JACQUES LOEB 



551 



are the quotients of the time of outflow of the casein solutions over 

 the time of outflow of distilled water through the same viscometer. 

 The time of outflow for distilled water was 60 seconds. We will, 

 for the sake of brevity, call this ratio specific viscosity. We see that 

 this specific viscosity does not rise above 1 as long as the pH is above 



^ 1-6 



N 



b 



o 

 o 

 (n 



CO 



o 

 u 

 to 



•? 





1.3 



1.2 



1.1 



1.0 



0.9 



pH 



4 



Fig. 3. Viscosity of 1 per cent solutions of casein chloride and casein phos- 

 phate. The curves are approximately identical. 



3.5. At a pH of 3.0 a sharp rise occurs, because the solubility of the 

 casein increases at this point considerably. With a further fall of 

 pH^the viscosity diminishes again. Fig. 3 shows that the viscosity 

 curves for casein chloride and casein phosphate are almost identical, 

 which was to be expected if the rules found for gelatin and crystalline 

 egg albumin are also true for casein. 



