DISCOVERIES CONCERNING OUR BODIES
Should we know our own anatomy?—Curious ideas of the Ancients—Harvey's discovery of the
circulation of the blood—A large model of the human heart—Why the earliest anatomists
made little progress—Scene in a graveyard—Stealing a corpse from the gallows—What
led Harvey to his discovery—Mysterious spirits within the body—Discovery of "cells
"—Great impetus to medical science—The human brain—Some curious
 IT is remarkable how very little of his own body is known by the average man. There is an idea abroad
that the less a person knows of his bodily organs the more peace of mind he will have, the argument
being that the more he knows, the more will he imagine all sorts of ailments. The author's
experience has been that those who know least imagine most; they picture things that could not
possibly occur. If we understood really the functions of our various organs, and if we acted
according to such knowledge, we should doubtless suffer less. However, our present subject is not
hygiene nor yet physiology, but more properly the history of physiology; we desire to see how man
came to discover the meaning of the different parts of his own anatomy.
The Ancients had some curious ideas of the functions of their different organs. They believed the
mind to be situated in the kidneys, and did not connect the brain with the actions of thought. The
heart was the seat of the soul, and from the heart came forth good or evil. We still use
 such expressions as "a good heart" or "a hard heart" as being descriptive of a person's nature, but,
of course, we do so only in a figurative sense. In passing, it may not be out of place to remark
that in teaching the young it is a mistake to carry the symbolic idea too far. For instance, a
clergyman tells the children that their hearts are hard as stone, or black with sin. The child
pictures the actual heart, indeed there has been no attempt to cause it to think otherwise, the
symbol becomes the reality, and to some thoughtful children the idea appears absurd, and more harm
than good is done. There is no doubt that even in adults a great deal of religious doubt arises
simply from mistaking symbols for realities. Symbols are of much value so long as they are
recognised as symbols.
The ancient belief that the mind was located in the kidneys will explain to us such Old Testament
phrases as "They had the Lord in their mouths, but not in their kidneys." In similar fashion the
Ancients believed the bowels to be the seat of all tender emotions, and the spleen to be the organ
The great Aristotle, whose scientific dogmas were unquestioned for century after century, declared
that the brain was a sort of cooling chamber through which the blood was passed in order to prevent
its temperature rising too high. It is remarkable that one ancient philosopher, who lived five
hundred years before the time of Christ, did declare the brain to be the seat of the mind and the
source of feeling and movement, but no heed was paid to these "ridiculous notions." Very gradually
it became evident that this theory was correct, yet there was little actual progress made in gaining
information concerning the brain until modern times.
A MODEL OF THE HUMAN HEART
THIS MODEL IS OF INTEREST IN CONNECTION WITH HARVEY'S GREAT DISCOVERY OF THE CIRCULATION OF THE BLOOD.
THE INSET IN THE LEFT-HAND CORNER SHOWS THE MODEL WHEN CLOSED, AND INDICATES WHERE THE BLOOD ENTERS
AND LEAVES THE HEART.
 Perhaps the one discovery which stands out most prominently in the mind of the average man is
Harvey's discovery of the circulation of the blood. We shall see presently that there is another
discovery of even wider influence, but Harvey's discovery has been of immense importance.
Before considering what led up to this great discovery made by Dr. William Harvey, who acted as
physician to King Charles I, nearly three hundred years ago, it will be well to keep in mind a
simple picture of the circulatory system.
