Recent Developments in Public Hygiene. xxix 



patients, he gave his experience of a public institution, in 

 which the milk was for years exposed daily to the risk 

 of infection, by being carried through wards containing 

 scarlet fever patients, without any appreciable effect upon 

 persons who afterwards drank it. The milk was sometimes 

 even further in danger of being contaminated by being 

 served out by a woman who was actuall}^ attending on 

 the patients, and yet it did not produce the disease. 

 All this, of course, is only negative evidence, and Dr. 

 Murphy's object was not so much to oppose the doctrine, 

 that milk thus contaminated may cause scarlatina, as to 

 enforce the need of careful examination of the cows them- 

 selves, whenever milk is suspected of being the medium of 

 conveying infection. Under any circumstances, nothing but 

 benefit to the public health can result from full inquiry into 

 all such disputed questions. The whole matter shows 

 further, how necessary it is to keep ourselves open to the 

 influence of fresh knowledge, and be ready, if necessary, to 

 amend even what we had come to look on as settled 

 doctrines. 



As regards the two diseases to which I have referred, the 

 main points about their infectivity and mode of spread, 

 remain untouched. In connection with typhoid, we have 

 to guard against impure water supply and insanitary 

 surroundings ; and in the case of scarlet fever, we must 

 trust to isolation and disinfection, on account of the intense 

 contagiousness of the disease. 



