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EXPERIMENTAL
RESEARCHES '    /
APPLIED TO
PHYSIOLOGY  AND PATHOLOGY.
       E.  BROWN-SEQUARD,

M. D. OF THE FACULTY OF PARIS, LAUREATE OF THE LNSTITUT DE FRANCE ( ACADEM1!
  DES SCIENCES), EX-SECRETARY OF THE SOCIETE PHILOMATIIIQUE, AND OF
        THE SOCIETE DE BIOLOGIE, OF PARIS, ETC.
          NEW YOBK:
II. I3AILLIERE, No. 290 BROADWAY,
    219 REGENT STREET, LONDON,
             AND
       RUE HAUTEFEUILLE, PARIS.
            1853. 

qr
B?83e
 /?5"3
Entered, according to Act of Congress, in the year of our Lord 1853, by
                    II. BAILLIERE,
        in the Clerk's Oflice, of the District Court, of the
             Southern District of New York. 
I
TABLE  OF  CONTENTS.
                                                             Page.
     I.  On the source of the vital properties,     .       .       .1
    II.  On the reflex faculty,       ....       5
   III.  On the influence of the nervous system upon organic life,.    0
   IV.  On the reparative power of the nervous system,      .      IT
    V.  On turning and rolling produced by injuries of the nervous
            system,    .       .        .       .       .       .ig
   VI.  On  a means of measuring  degrees  of anoesthesia and
            hype roes thesia,  .       .       .       .       .23
   VII.  On the causes of the torpidity of the tenrec,    .       .   25
  VIII.  On the influence of poisons upon animal heat, as a cause
            of death,       .       .              .       .26
   IX.  Action of cold, warmth and light upon the crystalline lens,   29
    X.  On the normal degree of the temperature of man,       .   30
   XT.  Influence of the temperature of one extremity on the tem-
            perature of the body,   .       .       .       .32
   XII.  Coagulability of blood, and its circulation  in frogs, after
            heart has been cut,         .                     .35
  XIII.  On a singular case of animal graft,  ...      30
  XIV.  On  a convulsive affection  produced  by injuries  of the
            spinal cord,        .       .       .       .       .30
   XV.  On  the  relations between the organization  of nerve-tubes
            and their vital properties,       .        .       .      38
  XVI.  On  the  persistence of life in  animals deprived of their
            medulla oblongata, .       .       .       .       .40
 XVII.  Influence of the degree of animal heat on asphyxia,   .      45
XVIII.  On the central seat of sensibility, and on the value of cries
            as a proof of pain,  .       .       .       .       .54
  XIX.  On the mode of action of the most active poisons upon the
            nervous  system, .       .       .       .             57
  XX.  On the crossing of action in the transmission of impres-
            sions in  the spinal cord,     .       .       .       .03 
IV
CONTENTS.
   XXI. On muscular irritability in paralyzed limbs, and its semei-
              ological value,   .       .        •       *
  XXII. On  the  increase of animal  heat,  after  injuries  of the
              nervous system,    .
 XXIII. Cause of  the  stopping of  the heart's  movements, m
              Weber's experiment,    .
  XXIV.  On  a singular action  of air on the  gray matter of the
              spinal cord, in  birds,        •
   XXV.  On the treatment of epilepsy,
  XXVI.  Cure of epilepsy by section of a nerve,   .
 XXVII.  Laws of the  dynamical actions in man and animals,  .
XXVIII.  Influence of  red  blood on muscles and nerves deprived of
              their vital properties,       .        •       •        .88
  XXIX.  Cases of loss of sensibility on one side of the body, and
              loss of voluntary movements on the other side,  .      95
   XXX.  On  the  different degrees of  excitability of the  different
              parts of the sensitive nerve-fibres,    .       .       .98
  XXXI. The auditive  nerve  is a nervous centre,      .       •      99
 XXXII.  On  apparently spontaneous  actions  of  the  contractile
              tissues of the animal body, .       •       •       .101
XXXIII.  On  the cause of the beatings of the heart,    .        .     114
68

73

11

79
80
84
86 
    The papers collected in this book have been published in the Medical
Examiner, of Philadelphia, from  August, 1852, to August,  1853.   They
form  only a part of the author's original researches in Physiology and
Pathology.   A second  will  soon be published, containing the  results of
the author's  experiments and clinical  observations on  some  important
points of the physiology and  pathology of the different nervous centres,
on fractures  of  the spine, on the vital properties of the iris and  of  the
cellular tissue, on the properties and functions of the blood, on  the signs
of death, on  electro-physiology,  on  the laws of cadaveric rigidity and
putrefaction, and on the etiology and treatment of some of the nervous
diseases. 
 
ERRATA.
Page  28, lino 31;  is at, read is not at.
      54,  "  15; animation, read diminution.
  "   55, 1st  note;  Kay, read Fray.
Pages 58 & 75, A.  Barnard, read Cl Bernard.
Page 73, 2d note;  1853, read 1852 ; and add or, ante Art. III., p. 9.
  "  78, line 35;  molar, read motor.
             88;  contraction of or, read contraction or.
  " 103,  "   13;  after muscles, add of this last limb.
 1,1 [116,  "   16;  to account, read easy to account.
 "  117,  "  15 of the note; any, read the.
     "  2d  note; Bologne, read Biologie.
 "  119, line 6; Does  that, read Why does.
 "  "   "   26; minutes, read times.
 ''  "   "   80; any, read a.
 "  123, "   37; so,  read very. 
 
    EXPERIMENTAL  RESEARCHES

                        APPLIED TO

PHYSIOLOGY  AND  PATHOLOGY.

                           BY
               E. BRO WN-SEQUARD,  M. D.;

                        OF PARIS.*
[Reprinted from the Medical Examiner for August, 1852.]
       I.—ON THE  SOURCE OF THE VITAL  PROPERTIES.

  I think that every tissue possesses its vital properties, in con-
sequence of its peculiar  organization,  and that in a  completely
developed animal, nutrition is the source of  the vital properties,
inasmuch as it is the cause of the maintenance of organization.
  I will try to prove the  correctness of my opinion,  by the fol-
lowing remarks on  some of the vital  properties  of  the  spinal
cord, the nerves, and the muscles.

