The Works of William Harvey M.D.: Translated from the Latin with a life of the authorHarvey, William
Science
The Works of William Harvey M.D.: Translated from the Latin with a life of the author
Harvey, William
Blood -- Circulation -- Early works to 1800; Embryology -- Early works to 1800; Physiology -- Early works to 1800
Caspar Bauhin and John Riolan,[85] most learned men and skilful
anatomists, inform us from their observations, that if we carefully
watch the movements of the heart in the vivisection of an animal, we
shall perceive four motions distinct in time and in place, two of which
are proper to the auricles, two to the ventricles. With all deference to
such authority I say, that there are four motions distinct in point of
place, but not of time; for the two auricles move together, and so also
do the two ventricles, in such wise that though the places be four, the
times are only two. And this occurs in the following manner:
There are, as it were, two motions going on together; one of the
auricles, another of the ventricles; these by no means taking place
simultaneously, but the motion of the auricles preceding, that of the
heart itself following; the motion appearing to begin from the auricles
and to extend to the ventricles. When all things are becoming languid,
and the heart is dying, as also in fishes and the colder blooded
animals, there is a short pause between these two motions, so that the
heart aroused, as it were, appears to respond to the motion, now more
quickly, now more tardily; and at length, and when near to death, it
ceases to respond by its proper motion, but seems, as it were, to nod
the head, and is so obscurely moved that it appears rather to give signs
of motion to the pulsating auricle, than actually to move. The heart,
therefore, ceases to pulsate sooner than the auricles, so that the
auricles have been said to outlive it, the left ventricle ceasing to
pulsate first of all; then its auricle, next the right ventricle; and,
finally, all the other parts being at rest and dead, as Galen long since
observed, the right auricle still continues to beat; life, therefore,
appears to linger longest in the right auricle. Whilst the heart is
gradually dying, it is sometimes seen to reply, after two or three
contractions of the auricles, roused as it were to action, and making a
single pulsation, slowly, unwillingly, and with an effort.
But this especially is to be noted, that after the heart has ceased to
beat, the auricles however still contracting, a finger placed upon the
ventricles perceives the several pulsations of the auricles, precisely
in the same way and for the same reason, as we have said, that the
pulses of the ventricles are felt in the arteries, to wit, the
distension produced by the jet of blood. And if at this time, the
auricles alone pulsating, the point of the heart be cut off with a pair
of scissors, you will perceive the blood flowing out upon each
contraction of the auricles. Whence it is manifest how the blood enters
the ventricles, not by any attraction or dilatation of the heart, but
thrown into them by the pulses of the auricles.
Public-domain text, read in full here on John Shaqi.
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