HO MILK AND THE PUBLIC HEALTH chap. 



11 samples of milk from 102 dairies contained tubercle 

 bacilli (10'7 per cent). Hess ^ examined samples of New- 

 York raw market milk. Excluding cases in which the 

 guinea-pigs died without results being obtainable, out of 107 

 samples 17 (16 per cent) set up tuberculosis in the animals. 



In Germany very similar results have been obtained. 

 For example, Petri, in 1898, found 14 per cent of Berlin milk 

 containing tubercle bacilli, and Beck in 1900 found 30 '3 per 

 cent infected. la Leipzig, Eber, in 1908, found 10-5 per 

 cent positive. 



Butter. — The investigations of numerous workers have 

 proved that tubercle bacilli are not infrequently present in 

 butter. The proportion of samples in which they have been 

 found to be present has varied considerably in the different 

 investigations. For some of them, particularly the earlier 

 work, it is not clear that the lesions produced by the acid-fast 

 butter bacillus were in all cases clearly differentiated from 

 those produced by the tubercle bacillus ; but with due allow- 

 ance for this, it is evident that the proportion of butter 

 samples containing virulent tubercle bacilli is a high one. 



No English results are available to the writer, but the 

 following are a few examples out of many Continental ones. 



A number of examinations of Berlin butter have been 

 made from time to time. Obermilller, in 1897, examined 14 

 samples and found tubercle bacilli in all of them. Eabino- 

 witsch, in 1897, examined 30 Berlin butters and failed to 

 find tubercle bacilli in any of them. In the same year she 

 examined 50 samples of Philadelphia butter, all also with 

 negative results. In 1899, however, the same investigator, 

 out of 15 Berlin butters, found 2 to contain tubercle bacilli 

 (13'3 per cent). In 1898 Hermann and Morgenroth found 

 4 out of 13 Berlin butters to contain virulent tubercle bacilli 

 (30-7 per cent). 



In other towns similar results have been obtained. Thus 

 Eeitz, in 190G, found 8 out of 96 samples of Stuttgart butter 

 to contain tubercle bacilli (8'5 per cent). Both, in 1894, 

 found tubercle bacilli in 2 out of 20 samples of Zurich butter 

 (10 per cent), and Tobler, in 1901, found tubercle bacilli in 

 2 out of 12 samples of Zurich butter (16"7 per cent). Eber, 



^ Trans. 6th International Congress on Tttberculosis, 1908, iv. pt. ii. p. 523. 