  [* The paper which we have the pleasure of presenting to our readers
from Dr. Brown-Sequard, is  a resume of many researches made by the
author, a part of which only have hitherto  been published in any of the
foreian journals.
  The conclusions arrived at are the result of  eight years exclusive devotion
to the experiments upon which they are based.—Eds. Ex.]
                            1 
2
      a.—Source of the reflex  faculty in the spinal cord.
  Notwithstanding the experiments of Redi, Whytt, Prochaska,
Unzer, Senac,  Fontana, Caldani, Sir G. Blane, Fray, Legallois
and many other experimenters; and  notwithstanding the much
more  important experiments of Marshall  Hall,  Miiller, Grain-
ger,  Volkmann, Kiirschner, Pickford, de  Martino, Buchner,
Mayer, Paton and  Stilling, the existence  of the reflex  faculty,
after the spinal cord has been separated from the encephalon, is
not considered by all physiologists as a proof of the independence
of the spinal  cord.  J. W. Arnold and Flourens  still  maintain
that the medulla oblongata is a centre,  giving  life  to the other
parts  of the  nervous system.  The reflex faculty possessed by
the spinal cord after it has been separated from the  encephalon,
is considered by J. W. Arnold as a remainder of something given
to the spinal marrow by the encephalon, before their separation.
  My experiments prove the incorrectness of that opinion.* I have
found that after having exhausted the reflex  faculty by putting
it in action, energetically  and frequently, in an animal  on whom
the spinal cord is separated  from the encephalon, it reappears,
and becomes  soon as energetic  as before,  provided that the cir-
culation of blood  takes place  in the  cord.  Moreover  I  have
found, that if the reflex faculty is put in action frequently, it is
able  to produce an immense quantity   of  action: thus,  for
instance, it can stimulate  sufficiently  the muscles of  a frog's leg
to make them raise, in an hour and in divided portions, about twelve
pounds, to the height of about  two lines.   In a pigeon the reflex
faculty is able to stimulate the  muscles of a leg so far as to make
them  raise fifty pounds, by fractions, in an hour, to the height
of more than one inch.f
  I  shall add two other  decisive proofs :—1.  The reflex faculty
is very weak in frogs immediately after the spinal cord has been
separated from the medulla oblongata, and it increases after-
wards, as R. Whytt and Marshall Hall have discovered.  I have
stated that it increases so much that  the posterior limbs are able

  * See :—Recherches et  experiences sur la physiologie de la moelle epi-
mere.  These  inaugurate.  Paris, 3 Janvier, 1846.—Comptes rendus des
seances de l'Academie des Sciences.  Paris,  1847  T. xxiv. p. 849.
  tSee Gaz. Med. de Pari?.  T. 4.  1849.   p. 233. 
3
to draw  up,  by reflex  action,  more  than double  the weight
the animal  could raise  up by an action of its will  before  the
division of the cord.  2. After having divided the spinal cord in
the dorsal region  on a  mammal, I kill  it by cutting  the  right
carotid artery.   A  few minutes after  the cessation of reflex
action I inject blood by  the opening made in the carotid.   Then
life returns and with it the reflex faculty.
  All these facts demonstrate positively that the reflex faculty
is a vital property belonging to the spinal cord, and that its
source is in the nutrition which maintains the organization of that
nervous centre.
      b.—Source of the vital property of the motor nerves.
  The independence of  the motor nerves is denied by almost all
physiologists.  They believe  that the nervous  centres are  the
sources of the vital property of  these nerves.   They base their
opinion on this fact, that the motor nerves separated from  the
nervous  centres  soon lose their  property, as it has been seen by
Fontana, Ilaighton, Astley Cooper,  Steinrueck, Miiller, Sticker,
Giinther, Schoen, Kilian,  Stannius, Helmholtz, Martin-Magron
and others.
   But, in the first place, if the motor nerves of the warm-blooded
animals  lose  their  vital property after having  been  separated
from  the  nervous centres, it is not  less positive that they retain
it during several days.   Secondly,  if the vital property  of the
motor nerves is exhausted  by very  energetic  action,  it  re-
appears  after a short time, although  the  nerves are separated
from   the cerebro-rachidian  centre, provided  that the  circula-
tion  of  blood continues  in  them.    Thirdly,  if the  circulation
of  blood  is stopped in  a  limb  in which  the  nerves  have been
divided, it is found that the peripheric portion of the divided
nerves lose their vital property before the muscles.   After the
nerves have been left dead, i. e., deprived of their vital property
for a quarter of  an hour,  half an hour, and even more, blood  is
allowed to circulate anew in the  limb.   Then  the vital property
of the cut nerves  returns, and,  to  produce a muscular contrac-
tion,  only a slight  compression upon them is necessary.*  If the

  * See Comptes rendus de l'Acad. des Sciences.  T. xxxii.  Seance  du 9
Juin 1851.—Gaz.  Medic, de  Paris.  1851.  T. vi, p. 359. 
4
 motor nerves lose their property when they are separated from
 the nervous centres, it is because they are then badly nourished.
 Nerves as well as muscles  must be  exercised, in order to  be
 well nourished.

            c.—Source of the muscular contractility.
   Although there are  some facts which appear strongly to prove
 that the vital property of the muscular  tissue is independent  of
 the nervous  system, many physiologists persist in their opposi-
 tion to Haller's  doctrine on  this subject.   Therefore I have
 thought necessary to  add new proofs to  those already known,
 and I have published many experiments, of which I shall relate
 here only two of the most decisive.*
   1. The sciatic and the  crural nerves having been resected, for
 ten or  twelve days, on  a rabbit or a guinea-pig, I examine if these
 nerves  have completely  lost  their vital  property,  and if the
 muscles are still contractile.   When this has been ascertained, I
 put a ligature around the aorta.  Then muscular irritability dis-
 appears after  a  certain  time and  cadaveric rigidity  appears.
 Three  quarters of an  hour or even  an hour  after the complete
 disappearance of the muscular irritability,  and the appearance of
 the rigor mortis, I cut  off the ligature, and I find, after ten or fif-
 teen minutes, that the rigidity disappears and the contractility
 reappears.  I need not say that the nerves do not regain their
lost property.  This fact  clearly proves  that  the contractility is
 given to the muscles by blood, i. e., by nutrition, and not by the
 nervous system.
   2. Many experiments have shown to me that muscles paralyzed
for five days or a  little more, in consequence of the division  of
their nerves, remain much longer contractile after the death of the
 animal than the non-palsied muscles.  This would hardly be the
 case  if the contractility was given to muscles by the nervous
system.

