D. S. (David Samuel) Margoliouth.

The Popular science monthly (Volume 19) online

. (page 100 of 110)
Online LibraryD. S. (David Samuel) MargoliouthThe Popular science monthly (Volume 19) → online text (page 100 of 110)
Font size
QR-code for this ebook

beyond the orbit of the planet Jupiter.

About the 22d of June last, a comet flashed into view which was un-
expected as it was brilliant. It was seen with the unassisted eye by a
multitude of persons in widely separated localities. Among the ear-

June ^8.

liest of those who discovered its presence in the northern sky was Mr.
G. W. Simmons, of Boston, Massachusetts, who chanced to be in camp
at Morales, Mexico. This gentleman first saw it on the morning of
June 20th. It had, however, been discovered nearly one month earlier


by Mr. Tebbutt, of New South Wales, Australia, on IVIay 22d. During
the interval between these two dates it had moved noi-thward througli
an arc of more than 60°, which rapid motion accounts for its sudden
apparition in our northern sky.

The relative situation of the orbits of the comet and the earth will
])e best understood by the perspective view of a model of the two
orbits constructed to scale (Fig, 2). This model was executed, from
elements computed by Messrs. Chandler and Wendell, of Harvard
College Observatory, by Ensign S. J. Brown, U. S. N., who kindly
placed it at the service of the writer.

In this cut, the horizontal plane represents the position of the
earth's orbit, and the plane cutting this at a lai'ge angle represents the
plane of the comet's orbit. The comet moved from below, which is
the southern side, up through the plane of the earth's orbit to the
northern side. The dates indicate the positions of the earth and
comet at different times in their respective orbits. It passed its peri-
helion point just before passing through the plane of the earth's orbit.

The orbit of the comet is inclined to the plane of the earth's orbit
at an angle of 63°. Its perihelion distance is 0*T7 of the earth's dis-
tance from the sun. It arrived at its perihelion June 16th, and was
nearest the earth June 19th, when its distance from the earth was 0-28
of the earth's distance from the sun.

The nucleus attained fully the brightness of a first-magnitude star,
and the length of the tail was variously estimated at fi*om 20° to 30°.
This comet is still faintly visible to the naked eye (August 22d).

At first it was suspected that this comet was identical with that of
1807, but later investigation disproved this supposition.


Bt Pbofessob T. H. HUXLEY.

THE great body of the theoretical and practical knowledge which
has been accumulated by the labors of some eighty generations,
since the dawn of scientific thought in Europe, has no collective Eng-
lish name to which an objection may not be raised ; and I use the
term "medicine" as that which is least likely to be misunderstood;
tliough, as every one knows, the name is commonly applied, in a nar-
rower sense, to one of the chief divisions of the totality of medical

* Address at the Iiitcniatiouul Medical Congress, by Professor T. 11. Huxlev, LL, D.,
Secretary to the Royal Society.


Taken in this broad sense, " medicine " not merely denotes a kind
of knowledge, but it comprehends the various applications of that
knowledge to the alleviation of the sufferings, the repair of the in-
juries, and the conservation of the health, of living beings. In fact,
the practical aspect of medicine so far dominates over every other,
that the " healing art " is one of its most widely received synonyms.
It is so difficult to think of medicine otherwise than as something
which is necessarily connected with curative treatment, that we are
apt to forget that there must be, and is, such a thing as a pure
science of medicine — a " pathology " which has no more necessary
subservience to practical ends than has zoology or botany.

The logical connection between this purely scientific doctrine of
disease, or pathology, and ordinary biology, is easily traced. Living
matter is characterized by its innate tendency to exhibit a definite
series of the morphological and physiological phenomena which con-
stitute organization and life. Given a certain range of conditions, and
these phenomena remain the same, w^ithin narrow limits, for each kind
of living thing. They furnish the normal and typical characters of
the species ; and, as such, they are the subject-matter of ordinary

Outside the range of these conditions, the normal course of the
cycle of vital phenomena is disturbed ; abnormal structure makes its
appearance, or the proper character and mutual adjustment of the
functions cease to be preserved. The extent and the importance of
these deviations from the typical life may vary indefinitely. They
may have no noticeable influence on the general well-being of the
economy, or they may favor it. On the other hand, they may be of
such a nature as to impede the activities of the organism, or even to
involve its destruction.

