RESPONSE  TO A PROFESSOR,
AND A
SPECULATION  ON THE  SENSORIUM.
By Bennet Dowler, M. D.

        NEW-ORLEANS.
    WELD & CO., PUBLISHERS.
SOUTH-WESTERN PRINTING OFFICE, 107 POYDRAS STREET.
1850. 
 
A  RESPONSE TO A PROFESSOR,
AND  A SPECULATION ON THE  SENSORIUM.

       By Bennet Dowler  M.  D. of New Orleans.
   [Professor Le Conte, of the University of Georgia, in a communica-
 tion published in the New York Journal of Medicine for March, 1850,
 in referring to my  " contributions to Physiology," which appeared in
 the New Orleans Medical Journal for November, 1849, expresses  sur-
 prise that I did  not mention his " experiments and conclusions  on the
 seat of volition  in the alligator," published in the New York  Journal
 for November, 1845 :  In the very next sentence after that in which this
 complaint is made, Professor Le Conte's own statement, presents as I had
 supposed a satisfactory vindication of my conduct as to that gentleman's
 interesting experiments as given by me in the July number of the New
 Orleans Medical Journal, for 1848.  During the following year, (1849,)
 the " contributions" appeared.   In preparing that paper, I,  at first
 intended to give a second time, a full account of Professor  Le Conte's
 able and original paper, not to do justice to him;  that I  had already
 done  ; but to fortify myself by an authority of so high a character, and
 I now regret, not for his sake, but my own, that I abandoned my original
 purpose.  That  purpose, I abandoned not merely because the restricted
 limits of the  Journal made it  necessary to exclude the greater  portion
 of my own experiments, as well as the Professor's, but chiefly, because it
 appeared to me,  after further  reflection, inexpedient  to repeat in  the
 same  Journal, what had been  already inserted only a few  months  be-
 fore ;  though deserving to be reprinted once, in every journal  of medi-
 cine in Christendom—inexpedient, because my experiments and deduc-

  * The response, is included'within brackets; the speculation, isjsomewhat isola-
 ted; but let no one read the one,  without the other.   The response is written
solely  through deference to the opinions of others.   Although advised to  this
course, privately by the editor of this Journal, I did not  think a  necessity existed
until I saw in the estimable Medical Journal, of Augusta, (Ga.,)  a danger  of mis-
apprehension.  I am quite willing to  adopt Professor Le  Conte's maxim : Fiat
justitia etc. 
4
tious were in many respects, fundamentally different from those of Pro-
fessor Le Conte; though corroborative of his, so far as the  phenomenal
history of the alligator after simple decapitation is concerned, with one
exception, which'is this: Professor Le Conte declares that a decapita-
ted alligator cannot have " two separate uml independent centres of vo-
lition," although  his experiments clearly show that the separated head,
as well as the body, had each a » separate and  independent volition.
  Professor Le Conte makes the following statement, in the New York
Journal of Medicine, which is, as I thought,  and still think, a full jus-
tification of  my supposed omission : " Dr. Dowler published in the
New Orleans Medical and Surgical Journal, for July, 1848, et seq., my
[his] experiments quoted in cxtenso, and fully acknowledged their phy-
siological bearings."  " These experiments (.it is myself that is quoted,)
refute the universally  received doctrine which localizes  sensation,  in-
telligence, volition, &c, exclusively in the brain.  After quoting Mr.
Solly's views in relation to the seat of sensation and perception, Doctor
Dowler further says :  ' Now instead of these diluted waters of opinion,
let the reader look at Dr. Le Conte's experiments, massive as  a moun-
tain of granite.' "
  As to " priority in this field of investigation,"  I have yet to  learn
that Professor Le Conte had preceded me,  though,  I concede to him
priority of publication, in crocodilian physiology.   As early as 1841,  I
had ascertained that the reflex theory was erroneous.
