itself. He prepared more accurate drawings of it than had been made
by any before him, making sections and dissections and examining its
valves (Fig. 30). Ultimately he succeeded in grasping the nature and
action of the valves at the root of the great arteries as they arise
from the heart, and he verified his view by remarkable experiments. He
proved that the valves allowed the blood to pass in only one direction,
and prevented its regurgitation. Yet Leonardo gives no complete or
clear description of the action of the heart. He could not emancipate
himself from the old idea of the passage of the blood from the right
ventricle through the septum into the left ventricle (Fig. 21), though
he sometimes seems doubtful about it.
[Illustration:
FIG. 30. DRAWING OF DISSECTION OF THE HEART by Leonardo da Vinci. The
modern names of some of the more important parts have been added.
]
It must be remembered that Leonardo did not publish his researches. It
is only recently that his note-books have become fully accessible. But
although Leonardo’s work remained in manuscript, it must not be assumed
that his views were wholly without effect on his contemporaries. At any
rate, soon after his time the questions that he had raised concerning
the heart and blood-vessels were attracting others and were generally
regarded as forming an important problem needing solution.
The task of writing an anatomical text-book based on direct
observation, to which Leonardo did but put his hand, was achieved by
one who was only four years old at the time when the great artist
died. The central place in the unfolding drama is occupied by Andreas
Vesalius of Brussels (1514-64). This extraordinary man studied first
at the University of Louvain and afterwards at Paris. Anatomical
instruction at these Universities had not improved much, if at all, on
that of the Middle Ages. Vesalius soon tired of hearing long passages
of Galen read out by the professor. He therefore resolved to go to
northern Italy, where newer methods were being practised. Padua was
the place of his choice. He immediately made his mark there, and was
himself appointed professor when only twenty-four years of age. He
established a scientific tradition at Padua which that University has
retained to this day.
No sooner was Vesalius settled at Padua than he applied himself with
unparalleled diligence to lecturing and research. Students crowded
to hear him (Fig. 31). To aid them he issued, in 1538, a short guide
to anatomy and physiology. An examination of this shows that his
physiological views were still those of Galen and Aristotle. After its
issue Vesalius found that Galen and Aristotle were by no means always
to be trusted. The realization of this led him constantly to doubt any
statement by them. His scepticism was sometimes excessive, but it led
him to put every statement made by his predecessors to the test of
experience. This gives his later work an epoch-making value.
[Illustration: FIG. 31. TITLE-PAGE of the work _On the Fabric of the
Human Body_, by Vesalius, published in 1543.
It shows a dissection scene at Padua. In the center stands Vesalius
dissecting a female body. At the head of the table stands an
articulated skeleton. At its foot are dissecting instruments. Eager
students throng around. In the foreground attendants are squabbling.
On one side an attendant holds a monkey, one on the other a dog, for
Vesalius had often to resort to animal in lieu of human anatomy. Shut
off by a bar are members of the lay public. Gallants, grey-bearded
scholars, monks, and an enthusiastic bookworm may be discerned among
them. Other observers crowd in from every vantage point, even from
the windows in the roof. The naked man to the left has been used by
Vesalius to demonstrate the surface markings of the underlying organs.
The whole scene is busy and vigorous in the extreme. It should be
contrasted with the academic calm of Fig. 28 drawn fifty years earlier.
]
During the next four years Vesalius had ampler opportunities to
dissect than he had yet encountered. He devoted a fiery energy to the
preparation of his great work. _The Fabric_ (that is ‘workings’,
compare German ‘Fabrik’) _of the Human Body_ was printed in 1543, a
magnificent and beautifully illustrated volume. It is a landmark in
the History of Science, and a wonderfully full record of a prodigious
number of accurately recorded discoveries and investigations made by a
single observer.
