TUBERCULOSIS 323 



bacillus of bovine tuberculosis, and that in the majority 

 of these cases the disease is introduced through cows' 

 milk." 



The dung and other excreta of tuberculous animals 

 frequently contain the bacilli of the disease, and in a dried 

 form is found floating in the air of cowsheds, barns, 

 and other farm buildings. Infection among cattle is 

 accomplished through the inhalation of dust of the infected 

 premises or of bacilli coughed into the air by diseased 

 animals, and also through the feeding of calves with milk 

 containing the organisms. 



.In Denmark and some other countries the separated 

 milk sent back from creameries to the farms for the 

 feeding of calves and pigs must first be pasteurized, so 

 as to destroy any virulent bacteria in it ; without this 

 precaution the milk from infected cattle on one farm 

 may be carried to another which is free from the disease. 



Tuberculosis is spread among human beings chiefly, 

 perhaps, by organisms coughed into the air by con- 

 sumptives and the bacilli of dried sputum, which rise 

 with dust into the air and are breathed into the lungs. 

 Fliigge and other authorities consider that the disease is 

 conveyed to children mainly through the digestive tract 

 in milk and other food containing the bacteria, some 

 holding the view that tuberculosis of the lungs or 

 phthisis frequently arises from organisms entering the 

 system in this way. 



The tubercle bacillus gains an entrance into milk 

 chiefly from cattle with tuberculous udders, but infected 

 milk may be given by cattle in which the disease cannot 

 be detected in the milk glands. It also enters in the 

 form of cowshed or stable dust, consisting of particles of 

 dung and other excreta from diseased animals. Possibly 



