264 TUBERCULOSIS. 



are soon overcome by the body resistance. Careful study has shown 

 that most people, by the time they have reached twenty-five years of 

 age, have not only been exposed to the disease, but have had mild 

 attacks, from which they have completely recovered. By building 

 up a proper physical vigor, an individual may successfully combat 

 these parasites. Plenty of wholesome, but not too rich food, 

 exercise, life out of doors as much as possible, sleeping in -rooms 

 with windows open in winter as well as in summer, and deep breath- 

 ing exercises, by means of which the lungs are filled with fresh air, 

 are the means by which such resistance can be developed and main- 

 tained. All of these conditions are usually within the reach of 

 everyone, so that there is no reason why a person who will, cannot 

 develop a high resistance against this dreaded disease. 



ARE BOVINE AND HUMAN TUBERCULOSIS THE 



SAME? 



Apart from its relation to the human being, the farmer is most 

 naturally interested in this disease, since it attacks his cattle. 

 Bovine tuberculosis is one of the most serious dangers, and threatens 

 the continuance of dairying. 



The significance of the question whether human and bovine 

 tuberculosis are identical is self-evident. If the two are the same, it 

 will follow that the disease may pass from animals to man; if they 

 are not identical such transmission is impossible. For some fifteen 

 years after the cause of the disease was discovered, no question was 

 raised as to their identity. Both diseases are produced by bacteria 

 that appear identical, and that they were the same was taken for 

 granted. In 1900, however, Prof. Koch raised the question whether 

 they were not distinct, and gave experiments to show that the 

 human bacillus does not produce the severe bovine tuberculosis 

 when inoculated into cattle. The question caused intense interest 

 and much discussion, and in spite of many experiments designed to 

 settle the matter, there is still some dispute. A fair summary of the 

 facts as they appear to the majority of bacteriologists to-day is as 

 follows: 



