EIGHTEENTH-CENTURY MEDICINE
THE SYSTEM OF BOERHAAVE
At least two pupils of William Harvey distinguished themselves in
medicine, Giorgio Baglivi (1669-1707), who has been called the
"Italian Sydenham," and Hermann Boerhaave (1668-1738). The work
of Baglivi was hardly begun before his early death removed one of
the most promising of the early eighteenth-century physicians.
Like Boerhaave, he represents a type of skilled, practical
clinitian rather than the abstract scientist. One of his
contributions to medical literature is the first accurate
description of typhoid, or, as he calls it, mesenteric fever.
If for nothing else, Boerhaave must always be remembered as the
teacher of Von Haller, but in his own day he was the widest known
and the most popular teacher in the medical world. He was the
idol of his pupils at Leyden, who flocked to his lectures in such
numbers that it became necessary to "tear down the walls of
Leyden to accommodate them." His fame extended not only all over
Europe but to Asia, North America, and even into South America.
A letter sent him from China was addressed to "Boerhaave in
Europe." His teachings represent the best medical knowledge of
his day, a high standard of morality, and a keen appreciation of
the value of observation; and it was through such teachings
imparted to his pupils and advanced by them, rather than to any
new discoveries, that his name is important in medical history.
His arrangement and classification of the different branches of
medicine are interesting as representing the attitude of the
medical profession towards these various branches at that time.
"In the first place we consider Life; then Health, afterwards
Diseases; and lastly their several Remedies.
"Health the first general branch of Physic in our Institutions is
termed Physiology, or the Animal Oeconomy; demonstrating the
several Parts of the human Body, with their Mechanism and
Actions.
"The second branch of Physic is called Pathology, treating of
Diseases, their Differences, Causes and Effects, or Symptoms; by
which the human Body is known to vary from its healthy state.
"The third part of Physic is termed Semiotica, which shows the
Signs distinguishing between sickness and Health, Diseases and
their Causes in the human Body; it also imports the State and
Degrees of Health and Diseases, and presages their future Events.
"The fourth general branch of Physic is termed Hygiene, or
Prophylaxis.
"The fifth and last part of Physic is called Therapeutica; which
instructs us in the Nature, Preparation and uses of the Materia
Medica; and the methods of applying the same, in order to cure
Diseases and restore lost Health."[1]
From this we may gather that his general view of medicine was not
unlike that taken at the present time.
Boerhaave's doctrines were arranged into a "system" by Friedrich
Hoffmann, of Halle (1660-1742), this system having the merit of
being simple and more easily comprehended than many others. In
this system forces were considered inherent in matter, being
expressed as mechanical movements, and determined by mass,
number, and weight. Similarly, forces express themselves in the
body by movement, contraction, and relaxation, etc., and life
itself is movement, "particularly movement of the heart." Life
and death are, therefore, mechanical phenomena, health is
determined by regularly recurring movements, and disease by
irregularity of them. The body is simply a large hydraulic
machine, controlled by "the aether" or "sensitive soul," and the
chief centre of this soul lies in the medulla.
In the practical application of medicines to diseases Hoffman
used simple remedies, frequently with happy results, for whatever
the medical man's theory may be he seldom has the temerity to
follow it out logically, and use the remedies indicated by his
theory to the exclusion of long-established, although perhaps
purely empirical, remedies. Consequently, many vague theorists
have been excellent practitioners, and Hoffman was one of these.
Some of the remedies he introduced are still in use, notably the
spirits of ether, or "Hoffman's anodyne."
ANIMISTS, VITALISTS, AND ORGANICISTS
Besides Hoffman's system of medicine, there were numerous others
during the eighteenth century, most of which are of no importance
whatever; but three, at least, that came into existence and
disappeared during the century are worthy of fuller notice. One
of these, the Animists, had for its chief exponent Georg Ernst
Stahl of "phlogiston" fame; another, the Vitalists, was
championed by Paul Joseph Barthez (1734-1806); and the third was
the Organicists. This last, while agreeing with the other two
that vital activity cannot be explained by the laws of physics
and chemistry, differed in not believing that life "was due to
some spiritual entity," but rather to the structure of the body
itself.
