174 APPLIED BACTEEIOLOGY 



siderable number of farmers is received twice a day, mixed 

 in a large tank, and passed through a centrifugal separator, 

 whereby the cream is collected. Thus, it is evident that if 

 the milk of one farmer was contaminated with typhoid, it 

 would be the means of the conveyance of the disease over 

 a large area. The only method of prevention of the spread 

 of infection by the contamination of milk would be proper 

 sterilisation, which would have to be systematically carried 

 out all the year round. 



Forty-eight epidemics of typhoid fever have been recorded 

 since 1882 as directly due to contaminated milk supplies 

 by Dr. E. Hart, in the pages of The British Medical Journal. 

 See the reprinted ' Keport on the Influence of Milk in 

 spreading Zymotic Diseases ' for the detailed reports of the 

 outbreaks. 



An epidemic of typhoid fever due to the milk-supply will 

 exhibit some or all of the following features : (1) The out- 

 break is sudden, and many of the attacks are simultaneous. 

 (2) A large proportion of the households attacked have a 

 common milk-supply. (3) The incidence of the disease 

 will be greatest on the principal consumers. 



Dr. E. Cautley (Local Government Board Report, 1896-7) 

 has recently investigated the behaviour of the typhoid 

 bacillus in milk. The following are his conclusions : 



The typhoid bacillus will live in milk under the conditions 

 that ordinarily prevail in a household. When this bacillus 

 has been artificially added in large amount to milk in the 

 condition in which it commonly reaches the consumer, the 

 presence of the microbe in the living state may be demon- 

 strated after the milk thus treated has been kept several 

 days. 



There is no indication from the above investigations that 

 this microbe is capable of multiplication under the condi- 

 tions in question. Judging from the results obtained, it is 



