d through the lungs. The blood from the right side of the
heart, in getting to the left side of the heart, only performs a
half-circle--it does not perform a whole circle--it does not return
to the place from whence it started; and hence the discovery of the
so-called "pulmonary circulation" has nothing whatever to do with that
greater discovery which I shall point out to you by-and-by was made
by Harvey, and which is alone really entitled to the name of the
circulation of the blood.

If anybody wants to understand what Harvey's great desert really was,
I would suggest to him that he devote himself to a course of reading,
which I cannot promise shall be very entertaining, but which, in this
respect at any rate, will be highly instructive--namely, the works of
the anatomists of the latter part of the 16th century and the beginning
of the 17th century. If anybody will take the trouble to do that which
I have thought it my business to do, he will find that the doctrines
respecting the action of the heart and the motion of the blood which
were taught in every university in Europe, whether in Padua or in Paris,
were essentially those put forward by Galen, 'plus' the discovery of the
pulmonary course of the blood which had been made by Realdus Columbus.
In every chair of anatomy and physiology (which studies were not then
separated) in Europe, it was taught that the blood brought to the liver
by the portal vein, and carried out of the liver to the 'vena cava'
by the hepatic vein, is distributed from the right side of the heart,
through the other veins, to all parts of the body; that the blood of the
arteries takes a like course from the heart towards the periphery; and
that it is there, by means of the 'anastomoses', more or less mixed up
with the venous blood. It so happens, by a curious chance, that up to
the year 1625 there was at Padua, which was Harvey's own university, a
very distinguished professor, Spigelius, whose work is extant, and who
teaches exactly what I am now telling you. It is perfectly true
that, some time before, Harvey's master, Fabricius, had not only
re-discovered, but had drawn much attention to certain pouch-like
structures, which are called the valves of the veins, found in the
muscular parts of the body, all of which are directed towards the heart,
and consequently impede the flow of the blood in the opposite direction.
And you will find it stated by people who have not thought much about
the matter