396 



ION SERIES AND PROTEINS, ni 



solution; and the depressing action of the CI ion increases with its 

 concentration. Moreover, the increase of the viscosity by the H ions 

 stops as soon as the pH of the solution reaches about 3.0. 



When we repeat the same experiment with a gelatin solution of pH 

 3.0, the addition of NaCl immediately causes a drop also (Fig. 2) 



to 

 o 

 o 



o 



" ^ 4DSB 2048 1DZ4 512 256 128 64 32 16 8 4 2 ^^^ 



Concentration 



Fig. 2. The specific viscosity of 1 per cent solution of gelatin chloride of pH 

 3.0 is depressed almost equally by the CI ion of HCl as of NaCl. The augmenting 

 effect of the H ion in the case of HCl is no longer noticeable. 



