VS2 ANNUAL REPORT OF THE Off. Doc. 



disease. It is hoped, however, that more rapid progress may be 

 made bv the use of vaccinal ion. by the method that has been devel 

 oped by the experimental work of this Hoard. The need for the 

 repression of tub* rculosis is two-fold. In 'the first place, the disease 

 is a very widespread affection of cattle and destroys great quanti 

 ties of property every year. Jn this way, breeders are discouraged 

 in the keeping of high-priced animals and the improvement of the 

 average quality of the live stock of the State is retarded. In the 

 second place, tuberculosis is of importance with relation to public 

 health. This subject has been discussed considerably of late and, 

 believing it to be of interest, I shall briefly review some of the lead- 

 ing facts that have been brought forward and especially some of 

 those thai have been developed recently that throw light on this 

 question. 



This subject is one with regard to which the greatest possible 

 differences of opinion have prevailed. Is tuberculosis of cattle trans 

 missible to man and, if so, to what extent is the milk of tuberculous 

 cows harmful? 



In answer to these questions Koch has said: "I should estimate 

 the extent of infection by the milk and flesh of tuberculous cattle, 

 and by the butter made from their milk, as hardly greater than 

 that of hereditary transmission, and I therefore do not deem it 

 advisable to take any measures against it.'' On the other hand, 

 von Behring has recently said: "The infants' milk is the chief 

 source of tuberculosis infection.'' These are the extreme views on 

 this subject. 



Is it true that the milk of tuberculous cows is of so little import- 

 ance to public health that no action on this subject is necessary, 

 or is the truth, perhaps, to be found somewhere between these 

 extreme views? 



A dogmatic answer to these questions can be of no value. Th<' 

 situation is to be cleared up not by opinion, but by facts. It does 

 not seem so strange that such different views prevail in regard to 

 tuberculosis when we consider how recent is our knowledge of this 

 disease. While some exceptionally clear sighted individuals recog- 

 nized tuberculosis to be a contagious disease in olden times, it 

 was oot generally so considered, even by the most advanced medical 

 thinkers, until after the epoch making experiments of the French 

 investigator, Villemin, in 1805. These experiments proved that 

 tuberculosis may be transmitted by inoculation from animal to 

 animal and from man to animal, they demonstrated the infectious 

 nature of the disease and were accepted as proving the identity of 

 human and animal tuberculosis. This work was repeated and con- 

 firmed bv numerous pathologists in different countries and espe- 

 cially by Chauveau (1808), Gerlach (1809), Bollinger, Klebs and 

 Cohnheim. 



The unity of the different forms of tuberculosis of mammals was 

 regarded as fully proven when, in 1882, Koch discovered the tubercle 

 bacillus and established the fact that this germ is the cause of 

 tuberculosis and that there can be no tuberculosis without the 

 presence of the tubercle bacillus. This discovery placed the study 

 of tuberculosis on an entirely new plane and there was a general 

 agreement to the effect that tuberculosis of man and of the higher 

 animals is one disease until, in 1898, Theobald Smith discovered 



