JACQUES LOEB 



397 



while the addition of HCl no longer causes a rise but the drop com- 

 mences a little later than in the case of NaCl. 



When, however, we make the same experiment with a gelatin 

 solution of pH 2.5 (Fig. 3), we notice an immediate drop upon the 



2.6 

 Z5 

 2.4 

 2.3 

 2.2 

 ^ 2.1 



10 



o 

 o 



to 



• r— « 



> 



O 



CO 



1.9 

 1.8 

 1.7 

 L6 

 L5 

 1.4 

 1.3 

 L2 

 1.1 

 1.0 



" aSB 4D96 2048 M 512 256 I2S 64 32 16 "5 



Concentration 



Fig. 3. When the gelatin solution has a pH of 2.5, HCl and NaCl depress the 

 specific viscosity of the gelatin solution to the same degree. 



addition of HCl as well as in the case of the addition of NaCl, and the 

 curve for HCl coincides practically with that for NaCl, as our theory 

 demands. 



That the depression of the viscosity of gelatin chloride due to the 

 presence of a salt is exclusively determined by the anion of the salt 