  So far as I can learn from Professor Le  Conte's  paper, his experi-
ments on the alligator began, March 10th, 1845, just twenty days be-
fore mine.   The reason why I published my more  recent experiments,
is a very good one, namely, these were witnessed by many  gentlemen,
of high professional standing and moral excellence, whose testimony  it
would be a folly to impeach—a testimony which has been accredited by
the most competent critics, as altogether conclusive, with one or two
exceptions;  exceptions, which appear to proceed, not from any know-
ledge of the character of the witnesses, not from any attempt  to verify
the experiments themselves, but from that  illusory test of truth, namely,
preconceived, pre-advertised opinion.  And here, I beg leave to insert
a single paragraph by way of episode to my " contributions to physi-
ology," inasmuch as these "contributions," so far as they occu py simi-
lar ground with those of Dr. Le Conte, confirm his completely;and it is
verity, rather than priority, which is most  important.  The essay  enti-
tled " contributions to physiology " has called out two dissenting
critics;  the one Hesperian; the other Austral, in geograpthical position;
both write fluently and able ;  both agree very well)<#>«and he dissent  of
both is of a three-fold import: first,  they grieve atthe unanimity  with
which the medical press has approved and encouraged my  humble  la-
bors; next, they agree that I am damaging what they call  physiology,
instead of building it up; and, lastly, they say  that my experiments,
though witnessed  by many most enlightened persons both in and out  of
the profession, cannot be true, and must be " a hoax."  They also have
several minor strokes of wit against my reasoning from "a single  case,"
and they say that ' they are in favor  of patient dissection."   If  these 
 gentlemen will pay me a visit, I will engage to furnish " patient  dis-
 sections "  in MS., enough  for three months' reading and  study,  and
 among these they will find plenty of crocodilians av Inch " drag their slow
 length along "  from volume to volume ; or if these gentlemen are wil-
 ling to encourage,  or even  tolerate  American experiments,  and  will
 send me a publisher, I will, without cost (for the first edition,) put in his
 hands a few volumes of experiments, with  or  without comment.  Of
 wit and logic I  may have none, but of experiments I have an  exube-
 rance—more than  the treasurers of the States of Ohio.and South Caro-
 lina are able and willing to put in print.*
   Professor  LeConte's  experiments relate to decapitation : and   also
 to  the destruction  of the spinal marrow ;  besides these, mine relate to
 vivisections  of the viscera, and the ganglionic or sympathetic system, to-
 gether with transxerse,  not longitudinal  sections of  the spinal  cord,
 with  and  without ^decapitation.  Professor LeConte maintains the
 oneness of volition in the divided animal;  I regard volition in the
 divided animal, as assuming  a  plural character, because the divided
 portions manifest  sensational and  volitional phenomena,  not simulta-
 neously, when  completely severed, but in  different times, places,  velo-
 cities and intensities.  Hence there must be in these divided portions of
 the animal, independent faculties, corresponding  to these independent
 phenomenal manifestations ; for it is unphilosophical to ascribe the same
 phenomena in three or more similar cases, to dissimilar  causes, or to no
 cause  at all. The Mississippi river descends an inclined  plane to the
 sea, by the force of gravity ; but is it logical to assert that the Amazon
 and Ganges  descend by different  forces ?  My plans, experiments, and
 results differ essentially from  Professor LeConte's,  and, possibly,  from
 all  others, in showing that  the transverse  division  of  the cord, in the
 neck and trunk, without completely dividing the animal, does not  pre-
 vent the simultaneous action of the head, trunk, tail, -and limbs, in a
 sensational and  volitional manner,  This astonishing  result, to which
 the several witnesses present bore testimony, is one that I intend more
 fully to verify as soon as possible,  by repeated experiments before wit-
 nesses  that cannot be gainsayed by closeted speculators who oppose the
 vis  inertia of their opinion, to  palpable facts that are irreconcileable
 with their system of orthodoxy, or rather, with that of their leaders;
 therefore, when the latter give up this system, the  former ought to do
so too.
  I could quote several authorities showing that defection to the theory
of Bell and others, already exists among these leaders.   Their followers
ou"-ht  not to delay their  conversions too long.  Dr. John Conolly, in
his&recent Croonian Lectures,  published in  the London Lancet, (Jan.
 1850, Am.  Edit.) says:  " The yet unsettled state of many important

  *  My quotations, showing in their own words what physiologists teach  con-
cerning the supposed double functions of the nerves, the spinal roots, the excito
motory system, etc., are scrupulously accurate, and all who deny this,  are bound
 to adduce the proof of iheir assertions.  In every case this  is easier than  experi-
 menting ; easier than the making of books out of books, though not so easy as
following a leader  who does all the thinking for one. 
G
 questions relative to  the nervous system, and the revolution even now
 taking place in its theories, or the mere rising vp of doubts respecting
 that great  and beautiful theory of sensation and movement which
 was once supposed the labors of Sir Charles Bell had settled on sure
 foundation,  tend, at least, to enforce  caution.  Men, now, of middle
'age, find the whole face of physiology to have changed since they were
 students, and the most important parts of the change are quite recent.
   The Med. Chir.  llev. for April, 1j*49, admits that the reflex system
 of Dr. Hall is no longer believed in England,  except by  its  reputed
 father ; or words to that effect. It is probable that if this gentleman should
 renounce this system, the believers in this country would  renounce it
 too, without a sigh, or an experiment, whereby to test its truth or false-
 hood.
   Profe.-sor LeConte, agreeably to the universal opinion, maintains the
 doctrine  of  a centralized sensorium, though he is  forced  by his own
 conclusive experiments, to admit that the spot in which the sensorium
 is located cannot  be in the brain, exclusively, but  must extend to  the
 spinal marrow,  also,  in certain animals, among which he places  the
 alligator—a sure step—a bold step  for a central sensorialist, but still
 not bold enough to meet the actualities of the case.  In relation to  the
 locality of the sensorium, Dr. LeConte says, that " no  half results,*no
 approximatives are sufficient; if sensation and volition are  functions of
 the spinal cord in the lower vertebrata, experiment should give us une-
 quivocal  indications of it;"  but in his concluding remarks, he recoils
 from the  obvious deductions which  his experiments teach  :  " Experi-
 ments were made on the head [of the alligator, after decapitation]—the
 jaws snapped at anything which touched thp teeth,  tongue,  or lining
 membrane of the  mouth";  while, 012 the other hand, to use  his own
 words, " the motions [of  the headless trunk] appear to hav^e been per-
 formed with a perfect knowledge of the end in  view;  they were par-
 ticularly  directed to that end—were volitional—varied according as the
 conditions in which they were elicited, altered ;—the animal seemed to
 know, to intend, and  to accomplish  its definite  object", and yet  Dr.