The Animists taught that the soul performed functions of ordinary
life in man, while the life of lower animals was controlled by
ordinary mechanical principles. Stahl supported this theory
ardently, sometimes violently, at times declaring that there were
"no longer any doctors, only mechanics and chemists." He denied
that chemistry had anything to do with medicine, and, in the
main, discarded anatomy as useless to the medical man. The soul,
he thought, was the source of all vital movement; and the
immediate cause of death was not disease but the direct action of
the soul. When through some lesion, or because the machinery of
the body has become unworkable, as in old age, the soul leaves
the body and death is produced. The soul ordinarily selects the
channels of the circulation, and the contractile parts, as the
route for influencing the body. Hence in fever the pulse is
quickened, due to the increased activity of the soul, and
convulsions and spasmodic movements in disease are due, to the,
same cause. Stagnation of the, blood was supposed to be a
fertile cause of diseases, and such diseases were supposed to
arise mostly from "plethora"--an all-important element in Stahl's
therapeutics. By many this theory is regarded as an attempt on
the part of the pious Stahl to reconcile medicine and theology in
a way satisfactory to both physicians and theologians, but, like
many conciliatory attempts, it was violently opposed by both
doctors and ministers.
A belief in such a theory would lead naturally to simplicity in
therapeutics, and in this respect at least Stahl was consistent.
Since the soul knew more about the body than any physician could
know, Stahl conceived that it would be a hinderance rather than a
help for the physician to interfere with complicated doses of
medicine. As he advanced in age this view of the administration
of drugs grew upon him, until after rejecting quinine, and
finally opium, he at last used only salt and water in treating
his patients. From this last we may judge that his "system," if
not doing much good, was at least doing little harm.
The theory of the Vitalists was closely allied to that of the
Animists, and its most important representative, Paul Joseph
Barthez, was a cultured and eager scientist. After an eventful
and varied career as physician, soldier, editor, lawyer, and
philosopher in turn, he finally returned to the field of
medicine, was made consulting physician by Napoleon in 1802, and
died in Paris four years later.
The theory that he championed was based on the assumption that
there was a "vital principle," the nature of which was unknown,
but which differed from the thinking mind, and was the cause of
the phenomena of life. This "vital principle" differed from the
soul, and was not exhibited in human beings alone, but even in
animals and plants. This force, or whatever it might be called,
was supposed to be present everywhere in the body, and all
diseases were the results of it.
The theory of the Organicists, like that of the Animists and
Vitalists, agreed with the other two that vital activity could
not be explained by the laws of physics and chemistry, but,
unlike them, it held that it was a part of the structure of the
body itself. Naturally the practical physicians were more
attracted by this tangible doctrine than by vague theories "which
converted diseases into unknown derangements of some equally
unknown 'principle.' "
It is perhaps straining a point to include this brief description
of these three schools of medicine in the history of the progress
of the science. But, on the whole, they were negatively at least
prominent factors in directing true progress along its proper
channel, showing what courses were not to be pursued. Some one
has said that science usually stumbles into the right course only
after stumbling into all the wrong ones; and if this be only
partially true, the wrong ones still play a prominent if not a
very creditable part. Thus the medical systems of William Cullen
(1710-1790), and John Brown (1735-1788), while doing little
towards the actual advancement of scientific medicine, played so
conspicuous a part in so wide a field that the "Brunonian system"
at least must be given some little attention.
According to Brown's theory, life, diseases, and methods of cure
are explained by the property of "excitability." All exciting
powers were supposed to be stimulating, the apparent debilitating
effects of some being due to a deficiency in the amount of
stimulus. Thus "the whole phenomena of life, health, as well as
disease, were supposed to consist of stimulus and nothing else."
This theory created a great stir in the medical world, and
partisans and opponents sprang up everywhere. In Italy it was
enthusiastically supported; in England it was strongly opposed;
while in Scotland riots took place between the opposing factions.
Just why this system should have created any stir, either for or
against it, is not now apparent.
Like so many of the other "theorists" of his century, Brown's
practical conclusions deduced from his theory (or perhaps in
spite of it) were generally beneficial to medicine, and some of
them extremely valuable in the treatment of diseases. He first
advocated the modern stimulant, or "feeding treatment" of fevers,
and first recognized the usefulness of animal soups and beef-tea
in certain diseases.
