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INTRODUCTORY
TO   THE   COURSE  OF   LECTURES
THEORY AND PRACTICE OF PHYSIC,
IN  JEFFERSON   MEDICAL   COLLEGE,
/
SESSION MDCCCXXXII—IIP,
                     BY JOHN REVERE, M. D.

Professor of the Theory and Practice of Physic in Jefterson Medical College; Member of the
     Royal Physical Society of Edinburgh, of the Lyceum of Natural History of
         New York, and of the New York Literary and PJtihjSTOhicaLSpciety.


                                         Kit''?-
%?A.V
            P HILADELPHIA:

FRENCH & PERKINS—159 CHESTNUT STREET.

                     1832.
* 
WM. F. GEDDES, PR. 9  LIBRARY  ST. 
To   Granville Sharp Pattison,  M.  D.  Professor of  General, Descriptive
  and  Surgical Anatomy, and John Jievere, M. D. Professor of the  Theory
  and Practice of Physic, of Jefferson Medical College.
Gentlemen,
     We, the undersigned,  are  appointed a  committee  by the students
composing your  classes, to solicit of you copies of your Introductory Lec-
tures, for publication.  In complying with this request, we feel assured that
you will not only confer a lasting honor on the Institution in which we are
acquiring our medical education, but it may be the means of communicating
to society generally, and particularly to the medical world, the great advan-
tages we enjoy.
     We are,  gentlemen,  with great respect,
                          Your obedient servants,
                 (Signed)                       M. M. LEVIS,
                                                GEO. W. ALLEN,
                                                J. MITCHELL,
                                                G. A. WILLIAMS,
                                                HUSON  SWAYNE.
     Jefferson Medical College,
Philadelphia, November 10, 1832.
                                        Philadelphia, November, 1832.
Gentlemen,
    My friends, and those of Jefferson Medical College, in whose judgment
I place implicit confidence, have advised the publication of the discourse
delivered by me introductory to my present course of lectures on the Theory
and Practice of Physic.  In compliance with your wishes and  their advice,
rather than from my own conviction,  I have consented to this, though most
remote from my intentions when it was written.
    Will you have the  goodness, gentlemen, to communicate to your fellow
students how much I feel gratified and flattered by this mark  of their kind
wishes and favorable opinions.
    With sentiments of personal respect, and unaffected interest in your
welfare,
                 I remain, gentlemen,
                                Your obedient servant,
                 (Signed)                            J. REVERE.
Messrs. M. M. Levis,
        Geo.  W. Allen,
        J. Mitchell,
        G. A. Williams,
        HCSON  SWATNE. 
 
A  DISCOURSE,  &c.
  It would be affectation in me, gentlemen, not to acknow-
ledge, that I appear before you on the present occasion with
feelings of solicitude  and strong  excitement.  To attempt to
build up a new school of medicine under the shadow of an
institution which has thrust its roots so deeply, and spread its
branches so widely abroad in society; an institution founded
by some of the ablest men our country has produced, and which
has for so many years assumed a sort  of hierarchal authority
in matters pertaining to medical science, until  her decrees
have come to be considered almost infallible, and to question
them almost sacrilegious; I  say, such an attempt will  be ad-
mitted by all to be an enterprise of no ordinary magnitude. In
other countries, where the circumstances of time and existing
authority control  every  other;  where  even abuses become
consecrated by age, and where the excellence of public institu-
tions is  rather measured by  the length of their duration than
their intrinsic usefulness, our enterprise would be considered
 chimerical and desperate.  But in this  country, where inherent
 excellence constitutes the only acknowledged claim upon pub-
 lic patronage; where it is universally understood that public
 institutions are founded for the promotion of the public  good,
 not merely individual advantage, we  feel  conscious that our
 school must stand or fall by  its own merits.  We are conscious
 that it is neither the sneers of our rivals that can obstruct, nor
 the triumphal shouts of  our friends that will bear us forward 
6
to success, but that for this, both they and we must look to one
great result—the comparative facilities that can be offered for
acquiring a sound medical education.   This, therefore, consti-
tutes but a subordinate source of my anxieties.
  But there is another consideration which presses upon my
mind, and which applies personally to myself.  It is the relation
in which I stand to my colleagues.  With them, success  as
public teachers of  medicine is a problem no longer to  be
solved.   They have already passed  the  ordeal, and some  of
them  with a brilliancy that falls to the lot of very few.  For
myself, placed in  a chair not inferior, to  say the least, to any
other in its  importance in a medical education; one  that  in-
volves all the learning of the profession, and is, as  it were, a
sort of summing up of all the other branches, I cannot but feel
how difficult it will be to sustain this high standard, so  as to  do
justice to you and to satisfy myself. With little that is amusing
in its  details;—resting alone on observation and reason; and
incapable of illustration by brilliant experiments or striking de-
monstrations to break in upon the tedium of dry investigation;—
the claims of the  chair of the Theory and Practice of Physic
upon  your attention, must altogether rest upon its intrinsic im-
portance.  Under these disadvantages, I  must depend on your
candor and  my own unaffected devotion  to the duties of my
situation for my hopes of success.
