184B

r*-1*!-'*' »^[»W»S-■"» u --. -v\-\ , • -

a#

llii^!#»: /■•:::■  ..■:•-■
m^M)^l^\,::y-:    ■.■;->-:.■

 mMr%wWW-W-:-:'<■■■■'    "


       x(:^';m^'- r ■'.■• - .  ..
fe
V;'S*» 
UNITED STATES  OF AMERICA
** ♦  »
FOUNDED  1836
WASHINGTON,  D. C.
GPO  16—67244-1 
 
 
AN
INQUIRY
INTO THE
DEGEEE  OE CERTAINTY IN  MEDICINE;
AND INTO THE
NATURE AND EXTENT OF ITS POWER OVER DISEASE.
       ELISHA jBARTLETT,  M.D.,
PROFESSOR OF THE THEORY AND PRAbTICE OF MEDICINE IN TRANSYLVANIA UNIVKBSITT;
      MEMBER OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES,
                 ETC. ETC.
fithr'T-
       PHILADELPHIA:
LEA  AND  BLANCHARD
            1848. 

  Entered according to the Act of Congress, in the year 1848, by
                 LEA AND BLANCHARD,
in the Clerk's Office of the  District Court for the Eastern District of
                       Pennsylvania.
w
■A
Ml
         PHILADELPHIA:
T. K. AND P. G. COLLINS, PRINTERS. 
TO
      MY BROTHER,  GEORGE BARTLETT,
                OF WOONSOCKET, RHODE ISLAND;

To whose  acute and comprehensive mind my own is greatly
indebted for many of its clearest views and its strongest  con-
victions of philosophic truth; and to whose genial and sunny
companionship  my life owes many of its pleasantest and hap-
piest hours, this little volume is affectionately inscribed.
  Woonsocket, Rhode Island,
   September 1st, 1848. 
 
PKEEACE.
  The main title of my inquiry is the same as that
of the very elegant and classical essay of Cabanis,
published half a century ago.  I  adopt it  for the
simple reason that there is no other at all appro-
priate.  Since writing my own essay I have read,
for the first time for nearly twenty years, the work
of Cabanis.  Besides  the  differences that must
almost unavoidably exist, in the conception  and
treatment of a  complex and difficult question by
different minds, I may be permitted  to say,  that
the leading and principal design and purpose of
the two works are not exactly identical.  The essay
of Cabanis is more elementary than my Inquiry is;
it deals more systematically with the fundamental
nature and  philosophy of medicine, than  my In-
quiry does.  The latter may be said to take up the
subject where  it is left  by Cabanis.  I  have no
pretensions to  supplant, or to rival, the finished
and beautiful essay of the French philosopher and
physician; and the unlikeness of the two works is
at least sufficient to save me from the imputation 
VI
PREFACE.
 of having merely repeated my forerunner,  or  of
 having merely gone over the same ground.
   Some of my readers, especially the more staid,
 and older ones—my esteemed and venerable seniors
 and cotemporaries—may think, perhaps, that I have
 now and then suffered myself to  be  seduced into
 dangerous proximity to  the boundary line, which
 separates good taste and simplicity from their op-
 posite  qualities.   If I have done so, it  has  been
 from yielding to an impulse, excited  and kindled
 by the task  in which I have been engaged, and
 which I found it difficult to resist.  If the drapery
 of our philosophic muse wears a somewhat warmer
 and  livelier  hue, than the sober  coloring which
 more appropriately belongs to it, it has been caught
 from the sunny fields through which her pathway
 has lain.   If the  axle of our car has now and  then
 waxed fervid, and if an occasional gleam of light
 has flashed from its flying wheels, let us at  least
 plead,  in extenuation  of  the weakness, that  it is
 not from  the careless  rein, or any perilous speed
 with which  our  coursers have  been driven, but
from the glowing and radiant atmosphere through
which we have been carried along.
   There may, possibly,  be others who will say
that my advocacy of the claims of medicine is more
zealous and earnest than is becoming in one of its
practitioners and  teachers.  I can only answer, that 
PREFACE.
Vll
I do not think so.  I speak for the art and the sci-
ence, not for  myself.  This art and science have
been violently, and I think, blindly and  unjustly
assailed, by parties who understand neither their
own strength and position, nor ours.   I have en-
deavored to  make fair and manly stand against
them, and I have done nothing more. When crowds
of epauletted and bedizened coxcombs, who have
never smelt  gunpowder, make the air  clamorous
with their noisy boastings, the war-worn and scar-
covered veteran may, at least, point to the trophies
that he has brought from a hundred battle-fields. 
I
I 
AN  INQUIRY
DEGEEE OE  CERTAINTY IN MEDICINE.
  I am stating only what everybody knows to be
true, when I say that the general confidence which
has heretofore existed in the science and art of me-
dicine, as this science has been studied, and as this
art  has  been practiced, has within the last few
years been violently shaken and disturbed, and is
now greatly lessened and  impaired.   The  hold
which medicine has so long had upon the popular
mind is loosened;  there is a wide-spread  skepti-
cism as to its power of curing diseases, and men are
everywhere to  be found who deny its pretensions
as a science, and reject  the  benefits and  blessings
which it proffers them as an art.
  It is not  necessary, for my present  purpose, to
point out the causes and influences which have led
to this state of  things.  I will merely say, in this
connection, that however trifling and inconsidera-
ble  may have been the effects upon the feeling to
which I have alluded, of the famous article of Dr.
Forbes, first published in the British and Foreign
Medical Review, I give utterance, I suppose, to the 
10
AN INQUIRY INTO
almost universal sentiment of the profession, when
I express regret that the author of that article did
not accompany his official and voluntary confession
of medical delinquency, incompetency, and uncer-
tainty, with the qualifications and conditions abso-
lutely essential to the truth of the confession itself.
This, Dr. Forbes  has almost wholly neglected to
do.  Without entering into any elaborate criticism
of his paper, it is quite safe to say, that he has taken,
if not a distorted, at least a partial view of his sub-
ject; he  has looked at one side  only of the shield;
one hemisphere only of his world of truth has been
turned to the  sun.   Now, this partial view is ne-
cessarily a false view: it is false because it is partial,
—if  for  no other reason.   Dr.  Forbes has drawn,
in strong and  exaggerated colors, the manifold im-
perfections of medical science, and the discouraging
uncertainties of medical art; but he  has neglected
to show  the limits of these uncertainties, and to
circumscribe the boundaries within  which  these
imperfections  are confined.  This he should have
done, and not only would his second  picture have
constituted,  on the principle of contrast, often fol-
lowed  by artists in such matters, an  appropriate
companion to his  first,—the clearer  and more ra-
diant sky, the steadier and serener light, the  erect
figures with hopeful and forward-looking faces of
the former, brought into striking and beautiful re-
lief by the cloudy and uncertain horizon, the murky
and  dim atmosphere, and the  constrained  and
groping shapes of the latter,—but more than this:
his first  delineation is a true  one only when the 
      THE DEGREE OF CERTAINTY IN MEDICINE.    H

second hangs by its side; the harmony of the lights
and shadows, and the truthfulness of the objects in
each picture, are dependent upon the  presence of
the other.
   The canvass, which now  stands upon my easel.
is placed there to receive, at least the outlines, and
some of the leading and more prominent  features
of this second picture.  I have waited, I think, long
enough, for Dr. Forbes, or for some one else better
qualified than  myself, to do the work which I have
here undertaken.  If Ulysses is not present in the
field to bend his own bow, some weaker arm from
the camp must essay the enterprise.   It seems to
me high time, that a clear and earnest word should
be  spoken for the science  which  we study and
teach, and for the art which we inculcate and prac-
tice.  The interests of truth, of our profession, and
of  humanity, alike demand that  the legitimate
claims of medicine to the regard and confidence
of mankind should be vindicated and maintained.
And this is the task I have set myself.  I  wish to
show as clearly and as positively as I can, the nature.
and the degree of the certainty that belongs to medi-
cine as a science, and as  an art.   In doing this, I
shall deal but little in general  assertions, unsus-
tained by positive proofs, and not at all in empty
and vague declamation; I shall state the reasons of
the faith that I profess, and I shall exhibit the evi-
dence upon which it rests.
  Anatomy, constituting one of the great primary
departments of medical science,  stands in no need
of any vindication; it has  never been accused of 
12
AN INQUIRY INTO
any  want of positiveness and certainty;  it has
never been upbraided on account of its weakness
and imperfections.  Like its analogous and kindred
branches of natural history  concerned with the
structure and composition of the other various forms
of matter, its investigation is beset by few of the
difficulties which are connected with the study of
the laws and phenomena of  the living organism;
and like these branches, it has, for a long period of
time, been  steadily advancing towards perfection.
We have a right, I think, to contemplate this sub-
ject, not merely with some degree of complacent
satisfaction, but with  justifiable  exultation  and
pride.  The more  obvious  and coarser structure,
so to speak, of the several parts and organs of the
human body, has, for along time, been pretty accu-
rately known ; but within the last fifty years, and
especially within the last twenty-five years, through
the aids furnished by the microscope and by che-
mistry, the more recondite and elementary portions
of this structure have been brought to light.  Not
only has every bone and every muscle of the body
been  named  and  numbered and minutely de-
scribed; not only  have all the blood-vessels  been
traced through their most delicate ramifications;
not  only have  those attenuated  and  gossamer
threads of pearly tubuli, through whose subtle and
 mysterious agency the  central  and  indivisible
 spiritual  essence  which we  call the soul, holds
 communion with  the  body to which it  is tempo-
 rarily united, and with the material universe, been
 followed through  all their intricate windings and 
      THE DEGREE OF CERTAINTY IN MEDICINE.    13

their complex intertwinings with each other, from
their starting points in the nervous centres to their
ultimate  terminal loopings in every part of the
body;  not only has the doubtful duplicature of
every arachnean  membrane,  almost  and  under
many circumstances altogether invisible, from its
excessive thinness and its perfect  transparency,
been unfolded; not only have the gauge and mea-
surement of the  blood globules been  accurately
taken; but the progressive development of the
organic tissues has been closely and  assiduously
followed, step by step, through all their successive
changes  and transformations,  from  the rude and
simple elementary cell with its nucleus and nu-
cleolus, up to the highest  and most finely elabo-
rated  structures of the organism.   Even the pri-
mordial embryotic atom has been seized, almost at
the moment of its inception, and a corner of the
veil which hides the mystery of the creative energy
been raised.  Not only is all this, and much more
that I might say of the same character, strictly and
literally true, but as the  astronomer is able, from
the elements of the  circuits  which  the planets
of our system  are now making round the sun, to
assign to them the respective places which they
held in the heavens thousands of years ago,—so the
comparative  anatomist, guided by  the unerring
light of certain correspondences and harmonies of
the animal  organization, is also able,, from  some
paltry fragment of a crumbling bone, dug from the
earthy or calcareous bed where it had lain for ages
whose duration can be neither measured nor ima- 
14
AN INQUIRY INTO
 gined, to  recreate the individual to which it be-
 longed, and to  know as a cotemporary  Buffon or
 Cuvier might have known, all its habits and eco-
 nomy.  "A geologist," in the words of one of my
 friends—anatomist, physician, philosopher, poet,
 and wit—" hands to his physiological friend, a par-
 ticle  broken from a fossil tooth, and requires  the
 nature, size, habits, food, date, of the behemoth, the
 megalosaurus, the palasotherium that chewed upon
 it.  The physiologist grinds a speck of it down to a
 translucent lamina, saturates this shaving with the
 light from a  little concave mirror, screws  his in-
 exorable lenses to their focus, and extorts a truth
 which nature had buried beneath the deluge and
 blotted with the night of uncounted ages."
  Remarks,  very similar to the  foregoing, with
 certain abatements  and  qualifications,  may be
 made in regard to physiology, the second great de-
 partment of medical science.   The functions  of
 nearly all the  organs and tissues of the human
 body have been more or less positively and com-
 pletely ascertained.   The properties of the bony
 framework of this animal mechanism, the strength
 and resistance  of its plates, its cylinders  and its
 arches, areas well known as those of the parts of any
inanimate machine.   The power and direction  of
the muscular forces, in all their thousand-fold com-
binations,  have been  nicely  and  accurately mea-
 sured; we have traced the two antagonistic and
ever-moving currents of reparation and decay, fol-
lowing the materials of nutrition through their va- 
       THE DEGREE OF CERTAINTY IN MEDICINE.    15

 rious metamorphoses to their final incorporation
 with the tissues, and thence again out of the body,
 when they had fulfilled their appointed but tem-
 porary mission; we have tracked the course of the
 blood through its double and interlocking circuit;
 we understand as well  the play and action of its
 central propelling apparatus, as  we  should if it
 were working, naked, and transparent before us;
 we know the exact moment when its several ca-
 vities  contract and  dilate, and when its delicate
 and nicely adjusted valves open and  shut;  we
 can see  the same fluid put  on  its scarlet color-
 ing in the lungs, woven by the  fanning atmo-
 sphere with which it here comes in contact, to be
 put off again in the remote network of the capil-
 lary vessels; we  can  watch  the rapid alternate
 motions  of the ranks  of microscopic cilia wav-
 ing, long after all other signs of life  have ceased
 to exhibit themselves, like the green  grass  or the
 golden grain as the fresh breeze of  the summer
 passes over them; we  have raised, at least a little
 way, the veil which hides the subtle and wonderful
 processes of our spiritul nature,—we have traced
 the power of thought, the capability of emotion,
 the consciousness of impressions received from sur-
 rounding objects to their connection with  the  ve-
 sicular matter of the brain; and we know the chan-
 nels along which these impressions are transmitted,
and those which  carry, in an opposite  direction,
the stimulus of the nervous power, and the man-
dates of the will.
  I do not mean to say by these remarks, that the 
16
AN INQUIRY INTO
sciences  of anatomy  and physiology are by any
means finished and complete; this  can hardly be
said of any subject of human inquiry.  I  mean
merely to say that this degree  of completeness is
as satisfactory as it is in any of the natural sciences,
and that it  is daily advancing.  There are impas-
sable barriers to our investigations into the secrets
of nature, whatever maybe their character or direc-
tion; and here, as elsewhere, we are surrounded on
all sides by a ring of darkness which  no power of
ours can ever penetrate  or  dispel.   But we may
rest assured that here, too, as elsewhere, all that is
knowable will be known.   Every passing month
furnishes its contribution to the work; some new
discovery is made, or some old truth is strengthened
and illustrated, or some  error or  delusion  is cor-
rected  or dispelled; a thousand microscopes  are
prying into the deepest and darkest  recesses of or-
ganization; a thousand laboratories  are busy with
the chemistry of life; myriads of patient scalpels
are plying  their careful  and laborious dissections,
and  so these, like  all other branches of human
knowledge, are carried slowly but steadily forward
in their interminable career.
  It is not, however, against these departments of
our science that the accusations, to which I have
alluded, have been brought, so that  there is no oc-
casion  for my giving to them anything more than
this general and passing notice.  It is unnecessary
to make a formal defence of a point which is never
attacked.   The charges of which I have spoken,
refer particularly, and almost  exclusively, to that 
       THE DEGREE OF CERTAINTY IN MEDICINE.    17

