264 



PATHOGENIC BACTERIA IN MILK 



We may say, then, that in all cases of milk-borne epidemics 

 there is some local community of milk supply. 



(b) Incidence as regrards social position.— In not a few 



epidemics a particularly large measure of disease has fallen upon 

 persons in good social position. This, of course, is due to the fact 

 that such persons consume in one way or another more milk than 

 do the poorer classes. The poor take their milk only in small 

 quantities in tea, coffee, or cocoa. The middle and upper classes 

 consume in some households large quantities of milk, often in an 

 uncooked condition. Particularly is this so with regard to children. 

 Again, in such households, the opportunities for milk consump- 

 tion are numerous, sometimes as frequently as four times a day. 

 There is yet another condition characteristic in the milk consump- 

 tion of well-to-do people, and that is that in their households milk 

 is stored more than in the homes of the poor. The poor purchase 

 what little milk they require, and drink it at once. But in better- 

 class houses milk is set for cream to rise, or stored for the following 

 day, or put aside for various culinary purposes. Hence there is 

 more opportunity not only for exposure to poison, but for organ- 

 isms to multiply and form products in the milk. These are all 

 minor matters, but they distinctly affect the quantity of milk con- 

 sumed by different social classes. 



In Marylebone in 1872 an epidemic particularly affected the 

 wealthier classes, and the same occurred in a more marked degree 

 at Wimbledon in the sudden epidemic, referred to above, which 

 occurred there at Christmas time in 1886. In this case, fortunately, 

 a careful record was drawn up for the Local Sanitary authority 

 respecting the incidence of scarlet fever upon houses of certain 

 rental, with the following interesting result : — 



