322 Dumaresq : The Viscosity of Cream. 



SUMMARY. 



1. The main factors instrumental in varying the viscosity of 

 cream are acidity, temperature and fat content, and of these three 

 the first holds the most important place. 



2. Increase in acidity produces very little effect on viscosity of 

 cream, up to the " critical point," at which a sudden sharp rise in 

 viscosity occurs. 



3. The change in viscosity of separated milk at the degree of 

 acidity corresponding to the "critical acidity" of cream is very 

 slight — i.e., for separated milk there is no "critical acidity," 

 proving that this is a property of the fat globule, or rather of its 

 envelope. 



4. Increase in temperature of cream diminishes its viscosity, at 

 first rapidly, afterwards at a slower rate. 



5. The viscosity of cream is a quadratic function of the fat con- 

 tent, if the other factors remain constant. 



In conclusion, I take this opportunity of expressing my sincere 

 thanks to Dr. Rothera, at whose suggestion this work was under- 

 taken, for his continued interest and help. 



