. r >* MAINE STATE COLLEGE 



THE FAT GLOBULES OF MILK. 



BY L. H. MERRILL. 



The size of the fat globules in milk has an undoubted influence 

 upon the completeness with which the cream separates. Prof. 

 Babcoek. in the Report of the N. Y. Expt. Station for 1835, 

 describes a method by means of which the relative number and size 

 of the globules in different samples of milk may be ascertained. 



Omitting details, the method is briefly this : Capillary tubes of 

 glass are filled with a very dilute sample of the milk, temporarily 

 mounted in glycerine and placed in a horizontal position until the 

 globules have risen to the upper sides of the tubes. The slide is 

 then placed upon the stage of a microscope, the internal diameter 

 of the tube measured bv an eye piece micrometer, and the num- 

 ber of globules in a given length of the tube counted. The results 

 of a number of observations are calculated for a tube of uniform 

 length and diameter. The figures thus obtained serve to show 

 the relative number of globules in a given quantity of the sample 

 The relative size of the globules may be obtained by dividing the 

 per cent, of fat in the milk by the number of globules. 



This method was applied in the examination of the milk of five 

 of the Station cows, representing three breeds, Holstein, Jersey 

 and Ayrshire. Samples of the whole and skimmed milk were 

 taken on four successive days. Considerable variation was 

 shown from day to day, yet the individual peculiarities were well 

 marked, as is shown in the following table, which gives the average 

 of the results for the four days. 



Relative Number and Size of Globules ts Milk. 



Relative number 



t 



Eelative size of 



of globules. 



Fat. 



globules. 



213 



3.75 



182 



89 



.70 



81 



293 



3.75 



130 



79 



.43 



55 



188 



3.32 



178 



75 



.47 



65 



138 



4.57 



332 



19 



.10 



54 



140 



5.29 



390 



24 



.18 



81 



Jansje, whole milk 



" skimmed milk 



Kancy Avondale, whole milk 



" " skimmed milk 

 Queen Linda, whole milk 



" " skimmed milk 



Agnes, whole milk , 



" skimmed milk , 



Ida, whole milk 



" skimmed milk 



As might have been expected, the larger globules have gone 

 into the cream, leaving only the smaller ones in the skimmed 

 milk. In no case do these average one-half the size of those in 

 the whole milk, and in the case of Agnes they are less than one- 

 sixth as large. It is noticeable, also, that the globules in the 

 milk of the two Jerseys, Agnes and Ida, are double the size of 

 those of the other breeds, a fact which must in large part account 

 for the readv creaming of this milk. 



