36 SCIENCE AND THE STATE, ETC. 



brings them into contact with the diseased cattle, do suffer 

 from tubercular nodules in the skin, which contain tubercle 

 bacilli, undergo caseation, and disappear. I am convinced that 

 human infection with the bovine variety of tubercle can only 

 be quite exceptional : if it were not so, the inhabitants of 

 every country in the world in which bovine tuberculosis is 

 prevalent, would be decimated by tubercular disease. Tubercle 

 bacilli occur with frequency in milk, cream, butter, cheese, 

 and I have already given you some idea of the quantity of 

 meat derived from animals with more or less tuberculosis. 

 TUBERCULOSIS IN CHILDREN. 

 I would next draw your attention to the theory that 

 tuberculosis in children is necessarily due to infection from 

 the milk of tubercular cows. Those who advocate this view 

 appear to have entirely lost sight of the opportunities for 

 inoculation from a human source. Tuberculosis of the digestive 

 tract may result from swallowing sputum when there is con- 

 current disease of the lungs, and in many other ways. There 

 are obviously many paths by which a child may be infected 

 by the mouth with bacilli from a human source. A tubercular 

 mother may take little or no precaution in nursing her children, 

 and the habit of tasting food before giving it to an an infant 

 suggests a channel of infection. Various objects contaminated 

 by consumptive sputum may find their way to the mouth of a 

 child. London physicians who have had enormous experience 

 with patients suffering from consumption, of all ages, are by 

 no means ready to accept the milk theory. Sir Richard 

 Douglas Powell, one of the most cautious and scientific of 

 living phyicians, in his evidence before the Royal Commission, 

 stated that he had not met with any cases in his experience 

 which would connect consumption in man with the use of milk 

 and meat from tubercular animals. Dr. Goodhart, consulting 

 physician to the Evelina Hospital for Children, was of the 

 same opinion. I certainly am not prepared to attribute tuber- 

 culosis in children to a bovine origin, especially as the experi- 

 ments of Nocard and others have shown that when the milk 

 of the tubercular cow is mixed with the milk of healthy cows 

 it is no longer virulent to experimental animals. In order 

 to accept the theory that tuberculosis in children is due to 

 cow's milk, we should have to believe that in every instance 

 the milk supplied had been obtained direct from the udder of 

 a tubercular animal, without being mixed with the milk of 

 other cows. 



