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Home Extracts. 
Pleuro-Pneumonia amongst Cattle. 
By George Waters, Jun., M.R.C.V.S., Com Exchange Hill, 
Cambridge. 
PRIZE ESSAY. 
[Continued from page 335.] 
The inflammation of the pleura leads to an exudation of fluid, 
one part of which settles to the lower part of the chest, in a liquid 
form, more or less sanguinolent and ropy ; another adheres to the 
side of the pleura, and forms layers, to which the term coagulable 
lymph is applied : in some instances those exudations lead to 
adhesions between contiguous pleurae. 
The effusion of fluid in the cavity of the chest must interfere 
with the conditions of the lung, especially if the latter be in a 
healthy state : in that case it will become compressed ; but if the 
lung be inflamed, then the degree of firmness, as well as volume 
which it acquires, enables it to resist the pressure of the fluid, so 
that the presence of the latter in large quantities must then lead 
to the dilatation of the sides of the chest. The cases described 
justify the supposition that the pleura is liable to be affected 
earlier than the lung. Thus, in the third case, the pleura of the 
posterior lobe was opaque and thickened as far as its base, whilst 
the corresponding parenchyma of the lung exhibited few, if any, 
signs of disease : a similar state existed on the opposite side, in 
which the pleura and lungs were both diseased at the spinal edge 
of the middle lobe, whilst at its free edge the pleura only was 
affected. 
The tendency on the part of the pleura to be first affected is not 
without practical importance. Commencing pleurisy may furnish 
the first untoward symptoms, and indicate the propriety of active 
treatment, to which the disease will at that period in all proba- 
bility be amenable. 
The appearance which the sub-pleural cellular tissue presents 
in this disease is not without interest. It differs from the layers 
of coagulated lymph adhering to the outer surface of the pleura, 
inasmuch as it is firm, indurated, and more or less beset with cells. 
In that respect it closely resembles the interlobular cellular tissue, 
and ought to be considered in association with the diseased state 
of the lung; but that it may be partly the means of communicating 