 department of medical science, designated by the
 terms pathology, and therapeutics.  This department
 is constituted by the phenomena and relations of
 disease; it embraces all these phenomena, and all
 these relations.  It professes, and claims to consist
 of, a knowledge of the causes of disease,  of the
 seat and phenomena of disease, and of the  means
 of preventing, mitigating, and removing disease.
 The  charges  against our science are,  that it de-
 ceives itself in this matter,—that its pretensions
 are either altogether false, or greatly exaggerated,
 —that its knowledge of disease is vastly less than
 it professes to  be,—and especially, that its  power
 of curing and of mitigating disease has been im-
 mensely over-estimated and over-stated.    These
 charges  sometimes deny altogether the existence
 of this power, although, in  most instances, they
 content themselves with the allegation that it is
 very limited in extent, and very uncertain in  its
 application.
   These are grave charges, and I think they should
 be gravely met; they strike at the very foundations
 of our science, as a power and means for removing
 and diminishing the physical ills  of life; they rob
 it of its chiefest grace and glory;  they take away
 its highest claim  to  the regard  and gratitude of
 men; they deserve, I think, an honest and thorough
 investigation;  and this investigation, subject to the
 conditions  of the  space within which  I wish  to
 work, and the ability with which I may be enabled
to work, I now proceed to undertake.   I shall en-
deavor to show the  nature  of our knowledge of
    2 
18
AN INQUIRY INTO
 disease—its extent, and its degree of positiveness ;
 I shall endeavor to show how far, and with what
 measure of certainty and of constancy, we are able
 to control, to mitigate, and to remove disease.
   The best way, and, indeed, the only way, within
 the limited space which I have assigned myself, in
 which I can do this, is to rely principally upon the
 evidence  and illustrations which may be derived
 from the study and examination of some individual
 disease.  This disease, in order to answer my pur-
 pose, should be of frequent occurrence, not confined
 to any particular localities, susceptible of being
 clearly marked  in  its characteristic features, and
 sufficiently severe, more  or less seriously  to en-
 danger life.  I do  not know any acute affection
 that so nearly fulfils all these conditions, as pneu-
 monia, or  inflammation  of  the substance of the
 lungs; and I shall accordingly make use of this
 disease, in the further prosecution of my subject.
 It is only important for me to add here, in order to
 remove any suspicion that may arise in the  minds
 of my  skeptical readers, that I have chosen  a one-
 sided, and an unfair subject  for the illustration of
 my inquiry, that after having gone through with
 this detailed  and special  illustration, I intend  to
 point out the differences which exist between this
disease  and others, whether these differences are
in my favor or against me.  I shall strive not only
to tell the truth, but to tell the whole  truth.
 There are several forms or varieties of pneumonia;
it is necessary for me to state here, that in the use
which  I propose to make of this disease, I shall 
       THE DEGREE OF CERTAINTY IN MEDICINE.    19

 confine myself to its ordinary sporadic form, occur-
 ing in persons after the age of puberty, and at the
 period of attack, in the enjoyment of,  at  least, an
 average degree of health, and free from any  other
 obvious disease.
   The first inquiry that  presents itself relates to
 the local lesion which constitutes, anatomically,
 the disease.   What, and  how much do we know
 of this lesion ?—of its  seat, its phenomena, its na-
 ture ?  What  are the foundations, the nature, the
 extent, and the degree of certainty, of our know-
 lege of these things ?  The answer to these  ques-
 tions is at hand; it is definite, and it is sufficiently
 satisfactory.   We know that with the  commence-
 ment of the inflammation, the portion of lung which
 is the seat of this  morbid action, becomes  of a
 deeper red color than it has in health, with a livid
 or violet tinge; that its specific gravity is increased,
 from an undue accumulation of blood in its vessels,
 and a corresponding diminution of air in its air-
 cells; that it has lost, in a great degree, its spongy
 and elastic feel, and is more doughy and  solid to
 the touch;  that it is less tough, and more friable;
 and that when  cut or torn, a large quantity of red-
 dish, turbid, and frothy fluid flows from the sur-
 faces.   We know that except in  a very small
 number of cases, in which this stage of engorge-
 ment continues until the subsidence of the disease,
 in the course, generally, of from two to five or six
 days, the diseased lung  undergoes other, and  still
more striking changes.   Its specific gravity is still
further  increased, so that it  is as heavy and solid 
20
AN INQUIRY INTO
as liver;  it contains no air and does not crepitate;
its air-cells are obliterated; its surfaces, when cut
or torn, are  of a deep red color, often mottled,  or
marbled;  a  reddish, thick, opake, and semi-puru-
lent fluid flows from them in moderate quantity,
and they are  crowded with a multitude of small,
red, slightly flattened, granulations.   When the
disease does not destroy life, this condition of the
lung, after having persisted for a few days, gradu-
ally disappears, and the lung  as gradually returns
to its former state.   In a few fatal cases, death takes
place while  the lung  is still in  the condition just
described; but in a large proportion of these cases,
it becomes  soft, and  still more friable, and from
violet-red, it becomes of a grayish,  or yellowish
color.  Such are the characteristic anatomical phe-
nomena of this local  lesion.   They are very con-
stant, with the conditions that  have  been stated,
and they have been  ascertained with entire and
absolute positiveness.  A certain class of physicians
—I mean the homoeopathists,—deny the value and
usefulness of  this  knowledge, but no one doubts
the certainty of the knowledge itself.
  The lesion that  I have described may involve at
the same time, or  successively, both lungs, but  in
a large majority of instances, it is confined to a
single lung, and it occurs much more frequently
in the right  than in the left.   Of fourteen hundred
and thirty cases, collected from reliable observers
by Grisolle, the inflammation was limited to the
right side in seven hundred and forty-two; to the
left in four  hundred  and twenty-six;  and it  ex- 
      THE DEGREE OF CERTAINTY IN MEDICINE.    21

tended to both  in two hundred  and sixty-two.
Every portion of the lung may be the seat of the
lesion, but the latter occurs more frequently in the
lower, than  in the upper lobes; the  right upper
lobe is more frequently affected than the left, and
the anterior  edges of  both lungs are more  con-
stantly exempt from the disease than any other
portions.  The inflammation is, in most instances,
progressive,— that is, it extends from its original
seat to other, and new portions of the pulmonary
tissue; this progression is usually gradual,—some-
times it takes place suddenly.   When pneumonia
is double, that is, when both  lungs are involved,
the second is almost invariably attacked,  not si-
multaneously with the first, but in from four days
to a fortnight afterwards.
  I cannot see why our knowledge of the patholo-
gical anatomy of pneumonia, thus briefly indicated,
should not be considered, in a good degree, satisfac-
tory.  I do not pretend that this knowledge is per-
fect, and complete.  It is at least exceedingly diffi-
cult, it may be, in the nature of things, altogether
impossible, for  instance, to ascertain in what  pre-
cise tissue  the inflammatory process  commences,
and in what minute molecular changes and per-
versions it consists.  But this kind of imperfection
belongs to all natural science; as much, for instance,
to the science of  chemistry as to  that of life.   I
will only add, that the other elements of the pa-
thology of pneumonia,—the accompanying inflam-
mation of the pleura; the change in the composi-
tion of the blood;  the striking and singular accu- 
22
AN INQUIRY INTO
 mulation of solid masses of fibrine in the cavities of
 the heart, in a certain proportion of fatal cases; the
 occasional,  but very rare, formation of a distinct
 abscess in the lungs; the varieties of the lesions at
 different  periods of life, and under other circum-
 stances, have all been ascertained as carefully, and
 as positively, as the more essential and  character-
 istic phenomena that I have described.
  In the second place, the symptoms of pneumonia,
 the  general and local signs  by which it  manifests
 itself, and reveals its presence, are not less  accu-
 rately and positively known.  In about one  quar-
 ter of the cases, the formal access of the disease is
 preceded for a few days by various disturbances of
 the  system, usually of moderate severity; in the
 other three quarters, the disease  commences sud-
 denly, without any  premonition.   The  initiatory
 symptom  in most cases is a chill, accompanied,  or
 immediately followed by, pain in the side, more  or
 less  acute; cough;  dyspnoea; a feeling of general
 uneasiness; headache ; febrile excitement; and the
 expectoration of viscid, tenacious, frothy sputa,  of
 a uniform brick-dust color.  The duration of these,
 and  of all the other symptoms,  their constancy,
 their varieties in degree and  in kind, their import-
 ance and  value, as diagnostic and as prognostic
indications, their differences and  peculiarities in
different forms of the disease, have all been  very
carefully studied, and very accurately determined.
To  give  the  results  and details  of all  these re-
searches would be, so  far, to write an  elaborate
monograph upon pneumonia; but this is not my 
      THE DEGREE OF CERTAINTY IN MEDICINE.    23

purpose, and I must content myself with the fore-
going general, but distinct and unqualified assertion.
Reside these rational symptoms, as they are called,
there is another class of phenomena, of a peculiar
character, constituting evidences of the existence,
the seat, and the stage of the disease, still  more
conclusive.  These are the physical signs, as they
are called, of pneumonia.  They consist in certain
modifications of the resonance of the walls of the
chest, corresponding to the  diseased lung, on per-
cussion ; of the  natural sounds of the respiration
and the voice, heard when the ear is applied to the
chest, and in the presence  of other sounds of a new
and unusual character.  By the aid of these acous-
tic  phenomena, we  can fix upon  the exact portion
of the lung which is the  seat of disease; we can
mark  out  its  boundaries;  we  can  follow  these
boundaries inch  by  inch, as they advance, and in-
vade  new parts  of  the  lung; we can follow the
natural progress of  the inflammation from its first,
to its second period, and  back again  in its retro-
grade march towards health.  We know the pre-
cise moment of time, when  the air-vesicles are so
blocked up, that no air passes into them, and the
precise moment, also,  when they are again opened
to admit it.  The roar of conflagration does not
mark more clearly,  the passage of the raging ele-
ment from chamber to chamber of a burning house,
than  does  the  fine dry crackle of the crepitant
rhonchus, the presence and march of inflamma-
tory engorgement of the lungs.  It cannot be ne-
cessary for me to pursue this branch of my subject 
24
AN INQUIRY INTO
 any further;  certainly, I have said enough to con-
 vince the most skeptical of my readers, if they be-
 lieve what  I say, that there is  no lack of certainty
 and positiveness, in the signs by which pneumonia
 is revealed  to us during life.
   Pneumonia is a  grave affection, and one that
 frequently  destroys life.   The degree of danger
 wThich attends it, the circumstances which increase
 and diminish  this danger, and  the signs by which
 this increase and diminution are indicated, are all
 very accurately ascertained.  One of the  most
 striking and obvious of these circumstances is the
 period of life at which the disease occurs.   From
 puberty to the age  of thirty, the danger is slight,
 and the mortality  small;  under  anything like
 prompt and judicious management, certainly not
 nore than one case in fourteen, and probably con-
 siderably less, terminating in  death.  From the
 age of thirty, onwards, the danger  and mortality
 increase with great regularity, and after the seven-
 tieth year of  life,  more than  half the cases are
 fatal.  Again, the probabilities of a fatal termina-
 tion are increased by a feeble and  delicate  consti-
 ence in the use of alcoholic drinks.  Inflammation
 tution, and especially by previous habitual indulg-
 of the upper lobe is  more dangerous than inflam-
 mation of the  lower, and there is some reason to
think that the  disease is somewhat graver in the
female than  it is in the male sex.  The previous oc-
currence of  the disease  in the same person seems
also to increase in some degree  its danger.
  Furthermore, the character of the several symp- 
      THE DEGREE OF CERTAINTY IN MEDICINE.    25

toms and their  various combinations, have  been
very accurately appreciated, as signs of the degree
of danger of pneumonia, and  as  indications of its
probable termination.   Finally, there are  certain
forms of the disease in which the  danger is very
greatly augmented; and this danger varies also very
considerably with certain prevailing tendencies, or
epidemic constitutions, as they are called, existing
during certain periods of time, and  then changing
or disappearing.
   I must content myself with these general state-
ments in regard to  our  power  of  estimating the
danger  of pneumonia.  There is no doubt what-
ever in regard to their truth.   I do not mean to say
by this, that in any given  case of pneumonia, the
physician is ever  able to for tell, absolutely and
without qualification, whether the disease will ter-
minate in death or in recovery.   He can never do
this.  Everything  connected with life is  subject
to contingencies w7hich no  human sagacity can
foresee.   In disease, as in health, we know not
what a day  may bring forth;  and all we can ever
do is to  calculate probabilities.   What I  mean to
say is, in the case before us, that these probabili-
ties can be very closely calculated.   The value of
the several  circumstances which influence and in-
dicate the degree of danger that attends  the dis-
ease, has  been  so  accurately determined, as to
enable us, in most  cases, to  measure this danger
with great  precision.  When the  disease, for in-
stance, occurs between the tenth and the thirtieth
years of life, coming on suddenly in a stout, robust 
■
26              AN INQUIRY INTO

person, previously in the enjoyment of good health;
if the inflammation is confined to the  middle and
lower portion of a single lung; if the respiration is
not more than thirty or  forty, and the pulse not
more than a hundred or a hundred and ten, in the
minute ;  if the expectoration is  reddish and tena-
cious, becoming  in a few  days yellowish  and
opake; if there is no extreme muscular debility  or
restlessness;  if, in  the course  of the  disease, the
urine, when treated by nitric acid, presents a pretty
abundant cloudy precipitate; and if the patient is
judiciously and promptly treated, the  danger of a
fatal termination is exceedingly small.  This ter-
mination  is possible,  but not probable.  On the
other hand, if the patient is past the fiftieth or six-
tieth year of life;  if his  constitution was delicate
at the time of attack, or if it had been  deteriorated
by the use of alcoholic drinks; if the pulse is more
than one hundred  and forty  in a minute;  if there
is great  rapidity  of respiration;  prostration  of
strength; a dark fluid expectoration of the color of
prune juice;  the urine remaining clear and show-
ing  no precipitate when  treated by nitric acid, it
is almost  certain that the disease will terminate in
death.   I do not say that it is absolutely impossi-
ble, under such circumstances, for a patient to re-
cover, but such, an  event is not at all probable.
Between  these extremes  there is, of course, every
conceivable  intermediate degree of danger, and
these intermediate degrees, like the extremes, may,
in most cases, be estimated with very satisfactory
precision and certainty. 
      THE DEGREE OF CERTAINTY IN MEDICINE.    27

