The Complete PG Works of Oliver Wendell Holmes, Sr.

O >> Oliver Wendell Holmes, Sr. (The Physician and Poet not the Jurist) >> The Complete PG Works of Oliver Wendell Holmes, Sr.


"Thou art not thyself;
For thou exist'st on many a thousand grains
That issue out of dust."

If it is true that we understand ourselves but imperfectly in health,
this truth is more signally manifested in disease, where natural actions
imperfectly understood, disturbed in an obscure way by half-seen causes,
are creeping and winding along in the dark toward their destined issue,
sometimes using our remedies as safe stepping-stones, occasionally, it
may be, stumbling over them as obstacles.

I propose in this lecture to show you some points of contact between our
ignorance and our knowledge in several of the branches upon the study of
which you are entering. I may teach you a very little directly, but I
hope much more from the trains of thought I shall suggest. Do not expect
too much ground to be covered in this rapid survey. Our task is only
that of sending out a few pickets under the starry flag of science to the
edge of that dark domain where the ensigns of the obstinate rebel,
Ignorance, are flying undisputed. We are not making a reconnoissance in
force, still less advancing with the main column. But here are a few
roads along which we have to march together, and we wish to see clearly
how far our lines extend, and where the enemy's outposts begin.

Before touching the branches of knowledge that deal with organization and
vital functions, let us glance at that science which meets you at the
threshold of your study, and prepares you in some measure to deal with
the more complex problems of the living laboratory.

CHEMISTRY. includes the art of separating and combining the elements of
matter, and the study of the changes produced by these operations. We can
hardly say too much of what it has contributed to our knowledge of the
universe and our power of dealing with its materials. It has given us a
catalogue raisonne of the substances found upon our planet, and shown how
everything living and dead is put together from them. It is
accomplishing wonders before us every day, such as Arabian story-tellers
used to string together in their fables. It spreads the, sensitive film
on the artificial retina which looks upon us through the optician's lens
for a few seconds, and fixes an image that will outlive its original. It
questions the light of the sun, and detects the vaporized metals floating
around the great luminary,--iron, sodium, lithium, and the rest,--as if
the chemist of our remote planet could fill his bell-glasses from its
fiery atmosphere. It lends the power which flashes our messages in
thrills that leave the lazy chariot of day behind them. It seals up a
few dark grains in iron vases, and lo! at the touch of a single spark,
rises in smoke and flame a mighty Afrit with a voice like thunder and an
arm that shatters like an earthquake. The dreams of Oriental fancy have
become the sober facts of our every-day life, and the chemist is the
magician to whom we owe them.

To return to the colder scientific aspect of chemistry. It has shown us
how bodies stand affected to each other through an almost boundless range
of combinations. It has given us a most ingenious theory to account for
certain fixed relations in these combinations. It has successfully
eliminated a great number of proximate compounds, more or less stable,
from organic structures. It has invented others which form the basis of
long series of well-known composite substances. In fact, we are perhaps
becoming overburdened with our list of proximate principles, demonstrated
and hypothetical.

How much nearer have we come to the secret of force than Lully and Geber
and the whole crew of juggling alchemists? We have learned a great deal
about the how, what have we learned about the why?

Why does iron rust, while gold remains untarnished, and gold amalgamate,
while iron refuses the alliance of mercury?

The alchemists called gold Sol, the sun, and iron Mars, and pleased
themselves with fancied relations between these substances and the
heavenly bodies, by which they pretended to explain the facts they
observed. Some of their superstitions have lingered in practical
medicine to the present day, but chemistry has grown wise enough to
confess the fact of absolute ignorance.

What is it that makes common salt crystallize in the form of cubes, and
saltpetre in the shape of six-sided prisms? We see no reason why it
should not have been just the other way, salt in prisms and saltpetre in
cubes, or why either should take an exact geometrical outline, any more
than coagulating albumen.

But although we had given up attempting to explain the essential nature
of affinities and of crystalline types, we might have supposed that we
had at least fixed the identity of the substances with which we deal, and
determined the laws of their combination. All at once we find that a
simple substance changes face, puts off its characteristic qualities and
resumes them at will;--not merely when we liquefy or vaporize a solid, or
reverse the process; but that a solid is literally transformed into
another solid under our own eyes. We thought we knew phosphorus. We warm
a portion of it sealed in an empty tube, for about a week. It has become
a brown infusible substance, which does not shine in the dark nor oxidate
in the air. We heat it to 500 F., and it becomes common phosphorus again.
We transmute sulphur in the same singular way. Nature, you know, gives
us carbon in the shape of coal and in that of the diamond. It is easy to
call these changes by the name allotropism, but not the less do they
confound our hasty generalizations.