  * See:—Bulletin de la Soc. Philomat. 1847, p. 74.—Gaz. Med. de  Paris
 1851, t.  vi. p. 619, and 1852, t. vii. p. 72. 
5
          II.—RESEARCHES  ON THE  REFLEX FACULTY.

  During the last seven years I have published many papers re-
lating  to the reflex faculty.*   Among the facts which I have
discovered I will mention the following:
  1. Grainger had found that the act of suckling can be  exe-
cuted by an animal deprived of its  brain.   I have found  that
even after the ablation  of both the  brain  and  the cerebellum,
newly-born rabbits are able to  suckle very well;  which is a
proof that suckling may be executed by reflex action.
  2. It  is commonly  affirmed  that  the reflex  power  is much
stronger in cold-blooded than in warm-blooded animals.  This
opinion is correct so far as regards the contrast between Mam-
mals and Batrachia  (the  animals usually compared); but it is
incorrect if Birds are compared with Reptilia and Fishes. It has
been said that the higher an animal is in the scale the less it
has reflex power.  If this be true,  we should find more and more
reflex power from Mammals to Fishes; but the real order, ac-
cording to my experience is : 1st, Fishes; 2d, Mammals; 3d, Am-
phibia  and Reptilia ; 4th, Birds; so that Birds have more reflex
power  than all the other animals,  and Mammals have more than
Fishes.  Of course, there are exceptions to this rule in the case
of particular  species;  thus the eel,  carp  and  tench have as
much reflex power as many Mammals possess.
   It has also  been commonly affirmed that the reflex  power
diminishes with age, being the greatest in young animals.  This
statement, also, has been based  on a too limited induction.  In
Reptiles and Fishes no difference can be detected in this parti-
cular.   In Birds it is decidedly the other way, the reflex power
being much the strongest in adults.   Among Mammals the dif-
ference is usually in favor  of the  young animal;  not, however,
at the very earliest part of its life, but ten or twelve days after
birth.   As to man the reflex power appears to be greater in him
than in Fishes and Mammals;  but it is  not so  energetic as in
Birds and in Amphibia.
  I have found that the causes of the differences between differ-

  * Sec my Inaugural Dissertation, Paris, 3 Janvier 1846, lere partie.—
Comptes rendus de l'Acad. des Sciences, 1847, t. xxiv. pp. 363 et859.—Gaz.
Med. de Paris, 1849, t. iv. pp. 430 et 644;  et 1850  t. v. pp. 98 et 476.
                             1* 
6
ent animals, as  regards the energy of their  reflex power, are
to be explained by anatomical differences.  There exists a con-
stant relation between the degree of the reflex  power and the
amount of grey matter in  the  spinal  cord.  It  appears, also,
that the mode of circulation of the blood in the spinal marrow
has a  great share  in  the causes of  differences amongst different
animals.
   3. It is  not necessary for the existence of the  reflex power
that the spinal cord should be without alteration.   I have found
the reflex faculty remaining in pigeons after I had crushed the
spinal  cord, and produced in it a considerable alteration.  This
is  important to be  known  by practitioners,  to  prevent their
drawing the conclusion, from the existence of reflex action after
a fracture or a luxation of the vertebral column in man, that the
spinal  cord is healthy.
   4. The influence of the nervous system on the secretions, by
a reflex action, has been very  little studied.   I will  state two
examples of these reflex secretions: 1st, There  is on the face,
and particularly on the forehead and the nose, an abundant pro-
duction of sweat when the nerves of the taste  are  strongly
excited, as they are, for instance, by common salt, pepper, sugar,
etc.   In certain persons the quantity of sweat produced in such
cases is sometimes, even in the winter, very considerable.  2d,
I have observed that it is  sufficient to excite the nerves of taste
in order to produce  the secretion of gastric juice,  bile and pan-
creatic juice.

Ill--RESEARCHES ON THE  INFLUENCE  OF  THE NERVOUS SYSTEM
            UPON THE FUNCTIONS OF ORGANIC LIFE.
   My  experiments have convinced me that if it  is certain that
the nervous system is able to act, and frequently does act, on the
functions of  organic life, it is not the less  certain that the action
of the nervous system  on  these functions  is  not necessary.   I
hope this will be  sufficiently demonstrated by the numerous facts
I  have to relate.

