DISEASE GERMS IN MILK 93 



herds and is becoming more and more wide-spread. Cream- 

 eries, skimming stations and cheese factories constitute potent 

 agents in such distribution. These central stations receive 

 milk from a wide territory and, having passed the milk 

 through the separator, return to the farmers the skim milk 

 from the creameries, or the whey from cheese factories. The 

 routine methods in running such stations never allow a farmer 

 to receive back his own skim milk, but he receives the equiv- 

 alent amount that chances to be ready for distribution at the 

 time he is ready to take it. The result is that the milk of any 

 tuberculous cattle in the district will in the course of time be 

 distributed through the whole territory. This will be followed 

 by the presence of tuberculosis among new herds, especially of 

 calves, and also by the development of this disease among swine 

 that are fed upon such products. These central stations are 

 without doubt one of the chief agents in distributing tuber- 

 culosis over the country. There is one remedy for this, and one 

 only. The milk from such creameries should be pasteurized 

 before it is returned to the farmer. In Denmark this is required 

 by law, and the farmers never take back to their farm milk 

 that has not been subjected to a heat supposedly sufficient to 

 destroy tuberculosis bacilli. This procedure has rarely been 

 adopted in this country, but until it is adopted no dairyman can 

 be safe from the danger of tuberculosis among his calves and 

 swine, so long as they are fed upon skim milk returned from 

 the creamery or cheese factory. 



Relation to Mankind. A phase of this subject of even more 

 general interest is the relation of the milk from tuberculous 

 cattle to man, and the very important question whether tuber- 

 culosis among mankind is not attributable to the use of milk 

 from tuberculous cattle. Over this question there has been in 

 the last 10 years much dispute, many differences of opinion 

 and a vast deal of experimenting. Out of the growing mass 

 of facts that has been accumulating during this period have 



