JACQUES LOEB 



673 



TABLE I. 

 Influence of Concentration of NaCl on pH Inside Minus pE Outside at Equilibrium. 



TABLE 11/ 

 Depressing Effect of NaCl on P.D. at Equilibrium. 



® The sign of the observed p.d. was apparently, but not in reahty, the reverse 

 of the sign of the calculated p.d. This was due to the difference in the arrange- 

 ment of the hydrogen electrodes in both cases. In the "observed" p.d. the mem- 

 brane (serving as a hydrogen electrode) was between the concentrated and dUute 

 HCl, while in the "calculated" values the p.d. was obtained from the poten- 

 tiometric determinations of the pH. In this latter case the two hydrogen elec- 

 trodes were separated by a concentrated and a dilute solution. The "observed" 

 P.D. was hence between two solutions of different concentrations while in the "cal- 

 culated" values we measured the p.d. between two electrodes. In our tables 

 the apparent (but not real) reversal of sign due to the difference in arrangement 

 of the hydrogen electrodes in the two cases is corrected. 