These facts of allotropism have some corollaries connected with them
rather startling to us of the nineteenth century. There may be other
transmutations possible besides those of phosphorus and sulphur. When Dr.
Prout, in 1840, talked about azote and carbon being "formed" in the
living system, it was looked upon as one of those freaks of fancy to
which philosophers, like other men, are subject. But when Professor
Faraday, in 1851, says, at a meeting of the British Association, that
"his hopes are in the direction of proving that bodies called simple were
really compounds, and may be formed artificially as soon as we are
masters of the laws influencing their combinations,"--when he comes
forward and says that he has tried experiments at transmutation, and
means, if his life is spared, to try them again,--how can we be surprised
at the popular story of 1861, that Louis Napoleon has established a
gold-factory and is glutting the mints of Europe with bullion of his own
making?

And so with reference to the law of combinations. The old maxim was,
Corpora non agunt nisi soluta. If two substances, a and b, are inclosed
in a glass vessel, c, we do not expect the glass to change them, unless a
or b or the compound a b has the power of dissolving the glass. But if
for a I take oxygen, for b hydrogen, and for c a piece of spongy
platinum, I find the first two combine with the common signs of
combustion and form water, the third in the mean time undergoing no
perceptible change. It has played the part of the unwedded priest, who
marries a pair without taking a fee or having any further relation with
the parties. We call this catalysis, catalytic action, the action of
presence, or by what learned name we choose. Give what name to it we
will, it is a manifestation of power which crosses our established laws
of combination at a very open angle of intersection. I think we may find
an analogy for it in electrical induction, the disturbance of the
equilibrium of the electricity of a body by the approach of a charged
body to it, without interchange of electrical conditions between the two
bodies. But an analogy is not an explanation, and why a few drops of
yeast should change a saccharine mixture to carbonic acid and alcohol,--a
little leaven leavening the whole lump,--not by combining with it, but by
setting a movement at work, we not only cannot explain, but the fact is
such an exception to the recognized laws of combination that Liebig is
unwilling to admit the new force at all to which Berzelius had given the
name so generally accepted.

The phenomena of isomerism, or identity of composition and proportions of
constituents with difference of qualities, and of isomorphism, or
identity of form in crystals which have one element substituted for
another, were equally surprises to science; and although the mechanism by
which they are brought about can be to a certain extent explained by a
reference to the hypothetical atoms of which the elements are
constituted, yet this is only turning the difficulty into a fraction with
an infinitesimal denominator and an infinite numerator.

So far we have studied the working of force and its seeming anomalies in
purely chemical phenomena. But we soon find that chemical force is
developed by various other physical agencies,--by heat, by light, by
electricity, by magnetism, by mechanical agencies; and, vice versa, that
chemical action develops heat, light, electricity, magnetism, mechanical
force, as we see in our matches, galvanic batteries, and explosive
compounds. Proceeding with our experiments, we find that every kind of
force is capable of producing all other kinds, or, in Mr. Faraday's
language, that "the various forms under which the forces of matter are
made manifest have a common origin, or, in other words, are so directly
related and mutually dependent that they are convertible one into
another."

Out of this doctrine naturally springs that of the conservation of force,
so ably illustrated by Mr. Grove, Dr. Carpenter, and Mr. Faraday. This
idea is no novelty, though it seems so at first sight. It was maintained
and disputed among the giants of philosophy. Des Cartes and Leibnitz
denied that any new motion originated in nature, or that any ever ceased
to exist; all motion being in a circle, passing from one body to another,
one losing what the other gained. Newton, on the other hand, believed
that new motions were generated and existing ones destroyed. On the
first supposition, there is a fixed amount of force always circulating in
the universe. On the second, the total amount may be increasing or
diminishing. You will find in the "Annual of Scientific Discovery" for
1858 a very interesting lecture by Professor Helmholtz of Bonn, in which
it is maintained that a certain portion of force is lost in every natural
process, being converted into unchangeable heat, so that the universe
will come to a stand-still at last, all force passing into heat, and all
heat into a state of equilibrium.

