DEFINITION — NATURE. 153 



temporary character, and all internal fittings of Avood when 

 much worn or of little value, are much better destroyed by 

 burninc: than retained to be washed and disinfected. 



CHAPTER V. 



VARIOLA EQUINA — HORSE POX — CONSTITUTIONAL GREASE. 



Definition. — A specific, mild, continued, or intermittent fever, 

 having in addition an eruption appearing on the skin and 

 mucous surfaces, the result of the entrance into the system of a 

 specific and palpable animal poison, which after a period of 

 latency passes through the distinct and definite stages of fever, 

 papular, vesicular, and pustular erupjtion, to he folloived by 

 decline. 



Nature. — Variola or variolous fever, as occurring in the very 

 different species of animals which we know are sufferers from 

 it, from man downwards, although marked by much similarity 

 or even many points of identity, is yet characterized in its de- 

 velopment, its characters, and propagation in these several 

 species by many features which seem to stamp it as in its 

 essential nature specifically distinct in each. 



In none of our patients, save the sheep, has the appearance 

 of variola, even in an epizootic form, given us much cause for 

 alarm. While with respect to the relations which variola of 

 one animal bears to that of another, there seems even now in 

 our day, after much experimentation and the extensive record 

 of facts which exist, no very general agreement. 



By some the existence of a distinct variolous fever in the 

 horse has been denied ; and this is scarcely to be wondered at 

 when we consider that, unless in the most distinctl}^ marked 

 and pronounced form in which it is seen in that animal, the 

 eruptive affection, which is known by the name and classed as 

 equine variola, is in the horse, in the majority of cases, either 

 passed over without attracting observation, or is confounded 

 with an aphthous eruption, or with the irregularly recurring 

 skin affection, commonly recognised by the term ' grease.' 

 In this way, probably, has the fever, which really seems to 



