actions, and of the motion of the blood in them, which Galen
entertained, are not stated in a complete shape in any one of his
numerous works. But a careful collation of the various passages in which
these conceptions are expressed leaves no doubt upon my mind that
Galen's views respecting the structure of the organs concerned were, for
the most part, as accurate as the means of anatomical analysis at his
command permitted; and that he had exact and consistent, though by no
means equally just, notions of the actions of these organs and of the
movements of the blood.
Starting from the fundamental facts established by Erasistratus
respecting the structure of the heart and the working of its valves,
Galen's great service was the proof, by the only evidence which could
possess demonstrative value; namely, by that derived from experiments
upon living animals, that the arteries are as much full of blood during
life as the veins are, and that the left cavity of the heart, like the
right, is also filled with blood.
Galen, moreover, correctly asserted--though the means of investigation
at his disposition did not allow him to prove the fact--that the
ramifications of the vena arteriosa in the substance of the lungs
communicate with those of the arteria venosa, by direct, though
invisible, passages, which he terms anastomoses; and that, by means of
these communications, a certain portion of the blood of the right
ventricle of the heart passes through the lungs into the left ventricle.
In fact, Galen is quite clear as to the existence of a current of blood
through the lungs, though not of such a current as we now know traverses
them. For, while he believed that a part of the blood of the right
ventricle passes through the lungs, and even, as I shall show, described
at length the mechanical arrangements by which he supposes this passage
to be effected, he considered that the greater part of the blood in the
right ventricle passes directly, through certain pores in the septum,
into the left ventricle. And this was where Galen got upon his wrong
track, without which divergence a man of his scientific insight must
infallibly have discovered the true character of the pulmonary current,
and not improbably have been led to anticipate Harvey.
The best evidence of the state of knowledge respecting the motions of
the heart and blood in Harvey's time is afforded by those works of his
contemporaries which immediately preceded the publication of the
_Exercitatio Anatomica_, in 1628. And none can be more fitly cited for
this purpose than the _de Humani Corporis Fabrica_, Book X, of Adrian
van den Spieghel, who, like Harvey, was a pupil of Fabricius of
Aquapendente, and was of such distinguished ability and learning that
he succeeded his master in the chair of anatomy of Padua.
Van den Spieghel, or Spigelius, as he called himself in accordance with
the fashion of those days, died comparatively young, in 1625, and his
work was edited by his friend Daniel Bucretius, whose preface is dated
1627. The accounts of the heart and vessels, and of the motion of the
blood, which it contains, are full and clear; but, beyond matters of
detail, they go beyond Galen in only two points; and with respect to one
of these, Spigelius was in error.
The first point is the "pulmonary circulation," which is taught as
Realdus Columbus taught it nearly eighty years before. The second point
is, so far as I know, peculiar to Spigelius himself. He thinks that the
pulsation of the arteries has an effect in promoting the motion of the
blood contained in the veins which accompany them. Of the true course of
the blood as a whole, Spigelius has no more suspicion than had any other
physiologist of that age, except William Harvey; no rumor of whose
lectures at the College of Physicians, commenced six years before
Spieghel's death, was likely in those days of slow communication and in
the absence of periodical publications to have reached Italy.
Now, let anyone familiar with the pages of Spigelius take up Harvey's
treatise and mark the contrast.
The main object of the _Exercitatio_ is to put forth and demonstrate by
direct experimental and other accessory evidence a proposition which is
far from being hinted at either by Spigelius or by any of his
contemporaries or predecessors, and which is in diametrical
contradiction to the views respecting the course of the blood in the
veins which are expounded in their works.