The doctrines of the convertibility or specific equivalence of the
various forms of force, and of its conservation, which is its logical
consequence, are very generally accepted, as I believe, at the present
time, among physicists. We are naturally led to the question, What is
the nature of force? The three illustrious philosophers just referred to
agree in attributing the general movements of the universe to the
immediate Divine action. The doctrine of "preestablished harmony" was an
especial contrivance of Leibnitz to remove the Creator from unworthy
association with the less divine acts of living beings. Obsolete as this
expression sounds to our ears, the phrase laws of the universe, which we
use so constantly with a wider application, appears to me essentially
identical with it.

Force does not admit of explanation, nor of proper definition, any more
than the hypothetical substratum of matter. If we assume the Infinite as
omnipresent, omniscient, omnipotent, we cannot suppose Him excluded from
any part of His creation, except from rebellious souls which voluntarily
exclude Him by the exercise of their fatal prerogative of free-will.
Force, then, is the act of immanent Divinity. I find no meaning in
mechanical explanations. Newton's hypothesis of an ether filling the
heavenly spaces does not, I confess, help my conceptions. I will, and
the muscles of my vocal organs shape my speech. God wills, and the
universe articulates His power, wisdom, and goodness. That is all I
know. There is no bridge my mind can throw from the "immaterial" cause
to the "material" effect.

The problem of force meets us everywhere, and I prefer to encounter it in
the world of physical phenomena before reaching that of living actions.
It is only the name for the incomprehensible cause of certain changes
known to our consciousness, and assumed to be outside of it. For me it
is the Deity Himself in action.

I can therefore see a large significance in the somewhat bold language of
Burdach: "There is for me but one miracle, that of infinite existence,
and but one mystery, the manner in which the finite proceeds from the
infinite. So soon as we recognize this incomprehensible act as the
general and primordial miracle, of which our reason perceives the
necessity, but the manner of which our intelligence cannot grasp, so soon
as we contemplate the nature known to us by experience in this light,
there is for us no other impenetrable miracle or mystery."

Let us turn to a branch of knowledge which deals with certainties up to
the limit of the senses, and is involved in no speculations beyond them.
In certain points of view, HUMAN ANATOMY may be considered an almost
exhausted science. From time to time some small organ which had escaped
earlier observers has been pointed out,--such parts as the tensor tarsi,
the otic ganglion, or the Pacinian bodies; but some of our best
anatomical works are those which have been classic for many generations.
The plates of the bones in Vesalius, three centuries old, are still
masterpieces of accuracy, as of art. The magnificent work of Albinus on
the muscles, published in 1747, is still supreme in its department, as
the constant references of the most thorough recent treatise on the
subject, that of Theile, sufficiently show. More has been done in
unravelling the mysteries of the fasciae, but there has been a tendency
to overdo this kind of material analysis. Alexander Thomson split them
up into cobwebs, as you may see in the plates to Velpeau's Surgical
Anatomy. I well remember how he used to shake his head over the coarse
work of Scarpa and Astley Cooper,--as if Denner, who painted the separate
hairs of the beard and pores of the skin in his portraits, had spoken
lightly of the pictures of Rubens and Vandyk.

Not only has little been added to the catalogue of parts, but some things
long known had become half-forgotten. Louis and others confounded the
solitary glands of the lower part of the small intestine with those which
"the great Brunner," as Haller calls him, described in 1687 as being
found in the duodenum. The display of the fibrous structure of the brain
seemed a novelty as shown by Spurzheim. One is startled to find the
method anticipated by Raymond Vieussens nearly two centuries ago. I can
hardly think Gordon had ever looked at his figures, though he names their
author, when he wrote the captious and sneering article which attracted
so much attention in the pages of the "Edinburgh Review."