  There is no other portion of the natural history
of diseases involved in so  much obscurity, as that
which relates to their causes.  Except in the case
of certain poisons, the efficient producing causes
of disease are  entirely unknown  to us.   One per-
son suffers and another  escapes, apparently under
the same circumstances, and subject to  the  same
influences, and we are  utterly unable to account
for the difference.  The most that we can do, is to
seek for, and to endeavor to appreciate, the circum-
stances and conditions  which seem  to  favor the
production of disease, and in  this way  to act as
its predisposing or exciting causes. In the instance
of the disease before us, the most important of these
are age, sex, season, exposure to cold, the previous
occurrence of the disease, and thatunknown agency
which we call epidemic influence.   Pneumonia
is sufficiently common  during early childhood;
from the age of six or seven, to puberty, it is much
less frequent; from fifteen  to twenty, its frequency
increases; it reaches its  maximum, from  twenty to
thirty;  and  it  continues to be of common occur-
rence through  all  the subsequent periods  of life.
In most parts of the civilized world the number of
cases  of pneumonia  occurring amongst males is
much greater than the number occurring amongst
females.  This is sufficiently accounted  for,  how-
ever, by the difference in  the occupations of the
two sexes.  Pneumonia occurs at all seasons of the
year, but it is much more common during the cold
than it is during the warm months; and so  on
of the other influences that I have mentioned. 
I
28              AN INQUIRY INTO

  The most important and interesting part of our
inquiry still  remains  to be  considered, and the
space that I have already occupied admonishes me
to desist from any further illustrations of the state
of our knowledge of the natural history of pneu-
monia.  It can hardly be necessary for me to do
so, although nothing would be easier, if the subject
before me required it.   I apprehend that some even
of my professional readers would be  surprised by
a full exposition of the extent and the positiveness
of this knowledge.   The different forms and va-
rieties of  the disease, its  various  complications,
and  especially its most important  and  numerous
relations  to  other diseases, might  all  of them
furnish us with instances  and evidences of  this
knowledge, not  less  striking than those I  have
already given.   But  I  have said enough, I think)
to convince the most  skeptical, and to satisfy the
most incredulous, that the  science of medicine, so
far at least as pneumonia is concerned, in no degree
deserves the charges of incompleteness and uncer-
tainty which have been laid at its door.
  The value  of medical science depends wholly
upon its connection with medical art.  It might, to
be sure, be cultivated,  as an interesting subject of
inquiry,  independent  of this connection;  but it
derives  most of its interest, and all of  its import-
ance, and practical utility, from its agency in the
prevention,  mitigation, and removal of disease.
These are its great  ends and  objects, and so far,
only, as it attains them, or ministers to them, can
it lay claim to our veneration  and regard,  as  a 
      THE DEGREE OF CERTAINTY IN MEDICINE.    29

blessing  and a benefit to our race.  It  happens,
however, that less confidence is felt in medicine, as
an art, than as a science.  It is precisely here, in
its chief end  and purpose, that it is said  to fail.
Physicians, it is admitted, may indeed understand
the seat and nature of disease, but it is denied that
they can, with any certainty or uniformity, con-
trol or cure it.   Practical medicine, it is asserted,
is altogether a hap-hazard affair of guess and con-
jecture, doing good  when this happens, more by
accident than according to any constant and fixed
principles, and as often doing harm as good.  It is
my purpose now to inquire honestly, and carefully,
into this matter.  I wish to show, and I intend to
do  so, according to  the  extent of my means  and
ability, the nature, the degree, and the certainty of
our power over disease.   For the purpose of illus-
tration, I shall continue to make use of the disease
which has already,  thus far, furnished me with
materials for my investigation.
  Considering the very wide differences in the forms
and character of pneumonia, there has been, for a
long time, a pretty general agreement amongst me-
dical men, in regard  to what has been considered as
the best method of treating it.   General blood-let-
ting,  during the early periods  of the disease, has
been  principally relied upon, by the immense ma-
jority of careful observers, and experienced practi-
tioners.   With only occasional and temporary ex-
ceptions, this has been the leading  and prominent
remedy.   So strong and so universal was the  con-
fidence in this remedy, that the feeling became very 
30
AN INQUIRY INTO
 general, that it was essential to the cure of the
 disease; or, at least, that  it could not be omitted,
 without the most imminent hazard to the patient.
 It was a very common, if not a general belief, not
 only that the chances of recovery were  almost in-
 definitely increased by the operation, but that the
 disease was very  much shortened in its duration,
 and in many cases wholly  and at once arrested.
 This conviction—the growth of centuries—was the
 gradual result of the aggregate, common, every-day
 experience of the profession, during this long pe-
 riod of time.  And it was never stronger, perhaps,
 or more firmly fixed in the general  medical mind,
 than at the period of the  publication, in 1828, of
 Louis's researches upon this subject,—the  effects
 of blood-letting in pneumonia.  This is a very re-
 markable work, and its conclusions have a  direct,
 and very important bearing, upon the inquiry in
 which I am engaged.   Louis's researches  con-
 stituted the commencement of a more rigorous and
 searching investigation than had hitherto been in-
 stituted, into the actual extent of our power  over
 disease.  The time for such an investigation  had
 now fully come.  It could  not  have been made
before  the  great discovery of Laennec had  pre-
 pared the way for  it, by giving us more accu-
rate and positive means of diagnosis than we had
hitherto possessed.  The general belief, of which  I
 have spoken, derived from the traditions of general
experience, did not  satisfy the positive and exact-
ing mind of Louis.  He said, in effect, if not in so
 many words,—I know very well that this belief is 
      THE DEGREE OF CERTAINTY IN MEDICINE.     31

almost universal; I know that it comes to us sanc-
tioned by the wisdom, and sustained by the  expe-
rience of ages;  but other beliefs, not less universal,
and not less firmly settled, have been proved at last
to be partly, or wholly false; there have been many,
and wide-spread  medical delusions, which  time,
and a  sufficiently thorough investigation, have  at
length dissipated; this  may  be one of the  same
class; at any rate, it is due to the cause of science,
and the interests  of humanity, that the subject
should be more closely studied than heretofore.   I
do not deny that the conviction is well founded,—
I deny nothing,—I only say that the evidences of
its truth do not exist, or, at  least, that  they have
not been furnished to us,—I cannot find them.
   Between the years  1821  and 1827, Louis stu-
died carefully,  and from  day to day, at La Cha-
rite,  the effects of blood-letting in fifty cases  of
pneumonia, terminating favorably, and in twenty-
eight  cases which terminated in death.  The pa-
tients were bled from one to four times, according
to the indications in each case; from ten to fifteen
ounces of  blood being taken at each  operation.
Of the fifty cases terminating in  health, twenty-
three were  bled, for the first time, within the first
four days from the commencement of the disease,
and the average duration of the disease in  these
cases was seventeen days; twenty-seven were bled
for the first time, between the fifth  and the ninth
days, inclusive,  and the average duration of the dis-
ease in these cases, was twenty days. Every possible
precaution was taken, that the two groups of cases, 
32
AN INQUIRY INTO
thus compared with each other, should be essen-
tially alike in all the circumstances that could, in
any way, affect the danger of the disease.   Louis
studied, further, the effects  of the  same  remedy
upon the  leading  symptoms of  pneumonia.   He
found that the pain in the side was never  wholly,
and  at once, removed by an early blood-letting;
but, that on the contrary, it was generally more se-
vere, for twelve or  twenty-four hours after the first
bleeding, if this was practiced early in the disease.
He found, however, that the average duration of the
pain in the first group of cases, was six days, and a
little over eight days in the second group. He found
that most of the other symptoms were moderately
influenced  by the  bleedings.  Between the years
1830 and 1833, Louis studied in the same manner,
at La Pitie, the effects of blood-letting in twenty-
nine cases of pneumonia, four of which terminated
fatally. Of the twenty-five cases terminating favor-
ably, thirteen were bled  between the second and
fourth days of the  disease, inclusive; and the ave-
rage duration of these cases was fifteen days and
a-half; the other twelve cases were bled from the
fifth  to  the fourteenth day, inclusive, and  their
average duration  was  eighteen days  and a-quar-
ter.  No one of these cases was bled on the first day
of the disease.  The first bleedings were  a little
more copious than  in the cases at La Charite.   The
effects of the remedy upon the individual symp-
toms did not differ from those in the latter cases.
   So far as this limited investigation  could  settle
the question, Louis considered himself justified in 
      THE DEGREE OF CERTAINTY IN MEDICINE.     33

coming to this  conclusion,—that blood-letting has
a favorable effect  upon the  march of pneumonia;
that it abridges its duration;  but that this effect is
much less than had generally been  supposed, pa-
tients who are bled during the  first four days of
the disease, all  other things being equal, recovering
four  or five days sooner than those who are bled
later.   And as far as  this particular investigation
is concerned, the conclusion is perfectly justifiable
and legitimate.   It  results with a slight qualifica-
tion, necessarily and inevitably, from the facts; and
Louis never pretended to carry the conclusion be-
yond this.  He says, expressly, that these facts are
neither  sufficiently numerous, nor sufficiently va-
rious, finally to settle the question  at issue;  and
that he publishes them principally, for the purpose
of calling anew the attention of observers  to the
subject.  It is important to bear in mind that these
investigations  show directly, not so  much the ab-
solute effects of blood-letting, as the difference in
its effects when performed early, or late, in the dis-
ease.   His conclusions,  so far as his own facts are
concerned, would havo been more  truly  stated, if
he had confined  it to early, compared with  late,
blood-letting.*

  * There is one other important conclusion of Louis's, which is not
kept strictly within the limits of his facts. It results from his investi-
gations, he says, that pneumonia is not arrested by early blood-letting.
It would have been  more exact to have said, that, according to these
investigations, pneumonia is not arrested by bleedings, practiced after
the first day of the disease.  I do not mean to say, that this conclusion
is a false  one; I say, merely, that it does not follow directly, and ne-
cessarily, from the facts from which  it is derived.  The somewhat
     3 
34
AN INQUIRY INTO
   In 1836,  Dr. James Jackson, of Boston,  pub-
lished a detailed analysis of thirty-four cases of
pneumonia, received into the Massachusetts Gene-
ral Hospital between the years 1825 and 1835, for
the purpose of  showing, according to the accurate
and positive method adopted by Louis, the effects
of treatment upon the disease.   Without following
him through all the  steps of  his  analysis,  it is
enough for me to say, that his conclusions in regard
to blood-letting correspond essentially with those
of  Louis,  with  some  difference in  favor  of the
former.  The average duration  of the disease in
those who were bled for the first time on or before
the fourth day, was about twelve days; the average
duration in  those bled  after the fourth day, was
thirteen  and a  quarter; and in  five  cases  which
were not bled,  except locally in one, the average
duration was fourteen days and a half, nearly.  The
latter cases wrere also the mildest. I will only add,
that Dr. Jackson is disposed to attribute the shorter
duration of  his cases,  when compared with those
of Louis, in  a considerable degree at least, to the
warmer temperature of the rooms  in which  the)7
were placed, and to the better general care  which
they received.   Dr. Jackson also found the  effects
of early blood-letting upon the pulse, the pain, and

moderate difference between the effects of early, and late blood-let-
ting, might justify the probable conclusion, that blood-letting at the very
onset of the disease, would still fail to arrest it; but this question
could be positively settled, only by this particular application  of the
remedy. The effects of blood-letting might be very different  within
the first few hours, and after the first day of the disease. 
      THE DEGREE OF CERTAINTY IN MEDICINE.    35

