HARPER F. ZOLLER 



645 



The curve for sulfite is not presented because of the inaccurate pH 

 data. But a maximum viscosity was obtained, using the same time 

 interval as employed in the other data, in a region corresponding 

 to a pH of 6.4 to 6.6. What this may mean is difficult to interpret 

 with the meager data at hand. No attempt was made to remove 

 SO2 from the solutions before taking measurements. 



3.0 



26 



1¥ 



2% 



3.0 « 



o 



u 



IB .!2 



16 



t¥ 



tx 



V/5Cosity - pH Curves 



oi 

 Casein Solutions 



JVa^PGjf 



Na^SiOi 



4/diCC^ 



Na^ ^sCt 



NdF 



— -O/J 



/¥ 



pH- 



7 a 



Fig. 4. Viscosity-pH curves of casein dissolved in the various solvents. Anion 

 effect on the viscosity maximum. 



With sodium arsenate a precipitation was observed at the point 

 of maximum viscosity; the precipitate increasing in quantity with 

 the increasing pH. The hydrogen electrode potentials were very 

 steady. On the other hand sodium silicate solutions of casein gave 

 unsteady potentials, although they were somewhat more steady than 

 with sulfite. The pH values for sodium silicates as given are correct 

 within 0.1 pH. 