In the illustration facing this page we see a large model of the human heart. The inset photograph
shows the outward appearance, while the larger picture, with the interior displayed, will help to
make matters quite plain to anyone who has not considered the subject. It will be observed that
there are four distinct chambers in this hollow muscle which we call the heart. The lower left-hand
chamber drives the blood out into those tubes or blood-vessels which we call the arteries. These
arteries carry the blood to every part of the body; they branch off as they go, dividing and
subdividing again and again till they terminate in thread-like tubes so very small that they cannot
be seen without the aid of a microscope. From these extremely fine endings of the arteries the blood
escapes and is transferred to similar thread-like tubes which are attached to the small veins, and
these act as tributaries to larger veins, and so on, leading back to the top chamber on the opposite
side of the heart. During this circular course the blood has carried nourishment to all parts of the
body, and has also conveyed waste matter to the various organs capable of dealing with it. Therefore
the bright arterial blood which set out from the left-hand side of the heart has been returned to
the right-hand side as blood with
 less nutriment and more waste matter, and has a purple colour. This venous blood passes down into
the lower chamber of the right-hand side, and from there it is forced, by the contraction of the
heart, into blood-vessels leading to the lungs. These blood-vessels end in similar thread-like tubes
like those in the main system. The air-tubes of the lungs also end in similar fine tubes, through
the thin walls of which the oxygen of the breathed air passes into chemical combination with the
blood, while the waste carbonic acid passes out.
When the blood is oxygenated by the lungs it returns by blood-vessels as before, and this time to
the upper chamber on the left-hand side. Thence it passes to the lower chamber on the same side,
which brings our consideration back to the point from which we set out originally. It will be
observed that there are two distinct systems, one from the left-hand side of the heart throughout
the entire body and back to the right-hand side of the heart; the other system is from the
right-hand side of the heart to the lungs and back to the left-hand side, the latter being a very
much simpler system.
Long before the days of William Harvey it was known that blood flowed from the heart to the lungs
and back to the heart, and it was even observed that the blood was "made thin "by the air. The
discoverer of this fact writes rather sarcastically thus: "Anatomists, not very wise, begging their
pardon, think that the lungs receive the I know not what smoky fumes discharged from the heart.
About this, all one can say is that it pleases them, for they certainly seem to think that the same
state of things exists in the heart as in the chimney, as if there were green logs in the heart
which gave out smoke when burnt," Then he
 proceeds to expound his own discovery that the blood merely returns, as he describes it, "mixed with
air," and he lays emphasis upon the fact that he is not merely expounding a theory but an actual
discovery which he has made by examining both dead bodies and living animals.
There was no thought of a circulatory system throughout the body; it being believed that the heart
sent blood to all parts of the body where it was used up, fresh blood being continually
We cannot blame the early anatomists for having made so little progress in their knowledge of the
human body; indeed, we can blame only the Church as the cause of this ignorance. The human corpse
was considered so sacred that doctors were not allowed to examine it, punishment being attached to
any disobedience. It was not long before Harvey's time that the Church began to lose its power in
The early anatomists were free to examine any bones of skeletons which might be found in old and
superficial burying-grounds, so that the anatomy of the skeleton was known before the physiology of
the body. Two enthusiasts of those days relate how they were searching an old burial-place in Paris
when they were attacked by a band of wild, hungry dogs, who had come also in search of bones, but
for a different purpose. These same two anatomists found it so difficult to procure a corpse for
examination that they tried to steal the body of a man who had been hanged and left on the public
gallows as a warning to others. The enthusiasts made this attempt in broad daylight, but were caught
when climbing the gallows, and were shut out of the city. However, they returned when night came on,
and succeeded in securing their object. One of these daring
 enthusiasts was Andreas Vesalius, who wrote a pioneer work which laid the foundations of modern
anatomy and modern physiology. This book was written thirty years before William Harvey was born,
and it was the work of Vesalius that formed the basis of Harvey's great discovery.
This great discovery associated with the name of Harvey was that the heart did not keep sending out
newly made blood, but that the blood after passing throughout the body actually returned to the
heart, from which again it went to the lungs to be revitalised, returning once more to the heart,
and again throughout the body, keeping up a regular circulation.
All this seems very simple to us, but when Harvey first sought after the truth by means of
vivisections he found it so difficult to trace the action that he began to think "that the motion of
the heart was only to be comprehended by God." It was only with very patient study and the
examination of many animals that he hit upon the truth. Anatomists knew of the presence of veins
carrying dark-coloured blood, but they believed that this blood was flowing from the heart just as
the bright arterial blood was, and that the body required these two different bloods to nourish it.
