M m
 
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INTRODUCTORY  LECTURE,
TO
                PHYSIOLOGY,

         DELltERED TO THE MEDICAL CLASS

                     or THE

UNIVERSITY  OF VIRGINIA;

                       BY
                             / /'
                            1/
     ALFRED  T.  M A a Z L L, Xtt. D.

   PROFESSOR OF PHYSIOLOGY, PATHOLOGY, OBSTETRICS AND
              MEDICAL JURISPRUDENCE,
                     IN THE
             DIVERSITY OF VIRGINIA.
OCTOBER 19th 1833.
M9£.^
PUBLISHED BY THE MEDICAL CLASS.
    CHARLOTTESVILLE:
PRINTED BT WATSON & TOMfUM
          1833, 

 
LECTURE,  &C«
   Gentlemen :—In appearing before you for the first time, in the
capacity of your instructor, in the highly important and interesting
branch of science, which has been allotted  to me in this University,   >N
founded  by the exertions, and  planned by the genius of our  im-
mortal Jefferson,   I feel oppressed by various and conflicting emo-
tions, which alternately cheer me with  the pleasing hope of  being
able, by  industry  and perseverance to perform my duties to your
sa'istifaction, my  own honor  and the credit of  this Institution ;  and
again sink me into despondency, from the fear of failing in all these
particulars.
   Succeeding to the Chair of Medicine, long occupied by my dis-
tinguished predecessor, and adorned  by his talents, 1 can scarcely
hope to  compensate you for his loss, except in my ardent zeal to
promote your improvement, and my firm determination to devote all
my powers, mental and physical, to the performance  of ihe high  and
important duties which have devolved upon me.  I have indeed  every
motive which ought to actuate an honorable mind, to stimulate me to
exertion and unceasing diligence in fulfilling the high and multifarious
requisitions of my office.   Your own advancement in Medical knowl-
edge, the ability with  which this chair has been heretofore  filled,
my interests and prospects in life,  which are now identified with the
prosperity and success of this University ; and last, though not least,
justice to my colleagues,  impertnvely requires  that 1  should spare  A>
no pains, and shrink from no labor however severe, in my endeav-
ours to sustain at least,if not to advance the reputation of this School.
   And  may 1 not hope that  on your part, you  will second my en-
deavours, and  sustain me in  the execution of my arduous task, by
j»n assiduous attention to the various departments of  Medicine which
it is my province to illustrate, and  your duty to learn.  It will be in
vain for me to  lecture or for you to listen, unless you give  perma-
nance and durability to what you  hear, by private study and  medi-
tation.  Lectures  may perhaps  awaken a latent propensity,  or en-
kindle a transient inclination, " but unless the  new-born flame be
fed  and fostered—unless it be nourished by study, as well as  ex-
cited by hearing, it wilJ perish as soon as lighted up; or, if it con- 
4
      linue, will only blaze forth in a foppery of knowledge far mor:
      tempiible than the grossest ignorance."
        Physiology may be defined the science of life.   Tts object  is to
      elucidate and explain the healthy functions of the system, and to as-
      certain  and  define those laws of  virtality which preside  over and
*??t^ control the "lotions of the animal economy.   Anatomy unravels the
      structure and displays to our view, the exact situation of each and eve-
      ry part of our physical frame.  Physiology expoundsthe functions, and
      explains  the particular part which each organ performs, in the healthy
      economy of our system.  In the language of Dr.  Rush,  " Simple
      Anatomy is a mass of dead matter.  It is physiology which  infuses
^^life into it.  A knowledge of the structure of the human frame oc-
      cupies only the memory.   Physiology  introduces  it to the higher
      and nobler faculties of the mind."