In the first case, these perturbations are ranged under the wide and
somewhat vague category of " variations " ; in the second, they are
called lesions, states of poisoning, or diseases ; and, as morbid states,
they lie within the province of pathology. Ko sharp line of demar-
kation can be drawn between the two classes of phenomena. No one
can say where anatomical variations end and tumors begin, nor where
modification of function, which may at fii'st promote health, passes into
disease. All that can be said is, that whatever change of structure or
function is hurtful belongs to pathology. Hence it is obvious that
pathology is a branch of biology ; it is the morphology, the physiol-
ogy, the distribution, the etiology of abnormal life.

However obvious this conclusion may be now, it was nowise ap-
parent in the infancy of medicine. For it is a peculiarity of the physi-
cal sciences, that they are independent in proportion as they are im-
perfect ; and it is only as they advance that the bonds which really
unite them all become apparent. Astronomy had no manifest connec-
tion with terrestrial physics before the publication of the " Principia" ;


that of chemistry with physics is of still more modern revelation ;
that of physics and chemistry with physiology has been stoutly denied
within the recollection of most of us, and perhaps still may be.

Or, to take a case which affords a closer parallel with that of medi-
cine. Agriculture has been cultivated from the earliest times, and
from a remote antiquity men have attained considerable jiractical skill
in the cultivation of the useful plants, and have empirically established
many scientific truths concerning the conditions under which they
flourish. But it is within the memory of many of us that chemistiy
on the one hand and vegetable physiology on the other attained such
a stage of development that they were able to furnish a sound basis
for scientific agriculture. Similarly, medicine took its rise in the prac-
tical needs of mankind. At first, studied without reference to any
other branch of knowledge, it long maintained, indeed still to some
extent maintains, that independence. Historically, its connection with
the biological sciences has been slowly established, and the full extent
and intimacy of that connection are only now beginning to be appar-
ent. I trust I have not been mistaken in supposing that an attempt to
give a brief sketch of the steps by which a philosophical necessity has
become an historical reality, may not be devoid of interest, possibly of
instruction, to the members of this great Congress, profoundly inter-
ested as all are in the scientific development of medicine.

The history of medicine is more complete and fuller than that of
any other science, except, perhaps, astronomy ; and, if we follow back
the long record as far as clear evidence lights us, we find ourselves
taken to the early stages of the civilization of Greece. The oldest hos-
pitals were the temples of ^sculapius ; to these Asclepeia, always
erected on healthy sites, hard by fresh springs and surrounded by
shady groves, the sick and the maimed resorted to seek the aid of the
god of health. Votive tablets or inscriptions recorded the symptoms,
no less than the gratitude, of those who were healed ; and, from these
primitive clinical records, the half-priestly, half-philosophic caste of
the Asclepiads compiled the data upon which the earliest generaliza-
tions of medicine, as an inductive science, were based.

In this state, pathology, like all the inductive sciences at their
origin, was merely natural history ; it registered the phenomena of
diseases, classified them, and ventured upon a prognosis, wherever
the observation of constant coexistences and sequences suggested
a rational expectation of the like recurrence under similar circum-

Further than this it hardly went. In fact, in the then state of
knowledge, and in the condition of philosophical speculation at that
time, neither the causes of the morbid state nor the rationale of treat-
ment were likely to be sought for as we seek for them now. The an-
ger of a god was a sufficient reason for the existence of a malady, and
a dream ample warrantee for therapeutic measures ; that a physical


phenomenon must needs have a physical cause was not tlie implied or
expressed axiom that it is to us moderns.

