392 INFECTIVE DISEASES. 



six were they able to demonstrate the presence of tubercle bacilli in 

 the milk, and then only in small numbers. 



Hirschberger found in twenty cases of tuberculosis in cattle 

 that the milk of eleven was virulent to guinea-pigs. Three cows out 

 of nine in which the disease was restricted to the lungs gave infected 

 milk. On the other hand, Nocard inoculated milk from eleven 

 tuberculous cows, of which only one had diseased udder, and only 

 this one gave infective milk. Bang injected rabbits with milk from 

 twenty-one cases of tuberculosis, with the udders apparently normal, 

 and the milk was virulent in two. 



The author had two cases of udder tuberculosis under observation, 

 and as no experiments had at the time been made in this country 

 with milk known to contain tubercle bacilli, it was decided to study 

 the effect on rabbits, and test the results obtained by Bang. These 

 cases were both interesting and instructive, and may be referred to 

 in detail. 



One was a case of advanced general tubercnlosis. There was extreme 

 emaciation, general apathy, and a peculiar dull expression of countenance. 

 The skin was dry and harsh, the coat staring, and there was loss of hair 

 in patches about the face and neck. There was dulness on percussion 

 over a large area of the thorax, and the respirations were increased in 

 rapidity. There was also occasional cough and some diarrhoea. But the 

 most interesting condition was observed on examination of the udder. 

 The gland was swollen, especially posteriorly, and distinct induration 

 could be felt on examination. The deposit appeared to be more or less 

 limited to the posterior quarters. The cow evinced no pain during the 

 examination of the udder, not even on the application of firm pressure. 



The author took samples in test-tubes of the milk from all four teats ; 

 when freshly drawn, it differed noticeably from the normal secretion. It 

 was a thin, watery, turbid fluid with whitish flakes in suspension, but it 

 was not gelatinous or muco-purulent in character, and was free from any 

 markedly yellow colour. After being set aside in the laboratory for 

 some hours it separated into a layer of cream and a turbid liquid of a 

 yellowish tint, while at the bottom of the test-tube there was a whitish 

 flocculent deposit, especially in the samples from the posterior quarters. 



There were tubercle bacilli both in the cream and in the deposit. In 

 the cream they were only present in small numbers, and were detected, 

 therefore, only after careful search. But in the deposit they were readily 

 found, as in a cover-glass preparation there were sometimes four or five 

 in the field of the microscope. 



The method adopted for the examination of this deposit was as 

 follows : The whole of the liquid in the test-tube was carefully poured 

 off, and a trace of the sediment spread out on a cover-glass. This was 

 allowed to dry, and passed through the flame, and stained in hot Ziehl- 

 Neelsen solution in the usual manner. 



