vision, and involved for a long time in great obscurity, is that of the
adjustment of the eye to different distances. Dr. Clay Wallace of New
York, who published a very ingenious little book on the eye about twenty
years ago, with vignettes reminding one of Bewick, was among the first,
if not the first, to describe the ciliary muscle, to which the power of
adjustment is generally ascribed. It is ascertained, by exact experiment
with the phacueidoscope, that accommodation depends on change of form of
the crystalline lens. Where the crystalline is wanting, as Mr. Ware long
ago taught, no power of accommodation remains. The ciliary muscle is
generally thought to effect the change of form of the crystalline. The
power of accommodation is lost after the application of atropine, in
consequence, as is supposed, of the paralysis of this muscle. This,
I believe, is the nearest approach to a demonstration we have on this
point.
I have only time briefly to refer to Professor Draper's most ingenious
theory as to the photographic nature of vision, for an account of which
I must refer to his original and interesting Treatise on Physiology.
It were to be wished that the elaborate and very interesting researches
of the Marquis Corti, which have revealed such singular complexity
of structure in the cochlea of the ear, had done more to clear up its
doubtful physiology; but I am afraid we have nothing but hypotheses for
the special part it plays in the act of hearing, and that we must say
the same respecting the office of the semicircular canals.
The microscope has achieved some of its greatest triumphs in teaching
us the changes which occur in the development of the embryo. No more
interesting discovery stands recorded in the voluminous literature
of this subject than the one originally announced by Martin Barry,
afterwards discredited, and still later confirmed by Mr. Newport and
others; namely the fact that the fertilizing filament reaches the
interior of the ovum in various animals;--a striking parallel to the
action of the pollen-tube in the vegetable. But beyond the mechanical
facts all is mystery in the movements of organization, as profound as in
the fall of a stone or the formation of a crystal.
To the chemist and the microscopist the living body presents the same
difficulties, arising from the fact that everything is in perpetual
change in the organism. The fibrine of the blood puzzles the one as much
as its globules puzzle the other. The difference between the branches of
science which deal with space only, and those which deal with space and
time, is this: we have no glasses that can magnify time. The figure I
here show you a was photographed from an object (pleurosigma angulatum)
magnified a thousand diameters, or presenting a million times its
natural surface. This other figure of the same object, enlarged from
the one just shown, is magnified seven thousand diameters, or forty-nine
million times in surface. When we can make the forty-nine millionth of
a second as long as its integer, physiology and chemistry will approach
nearer the completeness of anatomy.
Our reverence becomes more worthy, or, if you will, less unworthy of its
Infinite Object in proportion as our intelligence is lifted and expanded
to a higher and broader understanding of the Divine methods of action.
If Galen called his heathen readers to admire, the power, the wisdom,
the providence, the goodness of the “Framer of the animal body,”--if Mr.
Boyle, the student of nature, as Addison and that friend of his who had
known him for forty years tell us, never uttered the name of the Supreme
Being without making a distinct pause in his speech, in token of his
devout recognition of its awful meaning,--surely we, who inherit the
accumulated wisdom of nearly two hundred years since the time of
the British philosopher, and of almost two thousand since the Greek
physician, may well lift our thoughts from the works we study to their
great Artificer. These wonderful discoveries which we owe to that mighty
little instrument, the telescope of the inner firmament with all
its included worlds; these simple formulae by which we condense the
observations of a generation in a single axiom; these logical analyses
by which we fence out the ignorance we cannot reclaim, and fix the
limits of our knowledge,--all lead us up to the inspiration of the
Almighty, which gives understanding to the world's great teachers. To
fear science or knowledge, lest it disturb our old beliefs, is to fear
the influx of the Divine wisdom into the souls of our fellow-men; for
what is science but the piecemeal revelation,--uncovering,--of the plan
of creation, by the agency of those chosen prophets of nature whom God
has illuminated from the central light of truth for that single purpose?