The great man whose name is inseparably connected with the foun-
dation of medicine, Hippocrates, certainly knew very little, indeed
practically nothing, of anatomy or physiology ; and he would proba-
bly have been perplexed even to imagine the possibility of a connec-
tion between the zoological studies of his contemporary, Democritus,
and medicine. Nevertheless, in so far as he, and those who worked
before and after him in the same spirit, ascertained, as matters of ex-
perience, that a wound, or a luxation, or a fever, presented such and
such symptoms, and that the return of the patient to health was facili-
tated by such and such measures, they established laws of nature, and
began the construction of the science of pathology. All true science
begins with empiricism — though all true science is such exactly, in so
far as it strives to pass out of the empirical stage into that of the de-
duction of empirical from more general truths. Thus, it is not won-
derful that the early physicians had little or nothing to do with the
development of biological science ; and, on the other hand, that the
early biologists did not much concern themselves with medicine. There
is nothing to show that the Asclepiads took any prominent share in
the work of founding anatomy, physiology, zoology, and botany.
Rather do these seem to have sprung from the early philosophers, who
were essentially natural philosophers, animated by the characteristi-
cally Greek thirst for knowledge as such. Pythagoras, Alemeon, De-
mocritus, Diogenes of ApoUonia, are all credited with anatomical and
physiological investigation ; and though Aristotle is said to have be-
longed to an Asclepiad family, and not improbably owed his taste for
anatomical and zoological inquiries to the teachings of his father, the
physician Nicomachus, the " Historia Animalium," and the treatise
" De Partibus Animalium," are as free from any allusion to medicine
as if they had issued from a modern biological laboratory.

It may be added that it is not easy to see in what way it could
have benefited a physician of Alexander's time to know all that Aris-
totle knew on these subjects. His human anatomy was too rough to
avail much in diagnosis, his physiology was too erroneous to supply
data for pathological reasoning. But when the Alexandrian schools,
with Erasistratus and Herophilus at their head, tui'ned to account the
opportunities for studying human structure, aiforded to them by the
Ptolemies, the value of the large amount of accurate knowledge thus
obtained to the surgeon for his operations, and to the physician for his
diagnosis of internal disorders, became obvious, and a connection was
established between anatomy and medicine, which has ever become
closer and closer. Since the revival of learning, surgery, medical di-
agnosis, and anatomy have gone hand in hand. Morgagni called his
great work, " De sedibus et causis morborum per anatomen indagatis,"
and not only showed the way to search out the localities and the



causes of disease by anatomy, l)ut himself traveled wonderfully far
upon the road. Bichat, discriminating the grosser constituents of the
organs and parts of the body one from another, pointed out the direc-
tion which modern research must take ; until, at length, histology, a
science of yesterday, as it seems to many of us, has carried the work
of Morgagni as far as the microscope can take us, and has extended
the realm of pathological anatomy to the limits of the invisible

Thanks to the intimate alliance of morphology with medicine, the
natural history of disease has, at the present day, attained a high de-
gree of perfection. Accurate regional anatomy has rendered prac-
ticable the exploration of the most hidden parts of the organism, and
the determination during life of morbid changes in them ; anatomical
and histological j^ost-mortem investigations have supplied physicians
with a clear basis upon which to rest the classification of diseases, and
with unerring tests of the accuracy or inaccui-acy of their diagnoses.

If men could be satisfied with pure knowledge, the extreme preci-
sion with which in these days a sufferer may be told what is happen-
ing, and what is likely to happen, even in the most recondite parts of
his bodily frame, should be as satisfactory to the patient as it is to the
scientific pathologist who gives him the information. But I am afraid
it is not ; and even the practicing physician, while nowise underesti-
mating the regulative value of accurate diagnosis, must often lament
that so much of his knowledge rather prevents him from doing wrong,
than helps him to do right.

A scorner of physic once said that nature and disease may be com-
pared to two men fighting, the doctor to a blind man with a club, who
strikes into the melee, sometimes hitting the disease, and sometimes
hitting nature. The matter is not mended if you suppose the blind
man's hearing to be so acute that he can register every stage of the
struggle and pretty clearly predict how it will end. lie had better not
meddle at all, until his eyes are opened — until he can see the exact
position of the antagonists, and make sure of the effect of his blows.
But that which it behooves the physician to see, not indeed with his
bodily eye, but with clear intellectual vision, is a process, and the chain
of causation involved in that process. Disease, as we have seen, is a
perturbation of the normal activities of a living body ; and it is, and
must remain, unintelligible, so long as we are ignorant of the nature
of these normal activities. In other words, there could be no real sci-
ence of pathology until the science of physiology had reached a degree
of perfection unattained, and indeed unattainable, until quite recent

