680 



DONNAN EQUILIBRIUM AND MEMBRANE POTENTIALS 



The same experiment was repeated with Na2S04 as a salt instead of 

 with NaCl. A comparison of Fig. 4 with Fig. 3 shows that Na2S04 

 depresses the sweUing of gelatin chloride more powerfully than NaCl 



60 



50 



40 





Q) 



30 



'OB 20 



CO 



p 



10 











M M M M M M M 



64 32 



n 



16 



8 



25 



20 



15 



10 



03 



1 — I 



o 



> 



O 



I 



to 



O 



8192 4096 2048 \02A 512 256 128 



Concentration of Na2S04 



Fig. 4. Similarity of depressing effect of Na2S04 on swelling and^p.D. of solid 

 gelatin chloride. 



and that it depresses also the p.d. more powerfully than is done by 

 NaCl.^Table VII gives the pH inside minus pH outside, and axom- 

 parison of the p.d. calculated and observed. The agreement is 

 again satisfactory. 