        And what study, let me ask you, can be more delightful to an
      intelligent mind,  than an investigation of  those  functions through
      the exercise of which " he lives, moves, and has his being ?"   What
      more pleasing task than  to trace the wisdom of our Creator in the
      formation of our body, and its admirable  adaption to all the circum-
      stances of this  sublunary state ?  What more effectual  antidote to
      the dark  and gloomy speculations of the  Atheist, than the  wonder-
      ful display of wisdom,  and  design, as exhibited especially  in the
      structure of the nicer and more delicate organs of our frame ?  In
      the beautiful organization of the eye,  there  is more than enough to
      stagger the incredulity of the most hardened sceptic; " in its sim-
      plicity of action,"too (as remarked by  an eloquent writer,)  "so
      perfect, so unspeakably  perfect, that the searches after tangible ev-
      idences of an all-wise and  good Creator, have  declared their wil-
      lingness to be limited to it alone in the  midst of millions as their
      one triumphant proof."
 €      Like all the other branches of-Medicine, physiology has  been
      slow in reaching even its present imperfect state, when the veil of
      mystery still  remains over  many of the  operations of our system.
      In the early periods ol Medicine,we find  it encumbered with a mass
      of false  assumptious.  absurd fancies and  ridiculous opinions.  It
      would be sheer waste of time to repeat them all to you.   Ignorant
      of the circulation of the blood, and uninformed as to almost every
      other function of  the body, physicians gave  free scope to their im-
      aginations, and  to use  the langauge  of an eloquent writer, " so am-
      ple an exhibition of human invention,  might gratify  our vanity  if it
      were  not more  than counterbalanced by the humiliating view  of so
      much absurdity, contradiction and falsehood."
        The discovery of the  circulation of the blood by  Harvey  about 
6
the middle of the 17th century, like the discoveries of Galileo, m
Astronomy, marks an important era in the history of physiological
science,  and like them also  meet  with the most bitter and unre-
lenting hostility.
   A vague notion of a  circulation of  blood  through  the  system,
was entertained  by various writers even  of an early date.  Servetus
who was burned as a heretic at Geneva, in 1553, approached nearer
to it  than  any  one  who  had preceded him,  and  actually  taught
what  \i called ihe  lesser  circulation, or  that through the lungs.—
Aboul a century after this,  the illustrious Harvey, established by
incontroveriible  arguments, the  fact that the arteries conveyed the
blood from the heart to eveiy part of the system, and that the veins
returned it back again to the same organ.   Like all important dis-
coveries, which tend to revolutionise and destroy prevailing opinions
and long fostered piejudices,  it was  received, not only wi»h dis-
trust, but met with  the most decided opposition  from the  physicians
of that day.   A discovery so brilliant  in its character  and  results,
and which has  been the foundation  ol all the improvements  since
made in the theory and practice of the healing an, was attempted
to be put down, simply because it  was new and irreconcilable with
their absurd notions.
    The opinion had been long  entertained, and was universally be-
lieved, at  that lime,  thai  the liver was a  sort of  manufactory of the
blood; and that it was sent out from thence by the veins, to nourish and
sustain the body; and that it circulated  from within ouiwaids during
the day, and returned at night—that the ar'eries contained air  or
animal spirits, which by  mixing with  the blood, gave animation and
activity  to the functions.   These opinions were pertinaciously  ad-
 hered to,  notwithstanding the clear  and  beautiful demonstration
of the true  circulation,  by Harvey.   They had become great and
 important  doctrines, and were to  them sacred  from  their age.—
 They had imbibed  them from  their most  distinguished teachers,
 and not only their practice, but all that they themselves had written
 and taught, were based  upon the supposed truth of these opinions.
 If the  Harveian doctrine  should  prevail, the  result would be the
complete overthrow of all their fine-spun theories, and  the  volunnfs  «<J_^
 they had written would be looked upon only as so many monuments
 of folly and ertor.  These considerations  sharpened  the  edge of
 their opposition, and gave bitterness to their hostility.
    The  doctrines  of Harvey, however as  might be supposed, tri-
 umphed over these absurdities of a barbarous  age, and dissipated
 their idle  notions about  humors, and temperaments, and  spirits and
 blood : of the blood concocted in the liver, and moving  out by day 
6
 to nourish the body, and returning during the night; and of  the arte-
 ries containing only  air or vital spirit,s to animate the  system, while
 the veins alone conveyed the proper blood.
