PATHOLOGY. 291 



been produced by inoculation. From the fact of its appear- 

 ance in the great majority of cases in connection with some 

 other disease, its existence is frequently overlooked ; or if not 

 passed over, it is regarded as an individual idiosyncrasy in the 

 manifestation of the primary affection, from which, however, 

 there seems sufficient reason that it should be considered 

 separately. 



It is not every case of debilitating catarrhal or other disease 

 which develops or is followed by this special and depraved 

 condition ; nor can we with certainty predict which shall, save 

 in so far as these are the result of infection or contagion de- 

 veloped from cases which have exhibited similar complications. 

 I have observed that scarlatina has oftener been associated 

 with debilitating diseases occurring during the spring than at 

 other seasons of the year. 



Although local changes and alterations are largely concerned 

 in the visible and a^jpreciable manifestations of the disease, 

 there is little doubt that the entire system is invaded, and the 

 general functional activity much impaired ; that the numerous 

 local phenomena are merely manifestations of a marked con- 

 stitutional dyscrasia. 



It may be regarded as a general rule that pyrexial symptoms 

 precede the appearance of the local eruption ; also, as we 

 have already stated, that scarlatina in the horse is ordinarily 

 a sequel of some other disease. It will generally be found that 

 the fever of the primary affection has fairly declined ere that 

 of the eruption is developed ; this distinct intermittence I have 

 repeatedly noted. The eruption or markings occurring in the 

 skin and mucous membranes seem the diagnostic symptoms 

 of the disease ; and if there is any specific poison, it is probably 

 here and in this manner that it is expended. 



From the hairy covering and pigmented condition of the 

 horse's skin, any slight variation in colour is unobservable, 

 while the changes in the character of the eruption are also more 

 difficult to determine. Of this eruption there are several 

 forms. In the horse, we have little difficulty in observing that 

 it shows itself in at least two distinctive manners : the smooth 

 and the phlyctaenoid. In the smooth form, the skin, although 

 elevated somewhat above the natural level, exhibits no percep- 

 tible change of character, no roughness or moisture ; in the 



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