THE TESTING OF MILK AND CREAM 



143 



PROPORTIONAL PARTS 



METHODS OF DETERMINING VISCOSITY OR CONSISTENCY 



(Babcock and Russell) (Fig. 37) 



In order to study the relative consistency of milk products, 

 it is necessary to have some measure that will indicate slight 

 differences in the substances 

 considered. For this pur- 

 pose different viscometers 

 have been employed, such 

 as noting the time required 

 for a given volume of liquid 

 to be discharged through 

 an opening of standard size, 

 as in a selected pipette. 



A more sensitive method 

 is based on measuring the 

 resistance to a moving body 

 immersed in a liquid. On 

 this principle several vis- 

 cometers have been de- 

 vised, but for our purpose a more simple method of com- 

 paring different samples is to be desired. The following 

 arrangement fulfills this purpose. 



The necessary apparatus consists of a piece of glass (pref- 

 erably plate or picture glass) about 12-15 inches square, and 

 a pipette with a small opening which enables one to obtain 



FIG. 37. Viscometer for determining 

 the consistency of cream. 