   This important discovery  however of the  great Harvey,  as beau-
 tiful as true, failed for a long time to shed  its beneficent influence
 over the science of Medicince.   The  mind of man ever prone  to
 leave  the path of severe inquiry, and persevering  research ;  and
 generally  preferring  to adopt the suggestions of a wild and way-
 ward  imagination,  soon  began to build upon it the  most absurd
 and  visionary theories.   I shall give'you a brief and rapid sketch of
 some  of them, which succeeded each  other as wave follows wave,
 and then bring down the. history of physiology to the present time.
   The first which merits attention, is that of Boerhaave, and some
 of his  distinguished cotemporaries, which from the great eminence
 of its author as a teacher of Medicine, and  his exalted virtues, as a
 man, soon  acquired the most unbounded ascendency, and  reigned
 with undisputed  sway over the Medical world,  until  it was in turn
 supplanted  by others equally   as absurd.     Boerhaave  fancied
 that  the  blood  was composed  of particular  globules, the  lar-
 ger globules  of smaller ones,  and these  of still more diminutive
 ones;  that  the arteries  were  so   proportioned  to  the  diameters
 of these globules, ;md  descended by  steps  so  regular  and uni-
 form, that each artery  was  adapted to globules  of a certain size,
 which entered it with ease ; and that if  any of the globules, should
 in consequence of violent and  irregular action of the blood vessels
 be driven into vessels whose calibre happened to  be too small, they
 were immediately arrested,  constituting what  he termed   an error
 loci,  and giving rise 'o inflammation or general disease.
  It  is strange that this opinion unsupported  by any satisfactory rea-
sons, and with  no facts  to sustain it, should ever have  acquired  the
unbounded popularity, and universal credence, which  it once pos-
sessed.   Hundreds  from all pans of E'irope annual.'v flocked to
 his eloquent lectures, and returning  home thoroughly imbued with his
opinions  spread them  far  and wide.    Notwithstanding  all  this
 however,  his  medical  doctrines  survived  him but  for  a brief
smre.   The mere effsprina:  of  imagination,  wIipii deprived of the
facinations  of his eloquence, they  soon  defended into the  same
tomb with him, and are  now remembered only as a part of the  his-
tory of physiological science.   The fate of  Boerhaave's doctrines
affords a striking example of the truth of a remark made by the cele-
 brated  John Hunter, in one of his introductory lectures :   " Those
teachers (says be) who study to captivate young minds with ingeui- 
7
ous speculations, will leave behind them  a reputation that will  not
outlive them half a century."
   Boerhaave was succeeded by what were termed the mechanical
physiologists, who made the vain attempt to explain all the phenom-
ena of living matter, by  the application of the laws of mechanical
Philosophy.   By Algebraical and Mathematical problems they pre-
tended to calculate the exact force of the  heart; the velocity of the
blood, the form of  the arteries and the strength of the  veins, and
the shape and size of each secreting orifice, according to  the secre-
tion it had to perform.   Such were the notions promulgated by the
great men of that day, and which  rendered  famous  the names of
Beleni, Keil, Pitcairn, Hale, and other  mechanical  physicians, and
14 whose  books, as  remarked by a distinguished  writer, are long
since gone to the tomb of all the Capulets."
   They forgot in their eagerness to theorise,  and their rage for cal-
culation, that physiology is an  independent  science, resting upon
truths and regulated by laws of its own, and that living matter is not
subject  to physical laws, "neither indeed can be."  It  is true that
a  knowledge  of physics, aids us in the comprehension of many of
the functions of life; thus for  the  better understanding of the ma-
chanism  of sight and  hearing,  Physiology borrows from the sci-
ence of  acoustics and  optics, elementary  notions ol  sound  and
light, and we call in the aid of Chemistry for information as to the
intimate  nature or structure of the solids and  fluids of  the  body,
and Geometry  and  Mechanism furnish  us with the  means of better
understanding the advantagious form  of the organs, and the perfec-
tion  of  their structure.
