SO-CALLED 'BIOLOGICAL PROPERTIES OF MILK 117 



that the agglutinating and therefore the inhibitory effect could 

 be apparently restored by adding a drop of typhoid agglutinating 

 serum, as shown in the table on the previous page. 



The breaking up of the clumps was accomplished by drawing 

 the milk up and down a fine pipette pressed against the bottom of 

 the vessel. 



The milk was almost germ-free, and the samples after inoculation 

 were kept at 37 C. 



H The effect of agglutination was also shown by Bub, working 

 on colostrum. Bub obtained evidence of some inhibition upon 

 the ordinary flora of milk at a temperature of from i5-i8 C., 

 the action being less marked at 37 C. If the milk was well shaken 

 before plating for the bacterial count, no inhibition was detected, 

 although the count was higher in boiled milk than in raw. The 

 organisms used were B. Coli, B. Paratyphosus and B. Pyocyaneus. 



Other observations which have been carried out by Much, 

 Bartelli, Gutseit and Kleinschmidt are for the most part on similar 

 lines to those already considered and confirmatory of the results 

 already obtained. 



Bartelli believed that the inhibition was due to the gradual 

 development of acidity in the milk owing to the growth of the lactic 

 acid organisms. If the milk was kept cool during the period of 

 inhibition, then the acidity did not rise and no inhibition occurred. 



Sassenhagen carried out a number of experiments with the 

 colostrum and later milk of both cows and goats. He considers 

 that the results show bactericidal power in the milk, which is 

 more marked in colostrum than in later milk. The table 

 on p. 118 has been compiled from the results given by Sassen- 

 hagen, but the figures hardly bear out the claims for any marked 

 power for destroying bacteria. 



In some experiments, drops of a culture of B. Coli were added. 

 The milk was in all cases collected with aseptic precautions, and 

 in some of the work the milk was heated to inactivate the comple- 

 ment (which he showed was present in colostrum) in order to 

 eliminate the bactericidal effect. The figures obtained at four 

 hours after milking in the experiments with colostrum justify to 



