568 THE PRACTICE OF VETERINARY MEDICINE. 



the infection when it is upon the turn, the horses that 

 escaped the distemper being chiefly those that were kept in 

 constant strong exercise, or full aged old horses, many of 

 which were in no ways affected, although very much ex- 

 posed to it.' 



As will be seen by the above, the theory of contagion is 

 not one sprung into existence within the last few years, but, 

 on the contrary, influenza was, a century and a half ago, 

 asserted to be contagious by Wm. Gibson, at that time the 

 best authority and most eminent veterinary surgeon in Eng- 

 land, and who, a hundred years later, is frequently quoted 

 by Percivall, and referred to by that great writer in terms 

 of warmest praise. He further says ' I have known single 

 horses seized with the same symptoms at other times when 

 the distemper was neither infectious nor ei^idemical, and 

 these were always relieved with bleeding and evacuants, 

 especially with diuretics and diluters, giving them plenty of 

 water-gruel or white water.' Gibson's treatment, with 

 the exception of bleeding, was very similar to the course of 

 treatment pursued at the present time. 



White published a volume about the year 1830, in which 

 he says, speaking of influenza : — 'This disorder arises from 

 different causes, and is brought on in some cases by the 

 sudden application of cold and moisture when the body has 

 been heated and somewhat exhausted by excessive exercise ; 

 it arises also from a peculiar state of the atmosphere, and 

 then of course it is epidemic : it is of little importance in 

 this case to know whether it be infectious or not ; for if it 

 depends on a certain state of the atmosphere, that state 

 must prevail to a considerable extent.' 



Percivall very briefly alludes to the theory of contagion, 

 saying that he merely mentions it to state his disbelief. 



Woodroffe Hill, in his ' Bovine Medicine and Surgery, 

 states the disease to be highly contagious in cattle. 