The studies which we have glanced at are preliminary in your
education to the practical arts which make use of them,--the arts of
healing,--surgery and medicine. The more you examine the structure of
the organs and the laws of life, the more you will find how resolutely
each of the cell-republics which make up the E pluribus unum of the body
maintains its independence. Guard it, feed it, air it, warm it, exercise
or rest it properly, and the working elements will do their best to keep
well or to get well. What do we do with ailing vegetables? Dr. Warren,
my honored predecessor in this chair, bought a country-place, including
half of an old orchard. A few years afterwards I saw the trees on his
side of the fence looking in good health, while those on the other side
were scraggy and miserable. How do you suppose this change was brought
about? By watering them with Fowler's solution? By digging in calomel
freely about their roots? Not at all; but by loosening the soil
round them, and supplying them with the right kind of food in fitting
quantities.
Now a man is not a plant, or, at least, he is a very curious one, for
he carries his soil in his stomach, which is a kind--of portable
flower-pot, and he grows round it, instead of out of it. He has,
besides, a singularly complex nutritive apparatus and a nervous system.
But recollect the doctrine already enunciated in the language of
Virchow, that an animal, like a tree, is a sum of vital unities, of
which the cell is the ultimate element. Every healthy cell, whether in
a vegetable or an animal, necessarily performs its function properly
so long as it is supplied with its proper materials and stimuli. A cell
may, it is true, be congenitally defective, in which case disease is,
so to speak, its normal state. But if originally sound and subsequently
diseased, there has certainly been some excess, deficiency, or wrong
quality in the materials or stimuli applied to it. You remove this
injurious influence and substitute a normal one; remove the baked
coal-ashes, for instance, from the roots of a tree, and replace them
with loam; take away the salt meat from the patient's table, and replace
it with fresh meat and vegetables, and the cells of the tree or the man
return to their duty.
I do not know that we ever apply to a plant any element which is not
a natural constituent of the vegetable structure, except perhaps
externally, for the accidental purpose of killing parasites. The whole
art of cultivation consists in learning the proper food and conditions
of plants, and supplying them. We give them water, earths, salts of
various kinds such as they are made of, with a chance to help themselves
to air and light. The farmer would be laughed at who undertook to
manure his fields or his trees with a salt of lead or of arsenic. These
elements are not constituents of healthy plants. The gardener uses the
waste of the arsenic furnaces to kill the weeds in his walks.
If the law of the animal cell, and of the animal organism, which is
built up of such cells, is like that of the vegetable, we might expect
that we should treat all morbid conditions of any of the vital unities
belonging to an animal in the same way, by increasing, diminishing, or
changing its natural food or stimuli.
That is an aliment which nourishes; whatever we find in the organism, as
a constant and integral element, either forming part of its structure,
or one of the conditions of vital processes, that and that only deserves
the name of aliment. I see no reason, therefore, why iron, phosphate of
lime, sulphur, should not be considered food for man, as much as guano
or poudrette for vegetables. Whether one or another of them is best in
any given case,--whether they shall be taken alone or in combination, in
large or small quantities, are separate questions. But they are elements
belonging to the body, and even in moderate excess will produce little
disturbance. There is no presumption against any of this class of
substances, any more than against water or salt, provided they are used
in fitting combinations, proportions, and forms.
But when it comes to substances alien to the healthy system, which never
belong to it as normal constituents, the case is very different. There
is a presumption against putting lead or arsenic into the human body, as
against putting them into plants, because they do not belong there,
any more than pounded glass, which, it is said, used to be given as a
poison. The same thing is true of mercury and silver. What becomes of
these alien substances after they get into the system we cannot always
tell. But in the case of silver, from the accident of its changing color
under the influence of light, we do know what happens. It is thrown
out, in part at least, under the epidermis, and there it remains to the
patient's dying day. This is a striking illustration of the difficulty
which the system finds in dealing with non-assimilable elements, and
justifies in some measure the vulgar prejudice against mineral poisons.