From Galen to Spigelius, they one and all believed that the blood in the
vena cava and its branches flows from the main trunk toward the smaller
ramifications. There is a similar consensus in the doctrine that the
greater part, if not the whole, of the blood thus distributed by the
veins is derived from the liver; in which organ it is generated out of
the materials brought from the alimentary canal by means of the vena
portæ. And all Harvey's predecessors further agree in the belief that
only a small fraction of the total mass of the venous blood is conveyed
by the vena arteriosa to the lungs and passes by the arteria venosa to
the left ventricle, thence to be distributed over the body by the
arteries. Whether some portion of the refined and "pneumatic" arterial
blood traversed the anastomotic channels, the existence of which was
assumed, and so reached the systemic veins, or whether, on the contrary,
some portion of the venous blood made its entrance by the same passages
into the arteries, depended upon circumstances. Sometimes the current
might set one way, sometimes the other.
In direct opposition to these universally received views Harvey asserts
that the natural course of the blood in the veins is from the peripheral
ramifications toward the main trunk; that the mass of the blood to be
found in the veins at any moment was a short time before contained in
the arteries, and has simply flowed out of the latter into the veins;
and, finally, that the stream of blood which runs from the arteries into
the veins is constant, continuous, and rapid.
According to the view of Harvey's predecessors, the veins may be
compared to larger and smaller canals, fed by a spring which trickles
into the chief canals, whence the water flows to the rest. The heart and
lungs represent an engine set up in the principal canal to aerate some
of the water and scatter it all over the garden. Whether any of this
identical water came back to the engine or not would be a matter of
chance, and it would certainly have no sensible effect on the motion of
the water in the canals. In Harvey's conception of the matter, on the
other hand, the garden is watered by channels so arranged as to form a
circle, two points of which are occupied by propulsive engines. The
water is kept moving in a continual round within its channels, as much
entering the engines on one side as leaves them on the other; and the
motion of the water is entirely due to the engines.
It is in conceiving the motion of the blood, as a whole, to be circular,
and in ascribing that circular motion simply and solely to the
contractions of the walls of the heart, that Harvey is so completely
original. Before him, no one, that I can discover, had ever so much as
dreamed that a given portion of blood, contained, for example, in the
right ventricle of the heart, may, by the mere mechanical operation of
the working of that organ, be made to return to the very place from
which it started, after a long journey through the lungs and through
the body generally. And it should be remembered that it is to this
complete circuit of the blood alone that the term "circulation" can, in
strictness, be applied. It is of the essence of a circular motion that
that which moves returns to the place from whence it started. Hence the
discovery of the course of the blood from the right ventricle, through
the lungs, to the left ventricle was in no wise an anticipation of the
discovery of the circulation of the blood. For the blood which traverses
this part of its course no more describes a circle than the dweller in a
street who goes out of his own house and enters his next-door neighbor's
does so. Although there may be nothing but a party wall between him and
the room he has just left, it constitutes an efficient _défense de
circuler_. Thus, whatever they may have known of the so-called pulmonary
circulation, to say that Servetus or Columbus or Cæsalpinus deserves any
share of the credit which attaches to Harvey appears to me to be to
mistake the question at issue.
It must further be borne in mind that the determination of the true
course taken by the whole mass of the blood is only the most conspicuous
of the discoveries of Harvey; and that his analysis of the mechanism by
which the circulation is brought about is far in advance of anything
which had previously been published. For the first time it is shown that
the walls of the heart are active only during its systole or
contraction, and that the dilatation of the heart, in the diastole, is
purely passive. Whence it follows that the impulse by which the blood is
propelled is a _vis à tergo_, and that the blood is not drawn into the
heart by any such inhalent or suctorial action as not only the
predecessors, but many of the successors, of Harvey imagined it to
possess.
Harvey is no less original in his view of the cause of the arterial
pulse. In contravention of Galen and of all other anatomists up to his
own time, he affirms that the stretching of the arteries which gives
rise to the pulse is not due to the active dilatation of their walls,
but to their passive distention by the blood which is forced into them
at each beat of the heart; reversing Galen's dictum, he says that they
dilate as bags and not as bellows. This point of fundamental, practical
as well as theoretical, importance is most admirably demonstrated, not
only by experiment, but by pathological illustrations.