  In  order that we may  enter upon  this important, though,
perhaps, unattractive branch of medical science, with any rea-
sonable hopes of  success, it will be indispensable to establish
some clear and well-defined principles  and rules by which our
inquiries shall be governed.  I have thought, therefore, that I
could not better employ the present occasion than by an exami-
nation of some of the more prominent  rules and principles
which will guide my inquiries. 
1
  Science is knowledge;  and its only legitimate  object is  the
acquisition of truth.   The  first  great moving principle that
every sincere disciple of science  should cultivate, is an ardent,
uncompromising love of truth. This must be the end, therefore,
of all his exertions;  the polar star by which he directs all  his
inquiries; and he must follow with a cautious, but  unhesitat-
ing step, wherever it points the way, perfectly sure that its end
must be good.   For the investigations of science, a sound and
discriminating judgment is the faculty most requisite, and must,
therefore, be duly fostered.
   The mind, naturally impatient of delay,  submits with  re-
luctance  to  the slow and  toilsome methods  of  acquiring
truth to which it is  destined, and is inclined to overleap every
obstacle, and grasp  the treasures of  science by a single effort.
It is rare, however, that  such attempts are  successful.  This
has  been strongly exemplified in medicine, in  the innume-
rable hypotheses with which its history abounds.   There is no
point on which  the  medical student  should be more guarded
than this.  To one just entering the threshold of science, there
is something particularly attractive in hypothesis; it seems to
imply  genius and invention, those higher attributes of mind
which always command our admiration and respect.  But this
is a mistaken opinion;  a taste for hypothesis in science rather
indicates a frivolous than a vigorous intellect. Yet it certainly
forms  a predominant  feature in  the history of our profession;
through its whole progress they may be traced rising and fall-
ing, like  the waves of the ocean, in  endless  succession.  Un-
doubtedly there have  been some which, like frost-work upon
the casement, have presented forms so symmetrical and beauti-
ful, that they could scarcely be contemplated without admira-
tion ; yet, like it, they have vanished with the first breath of
reason, nor left  a trace behind. 
8
   But look at those names which, in the history of the profes-
 sion, have shone and still shine with undiminished lustre, and
 which indicate to the student the true road to professional dis-
 tinction.  Inquire how they have acquired this deathless re-
 nown, and come to be accounted among  the  benefactors of
 mankind.—Did Hippocrates, and Harvey, and Sydenham, and
 Jenner, and Laennec, and a host of others, arrive at their most
 enviable distinction by their speculative opinions 1—Did they
 waste their  high intellectual energies  on these, the  mere
 baubles of science ?   No!
   The object of science is not amusement, but instruction. It is
 to constitute our  guide in the all-important search after truth.
 In literature, the imagination may be permitted to indulge itself
 free from restraint.  The fancy of the poet may wander from
 earth to heaven, and  appropriate to its fantastic humor  all it
finds in each.  But it is  necessary to exclude this whimsical
 and capricious power from the sober precincts of science.
  The sciences are divided into two great classes;—the mathe-
matical and physical, which differ essentially from each other in
their nature and history.  The mathematical sciences are con-
cerned in investigating the  relations of number and extension,
qualities that may with certainty be discovered.   The nature of
mathematical reasoning is such, that if the premises be true and
the series accurately conducted, the result must be truth.  When
Pythagorus announced to the world the relations of the squares
of the sides of a right-angled triangle, it  must  have been per-
ceived that it was true.  It was at once discovered that all the
facts then known, or that might afterwards be found out,  could
have no effect in either increasing or diminishing its certainty.
In the emphatic language of Dr. Johnson, it must have been im-
mediately perceived, "that it was one of those truths that had
nothing to hope  or  to fear from the lapse of time, or the 
9
        progress of human improvement." Euclid's Elements of Geome-
        try affords another striking illustration of the universality and
V      invariableness of the mathematical sciences.  It is more than
        two thousand years since this book was written.  It is said to
        have been translated into the language of every nation, ancient
        or modern, where civilization had advanced far enough for the
        comprehension of abstract truth.  Since then, the most power-
        ful empires have risen to maturity, and sunk into decay; and,
        at one time, almost all the records of huma n learning were lost
        in profound darkness and universal barbarism.  Yet this book
        has survived every vicissitude, and  its truths are as much ad-
        mired and as  universally acknowledged at the  present  day
        as in that of their author.