THE SYSTEM OF HAHNEMANN
Just at the close of the century there came into prominence the
school of homoeopathy, which was destined to influence the
practice of medicine very materially and to outlive all the other
eighteenth-century schools. It was founded by Christian Samuel
Friedrich Hahnemann (1755-1843), a most remarkable man, who,
after propounding a theory in his younger days which was at least
as reasonable as most of the existing theories, had the
misfortune to outlive his usefulness and lay his doctrine open to
ridicule by the unreasonable teachings of his dotage,
Hahnemann rejected all the teachings of morbid anatomy and
pathology as useless in practice, and propounded his famous
"similia similibus curantur"--that all diseases were to be cured
by medicine which in health produced symptoms dynamically similar
to the disease under treatment. If a certain medicine produced a
headache when given to a healthy person, then this medicine was
indicated in case of headaches, etc. At the present time such a
theory seems crude enough, but in the latter part of the
eighteenth century almost any theory was as good as the ones
propounded by Animists, Vitalists, and other such schools. It
certainly had the very commendable feature of introducing
simplicity in the use of drugs in place of the complicated
prescriptions then in vogue. Had Hahnemann stopped at this point
he could not have been held up to the indefensible ridicule that
was brought upon him, with considerable justice, by his later
theories. But he lived onto propound his extraordinary theory of
"potentiality"--that medicines gained strength by being
diluted--and his even more extraordinary theory that all chronic
diseases are caused either by the itch, syphilis, or fig-wart
disease, or are brought on by medicines.
At the time that his theory of potentialities was promulgated,
the medical world had gone mad in its administration of huge
doses of compound mixtures of drugs, and any reaction against
this was surely an improvement. In short, no medicine at all was
much better than the heaping doses used in common practice; and
hence one advantage, at least, of Hahnemann's methods. Stated
briefly, his theory was that if a tincture be reduced to
one-fiftieth in strength, and this again reduced to one-fiftieth,
and this process repeated up to thirty such dilutions, the
potency of such a medicine will be increased by each dilution,
Hahnemann himself preferring the weakest, or, as he would call
it, the strongest dilution. The absurdity of such a theory is
apparent when it is understood that long before any drug has been
raised to its thirtieth dilution it has been so reduced in
quantity that it cannot be weighed, measured, or recognized as
being present in the solution at all by any means known to
chemists. It is but just to modern followers of homoeopathy to
say that while most of them advocate small dosage, they do not
necessarily follow the teachings of Hahnemann in this respect,
believing that the theory of the dose "has nothing more to do
with the original law of cure than the psora (itch) theory has;
and that it was one of the later creations of Hahnemann's mind."
Hahnemann's theory that all chronic diseases are derived from
either itch, syphilis, or fig-wart disease is no longer advocated
by his followers, because it is so easily disproved, particularly
in the case of itch. Hahnemann taught that fully three-quarters
of all diseases were caused by "itch struck in," and yet it had
been demonstrated long before his day, and can be demonstrated
any time, that itch is simply a local skin disease caused by a
small parasite.
JENNER AND VACCINATION
All advances in science have a bearing, near or remote, on the
welfare of our race; but it remains to credit to the closing
decade of the eighteenth century a discovery which, in its power
of direct and immediate benefit to humanity, surpasses any other
discovery of this or any previous epoch. Needless to say, I refer
to Jenner's discovery of the method of preventing smallpox by
inoculation with the virus of cow-pox. It detracts nothing from
the merit of this discovery to say that the preventive power of
accidental inoculation had long been rumored among the peasantry
of England. Such vague, unavailing half-knowledge is often the
forerunner of fruitful discovery.
To all intents and purposes Jenner's discovery was original and
unique. Nor, considered as a perfect method, was it in any sense
an accident. It was a triumph of experimental science. The
discoverer was no novice in scientific investigation, but a
trained observer, who had served a long apprenticeship in
scientific observation under no less a scientist than the
celebrated John Hunter. At the age of twenty-one Jenner had gone
to London to pursue his medical studies, and soon after he proved
himself so worthy a pupil that for two years he remained a member
of Hunter's household as his favorite pupil. His taste for
science and natural history soon attracted the attention of Sir
Joseph Banks, who intrusted him with the preparation of the
zoological specimens brought back by Captain Cook's expedition in
1771. He performed this task so well that he was offered the
position of naturalist to the second expedition, but declined it,
preferring to take up the practice of his profession in his
native town of Berkeley.