One of the weightiest arguments in Harvey's demonstration of the
circulation is based upon the comparison of the quantity of blood driven
out of the heart, at each beat, with the total quantity of blood in the
body. This, so far as I know, is the first time that quantitative
considerations are taken into account in the discussion of a
physiological problem. But one of the most striking differences between
ancient and modern physiological science, and one of the chief reasons
of the rapid progress of physiology in the last half-century, lies in
the introduction of exact quantitative determinations into physiological
experimentation and observation. The moderns use means of accurate
measurement which their forefathers neither possessed nor could
conceive, inasmuch as they are products of mechanical skill of the last
hundred years, and of the advance of branches of science which hardly
existed, even in germ, in the seventeenth century.
Having attained to a knowledge of the circulation of the blood, and of
the conditions on which its motion depends, Harvey had a ready deductive
solution for problems which had puzzled the older physiologists. Thus
the true significance of the valves in the veins became at once
apparent. Of no importance while the blood is flowing in its normal
course toward the heart, they at once oppose any accidental reversal of
its current which may arise from the pressure of adjacent muscles or the
like. And in like manner the swelling of the veins on the farther side
of the ligature, which so much troubled Cæsalpinus, became at once
intelligible as the natural result of the damming up of the returning
current.
In addition to the great positive results which are contained in the
treatise which Harvey modestly calls an _Exercise_ and which is, in
truth, not so long as many a pamphlet about some wholly insignificant
affair, its pages are characterized by such precision and simplicity of
statement, such force of reasoning, and such a clear comprehension of
the methods of inquiry and of the logic of physical science, that it
holds a unique rank among physiological monographs. Under this aspect, I
think I may fairly say that it has rarely been equalled and never
surpassed.
Such being the state of knowledge among his contemporaries, and such the
immense progress effected by Harvey, it is not wonderful that the
publication of the _Exercitatio_ produced a profound sensation. And the
best indirect evidence of the originality of its author, and of the
revolutionary character of his views, is to be found in the multiplicity
and the virulence of the attacks to which they were at once subjected.
Riolan, of Paris, had the greatest reputation of any anatomist of those
days, and he followed the course which is usually adopted by the men of
temporary notoriety toward those of enduring fame. According to Riolan,
Harvey's theory of the circulation was not true; and besides that, it
was not new; and, furthermore, he invented a mongrel doctrine of his
own, composed of the old views with as much of Harvey's as it was safe
to borrow, and tried therewith to fish credit for himself out of the
business. In fact, in wading through these forgotten controversies, I
felt myself quite at home. Substitute the name of Darwin for that of
Harvey, and the truth that history repeats itself will come home to the
dullest apprehension. It was said of the doctrine of the circulation of
the blood that nobody over forty could be got to adopt it; and I think I
remember a passage in the _Origin of Species_ to the effect that its
author expects to convert only young and flexible minds.
There is another curious point of resemblance in the fact that even
those who gave Harvey their general approbation and support sometimes
failed to apprehend the value of some of those parts of his doctrine
which are, indeed, merely auxiliary to the theory of the circulation,
but are only a little less important than it. Harvey's great friend and
champion, Sir George Ent, is in this case; and I am sorry to be obliged
to admit that Descartes falls under the same reprehension.
This great philosopher, mathematician, and physiologist, whose
conception of the phenomena of life as the results of mechanism is now
playing as great a part in physiological science as Harvey's own
discovery, never fails to speak with admiration, as Harvey gratefully
acknowledges, of the new theory of the circulation. And it is
astonishing--I had almost said humiliating--to find that even he is
unable to grasp Harvey's profoundly true view of the nature of the
systole and the diastole, or to see the force of the quantitative
argument. He adduces experimental evidence against the former position,
and is even further from the truth than Galen was, in his ideas of the
physical cause of the circulation.
