600 Tuberculosis. 



to Klimmer's reports about 10,000 cattle were treated successfully by this method 

 (strict prophylactic and hygienic measures, however, were always enforced — rearing 

 calves with pasteurized milk or the milk of healthy nurse cows, removal of all 

 cows with open tuberculosis, isolation of vaccinated animals as much as possible, 

 etc.). In the course of this work 43 vaccinated animals were destroyed and found 

 free from tuberculosis on post-mortem examination. Gloeckner also reports favorable 

 results from the vaccination of 23 cattle, four of which were slaughtered at a 

 later date, one of these a non-reactor before vaccination was found to be free 

 from tuberculosis, and the other three reactors at the time of vaccination, showed 

 post-mortem evidence of the curative effect of the treatment. 



On the other hand Eber is of the opinion that the good results obtained are 

 to be attributed to the simultaneous prophylactic and hygienic measures. Weber 

 & Titze hold the same opinion. The latter exposed two vaccinated and two 

 unvaceinated control calves to infection from a cow with pulmonary tuberculosis, 

 after three months all were slaughtered and found affected with tuberculosis in 

 approximately the same degree. These experimenters are inclined to regard the 

 bacilli contained in the avirulent vaccine as so called piscine tubercle bacilli or 

 reptilian bacilli. 



4. Immunization with the Products of Metabolism of Tubercle 

 Bacilli (Heymans' Method). Heymans introduces human or bovine 

 tubercle bacilli enclosed in the membrane of reeds under the skin of cattle, 

 assuming that the bacilli will continue to vegetate and diffuse their 

 products of metabolism through the membrane, whereupon they 

 pass into the circulation, and immunize the body of the animal 

 thus impregnated with them even exerting a curative effect upon 

 already existing tuberculous processes. In the effort to maintain an 

 effective degree of immunity by annual repetition of the immunizing 

 process it is found that the degree of sensitiveness to tuberculin is 

 gradually diminished and that 50 to 60% of the animals will cease 

 to react to the third test. With the aid of this method it is claimed 

 to be possible to exterminate tuberculosis without resort to other 

 hygienic measures, in 80% of the herds treated. In badly infected 

 herds, however, this is possible only with the aid of other prophylactic 

 measures. 



As to the possibilities of this method which has been applied to over 20,000 

 cattle in Belgium, thus far only Heymans' reports have been available. According 

 to these the percentage of reactors in the vaccinated herds has been considerably 

 reduced year after year. Thus, for example, of 18 herds comprising 188 cattle 

 tested in 1907, and retested in the two following years, the percentages of reactors 

 were 45.32% and 21%, respectively. Only 50% of the reactors of the first test 

 responding positively two years later at the third test. That the tuberculin test 

 retains its diagnostic value after the subjection of animals to this treatment is 

 evidenced by the fact that on post-mortem inspection more than 1,400 treated cattle, 

 which had given negative reactions to the test, were found free from tuberculosis. 



Experiments with 18 vaccinated and 13 control animals showed that vaccinated 

 animals possessed a higher degree of resistance to subcutaneous as well as to 

 intestinal infection than not vaccinated cattle. Moussu, however, found that four 

 cattle that had clay tubes containing cultures of tubercle bacilli imbedded in their 

 tissues for some time, were affected just like cattle not thus treated when subjected 

 to intravenous infection with virulent bacilli. The serum of similarly treated 

 experiment animals showed no evidence of possessing any immunizing properties. 

 However, animals vyith culture tubes of bacilli imbedded in their tissues will react 

 to the tuberculin test. After the bacilli have died off, or after their removal from 

 the body, the animals cease to react. 



Technic. of Immunization. In the first two methods discussed the virus 

 or vaccine is injected into the blood stream while in the third and fourth methods 

 it is applied subcutaneously. 



1. Behring's Method. The virus (bovo- vaccine) consists of cultures of 

 human tubercle bacilli of a certain strain dried in a vacuum. The powder-like 

 substance thus obtained is prepared for use in quantities sufficient for immediate 