the character of the sputa, somewhat more marked
and immediate than Louis.
   In  order  to  know exactly and  positively the
effects of remedies, we ought to be able to compare
groups  of cases  treated by  them in all their vari-
eties and combinations, with corresponding groups
of cases left to themselves, or treated without these
remedies.   This is obvious.   We  cannot know
certainly what are the effects of our  treatment,
unless we have some reasonable and positive assu-
rance as to what would  have been the course and
termination of the disease if the treatment had been
omitted.  In the  case of pneumonia, as well as in
that of  most other grave diseases, this knowledge
is in a good degree wanting; at least it is scanty
and incomplete.  The conviction is so general and
so strong that  this disease  may be  controlled by
remedies, that it  is hardly ever left  to itself;  and
certainly no physician, in the present state of our
knowledge,  would be  justified, merely for the pur-
pose of elucidating and determining  this question,
in adopting  such a course.   We  have  no right to
sacrifice the interests of humanity to  those of
science.   But the positive and conclusive evidence
derived  from this comparison is not altogether
wanting.  It could hardly have escaped observa-
tion, that pneumonia might terminate in recovery,
quite independent of any aid derived from medical
art.  Cases  must  always occasionally, and not very
unfrequently have been met with, in which from
circumstances of one kind or another,—the caprice
or necessities of the patient, or the  neglect of the 
36
AN INQUIRY INTO
physician,—no active remedies were made use of,
and which  still ended in health.   Besides this, the
use of the leading remedies, although very general,
has never been absolutely universal.   One practi-
tioner has treated his patients without blood-letting,
another without antimony, another  without mer-
curials,  another without blisters, and still, with all
these omissions, patients have continued to recover.
This  must have rendered it  sufficiently obvious
at least, that no one  of these remedies was abso-
lutely necessary to  the  cure of the  disease.   But
we have evidence upon this subject still more  pre-
cise and definite, which it is important that I should
give.  I have already referred to five of Dr. Jack-
son's  cases in which general blood-letting  was
omitted, and which terminated in health, but in
which the average duration of the disease was con-
siderably longer than  in graver cases where  blood-
letting  was practiced.   During  the  year  1840,
Grisolle treated eleven patients attacked with pneu-
monia,  without using any  active remedies.   The
patients were  mostly young, one  only having
reached the age of fifty-six years; and all the cases
were sufficiently mild to justify M. Grisolle, as he
thought, in leaving  them without any active treat-
ment.   They were  confined to bed, on a light diet,
had some pectoral drinks, and, in a few instances,
a simple laxative; like castor-oil.  In nine cases, the
inflammation had reached its second  stage when
the patients  entered  the hospital; in  two,  it was
still  in  its  first stage, and did not  pass  into the
second.   The cases  all terminated favorably, but it 
THE DEGREE OF CERTAINTY IN MEDICINE.    37
is very important to remark, that, considering the
limited extent of the inflammation, and the general
mildness  of their  character, the prominent  symp-
toms of the disease persisted for an unusually long
period of time.  The brick-dust, tenacious expec-
toration preserved its character, on an average, till
the ninth and nearly till the tenth day of the dis-
ease; the pain in the  side did not  wholly cease
in any case before the seventh day, and in several
it continued till  the twentieth, twenty-fifth, and
twenty-seventh, its  mean  duration  being fifteen
days;  and in  some of these  cases, it was only re-
moved, at last, by scarified cups or blisters.  The
general fever, which was in no case high, usually
continued till towards the tenth  day; while  the
physical signs did not begin to diminish before the
close of the second week, four or five days after
the cessation of the fever, and they did  not wholly
cease, until from the twenty-second to the thirtieth
day.   Fixing the time of convalescence, at one or
two days after the  subsidence of the fever, this
occurred  from the eleventh to the twelfth day.
   I shall now compare with  the foregoing results,
those in a corresponding group of thirteen cases,
actively treated.  As in the first group, the patients
were young, and the inflammation not extensive,
so that they might,  safely enough, have been  left
to themselves.  In  nine cases, the inflammation
had reached its second stage; in  four,  it was still
in its first, when the  treatment was  commenced.
The patients were bled, generally or locally, once
or  twice, from the  first to  the sixth day  of  the 
38
AN INQUIRY INTO
disease, on an average, near the fourth day.   The
sputa lost their pneumonic character, on the sixth
day of the disease, about forty-eight hours after the
blood-letting; the pain in the side, which was very
acute in several cases, was invariably mitigated by
the general or the local bleeding, and  ceased en-
tirely from the second to the twelfth day, the ave-
rage day being the eighth;  the  general fever had
wholly subsided at the end  of the first week, and
twenty-four hours later, convalescence was fully
established; finally, the physical signs  began to
diminish with the cessation of the fever, that is, on
the seventh day; and in ten patients, whose chests
were  carefully examined at the time of their dis-
charge, this average period  being the twelfth day,
the lungs  had entirely  recovered their  permea-
bility.
   M. Grisolle has studied and analyzed, according
to this same  rigorous method  of Louis, and  his
exact school, still other groups of cases, under  dif-
ferent conditions and circumstances.  The results
of this study and analysis, I shall very briefly
state.  The first group  consisted of fifty cases, in
which, when received into the hospital, the inflam-
mation was still entirely in its first stage.  Sixteen
of the patients were females; more than four-fifths
had at least an average  strength and vigor of con-
stitution, the others were thin, delicate, and wTith
systems more or less deteriorated; the ages of the
patients varied from sixteen to  seventy-two years,
the average being forty  years.  The treatment was
commenced from  the first to the  tenth day of the 
THE DEGREE OF CERTAINTY IN MEDICINE.    39
disease;  in a majority of cases between the third
and the fourth.   In fourteen patients, the disease
was light; in  the remaining thirty-six, the symp-
toms were sufficiently grave to render the issue of
the cases more or less doubtful.  All the patients
were bled from one to five times, according to the
indications, and  circumstances of each particular
case,—the gravity and  period  of the  disease, the
age and constitution of the patient,  and so on.
The average quantity of blood taken was not far
from three pints.  Five of the  cases terminated
fatally.   In more than two-thirds of the cases, the
inflammation  passed from the first to the  second
stage;  in the others, this did not happen.  This
partial arrest, in the  customary march of  the in-
flammation, could not be attributed to any greater
activity  of treatment, since  these  patients were
bled much less freely than the others; it depended
apparently upon the lightness of the disease.  The
mean period  of  convalescence  was  towards  the
tenth day.
  The  second group  consisted  of  one hundred
and eighty-two cases, in which the inflammation,
in whole or in  part,  had already reached its se-
cond stage, when the treatment was  commenced.
Thirty-nine of the  patients were females;  nearly
three quarters had constitutions of average vigor;
all the rest were delicate and feeble.   The ages of
the patients varied from sixteen  to seventy-seven
years, the average being thirty-five.   The disease
was more or less grave in all the cases; in twelve,
both lungs  were involved.   The treatment was 
40
AN INQUIRY INTO
 commenced from the first to the eighth day of the
 disease, the average period being four days and a
 quarter from the beginning of the  disease.  The
 number of bleedings varied from one to six; and the
 quantity of blood taken, from eight ounces to four
 quarts. Thirty-two of the cases terminated fatally
 more  than one-sixth.   Of the one hundred and
 fifty patients who were cured, blood-letting was the
 only  active remedy in sixty-nine; in the other
 eighty-one, antimonials wrere made use of.   These
 cases will be more particularly spoken of by and
 by.   The larger mortality in this group, than  in
 the preceding one, is sufficiently accounted for by
 the more advanced stage of the disease, and by the
 somewhat later period  when  the  treatment was
 commenced.  Of the one  hundred and one cases,
 treated principally by blood-letting, and terminat-
 ing in recovery, in one-seventh  where the  inflam-
 mation was  still in  its first stage when the treat-
 ment was begun,  and in one-twelfth,  where the
 inflammation had  reached its  second  stage, the
 first bleeding was  immediately followed by a de-
 cided amelioration of some of the rational  symp-
 toms; this amelioration being accompanied, in only
 one-third of the cases, with any appreciable change
 in the physical  signs.  This prompt and  decided
 effect  usually occurred  under the two following
 circumstances, to wit:—first, when the  inflamma-
 tion was  limited to a small  portion of  the  lungs,
 and the general symptoms were in no  degree vio-
lent or grave: second, when  the blood-letting was
practiced at a somewhat advanced period of the 
      THE DEGREE OF CERTAINTY IN MEDICINE.     41

disease, when probably in its natural progress, it
was tending to diminish.  When blood-letting was
several times repeated in the same case, each ope-
ration was generally followed by  a more or less
marked improvement, in one or more of the symp-
toms.  In no case was the disease wholly arrested.
The pain in the side wholly disappeared immedi-
ately, or soon after, the  first blood-letting, in about
one-twentieth only of the cases; in nine-tenths, it
was more or less diminished, and it usually yielded
more rapidly to local, than to general bleeding.   Its
mean duration was seven days.  The influence of
the treatment upon the  character of the  sputa
was less marked, and the same thing is true  of the
physical signs.   In two-thirds of the cases, the
first blood-letting was  followed by a diminution,
more or less considerable, of the  rapidity of the
pulse.   When the first  bleeding was practiced in
the course of the first four days of the disease, the
pulse began to become slower between the fifth and
the sixth day, and  fell  to its natural  standard  by
the eleventh; when, on the contrary, the first bleed-
ing was not practiced till after the  fourth day, the
pulse did not begin to diminish in frequency till
towards the ninth day, and did not reach its natu-
ral standard till near the thirteenth.
  I have now done with the subject of blood-let-
ting in the  treatment of pneumonia; and what are
the results of the investigation through which we
have gone?  Is it proved, or is it not proved, that
this remedy has a favorable influence over the dis-
ease ?  Most certainly there can be but one answer 
42
AN INQUIRY INTO
to these  questions.   The accredited and  settled
belief which has  prevailed ever since the age of
Hippocrates in the efficacy of blood-letting in the
treatment of pneumonia, is not an error and  a delu-
sion ;  it has its foundation  in nature and in truth.
And this efficacy is no longer a matter of belief
merely, resting on  the basis, broad  enough  cer-
tainly, but not always to  be trusted, of what is
called general experience.   It is sustained by posi-
tive proof,—by all  the proof, and  the only proof,
of which, in the nature of things, it is susceptible.
It has the sanction of clear, intelligible, philoso-
phical demonstration.  It can neither  be  denied
nor doubted, except as the  reality of  the material
universe, or the truth  of the Newtonian system,
may be doubted  or denied by some  eccentric or
crotchety dreamer, who cannot or will not see phe-
nomena and their relations as  they show themselves
to the eyes of all other men.  Louis has  demon-
strated that the circumstance of a few days' differ-
ence in the time of practicing blood-letting, makes
not merely a trifling and unimportant, but a very
considerable difference in the duration of the dis-
ease, and a corresponding difference in the duration
of its  leading symptoms.    Grisolle  has  demon-
strated, in the same manner,  that mild and slight
cases of  the disease, although they would recover
without any active  remedies, have all their promi-
nent symptoms very greatly  mitigated in severity
and shortened in  duration by blood-letting.  These
cases do not  absolutely prove that the remedy
saves life, because in these cases life is saved  with- 
      THE DEGREE OF CERTAINTY IN MEDICINE.    43

ou,t it; but they do prove the favorable action and
effect of the remedy,—all that they are capable of
proving, in the nature of the case.  I ought to add
here, that these positive results of Louis' and Gri-
solle's researches stand entirely uncontradicted by
any adequate counter testimony.   They are sup-
ported and corroborated on every  hand — com-
passed about with a great cloud of witnesses—but
there is no  authentic and  reliable observation
which throws  upon them the shadow of doubt,
The cases of Dr. Fleischmann, treated on the ho-
moeopathic system, and  cited by Dr. Forbes, are
utterly without value in their bearing on this ques-
tion.  No  one  circumstance affecting  the danger
of the disease is given, so that the most essential ele-
ments of the problem which they are made use of to
solve, are wholly omitted.  Besides this, the  table
of Dr. Fleischmann contains other  internal evi-
dence that no reliance is to be placed upon it.  One
hundred and five cases of peritonitis  are given,
with only  five deaths.  What does this  mean ?
Does anybody  believe that this number of cases
of this disease occurred  in a small hospital in the
course of eight years, and that only five of them
terminated fatally ?
   I am  not writing an essay on the treatment of
pneumonia by  blood-letting,  but I may very pro-
perly close these remarks by saying that  the best
methods of using this remedy, and the various cir-
cumstances which require  modifications in its ap-
plication,  or which may render it improper and
unsafe; such as the age, sex, constitution, previous 
44
AN INQUIRY INTO
habits, and actual condition of the patient, the stage
or period of the inflammation, the form or variety
of the disease, the existing medical constitution, or
epidemic tendency, and so on, have all been very
well ascertained and determined.
  But besides blood-letting, there is another remedy
which has long enjoyed, and which still continues
to enjoy, a  high reputation  in  the cure of pneu-
monia.   This  is  the  tartrate  of antimony  and
potassa;  and a careful examination of its  effects
upon the disease, such  as I  have  just made in re-
gard to blood-letting, will  throw a new and clear
light upon the subject before us, and complete the
particular and  detailed  illustration which I have
been  following out.   It  is  not necessary  that  I
should give the therapeutical history of this article.
I will  merely say, that a  new  and  extraordinary
celebrity was given to it, some fifty years ago, by
the free and bold manner in which it was adminis-
tered, and by the wonderful  properties which were
attributed to it, by Rasori.  Laennec introduced
the Rasorian  method  into  France in 1817, and
since that time the use of antimony in the treat-
ment of pneumonia  has been becoming more and
more  general,  and  is  now  nearly  universal.
Amongst the earliest and most positive statements
of its efficacy, founded upon exact numerical data,
were those of Louis  and Trousseau; but my own
purpose will be better and more fully answered by
a summary of the very careful, extensive, and most
conclusive observations of Grisolle.
   M.  Grisolle  arranges the cases, in which  he 
      THE DEGREE OF CERTAINTY IN MEDICINE.    45