   We have loo,  in  the organization of man  and beast,  a beautiful
example  of the application of the laws  of hydraulics, in regulating
the flow and restraining the impetus of the blood, to the most delicate
and  important organ of  the frame.  The  blood which is  sent to the
brain by  four large  arteries, and impelled with  all the  contractile
power of the left ventricle of the  heart, would unquestionably have
injured  its soft  and  delicate texture if thrown  into it  en masse.
Nature has wisely provided against this, by dividing the  blood, into
an infinity of streans, by endless divisions and sub-divisions of the
cerebral arteries before they penetrate the cerebrum.  The rcte mira-
bile  of quadrupeds presents a similar arrangement.   The assistance
however derived from these sciences is accessory merely, and does
not constitute an  essential part of the  edifice of the  science.
   The  fcience  of  chemistry,  which had  been  for a  long time
wasting its powers  in the vain pursuit after the philosophers stone
and  the  universal solvent, was at length wielded in  the cause of
philosophy* 
8
   " Having analyzed the  materials of  the  druggists, the chemists
 proceeded to analyze the parts of the human frame to which those
 medicines were applied; but from this rational commencement, fol-
 lowed one of the most trivial of all the  miserable doctrines with
 which our science has  been disgraced; for as the chemists had
 already  explained the properties of  the salts, metals, earths, and of
 all active substances by the angles, cubes or other forms which they
 saw  their  particles assume—they  soon persuaded  themselves that
 such form as cubes, wedges, specula?, existed in the blood; and acid
 and  alkaline humours, sharp, corosive,  irritating and pointed particles,
 were the terms in which they expressed  their most admired theo-
 ries: and acids, alkalies, and metals, and medicines for rounding the
 pointed particles, or obtuuding (as  they termed it) or sheathing, or
 covering the acrimonious humours, were their chief preventives and
 cures."
  Such were the spurious fruits which soon sprang out of Harvey's
 discovery of the circulation  of the blood. What might by proper use
 have been rendered a blessing to mankind, was for a time converted
 rather into a curse, by the intellectual obliquity and rage for  theorizing
 which  possessed the minds of physicians  at  that time.   Each of
 these different sects held for a short period the supremacy over the
 medical  world,  and were  looked up to by their votaries with the
 most blind and implicit faith.
  Physiology continued in this deplorable state, until the appearance
on the stage of the great Haller, who  is deservedly considered as the
 father of modern physiology.  Gifted with talents of the first order,
an industry which never tired, and  a zeal which nothing could damp,
he cultivated  science  generally with a success  which   has  been
rarely equalled, and became the  most learned  man of his  age.  To
physiology he  devoted  a  large share  of his  attention.   Unlike his
 predecessors, however,  he established  and followed  the method,
(which alone can  confer  success) of investigating  the phenomena
of the living body by observation and  experiment, and keeping all
hypothetical speculations in rigid  subjection  to  these two leading
principles.   The improvements he made in the science were  great-
 Discarding the application of physical  laws to explain the  operations'
 of living matter,  he examined  closely and enquired diligently into
 the nature of the specific powers of vitality, and was led to refer  all
 the actions and movements of the animal economy, to the existence of
 two inherent principles in the constitution of man, viz :  contractility
 and  sensibility, the one seated in the muscular, the other in the ner
 vous system.  This  with some little  modification, continues to be
 even at  tins  time the prevailing opinion.  To the action  of one or 
9
ihe other of these principles, as will hereaftei be explained, may be
referred all the phenomena which takes place in the system :  every
change, all the functions of the body are performed through their
immediate operation.
   The example of Haller, his manner of investigating physiological
subjects, the useful facts  which he was the  first to draw from the
analogies  afforded by the study of comparative anatomy, gave an
impulse to  the science  which  it has  never ceased to feel, and the
publication of his  Eltmenta Pbysiologiae, may be said to constitute
a new era in physiology.
