276 PURPURA h.*:morrhagica. 



develojDment of the disease. By some it has been regarded 

 and spoken of as essentially a local affection, as a disease of 

 the cutaneous tissue ; this is clearly not correct, seeing that 

 during its progress we have evident and severe constitutional 

 disturbance manifested by disorder of nearly all the functions 

 of the animal body, while we find that with marvellously 

 trifling cutaneous manifestations there are not unfrequently 

 serious constitutional phenomena ; that the local changes bear 

 no adequate relation to the severity of the systemic disturb- 

 auQe. It is also, we are aware, most successfully combated not 

 by local remedies, but by the employment of constitutional 

 means, and is most liable to terminate fatally when the con- 

 stitutional character of the affection is overlooked or ignored. 

 By others it has been classed with the charbonous diseases, 

 and spoken of as a form of anthrax ; this at the present, and 

 with the knowledge Ave possess, seems also a wrong estimate of 

 its nature. 



Unlike anthrax in its varied forms, it does not appear 

 capable of propagation by infection or inoculation ; nor has 

 there yet been demonstrated to exist in the blood of animals 

 suffering from this disease the specific organisms of pure 

 anthrax. The local swellings, too, both as to character, mode 

 of development, and their relation to the termination of the 

 disease, are totally different in purpura from those of 

 anthrax. 



Peculiarly a disease of the horse rather than of our other 

 patients, it is chiefly but not exclusively met with as a sequel 

 of such exhausting febrile disorders as influenza, strangles, or 

 even common catarrh. Largely a disease of debility, it appears 

 to consist in a morbid condition of the blood and capillary 

 bloodvessels, from which there results a marked disposition to 

 effusion or extravasation of blood in connection with the skin 

 and mucous membranes. Although there may be doubts as to 

 the exact nature of the changes which occur in the earlier 

 stages of purpura, the most rational explanation of the pheno- 

 mena seems that which refers these to alterations in the con- 

 ditions, vital and chemical, of the blood, and to certain 

 structural changes of the capillary bloodvessels. 



We speak of it as referable to a morbid state of the blood 

 and bloodvessels ; still we arc inclined to believe that these 