studied the action of antimony, in three groups or
series.   The first of these  consisted of forty-four
cases, observed at the Hotel Dieu, during the years
1839  and  1840, in  which  no  active  remedy was
made use of excepting antimony.  Thirty-six of the
patients  were males, and  eight females.   Their
ages varied from fifteen to seventy-one years, the ave-
rage being thirty-seven. Nine had vigorous constitu-
tions ; fifteen had constitutions of medium strength ;
and the remainder, nearly one-half,  were thin and
delicate.    In  thirty-five cases, the inflammation
had  entirely passed into the  second  stage, when
the special treatment was commenced; in the other
nine, the inflammation was, at least for  the most
part, still in its first stage.  The disease was gene-
rally grave;. in no case was it mild; in more than
three-quarters of the cases  at least the half of  one
lung was involved.   In all  the patients the disease
was sufficiently  severe,  at  the  commencement of
the treatment, to render its issue more or less doubt-
ful.  The treatment was begun from the second to
the ninth day  of the disease, the mean  period being
the fourth  day.  Six grains of emetic tartar was
the  quantity  usually given, in the  twenty-four
hours, in five  ounces of a sweetened vegetable in-
fusion.   Sometimes  only four grains  were given,
and  the  quantity was never carried  higher than
twelve.   If the  effects of  the remedy on the  sto-
mach and bowels during the first day were violent,
on the  subsequent days,  a small quantity of an
opiated syrup  was given at short intervals.  This
treatment was kept up  from one to four days, the 
46
AN INQUIRY INTO
average period being about three and a-half days.
Most of the patients took, in the  whole,  about
twenty grains : in  no instance  did the quantity
exceed sixty grains.   Vomiting and purging were
present in every case, at least for the first day or
two, the latter generally predominating.  Of thirty-
six patients to whom the antimony was given for
several days, there were seventeen in whom the
vomiting and purging wholly ceased after the third
or  the fourth  day.  Of the  forty-four cases, six
terminated  fatally, a little  less than one-seventh.
The mean age of these patients was over fifty years,
and the treatment  wTas  not commenced till  after
the fifth day.   The following were the apparent
effects of the remedy upon the principal symptoms
of the disease.  The pain in the side, even when
it was excessively severe and acute, was generally
greatly relieved, or altogether removed.  Of thirty-
four patients in whom the pain was present when
the treatment was commenced, twenty-three  were
considerably relieved from the first day ; in five the
pain, which was excessively acute, was  entirely re-
moved.  In five other cases, the pain did not begin
to diminish till after the second  day; in three it
became more violent, and persisted till local bleed-
ing was resorted to.  One of the most constant and
striking effects of  the remedy  consisted  in  the
diminution in the force and frequency of the pulse.
In twenty-seven patients, of the thirty-eight who re-
covered, the pulse  on the second day had diminished
to the extent of from ten to forty in the minute;
in six the  diminution did  not take place  till the 
      THE DEGREE OF CERTAINTY IN MEDICINE.    47

third  day;  in  four  not till  the fourth;  and in
one the  rapidity of  the pulse continued during a
considerable part of the period of convalescence.
The diminution in the frequency of the respirations
was less striking and uniform.  As a general rule,
the improvement was most marked in cases where
the breathing was most accelerated.   The viscid
brick-dust expectoration lost its pneumonic charac-
ter and became yellowish or colorless, in most cases
within from one to two or three days.  With a single
exception, in which the physical signs  continued to
increase for four days after the use of the antimony
was begun, these signs either remained stationary,
or began  to diminish, from the first day.   Thus, in
eighteen cases,  signs of resolution were manifest at
the close of the first  day; in eleven, at the close of
the second; in two, at the close of the third; and in
five, at the end of the fourth.  Still, the  stetho-
scopic phenomena were never entirely removed in
this short period of time; some traces of them re-
mained, in most cases, at the time when the patients
left the hospital.  The heat of the skin,  the headache,
the thirst, and the general restlessness diminished or
ceased with the same promptitude.  Another very
striking and very constant result of this treatment
was seen in the rapidity of convalescence, and in
the small impairment of the muscular strength.
The mean duration  of the disease was ten days.
In  more  than half  of the patients who  died, the
use of the antimony was followed by  a temporary
mitigation in the severity of the disease.
  The second  group consisted of eighty cases in 
48              AN INQUIRY INTO
 which the administration of antimonials was pre-
 ceded by one or more bleedings, general and local,
 these not having produced any very decided effects
 upon the progress or the principal symptoms of the
 disease.  The bleeding in all  these cases might
 have been repeated;  it wTas not contra-indicated by
 the state of the patient;  but instead of this, anti-
 mony was resorted to.  The ages of the patients
 varied from sixteen  to seventy years, the average
 being thirty-five  and a-half.   The  disease  was
 grave in all; in five-sixths, the inflammation occu-
 pied at least a-half of one  lung ; in eight cases, it
 extended to both ; in the  remaining one-sixth, the
 disease,  though less severe, could not be regarded
 as  mild.  In every  case, the inflammation  had
 reached, if not in whole at least in great part, its
 second stage, when the antimonial treatment was
 commenced, which was generally from the sixth
 to the seventh day of the disease.  Seventy of these
 patients  recovered, and  ten  died.    Of the first,
 the pulse fell to the extent of from ten to thirty beats
 in the minute,  immediately  after the first daily po-
 tion, in thirty-seven ;  in only five, was the diminu-
 tion deferred till after the  third  daily potion.  In
 more than  half the cases,  the  second day of the
 treatment brought with it  a marked amelioration
 of the heat of the skin, the pain in the side, the color
of the sputa, the difficulty of breathing, and the phy-
sical signs.   A very decided amendment took place
in two-thirds of the cases during the first two days
of the treatment.   The remaining details of these
cases it is not necessary to give. 
THE DEGREE OF CERTAINTY IN MEDICINE.
   Finally, in a third series were  arranged thirty
 cases  which  had been abundantly bled,  and in
 which the disease had, notwithstanding, continued
 to make constant progress; the state of the pulse
 and the general condition of the patients were such
 as to render any further loss of blood entirely out
 of the question; the danger in every case was ex-
 treme, and antimonials  were given as the only and
 last resort.  Half the cases were desperate, when
 this treatment was commenced.   Eighteen of them
 terminated fatally, and in more than half of these,
 death  took place within two days after the  com-
 mencement of the antimonial treatment.  In nine
 cases,  where  life was in imminent peril, there was
 so decided an amendment after the first, second, or
 third daily potion, that the patients might be looked
 upon as almost out of danger.
  I have now given a sufficient number and variety
 of facts showing the effects of certain remedies
 upon a given  disease, to  answer the purposes of
 illustration and of proof which I had in view.   I
 could easily add to these facts, if it were at all ne-
 cessary or important to do so.   I will merely say
 that in making a selection, I have chosen not those
 that were most favorable to the powers of  art, but
 those that were best calculated, from the compe-
 tency of their observers, and from the manner  in
 which  they were made, to  exhibit the actual extent
 and degree of these powers, whether small or great.
An  important  part of my work  still remains,—to
sum up the testimony which has been given, to
measure its  strength,  and to estimate its value.
    4 
50
AN INQUIRY INTO
 Let us endeavor to see what is the precise charac-
 ter of the evidence, contained in the foregoing state-
 ments, that we  can  control and  cure pneumonia.
 Let us analyze, as far as we can, this evidence, and
 reduce it to its elements, in order to  determine its
 nature, and to fix  its degree of positiveness.
  In the first place, it is entirely certain, that many
 cases of pneumonia terminate naturally and  spon-
 taneously, so to speak, in health, quite independent
 of any active medical treatment.  This  is not a
 matter  of inference  merely, or probability, but of
 positive certainty, ascertained by ample and  con-
 clusive observation.   I need here only refer to the
 cases reported  by M. Grisolle.   How many cases
 would so terminate, it is of course quite impossible
 to say.  The proportion is  probably large; it  is
 certainly very considerable.  For instance, every
 thing that we know of the disease leads to the con-
 clusion, that nearly all cases of moderate or average
 severity, occurring from the eighth or tenth, to the
twenty-fifth or  thirtieth year of life, in persons of
sound constitutions,  and  up to the time of attack
in good health, would, under the  ordinary precau-
tions of rest, regimen, and so on, terminate spon-
taneously in recovery.  Such, at least, is the gene-
ral tendency, and the general result in these cases.
This conclusion rests upon the  fact, that many
such cases  have been known to recover without
any  active treatment; and that under various, and
in some  degree, opposite modes of treatment, the
mortality in this class of patients,  is almost always
very small. 
       THE DEGREE OF CERTAINTY IN MEDICINE.     51

   In the second place, it is as certain, that some
 cases of the disease will terminate fatally, notwith-
 standing any assistance wrhich art may furnish, and
 in defiance of this assistance.  Under all modes of
 treatment,—positive or negative—heroic or expect-
 ant—that have  ever  been adopted, however skill-
 fully and judiciously applied, numerous cases of
 the disease have always  terminated, and still con-
 tinue to terminate, in death.  In the  actual state
 of our knowledge, there are many cases over which
 art has little or no  control, at least not enough to
 prevent their fatal issue.   And here it is important
 to observe,  that everything in  the natural history
 of pneumonia, and in the analogies derived from
 other diseases, leads  to the conclusion, that these
 cases are, as Sir Gilbert Blane said of the  worst
 forms  of yellow-fever, u determinedly fatal,"— ter-
 minating not contingently and accidentally,  or
 through want of knowledge and skill, but necessa-
 rily, and inevitably, in death.  There is good rea
 son for believing, not that they are  fatal, through
 our ignorance,—merely because we have not yet
 discovered  the means of  curing them,—but that
 they are fatal, in the nature of things, and by their
 own constitution.  There is every reason for be-
 lieving, not that we have failed to find the means
 of curing them, but that there are no such means.
 The conditions under which these cases occur, and
the circumstances which give them their character
of fatality, are for the most part very well known.
For instance, double pneumonia, or extensive sin-
gle  pneumonia, occurring in a person over seventy 
52
AN INQUIRY INTO
years old, with a constitution  already deteriorated
by the habitual use of alcoholic drinks, will almost
certainly prove fatal.   What may be the number
and proportion of this class of cases, it is of course
impossible to say, except in  a very general  and
comparative way.  This proportion cannot be large;
it is  probably very small; it is  certainly much
smaller than that of the first, and opposite class.
  Finally, there is  a third class of cases, occupying
the ground between the two foregoing classes, and
not tending necessarily either in one direction or the
other, not terminating naturally in recovery, nor in-
evitably in death.   It may be impossible to predicate
this of any given  individual case  of the disease;
indeed, the very constitution of this class of cases
renders it so.  Their termination is contingent; it
depends upon circumstances; and we cannot know
absolutely, that any given case of this  class, ter-
minating  in death,  would,  under  any circum-
stances, have terminated otherwise.  There are no
means of knowing  this; and let not medical science
be blamed, for what is beyond the  reach  of human
faculties.  But this does not affect the truth of the
general assertion.   Our inability, growing  out of
the nature of things, to assert absolutely of any
given single case, that it belongs  to this class, in
no way prevents us from demonstrating  the exist-
ence of the class itself.   Of one hundred children
born on the same day in England  and Wales, it is
impossible to say  of any one of them, that  it will
die in the course  of the first year;  but  this does
not hinder us from knowing that such will be the 
       THE DEGREE OF CERTAINTY IN MEDICINE.    53

 case with about fifteen of the hundred.  If, of a
 hundred patients, with pneumonia, subjected to the
 influence  of certain circumstances, fifty die; and
 if of another  hundred  under similar conditions,
 subjected  to the  influence of different  circum-
 stances, only twenty-five die, and if this result is
 repeated  again and again,  although it may be im-
 possible to say which  twenty-five  patients have
 been saved, it is none  the less  certain that this
 number have been saved.   There need be no more
 doubt, then, as to the existence of this third class
 of cases, than  there is  as  to that of the first two
 classes, provided there  is  sufficient, and  suitable
 evidence  of the fact. And this evidence is entirely
 conclusive.  Nobody can study the statements that
 have already been made, in the course of this in-
 quiry, and have the slightest doubt upon the sub-
 ject ; I suppose no one has any doubt about it.  It is
 obvious, that the more positive and absolute proofs,
 to be derived from a comparison of  the  results, in
 death or recovery, of large numbers of this class
 of cases,—half actively treated,  and half left  to
 themselves—is, to  a great degree,  unattainable.
 These cases are of course grave cases; they threaten
 life; they  are attended with considerable, or with
 great danger; and  they are not left to themselves
 in sufficient numbers, to furnish  us  with any con-
 siderable amount of this species of  proof.   But it
 is impossible to doubt that a remedy,  or a method of
 treatment, possessing great and unequivocal control
 over a disease, almost invariably, when properly and
promptly applied, greatly mitigating its severity, and 
54
AN INQUIRY INTO
 abridging its  duration, must often  determine the
 issue of the disease, and save the life of the patient.
 It would be  utterly illogical  and preposterous to
 doubt this, or to believe otherwise. In the particu-
 lar instance before us,  what the number and  pro-
 portion of this class of cases may be, it  is again
 impossible to  say.  I  will remark, however, that
 the natural history of the disease justifies the con-
 clusion, that these cases are not rare and excep-
 tional, but that they are sufficiently numerous, and
 of common occurrence.
   When  the  favorable circumstances, which  de-
 termine the degree of danger from the disease, age,
 constitution, extent of inflammation,  and so on,—
 preponderate, we  shall have the first category of
 cases,—tending towards spontaneous recovery, and
 in most cases reaching it, without the aid of art,—
 at least without the aid of what are  called active
 remedies:  when  the  unfavorable circumstances
 preponderate, we shall have the second category of
 cases, tending  towards a  fatal  termination,  and
 reaching it, in spite of the efforts and aid of art:
 finally, when  these favorable and unfavorable  cir-
 cumstances are more or  less equally combined,
 we shall have the  third category of cases, not tend-
 ing spontaneously towards recovery, and not  re-
 sulting inevitably  in death *In these cases, art, ju-
 diciously applied, saves  the life of the  patient; the
 issue of the cases—in death or in  recovery—is de-
pendent upon the treatment of the disease. 4
   So far  as  the two  principal objects of our in-
 quiry are  concerned, we may embody the results 
       THE DEGREE OF CERTAINTY IN MEDICINE.     55