It is said sometimes that it was the presence of the little pocket-like valves in the veins which
led Harvey to his discovery (these little valves prevent the blood passing backwards through the
veins), but it seems quite clear from Harvey's own writings that it was not this which gave him the
clue. He tells us that it was the great quantity of blood passing from the heart which led him to
the truth. He could not account for the production of so much blood,
 and he says: "I began to think whether there might not be a motion, as it were in a circle." When he
had grasped this idea, he found that it would explain many difficulties, and he was able to prove
that there was a real circulatory system, not only from the heart to the lungs and back, but also,
what was much more difficult to imagine, a complete circulation throughout every part of the body.
We might say also that Harvey discovered there were no such things as mysterious spirits at work
within the body. Formerly it was supposed that there were natural, vital, and animal spirits which
took an active part in the work of the blood-vessels, but now this simple mechanical circulatory
system cleared away the necessity for these, and gave a reasonable explanation of the blood passing
through other organs such as the liver and kidneys. It was soon recognised that the blood not only
carried nourishment to all parts of the body, but that it also carried the waste matter, due to the
wear and tear of the tissue, to be disposed of by the lungs, the skin, the kidneys, and the liver.
But for our present purpose we do not require to know any more physiology than will enable us to
appreciate one or two of the most outstanding discoveries concerning our own bodies.
There is no doubt that the most far-reaching discovery was made in the nineteenth century, and this
was when it was discovered that all living matter, whether vegetable or animal, is built up of
microscopic particles which we call "cells." The very simplest form of living creature, such as the
Foraminifera mentioned in an earlier chapter, is composed of one or more of these unit cells; minute
specks of protoplasm or jelly-like substance. The human body is composed of many millions of such
cells; not only
 the soft tissue but the fibres, the nerves, and the bones. One of the greatest of anatomists has
said that this discovery of the cells is "the greatest discovery in the natural sciences in modern
The names most prominently associated with this discovery are those of the two German physiologists
Schwann and Schleiden. This great discovery is one of the triumphs of the microscope. Professor
Schafer has said, in his famous address to the British Association when dealing with the origin of
life, that we could never have guessed that we were formed of aggregates of cells, each possessing
its own life, each cell being the direct descendant of another. "Nor could we suspect by intuition
that what we term our life is not a single indivisible property, capable of being blown out with a
puff like the flame of a candle; but is the aggregate of the lives of many millions of living cells
of which the body is composed."
The great advance in medical science made during the nineteenth century is due to this discovery
that our bodies are great colonies of living cells. One particularly interesting extension of this
discovery was made in connection with our blood. We know that blood is a chemical solution
containing a great deal of water with nutritious substances which have been extracted from our food,
and that the solid matter in the blood is composed of red corpuscles and white corpuscles, which
are, of course, only seen with the aid of the microscope. As is pretty generally known, it is the
multitude of red corpuscles which gives the blood its characteristic colour, there being hundreds of
red corpuscles to every white one.
It has been discovered that the chief duty of the red corpuscles is to carry oxygen to every part of
the body, while
 the blood fluid removes the waste matter (wear and tear) to the different organs which dispose of
Our present interest lies in the white corpuscles, for it has been discovered that these are
independent living organisms. These little living cells act as scavengers within us, for on meeting
any particle of solid matter in the blood they surround it and by chemical means cause it to
disappear. A very interesting exhibition of these white corpuscles at work has been given by means
of the cinematograph. Actual moving pictures were taken through the microscope, and when reproduced
they showed these white corpuscles attacking some disease germs (microbes) which had gained access
to the blood. We may regard disease as a battle between these white corpuscles and the invading
germs, the final victory deciding whether the patient recovers or not, but the subject of microbes
will be dealt with in the succeeding chapter.
We know that when a person has been partially paralysed through an effusion of blood into some
portion of the brain the patient sometimes recovers the use of the affected parts. The thanks of
such patients is due to these little white corpuscles in the blood, for they have clustered round
the blood-clot which causes the trouble, and they have devoured the red corpuscles which have become
encased in a clot.
