480 



460 



440 



420 



400 



380 



360 



340 



320 



300 

 C 

 .2 280 



JO 



jg. 260 

 ^ 240 

 O 220 

 200 



s 







180 



160 



140 



120 



100 



80 



60 



40 



20 



LOnC. O ^ 4056 2048 M 512 256 128 64 32 16 8 4 



pH 



42 4.05 3.9 38 3.7 33 3.4 3.3 31 



Fig. 5. Free osmosis. Upper curve, influence of AI2CI6 upon the rate of dif- 

 fusion of water when the collodion membrane has been treated with gelatin; 

 lower curve, influence of AhCU on rate of difiusion when the membrane has not 



been treated with gelatin. 



571 