          On  the  other  hand, the  physical  or  natural sciences,
        which include medicine  and natural  history,  in all  their
        various  branches, are nothing more than the accumulated
        observations  of  mankind  on the laws and  phenomena of
        nature, and  an attempt  to classify and  deduce from them
        certain general principles.   They depend for the most part
        on the evidence  of our senses,  and our  intellectual percep-
        tions. These are liable to numerous illusions, and necessarily
        vary essentially in different individuals.  Their origin is often
        the mere result of  accident.  Our investigation of  them com-
        mences  in conjecture, at  first vague  and incoherent; and it is
        only by  a long series of  careful and well-directed  efforts that
        we can at last hope to approximate the truth.   After all, it is a
        mere  approximation; for it is rare, indeed, that  we  arrive at
        that degree of certainty in the physical sciences which charac-
        terizes mathematical truth.  This striking difference between
        the exact and physical sciences, affords a satisfactory solution
        of the difference of their progress.  The mathematical sciences
        acquired a high degree of perfection at a very early period in
        the  history of human  civilization;  while the physical,  until
                                    2 
                           10
within the last two hundred years, had scarcely attained that
degree of exactitude which could entitle them to  the rank of
sciences.  Within that time,  however, they  have advanced
with a rapidity that, were it  not a matter of history, would
appear scarcely credible.   Take any of the physical sciences,
and compare their present state with their condition two hun-
dred years since, and  you cannot but be astonished at the im-
provements they have undergone.   Take, for example, though
it is by no means the most striking one, the state of knowledge
at that  period respecting the  structure  and functions of the
human body.  The functions of the stomach  and the process
of digestion were but obscurely conjectured ; the structure and
functions of the nervous system,  as at present understood and
demonstrated, were entirely unknown; the lymphatics had not
been discovered; even the anatomy and offices of the circu-
lating organs were as a sealed book.  I have preferred to illus-
trate the state  of the physical  sciences at that period, by this
example taken from our profession, because it is  more german
to the objects of this Institution.   But the observation applies
with tenfold force to  the  other branches of  natural scienca
—Chemistry consisted of a mere unintelligible jargon, and was
entirely in the hands of mountebanks and other public impos-
tors ;  while botany, mineralogy, and geology could not be said
to exist as sciences.
  The question naturally arises,  to wrhat remarkable circum-
stance in the history of the human understanding must we im-
pute the extraordinary advances that have been made in that
short period in the natural sciences?—How has it happened, in
the space of less than two hundred years, that this most impor-
tant department of human knowledge;  one so intimately con-
nected with the necessities and convenience of man,  has  made
infinitely greater progress than in the  thousands of years that
preceded?—Is this a cause or an effect of modern civilization?— 
11
Has the species undergone improvement in its organization?—or
have the moderns devoted themselves with more enthusiasm to
the cause  of learning than the ancients?—All our knowledge
and experience give a prompt negation to all these suppositions.
This remarkable moral phenomenon is manifestly imputable to
a cause much more superficial and obvious; to an influence as
simple as it  is energetic.   It  is merely the different modes pur-
sued by the  ancients and moderns in i?ivestigati?ig these departments
of knowledge.   I know of nothing more important in the educa-
tion of a medical student, whose life is to be  devoted to  the
pursuit  of the physical sciences, than  a full and clear appre-
hension of this all controlling  circumstance.  True wisdom is
chiefly acquired by a right understanding of the experience and
errors of others.   If then we would wish to guard ourselves
and our  profession  from  the  insurmountable  obstacles to
improvement, which for so many ages completely obstructed
its  progress, we  must carefully  study  and  understand  the
causes of these different results.
  There are two different systems which have been pursued in
investigating the physical  sciences; they  may be called  the
Synthetic and the Inductive Methods.
  The synthetic method, which was generally pursued by the
ancients, consists in assuming certain general  principles to be
true;  in other words to form an hypothesis, by which we may
attempt to  explain  all the  known  facts and principles of any
science.   Thus  the  hypothesis  of the ancient  chemists as-
sumed that there were but  four elementary bodies: earth,  air,
fire, and water.   All  the changes  in nature were ascribed to
the different modifications which these elements undergo; and
the most preposterous problems were  gravely proposed for
solution,  as corrollaries, from these false  premises.   Hence
ages were  spent by the alchemists in pursuit of those dreamy
chimeras, which men in all  ages have been so prone to account
among the primary elements  of  human happiness, perennial 
12
 youth and inexhaustible wealth, under the name of the phi-
 losopher's stone.
