OSMOTIC PRESSURE AND VISCOSITY 



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replaced by powdered gelatin. This supports the idea that 

 the influence of electrolytes on the viscosity of gelatin solutions 

 is due to the influence of the electrolytes on the swelling of solid 

 submicroscopic particles of gel in the solution. 



The nature of the curves in Fig. 71 between pH 4.6 and 3.8 

 requires an explanation. The curves are here the lower the 



pH 1.4 1.6 1.8 ED 2.2 E4 6 2.6 3.0 3.2 3.4 3.6 3.8 4.0 42 4.4 4.6 



FIG. 71. The influence of replacing liquid by powdered gelatin on viscosity 

 is exactly the reverse as on osmotic pressure. The more the powdered particles 

 replace the liquid gelatin the higher the viscosity. 



more liquid gelatin is replaced by solid gelatin. This is due to 

 the fact that it was necessary to let the suspensions stand for at 

 least 1 hour to allow the particles of powdered gelatin to swell 

 before the viscosity measurements were made. During this 

 time the liquid gelatin at or near the isoelectric point increases 



