378 



an electrolyte of the concentration :}\, and that the electrode is snr- 

 rounded with hydrogen of a pi-essure of 1 aim., then onr conclusion 

 from the preceding communication that namely the platinnm eqni- 

 librinm iii the liqnid is governed by the electron concentration of 

 the hydrogen equilibrium in the electrolyte, or in other words that 



A=0 



A 



Fig. 1. 



the platinum electrode becomes hydrogen electrode, has the follow- 

 ing meaning : 



It appears from the A, .f-fig. 1 that the potential ditference of the 

 hydrogen with respect to the electrolyte x, is indicated by point c', 

 lying on the metastable prolongation of ac. 



Now it follows, however, from the considerations given here that 

 platinum will present the same potential difference a,s hydrogen in 

 the experiment mentioned here, and that the electrolyte will, thei'e- 

 fore, not only be electromotively in equilibrium with hydrogen, but 

 also with platinum. This means therefore that c' does not only lie 

 on the prolongation of ac, but at the same time on a line that has 

 taken tlie place of be. The line he referred to the electrolytes which 

 coexist electromotively with platinum in internal equilibrium, whereas 

 we now have to do with a curve that indicates the electrolytes that 

 can coexist with a state of platinum disturbed in a base direction; 

 hence this cui-ve lies above be, and is here indicated by b'c'. 