This is the place, if anywhere, to mention any observations I could
pretend to have made in the course of my teaching the structure of the
human body. I can make no better show than most of my predecessors in
this well-reaped field. The nucleated cells found connected with the
cancellated structure of the bones, which I first pointed out and had
figured in 1847, and have shown yearly from that time to the present, and
the fossa masseterica, a shallow concavity on the ramus of the lower jaw,
for the lodgment of the masseter muscle, which acquires significance when
examined by the side of the deep cavity on the corresponding part in some
carnivora to which it answers, may perhaps be claimed as deserving
attention. I have also pleased myself by making a special group of the
six radiating muscles which diverge from the spine of the axis, or second
cervical vertebra, and by giving to it the name stella musculosa nuchaee.
But this scanty catalogue is only an evidence that one may teach long and
see little that has not been noted by those who have gone before him. Of
course I do not think it necessary to include rare, but already described
anomalies, such as the episternal bones, the rectus sternalis, and other
interesting exceptional formations I have encountered, which have shown a
curious tendency to present themselves several times in the same season,
perhaps because the first specimen found calls our attention to any we
may subsequently meet with.

The anatomy of the scalpel and the amphitheatre was, then, becoming an
exhausted branch of investigation. But during the present century the
study of the human body has changed its old aspect, and become fertile in
new observations. This rejuvenescence was effected by means of two
principal agencies,--new methods and a new instrument.

Descriptive anatomy, as known from an early date, is to the body what
geography is to the planet. Now geography was pretty well known so long
ago as when Arrowsmith, who was born in 1750, published his admirable
maps. But in that same year was born Werner, who taught a new way of
studying the earth, since become familiar to us all under the name of
Geology.

What geology has done for our knowledge of the earth, has been done for
our knowledge of the body by that method of study to which is given the
name of General Anatomy. It studies, not the organs as such, but the
elements out of which the organs are constructed. It is the geology of
the body, as that is the general anatomy of the earth. The extraordinary
genius of Bichat, to whom more than any other we owe this new method of
study, does not require Mr. Buckle's testimony to impress the
practitioner with the importance of its achievements. I have heard a
very wise physician question whether any important result had accrued to
practical medicine from Harvey's discovery of the circulation. But
Anatomy, Physiology, and Pathology have received a new light from this
novel method of contemplating the living structures, which has had a vast
influence in enabling the practitioner at least to distinguish and
predict the course of disease. We know as well what differences to
expect in the habits of a mucous and of a serous membrane, as what
mineral substances to look for in the chalk or the coal measures. You
have only to read Cullen's description of inflammation of the lungs or of
the bowels, and compare it with such as you may find in Laennec or
Watson, to see the immense gain which diagnosis and prognosis have
derived from general anatomy.

The second new method of studying the human structure, beginning with the
labors of Scarpa, Burns, and Colles, grew up principally during the first
third of this century. It does not deal with organs, as did the earlier
anatomists, nor with tissues, after the manner of Bichat. It maps the
whole surface of the body into an arbitrary number of regions, and
studies each region successively from the surface to the bone, or beneath
it. This hardly deserves the name of a science, although Velpeau has
dignified it with that title, but it furnishes an admirable practical way
for the surgeon who has to operate on a particular region of the body to
study that region. If we are buying a farm, we are not content with the
State map or a geological chart including the estate in question. We
demand an exact survey of that particular property, so that we may know
what we are dealing with. This is just what regional, or, as it is
sometimes called, surgical anatomy, does for the surgeon with reference
to the part on which his skill is to be exercised. It enables him to see
with the mind's eye through the opaque tissues down to the bone on which
they lie, as if the skin were transparent as the cornea, and the organs
it covers translucent as the gelatinous pulp of a medusa.

It is curious that the Japanese should have anticipated Europe in a kind
of rude regional anatomy. I have seen a manikin of Japanese make traced
all over with lines, and points marking their intersection. By this
their doctors are guided in the performance of acupuncture, marking the
safe places to thrust in needles, as we buoy out our ship-channels, and
doubtless indicating to learned eyes the spots where incautious meddling
had led to those little accidents of shipwreck to which patients are
unfortunately liable.

A change of method, then, has given us General and Regional Anatomy.
These, too, have been worked so thoroughly, that, if not exhausted, they
have at least become to a great extent fixed and positive branches of
knowledge. But the first of them, General Anatomy, would never, have
reached this positive condition but for the introduction of that,
instrument which I have mentioned as the second great aid to modern
progress.