   The history of medicine, until very recently, consists of little
 else than a description of the different hypotheses which have
 flourished in different ages.  They also afford striking illustra-
 tions of  the insufficiency of the synthetic method  in the inves-
 tigation of the natural sciences.   Though medicine is known to
 have existed as a separate profession for more than one thou-
 sand years before  the birth of Hippocrates, yet he has always
 been regarded as its founder, because he was the first who im-
 parted to it that degree of precision of knowledge which could
 at all entitle it to the rank of a science.  He was the first who
 attempted to form a pathological hypothesis, founded on anato-
 my and physiology, as they were then understood.  That this
 first  attempt must  have  been  very imperfect, necessarily
 followed from the entire ignorance at that period of anatomy,
 the  foundation of  medical  science.   It  is  quite  manifest
 from his works, that this first medical philosopher knew no dif-
 ference between the arteries, veins, nerves, and tendons, as he
 uses the  same word to signify each.
  On  such loose analogies was the  first medical hypothesis
 formed.  But imperfect and inconclusive as it was,  it formed
 the basis of all the innumerable medical hypotheses that have
 been  in fashion from that period to the commencement of the
 present century.   The humoral pathology, which was  but a
 fragment of the Hippocratic hypothesis, may also be mention-
 ed as an example of the inadequacy of the  synthetic method
 for investigating the physical sciences.   Under different modi-
 fications, it maintained  its ground for ages, and was received
 with  the highest admiration and implicit confidence as un-
 doubted truth.
  Assuming that their hypotheses must be true, physicians drew
 the most absurd corrollaries from them in their practice, affect-
ing to have reduced the practice of medicine to mathematical 
13
 precision and certainty.   The following  directions, given for
 fixing the dose of a certain medicine, taken from a prescription
 of one of  these humoral pathologists, will enable you to form
 some idea of the absurd extremity to which these doctrines
 were carried.   " You are to dose so much of the medicine as
 is spent upon the stomach and intestines directly as the consti-
 tution; and  so much as is carried into the blood as the square
 of the constitution; and this sum into the person's size, is the
 quantity required."   Absurdity  can go no further!  This
 result of the  hypothetical  or  synthetical method  of inves-
 tigating  medical  science,  forms  the best  commentary on
 its entire  insufficiency to this purpose, and  I shall therefore
 press the  matter no further.  If, then, the object of science
 be the acquisition of truth, it will be  admitted, that the synthe-
 tic method, which was the only one adopted by physicians for
 several  thousand years, has been proved by experience to be
 entirely unsuitable for this purpose.
   After so many ages had been passed in a fruitless attempt to
 improve this department of  human knowledge, it  was at  last
 suspected that there must be something radically wrong in the
 mode of pursuing it.   It was not until the commencement of
 the 17th century, that the true nature of the difficulty was dis-
 covered and the proper remedy administered.
   Bacon was the first who perceived and exposed the absur-
 dity and futility of this mode of philosophizing, and  proposed to
 substitute in its place the inductive, or as it has been called af-
 ter its founder, the Baconian method.  In  a work  entitled the
 Novum Organum he pointed  out  the  necessity of  abandoning
 the synthetic method  and following  an opposite course.  The
 broad basis assumed by the inductive philosophy is to take no-
 thing for granted; to admit no proposition in science to be true
 until it has been proved by experiment; to suspend our reason-
ings about  causes and  to verify effects; to abandon mere sup-
positions respecting the operations of nature, and set ourselves 
14
patiently to observe  what  those operations are.   Accord-
ing to the principles of the inductive philosophy, nothing is to
be gained in science,  by assuming as true any point which is
doubtful or not susceptible of proof.  Science means knowledge,
not conjecture or opinion;  to entitle any department of human
inquiry  to the rank of a science, it is necessary to collect toge-
ther clearly established facts,  and by fair and legitimate rea-
sonings, to deduce those useful truths  that naturally flow from
them.   So long as we pursue this  course in our reasonings,
they are strictly scientific; but the moment we deviate from
this line, though we may be entitled  to the commendation of
being ingenious, or imaginative, or clever, we are no longer
scientific.   These principles cannot be too frequently or too aus-
terely inculcated, especially in an inquiry like medicine, every
deduction of which affects  so deeply the welfare of society.
The end of science is to give precision to our knowledge; to de-
fine what we know, so that it may be distinguished from what
is merely conjectured.   By drawing the line manfully between
them, and frankly acknowleging our ignorance, we leave open
for future investigation those points that are doubtful.
