PUEPUEA H^EMOEEHAGICA. 155 



the condition in which human beings liable to purpura are 

 seen ; there is an excess of certain elements in the blood, and 

 it is in this respect that purpura differs from scurvy, which 

 is due to the want of certain essential nutritive principles, 

 or to defect in the assimilations of food under circumstances 

 which tend to reduce the animal's vital powers. The history 

 of purpura in the horse has yet to be written, inasmuch as we 

 need special inquiries into the constitution of food that 

 the affected animals have lived upon prior to their attack, 

 and we also need more details as to the condition of the ani- 

 mals themselves. As yet veterinarians have been unsuc- 

 cessful in treating cases of real or supposed purpura hsemor- 

 rhagica, and I am anxious that the sesquichloride of iron 

 should be continually tried, given in moderate doses twice 

 daily, in combination with the spirits of nitric ether. Small 

 and repeated doses of turpentine have been found useful, but 

 I would not recommend a remedy which I know to be dan- 

 gerous as usually administered to horses. 



Purpura haemorrhagica has been witnessed in cattle, swine, 

 and sheep, but in none so commonly, according to the reports 

 of practitioners, as in the horse. My belief is, that, of all 

 animals, swine are more subject to it, arid I trust we may 

 glean some further information to throw light on this hitherto 

 somewhat mysterious disease. 



MANGE, SCAB, OR ITCH IN THE LOWER ANIMALS. 

 SCABIES. 



Scabies is a skin disease of a purely local nature, due to 

 an insect which induces irritation, ulceration, suppuration, 

 and encrustation on the surface of the body generally. It is 

 a contagious disease, never originating spontaneously, and 

 requiring for its development the passage of the parasites or 