  a. Influence of the section of nerves on nutrition and secretion.
   1.  The frequent occurrence of certain  pathological  changes
after section of the sciatic  nerve in Mammals, has been cited as 
7
a proof of the  dependence  of the  nutritive operations  upon
nervous agency.  I  think the  following  experiments  give evi-
dence  against that doctrine.   I have divided the sciatic  nerve
in a number of rabbits and guinea-pigs, and placed some of them
at liberty in a room  with a paved floor, whilst I confined  others
in a box, the bottom of which was  thickly covered with bran, hay
and old clothes.  In a fortnight, the  former set exhibited an ob.
viously disordered action in the paralysed limbs; the claws were
entirely lost; the extremities of the  feet were swollen, and the
exposed tissues were red,  engorged, and  covered with fleshy gra-
nulations.   At the end of a month, these alterations were more
decided, and necrosis had supervened in  the denuded bones.  On
the other hand  in  the  animals confined  in  the  boxes, no such
injuries  had  accrued ;  and  although some   of them have been
kept living for four, five and even six months after  the division
of the sciatic nerve, no alteration whatever  has appeared in the
palsied limbs except atrophy.  In these cases a  portion of the
nerve  had been  cut off, so  that  reunion was nearly impossible
and did not take place.
   Experiments  made on pigeons have given the same results.
   It is obvious from these  experiments that the  pathological
changes which occur after the  section of the sciatic nerve do  not
proceed directly from  the absence of nervous  action, but that
they are consequent upon  the friction and continual  compression
to which the paralysed limbs are  subject, against a hard soil,
owing to  the inability of  the animal to feel  or avoid it.
   In similar experiments made on frogs, I found that no altera-
tion  took place, except  when water penetrated  through  the
wound, under the skin, and between the  muscles.*
   2. With the help of  an eminent micrographer (Dr.  Lebert), I
have made researches on the influences produced on  the capillary
circulation in consequence of the  section of  all the nerves  (sym-
pathetic and cerebro-spinal  nerves) in the  legs of a number of
frogs.  We have found no appearance of trouble in the capillary
circulation, neither in an hour,  nor in  three or four days after the
division  of the nerves.
   3. When  resection  of  a  long  portion of one of the  sciatic
and the  crural nerves is made  on  a   very young rabbit, guinea-
             * See Gaz.  Med.  de Paris. 1849, t. 4, p. 880. 
8
pig or pigeon, the palsied limb continues to grow  in length, but
it grows only very little, if at all, in thickness.   When the
experiment is  made  on all the nerves of the  wing  in a  very
young pigeon, it is also found that the wing grows in length, but
very little  in breadth or in thickness.  The secretion of quills
takes place equally as well in the palsied limb as in the other.
   The difference in all  these cases between the length of the
sound and  that of the palsied limb or wing  is never very consi-
derable ; nevertheless the length of the healthy parts is greater
than that of  the paralysed parts.
   4. I have found that burns, wounds  and  ulcerations existing
in parts palsied in consequence of the section of  their cerebro-
spinal nerves, are cured as quickly and as well as those in sound
parts.
   5. Atrophy is a constant consequence of the section of the
nerves of a limb.  I have  found that it supervenes not only in
the muscles and the bones,  as J.  Reid has discovered, but also in
the skin, which becomes evidently thinner.
   6. Krimer asserts that after  the  section  of  the nerves  of a
limb in Mammals, the venous blood is of a bright red eolor like
the arterial  blood.  (Physiologische Untersuchungen, Leipzig,
1820, p. 138 exp. 1, and p. 152 exp. 9.)
   Long before the publication  of Krimer, Arnemann had de-
clared that the blood appeared darker than  usual  in a limb on
which all the nerves had been cut.  (Versuche iiber die Regera-
tion an lebenden thieren, Gottingen, 1786, t. i.,  p. 48.)
   Longet (Traits  de Physiologie,  Paris,  1850,  t. ii., B. p.  92,)
says that  he has seen the venous  blood  retaining its ordinary
color  even three days  after the  section  of the nerves of the
anterior limb in dogs.
   Who  is  right—Krimer,  Arnemann or  Longet ?  Neither of
them is perfectly right.  The assertion of Arnemann is entirely
incorrect.   By experiments  made on dogs,  rabbits, guinea-
pigs and pigeons, I have found that the venous  blood in palsied
limbs is evidently less black than it is in sound limbs.  But  it is
not true to say that venous and arterial blood in  paralysed limbs
have the same color.  It is always very easy to distinguish one
from the other.
   The transformation of the arterial blood into venous is not so 
9
complete in the palsied as in the sound limb, but it always takes
place even in a great measure.   There is a  good  proof of this
in the result of my experiments on the  hand and forearms of
two decapitated men.  I injected blood  in the arteries of these
parts thirteen or  fourteen hours after death and when cadaveric
rigidity existed.  Surely  there was  in  that case no nervous
action whatever,  and  nevertheless the  blood, which was of a
bright red color when injected, came  out nearly black from the
veins !
   From all these  facts I shall conclude :
   1st, That the nervous action (that of the sympathetic as well
as that of the  cerebro-spinal nerves) is not necessary for the
change of color of  the blood in the capillaries.
   2d, That the nervous system of animal  life has an influence
upon nutrition by which it takes a share in  the transformation
of arterial into venous blood.
   7. My  friend  Dr.  Cl.  Bernard has  recently discovered the
curious fact, that after the section of the sympathetic nerve in
the neck,  the face on the same side and more particularly the
ear,  become warmer and more sensible than the other side.  The
blood-vessels are much enlarged  and a  great many  are visible
which were not so before the operation.
   I  have  found  that the remarkable phenomena which follow
the section of the cervical part of the sympathetic,  are mere con-
sequences of the paralysis and therefore of the dilatation of the
bloodvessels.  The blood finding a larger way than usual, arrives
there in greater quantity ;  therefore the  nutrition is more active.
Now the sensibility is increased because  the vital properties of
the nerves are augmented when  their nutrition  is augmented.
As to the elevation of the temperature, I have seen, as Dr. Ber-
nard has, that the  ear exhibits, sometimes,  one or two degrees Fahr.
more than the rectum; but it  must  be remarked  that the tem-
perature of the rectum is a little lower than that of the blood;
and as the ear is  full  of blood, it is very  easy to understand why
it has the temperature of  the blood.   A  great many facts prove
that the degree of temperature and of sensibility of a part, is in
close relation with the quantity of blood circulating in that part.
   I  base  my  opinion in part  on  the following experiments : If
galvanism is applied  to the superior portion of the sympathetic 
10
after it has been cut in the neck, the vessels of the face  and of
the ear after a certain time begin to contract;  their  contraction
increases slowly, but at last it is evident that they resume their
normal condition, if they are not even smaller.   Then the tem-
perature and the sensibility diminish in the face and the ear, and
they  become in the palsied side the  same as in  the sound side.
   When the galvanic.current ceases to act, the vessels begin to
dilate again, and all the  phenomena discovered by Dr. Bernard
reappear.
   I  conclude, that  the only direct  effect  of the  section  of  the
cervical  part of the sympathetic,  is the  paralysis  and  conse-
quently the dilatation  of the bloodvessels.  Another evident con-
clusion is, that the  cervical sympathetic send motor nerve fibres
to many of the bloodvessels of the  head.*
   8.  Nearly all  physiologists  believe  that the secretion  of  the
gastric juice is stopped after  the  section  of  the two  pneumo-
gastric nerves.   It is difficult to solve the  question by  experi-
ments on warm-blooded animals, because they die too quickly after
the section of the vagi.  But it is  not so with  frogs.   I have
found that they are able to live perfectly well either after  the
extirpation of the medulla oblongata, or after  the extirpation of
the ganglia of the par  vagum.   In both these cases I have found
that digestion continues to be performed.   Consequently, if  the
gastric juice  is necessary to . digestion, it  is  certain  that this
liquid is  secreted.f

