572 



CAUSE OF INFLUENCE OF IONS. H 



be greater than the positive charge of the membrane on the side of 

 pure water and water will be driven to the solution side. When, 

 however, the collodion membrane has not been treated with gelatin 

 it is negatively charged even in the presence of AI2CI6 and of acid, and 

 in the presence of the Al ions the CI ions cannot raise the negative 

 charge on the solution side of the membrane beyond that on the water 



25 

 EO 

 15 



10 

 5 



o 



I 



o 



-5 



8192 4096 2048 1D24 512 256 128 64 32 



Concentration 



Fig. 6. Electrical endosmose with the same two kinds of membrane. 



side. As a consequence in this case no other attraction of water by 

 the solution except that based on the gas pressure effect can be pro- 

 duced. If this view is correct, the curves of electro-endosmotic 

 transport of liquid through membranes treated and not treated with 

 gelatin must be similar to the curves of free osmosis in Fig. 5. Fig. 6 

 shows that this is the case. When identical solutions of AICI3 are 

 put into the collodion flask and into the beaker into which the collo- 

 dion flask is dipped, and when a p.d. is applied in the way described, 



