JACQUES LOEB 



623 



dered gelatin particles of a definite size (going through a sieve with 

 mesh No. 30 but not through mesh No. 60) were rendered isoelectric 

 and then put into 200 cc. of various concentrations of KCl, LiCl, or 

 NaCl, made up in water containing 16 cc. of 0.1 n HCl at 20°C. 

 After 2 hours, during which the mixtures were stirred frequently, the 

 gelatin was separated from the supernatant liquid by filtration, and 

 after this the gelatin was melted and poured into special glass vessels, 



30 



25 



(0 



.i 



20 



15 



10 



.ri.MilMIIM.MM M M 

 2048 1(324 512 156 128 M 32 T© T T 



M. 

 ^ ^^#BlM4 5i2 ^fesMtltt'FTT 



Concentration of salts 



Fig. 2. Influence of LiCl, NaCl, and KCl on p.d. between solid particles of 

 gelatin chloride and surrounding liquid at pH 3.0. This influence is the same 

 for all three salts, suggesting that there exists only a depressing influence of the 

 anion but no opposite influence of the cation on this p.d. Abscissae are the 

 concentration of the salts; ordinates, observed p.d. 



and allowed to solidify in the vessels standing on ice for 1 hour. The 

 supernatant solution was also cooled in the same way. The p.d. be- 

 tween the solid gelatin and the supernatant liquid with which it was 

 in equiUbrium was then measured at a temperature of about 5°C. with 

 calomel electrodes and saturated solutions of KCl by a Compton 



