The spinal marrow being removed in an eel, the
circulation became, at length, much enfeebled in
the pectoral fin. The part one inch and half below
the heart was crushed. The circulation in the
pectoral fin now ceased suddenly and entirely.
In an eel, in which the brain had been carefully
removed, and the spinal marrow destroyed, the
stomach was violently crushed with a hammer.
The heart which previously beat vigorously sixty
times in a minute, stopped suddenly and remained
motionless for many seconds. It then contracted ;
—after a long interval it contracted again, and
slowly and gradually recovered an action of considerable
frequency and vigor. No experiment can
more clearly demonstrate the effect of violence
inflicted upon the system generally. The experiment
is the more remarkable because the connection
and influence of the brain and spinal marrow
were entirely removed. The organic structures must
have been the medium through which the effect
of the violence was conveyed to the heart.
If the heart and circulation be viewed as independent
of the brain and spinal marrow, yet
impressible through them, this is equally true of
their relation to the stomach or a limb. But in fact
it is impossible to remove the brain and spinal
marrow at once without immediately impressing
the powers of the circulation, so that the motion
of the blood in the capillary vessels immediately
fails in the extreme parts of the system, and gradually,
in those placed nearer the heart. The
powers of the circulation are, on the other hand,
totally independent of any of the limbs. Yet they
may be suddenly destroyed through them.
Were we to draw any inference from these facts,
relative to the functions of these various parts, it
must be that all have the same function,—which
would be preposterous.
The physiological deduction which does flow
from them is that so much insisted upon by Hippocrates
himself, that every organ or part influences,
and is influenced by, every other ;—that there is a
prevailing sympathy.
2. Of the Influence of Inflammation and other
Diseases of various Organs, upon the Heart.
Similar deductions flow from observing the
effect of inflammation or other diseases of a part
or organ, upon the action of the heart. The effect
is one which differs in degree rather than in kind.