So far as medicine is concerned, I am not sure that physiology, such
as it was down to the time of Harvey, might as well not have existed.
Nay, it is perhaps no exaggeration to say that, within the memory of
living men, justly renowned practitioners of medicine and surgery


knew less physiology than is now to be learned from the most element-
ary text-book ; and, beyond a few broad facts, regarded what they
did know as of extremely little practical importance. Nor am I dis-
posed to blame them for this conclusion ; physiology must be useless,
or worse than useless, to pathology, so long as its fundamental concep-
tions are erroneous.

Harvey is often said to be the founder of modern physiology ; and
there can be no question that the elucidations of the function of the
heart, of the nature of the pulse, and of the course of the blood, put
forth in the ever-memorable little essay " De motu cordis," directly
worked a revolution in men's views of the nature and of the concate-
nation of some of the most important physiological processes among
the higher animals ; while, indirectly, their influence was perhaps even
more remarkable.

But, though Harvey made tliis signal and perennially important
contribution to the physiology of the moderns, his general conception
of vital processes was essentially identical with that of the ancients ;
and, in the " Exercitationes de generatione," and notably in the singu-
lar chapter " De calido innato," he shows himself a true son of Galen
and of Aristotle.

For Harvey, the blood possesses powers superior to those of the
elements ; it is the seat of a soul which is not only vegetative but also
sensitive and motor. The blood maintains and fashions all parts of
the body, '■Hdque summa cum promdentia et intellectu injincm certum
acjens, quasi ratiocinio quodam utereturP

Here is the doctrine of the " pneuma," the product of the philo-
sophical mold into which the animism of primitive men ran in Greece,
in full force. Nor did its strength abate for long after Harvey's time.
The same ingrained tendency of the human mind to suppose that a
process is explained when it is ascribed to a power of which nothing is
known except that it is the hypothetical agent of the process, gave rise
in the next century to the animism of Stahl ; and, later, to the doctrine
of a vital principle, that " asylum ignorantia) " of physiologists, which
has so easily accounted for everything and explained nothing, down to
our own times.

Now the essence of modem as contrasted with ancient physiologi-
cal science, appears to me to lie in its antagonism to animistic hypoth-
eses and animistic phraseology. It oilers physical explanations of vital
phenomena, or frankly confesses that it has none to oif er. And, so far
as I know, the first person who gave expression to this modern view
of physiology, who was bold enough to enunciate the proposition that
vital phenomena, like all the other phenomena of the physical world,
are, in ultimate analysis, resolvable into matter and motion, was Rene

The fifty-four years of life of this most original and powerful think-
er are widely overlapped, on both sides, by the eighty of Harvey, who


survived bis younger contemporary by seven years, and takes pleasure
in acknowledging tbe Frencb pbilosopber's appreciation of bis great

In fact, Descartes accepted tbe doctrine of tbe circulation as pro-
pounded by " Hervaius, medecin d'Angleterre," and gave a full account
of it in bis first work, tbe famous " Discours de la Metbode," wbich
was publisbed in 1637, only nine years after tbe exercitation "De
motu cordis " ; and, tbougb differing from Harvey in some important
points (in wbicb, it may be noted, in passing, Descartes was wrong and
Harvey rigbt), be always speaks of bim witb great respect. And so
important does tbe subject seem to Descartes, tbat be returns to it in
tbe " Traite des Passions " and in tbe " Traite de I'Homme."