 LeConte appears to repel  the  inevitable consequences resulting from
 his own experiments; for  he says, " It is hardly  possible to  conceive
 the co-existence of two separate and independent centres of volition
 and sensation in any animal, because we find it impossible to under-
 stand how consciousness can be subdivided", thereby rejecting the very
 thing proved by his experiments.
   Dr. Le Conte does not even hint, much less admit, the possibility of
 a diffused sensorium.  He is a centralist agreeably  to the universally
 received  doctrine of the present day ; a doctrine upon which a few hur-
 ried remarks will be  offered in the sequel, as the present occasion seems
 to demand.  My only motive in contrasting Dr. Le Conte's views with
 mine, is to show  the  nature and extent of  the experiments, and the
 conclusions of each, without presumptuously asserting that he is wrong,
 and I am right*

   * I accept as satisfactory, Dr. Le Conte's explanation of the extensive leap per-
 formed by the separated head of the alligator, which I reported in the contributions, 
7
   The cultivator of science, must abide the developments off time, the
 collision of interest, the shock of passion, and the  scrutiny of talent,
 in the  confident  hope that  the high behests of impartial truth  will
 ultimately  gain  ascendency.]
                    Speculations on the Sensorium.
   A diffused sensorium is less incomprehensible than one wholly cen-
 tralized, particularly in the absence of any structural peculiarity as in-
 dicative of the latter,  not  to mention finality,  or the  adaptation of
 means to ends.   Teleology,  the doctrine  of final causes, though  ex-
 tremely difficult in application, and often conjectural in its results, is,
 nevertheless, a most fruitful principle in physiology, being  rather syn-
 thetical than analytical—a priori, because the a posteriori is not yet
 achieved.  It looks to  the transcendental as a means to the experimen-
 tal ;  while, unlike the vis inertia,  which blindly  broods over the pon-
 derous masses  of unexplained experiment,  the  rubbish of countless
 centuries, it diffuses life and movement everywhere, being  to the  em-
 pirical or experimental philosophy, what the Rosetta stone is to hier-
 oglyphics.   Nothing can be  more unwise than the rejection or depres-
 sion of  this principle by some of the Baconian philosophers.  The all-
 comprehending  mind of Newton,  accustomed to rigid demonstration
 and experimentalism, saw  the immense importance of this principle.
 After reviewing his own vast researches, he observed, towards the close
 of his  life, "it gave him particular pleasure that  his philosophy  had
 promoted the attention tofinal causes."
   Although the essential modus operandi or manner of a finality may
 be beyond mortal ken,  the finality itself is clearly attainable ; as in the
 adaptations of the eye to vision, the muscles  to  motion,  the  teeth to
 mastication, etc.   Harvey was led to  the discovery of the  circulation,
 not by accident,  but by the  mechanical adaptations in the veins by
 means of valves, which showed  the purposes  of  nature  by contriving
 a mechanism favoring  the passage of  the blood in a definite direction.
 He saw how the blood ou   ht to move, and  then  he proved that it did
 so move. In the nervous system adaptation is less manifest, or rather,
 is less known ;  nay, it is not known at all.   One thing appears certain,
 namely, that the theories of nervous action hitherto proposed, not only fail
 to recognize this principle, but run  counter to it, violating the evidence
 that analogy furnishes, such  as an assumed  nervous fluid without any
 structures adapted to its circulation; vibrations, traveling impressions,
 and the like,  belong to  the same category.
   There is no special anatomical point in the brain, in the spinal cord,
 nor in  the  ganglionic system, as yet ascertained by structural adapta-
 tion, for the exclusive purpose of cognizing sensations, independently of

 &c; which he says "was produced by a rapid and forcible  depression of the lower
 jaw reacting  against the plane of the table.   Under  such circumstances, the point
 of contact of the anterior  extremity of the lower jaw with the table, becomes the
fixed point, while the point  of application of the force is transferred to its  posterior
 or articulating extremity.  Upon mechanical principles, such a force,  if sufficiently
 powerful, must project the  head upwards and forwards." (N. Y. Jour. Med., March,
 1850.)  The masseter muscles of the alligator are massive  and strong. 
8
  the peripheral portion of the nervous system.   The neurological tree is
  planted in the midst of the garden, among the other trees of life, all of
  which must suffer from central disease or mutilation, as in vivisections.