Yet one more parallel with Darwin. In spite of all opposition, the
doctrine of the circulation propounded by Harvey was, in its essential
features, universally adopted within thirty years of the time of its
publication. Harvey's friend, Thomas Hobbes, remarked that he was the
only man, in his experience, who had the good-fortune to live long
enough to see a new doctrine accepted by the world at large.
It is, I believe, a cherished belief of Englishmen that Francis Bacon,
Viscount St. Albans and sometime lord chancellor of England, invented
that "inductive philosophy" of which they speak with almost as much
respect as they do of church and state; and that, if it had not been for
this "Baconian induction," science would never have extricated itself
from the miserable condition in which it was left by a set of
hair-splitting folk known as the ancient Greek philosophers. To be
accused of departing from the canons of the Baconian philosophy is
almost as bad as to be charged with forgetting your aspirates; it is
understood as a polite way of saying that you are an entirely absurd
speculator.
Now the _Novum Organon_ was published in 1620, while Harvey began to
teach the doctrine of the circulation, in his public lectures, in 1619.
Acquaintance with the Baconian induction, therefore, could not have had
much to do with Harvey's investigations. The _Exercitatio_, however, was
not published till 1628. Do we find in it any trace of the influence of
the _Novum Organon_? Absolutely none. So far from indulging in the
short-sighted and profoundly unscientific depreciation of the ancients
in which Bacon indulges, Harvey invariably speaks of them with that
respect which the faithful and intelligent study of the fragments of
their labors that remain to us must inspire in everyone who is
practically acquainted with the difficulties with which they had to
contend, and which they so often mastered. And, as to method, Harvey's
method is the method of Galen, the method of Realdus Columbus, the
method of Galileo, the method of every genuine worker in science either
in the past or the present. On the other hand, judged strictly by the
standard of his own time, Bacon's ignorance of the progress which
science had up to that time made is only to be equalled by his
insolence toward men in comparison with whom he was the merest sciolist.
Even when he had some hearsay knowledge of what has been done, his want
of acquaintance with the facts and his abnormal deficiency in what I may
call the scientific sense, prevent him from divining its importance.
Bacon could see nothing remarkable in the chief contributions to
science of Copernicus or of Kepler or of Galileo; Gilbert, his
fellow-countryman, is the subject of a sneer; while Galen is bespattered
with a shower of impertinences, which reach their climax in the epithets
"puppy" and "plague."
I venture to think that if Francis Bacon, instead of spending his time
in fabricating fine phrases about the advancement of learning, in order
to play, with due pomp, the part which he assigned to himself of
"trumpeter" of science, had put himself under Harvey's instructions, and
had applied his quick wit to discover and methodize the logical process
which underlaid the work of that consummate investigator, he would have
employed his time to better purpose, and, at any rate, would not have
deserved the just but sharp judgment which follows: "that his [Bacon's]
method is impracticable cannot I think be denied, if we reflect, not
only that it has never produced any result, but also that the process by
which scientific truths have been established cannot be so presented as
even to appear to be in accordance with it." I quote from one of Mr.
Ellis' contributions to the great work of Bacon's most learned,
competent, and impartial biographer, Mr. Spedding.
Few of Harvey's sayings are recorded, but Aubrey tells us that someone
having enlarged upon the merits of the Baconian philosophy in his
presence, "Yes," said Harvey, "he writes philosophy like a chancellor."
On which pithy reply diverse persons will put diverse interpretations.
The illumination of experience may possibly tempt a modern follower of
Harvey to expound the dark saying thus: "So this servile courtier, this
intriguing politician, this unscrupulous lawyer, this witty master of
phrases proposes to teach me my business in the intervals of his. I have
borne with Riolan; let me also be patient with him." At any rate, I have
no better reading to offer.