The masterpiece of Vesalius is not only the foundation of modern
Medicine as a science, but the first great positive achievement of
Science itself in modern times. As such it ranks with another work that
appeared in the same year, the treatise of Nicholas Copernicus, _On the
Revolutions of the Celestial Spheres_. The work of Copernicus removed
the Earth from the center of the Universe; that of Vesalius revealed
the real structure of man’s body. Between the two they destroyed for
ever the medieval theories on the subjects of which they treat. But
the work of Copernicus is one of close and subtle reasoning, still
retaining many medieval elements, and is hardly a great exposition
of what we now call the ‘Experimental Method’. The work of Vesalius
far more nearly resembles a modern scientific monograph than does the
treatise of Copernicus.
The achievement of Vesalius was very well received by the scientific
world. Nevertheless, soon after its publication, Vesalius resigned
his professorship to take up the position of a court physician to the
Emperor Charles V, the great monarch of the age. He was then only
twenty-nine years old, but his scientific career was closed.
The edition of the _Fabric_ was soon exhausted, and the demand for
more copies was met by imitations of the work by other hands. At last,
in 1555, Vesalius was induced to issue a second edition. This contains
certain changes in point of view that are important for the subsequent
development of physiology. Vesalius now no longer merely hints his
doubts as to the character of Galen’s physiology; he openly asserts
that he is unable to verify its fundamental bases.
We may take a single instance of this new outspokenness. In his
description of the septum of the heart, he had written in the first
edition:
‘The septum of the ventricles of the heart is very dense. It
abounds with pits on both sides. Of these pits none, so far
as the senses can perceive, penetrate from the right to the
left ventricle. We are thus forced to wonder at the art of the
Creator, by which the blood passes from right to left ventricle
through pores which elude the sight.’ (Compare Fig. 21, p. 59.)
This passage is altered to something quite different in the second
edition, where he writes:
‘Although sometimes these pits are conspicuous, yet none, so
far as the senses can perceive, passes from the right to the
left ventricle. I have not come across even the most hidden
channels by which the septum of the ventricles is pierced. Yet
such channels are described by teachers of Anatomy, who have
absolutely decided that the blood is taken from the right to
the left ventricle. I, however, am in great doubt as to the
action of the heart in this part.’
He further sets forth his whole policy with reference to Galen’s view
in the following interesting passage:
‘In considering the structure of the heart and the use of its
parts, I bring my words for the most part into agreement with
the teachings of Galen; not because I think these on every
point in harmony with the truth, but because, in referring at
times to new uses and purposes for the parts, I still distrust
myself. Not long ago I would not have dared to diverge a hair’s
breadth from Galen’s opinion. But the septum is as thick, dense
and compact as the rest of the heart. I do not, therefore, see
how even the smallest particle can be transferred from the
right to the left ventricle through it. When these and other
facts are considered, many doubtful matters arise concerning
the blood-vessels.’
The work terminates with a little chapter _On the dissection of living
animals_. We note that this, while dealing skilfully with the methods
of physiological experiment, does not exhibit any very marked advance
on the views of Galen.
Among the experiments on living animals that Vesalius enumerates are
excision of the spleen, the loss of which he showed was consistent
with life; and the cutting of the nerves that supply the organ of
voice, with resultant loss of that faculty. He demonstrated that
longitudinal section of a muscle interferes little with its function,
but cross section produces disability in proportion to the injury.
Such experiments had been performed by Galen, who had also reached the
same conclusion as Vesalius, that it is through the spinal cord that
the brain acts on the various muscles of the limbs and trunk. Vesalius
repeated Galen’s experiments on section of the spinal cord (p. 58). The
most striking of his experiments were those on respiration. Here he
showed that, even though the chest-wall be pierced, the animal may be
kept alive if the lungs are continuously aerated by means of a bellows,
and that a flagging heart may be revived by similar means.
The work of Vesalius at once placed the knowledge of the human body
in a new position. It cannot be said that he completed the task of
describing the naked-eye structure of the human body. Yet he went so
far towards this that no dramatic improvement has since been made
upon his methods. It is a fair statement that the whole of modern
Descriptive Anatomy may be treated as a comment and correction and
amplification of Vesalius. His work moreover stimulated a host of
investigators.
[Illustration: FIG. 32. SKELETON from the anatomical work of Vesalius,
1543.