When we think of the actions of such cells we must marvel at the great Mind which created these.
Some German scientists have sought to minimise the marvellous powers of the cell as being due to
mere complex chemical actions. In opposition to this we have the declaration of the great
evolutionist, Alfred Russel Wallace, which he has made when speaking of the formation of the simple
 cell, and how it contains all the forces which lead on to the evolution. This great thinker says:
"What we must assume in this case is not merely a force. What we absolutely require is a mind far
higher, greater, more powerful than any of the fragmentary minds we see around us; a mind not only
adequate to direct and regulate all the forces at work in living organisms, but which is itself the
source of all those other forces and energies, as well as of the more fundamental forces of the
Before passing on to the epoch-making discovery of that invisible world of microbes, detected only
with high-power microscopes, it will be of interest to consider a few things which have been
discovered concerning that most interesting organ the human brain.
A very brief description of the brain may be of service in considering the discoveries concerning
its operations. It is common practice to speak of a person's brains, and one is quite entitled to do
so, as the main part of the brain is divided into two parts, forming a left-hand and a right-hand
hemisphere. Then in addition to the main part of the brain there is a small or lesser brain situated
at the back of the head and below the main hemispheres. The general appearance of the brain is that
of a soft gray material, everywhere folded upon itself. One might describe it as being crumpled or
creased together, producing the appearance of furrows. Beneath the gray matter there lies a great
white mass of nerve 'fibres connected to the gray matter like a great array of telephone wires
leading into an exchange. The gray matter is the seat of the conscious mind, and as this lies
directly beneath the skull, we see how any injury to the
 head is a serious matter. We all know that great bundles of nerves leave the brain by the spinal
cord, and are distributed to all parts of the body. It may be remarked that although the early
physiologists recognised that there existed nerves conveying impulses that give rise to sensations
and nerves controlling motions, yet the exact differentiation of these was not discovered until the
There still exists considerable mystery concerning most of the operations of the brain, but many
important discoveries have been made, and the most important of these all lie within the last fifty
We have seen already that the Ancients did not discover that the brain was the organ of thought;
probably they believed it to be too passive an organ to serve such a purpose. They were led to think
of the conscious mind as existing in the blood, for when there was any great loss of blood there was
also a loss of consciousness, and if the blood became poisoned the consciousness often became
deranged also. As they believed the heart to be the seat of the soul, it seemed reasonable to
suppose that the blood issuing from the heart should contain conscious thought. The one early
anatomist already mentioned who declared the brain to be the seat of the conscious mind was ruled
out of court by the other great thinkers of his day. And yet this pioneer was not merely guessing,
for his conclusion was based upon his discovery that when the optic nerve leading to the brain was
severed there could be no sight.
Some two hundred years later, which leaves us still about three hundred years B.C., the learned men
of Alexandria carried out careful dissections of the brain, and they were able to trace the nerves
of the special senses. Little progress was made for several centuries, till in A.D. 170 an
 important discovery was made. This was that the nerves from the brain to the body were crossed;
nerves leaving the right-hand side of the brain going to the left-hand side of the body, while those
from the left-hand side of the brain go to the right-hand side of the body. This discovery has
proved of much value, but progress at that time and right through the Middle Ages was imperceptible.
We know that the practical death of Science during the Middle Ages in Europe was due to men trying
to work out the meaning of things by studying only the causes instead of the phenomena and trying to
trace the causes from these.
For a long time the early physiologists could not get away from the idea that the brain was a great
gland, and that it secreted a subtle substance called thought, which they spoke of as "animal
spirits," a sort of living flame. Not till the advent of the microscope did they abandon these
ideas. It was the microscope which showed that the brain was not a gland, and did not secrete
anything. Indeed, it was shown that the brain was an independent organ, having its different parts
linked up to the body by nerves.