  The branches may be lopped off without the  same destructive effects
  which must accompany operations in the centre.
    Where (the skeptical  may reasonably demand) is this sensorial lim-
  bo .'  this seat of intcllectualism and sensationalism? this plenary dual-
  ism  of feeling and willing, of reception and transmission, of convergen-
 cy and emanation, of contact between mind and matter ?  this ens ra-
 tionis '.' this consolidation of the objective and subjective ?  this homo-
 genous Me ?  Is it not rather a spectre from the  idealism of Aristotle,
 and not an honest ghost, but a tenebrosity bom of Nox, daughter of
 Chaos, whose anatomy we know that we don't know ?
   The hypothesis that the entire mass of the nervous system, an unde-
 fined atom or sensorial spot excepted, is the mere instrument ftf this as-
 sumed spot, being nothing but the  conductor to  and from  it,  being
 itself devoid of sensational cognition, is at once gratuituous, improba-
 ble, incomprehensible, and contrary to the experience of mankind.   If
 sensation be wholly due to the  nervous system,  (a questionable point,)
 a property bestowed by the Creator, which we can only comprehend as
 an ultimate fact,  like gravitation,  why should a  tangled veil of hypoth-
 eses be thrown around it,  as an  unknown but omnipotent power, work-
 ing by double sets of undiscovered nerves and traveling impressions,
 fluids, vibrations, etc'.'  Does nature prefer  complexity to simplicity 1
 long routes to short ones ? multiform means for accomplishing the sim-
 plest ends ?   Does she lavish her most exquisite workmanship upon the
 peripheral nerves merely that they  may  subserve, by indirect and  re-
 flex methods,  the purpose  of some unknown  aggregation  of pulpy
 atoms, in the centre,  where, nevertheless, all the pains and pleasures,
 all the healthy and morbid  actions of both mind and  body are to be
 realized or sensationalized exclusively ?    What a  vast amount of in-
 dustry on the one hand, and inertia on the other !   "Marivaux asked
 a young and athletic peasant why he did not work ?   'Ah, sirl' said he
 with a sigh, 'you do not know how lazy I am.' "  Would it  be reason-
 able to require Queen Victoria or  General Taylor, though in the centre
 of the  nation, to do all the work, physical or sensorial, for  the entire
 population ?
   An able critic,  in the Western Lancet,  (Feb., 1850,) in a review  of
 my paper,("Contributions to Physiology,") says,  with great clearness
 and logical force, " we do not see but that it is as rational to suppose
 that nerves may in themselves possess intelligence, as to locate and limit
 the whole mind within the brain, and thereby make the  nerves mere
 mechanical media of sensation  and volition—unintelligible conductors
 of ideas.  The experiments formerly relied on do not,&we think, very
 strongly support  this prevalent opinion.   We are told by some, that
the office of  the nerve is merely mechanical, and  that intelligence be-
gins when the nerve enters the brain, and not before.  This is the most
popular idea of the present day.  We are pleased with  this  idea  of
mind being diffused throughout the entire body—this diffusion of soul 
9
 It is more elevating and expansive than  the one that limits its action
 to one central organ.
   "We do not mean to say that our author has no office for the  brain to
 perform;  on  the contrary, he holds it to possess all the powers hitherto
 assigned to it;  but contends that a//intelligence is  not  confined to it.
 There does appear a  necessity for mind in the nerve, or how could it con-
  vey intelligence."
    The exclusively central theory is both complicated and extremely
 mechanical, without mechanical adaptation—a  labyrinth  of  assump-
 tions, each of which tends but to obscurity,  instead of an intelligent
 plan, or a well  developed finality.  Many of these difficulties are avoid-
 ed by the admission  of a diffused sensorium;  by the  admission  that
 the mind generally, as well as specially, cognizes sensations where the
 changes and impressions really are, whether in the central mass  of nerv-
 ous matter or  in the peripheral portions distributed to the organs, and to
 the surface, the mind feeling in the hand as well as in the  head,  without
 the intervention of traveling impressions along nerves Avhich have been
 strangely denied the  power of sensation,  and which serve as mere car-
 riers for an imaginary sensorial point, wholly unknown, and all this, for
 the purpose of explaining what does not really exist, and which, at  the
 same time, serves but to confuse that which does exist.
   It may be safely affirmed that no one but a central neurologist,  ever
 imagined that touch or taste took place as a sensation in the brain only,
 and not in the  organ impressed or affected; and even  neurologists
 themselves, are always obliged to talk, believe and to  act like other
 people, without any  practical reference to their central  theory.  That
 which does not exist, as a sensorial atom  or aggregation of pulpy, ner-
 vous atoms—or an unknown, yet physical,  excitomotory agent which
 acts in a reflex  manner, or an unknown nervous fluid, or an  unknown
 chemical change, or  some other equally imaginary  agent or agencies,
 are offered in  explanation of  self-evident, ultimate and wholly inexplica-
 ble facts, namely, we are endowed, we know not how, with the power
.to feel, to will,  and to move.