I trust the youngest student on these benches will not commit the
childish error of confounding a presumption against a particular class
of agents with a condemnation of them. Mercury, for instance, is alien
to the system, and eminently disturbing in its influence. Yet its
efficacy in certain forms of specific disease is acknowledged by all
but the most sceptical theorists. Even the esprit moqueur of Ricord,
the Voltaire of pelvic literature, submits to the time-honored
constitutional authority of this great panacea in the class of cases
to which he has devoted his brilliant intelligence. Still, there is
no telling what evils have arisen from the abuse of this mineral.
Dr. Armstrong long ago pointed out some of them, and they have become
matters of common notoriety. I am pleased, therefore, when I find so
able and experienced a practitioner as Dr. Williams of this city proving
that iritis is best treated without mercury, and Dr. Vanderpoel showing
the same thing to be true for pericarditis.
Whatever elements nature does not introduce into vegetables, the
natural food of all animal life,--directly of herbivorous, indirectly of
carnivorous animals,--are to be regarded with suspicion. Arsenic-eating
may seem to improve the condition of horses for a time,--and even of
human beings, if Tschudi's stories can be trusted,--but it soon appears
that its alien qualities are at war with the animal organization. So of
copper, antimony, and other non-alimentary simple substances; everyone
of them is an intruder in the living system, as much as a constable
would be, quartered in our household. This does not mean that they may
not, any of them, be called in for a special need, as we send for the
constable when we have good reason to think we have a thief under our
roof; but a man's body is his castle, as well as his house, and the
presumption is that we are to keep our alimentary doors bolted against
these perturbing agents.
Now the feeling is very apt to be just contrary to this. The habit has
been very general with well-taught practitioners, to have recourse to
the introduction of these alien elements into the system on the occasion
of any slight disturbance. The tongue was a little coated, and mercury
must be given; the skin was a little dry, and the patient must take
antimony. It was like sending for the constable and the posse comitatus
when there is only a carpet to shake or a refuse-barrel to empty. [Dr.
James Johnson advises persons not ailing to take five grains of blue
pill with one or two of aloes twice a week for three or four months in
the year, with half a pint of compound decoction of sarsaparilla every
day for the same period, to preserve health and prolong life. Pract.
Treatise on Dis. of Liver, etc. p. 272.] The constitution bears slow
poisoning a great deal better than might be expected; yet the most
intelligent men in the profession have gradually got out of the habit of
prescribing these powerful alien substances in the old routine way.
Mr. Metcalf will tell you how much more sparingly they are given by our
practitioners at the present time, than when he first inaugurated
the new era of pharmacy among us. Still, the presumption in favor of
poisoning out every spontaneous reaction of outraged nature is
not extinct in those who are trusted with the lives of their
fellow-citizens. “On examining the file of prescriptions at the
hospital, I discovered that they were rudely written, and indicated a
treatment, as they consisted chiefly of tartar emetic, ipecacuanha, and
epsom salts, hardly favorable to the cure of the prevailing diarrhoea
and dysenteries.” In a report of a poisoning case now on trial, where we
are told that arsenic enough was found in the stomach to produce death
in twenty-four hours, the patient is said to have been treated by
arsenic, phosphorus, bryonia, aconite, nux vomica, and muriatic
acid,--by a practitioner of what school it may be imagined.
The traditional idea of always poisoning out disease, as we smoke out
vermin, is now seeking its last refuge behind the wooden cannon and
painted port-holes of that unblushing system of false scientific
pretences which I do not care to name in a discourse addressed to an
audience devoted to the study of the laws of nature in the light of the
laws of evidence. It is extraordinary to observe that the system which,
by its reducing medicine to a name and a farce, has accustomed all who
have sense enough to see through its thin artifices to the idea that
diseases get well without being “cured,” should now be the main support
of the tottering poison-cure doctrine. It has unquestionably helped
to teach wise people that nature heals most diseases without help from
pharmaceutic art, but it continues to persuade fools that art can arrest
them all with its specifics.
