72 CONJUNCTIVAL OPHTHALMIA. 



sition which its importance demands, and its destructive tendency 

 renders so desirable. 



In textures so different in nature and variously organized as 

 those composing the eye, inflammation naturally becomes modified 

 in its character, course, and consequences : in the conjunctive 

 membrane we become apprised of its presence through the ordi- 

 nary indications of redness and swelling, increased heat, and evi- 

 dent pain ; whereas, in the internal parts of the eye, too often does 

 it escape our observation until actual effusion or change of structure 

 has taken place. So long as it is confined to the conjunctiva, we 

 have no reason to believe that it anywise differs from inflammation 

 in other parts of the body ; but, no sooner has it implicated parts 

 composing the eyeball itself, than the same remedies no longer 

 exert the same influence over it. This circumstance has given 

 rise to a distinction of inflammations affecting the eye into that 

 which is common or simple in its nature, and that which is un- 

 common or specific in its character : in other words, into that kind 

 which we profess to understand, and that which, from the little 

 power we possess over it, we may fairly be said not to comprehend. 

 It is true that causation has much to do with the kind of inflamma- 

 tion that follows, — that peculiarity in the excitant appears an 

 essential part of the specific nature of the disease ; but, at the same 

 time, it is evident only certain parts can become the nidus for such 

 specific inflammation : we never see it confining its ravages to the 

 conjunctiva, although that membrane is in every case, in the acute 

 stages of the disease, more or less affected. 



Inflammation seizes the conjunctive membrane, primarily or 

 exclusively, from one of two kinds of causes : — either from changes 

 of temperature, or such influences as give rise to inflammation in 

 other mucous membranes, producing catarrhal affections ; or from 

 injury of some kind; and thus arises in the horse the disease 

 called 



CONJUNCTIVAL OPHTHALMIA. 



The anterior hemisphere of the globe of the eye, indeed every 

 tangible part of it, is covered by memhrana conjunctiva, ; and the 

 same membrane, by reflexion, becomes the linings of the upper and 



