700 EXPERIMENT STATION RECORD. 



5.71 per cent, became tuberculous after an average exposure of 135 days. During the 

 same time 42 guinea pigs were exposed in the mangers of the same cows, and of this 

 number 6, or 14.28 per cent, were infected. 



A series of experiments was also carried out on 19 hogs, which were fed in all 462^ 

 gal. of tuberculous milk during an average feeding period of 143 days. None of the 

 pigs became infected. 



Comparing intraabdominal injections of tuberculous milk with ingestion of the 

 same product, it was found that the latter method required 12,000 times as much 

 milk as the former to produce an infection. These experiments are believed to show 

 that while the milk of tuberculous cows is a dangerous product, the liability to 

 infection from it is much less than from other sources of infection. Attention is 

 called to the fact that not one of the 132 guinea pigs injected with milk from one of 

 the cows which was badly affected with tuberculosis developed the disease. 



Clinical and bacteriological diagnosis of bovine tuberculosis, J. Vexner- 

 holm (Svensk Vet. Tidshr., 10 (1905), No. 11, pp. 444-451). — Particular attention is 

 given in this review to a consideration of the investigations of Ostertag and his asso- 

 ciates on the means of diagnosing various forms of tuberculosis, especially mammary 

 tuberculosis. 



The tuberculin test for tuberculosis, D. E. Salmon ( U. S. Dept. Agr., Bur. 

 Anim. Lulus. Cirr. 79, pp. 14). — This circular is a reprint from the Yearbook of the 

 Department for 1901 (E. S. R., 14, p. 396). 



Vaccination against tuberculosis, Thomassex ( Tijdschr. Veeartsenijk., 33 (1905), 

 No. 3, pp. 151-162). — The literature relating to this subject is briefly discussed. 



The author experimented with young calves to determine suitable methods of 

 immunizing them against tuberculosis. For this purpose cultures of human tubercle 

 bacilli, serum from hyperimmunized cattle, tuberculin, and bovovaccine of von 

 Behring were tested. As a result of the author's experiments it is concluded that 

 active immunity toward tuberculosis may be brought about in young calves. 



The author recommends that calves should be vaccinated at the age of about six 

 weeks before exposure to tuberculosis and only after a negative result from tuber- 

 culin test. The use of human tubercle bacilli of low virulence is preferred to that of 

 other vaccines or serums. Special care is urged in pulverizing the bacilli in order to 

 prevent possible pulmonary lesions in the young calves. The degree of immunity is 

 not definitely determined. The author believes that the method will suffer from 

 certain practical difficulties when applied on a large scale. 



The development of tubercular mammitis, G. Moussu (Rec. M&d. VH., 83 

 (1905), No. 23, pp. 777-788, j)ls. 2, Jigs. 2).— Attention is called to the fact that the 

 large percentage of tuberculosis observed in hogs fed on dairy by-products around 

 creameries and cheese factories has been greatly reduced as the direct result of steril- 

 izing these products. 



The author insists that it is not sufficient to regard the milk merely from cows 

 affected with tuberculosis of the udder as infectious. From his own observations 

 combined with those of others he believes that the milk of all tuberculous cows 

 must be considered as dangerous. It is granted that frequently, perhaps in the 

 majority of cases, the milk of tuberculous cows in which the udder is not affected 

 does not contain enough tubercle bacilli to produce infection. The fact can not be 

 determined, however, from an external examination of the cow, and the milk is, 

 therefore, to be suspected. 



In order to prevent the distribution of tuberculosis by means of tuberculous milk, 

 it is recommended that all tuberculous cows be excluded from herds which furnish 

 milk for the public. On account of the difficulty of carrying out such measures at 

 once it is recommended that temporarily the milk of tuberculous cows be sterilized 

 or otherwise treated so as to destroy the tubercle bacillus before distributing for use. 



Contagious mammitis, G. Mayall ( Vet. Rec, 18 (1905), No. 910, p. 414).— In 