It is worse than useless to attempt in any way to check the freest
expression of opinion as to the efficacy of any or all of the “heroic”
means of treatment employed by practitioners of different schools and
periods. Medical experience is a great thing, but we must not forget
that there is a higher experience, which tries its results in a court
of a still larger jurisdiction; that, namely, in which the laws of human
belief are summoned to the witness-box, and obliged to testify to the
sources of error which beset the medical practitioner. The verdict is as
old as the father of medicine, who announces it in the words, “judgment
is difficult.” Physicians differed so in his time, that some denied that
there was any such thing as an art of medicine.
One man's best remedies were held as mischievous by another. The art of
healing was like soothsaying, so the common people said; “the same bird
was lucky or unlucky, according as he flew to the right or left.”
The practice of medicine has undergone great changes within the period
of my own observation. Venesection, for instance, has so far gone out
of fashion, that, as I am told by residents of the New York Bellevue
and the Massachusetts General Hospitals, it is almost obsolete in
these institutions, at least in medical practice. The old Brunonian
stimulating treatment has come into vogue again in the practice of Dr.
Todd and his followers. The compounds of mercury have yielded their
place as drugs of all work, and specifics for that very frequent
subjective complaint, nescio quid faciam,--to compounds of iodine. [Sir
Astley Cooper has the boldness,--or honesty,--to speak of medicines
which “are given as much to assist the medical man as his patient.”
Lectures (London, 1832), p. 14.] Opium is believed in, and quinine,
and “rum,” using that expressive monosyllable to mean all alcoholic
cordials. If Moliere were writing now, instead of saignare, purgare,
and the other, he would be more like to say, Stimulare, opium dare et
potassio-iodizare.
I have been in relation successively with the English and American
evacuant and alterative practice, in which calomel and antimony figured
so largely that, as you may see in Dr. Jackson's last “Letter,” Dr.
Holyoke, a good representative of sterling old-fashioned medical art,
counted them with opium and Peruvian bark as his chief remedies; with
the moderately expectant practice of Louis; the blood-letting “coup
sur coup” of Bouillaud; the contra-stimulant method of Rasori and his
followers; the anti-irritant system of Broussais, with its leeching
and gum-water; I have heard from our own students of the simple opium
practice of the renowned German teacher, Oppolzer; and now I find the
medical community brought round by the revolving cycle of opinion to
that same old plan of treatment which John Brown taught in Edinburgh
in the last quarter of the last century, and Miner and Tully fiercely
advocated among ourselves in the early years of the present. The
worthy physicians last mentioned, and their antagonist Dr. Gallup, used
stronger language than we of these degenerate days permit ourselves.
“The lancet is a weapon which annually slays more than the sword,” says
Dr. Tully. “It is probable that, for forty years past, opium and
its preparations have done seven times the injury they have rendered
benefit, on the great scale of the world,” says Dr. Gallup.
What is the meaning of these perpetual changes and conflicts of medical
opinion and practice, from an early antiquity to our own time? Simply
this: all “methods” of treatment end in disappointment of those
extravagant expectations which men are wont to entertain of medical art.
The bills of mortality are more obviously affected by drainage, than by
this or that method of practice. The insurance companies do not commonly
charge a different percentage on the lives of the patients of this or
that physician. In the course of a generation, more or less, physicians
themselves are liable to get tired of a practice which has so little
effect upon the average movement of vital decomposition. Then they are
ready for a change, even if it were back again to a method which has
already been tried, and found wanting.
Our practitioners, or many of them, have got back to the ways of old Dr.
Samuel Danforth, who, as it is well known, had strong objections to
the use of the lancet. By and by a new reputation will be made by some
discontented practitioner, who, tired of seeing patients die with their
skins full of whiskey and their brains muddy with opium, returns to a
bold antiphlogistic treatment, and has the luck to see a few patients
of note get well under it. So of the remedies which have gone out of
fashion and been superseded by others. It can hardly be doubted that
they will come into vogue again, more or less extensively, under the
influence of that irresistible demand for change just referred to.