His many accomplishments and genial personality soon made him a
favorite both as a physician and in society. He was a good
singer, a fair violinist and flute-player, and a very successful
writer of prose and verse. But with all his professional and
social duties he still kept up his scientific investigations,
among other things making some careful observations on the
hibernation of hedgehogs at the instigation of Hunter, the
results of which were laid before the Royal Society. He also
made quite extensive investigations as to the geological
formations and fossils found in his neighborhood.
Even during his student days with Hunter he had been much
interested in the belief, current in the rural districts of
Gloucestershire, of the antagonism between cow-pox and small-pox,
a person having suffered from cow-pox being immuned to small-pox.
At various times Jenner had mentioned the subject to Hunter, and
he was constantly making inquiries of his fellow-practitioners as
to their observations and opinions on the subject. Hunter was too
fully engrossed in other pursuits to give the matter much serious
attention, however, and Jenner's brothers of the profession gave
scant credence to the rumors, although such rumors were common
enough.
At this time the practice of inoculation for preventing
small-pox, or rather averting the severer forms of the disease,
was widely practised. It was customary, when there was a mild
case of the disease, to take some of the virus from the patient
and inoculate persons who had never had the disease, producing a
similar attack in them. Unfortunately there were many objections
to this practice. The inoculated patient frequently developed a
virulent form of the disease and died; or if he recovered, even
after a mild attack, he was likely to be "pitted" and disfigured.
But, perhaps worst of all, a patient so inoculated became the
source of infection to others, and it sometimes happened that
disastrous epidemics were thus brought about. The case was a
most perplexing one, for the awful scourge of small-pox hung
perpetually over the head of every person who had not already
suffered and recovered from it. The practice of inoculation was
introduced into England by Lady Mary Wortley Montague
(1690-1762), who had seen it practised in the East, and who
announced her intention of "introducing it into England in spite
of the doctors."
From the fact that certain persons, usually milkmaids, who had
suffered from cow-pox seemed to be immuned to small-pox, it would
seem a very simple process of deduction to discover that cow-pox
inoculation was the solution of the problem of preventing the
disease. But there was another form of disease which, while
closely resembling cow-pox and quite generally confounded with
it, did not produce immunity. The confusion of these two forms of
the disease had constantly misled investigations as to the
possibility of either of them immunizing against smallpox, and
the confusion of these two diseases for a time led Jenner to
question the possibility of doing so. After careful
investigations, however, he reached the conclusion that there was
a difference in the effects of the two diseases, only one of
which produced immunity from small-pox.
"There is a disease to which the horse, from his state of
domestication, is frequently subject," wrote Jenner, in his
famous paper on vaccination. "The farriers call it the grease.
It is an inflammation and swelling in the heel, accompanied at
its commencement with small cracks or fissures, from which issues
a limpid fluid possessing properties of a very peculiar kind.
This fluid seems capable of generating a disease in the human
body (after it has undergone the modification I shall presently
speak of) which bears so strong a resemblance to small-pox that I
think it highly probable it may be the source of that disease.
"In this dairy country a great number of cows are kept, and the
office of milking is performed indiscriminately by men and maid
servants. One of the former having been appointed to apply
dressings to the heels of a horse affected with the malady I have
mentioned, and not paying due attention to cleanliness,
incautiously bears his part in milking the cows with some
particles of the infectious matter adhering to his fingers. When
this is the case it frequently happens that a disease is
communicated to the cows, and from the cows to the dairy-maids,
which spreads through the farm until most of the cattle and
domestics feel its unpleasant consequences. This disease has
obtained the name of Cow-Pox. It appears on the nipples of the
cows in the form of irregular pustules. At their first appearance
they are commonly of a palish blue, or rather of a color somewhat
approaching to livid, and are surrounded by an inflammation.