  * My experiments prove, also, that the bloodvessels are contractile, and
that the nerves are able to put them in action.  I have also to remark that
it is a fact, well established by Budge and Waller, that the cervical sympa-
thetic is one of the motor nerves of the iris, and that the  spinal cord is the
origin of the nerve-fibres going from the sympathetic to the iris. Some
experiments, which I intend to perform  again, appear to prove that the
same parts of the spinal cord which give origin to some of the motor nerve-
fibres  of the iris, originate also the motor nerve-fibres going from  the cer-
vical sympathetic to the vessels of the head.   Another conclusion  is to be
drawn from the results obtained by Budge, Waller, Bernard and myself; it
is that the cervical sympathetic, instead of receiving its fibres from upwards
to give them downwards,  receives them  downwards and distributes them
upwards.
  -f-Comptes rendus  de  l'Acad. des Sciences.  Paris, 1847.  T. xxiv. p.
363-64. 
11
  9. J. Reid has found, that if the four nerves uniting the spinal
cord to  the posterior limbs  are  cut across  on both sides,  in
frogs, and if a galvanic current is applied every day to the pal-
sied limbs on one side, these galvanized limbs retain their natural
dimensions,  while the  palsied  limbs not  galvanised  become
atrophied.
  I have found :_1.  That if,  instead of cutting  only the  four
cerebro-spinal  nerves of the posterior limbs, I  divide also the
branches of the sympathetic nerve which unite with them, the
same results are obtained as in Reid's experiment.   2. That if a
like experiment is  performed on dogs, guinea-pi^s,  rabbits and
pigeons, the same results are found.  3. That if  after atrophy
has taken place in the limb of a mammal or a pigeon, a galvanic
current is applied, every day, during  several weeks,  the atrophy
diminishes little by little and the limb at length becomes as large
as a sound limb.   This  happens although there is no return  of
vital property in the divided  nerves.   4.  That if the application
of galvanism is made on the palsied limbs of very young animals,
and continued every day until they have  arrived at adult  age,
these limbs  are then found to have grown as much, in every re-
spect, as the sound limbs.
  In addition to these facts I have to state that  in cases  of  lead
palsy, in which the extensor  muscles, as far as I have been able
to judge, were completely destroyed and replaced by fibrous
tissue, I have seen  muscles created by galvanism and becoming
as strong as they are in healthy men.
  In  a  case,  which I published two years ago,  (Gaz.  Med.
de  Paris, 1850,  t. v. p. 169,)  I  have found that  an  increase
of five centimetres  in circumference  took place  in the  superior
part of the leg of a young gentleman, under the  influence of gal-
vanism, applied three quarters of an hour each day for six  days.
  In  all the facts before related, galvanism acts  by two ways :
the one is that it exercises  the muscles, and  increase in conse-
quence  their  nutrition ; the other is that it produces directly
some of the  chemical changes which constitute nutrition.
  The atrophy, which happens in paralyzed muscles, takes  place
mostly because they remain without exercise, and partly because
when nervous action is deficient the respiration of  the muscles is
not carried on as well  as when the  nervous system acts  upon 
12
 them.   Galvanism  applied to a palsied limb acts partly in  pro-
 ducing  the transformation  of arterial into  venous  blood,  i. e.,
 what Gustav Liebig calls the respiration of the muscles.   I  have
 seen frequently the venous blood, in palsied limbs, becoming as
 black as normal venous blood, after the application of galvanism.
 This change of coloration is not  produced by a direct chemical
 influence, exerted by galvanism on the blood, for if galvanism is
 applied to blood in  a vase, nothing of that kind is seen.   It is in
 consequence of an interchange  between blood  and the living
 tissues  that the change of color happens.   The muscular  con-
 traction which takes place under the  influence of the  nervous
 system, or that of galvanism, produces, in both cases, an increase
 in the darkness of  the venous blood.   This fact proves that the
 consumption of oxygen  by muscles is increased  during their
 contraction.
  I conclude from the preceding facts :—
   1st. Nervous action is not necessary for nutrition.
  2d. Atrophy in palsied limbs is more a consequence of  absence
 of exercise than of any other cause.
  3d.  Muscular  atrophy, at  any  stage,  may be  cured by
 galvanism.