Then will come the usual talk about a change in the character
of disease, which has about as much meaning as that concerning
“old-fashioned snow-storms.” “Epidemic constitutions” of disease mean
something, no doubt; a great deal as applied to malarious affections;
but that the whole type of diseases undergoes such changes that the
practice must be reversed from depleting to stimulating, and vice versa,
is much less likely than that methods of treatment go out of fashion and
come in again. If there is any disease which claims its percentage with
reasonable uniformity, it is phthisis. Yet I remember that the reverend
and venerable Dr. Prince of Salem told me one Commencement day, as I was
jogging along towards Cambridge with him, that he recollected the time
when that disease was hardly known; and in confirmation of his
statement mentioned a case in which it was told as a great event, that
somebody down on “the Cape” had died of “a consumption.” This story does
not sound probable to myself, as I repeat it, yet I assure you it is
true, and it shows how cautiously we must receive all popular stories of
great changes in the habits of disease.
Is there no progress, then, but do we return to the same beliefs and
practices which our forefathers wore out and threw away? I trust and
believe that there is a real progress. We may, for instance, return in
a measure to the Brunonian stimulating system, but it must be in a
modified way, for we cannot go back to the simple Brunonian pathology,
since we have learned too much of diseased action to accept its
convenient dualism. So of other doctrines, each new Avatar strips them
of some of their old pretensions, until they take their fitting place
at last, if they have any truth in them, or disappear, if they were mere
phantasms of the imagination.
In the mean time, while medical theories are coming in and going out,
there is a set of sensible men who are never run away with by them, but
practise their art sagaciously and faithfully in much the same way from
generation to generation. From the time of Hippocrates to that of our
own medical patriarch, there has been an apostolic succession of wise
and good practitioners. If you will look at the first aphorism of the
ancient Master you will see that before all remedies he places the
proper conduct of the patient and his attendants, and the fit ordering
of all the conditions surrounding him. The class of practitioners I have
referred to have always been the most faithful in attending to these
points. No doubt they have sometimes prescribed unwisely, in compliance
with the prejudices of their time, but they have grown wiser as they
have grown older, and learned to trust more in nature and less in their
plans of interference. I believe common opinion confirms Sir James
Clark's observation to this effect.
The experience of the profession must, I think, run parallel with that
of the wisest of its individual members. Each time a plan of treatment
or a particular remedy comes up for trial, it is submitted to a sharper
scrutiny. When Cullen wrote his Materia Medica, he had seriously to
assail the practice of giving burnt toad, which was still countenanced
by at least one medical authority of note. I have read recently in some
medical journal, that an American practitioner, whose name is known to
the country, is prescribing the hoof of a horse for epilepsy. It was
doubtless suggested by that old fancy of wearing a portion of elk's hoof
hung round the neck or in a ring, for this disease. But it is hard
to persuade reasonable people to swallow the abominations of a former
period. The evidence which satisfied Fernelius will not serve one of our
hospital physicians.
In this way those articles of the Materia Medica which had nothing but
loathsomeness to recommend them have been gradually dropped, and are not
like to obtain any general favor again with civilized communities. The
next culprits to be tried are the poisons. I have never been in the
least sceptical as to the utility of some of them, when properly
employed. Though I believe that at present, taking the world at large,
and leaving out a few powerful agents of such immense value that they
rank next to food in importance, the poisons prescribed for disease do
more hurt than good, I have no doubt, and never professed to have any,
that they do much good in prudent and instructed hands. But I am very
willing to confess a great jealousy of many agents, and I could almost
wish to see the Materia Medica so classed as to call suspicion upon
certain ones among them.
Thus the alien elements, those which do not properly enter into
the composition of any living tissue, are the most to be suspected,
--mercury, lead, antimony, silver, and the rest, for the reasons I have
before mentioned. Even iodine, which, as it is found in certain plants,
seems less remote from the animal tissues, gives unequivocal proofs
from time to time that it is hostile to some portions of the glandular
system.