2l6 



PATHOGENIC BACTERIA IN MILK 



1 124 country milks were examined, of which 84 (or 7-4 per cent.) were 

 tuberculous. Nor does this difference hold only in respect to B. 

 tuberculosis. In the years 1900 and 1901, 509 samples of town 

 milk were examined for B. coli and B. enteritidis sporogenes (two 

 organisms associated with contaminated disease-producing milk) 

 with the result that 126 samples (or 24-7 per cent) contained B. 

 coli, and 30 samples out of the 509 (or 5-8 per cent.) contained B. 

 enteritidis sporogenes. During the same two years 491 samples of 

 country milks were similarly examined, with the result that 218 

 (or 44-4 per cent.) contained B. coli, and 47 (or 9-6 per cent.) 

 samples contained B. enteritidis sporogenes. It will be seen, there- 

 fore, that of all the milks examined in Liverpool, more than twice 

 the number of tuberculous samples were found in the country milks 

 than in the town milks, and nearly twice the number of contami- 

 nated samples, when judged by the standard of the presence of ^, coli 

 or B. enteritidis sporogenes. The table of results ^ is as follows : — 



* These returns and percentages are calculated on the total numbers of rail and town milks examined. 

 No account is taken of the comparatively few cases in which the test was incomplete. 



t In 1900 out of the total of 560 samples, B. coli occurred alone in 47 cases (0'8 %), B. enteritidis 

 sporogenes alone in 69 cases (10-5 %), and both organisms occurred together in 14 instances (2"5 %). 

 In 1901 out of the total of 5t56 samples, B. coli was found alone in 335 cases (59-1 %), B. enteritidis 

 sporogenes alone in 6 cases (I'O %), and the two organisms together in 7 cases (1-2 %). 



In an investigation into the distribution of B. coli cojnmunis 

 made by Harriette Chick in the Thompson-Yates Laboratory at 

 Liverpool, this bacillus was found in 17 out of 239 samples of new 

 milk. Its presence was explained by contamination occurring in 

 the cowsheds.^ Balfour Stewart carried out a parallel investiga- 



^ Reports of the Medical Officer of Health of the City of Liverpool, 1898- 

 1902. 



2 Report of Thompson-Yates Laboratories (Liverpool, 1900), vol. iii., part i., 

 p. 29. 