In the latter half of the sixteenth and the beginning of the seventeenth
centuries the future of physical science was safe enough in the hands
of Gilbert, Galileo, Harvey, Descartes, and the noble army of
investigators who flocked to their standard and followed up the advance
of their leaders. I do not believe that their wonderfully rapid progress
would have been one whit retarded if the _Novum Organon_ had never seen
the light; while, if Harvey's little _Exercise_ had been lost,
physiology would have stood still until another Harvey was born into the
world.
THE "DEFENESTRATION" AT PRAGUE
THE THIRTY YEARS' WAR
A.D. 1618
SAMUEL R. GARDINER CHARLES F. HORNE
As the last great struggle between the contending sects of
Europe for political as well as spiritual power the Thirty
Years' War was one of the most important conflicts of the
modern age. It was mainly carried on in the German states, but
during its later stages all the great European powers were
involved. The horrors of its battles and sieges have often been
painted.
Among the direct causes of the war--the great general cause
being the standing antagonism between Catholics and
Protestants--was a clause in the Peace of Augsburg (1555) which
remained a source of friction. It provided that any
ecclesiastical prince who became Protestant must surrender the
lands as well as the authority of his office. In many instances
this clause was disregarded by the Protestants, who from the
first felt it to be unjust. Until the accession of Rudolph II
(1576) as Emperor of the Holy Roman Empire, there was no
imperial intolerance, and Protestantism rapidly spread. But the
harsh dealings of Rudolph with the Protestants provoked
resentment. In 1607 Donauworth, a free Protestant city, was
seized by the Catholic Duke of Bavaria. Next year the German
Protestants formed the defensive Evangelical Union. Meanwhile
Rudolph's policy only reacted in favor of the Protestant
nobles. In 1611 his brother Matthias supplanted him as King of
Bohemia, and in 1612 Rudolph died and Matthias succeeded to the
imperial throne.
The outbreak of the Thirty Years' War followed upon a
revolution in Bohemia, which was precipitated by Rudolph's
attempt to evade the Royal Charter, extorted from him in 1609
by the estates. Its chief feature was a guarantee of freedom of
conscience to Bohemians so long as they adhered to certain
recognized creeds; but it also involved questions of authority
over lands with respect to their use for religious purposes.
The difficulties with the Royal Charter, which had led to
Rudolph's downfall in Bohemia, were left to confront Matthias.
SAMUEL R. GARDINER
Whether it would have been possible in those days for a Catholic king to
have kept a Protestant nation in working order we cannot say. At all
events Matthias did not give the experiment a fair trial. He did not,
indeed, attack the Royal Charter directly on the lands of the
aristocracy. But he did his best to undermine it on his own. The
Protestants of Braunau, on the lands of the Abbot of Braunau, and the
Protestants of Klostergrab, on the lands of the Archbishop of Prague,
built churches for themselves, the use of which was prohibited by the
abbot and the archbishop. A dispute immediately arose as to the rights
of ecclesiastical land-owners, and it was argued on the Protestant side
that their lands were technically crown lands, and that they had
therefore no right to close the churches. Matthias took the opposite
view.
On his own estates Matthias found means to evade the charter. He
appointed Catholic priests to Protestant churches, and allowed measures
to be taken to compel Protestants to attend the Catholic service. Yet
for a long time the Protestant nobility kept quiet. Matthias was old and
infirm, and when he died they would, as they supposed, have an
opportunity of choosing their next king, and it was generally believed
that the election would fall upon a Protestant. The only question was
whether the Elector Palatine or the Elector of Saxony would be chosen.
Suddenly in 1617 the Bohemian Diet was summoned. When the Estates of the
kingdom met they were told that it was a mistake to suppose that the
crown of Bohemia was elective. Evidence was produced that for some time
before the election of Matthias the Estates had acknowledged the throne
to be hereditary, and the precedent of Matthias was to be set aside as
occurring in revolutionary times. Intimidation was used to assist the
argument, and men in the confidence of the court whispered in the ears
of those who refused to be convinced that it was to be hoped that they
had at least two heads on their shoulders.