   Since the days of Haller to  the present time, the field of  physi-
ology has  been occupied by  many and successful cultivators—Cul-
len and John  Hunter, his  more immediate  successors,  contributed
much to its improvement; the first by systematizing what was already
known, and sweeping away the rubbish of antiquity  which obscured
and disfigured it; ami the latter by the number of new and  inter-
esting facts with which  he enriched it.  His profound  work on the
blood is a monument of patient research, and originality of concep-
tion.
   Among  modern physiologists, no one stands  higher than Bichat;
possessed of great intellectual  powers, he united to them the most
unwearied industry.  He investigated the structure and  functions of
the body with a diligence and perseverance  never surpassed, and a
success which has left us but too much reason to deplore his prema-
ture and early death,cut down in the prime of life,and in  the midst of
his labors, he has nevertheless left  us  in  his works "the enduring
produce of immortal mind."   In his general anatomy, in which we
have a separate consideration of each organic tissue of the  body,
accompanied  by  many  and  interesting  physiological remarks, we
have an evidence of his genius which will last as long as learning is
respected  or science has a votary.
   Science  generally, and physiology especially, has to  deplore the
recent death of one who devoted a long life to its investigation and
the good of his fellow creatures; I mean Charles Bell, of London,
whose brilliant discoveries  in  that  most interesting but  intricate  /
portion of the  body, the nervous system, hji5"'greatly enriched the^*
science of  physiology, and added new lustre to a name already high
on the roll  of  fame.
   At the present time too, physiology is cultivated with a  zeal, and in
a manner, especially on the Continent which promises the most useful
results.  Its votaries, both  numerous and distinguished, have long
since ceased  to follow the false lights of the'^maginationf  which
had led astray and bewildered the minds of its earlier cultivators, and
adhere strictly to facts and experiments in their  investigations: and
              2 
10
witii such guides what may not be expected from their researches ?
   We have now brought down the history of physiology to the pre-
sent time, and by taking a retrospective view of the field over which
we have rapidly travelled, we may ascertain,  and by  ascertaining
learn to avoid the errors which not only long anterior but subsequent
to the discovery of the circulation of the blood, retarded  the pro-
gress of physiology,  and  clothed it  with obscurity and mysticism.
We see the fatal mistake which entered into the speculations of the
earlier physiologists, that of considering the human body as a lifeless
and  inanimate  machine, and the Consequent  endeavor to  account
for its phenomena by the application  of the laws of a single science
as chemistry, hydraulics,  &tc.  while  a union of  the laws of all
these  sciences will  fail in satisfactorily  explaining  the   simplest
function of the human body.   They  threw out of their calculation,
the existence of that great conservative principle of the  animal eco-
nomy,  life, which pervading every portion of the frame, gives ani-
mation and energy to every function  of the  body; resists and over-
comes  the laws of inanimate matter,  which  else  would soon dissi-
pate our material fabric into " thin air," and binds together the va-
rious   parts of the system  in  admirable and  harmonious  action.
The phenomena, too, presented  by living beings, vary  with the dif-
ferent periods of life.   From helpless infancy, to imbecile old age,
we see nothing but change; uniformity  belongs not to them.  How
can  mathematical formulas apply to such  variable qualities? "As
well might you enclose in a frail vessel, hermetically sealed, a fluid
subject to expansion  and of variable  bulk."
   "The abuse however of these sciences, (as remarked by a  dis-
tinguished physiologist) should not be a reason  for setting them aside
altogether.  The facts obtained from  natural philosophy, chemistry,
mechanics, geometry, &c, are so many means applicable to the so-
lution of the  great problem of the vital economy; a solution which
though, as yet,  undiscovered, should  not be considered as unattain-
able; and to which we shall approach the nearer, as we attempt it
with a  greater number of data.  But it cannot be too often repeat-
ed that he alone can hope for that honor, who, in the application of
the laws of  natural philosophy  to living  beings, will take into ac-
count  the  powers inherent in  organized nature, which  control with
supreme influence  all the acts of life, and modify the results that
appear most to depend on the laws by which inorganic bodies are
governed."
