BULLETI]^ I^o. 187. 



DEPARTMENT OF MICROBIOLOGY. 



CLARIFICATION OF MILK. 



Part I . 



I. INTRODUCTION. 



The Significance of the Clakifier. 



The use of the clarifier has been an outgrowth of the employment of 

 the "separator" in an attempt to clarify or purify milk. Since the func- 

 tion of the "separator" is to remove the fat from milk, the addition of a 

 new function to this machine presented compUcations not easily overcome 

 in a single machine, for as improvement takes place in the primary purpose 

 of the separator, retrogression may be instituted in the secondary, as in 

 this case, — the clarification or purification of milk. The separation of 

 fat from milk is not desired in clarification, yet it is desirable to accomplish 

 what the separator also succeeds in doing in part, — the removal of for- 

 eign and unwholesome elements so far as this is possible. A single- 

 purposed machine is susceptible of higher development simply because 

 it does not have to compromise with other and foreign purposes. Ac- 

 cordingly, there is good reason, as a basis, for endeavoring to perfect a 

 machine wliich will perform the single function of clarification in its 

 highest degree. 



What is Clarification? 



It is the work of this comparatively new machine, known as a clarifier, 

 which has been subjected to careful study in this laboratory. Its func- 

 tion, not its mechanism, has been studied. 



Milk is poured into the machine from which it emerges as milk. In its 

 passage through it has lost that substance which adheres to the bowl of 

 the machine, — the slime. The problem before us, therefore, takes this 

 form : What is the slime, and in its removal from milk has it improved or 

 injured the milk? The fullest answer which can be given at this time is 

 the substance of this continued thesis. The categorical reply to this 

 question*cannot be given till the close of this laboratory's studies, which, 