It is beautifully and dramatically posed, and the drawing is remarkably
accurate. The figure leans against a tomb, contemplating a skull. In
the front left-hand corner of the top of the tomb is a part of the bony
structure which supports the organ of voice (H).
The inscription on the tomb may be translated ‘Man’s spirit lives. The
rest is Death’s portion’.
The inscription at the top may be translated: ‘A delineation from the
side of the bones of the human body, freed from the other structures
which they support and placed in their correct positions.’ ]
§ 2. _The Anatomical Reaction on Surgery._
The immediate effect of the new knowledge of Anatomy was an improvement
in Surgery. The Wars of Religion of the sixteenth and seventeenth
centuries were fierce and prolonged, and the army surgeons of the time
had much experience of the treatment of wounds. The most prominent of
the military practitioners was the Frenchman, Ambroise Paré (1517-90).
He perceived the importance of anatomical knowledge and adapted his
discoveries to the needs of Surgery. Paré did much to elevate the
surgeon’s profession from a despised handicraft to a position equal to
that of other branches of the healing art.
Apart from the introduction of anatomical discipline into Surgery,
Paré’s four contributions to the surgical art were, firstly, his
discovery that gunshot wounds are not ‘poisonous’ as had theretofore
been thought, and that therefore they do not require the application
of boiling oil, but are best healed by soothing applications;
secondly, the cognate doctrine that bleeding after amputations should
be arrested, not by the terrible method of indiscriminate use of the
red-hot cautery, but by simple ligature; thirdly, his advocacy of
the method of turning the child in its mother’s womb before delivery
in certain abnormal cases; and fourthly, his ingenious devising of
artificial limbs (Fig. 33). None of these four was without precedent.
Nevertheless, the eminence, skill, and wide experience of Paré were
the main factor in the spread of these practices. But the greatest
of all Paré’s contributions to surgery was the service of his own
personality, the example of his steadfast efforts to increase his
knowledge of human anatomy and his skill in the art, and his constant
emphasis on the surgeon’s duty to exert his utmost efforts to avoid or
relieve the patient’s suffering.
[Illustration:
FIG. 33. ARTIFICIAL ARMS AND HANDS, designed and figured by Ambroise
Paré, and used by him for wounded soldiers from about 1560 onwards.
]
In a famous passage Paré describes how he, a ‘freshwater soldier’, on
his first campaign, watched the other surgeons following the old rule
of treating all gunshot wounds with boiling oil. At first he formed
his practice on theirs. The theory was that gunshot wounds contained a
poison, which the boiling oil was believed to drive out. Paré tells of
his agitation when one evening, his supplies having run out, men had to
be treated without the boiling oil. Next morning he was astonished to
find that every man whose wounds had been treated only with a salve had
rested fairly comfortably, while all who had undergone the customary
treatment were, as we may well believe, in great pain. ‘Then I resolved
within myself never so cruelly to burn poor wounded men.’ Another
saying of the shrewd old surgeon is the famous adage ‘I dressed him and
God cured him.’
Paré’s works were frequently reprinted and translated into various
European languages, including English. They exercised the widest
influence on surgical craft in the sixteenth and seventeenth centuries.
Like Vesalius, he is an example and type of a large class. In every
country surgeons arose who made an effort to utilize the new anatomical
knowledge.
§ 3. _The Renaissance of Internal Medicine._
Internal Medicine lagged behind Surgery at this period. The anatomical
reforms of Vesalius were unaccompanied by any commensurate advance in
physiological knowledge, and without a scientific Physiology there can
be no science of Internal Medicine. The practice of the physicians thus
remained in effect that of the Middle Ages. The ruling idea was still
that of the ‘four humors’ corresponding to the four ‘temperaments’
(Fig. 13, p. 34, and compare Fig. 34, p. 97).
There are, however, three respects in which we see an improvement
of the physician’s art during the sixteenth and first half of the
seventeenth century.
Firstly, there was some improvement in the medical texts that were
habitually read. More reliable translations were now available. Notably
the great Hippocratic works became more widely disseminated. They
formed a substitute for the old texts translated or mistranslated from
the Arabic.