  The soundness of these views were at last perceived and  ad-
mitted.  The introduction of the Baconian, or inductive philo-
sophy, constitutes a new, and by far the most important era, in
the physical sciences.   Though its adoption was slow, yet its
influence, on their advancement, has exceeded all that could
have been anticipated, even by its most sanguine admirers.  Its
truth  is now universally admitted, and all who are engaged in
improving the physical  sciences, or instructing others are, or
at least affect to be, governed by its laws.
  We have only time to make a hasty comparison of the differ-
ent results of the synthetic  and inductive  methods, in a  few
striking examples.   Perhaps a more favourable example of the
synthetic  method of reasoning in physical science cannot be
found than the Natural  History of Pliny.   It was written  in a 
15
country and at a period when the exact sciences were cultivat-
ed with success; when the standard of literary taste had at-
tained its highest  elevation;  and when all  those arts which
minister to the luxuries and elegancies of life, had arisen to a
degree of perfection, which has, perhaps, never been equalled in
the history of our species.  Its author, Pliny the elder, as he is
usually called, was not only a statesman and a soldier, but one
of the most indefatigable  and enthusiastic scholars and learned
men that ever lived.  Every moment that could be  spared
from more urgent  and  active  duties,  was  devoted to lite-
rary and scientific pursuits, and his life at last sacrificed to these
pursuits.  He perished during an eruption of Mount Vesuvius,
while  observing that phenomenon, about the commencement
of  the  Christian era.  His Natural History is the only one of
his works that has been  transmitted to us.   It bears abundant
evidence of the genius  and industry of its author,  and is the
most valuable relict  of ancient natural science we possess.  It
comprises all that was known at that time on the various sub-
jects on which it treats.—Compare, then, the Natural History of
Pliny with the works of  our most eminent modern natural his-
torians and chemists; for  example, Cuvier, Sir Humphrey Davy,
or Mr. Dalton.   You will find the former containing a few doubt-
ful facts and  principles, mingled  with  dreamy speculations,
amusing  fables, and idle conjectures.    In the latter you will
find no facts or principles, admitted as such, that are not well
defined and clearly established.   The speculations and deduc-
tions founded on such bases as these, though grand and impos-
ing, and sustained by the strongest analogies, you will find pro-
posed with modesty, as proper subjects for inquiry, not advanc-
ed as theories, the truth  of  which is ascertained, and which no
one is at liberty to question.   When Mr. Dalton published his
views of the atomic theory, he must have been  conscious that
the thought was surpassingly brilliant, and that it was sustain-
ed by all  the known  analogies of the science of chemistry. But 
16
 animated with the true spirit of the inductive philosophy, he
 modestly proposed it as a fit subject of inquiry, leaving to time
 and accumulated observation to test its truth and elaborate its
 consequences.   Sir Humphrey Davy informs us, in one of his
 last communications,  that the  decomposition of the alkalies
 and his  discoveries of the  electro-chemical relations of the
 metals  were founded  on a  generalization, conceived by him
 quite early in his career, viz. that chemical and electrical at-
 traction are identical.   This  brilliant idea, the foundation of so
 many admirable discoveries, and which appears to lay open a
 mystery of  nature almost as profound as that of life, was not
 decidedly announced  until near  the period of his death, and
 then, only suggested as a speculation worthy of being further
 investigated.   The inference I draw, from this comparison of
 the most eminent of the ancient with those of the modern na-
 tural philosophers, is, that the striking superiority of  the latter
 is not attributable to individual excellence, but ta their having
 enjoyed  the  happiness  of   living  in an age when  sounder
 principles of philosophizing prevailed.
   To form a somewhat more definite idea of the potency of the
 inductive philosophy, I may be permitted to allude to a few of
 its more remarkable  achievements.  Some  of them  will be
 found such, as  apparently to surpass human ability.  It has
 enabled man to vanquish two  obstacles, apparently insurmount-
 able  to a being of his  finite powers—time  and space.  It has
 enabled him to  solve mysteries, the very enunciation  of which
 seems to involve  impossibility  and absurdity.  When it was
 first  proposed to inquire respecting the changes  which had
 taken place in the crust of this globe, thousands of ages before
 the creation of man, it was ridiculed as  the most monstrous of
human absurdities. The geologist was  compared  to a fly
lighting on the side of an elephant, and, after thrusting his pro-
boscis into his  skin, undertaking to speculate on his internal
constitution and structure.   Again, how preposterous does  it 
                             17
 appear,  at first sight,  to inquire whether this earth was origi-
 nally a distinct body moving in space, or a mere fragment of
 another planet.—Yet  the investigations  of modern natural
 philosophers, among whom  the name of  Cuvier  stands pre-
 eminent, sustained by the spirit of the inductive  philosophy,
 have already gone far towards the elucidation of  these most
 extraordinary problems.
