168 



of the metal equilibrium must alwa3^s be equal to the eleotron- 

 couceutration which exists iu the liquid in conse(iueuc'e of the other 

 prevailing equilibria. 



In this case we may say, that the iiielal is really iu equilibrium 

 Willi the electrolyte. When the metal dissolves in an acid, or when 

 a metal is deposited, the just mentioned equality of electron-concen- 

 tration prevails oidy in the boundary layer between metal and 

 electrolyte, and ditFusion takes continually place in the boundary layer. 



The just mentioned equality of the indicated electron-concentrations 

 must, therefore, also exist when in the case mentioned just now the 

 metal nickel has got in equilibrium with the electrolyte. Of course 

 there are always some transformations required for this, but these 

 are soon over, and can, therefore, not give rise to a permanent 

 distm-bance, at least if the solution has been treed as much as 

 possible from air and hydrogen by boiling in vacuum. 



We have acted upon this principle, and, as was communicated in 

 the preceding paper by Mr. Lobry de Bruin and myself, by this 

 procedure the equilibrium-potential was found of nickel that contained 