By examining the brain in this new light it was discovered that separate portions or localities were
connected to definite parts of the body. No less than twenty-four distinct parts of the brain were
suggested to represent as many different qualities of mind, then this was increased to thirty-eight,
and later to sixty. Every individual peculiarity in a person was suggested to be due to the
development of one or other of these different parts of the brain. Then arose the art of reading the
natural "bumps" of the head by the phrenologist. Phrenology was firmly believed in by our fathers
forty years ago. The encyclopaedias of that date devote many pages to the subject and declare it
 to be a discovery of great importance even from a practical point of view. The attempts to read the
capabilities and character from the bumps of the skull was not a charlatan profession; the
originators had made a careful comparative study of skulls, but it became evident that they had not
studied a sufficient number from which to draw general conclusions. The so-called mathematical bumps
were found to be developed greatly in men who had no knowledge whatever of mathematics, while men
who were very learned in one particular subject showed no special development of the corresponding
bump. Nowadays the subject of phrenology is confined chiefly to the realms of boys' comic papers.
When the supposed discovery of phrenology was believed to be a mistaken idea, men went to the other
extreme and said that the brain had no special sections, but acted as a whole, and although it was
known that the brain was a double organ, it was considered that the two parts acted just as the two
separate lungs act.
Then came a really great discovery. An eminent physician in France found on making a number of
post-mortem examinations on the brains of persons who had died with paralysis of the right side of
the body that in every case not only was the injury to the brain on the left side, but when the
person had lost the power of speech there was in each case an injury to one particular area of the
brain. It was clear that speech was controlled by one specific part of
 the brain, and yet the anatomists would not accept the truth of this discovery for several years.
This attitude was probably due to the fact that the new discovery seemed to corroborate the idea of
phrenology, for by this time the physicians had rejected phrenology, although the general public
continued to believe in the art for many years.
Other important discoveries followed and confirmed this fact concerning the special functions of
different parts of the brain. One of the most interesting steps was the discovery of the cause of a
very strange symptom in brain diseases known as "aphasia." One or two well-known cases will
illustrate this phenomenon.
Professor W. A. Thomson, of New York, relates how he was hurriedly sent for on one occasion by an
old patient whom he found to be much disturbed by a strange experience which had befallen her. The
previous day she had put an advertisement in the newspapers for a waitress, and when the girls
applied the next morning the lady found that she could not read their references. She then took up
the printed newspaper and found that she could not read a word of it either. At first she thought
that something had gone wrong with her eyesight, but she could see all around her distinctly, and
she could even see to do her crochet work. As a last test she opened her Bible, thinking to turn to
some part that she knew well, but she could recognise nothing in, it. She saw the pages and the
printing, but the words had no meaning to her. Then she sent off post-haste for the doctor. He tried
to calm her excitement as best he could, and explained to her that a small blood-vessel supplying a
very small area in the brain had failed to do its duty by becoming clogged. In this particular area
she had built up her knowledge of written words; all the
 experience of words which she had acquired by means of her eyes was cut off from access for the time
being. It was some consolation to her that she could still recognise spoken words; her knowledge of
these had been gained by her ears, and the record of these was in a different small area of the
brain. She could express herself perfectly in speech, but she could not write a single word.
Unfortunately, she did not recover her power of reading; the white corpuscles of the blood failed to
remove the obstacle.
The case of a young man of thirty was different, and was much more alarming. He was a clerk in a
mercantile warehouse, and his people thought he had suddenly become insane, for he commenced to talk
a complete gibberish, and could not understand what his friends said to him. Fortunately, it was
found that he could still read and write, and to every written question he could give a perfectly
intelligent answer. The poor fellow had become word-deaf through a cause similar to that in the case
of word-blindness, just referred to, but in his case it was a different part of the brain which had
been cut off from its blood supply. His hearing was not affected in any way; he could recognise and
appreciate all sounds, but words had no meaning to him.
Such cases are fortunately rare, but there is a considerable variety of experience. One learned man,
who was master of several foreign languages, suddenly found that he could not read any letter
written in English, although he could read, very hesitatingly, words printed in English; English was
his mother tongue. He was a most proficient French scholar, but now he could not read a word of
French, although he could still speak that language. He could only make a little sense of Latin
books with which he had been perfectly familiar. His Greek remained as it was, but as
 this was the only language he could write now, he was greatly handicapped in correspondence.
