224 



POTENTIAL DIFFERENCES AND ANOMALOUS OSMOSIS 



of charge as that of the water "attract" the water with a force increas- 

 ing with the valency of the ion, while the Donnan effect seems to be 



pH 1.8 2D 22 24 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 42 44 4.6 4.8 5.0 5.2 5.4 



Fig. 7. Diffusion potentials between solutions of M/128cane sugar, m/256 

 NaCl, CaCl2, CeClj, and Na2S04 in various concentrations of HNOaand solutions 

 free from these salts but of the same concentrations of HNO3. The salt solutions 

 and the solutions free from salt had always the same pH. Abscissae are the pH; 

 ordinates, diffusion potentials. Attention is called to the resemblance between 

 the curves in Fig. 7 and those in Fig. 5. 



responsible for the fact that when the collodion membrane is impreg- 

 nated with a protein the rate of diffusion of the negatively charged 

 water is a minimum at the isoelectric point of the protein, increasing 



