196 



MASS.- EXPERIMENT STATION BULLETIN 187 



The results of counting the micro-organisms in sHme are therefore un- 

 satisfactory, yet it is evident that very large numbers are imbedded in it, 

 sufficient at times, so far as the tables are concerned, to overthrow the 

 counts obtained in milk before and after clarification. It is only through 

 the study of the micro-organisms in slime, and the suspension of specific 

 organisms which will be given later, that any adequate notion of what 

 occurs in this respect is obtained. 



For purposes of illustrating the operation of the clarifier in the action 

 on micro-organisms, the following table is furnished. Other than this 

 little significance is to be given to results shown. 



Table XXV. — Bacteria per Gram of Moist Slime in the Three Seeming 



Layers. 



Sample VI. 



Sample IX. 



Sample XII. 



Bottom 



Middle 



Top 



(Direct, 

 Plate, 

 f Direct, 

 I Plate, 

 f Direct, 

 1 Plate, 



30,000,000 

 1,500,000 



30,000,000 

 1,100,000 



30,000,000 

 7,000,000 



350,000,000 

 200,000,000 

 450,000,000 

 200,000,000 

 600,000,000 

 160,000,000 



50,000,000 

 24,000,000 

 45,000,000 

 12,000,000 

 42,000,000 

 118,000,000 



III. MILK. 



When milk is subjected to clarification slime is removed. What com- 

 poses slime and what its significance is has been considered in the forego- 

 ing discussion. Apparently the nutritional value of milk has not been 

 materially altered so far as can be determined at present; corpuscular 

 elements have been removed, suspended dirt has been eliminated, micro- 

 organisms have been thrown out in large numbers. These, however, 

 have been determined through the slime. It now remains to study the 

 modifications of milk itself, including, as it does under natural circum- 

 stances, all of these elements. 



Corpuscular Elements op Milk. 



The so-called leucocytes are very greatly reduced in numbers by clari- 

 fication. This will be established bj'- attached data. Whether this re- 

 moval has any particular meaning per se other than demonstrating the 

 efficiency of the clarifier under normal or abnormal conditions cannot be 

 stated positively in the light of our present knowledge. However, the large 

 numbers present in inflammatory processes of the udder have a significance 

 from the standpoint of toxic products and pathogenic micro-organisms, 

 and accordingly may be considered objectionable. The thought, too, 

 of enormous numbers existing in milk due to inflammation, whether 

 local or general, is reprehensible in the same way that visible dirt affects 

 the value. Nevertheless, in normal milk large numbers are found, but 



