566 



CAUSE OF INFLUENCE OF IONS. H 



was one electrode while the other electrode was a platinum wire 

 pushed through a glass tube into the collodion flask. The latter was 

 closed with a rubber stopper through which the glass tube with a 

 bore of 2 mm. diameter was pushed into the collodion flask. The 

 distance between the two electrodes was 7.0 cm. A p.d. of 15 volts 

 was applied and the current through the collodion membrane in- 

 creased slowly in intensity until it finally became fairly constant. 

 To accelerate this process a p.d. of 200 volts was used for 30 seconds 

 or a little longer, and then the p.d. was changed to 15 volts. This, 

 however, was done only in the case of the more dilute solutions. The 



I 

 1 



-*— > 

 o 



C 



§ n n M n M n n n 



^ 4096 2m 1024 512 256 125 64 32 



Concentration 



Fig. 2. Electrical endosmose. Effect of the same electrolytes as in Fig. 1 on 

 electrical endosmose. Inside and outside the collodion bag identical solutions. 

 Abscissae are the logarithms of concentrations of electrolyte in solution, ordi- 

 nates rise of level of liquid on the side of the cathode in 15 minutes. The influ- 

 ence of electrolytes on the rate of transport of water in electrical endosmose is 

 similar to that in free osmosis (Fig. 1), 



liquid rose in the glass tube when it contained the cathode, showing 

 that the watery phase was positively charged. The rise in level in the 

 glass tube was measured for 15 minutes (usually between 5 and 20 

 minutes after the commencement of the action of the current). 



The reader will notice that the amount of liquid transported by the 

 current rises at first with the increase in concentration of the solution 

 until the latter is about m/512 and that with a further increase in 



