case. 



In a former discussion of these phenomena the neglect of the 

 Volta-etTect led on the other hand to the conclusion that the electro- 

 motive force of the circuit, in case of equal electron-concentrations 

 in the electrolyte of the two metal equilibria, would be zero 07ilt/ 

 in appi'oxim a tion. 



It will have become clear through what pi-ecedes that while up 

 to now the Volta-etFect has lieen neglected in the A,.Y-figure, it is 

 better to draw the experimental potential E (e.g. with respect to 

 hydrogen) as ordinate instead of the potential ditTerence metal-liquid ; 

 then the thus obtained A', A'-ligures are perfectly rigorous. They then 

 indicate that for the three-phase equilibrium the two electrodes 

 possess the same experimental [)0tential ; the difference between their 

 potential differences with (lie electrolyte then l)eing equal to the 

 Volta-etfect between the two metals. 



In this point the following equation then holds: 



_ 0,058 ('^^> l) _ 0,U58 (^^1) 



or 



so that from the ratio of the solubility-products the situation of the 

 coexisting electrolyte immediately follows. Though this has been 

 shown already before, this circumstance is once more pointed out 

 here, to make clear that equation (6) is of no use to us here, for 

 this equation gives for the three-phase equilibrium: 



0.058 K^;^ 0,058 A^^; 

 log = — log + lxm j^i 



"■ (-K) "• (K) 



In this form the equation contains, however, the unknown Volta- 

 etfect and the unknown saturation-concentiations, so that a calcu- 

 lation as above is not possible. 



Summajy. 

 By application of the more recent views on the electromotive 