Secondly, the extension of geographical knowledge and the formation
of settlements and colonies brought new drugs upon the market. These
were often a mixed blessing, for some of the drugs were useless and
others dangerous. Nevertheless, to this process Medicine owes several
important contributions, among them Ipecacuanha, Cinchona (p. 326),
and, by no means least, Tobacco (Fig. 35). Apart from the amenities
introduced by Tobacco, it was for long of great value as a narcotic
drug. Moreover, there was a corresponding advance in Botany. The
movement was cursed with the ‘practical’ spirit, and only those plants
thought to have an application as drugs were exactly figured and
described. Nevertheless, the beautifully illustrated herbals of the
sixteenth and seventeenth centuries exercised, by the care and accuracy
of their execution, an exemplary influence on the development of
Biological Science in general and of Medical Science in particular.
Thirdly, there was some advance in the knowledge of the natural history
of infectious disease. A rational theory of the nature of infection was
placed before the public as early as 1546 by the Veronese physician,
Girolamo Fracastoro (1483-1553). He regarded infection as due to the
passage of minute bodies from the infector to the infected. These
hypothetical minute bodies had the power of self-multiplication. The
conception bore a superficial resemblance to the modern germ theory of
disease. An important contribution to the conception of epidemics was
also made by the French physician Guillaume de Baillou (1538-1616),
who reintroduced the old Hippocratic idea of ‘Epidemic Constitution’,
i.e. that particular seasons and particular years are of their nature
subject to particular diseases. The idea was extended and developed by
the English physician Thomas Sydenham (1624-89), and it still has its
value.
[Illustration:
FIG. 34. FIGURE ILLUSTRATING THE ‘FOUR TEMPERAMENTS’, from the Guild
Book of the Barber-Surgeons of York, now in the British Museum. The
figure was prepared about 1500. Above, to the left, is the _Melancholy_
man, and to the right the _Sanguine_. Below to the left is the
_Choleric_ man, and to the right the _Phlegmatic_. On the scroll work
is written in English ‘Ther ar the iiij umors, thath ar oderwysse calde
the iiij complecconis thath ar resceuid un to the iiij elementis,
Hafyng the kynd of humors’, which may be rendered ‘There are the 4
humors, that are otherwise called the 4 complexions, that are received
unto the 4 elements, having the nature of humors’. For the theory
compare Fig. 13, p. 34.
]
In connection with their epidemiological work these three men,
Fracastoro, de Baillou, and Sydenham, made significant additions to
the knowledge of particular infectious conditions. Thus, during the
sixteenth and seventeenth centuries there arose an exact body of
teaching concerning acute infectious diseases which was the necessary
prelude to the introduction of more effective preventive measures at
a later date. To one infectious disease we may refer more particularly.
During the Middle Ages there had smouldered in various districts an
obscure disease, sometimes more or less dimly distinguished under
various specific names, but most frequently confused with Leprosy.
Towards the end of the fifteenth century this disease, which was still
imperfectly distinguished in men’s minds from Leprosy, broke out in
epidemic and virulent form all over Europe. It caused great destruction
of life and developed everywhere as a problem of national importance.
Various titles were given it, such as ‘pox,’ ‘the French disease’, ‘the
Spanish disorder’. Only tardily was it recognized that the disease
was usually of venereal origin. Not till 1530, on the suggestion of
Fracastoro, did it receive its modern cognomen _Syphilis_. From the
time of its recognition, Syphilis has been pursued by a portentous
mass of literature, the mere sifting and verification of which is a
formidable task. Alarm, misunderstanding, religious feeling, false
modesty, wilful misrepresentation, and change in type of the disease
itself have all contributed their quota of obscurantism and fable to a
naturally difficult subject (Figs. 35 and 36). Fracastoro did something
to bring order out of the confusion. To him also we owe the first good
scientific descriptions of several other destructive diseases, among
which Typhus fever, now known to be conveyed by lice (p. 258), takes a
prominent place.