   The doctrine  of a  diffused sensorium, so far from detracting  from the
 importance of the nervou system, as the  agent of sensation, augments
 its high  claims in this respect,  through all its associated  connections
 with each living tissue  of an organized  being;  while,  on the other
 hand the centralists degrade  the most exquisitely organized portion, in
 order to exalt an imaginary pulpy point in the centre.
   That aggregation of elements and phenomena  constituting life, is not
 deducible from a single tissue or organ, since all contribute  something,
 particularly, the nerves and muscles.   Much that is called nervous  ac-
 tion is, without  doubt, due to vitality  or life; and even  the nerves
 themselves, may owe much of their superiority to the vital  principle,
 rather than to any thing inherent in that tissue.   The vital principle, in
 an abstract sense,  is, perhaps, incomprehensible, but as expressive of a
 general fact, j* ;s well understood.  That able observer and writer, Dr.
 Win, P. Hon, uilvocates the vitality of the blood, and suggests most
 ingeniously its applicability as an analogue of sensorial  diffusion.  Dr 
10
Hon savs  " It" the distinct and independent vitality of the Wood can be
established, it will be a fact in physiology, sustaining  by anailo0y, ine
diffused sensorium in the alligator, &c."*  Now, whether  the  blood
contribute directly or indirectly to sensorial action, or is itselt a ceiurai
or peripheral sensorial agent, or a combination of  both agents, certain
it is, that it furnishes one of the essential  conditions of neurological
dynamism.   The blood probably contributes directly,  though suoorui-
nately, to the result termed sensation—for in many instances,  in physi-
ology, as in physics, a special function, or result, has for its antecedents,
not a single cause, but a composition of causes, all of which are essen-
tial to the finality.  The apparently simple path pursued by a planet, is
due to a composition of forces, which  have for their point of  departure
the vis inertia.  The rising of the sun is a result to which the  entire
solar system contributes essentially.                               ,
   Besides, if the blood contributes nothing to the  essential  conditions
of sensation, it certainly contributes to, or forms a part of general vital-
ity, without which, the nervous system is but inert matter.  It may be,
that the life of blood is really the fountain of life to the sensorium itself,
whether the latter be central or peripheral, or a union of both.   Hence,
this may be one of the advantages derived from the universal   iiffusion
of the blood.   Hence,  the temporary or permanent loss of the sensorial
life, which instantly occurs, when the  requisite quantity of blood is pot
transmitted to the general system, by the heart and  capillaries, as in
fainting.  Hence,  the  return of  sensation, and voluntary action, with
the renewal or diffusion of the circulation.  If, with Hume, we  define
" a cause to be an object, followed by an another,  where all the objects
similar to the first, are followed by objects similar  to the second ; where
if the first object had not been,  the second  had  never  existed," the
blood would be found occupying a high place if not a primary element in
sensational causation.  Experimenters admit lhat  the  complete  arres-
tation of the blood (from ligatures,  and the  like  obstructions) causes
the loss of sensation and volition.  The nervous centres,  as the brain
and spinal cord, may be greatly injured ;  large portions  disorganized,
and yet, the patient may live for days, months, years;  but the loss of"
a large quantity of blood is   always speedily fatal.  Hence, this is  the
usual method adopted for killing animals.  Even  an ordinary  blood
letting often causes fainting  which is almost a temporary death, with
loss of feeling and voluntary  motion.   The circuitous logic, by which
exclusive neurologists, seek  to explain  fainting by  means of  the nerves,
is altogether inconclusive.  A short, plain, and direct route is forsaken,
the loss of the vital fluid is   overlooked,   for  the  sake of a  doubtful
theory.
   The nerve-matter, in its isolated state, is incapable of thinking, feel-
ing, and willing, even though these phenomena might be  chiefly  due
to that tissue as inherent properties, yet, one can seldom be sure that a
great function of the system is not the  common result of several tissues
and organs.  The blood in its natural channels, may contribute directly
"*New Orleans Medical Journal, March, 1S30. 
11
 or indirectly to thought.   Again, the muscles probably feel, as well as
 act, independent of the nerves, though only to a limited extent.   The
 latter, may, in every complicated act, contribute directly;  or, they may
 only furnish the essential conditions necessary to the finality,  as in the
 case of the heart's function, where the muscular force is, probably, the
 predominating principle.
