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DISEASES OF TIlE RESPlltATORY ORGANS. 
mulations of effete matters, and the organism wanting in 
tone to resist the influence of diseased action. In the 
excited state of the circulation the various organs, unable to 
do what was before required of them, are now further called 
upon ; the lungs particularly suffer, passive congestion takes 
place, inflammation supervenes, and exudation results. As 
the respiratory surface is lessened, the circulation and respi¬ 
ration become more laboured, the fever increases, critical 
diarrhoea occurs, adding to the exhaustion ; the animal suffers 
rapid prostration, and dies, not so much from the force of 
the attack, as from the want of power to resist it. 
During the time the patient has been suffering there has 
been complete loss of appetite, but generally considerable 
thirst; he has probably lain down frequently for some days, 
and then remained standing for long periods, or, as in many 
instances, persists in lying down, frequently up to the last. 
The fact, once accepted, of a horse standing constantly 
during an attack of lung disease, we presume to be a fact no 
longer in the mind of any practitioner of experience. Horses 
certainly, for years past, have been observed to lie doMn 
commonly enough in every phase of pulmonary disorder; 
the obstinate continuance in the standing posture is, in our 
experience, rather the exception than the rule. 
Tost-mortem .—We find a considerable portion of the lung- 
structure obstructed by accumulated blood, and also by 
exudation matter, and often large quantities of fibrin between 
the lobules,giving the appearance of pleuro-pneumonia as seen 
in the lungs of cattle. Sections examined microscopically 
show a remarkable diminution, of the number of air-vesicles; 
the red exudation, which is found in large patches, some¬ 
times surrounded by a layer of fibrin, consists of large gra¬ 
nular corpuscles, and smaller granules in abundance. Oc¬ 
casionally a few cavities are found containing a purulent- 
looking fluid; in this fluid, however, the corpuscles are not 
those of perfectly formed pus, not being acted upon by acetic 
acid in the same way, although, in other respects, the general 
resemblance to pus-cells is perfect. 
In many of these cases the liver has been found soft, 
light-coloured, and enlarged to twice its normal size, its cells 
under the microscope appearing filled with large fat-globules; 
this state of fatty degeneration has doubtless existed for 
some time prior to the attack, which was the immediate 
cause of death, and would ultimately have led to rupture 
and internal haemorrhage. The influence exercised by the 
diseased organ upon the nutritive functions must, of course, 
be considerable, although it cannot be denied that animals 
