CHAP. I.] PERIODICAL PREVALENCE OF FEVER. 207 



may give one horse a cold, or affect his lungs, 

 singly applied to him, would, if applied to many, 

 in like manner affect the whole : this constitutes 

 epidemy, or the distemper, as we will continue to 

 term it, though a more refined scholar tells us to 

 say 'tis epizootic / Cloudy weather and cold easterly 

 night winds, when the weather is warm or murky by 

 day, is more likely to check the action of the lungs 

 or of the whole system, than when a cold season 

 has prepared the animals to withstand the influence 

 thereof. An epidemic prevails sometimes in autumn; 

 but, happen when it may, horses at grass acquire 

 it less often than those which are kept in, upon 

 hard food. 



Symptoms. — As just intimated, a cold, that har- 

 binger of so many other evils, is what marks the 

 epidemic in every case ; in addition to this, the ani- 

 mal will labour under the other symptoms of fever 

 before described, according to its actual state of 

 body at the time of attack. Thus, if the horse be 

 in full flesh and vigour, his veins quickly fill with 

 the stream of life, inflammation of the blood will 

 ensue, or rather, to speak more accurately, of the 

 vessels which contain it; hence, simple fever, or 

 fever of the whole system follows, as before de- 

 scribed, pp. 182 — 186; but, be he poor, with little 

 blood to receive inflammation, low fever is that 

 particular affection which now accompanies the 

 original cold or catarrh. 



Hence, we feel no hesitation in classing the epi- 

 demic — at least all those which have happened in 



