668 



REVERSAL BY TRIVALEXT CATIONS 



of Fig. 6 show that this is the case. It may be mentioned incidentally 

 that the initial rate of diffusion of water into solutions was greater 

 when the membranes had been treated with oxyhemoglobin than 

 when they had been treated with gelatin. We shall return to this 

 phenomenon in another connection. 



-t — ' 

 <t3 



O 



• 1 — I 



T^ 



O 



300 

 280 

 260 



^ 240 



220 

 200 



180 



Pi 160 



140 



HMHHHilllNMIIllMK 

 8192 4096 2048 1024 512 256 128 64 32 16 6 4 2 



Concentration of electrolytes 



Fig. 7. Showing that the attraction of salts with trivalent cations for water is 

 considerably greater than the attraction of acid (HCI) for water, although acids 

 are very efficient in making the membrane positive. 



