ses', and that these
'anastomoses' existed not only in the body in general but also in the
lungs. In the next place, Galen maintained that all the veins of
the body arise from the liver; that they draw the blood thence and
distribute it over the body. People laugh at that notion now-a-days; but
if anybody will look at the facts he will see that it is a very probable
supposition. There is a great vein (hepatic vein--Fig. 1) which rises
out of the liver, and that vein goes straight into the 'vena cava' (Fig.
1) which passes to the heart, being there joined by the other veins
of the body. The liver itself is fed by a very large vein (portal
vein--Fig. 1), which comes from the alimentary canal. The way the
ancients looked at this matter was, that the food, after being received
into the alimentary canal, was then taken up by the branches of this
great vein, which are called the 'vena portae', just as the roots of a
plant suck up nourishment from the soil in which it lives; that then it
was carried to the liver, there to be what was called "concocted," which
was their phrase for its conversion into substances more fitted for
nutrition than previously existed in it. They then supposed that the
next thing to be done was to distribute this fluid through the body; and
Galen like his predecessors, imagined that the "concocted" blood, having
entered the great 'vena cava', was distributed by its ramifications all
over the body. So that, in his view (Fig. 2), the course of the blood
was from the intestine to the liver, and from the liver into the great
'vena cava', including what we now call the right auricle of the heart,
whence it was distributed by the branches of the veins. But the whole of
the blood was not thus disposed of. Part of the blood, it was supposed,
went through what we now call the pulmonary arteries (Fig. 1), and,
branching out there, gave exit to certain "fuliginous" products, and
at the same time took in from the air a something which Galen calls the
'pneuma'. He does not know anything about what we call oxygen; but it
is astonishing how very easy it would be to turn his language into the
equivalent of modern chemical theory. The old philosopher had so just
a suspicion of the real state of affairs that you could make use of his
language in many cases, if you substituted the word "oxygen," which we
now-a-days use, for the word 'pneuma'. Then he imagined that the blood,
further concocted or altered by contact with the