It is easy to see tbat Harvey's work must bave bad a peculiar sig-
nificance for tbe subtile tbinker, to wbom we owe botb tbe spiritualistic
and tbe materialistic pbilosopbies of modern times. It was in tbe very
year of its publication, 1G28, tbat Descartes witbdrew into tbat life of
solitary investigation and meditation of wbicb bis pbilosopby was tbe
fruit. . And, as tbe course of bis speculations led bim to establisb an
absolute distinction of nature between tbe material and tbe mental
worlds, be was logically compelled to seek for tbe explanation of tbe
pbenomena of tbe material world witbin itself ; and, baving allotted
tbe realm of tbougbt to tbe soul, to see notbing but extension and mo-
tion in tbe rest of nature. Descartes uses " tbougbt " as tbe equivalent
of our modern term " consciousness." Tbougbt is tbe function of tbe
soul, and its only function. Our natural beat and all tbe movements
of tbe body, says be, do not depend on tbe soul. Deatb does not take
place from any fault of tbe soul, but only because some of tbe princi-
pal parts of tbe body become corrupted. Tbe body of a living man
differs from tbat of a dead man in tbe same way as a watcb or other
automaton (tbat is to say, a macbine wbicb moves of itself), wben it is
wound up and bas in itself tbe physical principle of tbe movements
wbicb tbe mechanism is adajited to perform, differs from tbe same
watcb or other macbine wben it is broken, and the physical principle
of its movement no longer exists. All the actions which are common
to us and the lower animals depend only on the conformation of our
organs and tbe course which the animal spirits take in the brain, the
nerves, and tbe muscles ; in the same way as the movement of a watch
is produced by notbing but the force of its spring and the figure of its
wheels and other parts.

Descartes's " Treatise on Man " is a sketch of human physiology, in
wbich a bold attempt is made to explain all tbe phenomena of life, ex-
cept those of consciousness, by physical reasonings. To a mind turned
in this direction, Harvey's exposition of the heart and vessels as an
hydraulic mechanism must have been supremely welcome.

Descartes was not a mere philosophical theorist, but a bard-working
dissector and experimenter, and be held the strongest opinion respect-

VOL. XIX. — 61


ing the practical value of the new conception which he was introduc-
ing. He speaks of the importance of preserving health, and of the
dependence of the mind on the body being so close that perhaps the
only way of making men wiser and better than they are is to be sought
in medical science. " It is true," says he, " that as medicine is now
practiced, it contains little that is very useful ; but, without any desire
to depreciate, I am sure that there is no one, even among professional
men, who will not declare that all we know is very little as compared
with that which remains to be known ; and that we might escape an
infinity of diseases of the mind, no less than of the body, and even
perhaps from the weakness of old age, if we had sufficient knowledge
of their causes, and of all the remedies with which nature has provided
us." * So strongly impressed was Descartes with this, that he resolved
to spend the rest of his life in trying to acquire such a knowledge of
nature as would lead to the construction of a better medical doctrine. f
The anti-Cartesians found material for cheap ridicule in these aspira-
tions of the philosopher : and it is almost needless to say that, in the
thirteen years which elapsed between the publication of the "Dis-
cours " and the death of Descartes, he did not contribute much to their
realization. But, for the next century, all progress in physiology took
place along the lines which Descartes laid down.

The greatest physiological and j^athological work of the seventeenth
century, Borelli's treatise " De motu animalium," is, to all intents and
purposes, a development of Descartes's fundamental conception ; and
the same may be said of the physiology and pathology of Boerhaave,
whose authority dominated in the medical world of the first half of the
eighteenth century.

With the origin of modern chemistry and of electrical science in
the latter half of the eighteenth century, aids in the analysis of the
phenomena of life, of which Descartes could not have dreamed, were
offered to the physiologist. And the greater part of the gigantic prog-
ress which has been made in the present century, is a justification of
the prevision of Descartes. For it consists, essentially, in a more and
more complete resolution of the grosser organs of the living body into
physico-chemical mechanisms.

" I shall try to explain our whole bodily machinery in such a way
that it will be no more necessary for us to suppose that the soul pro-
duces such movements as are not voluntary than it is to think that
there is in a clock a soul which causes it to show the hours." J These
words of Descartes might be appropriately taken as a motto by the
author of any modern treatise on physiology.

But, though, as I think, there is no doubt that Descartes was the
first to propound the fundamental conception of the living body as a
physical mechanism, which is the distinctive feature of modern as

* "Discours de la Methode," 6e partie, Ed. Cousin, p. 193. \ Ibid., pp. 193, 211.

Online LibraryD. S. (David Samuel) MargoliouthThe Popular science monthly (Volume 19) → online text (page 100 of 110)