38 



may be e(|ual in size, but (liircieiil in stnicdii-e. There can, however, 

 l)e another difference besides, \iz. in electrical charge. In the [)reced- 

 ing' conuniinii'ivtion the niolecnle kinds M and M^ were assnmed, 

 and for simplicity's sake the circumstance that part of these molecules 

 are electrically charged also in the metal, was not mentioned. This 

 circumstance need not be taken into account, because the electrical 

 charge of the atom M 'm one ion J/2 ■) was put equal to that in 

 the oilier ion {M--). If it had then been our intention to indicate 

 the total equilibrium in the metal, we might have drawn up the 

 following scheme : 



2 M- -^i^B:^M,---\-io& (1) 



(2) ^it it (3) (I) 



1M ^ M, (4) 



from which follows that the system wonld then be pseudoquaternary. 

 B^or an explanation of the electromotive disturbances of the equi- 

 librium mentioned in the preceding communication, a consideration 

 of the equilibrium (1) or (4) sufficed. Then equation (4) was chosen 

 and 1M and M^ wei-e therefore called the pseudo components, 

 though of course we might as well have taken 2M-- -j- 'oO and 



Now it is clear that when in the metal ions of equal structure 

 occur, bnt of different value, the scheme of equilibrium can be as 

 follows. 



J/- + 2 ^->:^J/- + 36 (1) 

 M 



(2) ^ ,. ^ (3^ .... (II) 



Tlie system is theji pseudo ternary, but in most of the cases it 

 will be sufficient to consider the pseudo binary system, indicated by 

 equation (1), and assume M- -j- 2 and M-- -|- 3 Ö as pseudo 

 components. A similar equilibrium will have to be assumed, when 

 the metal can go in solution with different valency under different 

 circumstances. This case is probably of frequent occurrence. 



Of course the metal phase is already complex, when metal ions 

 occur by the side of uncharged molecules, but this complexity does 

 not suffice to explain the peculiar electi-omotiv^e behaviour of the 

 metals, whereas schemes I and II are competent to do so. 



In connection with the foregoing considerations it could be shown 

 that the unary electromotive equilibrium finds its proper place in 

 the A, X figure of a pseudo system, which can clearly appear under 

 certain circumstances, when we namely succeed in bringing the 

 metal out of the state of internal equilibiium. Thus it was e.g. shown 



