VISCOSITY 



215 



rapidly heated to a temperature of 45 and then rapidly brought 

 to the temperature at which the change of viscosity of the solution 

 with time was to be observed. At definite intervals the viscosity 

 of the solution was measured. Figure 57 gives the result. At 



11.0 

 10.0 

 9.0 

 8.0 



to 



'53 6.0 



I 



*> 5.0 



4.0 



ao 



2.0 



OS 



tv 



chloride 



of 



oluLiorso 



5 10 15 20 25 30 35 40 45 50 55 60 



Time in minutes 



FIG. 57. Influence of temperature on the variation of viscosity of gelatin 

 solutions on standing. Below 35C. the viscosity of a 2 per cent gelatin chloride 

 solution of pH 2.7 no longer increases but diminishes on standing. 



15 the viscosity increased rapidly on standing; at 25 it increased 

 on standing but less rapidly; at 35 or above it diminished on 

 standing, the more rapidly the higher the temperature. The 