    The doctrine  of  a  special, sensorial point,  is  a mere ssumptiona:
 that this sensorial point  cognizes  only by means of  transmitted im-
 pressions, the nerves serving only as mere conductors,  is an assump-
 tion.   The mind  becomes  conscious of  sensation,  without  the in-
 termediate act of an entity or transmitted  impression.  In  fact,  this
 neurological  doctrine  is similar,  or rather identical with  the  explo-
 ded doctrine of Aristotle, concerning images, forms, phantasms, sensi-
 ble species, which are not things, or objects themselves, but their picto-
 ral representation, intermediary agents, connecting  the  sentient  mind,
 with the externalities of nature; in a word, impressions and the result-
 ing sensations.  Locke, also, maintained that the mind  perceived im-
 pressions only, not  things.   Berkeley  saw  the consequences  of this
 doctrine, and was enabled,  thereby, to show that there was no proof of
 the existence of a material world, inasmuch, as the mind could  know
 nothing but ideas,  or  impressions.  Theorists  of  this   school contend
 that as the  mind cannot act where  it is not, it can cognize nothing but
 its ideas, which,  however, answer the purposes  of  realities.  Although
 centralists do not apply the doctrine of impressions to the same purposes,
 namely,  to show the  non-existence of matter, yet they seem virtuedly
 to adopt the fundamental idea as good enough for physiology ; that is,
 they regard one point of the nervous system as appropriated  to the re-
 ception of impressions, which travel along certain, double, nervous
 tracts, in contrary directions.
   The grand  error in this system is, the assumption that the mind can-
 not perceive things,  phenomena and relations, but only  the contact of
 the impressions or ideas of these ; an assumption contrary to common
 sense and universal experience.   The reality of the thing perceived, is
 self-evident, not the  intermediary contact of the idea or impression; and,
 in a practical  sense,  every science deserving the name, rests upon this
 basis ; and  the sceptic is obliged to adopt it in his conduct, though he
 may affect to reject it in his theory.   The relation  between the  mind
 or sensorium,  and the object cognized, requires no intermediate imping-
 ing entity called impressions, but is  a  direct operation, intuitively per-
 ceived as such; as in the case of  a diffused sensorium.
   As the word impression is  mechanical, let us  try it  mechanically,
and see how it will work in the matter of war.   Not long since, Gen-
eral Taylor  made an impression on the periphery of Mexico, on the one
side, while General Scott made  an impression on.the other.  The shot
which they threw into the  walls and castles of Monterey and  Vera
Cruz, did not reach the  sensorial centre  of the nation, that  is, the capi-
tol.  If the impression of spent balls can not only travel, but  do  even
greater execution than the impressing balls themselves, why was it ne-
cessary for General Scott  to cut his way, inch by inch, to the very cen- 
1:.
tie of the city of Mexico ?  How can a physiological impression travel
through the masses of the body,  without its seal,  any more than  a
cannon-ball impression on  the  castle of Sun Juan can  traverse  the
mountains tf Mexico to the national palace without itsmetalic reality '.'
A traveling impression is a fact, or it is not.  If  it be only  a poetical
invention, it ought to  be made known as such.   Who pretends that the
Mississippi is really the father of waters, the  true Adanric progenitor
of all other rivers ?  Where is Eve, the mother ?  As a figure of speech
it is  more flattering than  accurate, seeing the Amazon  is much  more
entitled to that appellation. The sacred writings  say, " God is  a rock;"
but geologists never commit the mistake of inquiring whether he real-
ly belongs to the Silurian or granitic formation. The term impression,
being definite  and mechanical, and with all theoretical, is,  even as a
figurative term, not a judicious one, wherewith to characterize innerva-
tion, or that change termed sensation,  of which we know nothing but
the fact itself:  a change that some ascribe to the circulation  of  a ner-
vous fluid; others to vibration ; others  to chemical action, and so forth.
   Those who admit that a little portion of the nervous  system only is
endowed with a faculty to feel, might as well  admit, at once, the broad
principle, namely, that all parts feel.  Their sensorial logic, as it now
stands, is no better than the ethical reasoning of  the actress, Madame-
oiselle-------, whose  chastity having been called in question, she  de.
fended herself by saying,  that, although she had  had a child, it was a
very little one!
   If any  one atom in  the  centre, or periphery, possesses the power of
feeling, so may every atom, for anything that  can be perceived  to the
contrary in the anatomical arrangement of the nervous system.  There
is nothing to show that the peripheral  nerves are  mere  conductors,  in-
sensible instruments, whose  sole function is to minister to a  sensorial
spot or point in the centre.
  Nor does this central assumption contribute  to prove, what some sup-
pose it proves, namely, the unity of the sentient being, called a person.
As the sensorial spot or mass is  material, and  infinitely  divisible, it is
no more an intelligible type of unity than the  totality of the organized
being.  The unity of a building consists  not  in  a single brick.   The
same is true of the nervous skeleton.
   So far as consciousness is concerned, an affection  of  the periphery,
as a  vaccine pustule, is always referred to the part where the pustula-
tion exists, and not to the  central point assumed as the central sensori-
um commune, as the percipient mind,* and this reference possesses  all
the force of intuitive evidence.
  In no point  of view, whether transcendental or experimental, does a
central sensorium solve the difficulties of sensation, while it is,  in itself,
more difficult to understand  than  any other within  the whole circle.
All that can be known of the nerves,  or  of  matter, both living and

  *The mind alone is sentient and percipient; neither tissues, nerves, or brain
could, of themselves, or from any property or change of which they are capable,
become, in any sense, conscious of their condition.  In the brain alone it |the im-
pression] may be perceived."  [Kirke  & Paget's  Phys., 42, 295. 
