more before these men, finding themselves in the presence of a
master--finding that all their lives were occupied in attempting to
ascertain for themselves that which was familiar to him--I say it took
the best part of a hundred years before they could fairly see that their
business was not to follow him, but to follow his example--namely, to
look into the facts of nature for themselves, and to carry on, in his
spirit, the work he had begun. That was first done by Vesalius, one of
the greatest anatomists who ever lived; but his work does not specially
bear upon the question we are now concerned with. So far as regards
the motions of the heart and the course of the blood, the first man in
the Middle Ages, and indeed the only man who did anything which was of
real importance, was one Realdus Columbus, who was professor at Padua
in the year 1559, and published a great anatomical treatise. What
Realdus Columbus did was this; once more resorting to the method of
Galen, turning to the living animal, experimenting, he came upon new
facts, and one of these new facts was that there was not merely a
subordinate communication between the blood of the right side of the
heart and that of the left side of the heart, through the lungs, but
that there was a constant steady current of blood, setting through the
pulmonary artery on the right side, through the lungs, and back by the
pulmonary veins to the left side of the heart (Fig.3). Such was the
capital discovery and demonstration of Realdus Columbus. He is the man
who discovered what is loosely called the 'pulmonary circulation'; and
it really is quite absurd, in the face of the fact, that twenty years
afterwards we find Ambrose Pare, the great French surgeon, ascribing
this discovery to him as a matter of common notoriety, to find that
attempts are made to give the credit of it to other people. So far as
I know, this discovery of the course of the blood through the lungs,
which is called the pulmonary circulation, is the one step in real
advance that was made between the time of Galen and the time of