   Allow me  now to say a few words on the gieat importance of a
knowledge of physjology  to the physician, whose province it is to
conteritl with  fell disease, to resist with all  the  ensrgies of  his mind 
li
the foes of human health and happiness; and by kindness oi man-
ner and gentleness of deportment, to mitigate when he cannot cure
the "ills which flesh is heir to."  How let mo ask you, can any one
comprehend the patholgy or the nature of diseased action, when ig-
norant of the  healthy movements of our system?  The essence of
Empiricism is ignorance of the pathology or nature of disease, and
the  consequent blindness and  uncertainty of the practice, which
must be just as likely to do harm as good.  If you would avoid this
uncertainty, you must lay the loundation of an enlightened pathology,
by an attentive study of the physiology or functions of the  system
in a state of health.   This, like a knowledge of anatomy to the sur-
geon, can alone make you able and successful practitioners.   This
knowledge, and this alone, will preserve your  feelings calm, and
your judgment unclouded, in the fiercer attacks of disease, when dis-
may and alarm are pictured  in every countenance, and when the
faltering voice or trembling hands of the physician  might turn the
scale against  the patient; this alone can  give  you  that  confidence
and decision in your practice, which is so necessary an ingredient in'
the character of a practitioner of medicine.
   An excellent and learned writer, in speaking of the intimate con-
nexion between physiology, pathology, and therapeutics, says, " all
these are of high, if not equal importance.  As it is impossible for a
 workman to set about restoring a machine to order, with any rational
 hopes of success, without knowing the full intent  and nature of the
 injury it has sustained  so is it equally impossible for  him to acquire
 this knowledge, unless he has also a knowledge of the structure of
 the machine, and has studied its several  parts methodically, and in
 reference to the bearing which one part has upon another."
    In order to see a practical illustration of  the bad effects of a want
 of physiological knowledge over the healing art, we need only carry
 our  views  a few  centuries back, and  although we may meet with
 some truths,  and  sound rules of practice, yet we shall discover a
 mass of error and absurdity, almost disgusting to an enquirer in this
 comparatively enlightened age.   We perceive the best minds wan-
 dering in darkness and uncertainty,  with scarcely a gleam of light
 to direct their  course, anxiously endeavoring to find the right way,
 but as often led by chance  into the wrong.  But it is unnecessary
 to press this  part of the subject farther; it must be obvious that me-
 dicine in all  its parts cannot but be enlightened  by physiology. Ow-
 ine to ignorance or neglect of it the art of healing long remained in-
  volved  in a mist of conjecture and hypothesis; and  it is physiology
  which has been the guiding star of the profession in  its onward and
  at present rapid march of improvement.
VN* * 
12
         In your investigation of physiological subjects, both now and here-
       after jet me recommend to you.not to limit yourself to what is already
       known; cultivate it with a view to discovery ; explore the terra  in-
       cognita  of the  science ; let  experiment and  rigid observation be
       your guides,  ever  remembering,  that  the  reveries of Stahl  may
       amuse, but  the experiments  of  Haller alone  can  instruct;  and
       your reward may be the blessing of  thousands  ready to  perish,  for
       light shed upon some  at present obscure and fatal disease.  " The
       path of science  is  open  now to every variety  of age,  and  almost
       to every variety  of education. Thousands at this moment behind, are
       pressing forward, and will suipass those that  are before; and the
       richest and most gratifying  reward  I can ever receive, will  be  to
       find  that  many  to whom  this course  of study  is delivered,  will
       hereafter be able to communicate  to me the same proportion of  in-
       formation, which it  is my duty to suppose I can at present commu-
       nicate to them."
*    ,    In  the  study of man, " distinguished link in being's  endless
TA*n\ikMA(," we cannot but  be led to admire and adore  the wisdom,
       power, and goodness  of that  being  who has formed and  fash-
       ioned us  thus  ;   who  has  spread  around   us the  beauties  of
       creation in  rich  abundance, and furnished us with senses for enjoy-
       ing  them;  and above all, has bestowed  upon us the  high capaci-
       ty  and  exclusive privilege of "knowing, loving, and serving him."
