MILK DANGERS AND REMEDIES 139 



turned is also mixed. Thus, in the event of the 

 milk from one farm being infected, not only is 

 the whole milk-supply of a particular dairy in- 

 fected, but, in returning the mixed skim milk 

 likewise infected in its proper proportion to the 

 different farmers, the virus is distributed over 

 several farms. So real is this danger, and such 

 unfortunate results have followed this practice of 

 returning mixed infected skim milk, that since 

 1894 the Prussian Government has issued special 

 orders for its disinfection by means of heat, in the 

 hope of coping with this difficulty. 



The longevity of the tubercle bacillus and its 

 remarkable vitality under all kinds of untoward 

 circumstances have not unnaturally added fresh 

 significance to this frequent discovery of its 

 presence in milk ; moreover, laboratory experi- 

 ments have shown that these germs can live for 

 upwards of one hundred and twenty days in 

 butter, and from sixty to seventy days in cheese. 

 It is not surprising, therefore, to find a Royal 

 Commission appointed in 1890 with the express 

 object of inquiring and reporting upon " What is 

 the effect, if any, of food derived from tubercu- 

 lous animals on human health ? " 



In the summary appended to the report we 

 read : " Tuberculous matter in milk is exception- 

 ally active in its operation upon animals fed either 



