92 THE COMMON SENSE OF THE MILK QUESTION 



Now, when this germ was thus identified its habits 

 could be observed. All over the world, physicians 

 and bacteriologists began to devote themselves to the 

 study of the tiny micro-organisms which ravage the 

 world with so much deadly effect. In 1890 Professor 

 Gustav Bang, of Copenhagen, demonstrated the 

 presence of the germ in cow's milk, showing that, 

 without knowing it, all persons who drink milk are 

 liable to swallow the germs of the most deadly of 

 human diseases, and that we feed such germs to our 

 babies when they are fed on cow's milk." Following 

 Bang, came Dr. German Sims Woodhead and Pro- 

 fessor Macfadyean, who not only found the tubercle 

 bacilli in milk, thus confirming Bang's discovery, but 

 also that a large number of cattle brought to the pub- 

 lic slaughter-houses of Edinburgh were tuberculous, 

 as were many of the milch cows, so that it was shown 

 that people without knowing it were eating the flesh 

 of tuberculous animals and drinking the milk from 

 them." It will be understood from this brief sketch 

 of the history of the tubercle bacillus how one of the 

 pathogenic varieties of bacteria came to be so inti- 

 mately and carefully studied. 



We do not need to consider in such detail the va- 

 rious stages in the study of the germs by which other 

 diseases, notably typhoid, scarlet fever, erysipelas, 

 diphtheria, and cholera are produced. Our illustra- 

 tion will suffice to explain why it is that men of science 



