ACUTE PLEURISY. SI 
tions are cut short. The breathing is also abdominal, the muscles of the flanks 
heaving, while the chest walls seem nearly fixed ; and in very severe attacks, in 
which the patients seem to be threatened with smothering, they assume the sit- 
ting position, with fore legs apart, which is characteristic of pneumonia. 
These are the most pronounced symptoms of the first stage of the disease. 
During the next, which begins with the effusion of serum into the pleural cavity, 
the evidences of pain are not so marked, the breathing is less rapid, and the inspi- 
rations are deeper, unless the quantity of fluid is great, when the symptoms are 
much the same as at first; while if it is small, the breathing seems quite natural 
as long as the animal is quiet and lying down, but quickens on exertion. 
A large effusion threatens suffocation, the signs of which cannot be mistaken. 
It also seriously interferes with circulation, and in consequence the lips and 
tongue become purplish, and the feet and legs more or less swollen, in the course 
of two or three days. 
It is never easy even for an expert to determine positively the presence of 
this disease. During the first stage the only purely diagnostic sign is a slight 
sound caused by the dry and roughened opposing surfaces of the pleura as they 
rub in inspiration. A trained ear at the chest might detect this sound in some 
instances, but only in a few; for it is too slight and short, ending almost as soon 
as it has commenced. 
As for a positive diagnosis during the second stage, one could scarcely be 
reached were the quantity of fluid small; but if very considerable, its presence 
might be determined by percussion, which is performed as follows: Press the 
palm and fingers of the left hand firmly against the side of the chest, and tap 
lightly on one finger with the second finger of the right hand, giving sharp, quick 
blows. If the sound resulting is dead and flat, like that heard when one per- 
forms this operation on his own thigh, it denotes an absence of air in the part 
of the chest beneath the finger; whereas were the conditions normal, — all within 
the suspected side of the chest healthy, — the sound emitted would be much 
like that heard in percussion of the top of a table. And the absence of air in 
the chest, or a considerable diminution of the usual amount, indicates either 
the presence of a fluid in the pleural cavity or solidification of the lung, as in 
pneumonia. 
Another means of diagnosis is auscultation or listening while the ear is firmly 
pressed against the chest. In health the respiratory sound is distinctly heard in 
this position ; but in pleurisy it is either unappreciable or only feeble, excepting 
in cases in which the quantity of fluid is sufficient to compress the lung so that 
air cannot enter it — when the sound heard is even louder than on the unaffected 
side, and is much like that appreciable when the ear is placed to the front of 
the neck of the sufferer. 
An evidence of the presence of a very large effusion is a bulging between 
the ribs. 
