TUBERCULIN 



115 



animals in a market or slaughter-house. A con- 

 siderable number of errors at first were found 

 when I examined animals in slaughter-houses after 

 they had been conveyed there by rail, etc. Since 

 that, using it on animals in their own premises, I 

 have found that it is practically infallible. I have 

 notes of one particular case, where twenty-five 

 animals in one dairy were tested, and afterwards 

 all were killed. There was only one animal 

 which did not react, and it was the only animal not 

 found to be tuberculous when killed." (Professor 

 McFadyean.) 



Two instances of the validity of this test will 

 suffice. In 1899, it was applied to 270 cows on 

 some farms in Lancashire. Of these cows, 180 

 reacted to the test, 85 did not react, and 5 were 

 doubtful. Tuberculous disease was actually found, 

 when they were killed, in 175 out of the 180 = 97.2 

 per cent. {Lancet, 5th August 1899). In 1901, 

 Arloing and Courmont published a critical account 

 of the whole subject, and gave the following facts. 

 In 80 calves, which on examination after death were 

 found not tuberculous, the test was negative : in 70 

 older cattle, which were tuberculous, the test was 

 positive in every case but one, though the dilution 

 of the serum was 1 in io. # It would be easy to 

 add instances of the value of this test, for it is 

 practised far and wide over the world. 



* For references to this paper, and to evidence put forward 

 against the validity of the test, and for criticism of such 

 evidence, see Gould's Year-Book of Medicine and Surgery, 

 1902 (Philadelphia, W. B. Saunders & Company). 