 of the preceding investigation in the two following
 brief propositions:—
  First:—The science of medicine, so far as  pneu-
 monia is concerned—although, like  other natural
 sciences, still unfinished and  progressive—is, to a
 very satisfactory extent, settled  and  positive;  the
 principal phenomena and relations of this disease,
 have been well and accurately ascertained; its na-
 tural history is, in a good degree, and to a  consi-
 derable extent, complete.
   Second:—Medical art, so far as pneumonia is
 concerned—although not endowed  with absolute
 and unqualified  power—is still  of great and  un-
 questionable utility.  Through the agency, princi-
 pally, of blood-letting and antimonials, as its most
 active means, it lessens  the  severity  of the  dis
 ease, shortens its duration, and in many instances
 prevents its termination in death.
   Such, then, I believe to be a fair and true state-
 ment of  the  nature, and the extent of the power
 of art, over this form of disease.   It  may seem to
 some, that this powTer is circumscribed within very
 narrow limits,—that it  is so "cabirid, cribUd, con-
fined," so qualified and  contingent, as to be of little
 worth.   I do not think so.   Its power seems  to me
 to be very great, and its value beyond all estimate.
 Such is  the constitution of nature, that some cases
 of the disease are beyond its  reach;  others would
 struggle through their successive stages, without
 its  formal  and active  aid;  but  the  hard rigor of
 the former is often softened by its ministry;  the
 latter are almost always benefitted by its interfer- 
56
AN INQUIRY INTO
ence; while in many other cases, it determines the
momentous issue of life or of death, and turns the
trembling balance in the sufferer's favor.
  As I have  already said, I am not laying down
rules for the  treatment of pneumonia; but before
leaving this subject, it may be proper for me to re-
mark, for the information of my non-professional
readers, that in addition  to  the  heroic remedies
which are chiefly relied upon, there are numerous
other means  of secondary and subordinate value,
but the utility  and importance of which  are not
less certain than those of the former.
  It does not enter into my plan, to institute any
comparison between the generally established mode
of treating pneumonia, and other methods,—those
for instance of what are called vegetable practition-
ers, and of the  homoeopathists.  It is  sufficient to
say, that neither of these classes of physicians  have
furnished any adequate evidence of the superiority,
or the efficacy, of their respective methods.  They
allege, indeed, and one class with as much confi-
dence as the other, and on precisely similar grounds,
that  their patients recover, and that they recover
more rapidly, and in larger proportion, than those
treated in what has been  called the regular way.
But they have furnished no proof, whatever, of the
truth of the latter part of this assertion;  there is
no such proof anywhere to be found.   Under this
state of the case, until they exhibit some evidence
of the efficacy of their remedies, such as scientific
medicine has exhibited of its, until they can point
us to investigations corresponding at least  in some 
      THE DEGREE OF CERTAINTY IN MEDICINE.     57

feeble degree, to those which I have cited, it is dif-
ficult to see by what rules of logic, by what prin-
ciples of philosophy, or by what code of morals,
we can be asked to believe in their doctrines, or to
adopt their practice.
   I have already intimated the possibility, at least,
of the suspicion being entertained, that I may have
acted the part of an unfair and interested partisan,
in the choice I have made of a subject for my prin-
cipal illustrations, and it is easy to see that this sus-
picion may have been strengthened by  the  illus-
trations themselves.   My  more skeptical readers
will be very likely to say—"To be sure, we are
willing to admit, that, so far as pneumonia is con-
cerned, you have made out a very strong case; it
seems to be clear enough that your science is not
wholly in the dark, and that your remedies are not
entirely destitute of  certainty and power; indeed,
we may say, that with  our present impressions
upon this subject, if it should so fall out that our
own lungs were to be invaded  by this inflamma-
tion, we  should not feel  altogether at ease, and
quite sure  of the safety  of our position, in any
other hands than  such as you have  made us ac-
quainted with.  But this may well be so;  you have
chosen your own  subject, and treated it in  your
own way.   Pneumonia is only one amongst many
diseases; how is it  with  the  rest of the Protean
host?  Do  the doctrines you have laid  down, in
regard to that single  disease, hold good in regard
to the rest?   Does medical science know them, and
can  medical art control and  cure  them, as they 
58
AN INQUIRY INTO
know and cure pneumonia?   Are the high claims
you have set up in this particular instance in any
degree, or to any considerable extent, applicable to
diseases generally?"   These  are  fair and honest
questions, and I shall meet them, as I have endea-
vored, and shall endeavor, to meet  all others,—
fairly, frankly, and  honestly.  I have no  inclina-
tion to shirk any duty that belongs to the work I
have undertaken; I have no wish to slur over any
part of the labor in which I am engaged.
  I admit, then, that our knowledge of many dis-
eases  is much less positive and complete than our
knowledge of pneumonia.   The natural history of
these  has been less accurately and less thoroughly
investigated, and  is  less knowm.   The  causes  of
this difference are various.  Some of these diseases
are more obscure in their nature, and more complex
in their elements and relations than pneumonia is,
so that their investigation is attended with greater
difficulties, and beset by more numerous obstacles.
Others  are of less frequent occurrence, affording
fewer opportunities for their study; or they occur
under such circumstances, as to render this study
comparatively difficult and partial.   Others, again,
being attended with  little or no danger, have not
excited  the same  degree of interest that attaches
to the graver, and more formidable maladies.   But
these  admissions have only a limited application.
To the most frequent, and the most fatal diseases,
they hardly apply at all.  The individual affections,
which,  with  pneumonia, constitute the  greatest
aggregate amount of disease, if I may so speak, 
      THE DEGREE OF CERTAINTY IN MEDICINE.    59

and destroy the largest proportion of human life,
are the  eruptive, periodical, and continued fevers;
inflammation of the membranes of the brain; and
tuberculous phthisis.   Here are some  nine or  ten
diseases, which destroy half, probably, of  the hu-
man race;  and their natural history is  hardly less
complete than that of pneumonia.  Their symp-
toms, their lesions, their causes, their  march and
duration, their complications, their tendencies, the
circumstances which affect,  and which indicate
their degree of danger, and their probable termina-
tion, are all nearly, and many of them fully, as well
and as positively ascertained, as in the case of pneu-
monia.   The difference is only one of degree: it
is very slight;  and  it is  every day diminishing.
And the same thing may be said, with some  quali-
fication, of our knowledge of other diseases.  This
knowledge is of the  same nature as that of  pneu-
monia, rests on the same  basis, is derived from the
same sources, and is daily becoming more positive,
and more complete.
   If it had been my wish or purpose to produce
striking  and  startling effects, by more vivid and
dramatic representations  of the achievements of
medical science, I could easily have done so, and
without traveling out of the records.  I could have
shown our science, with its nice and delicate senses,
catching the first faint, ominous sign of commenc-
ing tuberculous deposition in the pulmonary tissue,
watching and following its increase and develop-
ment from week to week, and from month to month;
noting exactly all  its changes—its softening—its 
60
AN INQUIRY INTO
discharge from the body—and then counting the ca-
vities left in the lung, and defining their bounda-
ries-—taking the exact gauge and dimensions of
the living and beating  heart,  measuring the varia-
tions in the thickness of its wails, and the capacity
of its cavities, marking out the circumference of its'
orifices—as they are enlarged or narrowed by dis-
ease,—and detecting every disturbance in the play
and adjustment of its  delicate valves;—seeing in
the slight frown on the forehead of the young child,
the end from the beginning,—the dim cloud on the
horizon, no bigger than  a man's hand, that shall
yet so soon spread its sable pall over the sky, and
blot out the light of life.  But my object has been
to present a plain, unvarnished, and faithful state-
ment of the nature and  extent of our  knowledge
of disease, avoiding even the appearance of exag-
geration, and keeping carefully out of the picture,
not only all false, but even all high coloring.
  To give anything like completeness to our in-
quiry into the  nature  and extent of the power of
medicine over  disease, it is  necessary  to  state, at
least in general  terms, the  degree of  this  power
over the several forms of disease to  which the
human  body is subject.  To make this inquiry
absolutely complete, it would be necessary to go
into a detailed  examination  of the therapeutics of
every individual  disease of  any considerable im-
portance, such  as I  have already bestowed upon
pneumonia.   My purpose,  however, will be suf-
ficiently answered by  a  few  statements and illus-
trations of quite a general character. 
      THE DEGREE OF CERTAINTY IN MEDICINE.     61

  There is a much wider difference between dif-
ferent diseases, in  our power  of curing and con-
trolling them, than there is in  our knowledge of
them.   The latter is inconsiderable; the former is
enormous.    I  will now indicate  briefly, but  as
clearly and definitely as the present state of science
will justify me in doing, the actual power of  medi-
cine over the  principal forms of disease.  In their
relation  to  this  subject, diseases  fall naturally
enough into  certain family groups, the individual
members differing somewhat amongst themselves,
but  still resembling each  other sufficiently to  be
conveniently considered in this manner.
  The first group consists of  diseases of slight or
very moderate severity, rarely endangering life,
and terminating almost always spontaneously, after
a few days' continuance, in health  Amongst them,
and  as representatives of the class, I may mention
common catarrh, simple acute diarrhoea, and simple
jaundice. These diseases, in their ordinary forms,
uncomplicated, and occurring in adults, are not only
attended with  no  danger,  but, as a general  rule,
they subside and disappear in the course of a few
days.   For  these reasons, they are  often left en
tirely to themselves, at least so far  as  any active
treatment is concerned.  Still, they are more or
less  under the influence and control of medicine.
The effects of remedies upon them may have been
less  minutely and philosophically investigated,
than in the case of more dangerous affections, but
these effects  are matters of daily observation ; there
is no more doubt  about them than there is about 
62
AN INQUIRY INTO
the  connection  between  a west  wind  and fair
weather.  An inflammation of the mucous mem-
brane of the upper  portion of the air  passages is
often arrested or very greatly modified  by a single
dose of an opiated diaphoretic, and the  same thing
is true of simple diarrhoea.  Some of these slight
affections are more  under the  control of  remedies
than*others; they may be generally safely enough
let alone; but most of them may be favorably in-
fluenced by an appropriate medication,—mitigated
in severity, and shortened in duration.
  There is another  group pretty nearly allied  to
the  foregoing in some respects, and differing  con-
siderably from it in others.  The diseases belong-
ing to  it are  somewhat graver than those  of the
first group, though they rarely destroy life.  Func-
tional  dyspepsia,  chorea,  and  chlorosis,  may be
mentioned  as  members of this family.  If their
causes are removed, these diseases will, at least in
many instances, spontaneously cease, but this tend-
ency is not so strong as it is  in  the first group.
The influence of remedies over some of these af-
fections is very marked and  striking.   Take, for
instance, chlorosis,  that most common and  well
characterized morbid condition.   When entirely
simple, not complicated with any other pathological
element, it is almost always absolutely under the
control of remedies. The physician orders his corro-
borating chalybeates, and a nutritious animal  diet,
with the fullest and most  undoubting  reliance on
their efficacy.  He expects them, almost as a matter
of course, to renovate and enrich the impoverished 
      THE DEGREE OF CERTAINTY IN MEDICINE.    63

and watery blood, to bring back the faded color of
the cheeks and  lips, and  to infuse fresh strength
and vigor through the debilitated frame; and he is
very rarely disappointed.   This disease, as I have
already said, does not tend directly to destroy life,
and it is accompanied with very little positive suf-
fering ;  but  it has no  natural tendency, like many
other diseases, to go through certain regular stages,
and then to  cease  spontaneously,—it is not self-
limited ; it is a source of much annoyance and dis-
comfort ; it  unfits one more or less for the active
duties of life ; it sometimes lays the foundation for
other and more serious diseases, and if our science
and  art had  done nothing else  than to ascertain
the effects of iron upon this  malady, they  would
have given a gift to humanity that ought at least
to shield them from the blind and bitter assaults
of arrogant  ignorance and wooden-headed stu-
pidity.
   In  the third group, I shall  include diseases
which do not ordinarily destroy life, but which are
somewhat  graver  than  most of the  foregoing.
Many of them tend towards a natural termination
in health, and with the common aids of rest and
regimen, they would generally so terminate, inde-
pendent of all active remedies.  In this group may
be placed sporadic dysentery, simple acute rheuma-
tism, . acute  pleurisy, tonsillitis,  catarrhal  croup,
and so on.   Some of these diseases are very much,
and others very little, under the control of art.  In
the latter category,  for instance, are tonsillitis and
rheumatism.  We  have no uniform  and reliable 
64
AN INQUIRY INTO
means of relief, in these two diseases; the control
of  art over them is very limited in extent;  its
power is very uncertain and contingent; sometimes
it makes itself  felt, and at others it wholly and al-
together fails.   Sporadic dysentery, and catarrhal
croup, on the other  hand, are very much under
the control of art.  An adequate dose of opium in
the former, and an emetic in the latter, are almost
invariably followed by prompt  and very decided
relief.
  The fourth group is a very extensive, and a very
important one,  and more miscellaneous in its cha-
racter  and composition, than any of the preceding.
It includes most of the more serious local inflam-
mations,  and  all the general fevers,—continued,
periodical, and  exanthematous.    Hooping-cough,
Asiatic cholera, erysipelas, and  delirium  tremens,
may be placed in this class.  Most of them are
more or less self-limited,—that is to say, they tend
to go through a certain series of processes, and then
to terminate either in  death,  or in health, and the
direction of this tendency depends upon the grade
and severity of the disease.  Pneumonia belongs
to this class, and the detailed remarks already made
in relation to it, are more or less applicable to the
other individuals of the class.   I do not  mean to
say, that the effects of remedies upon these diseases
are as  great and  decided as they are upon pneu-
monia; this would be an exaggeration; generally,
they are not so;  I mean, merely, to say  they are
of the same character.  The mild forms of most
of these diseases, and even those of considerable 
      THE DEGREE OF CERTAINTY IN MEDICINE.    65

severity, tend, like simple pneumonia in a young,
robust person, very strongly towards a  favorable
termination, and in  a great majority of instances,
they reach this termination, quite independent of all
active remedies.  The graver and more malignant
forms of the same diseases, like extensive or double
pneumonia in an old person with a deteriorated
and feeble constitution,  tend as strongly in the op-
posite direction, towards a fatal termination, which
also they generally reach, in defiance of medical
art.   Simple scarlatina almost always terminates
naturally, and spontaneously, in health, without
the aid of any active remedies:  so  does distinct,
benign  small-pox: so does  mild yellow-fever: so
do the milder forms of periodical, and of continued
fever; while the grave, and malignant varieties of
all  these diseases,  very frequently terminate in
death, and are only to a very limited extent, or not
at all, under the control of art.  Then there is an
intermediate set of cases, in which the two  anta-
gonist tendencies are nearly balanced, and in which
the prevalence of one or the other may often be
decided  by  the judicious interference, or by the
entire neglect, of active medical art.
  These diseases differ  so widely amongst them-
selves, in their relation to remedies, that it is diffi-
cult to speak of them in general  terms.  Some of
them  are  more obviously and more uniformly in-
fluenced by remedies than others.  There is no more
doubt, for instance, of the favorable effects of blood-
letting upon inflammation of the pericardium, of
the liver, of the  kidneys, than there  is of these ef-
    5 
66
AN INQUIRY INTO
fects on pneumonia.   There is no more doubt of
the efficacy of wine, in certain stages and condi-
tions of British typhus, than there is of the effects
of antimony in pneumonia.  Every day, there are
multitudes of patients with this disease, as directly
and obviously saved  from death  by  active stimu-
lants, as  the life of a famishing  man  is saved by
food.   And we find here one of the most constant,
and one of the most  important of all  therapeutic
relations—I mean that between periodical fever
and Peruvian bark.  The power of opium to allay
functional spasm, and to abate  neuralgic pain; the
antiphlogistic action  of antimony, in inflammation
of the lungs; the effects of an emetic in catarrhal
croup, of iron in chlorosis, of wine in low typhus,
are not more invariable  and  certain,  than is the
power of cinchona to  control and arrest the periodi-
cal element, in the great family of malarious fevers.
The simple forms of these diseases  do, indeed,
very commonly subside and cease; they rarely de-
stroy life immediately and directly; but their re-
peated occurrence at length undermines and breaks
down the constitution, while in their more violent
manifestations, they are as suddenly fatal as yellow
fever;  and for the prevention  of these results, we
have one reliable and heroic  remedy—cinchona.
Somewhat as I  said of  iron in chlorosis,  this
gift  to humanity  is  a boon  and a  blessing,  that
ought  to secure for medical science and medical
art the deep and everlasting gratitude of the world.
   The graver forms of the diseases belonging to this
class are to a great extent beyond the powers of art. 
      THE DEGREE OF CERTAINTY IN MEDICINE.     67

