CLARIFICATION OF MILK. 159 



These substances which make up the slime will be subjected to individual 

 scrutiny as progress is made. 



Amount of Slime removed. 



The amount of slime removed by the clarifier depends upon many 

 factors, as may be guessed from its component parts. Besides the in- 

 fluence of the constituents of milk, temperature, acidity or age of milk, 

 individuality of the cow, the condition of the machine, the number of 

 revolutions of the bowl, and probably many other factors determine the 

 amount of slime within its total limitations or the amount which is possible 

 within a given amount of milk. Then, too, as clarification proceeds, the 

 character — perhaps more specifically and accurately the consistency — 

 of the slime changes, which is doubtless attributable to the mechanical 

 action of the clarifier. 



Determination of the Weight of Slime. 

 As a rule, in literature moist weight is employed to report the amount 

 of slime. If conditions were identical when clarifjdng, the clarifiers the 

 same, the amount of milk passed of the same measurement, then possibly 

 a fairly representative lot of determinations could be established. This 

 seems very difficult, however, as will be gathered later. Owing to this 

 fluctuation in the moisture content, it is essential that the moisture be 

 eliminated to constant weight before comparisons can be satisfactorily 

 made and a true interpretation of the amount estabhshed. For many 

 purposes this additional labor may be avoided and the moist weight will 

 serve. Accordingly, it was found desirable early in the work to establish 

 the variatiouo in the determinations of the amount of slime from different 

 sources, since difficulty was met in the interpretation of results when based 

 upon moist weight alone. The determinations furnished are based on 

 clarification of milk at the same temperature, the same mUk and the same 

 age of milk, the use of the same machine, the same number of revolu- 

 tions per minute, — in short, the same methods and procedures throughout. 

 It is therefore a test of methods and procedures, and has its very im- 

 portant bearing upon slitne determination. The weights are always re- 

 corded as moist or dry weight. 