[Illustration:
FIG. 35. THE EARLIEST PICTURE showing the use of Tobacco. From a
work on Brazil, printed in Paris in 1558. In the center of a native
hut stands an Indian suffering from Syphilis. Behind him, on the
left, a man smokes a huge cigar over him as a curative measure.
Right and left his arms are held by two figures who seek to suck
the poison out of him. Another offers him a curative plant. Behind
him is a ‘hammock’--the word is of American-Indian origin and means
‘tobacco-bed’. Above his head are a monkey, a parrot, and a bale of
tobacco.
]
De Baillou (1538-1616) first described Whooping Cough, and was the
first to use the word _Rheumatism_ in the modern sense. He was moreover
the first, since Hippocrates, to distinguish between Rheumatism and
Gout. De Baillou’s works deeply influenced Sydenham, who held very
similar epidemiological views, and uses a somewhat similar vocabulary
(p. 100).
We have seen how the knowledge of Anatomy forwarded Surgery, while,
with the lag in Physiology, Internal Medicine remained in a backward
state. It is well to recall however that a knowledge of Anatomy and
Physiology will not, of themselves, make a man a scientific physician.
The object which presents itself to a physician is neither a living
anatomy nor a physiological model. It is a sick and suffering patient.
The physician’s first task is to examine exactly the phenomena of
sickness and suffering, and in doing this the first demand on his
knowledge will be the history and fate of others who have endured like
sickness and suffering. When he has ranged these instances in his mind
he may turn, for explanation and relief, to the resources suggested
by other sciences, Anatomy and Physiology among them. But all the
Anatomy and Physiology in the world will not aid the practitioner who
is unacquainted with the natural history of disease. This is the truth
that was firmly seized by Thomas Sydenham.
The Natural History of Disease was a subject which Sydenham pursued
with lifelong devotion. Before his time the phenomena of disease had
been classified, subdivided, discussed, and treated with all the
subtlety and skill of scholastic thought. Men had now and again shaken
themselves free from the shackles of the medieval system, and had
here and there corrected the views of Galen or amplified the limited
achievements of their predecessors. Yet none before Sydenham had set
himself to consider all the actual cases of disease that lay before him
as a subject of scientific description and analysis. That was the great
achievement of the ‘English Hippocrates’. We should not find it easy
to point to any important discovery to associate with his name. But he
did more than discover. He initiated a new mode of approach. He was the
founder of modern Clinical Medicine.
In 1666 Thomas Sydenham published his classic work, _The Method of
Treating Fevers_, dedicated to his friend Robert Boyle, ‘the Father
of Chemistry’ (pp. 124-6). The book opens with the almost Hippocratic
phrase ‘A disease, in my opinion, how prejudicial soever its cause may
be to the body, is no more than a vigorous effort of Nature to throw
off the morbific matter, and thus recover the patient’. We have here
the _healing power of Nature_ of Hippocrates (p. 21), which had been
obscured and overlaid in the twenty centuries which lay between the
two great physicians. The works of Sydenham may reasonably be regarded
as the first great commentary on the Hippocratic theme. Sydenham set
well on its way the conception of infectious conditions as specific
entities, a conception which has since been illuminated by the germ
theory of disease (p. 224 ff.).
[Illustration: FIG. 36. Allegorical picture illustrating the venereal
plague Syphilis.
From a work printed in Germany in 1496. The Virgin sits enthroned on
clouds, crowning a crusader, who kneels at her right hand. The Holy
Child on her knee sends forth the plague of Syphilis as a scourge on
mankind. Two women, spotted with the rash of the disease, kneel in
supplication before her on her left. In the foreground of the picture
lies a corpse dead of the disease, the speckled ravages of which may be
seen upon it.
]
§ 4. _The First Physical Synthesis._
Manifestations of the Human Spirit are not accustomed to confine
themselves exactly within the convenient limits of the centuries.
Nevertheless, it happens that in the History of Science the year 1600
does, in fact, correspond to something of the character of a real
change in the current attitude to Nature. That year really ushers in
the era of physical experiment. The last of the great transitional
thinkers who mark the waning of Renaissance philosophy was Giordano
Bruno, the martyr of science.