222 



POTENTIAL DIFFERENCES AND ANOMALOUS OSMOSIS 



The question then arises: How can we account for this valency- 

 effect of the ion with the same sign of charge as that of the particle of 

 water? The answer seems to be that we are dealing here with diflFusion 

 potentials which are independent of the membrane. This was proved 



pH 18 20 22 2.4 26 2fl 3D 32 3.4 36 3.8 4D .42 4.4 4.6 4.8 50 



Fig. 5. Influence of neutral salts on the p.d. across collodion membranes not 

 treated with gelatin. Otherwise same experiment as in Fig. 3. Notice differ- 

 ence between curves in Figs. 5 and 3, revealing the share of the protein in the 

 origin of the p.d. 



in the following way. Two beakers were filled with identical solu- 

 tions of HNO3, the HNO3 solution in one of the beakers being dis- 

 solved in m/256 CeCls or CaCla or NaCl or Na2S04, while the HNO3 

 in the other was dissolved in pure water. The pH was identical in 



