290 
EDITORIAL OBSERVATIONS. 
appearance, without secretion — or, rather, with very sparing secre- 
tion, since it seldom or never happens there is none — denotes that 
the animal has died of that acute inflammation of the membrane 
which the French have called dry pleurisy , in contradistinction to 
the more common form of disease, which is accompanied by more 
or less serous effusion. 
A few hours’ sickness suffice for the development of inflamma- 
tion of the pleural membrane. But pleurisy is a disease of which 
horses rarely die without its being productive of fluid or solid 
matters, usually of both, in the cavity of the chest. Commonly, 
a short time after the inflammation has set in — in some cases, it 
would seem, almost simultaneous with its attack — the natural 
serous exhalation of the membrane augments and collects, either, 
as is usually the case, in the form of a citrine-coloured beauti- 
fully transparent fluid ; or, as sometimes happens, tinged with 
blood ; or the fluid may be turbid, and exhibit, when combined 
with solid effusion, flocculi of coagulable lymph floating in it. 
The effusion of coagulable lymph is a common accompaniment 
of the serous collection, presenting itself in the shape of plas- 
tic layers or masses upon the sides and surfaces of the lungs, 
with ragged extensions from one to the other, feebly uniting the 
opposed coated surfaces. Commonly, the effusion of “ water” 
precedes that of lymph ; though the effusions often to us appear 
to have had simultaneous origin. Acute pleurisy will run its 
course, under treatment, in about three days. It has been known 
to do so in one. Water, of the yellow limpid description, is 
usually found in some considerable quantity in three or four days. 
It has been known to have collected within the first twenty-four 
hours. Where we have nothing but th & post-mortem examination 
to guide our opinion, the consistence and character of the fluid 
will command our attention: the yellow, limpid fluid, or the same 
fluid mingled with the red particles of the blood, denoting the 
most recent date. And the same may be said of the solid 
effusion : coagulable lymph of a bright yellow colour, and soft 
gelatinous nature, loosely adhering to the membrane, honey-combed 
in its texture, and full of serous exudation, being demonstrative of 
its recent effusion. Beyond this it is extremely difficult, often 
indeed impossible, to assign any limits of date to the production of 
