288 PATHOGENIC BACTERIA IN MILK 



families supplied with milk from this contaminated source " 

 (Villar). Nevertheless, not only did the cows show the same 

 symptoms as in the Hendon disease, but it was proved that the 

 affection was readily communicable to cows by the hands of the 

 milkers, and that calves sucking the diseased cows became 

 ill and suffered from an eruption on the skin of the nose and 

 mucous membrane of the mouth. 



Nor was this the only outbreak having certain parallel 

 characters with the Hendon outbreak. There was, for example, 

 the Wiltshire disease investigated by Crookshank,^ the Edinburgh 

 disease investigated by Woodhead and Cotterill, and other similar 

 outbreaks in various parts of the country. The Agricultural 

 Department declared that all these contagious eruptions were of 

 the nature of so-called cow-pox and that they were not causally 

 related to scarlet fever in man. Klein pointed out that in his 

 opinion the Hendon disease differed in certain essential characters 

 from cow-pox. It was more rapid in its course, the corium was 

 more infiltrated, the period of encrustation was of shorter dura- 

 tion, and the progress of healing was quicker. Inoculation of 

 calves gave, he held, different results ; and in the case of the 

 Hendon disease there was distinct visceral disease in the affected 

 cows. We need not pursue the matter further than to say that Dr 

 Klein continues to maintain that whether those other outbreaks 

 were or were not identical with the "Hendon disease" of 1885, 

 that specific disease was, in fact, scarlet fever of the cow and gave 

 rise to the outbreak of scarlet fever in man in the epidemic 

 occurring in North London in 1885-6. 



For our part we are of opinion that the exact origin of the 

 London epidemic at that time has not yet been, and now probably 

 never will be, demonstrated. Even at the present time the 

 specific micro-organism which is the causal agent of human scarlet 

 fever is not fully established or proved. That is to say, no micro- 

 organism has yet been isolated in human scarlet fever which fulfils 

 the postulates of Koch. Much less was this the case sixteen years 

 ago when bacteriological methods were less perfect than they are 

 even to-day. From this it follows that the vera causa was obscure, 

 and yet without this link it was impossible to complete the chain 

 of evidence by which it could be definitely known that any disease 

 of the cow was responsible for the epidemic. The probabilities 

 might be strong or weak, but proof was wanting. The inoculation 



* Report to Agricultural Department of Privy CoutkH, 1887 ; see also 

 Professor Crookshank's Bacteriology and Infective Diseases, 1896, pp. 265-282. 