   It is a remarkable fact, that though there is no class of men
 who have been so much devoted to science in modern times as
 the  members of our  profession, yet in none of the physical
 sciences has the inductive philosophy been admitted with more
 reluctance than  in medicine.  Apollo was formerly the God
 of physicians as  well as poets;—and it will be  admitted that
 none of  his worshippers offered more abundant gifts upon his
 altars, or performed their prostrations with  more  zeal and
 devotion.—But the  spirit of the inductive philosophy  has at
 length arisen, and, with an  unsparing hand and homely good
 sense, brought about a medical reformation. The consequence
 has been, that  the altars  of the false God  have been thrown
 down, and his image trampled in the dust, and the temple of
 nature and the spirit of truth substituted in their place.   From
 this  altar, every offering of the imagination  is rejected: its
 motto is, " Observation and experiment."
   The maxims of the  inductive philosophy have been  more
 and  more strictly  adhered to  in  anatomy, physiology, and
 several departments of surgery.  The brilliant discoveries of
 the circulation of the blood; of the structure and functions  of
 the lymphatics; the  magnificent investigations of Mr. C. Bell
 on the anatomy  and offices  of the nervous system; and the
 astonishing results of modern operative surgery, are among
 the glorious fruits of this mode of philosophizing.  In medicine,
from various causes,  the progress has been  slower.   The
greatest  obscurity necessarily pervades  all living  processes,
                            3 
18
whether healthy or morbid.  But in those  internal maladies
where  there are none, or but slight and doubtful changes of
structure, and where, in most cases,  death does not occur, the
difficulty of arriving at correct opinions is vastly increased.
But though it  must be admitted that the difficulty  of attaining
that degree of precision in our knowledge which may be said
to constitute science, is  particularly great  as applied to the
principles and practice of Physic, still it is equally apparent
that these difficulties can only be overcome  by a strict adher-
ence to the maxims of the inductive philosophy.   The obsta-
cles which have been vanquished in the other physical sciences,
are sufficient to show, that perseverance must at last be crowned
with success also in this.
   As preparatory to a consummation so ardently to be wished,
the first step has been taken, though tacitly,  by the profession.
It is  the  abandonment of the taste for  system-making  and
voluminous writing, which, for so long a time, engrossed the
master spirits of the profession.   Since the time of Cullen, the
last of the systematic writers of any name,  the gifted  men of
the profession have  devoted  themselves  to elaborating those
various departments of medicine that inclination and the force
of circumstances have  thrown in their way.  When we look
 for the works and  names of those who have  produced the
 greatest influence in the profession for the last half century, we
 find them in the form of detached memoirs in the  transactions
 of learned societies; in periodical  publications, and separate
 treatises.  Every new and important fact,  mingled, no doubt,
 with many that possess neither of  these qualities, and many
 doubtful  old ones, have  thus been brought, as it were, under
 the purview  of the profession, and strictly scrutinized and
 compared  with the observation and  experience of others.
 The periodical journals, which constitute so important a part
 of modern medical literature, have been found most effective 
10
machines for separating the wheat from the chaff, the diamonds
from the mud and exuviae with which they were mingled.
  By pursuing  this system, already have we arrived at some
noble results in the cause of humanity  and science.  I shall
here advert to but two  examples of  this kind;  the admirable
discovery of Jenner, and the invention of the stethescope, and
its  application  to investigating  the diseases of the chest by
Laennec.  They are both the results  of  pure induction.  The
former  is  the  greatest  achievement  in  the whole circle of
the sciences in  diminishing human suffering and waste of life.
The latter, one of the most admirable examples of exact obser-
vation and philosophical  induction with which lam acquainted.
  With such a  noble basis for the improvement of our know-
ledge of the principles and practice of physic, is it not a matter
of regret,  that an individual should be found endeavoring to
mar and set aside a  system of  investigation from which such
first fruits have  already been  obtained, and to restore the
synthetic method, so long the opprobrium of our profession ?—Is
it not a matter of surprise, that in this country individuals should
be found, occupying the high places in the profession, willing to
become the disciples of such a master, the propagators of such
doctrines ?
  I have thus  endeavored to lay before you a rapid  sketch
of the true nature and  only legitimate objects of the sciences
—the acquisition of truth; of the causes  which,  for  so  many
ages, obstructed  the physical  sciences,  so that they  could
scarcely be said to have advanced at all; and, lastly, of the
nature of those  influences by which they have made such rapid
progress towards perfection during the last two hundred years.