From such phenomena as those just described it was discovered that in a particular part of the
brain, a little mass of gray matter no larger than a hazel nut, there are registered all the
multitudes of words which we know.
Another interesting discovery has been made, it being found that the word and speech centres of the
majority of people are in the left hemisphere of the brain; but that in the case of left-handed
people their speech centres are in the right hemisphere. What led to this discovery was the fact
that in cases of paralysis, when there had been loss of speech, it had been generally the right side
of the body which had been paralysed. And further, that when loss of speech accompanied paralysis of
the left side of the body, in such cases it was found that the patient had been left-handed. A
further study by means of post-mortem examinations showed that the speech area was in the left
hemisphere of the brain of all right-handed patients, and in the right hemisphere of the brain in
cases of left-handedness.
It goes without saying that we are born without the register of a single word in the brain, and that
the building up of the records is a very gradual process. It is apparent that these registers are
made in the particular hemisphere which controls the hand with which the child seeks to do things,
and upon which it concentrates attention. It is apparent that there is a direct connection between
speech and the gesture of the arms.
The large majority of us are either right-handed or left-handed, there being very few people really
"ambidexterous," or able to use both hands equally well. The Japanese made an experiment of training
a number of
 children to use both hands equally, but the result was not satisfactory. It was found that no child
trained in this fashion was ever so expert with either hand as a right-handed or left-handed child.
No information is available as to whether there were two speech areas brought into use, indeed, so
far as the author knows, this question has never been discussed.
It is patent that everything which is stored in the brain has been derived from without by way of
the sensations, and it is evident that the chief gateways are the eye and the ear. Hence our
difficulty in teaching the blind and the deaf. The most remarkable illustration of these facts is to
be seen in the life story of Helen Keller, who, when she was still an infant of nineteen months,
became blind, and deaf, and consequently dumb. The only gateways she had left were the senses of
smell, taste, and touch. It would seem absolutely hopeless to get such a child to learn anything:
but at the age of seven years she was taught to trace upon her hand such words as "doll" and
"water." In less than a month the child could trace eighteen nouns and a few verbs, but she could
only repeat the tracings made by her teacher; the child had no idea what the tracings meant. How
could this meaning be shown to her? Her teacher took her to a water-pump and let her hold a mug to
receive the water, and when the water flowed over on to the girl's hand she (the teacher) traced
anew the word water on the palm of the child's hand. All at once the girl dropped the mug, and a
bright look came into her face. She traced the word water several times on the palm of her hand, and
indicated that she understood. She was so delighted with her new knowledge that she even tried to
teach her pet dog the meaning of the word water by tracing the letters on its paw.
 Those who have not read the life-story of Hellen Keller have missed much. In the fourth year of her
education we find her becoming a true scientist, writing down such questions as: "Who made the Earth
and the seas and everything? What makes the Sun hot? Why does not the Earth fall; it is so large and
heavy?" And so on. She not only took a most intelligent interest in things, but she succeeded in
taking a University degree. Her subjects included Advanced Greek, Advanced Latin, Algebra, and
Geometry, in some of which she passed with honours. However, our present interest lies in the fact
that a brain may be so stored with knowledge, although the usual gateways are permanently closed.
Surely this remarkable case ought to act as a stimulus to those of us who have all our gateways
Some of us have been trusted with fewer talents than others, but from what has been discovered
concerning the brain it must be clear that we ourselves are responsible for the making of our
"brains." No matter how fortunate an individual may have been in receiving a very plastic brain, we
are all born with brains which contain no knowledge whatever. We are left to acquire this. It has
been said—"a great personality may make a brain, but no brain can make a great personality."
The discoveries concerning the brain have enabled surgeons to make many wonderful operations. In
cases of paralysis of some particular parts of the body the surgeon has been able to know exactly
the area of the brain in which the disorganisation has taken place. In many such cases he has been
able to diagnose that the trouble is caused by a tumour, and he has been able to open the skull at
the exact spot and to remove the source of the trouble.