199 
ON SOME OF THE DISEASES OF THE STOMACH 
AND INTESTINES OF THE HORSE AND 
OTHER ANIMALS. 
By Professor Brown, M.R.C.V.S. 
{^Continuedfromp, 68.)] 
Chronic Diarrhcea. 
Much difference of opinion seems to prevail as to the 
precise force of the expression chronic applied to disease, 
whether it properly refers to an impassive aflPection likely to 
be of long duration, or to a malady that has already con¬ 
tinued for a considerable period; whether, in short, a chronic 
disease may commence independently and at once as a specific 
derangement of a function or an organ; or whether it must 
have been existent for a certain time before it can be said to 
have acquired the right to the title. The original wmrd seems 
to sanction the idea of previous existence and duration, and 
doubtless the popular interpretation is founded upon this 
notion. It may, however, be objected that, at whatever stage 
a disease may become chronic, it must have a commencement, 
and that, consequent!}^, as far as time of duration is concerned, 
nothing definite is asserted; and further, as many affections 
called chronic present the same general features from the 
first, it would be impossible to state at w^hat precise period 
the word chronic would be applicable, whether after a week’s 
or a month’s or a year’s continuance; while, by applying the 
term only to a certain degree of disease, we leave open the 
question of duration, and preserve a constant relation between 
the three terms, acute, subacute, and chronic, applied to 
three degrees of force or activity of disease, w’hich they will 
express by comparison, as nearly as possible. 
This definition of the term chronic we propose to accept 
for the discussion of the question before us, and hence to 
speak of chronic diarrhoea as that form of the disease cha¬ 
racterised by the absence of those symptoms of activity 
■which indicate the acute or most active, and the subacute or 
intermediate. Chronic diarrhoea may arise from debility of the 
vessels and follicles of the mucous membrane, permitting a 
free exudation of fluid into the canal, and causing habitual 
