288 MR. youatt’s veterinary lectures. • 
referrible to the infiltration of th'e blood through the gossamer 
membrane of the air-cells; we have not even a louder and dis- 
tincter murmur: perhaps there is no variation from the sound of 
health, or if there is any difference, the murmur is fainter ;—the 
pleural membrane is thickened, and its elasticity is impaired, 
and the sound is not so readily transmitted. There is some¬ 
times a slight rubbing sound, and especially towards the su¬ 
perior region of the chest, as if there was friction between the 
thickened and indurated membranes. 
Cough.—To this may be added, the different character of the 
cough, sore and painful enough in both, but in pneumonia gene¬ 
rally hard and full and frequent. In pleurisy it is not so frequent, 
faint, suppressed, cut short, and rarely attended by discharge 
from the nose. 
These are sufficient guides in the early stage of the disease, 
and when it is most of all of importance to distinguish the one 
from the other. 
Progress. —If, after a few days, the breathing becomes a little 
more natural, the inspiration is lengthened and regular, and the 
expiration, although still prolonged, is suffered to be completed— 
if the twitchings are less evident and less frequent—if the cough 
can be fully expressed—if the pulse softens, although it may not 
diminish in frequency, and if the animal begins to lie down, or 
walks about of his own accord, there is hope of recovery. But 
if the pulse quickens, and although it is smaller, yet possesses the 
wiry character of inflammation—if the gaze at the fianks,previous]y 
by starts, becomes fixed as well as anxious—and the difficulty 
of breathing continues (the difficulty of accomplishing it, al¬ 
though the efforts are oftener repeated)—if patches of sweat break 
out, and the animal gets restless, paws, shifts his posture every 
instant, is unable longer to stand, yet hesitates whether he shall 
lie down, determines on it again and again, but fears, and at 
length falls rather than lies down, a fatal termination is at hand. 
For some time before his death, the effusion and its extent are 
evident enough: he not only walks unwillingly, but on the 
slightest exercise his pulse is strangely accelerated ; the feeling 
of suffocation comes over him, and he stops all of a sudden, and 
looks wdld and trembles ; he immediately recovers himself, and 
proceeds. There is, also, when the effusion is confirmed, oedema 
of some external part, and that occasionally to a very great ex¬ 
tent. This is oftenest observed in the abdomen, the chest, and 
the point of the breast. 
Effusion .—The cause of death is that which is the result of 
inflammation of a serous membrane, effusion. The cavity of 
the chest is occupied by the exhaled fluid, compressing the lungs 