It has constituted a principal object in doing  this to furnish your
minds with a just standard by which you may test the remarka-
able system called Brousaissism, or the " physiological system,"
of which so much of late  has been heard.  I am induced
to direct your  attention  to  this innovation in medicine, not 
20
 from its intrinsic  importance—for in Europe its influence is
 chiefly confined to Paris, and even there,  for the most part, to
 the purlieus of Val de Grace.  But in this country, it has been
 attempted, by the authority of public teaching, and the influence
 of the medical press, to disseminate and enforce these doc-
 trines.  You are well aware that it would be quite out of the
 question, in the little time that remains  to me, to pretend fully
 to expose its dogmatism and innumerable  fallacies, which I
 cannot but' regard as  most pernicious  and disgraceful to  the
 medical literature of  our  country.  I must  content myself
with pointing out a few of its more glaring  defects.
  The first grave charge against the writings of M. Broussais,
 is the total  abandonment of all the great principles  of the in-
 ductive philosophy.   Instead of following the universally  ac-
 knowledged maxim in all the physical  sciences, of  admitting
 nothing to be true until it is proved, the works of Broussais are
 filled with assumptions so gross, that they absolutely confound
 us by their audacity.   These gross assumptions are so mixed
 up with principles notoriously true, and universally  admitted,
 that none but a well read physician can discriminate between
 them.   You constantly meet, in the same paragraph, general-
 izations at which the united observation of the profession had
 long since arrived, and the wildest speculations of this presum-
 ing theorist, stated precisely in the same tone, as if equally  en-
 titled to confidence and equally the results of his own original
 observation. The doctrines of Broussais being essentially dif-
 ferent from those  of Cullen or Brown, the last writers of any
 reputation who have pretended to found new systems in medi-
 cine, persons of limited acquirements have therefore inferred,
 that what they find in Broussais  different from these  authors
 is originally and peculiarly his.   I cannot but suspect that this
 is the foundation of the popularity of the doctrines of  Broussais
 in this  country.   The ground of this opinion is, that, both in
 Europe and the  United States, with very few exceptions,  his 
21
 followers are confined to the younger, and by no means the
 best informed members of the profession.   On the other hand,
 with scarcely an exception, as far as my personal knowledge
 goes, all those physicians who are distinguished for the sound-
 ness of their education, the profundity of  their acquirements,
 and the vigor of their minds, unanimously agree that there is
 scarcely  a doctrine advanced by him, that has the least claim
 originality; while the few that appear to possess this claim
 are false in principle and fact, and tend to the most dangerous
 errors in practice, especially in  this  country.
   But you would  suppose  that the characteristic  doctrines
 of M. Broussais, right  or  wrong, were  at  least sufficiently
 well known,  and strongly marked.    This,  however, is far
 from being the case; the whole affair is clouded in mystery.
 Like the veiled prophet in Lalla Rookh, whose august presence
 could  not be endured, and  whose  dazzling countenance,  it
 was profanation to look upon, the features of the  "Physiologi-
 cal Doctrine" are unknown even to its disciples and worship-
 pers.   I have anxiously perused the published works of Brous-
 sais, and several  of those of his disciples, in  the  hope of be-
 coming acquainted with what was claimed as original—but
 without success.   I have inquired of  some of the most intelli-
 gent Broussaisists—what do you consider the peculiar and dis-
 tinctive characters of these doctrines?—I have never met an in-
 dividual who gave a direct and intelligible  reply.  I have
 narrowed the question, and inquired—has  M. Broussais disco-
 vered any new fact or principle in physiology or pathology, or
 thrown new light upon old ones?—They cannot point them out.
 I have said,—do you consider his 'doctrine, that inflammation of
 the mucous membrane of the  stomach is the primum mobile and
 ultimum moriens of disease, as constituting his principal claim to
distinction, and that he has clearly established its  truth by in-
duction?—or was it Broussais who originally suggested that in-
flammation of the stomach is the proximate cause of  fever?— 
22
Even his most enthusiastic admirers will not pretend to answer
in the  affirmative, if their minds  are in the slightest degree
imbued with the learning of their profession.
  Nor  is this obscurity confined to the great doctrines of M.