13
 dead, is its phenomenal history, not its essential essence, not its inter-
 nalizes.  That the mind is united with the entire body, and not with a
 mere sensorial point, is more than probable.  That the sensorial  activ-
 ity is more concentrated and more complex, and varied in  the  centre,
 than in the periphery, is not denied.
   Is it not  an assumption to maintain that a wound of  the periphery
 is cognized, not at the  place, but  solely in an unknown point  in the
 centre, through the intermedium of transmitted impressions?  May not
 the centre furnish the essential conditions only  to the peripheral  sensa-
 tion 1  Mayjnot the former partake  equally and simultaneously with the
 latter in the cognition ?   Does not every one, in spite  of the central
 theory, refer the pain to  the spot wounded ?   Is the wounded part with-
 out a  sensorium  of its  own ?   Why should it be a  mere tender, or
 a runner to an unknown and  uninjured point in  the brain ?   Why
 should not the injured nerves themselves feel ?  Why should  they be
 but  insensible, passive  conductors ?  What an  endless  complexity!
 The  centralists admit that both hemispheres of the brain are insensible,
 and may be cut down, slice  after slice, to the tubercula quadragemina,
 without pain to the living animal.   Again, pathological anatomy  shows
 that  a large portion of  the brain may be  disorganized by disease, and
 yet, in  many cases, the sensations,  voluntary motions, and the intel-
 lectual phenomena, remain.
   Now, it is questionable, whether the brain, the assumed  seat of sen-
 sation,  cannot better bear  the loss of its substance  than the peripheial
 part  of the nervous system,  ounce for ounce.   Has any one  ever  cut
 away a great portion, not to say many ounces of the nerves from the limbs
 and  surface,  without pain,  not  to  mention death '.'  Is  not  the fact
 vouched for by vivisectors, namely,  that the brain  proper may be  cut
 away in slices without pain,  strong proof against the central theory of
 sensation ?
   The evidence relied on  by the centralists, so far  from  establishing
 their doctrine, appears to me, far more conclusive in favor of a diffused
 sensorium ;  that is to say,  the paralysis, and insensibility resulting from
 the division or disorganization of a nerve, do not prove that the  nerve
 is the mere insensible instrument of the brain.  It is more rational to
 suppose, that, as the nerve of the particular part palsied has been  dis-
 organized, so, according to  all analogy, the function of  this part is,
 from this cause, altered.    Why travel from the part injured,  to a sen-
 sorial point  not injured,  in order to  explain the effect produced ?  If
 the periphery have, as I contend it has, more or less of the  sensorial
 power,  then the phenomena following disorganization of the peripheral
 nerves or sensoria, are such as might  be expected  a priori.  If  the
 periphery were the true sensorium; if  the  br:.in were  its insensible
 instrument,  merely, it  is probable  that  the destruction of the  brain
 would interrupt the sensorial action  and unity  of the surface, because
 no part is wholly isolated or independent  of thtf other parts of the
 same tissue, not to mention the  associated  tissues,  which either con-
tribute towards the common finality, or furnish the essential conditions
for the unity and efficiency of the special function, whatever that may
be. 
14
  Dr. Reid truly says, that, " Sensation can be  nothing else than it is
felt to be.  Its very essence consists in being felt;  and  when it is  not
felt, it  is not.  There is no difference between  the sensation and  the
feeling of it;  they are one and the same thing."   Now, if sensational
cognition be restricted to sensorial point in the  centre of the  brain or
spinal cord, it can only be known  by experience, and every  sane per-
son could testify .to its truth, since this truth,  if truth  it be, is not of
such a character, so recondite as to require profound  learning as in many
astronomical  calculations.   Newton had no more knowledge of nature
of giaviiation, in itself, independent of its  laws, than the savage of the
wilderness.   A  fruiterer can judge as well concerning  the taste of a
sweet or a sour orange, as a La Place.  As, therefore,  the most learned
physiologist is  unacquainted with the nature of sensation, and knows
nothing of any central point adapted to that end, his  testimony is, in
this particular case,  very little better  than that of the  unlearned.  If
we take the testimony of mankind generally, as to the seat of sensation,
perhaps, not one in a million will even so much as think of a point in
tne brain, as possessing exclusive sensational and volitional jurisdiction,
which every one ought to be conscious of,  if it be true.
  If the  fundamental  doctrine  of phrenology be true, the faculties of
the mind have many different seats; a topographical distribution favor-
able to division, though the  system  claims vastly too much for  the
brain;  too much for true science.
  " Phrenologists," says Dr.  Mayo,  " have thrown their work into a
great number of pigeon holes, and  have separated, very arbitrarily, into
small parcels, what more  skilful  theorists  would  have  collected into
larger masses."  [Elem. Pathol. Mind, 20.]
