Variola : Pox. 385 



the coat stared, their feet were drawn together and the back was 

 arched. The disease was commuriicatedto the owner. This was 

 clearly an outbreak of aphthous fever, which invaded England in 

 that year, and was still an unknown disease to medical men. The 

 implication of the heifer which would not have been inoculated 

 with variola through the hands of the milker, and the salivation 

 which is unknown in cow pox, but points directly to the buccal 

 vesicles of foot and mouth disease, are conclusive on this point. 



Ceely, later, after many fruitless attempts to convey smallpox 

 to the cow, at last met with results which indicated cowpox, and 

 which he thereafter passed from cow to cow with the character- 

 istic cowpox eruption. 



Fletcher further reports the transmission, of smallpox through 

 the horse to the cow, and thence to the child in the form of cow- 

 pox. 



In 1836, Thiele, Kasan, S. Russia, inoculated some cows on 

 the udder with smallpox lymph, and conveyed the lymph of the 

 resulting vesicles back to man, and from man to man for seventy- 

 five generations of the virus without finding any variation from 

 the type of the true vaccine disease. He repeated the experi- 

 ment with equal success in 1838. 



Such experiments, made before the days of careful antiseptic, 

 or aseptic, laboratory methods, by men who were daily engaged 

 in making vaccinations, cannot be very implicitly relied on, yet 

 the success of Thiele in Central Asia, the early home of variola, 

 may indicate the possibility of a transition, under given eastern 

 conditions, which, to say the least, is exceedingly rare in West- 

 ern Europe or America. 



The experiments of Klein, conducted under modern methods, 

 are more conclusive, and seem to imply the possibility of small- 

 pox passing into cowpox, in the bovine system, under some not 

 yet clearly defined conditions. Until such conditions are sufii- 

 ciently well known, so that they can be controlled at will, no one 

 can be justified in attempting to produce lymph for vaccination 

 by simply passing smallpox virus through the system of the cow. 

 It seems important to note one or two instances of the evident 

 transmission of smallpox from man to man through the bovine 

 System. 



In i860, Martin inoculated variolous matter, from a man who 



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