118 MILK HYGIENE 



demic in a prison in Calcutta, with considerable cer- 

 tainty, to the distribution of the cholera bacilli through 

 the milk, and it was probable that the milk was already 

 infected before delivery. Graffky also reported an epi- 

 demic caused by infection through milk. 



In quite fresh milk, cholera bacilli appear to succumb 

 readily to its bactericidal action, but they increase 

 rapidly in older milk but are again checked and, at last, 

 killed, as the acidity increases. 



e. Tuberculosis. Tubercle bacilli may enter milk not 

 only from tuberculous cows and infected stables but also, 

 without doubt, from tuberculous people. Of course 

 there is no definite illustration for obvious reasons of 

 transmission of tuberculosis in this way ; but if one con- 

 siders what a quantity of tubercle bacilli may be ex- 

 creted daily by a consumptive, the possibility of such 

 transmission can scarcely be disputed, although the dan- 

 ger is considerably lessened by the fact that the number 

 of tubercle bacilli will not increase while the milk is kept. 

 It is justifiable, therefore, to forbid tuberculous people 

 working with market milk. 



/. Other diseases. It is stated in text books that there 

 are instances of the transmission of syphilis, and there 

 are reports in English journals of epidemics of sore 

 throat and of erysipelas which are said to have come 

 from infection through milk. In these latter cases, how- 

 ever, it is doubtful if the infectious material came di- 

 rectly from sick people, for the microbes concerned 

 (chiefly streptococci) may gain access to milk from other 

 sources. 



[As illustrations of such outbreaks of sore throat, 

 the three following cases are taken from among those 

 summarized by Swithinbank and Newman. 35 



;!5 Bacteriology of Milk. 