  Partial insanity—derangement of special faculties,  often in relation
to one subject alone, (monomania,) affords a presumptive proof that  the
mind is diffused, rather than concentrated in one  sensorial spot.  That
a single point should be  the seat of all the mental faculties, and their
diseases, and  that a disease of this point should affect one faculty, and
not the others equally seated in this same point,  must appear very im-
probable, and very little analogous  to the pathology  of diseases in
general; as these latter have many seats, and not one  only.
  The entire oneness or  unity of volition, in even the  natural or undi-
vided state of an organized  being, may be questioned.  Simultaneous,
different, and  conflicting trains of  thought, sensation,  and volition,  are
cognizable in both the waking and sleeping states.  In  dreams, in dis-
eases, and in mental  derangement, a multiformity  of  co-existing voli-
tions seems to be indicated  in many cases.  Personal identity appears
to be lost or divided.  The individual imagines himself a plurality or
duality, or trinity ;  one  thinking,  willing,   talking, arguing, disputing,
and acting after a particular manner ;  the other in a manner quite diff
erent.   Suppose a multiform will,  or a leading  will,  with co-existing
sub-wills, the former ruling the latter, (as mesmerists and electro-biolo-
gists pretend to rule their subjects), combining the latter, conformably
to rational ends, when in health, but during sickness, or mental disease,
losing this control and unity ;  then, it might  be  expected, that voli- 
15
tional derangements, a loss of oneness, a loss of combining power, would
take place, as we find from experience.  There appears to be a kind of
special will in many of the organs, which is not attributable to the
general will,  and which is often in opposition to it; and therefore, for
the want of a correct term, called involuntary ;  as the  closure of the
eye, on the approach of an  object that might injure ; the withdrawal
of a limb  from an irritant, during profound sleep ;  the expulsion of an
offending  substance, from the  glottidian aperture;  the ejection  of
ipecac, from the stomach; the foetus from the uterus; and many other
similar acts.  To  attribute these actions to instinct, or refex  action, of
which we know nothing, is less intelligible  than to refer them to a
volitional faculty, of which we know much.   Even the lowest of these
special, isolated, uncombined  actions are  stamped with the volitional
type, not being blind, as instinct  is  supposed  to be, but in a great
degree  intelligential,  having, for  their  purpose, self-preservation.—
Writers take  great pains to exclude the ward volition, from their defi-
nitions, while the facts by  which they illustrate, what they call a
blind power, are but an enumeration  of the  most perfect acts'or ends,
called volitional,  being the actual  finalities aimed at by the latter,
namely, the well being of the individual:
                 " And  reason raise o'er instinct as you can,
                  In this 'tis God directs, in that 'tis man."—Pope.  »
   If the  sensorial spot be so  small that it cannot be seen, how much
smaller must be the little traveling  entities—not metaphors, called im-
pressions !  As no microscope can make them  visible,  it  is  probable
that the strongest believer in their existence would hesitate to take an
oath upon the books of Hypocrites, that he ever  saw one in all his life.
This sentient point, in  men not of one idea, as the Kants, the  Cuviers,
the Shakspeares, the Newtons, and the Franklins, must  be excessively
crowded, and closely packed.
   The functions of the centre, morbid and physiological, are less known
than those  of the circumference, so far as sensation is concerned.  The
same may be affirmed of internal, compared  with external pathology
and therapeutics.
   The assumed indivisible character of sensation, personal identity, and
the like, I wish to avoid as much as possible, since they are metaphysi-
cal questions of no importance, when opposed to palpable facts, show-
ing that the division of an animal, divides its sensation and volition, as
plainly as the body itself.  The doctrine of unity, or personal  identity,
how plausible soever it may be, in psychological  rationations, cannot
destroy facts, though the latter may seem to conflict with the assumed
laws of the spirit-land, of which, however, we  only  know,  that we
know nothing with absolute certainty.
   On the whole, it may be affirmed,  with great probability,  that the
optic, o-ustatory, olfactory, and auditory nerves, as well as those of a
more "-eneral character, concerned in touch, in their natural conditions,
in  connection with the entire system, centripetal and peripheral, con-
stitute so many sensoria for sensational cognition.  Admitting (what
indeed, is not the fact) that the unity of the nervous system is such that 
16
the destruction of any one of these sensoria would render the finalities
of all impossible, still, the doctrine of diffusion, as appertaining to the
whole, as a whole, would not be disproved.   A special sensorium may
be annihilated without destroying the other sensoria of the general sys-
tem.  For example, the loss of the visual sensorium,  or sight, like  the
lost Pleiad, leaves the remainder of the constellation  undiminished in
splendor.
  In conclusion, I beg leave to add the following remarkable passage by
an able experimenter, Dr.  Robert  Whytt,  whose work on  the  Vital
Motions, was published ninety-nine years since, in his native city, Edin-
burgh :   " Not to perplex ourselves with metaphysical difficulties,  we
shall recite a few experiments and observations from which we are led,
by analogy, to conclude that the motions of  the separated  parts of ani-
mals are  owing to the soul or sentient principle still  continuing to act
in them."
  New  Orleans, April  25th,  1850. 
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