Confluent small-pox, algid epidemic cholera, malig-
nant scarlatina, and  the adynamic and ataxic forms
of typhus and typhoid  fever, not only very fre-
quently  terminate in death, but  they seem to  be
very little influenced, in any way, by remedial mea-
sures.   The vital forces are so profoundly impaired
and perturbed, that  they no  longer respond to the
strongest appeals; they have ceased  altogether  to
recognize or to feel their accustomed relations.  But
sometimes, even in this class  of cases, it is very cer-
tain that  life is saved by the timely appliances of
art.   Patients  with  malignant scarlatina,—the sur-
face cold and purple—the pulse rapid  and thready
—the respiration quick and panting—all the powers
of life suddenly  and completely overwhelmed  by
the subtle and  potent poison  that pervades the sys-
tem,—are  sometimes  apparently  snatched  from
death by the assiduous application and administra-
tion of external and internal stimuli; and similar
remarks  may  be made  of  the  analogous forms
of other diseases belonging to this class.  It should
be added farther, that although in the milder forms
of many of these diseases, tending naturally to ter-
minate in recovery, there is no evidence that active
remedies  exert as great an  effect as they do  in
pneumonia; there is still ample proof that they are
sometimes and in some degree serviceable.  Taking
these diseases together, it would  be going too far,
unquestionably, to say that life  is as frequently
saved by medical art, where  it would otherwise  be
lost, and  that they are as uniformly mitigated  in
severity and  shortened in duration by this  art,  as 
68
AN INQUIRY INTO
pneumonia  is, but the difference is one of degree
only;  and when we have made allowance for the
fact that the family of continued and eruptive fevers
are less under  the control of medicine than any
other grave diseases which so generally terminate
favorably, and that we have but few remedies bear-
ing a special relation to individual diseases, like that
of antimony to pneumonia, we shall be  justified in
concluding that the amount of this difference is not
very great.
   Our fifth group is constituted by a most formi-
dable and appalling catalogue of diseases—having
no tendency towards a favorable termination ; but
little or not at all under the control  of remedies;
and  self-limited only  by death.   To this  class
belong hydrophobia, epilepsy, traumatic tetanus,
scirrhus and cancer, softening of the brain, tuber-
culous meningitis, phthisis, membranous croup, dia-
betes,  albuminuria, and various  structural lesions
of the heart and other viscera.   Most of these dis-
eases  are, in the present  state of science, beyond
the reach of medicine,—some of them nearly, and
others absolutely so.   Amongst thousands of cases
of hydrophobia, there are not half a dozen authentic
examples of recovery;  the disease has  an  invinci-
ble tendency towards  death.  Epilepsy sometimes
ceases; it is often mitigated by treatment; it is
occasionally cured ; but it has no constant or uni-
form therapeutical relations; there are no means
for its removal to be relied upon with any degree of
confidence, and it generally resists all.   Traumatic
tetanus, when fully formed, is less invariably fatal 
      THE DEGREE OF CERTAINTY IN MEDICINE.    69

than hydrophobia, but it generally terminates in
death, but  little influenced  by art.   Scirrhus and
cancer may be removed by the surgeon's knife, and
the rapidity of their progress in some degree  re-
tarded ; but they have a  strong tendency to extend
and  to reproduce themselves, and the pharmaco-
poeia contains nothing by which this tendency can
be resisted.  Softening of the brain, and tuberculous
meningitis so  constantly  destroy their victims, that
it is a question in science whether any ever escape.
Tuberculous consumption, the universal endemic,
as Broussais calls it, has an  immemorial  and me-
lancholy celebrity, which renders it  unnecessary
for me  to  say much about it.  In temperate lati-
tudes, it  destroys one-fifth of the human  race, and
no climates are exempt from its ravages.   The an-
nual mortality from  it in England alone is  sixty
thousand.   Its tendency  is towards death, a termi-
nation which it generally reaches.  This tendency
is very  strong, but  not  absolutely and invariably
invincible,  as it is in many of the members of this
mournful family.  The strength of this tendency is
not  very unfrequently diminished  by art;  it is
sometimes  arrested, or  it sometimes ceases.   Con-
sumption is sometimes cured.  But here, again, it
is true that wTe have no settled and reliable means
of cure.   The treatment and the remedies that  seem
to have been effective or  beneficial in one instance
fail altogether in  others ; and in by far the largest
number,  the disease goes on its downward  way,
p-ivino- but  slight heed or none to our efforts to mo-
too       ra
dify or arrest it.   Membranous croup occasionally, 
70
AN INQUIRY INTO
 but very rarely, yields to remedies;  albuminuria
 and diabetes are often mitigated, and their duration
 probably prolonged, but they are hardly ever cured ;
 and the great family of visceral structural  lesions
 are  for the most  part utterly irremovable  by art.
 Doleful and terrific as is this gloomy catalogue, it is
 still incomplete.   In the foregoing sketch of its dis-
 mal characteristics, I certainly cannot be accused
 of having anything extenuated, and I  wish, before
 leaving the subject,  to make  two remarks.   In the
 first place, although  art is generally unable to arrest
 these diseases, and to prevent their termination in
 death, it still does much, at least in many instances,
 for their alleviation.  If  it  does  nothing  else, it
 occasionally defers their final period ; and very ge-
 nerally it renders less rough and painful than it
 would otherwise  be the pathway to the tomb; it
 brings rest if not healing on its  wings; it takes
 some drops of bitterness from the cup which  it can-
 not remove ;  it smooths the  pillow, and it spreads
 tenderly the  couch of our last long sleep.   In the
 second place, although this has nothing to do .with
 the question  of the  actual extent of the power of
 medicine over disease, still in  common justice to our
 science and art, it should  be  remembered, that the
 fault of their  inability to control and to cure these
diseases  may not  be in any degree justly charge-
able upon them.   It is true that we can assign no
limits  to the powers of art.   The history of  the
 past, the nature of the human mind and  of all  hu-
 man knowledge,  sanction and encourage at least
 the rational hope of boundless improvement and in- 
      THE DEGREE OF CERTAINTY IN MEDICINE.    71

definite progress, and the brilliant discoveries of the
last few months  may have well kindled into enthu-
siasm our own anticipations of the future.  I trust
that the day may come when tuberculous  menin-
gitis shall be arrested as we now arrest catarrhal
croup, and when the daily hecatombs of consump-
tion shall be no  longer piled up.  But in this phi-
losophical inquiry, bright hopes are not to take the
place of rigorous inductions, and we are not to for-
get that the foregoing  diseases may be in them-
selves—in  their very nature  and constitution—
incurable   In the manifold and  boundless variety
and the daily increasing number of the  products of
art—in the novel and infinite combinations of the
laboratory, or in the yet unexplored fields of na-
ture,—there may  be found  a remedy  for  hydro-
phobia; but there may  be no  such  remedy.  We
have  no right  whatever to assume  that there  is.
Such an assumption is wholly and absolutely gra-
tuitous.  The  existence  of the  remedy  can  be
shown  only by its discovery;  and this discovery
the assiduous efforts of two thousand  years  have
failed to make ; it may never be made,  and that for
the simple reason  that  it is not in nature.  The
common  and favorite fancy that every poison has
its antidote, and every disease  its remedy, is the
dream  of the optimist, and not the positive decision
of reason and philosophy.   Our best and most ra-
tional hope in regard to the most frequent and fatal
of these diseases is, that we shall finally succeed in
a good degree, if  not  entirely, in removing  and 
72
AN INQUIRY INTO
avoiding their causes, and so preventing  their oc-
currence.
  There are a few diseases  differing  in  some re-
spects from those of the  preceding groups, which,
in this general estimate of the powers  of medicine,
it is important not to pass over.   These are diseases
which have little or no  tendency to terminate in
heallh; some of which, on the other hand, have  a
strong contrary tendency, but which are, neverthe-
less, to a great extent,  under the control of art.   I
refer  particularly  to syphilis, scrofula, and some
chronic  affections of the skin.  The most  striking
and  important of these diseases is  syphilis.   The
offspring of excessive and irregular animal indulg-
ence, and  its terrible scourge  and avenger; its
poison,  when received  into the system, and not
counteracted by appropriate treatment,  extends and
multiplies  itself, till the  entire economy  becomes
its prey, till every fibre and every fluid of the body
is involved in its  foul contamination, and this fair
and goodly fabric,
        "The cunning'st pattern of excelling nature/'

is changed to a reeking mass of loathsomeness and
abomination.  No pen or pencil  can caricature  or
exaggerate  the features  of this  hideous  malady.
The famous representations of the plague, in the
wax gallery at Florence, are in no degree more re-
pulsive  and  appalling than are  its common and
everyday manifestations.    And then to add a new
element to the accumulated horrors of  this disease,
it is  transmissible from parents  to their offspring; 
      THE DEGREE OF CERTAINTY IN MEDICINE.    73

so that  the  sins  of  the  father are literally visited
upon the children.  Now,  for all  this  we  have
effectual and almost infallible remedies.  The dis-
ease may almost always  be entirely rooted out, and
the system completely, or in a good degree, restored
to its original condition.   With the actual passions
and weaknesses  of  humanity, no imagination can
conceive  the extent and variety  of  wretchedness
that must have flowed from this disease, unchecked
and uncontrolled by art.
   I should  leave  this portion of my subject, and,
indeed,  my  whole inquiry,  altogether incomplete,
without a statement of the relation of  medical art
to the process of child-bearing.  Women generally
bring forth their children, according to the primeval
sentence, it  is true, in sorrow and in  suffering, but
still in  safety, without the succor or assistance of
what can properly be called  medical art.   This is
the  arrangement  and ordination of  nature.  But
this arrangement is very frequently more  or less
seriously interfered with and disturbed; it is some-
times defeated altogether.   Child-birth is a  com-
plicated and more or less difficult  process; it is
always  painful; it is frequently tedious;  it  some-
times becomes utterly and  absolutely  impossible,
without the  interference of art, and it is always
subject  to a great variety of accidents and contin-
gencies.  Some of the difficulties which  occasion-
ally beset this process are such as nature is entirely
unable  to overcome; they involve the certain and
unavoidable death both of mother and  child.  These
difficulties can  always  be  surmounted  by art; 
74
AN INQUIRY INTO
 sometimes  readily  and  completely,  saving  both
 mother  and  child ;  at others less readily and  less
 completely, destroying the child, or leaving the fate
 of the mother, or the child, or of  both,  uncertain.
 Even in the more favorable, ordinary, and  natural
 manner  in which the  process is accomplished, very
 great assistance is frequently derived from art,  and
 there is  rarely a case in which this assistance may
 not be of service, in  lessening the amount of suffer-
 ing,  and in diminishing  the  chances of danger.*
 In no department  of medicine is watchful,  assidu-
 ous,  competent and  skilful art of  more signal  ser-
 vice than  in obstetrics.   This is so little doubted
 anywhere, that it is quite unnecessary to insist upon
 any  proof or illustration of its truth.f

  * At its  appropriate place, in a subsequent part of my inquiry, I
 have referred to the newly-discovered agents for the prevention of
 pain during surgical operations.  Some of my readers may be sur-
 prised at the omission from the text of a similar reference here. In
justice to myself and to the subject, I wish to say that I have partici-
pated, and still participate fully in the enthusiasm which these brilliant
and extraordinary discoveries have excited in the popular and the
professional mind.  I do not doubt the value of these agents in dimin-
ishing the sufferings of child-birth; and there is good ground to hope
that they will be found of  great service in the treatment of various
diseases; but they have not  yet been  applied to a sufficient extent,
with sufficient care, and under a sufficient variety of circumstances,
positively and definitively to determine their value.
  t I may add here, in passing, that in no branch of practical medi-
cine can there be required more knowledge, skill, sagacity, sound
judgment, promptitude of decision, and self-possession than in this.
An accomplished  and safe obstetrician must be an accomplished
physician.  And this is the  obvious and sufficient reason why this
branch of practice should remain where it now principally is, in the
hands of thoroughly educated medical men, and not in the hands of
partially educated, and, therefore, wholly incompetent midwives. 
       THE DEGREE OF CERTAINTY IN MEDICINE.     75

