Inflammation of the brain, the pleura, the
stomach, or a limb, produces its effect upon the
heart and circulation.
The difference of this influence in arachnitis and
pleuritis is imperceptible ; so is that of inflammation
of the substance of the brain, and of the
lung.
The effect of inflammation of the stomach and
bowels, indeed, is peculiar : the pulse is small ; the
capillary circulation is impaired.
On the other hand, gangrene of any organ, or
of a limb, impresses the heart in such a manner,
that its function is first singularly impaired and
then annihilated.
Every thing proves that the influence of injury
is similar, whether it be inflicted upon one organ
or another, or even upon a limb. The same deduction
of a general sympathy, and the same
absence of any physiological deduction as to the
functions of individual parts or organs, obtains.
CHAPTER V.
OF THE EFFECTS OF THE APPLICATION OF
IRRITANTS TO THE WEB OF THE FROG.
I h a v e always distrusted the experiments in
which irritating or stimulating substances have
been applied to the web of the frog, in order
to determine the question of the irritability of the
capillary vessels. This kind of experiment involves
too many causes of complication, to admit
of any conclusion being drawn from them, respecting
either the nature or function of the minute
and capillary vessels in health, or their modifications
in disease.
The first effect of applying an irritating substance
to the web of a frog, is the infliction of
fear and pain. Fear singularly arrests the flow
of blood. Pain alone would probably immediately
accelerate the circulation.
M 2