COWPOX 89 



in butter, buttermilk and cheese, since it is not killed 

 by the treatment which milk undergoes in their 

 manufacture. 



This virus, the appearance of which is wholly un- 

 known (probably on account of its ultramicroscopic 

 size), is not particularly resistant. It has been proven 

 by experiments made during recent years in Germany 

 that the virus dies after 10 minutes' exposure at 70° C. 

 and by being heated to 100° C. for an instant. Experi- 

 ments made in Denmark seem to have shown that pas- 

 teurization at 80° to 85° C, as is done in our cooperative 

 creameries, is, without doubt, enough to destroy the 

 virus. 



c. Cowpox. This disease attacks particularly the 

 teats of the cow, and therefore it cannot be doubted that 

 during milking the virus held in the vesicles sometimes 

 falls into the milk. Since the vaccine virus is known to 

 be very potent, and since man is peculiarly susceptible 

 to it, it is evident that the disease is transmissible 

 through milk to man. But, while there are numerous 

 examples of direct infection on the hands and face of 

 the milker, there are only a few observations of an 

 infection through the use of such milk. The infrequency 

 of such cases may come partly from two conditions, 

 namely, that most persons are early immunized by com- 

 pulsory vaccination and that small children usually drink 

 the milk after it has been boiled or, at least, heated. 



Among the examples of this disease in children, which 

 have occurred through the use of milk from infected 

 cows and which are to be taken as unmistakable trans- 

 mission of the disease, the following observation by 

 Stern may be given: Cowpox broke out in a herd of 

 milch cows; a large number of children that had used 

 milk from this herd became affected with an eruption on 

 the face, which healed, leaving scars. 