   Surgery has escaped almost entirely the charges
 of incompetence and uncertainty, which have been
 so liberally bestowed upon practical medicine.   The
 reasons of this are simple and obvious enough.   Its
 processes  are  not only more  showy than those of
 practical medicine,  but  they are  more easily seen
 and apprehended;  they appeal immediately and
 strongly to the senses;  they are  so manifest, that
 they can be neither  doubted nor mistaken.   The
 restoration of  a dislocated bone to its socket; the
 removal of a calculus from the bladder, either  by
 the lithontriptor,  or  by the  knife and forceps; the
 closure of an  aneurism  by a ligature on  the dis-
 eased vessel;  the instantaneous arrest of the spout-
 ing torrent of  blood  from a cut artery; the  re-ad-
 mission of the long-excluded light to the  retina,  by
 the withdrawal, or the dropping down, of the dark-
 ened curtain of the  crystalline lens, are achieve-
 ments  so brilliant in their execution, and so strik-
 ing  and positive  in  their results, as not  merely to
 leave no room  for cavilling or for skepticism, but to
 excite in us at once,  emotions both of wonder and
 delight.  And we may now add, that surgery does
 its most  formidable work,—sundering  the  large
 limbs, with its bold and  free incisions, rending  by
 main force  the  ligamentous fastenings, and the
 strong adhesions of anchylosed joints, and carrying
The objection that this  arrangement is a violation of womanly deli-
cacy and propriety, is ridiculous, and has no sense in it.  The idea of
indelicacy never enters  the  mind of the practitioner, and it can very
rarely enter that of a chaste and pure woman.  It is answer enough
to this objection, that it is less and less felt with the advancement of
civilization and refinement. 
76
AN INQUIRY INTO
its exploring probes amongst the exquisitely sen-
sitive  filaments of exposed  and  irritated  nerves,
whose every slightest touch has heretofore  been
intolerable agony,—doing all this, I say, and more,
—after having  steeped the senses and the mind in
total  unconsciousness, or lapped them in positive
elysium.  But there is no essential difference, after
all, between  the certainty of surgical and the cer-
tainty of medical  art.  The processes and opera-
tions of the surgeon, like the medicines of the phy-
sician, are his means for the removal  or mitigation
of disease,  and  like the latter,  their  efficacy and
success are always more  or less contingent and
uncertain.   I mean to say  by  this, simply, that
great and  unequivocal as is  the power of surgical
art over disease, that of medical art is none the less
so; they are both subject to similar conditions, and
their degree of  certainty is much the same.
  There is still another service of inestimable value,
which medical  science and  art have rendered to
humanity,  in ascertaining  and  pointing out  the
causes of disease, so  that, by the avoidance or re-
moval of these, disease itself may  be prevented.
Many of these  causes, and those,  too, most widely
spread, and most powerful in their action, are wholly
unknown  to  us.   It is doubtful whether they are
not in  their nature  inscrutable—not  susceptible of
being  ascertained;  and  even if ascertained,  it is
very probable, that they would still remain as much
as ever beyond  our influence or  control.  All this
is true of the subtle and mysterious agencies, which
give rise to the most important  and  fatal forms of 
      THE DEGREE OF CERTAINTY IN MEDICINE.    77

endemic and epidemic disease,—periodical and yel-
low fever,  influenza, Asiatic  cholera, and  so  on.
The essential nature and composition of these etio-
logical  poisons have thus far wholly eluded  the
diligent search  that has been  made  for them, and
it is not at all  improbable that  they will forever
continue to do  so.   But, in regard to many other
forms of disease, this is not the case.  Their causes
have  been, in  good part at least, ascertained ; or
rather the circumstances and conditions which favor
their occurrence have been ascertained.   In many
instances, these circumstances and conditions  are,
in part, at least, such as may be avoided or removed,
and so the diseases which they occasion prevented.
British typhus,  that terrible accompaniment of
crowded wretchedness and destitution, is the direct
offspring  of  well-ascertained  agencies,—agencies
of our voluntary and artificial creation, and by the
entire removal of which, there  is every  reason to
believe, the disease might be wholly extirpated  and
destroyed.   Some  of the  most  prolific sources of
tuberculous phthisis are well known, and by con-
formity, on our part, to the  inexorable  laws  and
conditions of physical  well-being, they might be
very speedily and entirely dried  up; and the same
thing is true of  many  of the  minor maladies—
dyspepsia, nervous disorders,  and so on.   It is not
that science  herein has  been  faithless to  her high
mission, or unsuccessful in its fulfillment; it is not
that she has failed to discover  these laws, or neg-
lected to promulgate them, with  all the inevitable
penalties attached to their violation, that these  dis- 
78
AN INQUIRY INTO
 eases continue their unabated and dreadful ravages;
 it is that we ourselves give no heed to her warnings,
 and refuse or neglect to obey the laws which  she
 has pointed out.   Science has done its duty; it is
 we who have not done ours.  In this connection,
 also, I may, more appropriately than anywhere else,
 allude to the almost entire extirpation of small-pox,
 through the agency  of vaccination.  I  could  not
 have  found nor chosen a more fitting conclusion to
 this long and brilliant catalogue of  the achieve-
 ments of medical science and  medical art; it is
 the richest gift that our science has ever laid on  the
 altar of humanity; let it  be  the  crowning rose of
 the garland we have woven for the august and god-
 like forehead of the genius of our art.  In the gene-
 ral  exemption from the ravages of small-pox, which
 we have now enjoyed for nearly half  a century,
 we are  likely to forget, and to under-estimate  the
 dread, the suffering, and the mortality that formerly
 followed in its train.   It was one of the most fear-
 ful  scourges of our race; loathsome and malignant
 in its  character;  but very slightly influenced or
 controlled by art; propagating and extending itself,
 multiplying and  reproducing its contagious poison,
 with a constancy and a prolific energy belonging
to no  other disease; attacking, with a like remorse-
less and indiscriminate fury, all ages, and all consti-
tutions,—the young and the old—the robust and
the feeble—the  rich and the  poor;—and where it
failed to destroy, leaving  always behind it its dis-
figuring traces;  limited by  no  circumstances of
time or place, but prevailing throughout all seasons, 
THE DEGREE OF CERTAINTY IN MEDICINE.
79
and in every  climate;—such  was  this terror  of
princes and of people.   By the artificial substitu-
tion of a slight disease, attended with neither suf-
fering nor peril, and hardly giving rise even to a
temporary and passing inconvenience, this  fright-
ful and fatal malady is either wholly prevented,  or
shorn of all its danger.  The immortal discovery of
Jenner  was a triumph of true philosophy,  fairly
and legitimately won—which the wildest dreamer
could hardly have imagined; and it constitutes one
of the richest  blessings which this philosophy has
conferred upon man.
   I have already remarked  that my inquiry has
had especial and exclusive reference to the science
and art of medicine, as this science and  art have
been  generally taught, understood, and practiced,
for the last two thousand years.   Before conclud-
ing my subject, it is proper  enough that I should
say a word or  two about certain medical doctrines,
and systems of practice, differing very widely from
those  which I  have been examining, and claiming
to be sounder and more successful.  I allude,  as
every body will at once understand, to homoeopa-
thy and  hydropathy.   It would have  given me
great  pleasure to  have instituted a fair  and full
comparison of these claims with those of what may
be called, at least as a matter of  convenience, and
by way of marking the distinction, legitimate me-
dicine.  But the data essential to such a compari-
son do not exist; at any rate, I have been unable
to procure  them.   I suppose  the tables  of Dr.
Fleischmann, quoted by Dr. Forbes, furnished the 
80
AN INQUIRY INTO
most authentic and conclusive testimony that could
then be found in favor of the superior excellence
and  efficacy of the homoeopathic system.  In re-
gard to these tables, I can only repeat what I have
already said, that they fail utterly and  entirely of
proving any such thing.   Such tables prove  no-
thing, except that a large  proportion of certain dis-
eases terminate in recovery, and a large proportion
of others terminate in death,—a fact that stood  in
no particular need of any  new proof.  The nature
of the  evidence necessary in  order to establish  the
actual and relative value of different remedies and
methods of treatment,  must be apparent enough to
all who have gone through  the present  inquiry,
although this subject  has  been only partially and
incidentally  considered.  In  the vast and  complex
science of medicine, this is the most difficult thing
to be done.   Its successful accomplishment requires
a more thorough and exact knowledge  of  disease,
a longer continued, more extensive,  and more assi-
duous observation at its bed-side, sounder judgment,
a more devoted loyalty to  truth, more  entire free-
dom from all prejudice and  passion, a  nicer ana-
lysis, a more rigorous and inflexible logic,  than  are
necessary to attain any other  end in the   science.
Now, so far  as I know, and I say this deliberately
and without qualification, homoeopathy has, in no
single instance, on a scale of sufficient  magnitude
to be of any value, complied with  the  conditions
which  are  absolutely necessary in  order  to ascer-
tain the actual and comparative efficacy of its me-
thods of treating disease.  If  it has done so, I have 
       THE DEGREE OF CERTAINTY IN MEDICINE.    81

 failed  to find it out.  If it can point to any such
 researches as those of Louis, and Jackson, and
 Grisolle, I am yet to learn whose and where they
 are.
   I shall now lay down my pen  and close this in-
 quiry  with a single reflection.  I think that medi-
 cal art as  it has  been  embodied  in the lives and
 labors of its professors,  during two thousand years,
 has been worthy its high vocation, true to its great
 trust, faithful to its almost divine mission, and that
 this is more true of it now than it ever was before.
 I claim for it no exemption from  the imperfections
 and frailties of all  human concerns.   I  am very
 willing to admit that the personal conduct, and the
 scientific, professional, and general attainments of
 medical men have  not always come  fully up to
 the requirements  and obligations of their position.
 Knaves find their way into all places, and
         " Fools rush in where angels fear to tread."

   Snobbishness, in the  comprehensive meaning
 which Punch, in his genial pages of mingled wit
 and wisdom, has recently given to the term, is not
 confined to the other ranks and occupations of life;
 so much of it as appertains to the liberal professions
 has not been monopolized by the pulpit or the bar.
 Ignorance  every day puts on the  mask of know-
 ledge, and  pompous  inanities  pass current for the
 profoundest wisdom.  Huge  piles of stubble  and
rubbish are every year heaped up  into shapeless
ugliness, the fond  builders believing all the while
that they are rearing temples of adamant and mar-
    6 
82              AN INQUIRY INTO
ble, and the work goes bravely on to the admiring
sound of braying asses, mistaken for the music of
eternal fame.  Sangrados ply the lancet and warm
water in  Paris as they did in Salamanca,  and
Sganarelles reason in the pages of the last journal
as they do in those of Moliere.   Nevertheless, and
notwithstanding all this, it is  none the less true,
that the obligations of the world  to the science and
the art of medicine, as they have been taught and
practiced, are beyond all measurement or estimate.
There is no process that can reckon up the amount
of good which they have conferred upon the human
race;  there is no moral calculus that can grasp and
comprehend the sum of their beneficent operations.
Ever  since the first faint dawn of civilization and
of learning, through
        11 The dark backward and abysm of time,"

they have been  the true and constant friends of the
suffering sons and  daughters  of men.  Through
their ministers and disciples, they have cheered the
desponding;  they have lightened the load  of hu-
man sorrow; they have dispelled or diminished the
gloom of the sick chamber; they  have plucked
from the pillow of pain its thorns, and made the
hard couch soft with the poppies of  delicious rest;
they have let in the  light of joy upon dark  and
desolate dwellings; they have rekindled the lamp
of hope in the bosom  of despair; they have called
back  the radiance of the lustreless  eye, and the
bloom of the fading  cheek; they have sent new
vigor  through the failing limbs;  and  finally, when 
       THE DEGREE OF CERTAINTY IN MEDICINE.    83

 exhausted in all their other resources, and baffled
 in their skill—handmaids of philosophy and reli-
 gion—they have blunted the arrows of death, and
 rendered less rugged and precipitous the inevitable
 pathway to the tomb.   In the circle of human du-
 ties, I do not know of any, short of heroic and peri-
 lous daring, or religious martyrdom and self-sacri-
 fice, higher and  nobler than those of the physician.
 His daily round  of labor is crowded  with benefi-
 cence, and his nightly sleep is broken that others
 may have better  rest.   His whole life is a blessed
 ministry of  consolation and hope.   Sweeter than
 the water-brooks to the panting hart are his kindly
 voice  and his affectionate smile to the lonely pre-
 sence of sickness, sorrow, and pain.

       11 At his approach complaint grew mild,
          And when his hand unbarr'd the shutter,
         The clammy lips of fever smiled
          The welcome that they could not utter."

   With these convictions of the  powers and capa-
 bilities of our art, and of the general worthiness of
 its practitioners, we may rest assured, if we are
 only true to ourselves and to it, that the regard  in
 which it has been  held since the days of Hippo-
 crates is in no danger  of being permanently with-
 drawn.   We must needs be visited occasionally by
 medical  as by manifold other delusions; but it is a
 part of  their nature always to pass rapidly away
 and to be soon  forgotten.   They are like fluttering
 eddies that cross  the  main  current of the Missis-
sippi or  the Amazon;  to  him who happens to be 
84
AN INQUIRY INTO, ETC.
 caught in the tiny whirlpools, they may seem like
 the majestic tide of the great river itself, but they
 are soon  inevitably lost and swallowed up in the
 rush of its resistless  waters, to appear and to be
 seen no more.  No, there is no danger.   The work
 of two thousand years is not to be  demolished by
 the noisy clamor  of  a few  penny  trumpets.   As
 certainly as there is truth in the foregoing inquiry,
 will the present feeling of distrust towards our sci-
 ence and our art pass away.  The ancient confi-
 dence will be restored; the old love will come back
 again, truer and deeper for the transient and pass-
 ing estrangement.  The constellations themselves
 —Orion  and the  Pleiades—are sometimes appa-
 rently blotted out  from the heavens, by the  gor-
 geous glare of rockets and other artificial fireworks,
 kindled with  sulphurous and nitrous compounds;
 but, courage! my friends, and a  little  patience,—
 the show will soon be over;  the parti-colored flame
 that would rival and eclipse the planets is even now
dying away; all that will remain  of the blazing
illumination will be some noisome  gases in the at-
 mosphere, and a few burnt out sticks on the ground;
 but lo! still looking down upon us, with their dear
old  smile of affectionate recognition, from their blue
depths in the firmament, undimmed in their bright-
 ness and  unchangeable in their  beauty, the ever-
 lasting stars.
THE  END. 
 
 
 
NLM032887682