These pustules, unless a timely remedy be applied, frequently
degenerate into phagedenic ulcers, which prove extremely
troublesome. The animals become indisposed, and the secretion of
milk is much lessened. Inflamed spots now begin to appear on
different parts of the hands of the domestics employed in
milking, and sometimes on the wrists, which run on to
suppuration, first assuming the appearance of the small
vesications produced by a burn. Most commonly they appear about
the joints of the fingers and at their extremities; but whatever
parts are affected, if the situation will admit the superficial
suppurations put on a circular form with their edges more
elevated than their centre and of a color distinctly approaching
to blue. Absorption takes place, and tumors appear in each
axilla. The system becomes affected, the pulse is quickened;
shiverings, succeeded by heat, general lassitude, and pains about
the loins and limbs, with vomiting, come on. The head is
painful, and the patient is now and then even affected with
delirium. These symptoms, varying in their degrees of violence,
generally continue from one day to three or four, leaving
ulcerated sores about the hands which, from the sensibility of
the parts, are very troublesome and commonly heal slowly,
frequently becoming phagedenic, like those from which they
sprang. During the progress of the disease the lips, nostrils,
eyelids, and other parts of the body are sometimes affected with
sores; but these evidently arise from their being heedlessly
rubbed or scratched by the patient's infected fingers. No
eruptions on the skin have followed the decline of the feverish
symptoms in any instance that has come under my inspection, one
only excepted, and in this case a very few appeared on the arms:
they were very minute, of a vivid red color, and soon died away
without advancing to maturation, so that I cannot determine
whether they had any connection with the preceding symptoms.
"Thus the disease makes its progress from the horse (as I
conceive) to the nipple of the cow, and from the cow to the human
subject.
"Morbid matter of various kinds, when absorbed into the system,
may produce effects in some degree similar; but what renders the
cow-pox virus so extremely singular is that the person that has
been thus affected is forever after secure from the infection of
small-pox, neither exposure to the variolous effluvia nor the
insertion of the matter into the skin producing this
distemper."[2]
In 1796 Jenner made his first inoculation with cowpox matter, and
two months later the same subject was inoculated with small-pox
matter. But, as Jenner had predicted, no attack of small-pox
followed. Although fully convinced by this experiment that the
case was conclusively proven, he continued his investigations,
waiting two years before publishing his discovery. Then,
fortified by indisputable proofs, he gave it to the world. The
immediate effects of his announcement have probably never been
equalled in the history of scientific discovery, unless, perhaps,
in the single instance of the discovery of anaesthesia. In Geneva
and Holland clergymen advocated the practice of vaccination from
their pulpits; in some of the Latin countries religious
processions were formed for receiving vaccination; Jenner's
birthday was celebrated as a feast in Germany; and the first
child vaccinated in Russia was named "Vaccinov" and educated at
public expense. In six years the discovery had penetrated to the
most remote corners of civilization; it had even reached some
savage nations. And in a few years small-pox had fallen from the
position of the most dreaded of all diseases to that of being
practically the only disease for which a sure and easy preventive
was known.
Honors were showered upon Jenner from the Old and the New World,
and even Napoleon, the bitter hater of the English, was among the
others who honored his name. On one occasion Jenner applied to
the Emperor for the release of certain Englishmen detained in
France. The petition was about to be rejected when the name of
the petitioner was mentioned. "Ah," said Napoleon, "we can refuse
nothing to that name!"
It is difficult for us of to-day clearly to conceive the
greatness of Jenner's triumph, for we can only vaguely realize
what a ruthless and ever-present scourge smallpox had been to all
previous generations of men since history began. Despite all
efforts to check it by medication and by direct inoculation, it
swept now and then over the earth as an all-devastating
pestilence, and year by year it claimed one-tenth of all the
beings in Christendom by death as its average quota of victims.
"From small-pox and love but few remain free," ran the old saw. A
pitted face was almost as much a matter of course a hundred years
ago as a smooth one is to-day.
Little wonder, then, that the world gave eager acceptance to
Jenner's discovery. No urging was needed to induce the majority
to give it trial; passengers on a burning ship do not hold aloof
from the life-boats. Rich and poor, high and low, sought succor
in vaccination and blessed the name of their deliverer. Of all
the great names that were before the world in the closing days of
the century, there was perhaps no other one at once so widely
known and so uniformly reverenced as that of the great English
physician Edward Jenner. Surely there was no other one that
should be recalled with greater gratitude by posterity.