 b.—Influence of the nervous centres on nutrition and secretion.
  1. Every one knows the singular alterations which take place
in the eye after a contusion  of the frontal nerve, or a section of
 the trigeminal or the  cervical sympathetic  nerves.   Every one
 knows  also that the existence of  worms in the intestinal canal,
and also certain affections of the  spinal cord, are able  to produce
 morbid  phenomena in vision, and even  diseases  of the  eye,
 and  especially amaurosis.  I have found that after the  section
 of a lateral half of the spinal cord, it sometimes happens that the
 eye,  on the  same   side where the cord has been wounded, will
present strange and various alterations.  The part of the  cord
having that influence on the eye, lies between the ninth  and the
twelfth  costal vertebrae.  The alteration exists generally in the
 cornea.   In one case a ridge appeared on  the anterior  surface
 of that membrane four days after the  operation.   On the  fifth
 day the ridge was deeper, and its edges had become opaque ; on
 the sixth day all the  cornea was opaque.   It remained so  for 
13
five  days, after which the opacity disappeared and no trace  re-
mained of it, or of the ridge.  This experiment has been  made
on guinea-pigs.
  2. I have found a considerable hypertrophy of the two supra-
renal capsules, on eight or ten guinea-pigs, upon which a lateral
half of  the spinal cord had been cut in  the  dorsal  region, for
eight,  ten  or fifteen months.  These  organs had acquired, in
some of these cases, three times their natural  dimensions, and in
others only the double.  There was no appearance of  change in
their structure.
  By an examination of the supra-renal capsules in guinea-pigs,
on which I had made the section of a lateral  half of  the spinal
cord, a few hours or a few days previously, I have found these
organs  congested, and  sometimes containing  even a slight effu-
sion of blood.   It is very  probable that  such a congestion  has
been the cause of the hypertrophy  found in animals operated on
at a much longer time previously.   The  congestion is  certainly
the  result of  a  peculiar disturbance  in the nervous action.   A
part only of the spinal cord  appears  to  possess that singular
influence on the supra-renal  capsules.   That  part  is  extended,
in guinea-pigs, from the tenth costal vertebra to the third lumbar.
  A simple  puncture of the cord is frequently sufficient to pro-
duce the congestion of both supra-renal capsules.
  3. The researches, made  before mine, as to the influence  of
the spinal cord on the urinary secretion, could  not give a decided
result, because no physiologist had  been able to keep any warm-
blooded animal living a sufficient time, after the destruction of a
large part of the spinal cord.
  The results obtained by Segalas on seme  animals who have
lived from fifteen minutes to an hour after the destruction of the
lumbar part of the cord, had led  him to conclude that the spinal
cord has no influence on the  urinary secretion.  Longet (Traite
de  Physiologie,  Paris, 1850, t. ii. B. p.  199) says :—" Many  ob-
servations have  demonstrated to me  that  the visceral organs,
which  receive their  nerves from the sympathetic, are far from
being immediately paralyzed  by the section of these nerves, and
that their action  is even maintained much longer than the dura-
tion of the experiments in ivhich Segalas had destroyed the spinal
                              2 
14
marrow.* Therefore I think I am allowed to maintain that after
such an injury, the nerves going to these organs, and more par-
ticularly to the kidneys, do  nothing but  spend little  by little
the nervous force, originally and  principally  derived from the
spinal marrow, which is the chief, if not the exclusive centre  of
its production  ; thence the persistence of the renal secretion,  as
well as that of the movements of the heart, the intestinal canal,
the uterine cornua,  etc."
  I could relate a great many experiments proving the incorrect-
ness of Longet's theory, but a single one is sufficient.  I have kept
living, nearly  three months, a  young cat,  on  which the  spinal
cord had been completely destroyed  from the eleventh or twelfth
costal vertebra to its  termination.   This cat has lived  all that
time in  apparently good health, and its urine  has  always been
perfectly normal.  It was acid, as is the case constantly in cats
fed on meat, milk and bread.   The bladder was  palsied, but the
sphincter  vesicae was  generally contracted, so that  every day I
had to  compress the  abdomen and the bladder to empty this
pouch.   When I remained two days without doing that  ope-
ration, the bladder  contracted in consequence of the excitation
produced on its muscular fibres by their distension.
  This fact clearly proves that the urinary secretion is not under
the dependence of the spinal  cord.
  According  to Krimer, the  medulla oblongata is  the  nervous
centre  upon which  the urinary secretion depends.   My experi-
ments prove that this opinion is incorrect:—1st. After the destruc-
tion of  the  medulla oblongata in  frogs, I  have found  that the
secretion of urine remains as  long as the animals have lived, i.  e.,
three or four months.   2d. On hybernating mammals, in winter
time I  have  extirpated the medulla  oblongata,  after having
emptied the bladder.   These animals  have lived a little more
than a day, when I took the precaution  of insufflating air in their
lungs many times each hour.    After their death the bladder was
found full of urine apparently normal.
   The medulla oblongata is not therefore a centre  on which the
urinary secretion depends.
   4. The well known opinions of Segalas, W. Philip, Krimer,
* The italics are Longet's. 
15
Chossat, Longet  and others, about  the influence of the spinal
cord on the functions of organic life, are quite erroneous.  I have
found that birds are able to live for months after the destruction
of the spinal cord, from the fifth costal vertebra to its termina-
tion.   This fact proves not  only that  the  functions of organic
life may continue to exist in such a case, but that they appear to
be executed then as  in healthy birds ;  for, if the operation  has
been made on a young bird, it  will afterwards grow very well.
   I have succeeded  in keeping alive, from the 8th of April until
the 4th of  July, a young  cat, about which I have already pub-
lished a note in this journal.*   The palsied parts in this animal
have grown in length proportionately as much as the sound parts.
The growth has been such in the palsied limbs that they have ac-
quired  more  than  double  the  length they had  at  the  time
of the  operation.   The  functions  of organic life  appeared to
exist without any apparent disturbance.  The nutritive reparation
was so  powerful, that the pieces of the vertebral column which
had been cut off have been reproduced.   This fact is important,
because it shows  that the reproduction of bone is  possible in  a
palsied part.
   The temperature of that cat  was at the ordinary degree, (105°
Fahr., in the rectum.)   The secretion of the hair and nails took
place as in healthy cats.   I had previously seen on birds  that
their  temperature  remained normal after the  destruction of  a
great part of the  spinal cord.   Besides, I have  found in these
birds that the secretion of quills and nails continued to take place.
   As to the influence of the medulla oblongata on the  functions
of organic life, my experiments on  cold-blooded  vertebrata have
proved  to me, that these functions (except, of course, pulmonary
respiration,) may continue  to  exist without any appearance of
disturbance.
   5. After the complete transverse section of the spinal  cord in
mammals or birds, I have found that the ulcerations which  take
place around the  genital organs do not result directly from the ab-
sence of nervous  action.   One  of the causes of these ulcerations
is continued pressure, and another  cause is the continual   pre-
sence of altered urine and fasces.

