28 Dairy Bacteriology. 



The responsibility of this defect should, however, not 

 be laid entirely upon the shoulders of the producer. The 

 factory operator should see that the refuse material does 

 not accumulate in the waste vats from day to day and be 

 transformed into a putrid mass. A dirty whey tank is 

 not an especially good object lesson to the patron to keep 

 his cans clean. 



It is possible that abnormal fermentations may thus be 

 disseminated from one farm to another in this way. 



Suppose there appears in the dairy of A an infectious 

 milk trouble, such as bitter milk. This milk is taken to the 

 factory and passes unnoticed into the general milk- supply. 

 The skim-milk from the separator is of course infected 

 with the germ, and if conditions favor its growth, the 

 whole lot soon becomes tainted. If this waste product is 

 returned to the different patrons in the same cans that 

 are used for the fresh milk, the probabilities are strongly 

 in favor of some of the cans being contaminated and thus 

 infecting the milk- supply of other patrons. If the organ- 

 ism is endowed with spores so that it can withstand un- 

 favorable treatment, this disease may spread from patron 

 to patron simply through the infection of the vessels that 

 are used for the transportation of the by-products. 



It would be possible to obviate any trouble arising from 

 this source if a separate receptacle was used for this pur- 

 pose, but the objection is frequently urged that this is 

 impractical, yet many of the more progressive factories 

 are following this practice with excellent results. 



35. Effect of steaming 1 milk-pails. Even where 

 utensils are in good condition and well cleaned, the germ 

 content of the milk may be reduced, and therefore, the 

 keeping quality enhanced by a brief steaming of the re- 

 ceiving cans. For this experiment 1 two cans were taken, 



1 Russell, nth Kept. Wis. Agr'l. Expt. Stat., p. 152, 1894. 