Broussais, but it appears to me to pervade all his works, and
almost every part of them.   In the course of our lectures we
shall have occasion to examine more at large some of the doc-
trines advanced by M. Broussais.  It is necessary, however, to
give a specimen  of the defects in his works, to which I have
alluded.  They may be  found in every part of them.  I have
taken but little trouble  in selecting the following, and chiefly
for its brevity.  It is taken from his 15th Phys. Prop.  "Every
stimulation,"  says  he, "capable of producing a perception
in the  brain, passes  through the  whole  assemblage of the
nervous system of relation.  It goes then to be repeated in the
mucous membrane, from whence it is again sent back to the
centre  of perception, which judges of it according to the opin-
ion of  the viscus to  which the mucous membrane belongs, and
which  disposes itself to act according to the pleasure or pain it
receives; and the object of this action is always to cause the
duration and repetition of the  impression, or the removal of the
cause of it."—This is  a fair sample of M. Broussais' physiolo-
gical opinions and modes of reasoning.  It sounds very learned
-but will any man' of  sense pretend that  he understands it?—
and as far as it is intelligible, can any thing more preposterous
be  found in  the wildest vagaries of  the humoral pathology,
than this consultation  between the  brain  and  the mucous
membrane?—Even  the  mathematical  prescription I  have
before quoted is not  more senseless  or  ridiculous.
   It may be laid down as a  rule,  gentlemen, to which  there
are very few exceptions, that the soundness of men's views on
scientific subjects may be tested by the clearness with which
they are expressed.  It has been remarked as the highest test of
literary excellence, that the truths which it imparts to our mind 
23
are so clear and graphic that they seem to be the mere shadow-
ing forth of  our own thoughts.  If a man  has clear and dis-
tinct images in his own mind, he rarely fails in communicating
them to others.  If they will not bear this test;  if they are con-
fused and mystified;  and, especially, if they affect extreme
nicety, making  distinctions where others can perceive no dif-
ferences ; and if, to all these suspicious circumstances, be added
a pretension to something  new and original, you will be seldom
mistaken if you conclude either that the individual is misled by
his own  confused and muddy thoughts, or that he is a charla-
tan and means to mislead  others.  The adage is as true as it is
current,  " if the well be clear you may see the bottom."  So
it is with men's thoughts;  if they  are  turbid and incompre-
hensible, it is owing to a want of transparency in the medium
in which they exist.
   I have one more observation  to  make  on Broussaisism.__
We might pass over the dogmatism of his manner;—we might
smile at the  formal obscurity in which  himself and followers
so much delight, and which  they appear to have mistaken as
an evidence of science;—we might have  submitted in silence
to his violation of all the  maxims of the inductive philosophy;
but I should have omitted an important duty did I not point
out to you  the  dangerous practical tendencies  of these doc-
trines.   In  the temperate  and  long  cultivated  regions  of
France, diseases are slow in their progress, and demand the
use of less powerful remedies.—But in this country, especially
the southern parts of  it, where the  diseases,  like those of
tropical climates, are sudden in their attacks, and rapid in their
course, if any thing is to be done to arrest the fatal result, it must
be done energetically.—I  confess it is to me surprising that any
physician, practically acquainted with our  summer and autum-
nal fevers, could feel justified in treating them according to the
Broussaisan method by a  few leeches and  gum water. 
                              24
    Some  of the. followers** of  M. Broussais have had' the
*  modesty to compare «hirn\ with -Bichat.   Yes!  gentlemen,
  with Bichat,-rperhaps the most  illustrious of m(%^n medical
  philosophers.             ,      r,      ,           *\
    The splendid  genius of  Bichat, and the magnitude of his
  achievements in medical science,.have thrown into the 'ijiade
  his few defects;—yet, in common  with the  rest of humanity,
  he had his defects.  Some of the  generalizations, introduced
  by him in  the Anatomie. Generate were, undoubtedly, formed
  without that  rigid adherence to  the  spirit of  induction by
  which  we can alone hope to  impart to medicine that degree
  of certainty which can alone entitle it to the true dignity of a
  science.  But these defects in Bichat, like the spots on the sun's
  disc, are lost in the flood of  light shed by the effulgence of his
  genius.  It is only when we find these errors imitated and re-
  peated by a minor spirit;  one who, without one spark of his
  inspiration, has attempted to pass himself off as the " Bichat
  of Pathology," that we are reminded of this only infirmity of
  a noble and mighty intellect.  *
    But time admonishes me that  I must bring these remarks to
  a close.  Let me then urge upon you, gentlemen,  to  resolve
  to enter  upon the objects of this  chair—an inquiry into^the
  nature and treatment of disease—with a single purpose in view,
  —the discovery of truth.  Aware of the danger of speculation
  in Physical Science;  unawed  by  names—untrammelled by
  authority; with a modest, but manly, confidence in  your own
  good sense,  resolve to be  governed by  its dictates.   With
  such resolutions, let me assure you, gentlemen, that in the
  inductive philosophy, you hold a  talisman, which, like the spear
  of Ithuriel, cannot fail to elicit light and truth from whatever
  it touches.