             * See Med. Exam., No. v. May, 1S52, p. 321. 
16
   My opinion is well proved by the following experiments:—
   1st. I have put, three or four times a day and for many days,
 a certain quantity of urine on the posterior part of the neck, in
 the  neighborhood of the scapulae, upon guinea-pigs.  Before a
 week elapsed, the skin, at the place acted on by the urine,  had
 lost  its hair and epidermis.  After a week more  there was an
 ulceration in the skin, and ten or twelve days later the skin  was
 destroyed, and there was an ulcer with a very bad  aspect. This
 fact  proves how powerful is the action of urine on the skin.
  2d.  On guinea-pigs, upon which the spinal cord was cut in the
 dorsal region, and on pigeons, upon  which the spinal cord  was
 destroyed from the fifth costal vertebra to its termination, I have
 found that no ulceration appeared when I took care to  prevent
 any part of  their bodies from being in a continued state of com-
 pression, and of washing them  many times a  day to  remove
 the urine and faeces.
  3d. In cases where an ulceration had been  produced,  I have
 succeeded in curing it by washing and preventing compression.
  4th. I have found that in animals having the spinal cord  cut
 across, every kind of  wounds or burns were cured as quickly as
 in healthy animals.
  Therefore the ulcerations which appear, in cases of paraplegia,
 do not exist  directly in consequence of the palsy ; they can be
 avoided and in many cases they can be cured.
  These conclusions are perfectly true in  animals having  had
 an injury to the spinal  cord for  a shorter time than a year ;
 but on guinea-pigs, upon which a lateral half of the spinal cord,
 had  been cut for fourteen,  fifteen, or eighteen  months, near
 the tenth or eleventh costal vertebra,  I have found an  alteration
 of nutrition in  the palsied  parts.   It was the right half  of  the
 spinal  cord  which had been  cut, and in such a case, as I have
 discovered, the left side  of the  body behind  the wounded part
evidently loses a portion  of its sensibility,  and its temperature is
also diminished.  I have found, at the time designated, an ulcera-
tion  coming in the  part  between the sacrum  and the  hip-joint.
That ulceration has taken a tolerably  great  extension in surface
but  not in depth.   It  became  as large as  a half   dollar.
 The  part ulcerated has  never  been subjected to  any kind of
compression,  neither  to  the  action of  urine  and   fceces. 
17
Another kind of  disturbance  of nutrition occurred in  these
animals : they lost the hair of the leg, and of the other parts in
which the sensibility was diminished.
  6. It is known that erection is a frequent phenomenon in men
after  a fracture  or a luxation of the vertebral  column.   It is
known also, that  in men hanged, erection and even  ejaculation
are not uncommon.  Segalas says he has seen these phenomena
produced  by the  excitation  of the  spinal cord.   Longet  (loco
cit., p. 201,) declares that he has not seen the excitation of the
cord producing  such effects.  It is very easy to  ascertain, on
male guinea-pigs, that Sdgalas is right.
  1st.  A transverse section  of the spinal cord always produces
an erection and an ejaculation,
  2d.  When  one of these animals is asphyxiated,  erection and
ejaculation take place.
  3d.  If the spinal cord is galvanized, erection and  ejaculation
are produced.
  These facts prove the influence of the spinal  marrow on  the
seminal vesicles.   They  empty  themselves slowly when the  cord
is galvanized.
  In asphyxia, there are universal convulsions even in the mus-
cles of  organic life, as uterus, intestine, etc.  These  last organs
are then  put in  contraction, and it is  not astonishing, conse-
quently, that  the seminal vesicles become also  contracted.   The
cause of these general contractions is the excitation of the spinal
cord by venous  blood, and very probably by a large  amount of
carbonic acid, as I  will elsewhere try to demonstrate.

 IV.—ON THE REPARATIVE  POWER  OF THE NERVOUS SYSTEM.
  I have recently published in this journal*  the results of my re-
searches on the reparative power of  the spinal cord.  From  these
researches I have drawn the  following conclusions:—
  1st.  That the spinal marrow, even in adult mammalia, may be
exposed to the action of the air without danger to the life of the
animal.
  2d.  That wounds of the  spinal marrow may be  repaired.

              * Med. Exam., No. vi., June, 1852, p. 379.
                             o* 
18
   3d.  That after a  complete transverse  section  of  the  spinal
 cord, the functions of that organ may be entirely restored.
   As  to the  nerves,  the  experiments  of Fontana,  Haighton,
 Tiedemann, Flourens, Steinrueck,  and many  others, have  de-
 monstrated the possibility of reunion of the two extremities of a
 cut nerve.   But, in most, if not in all these experiments, the re-
 turn of sensibility and of  voluntary movements have not been
 complete.  The following  fact is, consequently, very important,
 because it proves the possibility of a complete reappearance of the
 lost faculties after the entire division of a nerve.*
   A guinea-pig, on which the sciatic nerve had been  cut across,
 exhibited indications of a return of sensibility a month after  the
 operation.   Two months afterwards the sensibility was increased,
 but was still much inferior  to that of the sound limb.   The mus-
 cles then were beginning to  contract  under the influence of  the
 will.   Six  months after  the  section, the  animal could evidently
 move its  legs and toes voluntarily; the sensibility then was almost
 entirely  recovered.   At  the  end of about  eleven months,  the
 sensibility  and  all  the  voluntary  movements  were  apparently
 alike in the two  posterior limbs.  The animal having been killed,
 it was  found by my friend Dr.  Lebert  and myself that, except
 a slight  union  of muscular  fibres  with  the  nerve at the  place
where it had been divided,  the restoration of the original condi-
 tion was  so complete  that  no indication of the  division could  be
 discovered, either with the  naked eye or with the microscope.   I
 had seen the usual swelling of the nerve at the point of reunion
 about the sixth month after the operation, but at the  time  of the
 last examination it had disappeared.

 V.—ON TURNING AND ROLLING  AS PHENOMENA  PRODUCED   BY
             INJURIES OF  THE  NERVOUS SYSTEM.
   Pourfour du Petit and Mdhee de la Touche  were the first expe-
 rimenters who witnessed turning produced by an injury of  the
 nervous centres.  But the  first valuable researches on this phe-
 nomenon were made by Magendie and Flourens.
   The parts of  the  cerebro-spinal  centre which can  be injured
 without  producing  turning,  are: the cerebral hemispheres,  the
See Gaz. Med. de Paris, 1849, t. iv. p. 880. 
19
cerebellum,  the corpora striata, the corpus callosum, the spinal
marrow and the olfactive and optic nerves.*  All the other parts
of the cerebro-spinal centres are able to produce turning or roll-
ing.
  These circulatory or rotatory movements take place sometimes
on the same side, and sometimes on the side of the body opposite
to that of the  encephalon which has been injured.
  A puncture of one of the following parts produces turning or
rolling on the injured side:
  1st. The  anterior extremity of the thalami  optici, according
to Schiff.
  2d.  The crura cerebri, according to Magendie.
  3d.  The bi, or quadri-geminal tubercles, according to Flourens.
  4th. The pons varolii.
  5th. The posterior part of the processus cerebelli  ad pontem.
  6th. The auditive nerve,  according to my own experiments.
   7th.  The medulla oblongata at the  point of insertion of the
facial  nerve, according to  my experiments in  common with Dr.
Martin-Magron.
   8th. The medulla oblongata outside of the anterior  pyramids,
according to Magendie.
   9th.  A great part of the  posterior  face of the  medulla ob-
longata, according to my experiments.
   The parts of the encephalon which produce turning or rolling
on the opposite side, are :
   1st. The  posterior extremity of  the thalami  optici, according
to Schiff.
   2d. The crura cerebri, according  to Lafargue.
   3d. The anterior part of the processus cerebelli ad pontem.
   4th.  A small part of the  medulla oblongata before  the nib of
the calamus scriptorius and  behind  the  corpora olivaria, accord-
ing to my experiments in common with Dr. Martin-Magron.
   Some of  these two series of parts ordinarily produce turning
and the others rolling.   But  these two kinds of movements can
be produced by the puncture of  a single part of the encephalon.
Rolling is nothing but the exaggeration of turning; thus,  after

  * I consider as a part of the nervous centres, the three nerves of the su-
perior senses: the olfactive, the optic and the auditive. 
20
 a puncture of the medulla oblongata, the animal at first rolls, and
 after some instants, instead of rolling, it turns.  If, when it  is
 turning, a slight puncture is made anew, close to the  first, then
 the animal rolls.
   Before trying to explain turning, I will  give an  outline of
 some of its species.