This instrument is the achromatic microscope. For the history of the
successive steps by which it became the effective scientific implement we
now possess, I must refer you to the work of Mr. Quekett, to an excellent
article in the "Penny Cyclopaedia," or to that of Sir David Brewster in
the "Encyclopaedia Britannica." It is a most interesting piece of
scientific history, which shows how the problem which Biot in 1821
pronounced insolvable was in the course of a few years practically
solved, with a success equal to that which Dollond had long before
obtained with the telescope. It is enough for our purpose that we are
now in possession of an instrument freed from all confusions and
illusions, which magnifies a thousand diameters,--a million times in
surface,--without serious distortion or discoloration of its object.

A quarter of a century ago, or a little more, an instructor would not
have hesitated to put John Bell's "Anatomy" and Bostock's "Physiology"
into a student's hands, as good authority on their respective subjects.
Let us not be unjust to either of these authors. John Bell is the
liveliest medical writer that I can remember who has written since the
days of delightful old Ambroise Pare. His picturesque descriptions and
bold figures are as good now as they ever were, and his book can never
become obsolete. But listen to what John Bell says of the microscope:

"Philosophers of the last age had been at infinite pains to find the
ultimate fibre of muscles, thinking to discover its properties in its
form; but they saw just in proportion to the glasses which they used, or
to their practice and skill in that art, which is now almost forsaken."

Dr. Bostock's work, neglected as it is, is one which I value very highly
as a really learned compilation, full of original references. But Dr.
Bostock says: "Much as the naturalist has been indebted to the
microscope, by bringing into view many beings of which he could not
otherwise have ascertained the existence, the physiologist has not yet
derived any great benefit from the instrument."

These are only specimens of the manner in which the microscope and its
results were generally regarded by the generation just preceding our own.

I have referred you to the proper authorities for the account of those
improvements which about the year 1830 rendered the compound microscope
an efficient and trustworthy instrument. It was now for the first time
that a true general anatomy became possible. As early as 1816 Treviranus
had attempted to resolve the tissues, of which Bichat had admitted no
less than twenty-one, into their simple microscopic elements. How could
such an attempt succeed, Henle well asks, at a time when the most
extensively diffused of all the tissues, the areolar, was not at all
understood? All that method could do had been accomplished by Bichat and
his followers. It was for the optician to take the next step. The
future of anatomy and physiology, as an enthusiastic micrologist of the
time said, was in the hands of Messrs. Schieck and Pistor, famous
opticians of Berlin.

In those earlier days of which I am speaking, all the points of minute
anatomy were involved in obscurity. Some found globules everywhere, some
fibres. Students disputed whether the conjunctiva extended over the
cornea or not, and worried themselves over Gaultier de Claubry's
stratified layers of the skin, or Breschet's blennogenous and
chromatogenous organs. The dartos was a puzzle, the central spinal canal
a myth, the decidua clothed in fable as much as the golden fleece. The
structure of bone, now so beautifully made out,--even that of the teeth,
in which old Leeuwenhoek, peeping with his octogenarian eyes through the
minute lenses wrought with his own hands, had long ago seen the "pipes,"
as he called them,--was hardly known at all. The minute structure of the
viscera lay in the mists of an uncertain microscopic vision. The
intimate recesses of the animal system were to the students of anatomy
what the anterior of Africa long was to geographers, and the stories of
microscopic explorers were as much sneered at as those of Bruce or Du
Chailly, and with better reason.

Now what have we come to in our own day? In the first place, the minute
structure of all the organs has been made out in the most satisfactory
way. The special arrangements of the vessels and the ducts of all the
glands, of the air-tubes and vesicles of the lungs, of the parts which
make up the skin and other membranes, all the details of those complex
parenchymatous organs which had confounded investigation so long, have
been lifted out of the invisible into the sight of all observers. It is
fair to mention here, that we owe a great deal to the art of minute
injection, by which we are enabled to trace the smallest vessels in the
midst of the tissues where they are distributed. This is an old artifice
of anatomists. The famous Ruysch, who died a hundred and thirty years
ago, showed that each of the viscera has its terminal vessels arranged in
its own peculiar way; the same fact which you may see illustrated in
Gerber's figures after the minute injections of Berres. I hope to show
you many specimens of this kind in the microscope, the work of English
and American hands. Professor Agassiz allows me also to make use of a
very rich collection of injected preparations sent him by Professor
Hyrtl, formerly of Prague, now of Vienna, for the proper exhibition of
which I had a number of microscopes made expressly, by Mr. Grunow, during
the past season. All this illustrates what has been done for the
elucidation of the intimate details of formation of the organs.