       Man is indeed  the noblest work of  God.  In  beauty and symetry
       of form, in perfection of structure, and elevation  of bearing, no other
       created being can compare with him.  ' Os homini sublime dedit, cce-
       lumque tueri.' To man God gave an upright countenance, and to sur-
       vey  the Heavens.   Oiher animals move  in an horizontal posture.
       In none of  these are the senses  possessed  of the  same degree of
       perfection.   Not one of thern so admirably provided   with organs
       to keep up  an intercourse, as a living being, with surrounding ob-
       jects.  The eagle,  proud emblem of our country, whose sight is s
       keen and piercing, possesses a very dull sense of touch,taste and smelL
       The dog, who is endowed with a most exquisite sense of smell, has
       hut a limited sphere of vision ; in him the taste and touch  are equally
       imperfect.   In man all the senses are exquisitely developed.  The
       sensitive centre  in  no  one is  better displayed, and fitter to direct
       safely the use of the organs of motion ; no other animal can articulate
       vocal sounds, so as to acquire speech.
         The striking  superiority of man,  however, is to be found in  his
       intellectual attributes.  Born into this world, the most helpless of liv-
       ing beings, he rises superior to natural defects, by the force of his in-
       tellect, and becomes fitted to exercise dominion " over the beasts 
IS
of the field, and the fowls of the air."  What has not human genius
accomplished?  What is it  not daily accomplishing?   If we look
to the land and  to the sea, we shall every where behold the evidences
of itsp >wers and the imperishable monuments of its greatness. What
would have been  the state  of this  mighty and teeming continent,
had  not the mind of a Columbus suggested its existance, and con-
ceived the bold plan of its discovery ?   What but his intellectual en-
ergies could have sustained and supported  him through the'difficul-
ties  of his mighty  task,  with nothing to direct his coursa save his
compass, and  the  stars which gleamed  over his traokless and soli-
tary   way.
   But man's proudest and noblest  distinction, is  the  life he is  to
live, when  this  world shall be to him, as though it had never been.
He possesses a principle within which tells him of immortaility, and
points him to an endless  existence in another world.  The dark and
chilling creed, which teaches that man is dust, and that ihe grave  is
his only  and  final  home, is at war with  all  our feelings,  hopes, and
aspirations, and  is Ibieign  to the  nature of  man.  He feels  that
he is destined io take root in another soil, to  be  warmed   by  an-
other  sun,  and  to be  nourished   by  other  food.   Human rea-
son  extends  not beyond the limits of this  world,  but revelation
informs us that it is a change  fraught with good unutterable, or evil
intolerable, as ihe case may be.  To the Book of Books I refer you
for  infallible directions  how to attain  to the one and to avoid the
other.  Do hut  follow  them, and  you are certain  to go right.   I
cannot  better close this part  of my lecture, than in the expressive
words of the poet—"How complicate,  how wonderful is man, how
passing wonder  He who  made him  such !"
   In  conclusion, allow me  to  offer you some advice as regards vour
studies.  You have, gentlemen, entered upon a profession of high
and difftVulty attainment; a profession  not  surpassed by anv other
in ils elevation  and bearing  on the welfare  of society.  Not the
happiness of  individuals  alone, but  the health, ihe happiness,  the
well  being  of nations ;  the body, the mind, are  all  involved in the
science of  Medicine.  Indolence or inattention therefore in quali-
fying yourself to  discharge  ihe important  duties of a physician,  is
not only disreputable but criminal.   And let  me assure you, thai  it
is here, in  the calm retreats of science, where you have leisure for
study and  profound investigation,  that you  must, if ever,  lay the
foundation, upon which to erect the super-structure of your  future
fame and usefulness.  Il is here that yon  must garner up in the store-
house of your mind, the  pabulum for future reflection, and the ma-
terials for future discoveries and inventions; and he who whose men- 
I i
tal armory is best furnished with'facts and information, when he en-
ters the world  and mingles in its strife for fame and fortune, will be
best qualified to win success, and profit  by the observation  and ex-
perience there to be obtained.  This  foundation can onlj  belaid,
this knowledge can only be acquired,  by diligent and  persevering
study of the science of  medicine; a science difficult beyond  most
others,  and requiring  for its mastery not only high mental endow-
ments,  but various  and extensive  learning.  To the profession of
medicine,   the palm of learning, has been assigned  by Dr.  Parr,
himself, the most learned man of his age, and by Jefferson, Doctor
Johnson and others not less distinguished.
