EoBERTON. — Milk as a Veliide of Disease. o79 



regard to the contamination of milk \vith the poison of scarlet 

 fever. It was suggested that cows sutfered from the disease 

 as well as man, and that an epidemic might arise from the 

 use of milk from cows affected with it. The question was 

 raised in consequence of a limited epidemic of the fever occur- 

 ring in London, evidently due to the supply of milk from a 

 certain farm at Hendon. It was proved that the milk must 

 have been infected before it left the farm. It seemed, how- 

 ever, for a long time that the infection could not have come 

 directly from a human source, and, as certain cows introduced 

 into the dairy about that time were suffering from a feverish 

 disease, investigations were set on foot to see if scarlet fever 

 and this feverish disease in the cows were not identical. Dr. 

 Klein, whom I have before mentioned, made experiments, and 

 found apparently the same germ in both scarlet-fever patients 

 and the diseased cows ; and, according to him, this germ, 

 whether obtained from a scarlet-fever patient or from a cow, 

 when inoculated into calves, produced in them, with only 

 slight differences, the original cow fever. This seemed con- 

 clusive, but later investigations threw some doubts on the 

 results of Klein's research. Another outbreak of the same 

 •cow fever occurred at Hendon and elsewhere in 1887-88, but 

 was accompanied by no outbreak of scarlet fever, although 

 the milk of the diseased cows was sold and used. The animals 

 which had originally In'ought the cow fever to Hendon came 

 from Derbyshire, and it was ascertained that other cows from 

 the sa.me district sold at the same time had developed the 

 same disease ; but, although their milk had also been sold, no 

 epidemic of scarlet fever had resulted. Finally it was shown 

 that after all there was a possible source of infection of the 

 milk through human agency. During one or two other epi- 

 demics of scarlet fever it w^as found that there was a feverish 

 disease prevalent among cows in the neighbourhood, but this 

 would appear to have been a mere coincidence. It has not 

 been satisfactorily proved that scarlet fever does attack the 

 cow, but it is very certain that it can readily be spread by the 

 agency of a milk-supply. The same is probably ti'ue with 

 regard to measles ; but I can find no notices of epidemics of 

 measles which have been traced to this source. 



Diphtheria epidemics traced to the milk-supply have always 

 been associated with an impure supply of water from the dairy 

 in which the epidemic originated. In 1879 an epidemic at 

 Leatherhead, in Surrey, affected thirty families almost simul- 

 taneously, and twenty-nine of these families had a supply from 

 one dairy-farm. The water in use at this dairy came from a 

 tank, and was decidedly impure from the presence of decaying 

 organic matter. It was pi-obably the means by which the 

 milk became contaminated. 



