86 PRINCIPLES AND PRACTICE OF MILK HYGIENE 



non-clinical reactors and not a single sample produced 

 tuberculosis when in j ected into guinea pigs. Later, in con- 

 j unction with Brauer, 18 he made a thorough test of the 

 milk from 10 non-clinical reactors, inoculating guinea 

 pigs, and feeding guinea pigs, calves and pigs. Not one 

 of the experimental animals developed tuberculosis. 

 Some of the guinea pigs in the feeding experiment re- 

 ceived 66 grammes of milk daily for 5 months, or 33 times 

 their body weight; 10 calves received 7 to 12 litres each 

 day for 8 to 11 months and 20 pigs were given 1 to 6 

 litres daily for 4 months. O. Miiller made inoculation 

 tests on guinea pigs with the milk from 9 non-clinical 

 reactors, and Ascher with the milk from 7, and tubercle 

 bacilli were not demonstrated in a single case. Ostertag 

 contends that in those cases in which tubercle bacilli were 

 demonstrated in the milk from non-clinical reactors, the 

 milk was infected secondarily, and in support of this 

 view he points out that in some of the cases in which 

 tubercle bacilli were demonstrated in the milk no lesions 

 of tuberculosis could be found on postmortem, while in 

 other cases lesions of open tuberculosis were present. At 

 any rate, the evidence in its entirety indicates that the 

 milk of non-clinical reactors is much less likely to contain 

 tubercle than the milk of cows with tuberculous udders 

 or which show clinical symptoms of the disease in other 

 organs. 



Influence of Dilution. While these experimental re- 

 sults indicate very accurately the conditions under which 

 tuberculous cows contaminate milk, it must not be for- 

 gotten that they relate to the milk of individual cows 

 tested separately, while in practice the milk of tuber- 



18 Zeitschr. fur Fleisch u. Milchhy., p. 80, No. 4, vol. xxiv. 