   Let me beg you, then, to press forward, with  industry and perse-
verance in the acquisition of knowledge.   They are the magical keys,
which will unlock for you the portals  of the temple  of  science, and
conduct you  into its inmost recesses; and they alone will enable
you to climb the steep ascent, "where Fame's proud temple shines
afar."  Let the science of medicine  therefore be the chief subject
of your meditations;  let its volumes be constantly in your hands.
"Nocturna versate manu, versate diurna."
   And in   thus acting you  will not  only comply with the demands
of duty, but consult your own  happiness.   Independent of the ap-
probation of your conscience, which such a courseof conduct will cer-
tainty give you employment of mind or body, or both is absolutely ne-
cessary loour happiness here.  The idle  are never happy—with them
the society  of  tne gay and dissolute is indispensable to comfort, and
too often, alas! the excitement of the bottle becomes the  ruinous
and hateful substitute  for the healthy  stimulus of  mental employ-
ment.  In the intoxicating cup they find a remedy,  bad and tempo-
rary  though it be for the distressing  ennui of idleness  and the un-
equalled misery  of  doing  nothing.   Well and truly has  the Prince
of modern Poets said—

             "The keenest pangs the wretched feoJ,
             Are  rapture to the dreary void,
             The leafless desert of  the mind,
             The waste of feelings  unemployed."

   Let me also earnestly advise you, at the same time that you pay the
 necessary regard to other branches of knowledge,to bestow your chief
 attention upon that pursuit which is to be the employment of your life.
 Non omnia possumus omnes: we cannot excel in every thing.   The
 powers of the mind, like the rays of the sun, to act with vigor and
 effect, must be concentrated; when dih t?d  by too much expansion,
 they lose  their  efficiency and become comparatively  feeble, hence
 wc find that  all the important discoveries in science and  usrful in- 
15
ventions  in the  arts, have  been  the  result of this undivided and
steadfast action  of the mind upon one objector branch of science.
It  was  this singleness of object  and untiring devotion to one pur-
suit, that enabled  the sublime and mighty  intellect of a Newton to
unravel the glorious mechanism of the heavens; to trace the stars in
their courses, and to calculate with precision  the  rapid flight of the
cornet, " shaking  from  its horrid hair  pestilence and  war;" with
him it was the burning passion of his soul, all other occupations of life,
nay, even the very passions of humanity, were sacrificed at the shrine
of his  devotion.  It was this which enabled that great  philosopher
and incomputable man,Locke,to sound the depths of the human intel-
lect; to analyze  its operations, and establish its properties.  By this
intense action of the mind  on one subject, Watt discovered and ren-
dered  subservient  to  the  arts and comforts  of life, the miraculous
powers of steam.   How incalculable the  benefits, how wonderful
the results of this  sublime discovery?   "The name of  Watt will
float on the breath of  fame, while the unconquered  arm  of  steam
continues to widen  its dominions, or history  to record the achieve-
ments of genius."
   Follow then the example of these great and eminent men—select
your profession  and pursue it with a  zeal which nothing can  damp,
and a  perseverance which will overcome all  difficulties, and you
will thus fulfil the fond hopes and expectations of parents—do cre-
dit to yourselves—justice to your teachers, and reflect reputation
upon your Alma Mater. 
 
 
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