  1st.  Turning and Rolling caused by tearing the facial nerve.
   My friend Dr.  Martin-Magron  and  myself have  discovered
 that if the facial nerve of a rabbit or a guinea-pig be exposed at
 its exit from the stylo-mastoid foramen, and be then drawn away
 from the cranium, so as  to tear  it  asunder near its origin, the
 animal  begins  in  about five  minutes to turn itself round  and
 round, the movement  being from left to right when  the  nerve
 has been thus torn on the left side, and  from right to  left when
 it has been torn on the right side.   This  rotation  is  generally
 preceded  by convulsive movements of the eyes, of the jaws, and
 of the head  upon the trunk: and the body is then bent  (as in
 pleurosthotonos) towards the injured  side,  by the contraction of
 all the longitudinal muscles of that side, the power of which is
 such as to resist considerable force applied to extend them.  The
 movement at first  takes place in a small circle; but  the  circle
 generally enlarges more and more, until at last, after  twenty or
 thirty minutes,  the animal walks in a straight line.   There is no
 paralysis of any muscles, save the facial.  The effect is not pro-
 duced, unless the nerve be torn close to its origin.
  When the nerve  on the other side also is torn, even after  a
 long interval, instead of the tendency to turn to one side, there
 is, at first, a rolling of the body on its longitudinal axis, which
 takes place  towards the  side last  operated on.  After this has
 continued,  however, for twenty  minutes  or more, the animal
recovers its feet, and begins to turn, as after the first operation,
but towards the other side.   This movement soon ceases.
  Dr. Martin-Magron and myself think  that the cause of  these
phenomena does not exist in  the facial  nerve itself, but  in the
part of  the medulla oblongata from which  this nerve  has  origi-
nated.*
See Gaz. Med. de Paris, 1849, t. 4, p. 879. 
21
2d. Turning and Rolling produced by an injury to the Medulla
                          Oblongata.
   M. Magendie (Precis Elem. de  Physiol. Paris,  1836, t. 1, p.
414)  says :   " Having raised  up  the  cerebellum, I  make a
section perpendicularly to the surface of the fourth ventricle and
at three or four millimetres from the median line.  If I cut on
the right, the animal will turn on the right side ; if I cut on the
left, it will turn on the left side."
   If we suppose a plane cutting the medulla oblongata transversely
at the distance of nearly two lines before the nib of the calamus
scriptorius, the posterior face of the medulla oblongata will be
divided into two parts:  one before that plane, which I will call
superior,  and the other behind, or inferior.
   Now, every puncture  on  that  superior part produces turning
or rolling on the side which has  been punctured.  The slightest
puncture  on  the  processus  cerebelli ad medullam  oblongatam is
able to produce a violent and very rapid rolling.  As long as the
animal lives  after the operation, it rolls or it turns at each time it
tries to walk.
   When  (as  Dr. Martin-Magron and myself have discovered) a
deep section is made on the inferior part of the posterior face of
the medulla  oblongata, before the nib of  the calamus scriptorius,
turning is produced on the side of the body opposite to the punc-
tured side of the  medulla.  A rabbit, which has lived thirteen
days after the operation, had still the circulatory movement a
few hours before  dying.   Nevertheless,  sometimes the animal
could walk nearly  straight during a  few seconds.

   3d.  Turning Produced by a Puncture  or a Section  of the
                        Acoustic jVcrvc.
   Flourens has discovered that, after  the section of the  semi-
circular canals, turning sometimes takes  place.
   I have  found all the facts he relates about this subject perfectly
right.  It was interesting to  know if a puncture  or the section
of the auditive nerve would produce turning.  As it was  impos-
sible to operate on that nerve in mammals, I have experimented
on frogs!  In these amphibia it  is easy to find the nerve  and to
act upon  it.   1 have found that  after a puncture or a section on
the trunk of the nerve,  the animal begins instantly to turn.   As 
22
long as the frogs live, after a puncture of the acoustic nerve, they
turn ; but  the  circle of turning is much smaller a short time
after the operation  than  afterwards.   I  have kept such  frogs
for months.
             4th. On a  New Mode of Turning.
   I have found a mode of turning which has altogether some of
the characters of turning and of rolling.
   In  the circulatory movement called turning (mouvement de
manegeY the body  of  the animal is bent on one of the lateral
sides.  It has the shape of an  arch, and this arch is generally a
part of the circumference described by the animal when turning.
The smaller the radius of that  arch, the smaller is  the circle  of
turning.
   In the new mode  of turning I  have found,  the  body of the
animal  is  not  bent,  and when  it walks  it  moves  laterally,
instead of going forwards.  In turning it describes a circle, but
the longitudinal axis of its body, instead of  being then a part of
the circumference, is a part of a radius, so that its head is at the
circumference, and its tail towards the centre of the  described
circle.
   That mode of turning has been executed by  animals on which
the quadrigeminal tubercles and  the  pons  varolii, on  one side,
had been punctured by a  pin.   One of the eyes was convulsed ;
the other was in its normal condition.  The convulsed eye was
the right  one, and the tubercles punctured  were those of the
left side.
         5th.  On the Causes of Turning and Rolling.
   I have not room enough to show that the theories of Magendie,
Flourens, Henle, Lafargue and Schiff are contradicted by a great
many facts.   I will  only present the following  remarks:
   1st. As the slightest puncture of certain parts of the encepha-
lon is sufficient to produce turning or  rolling,  it is evident that
those rotating  movements  do   not exist  in  consequence  of an
hemiplegia,  as Lafargue, Longet  and Schiff  believe  they  do.
Another reason is that every degree of hemiplegia exist in man
without  being accompained  by turning or rolling.  Besides  these
phenomena have been observed in persons who had no paralysis
at all. 
23
   2d.  The theories of Magendie and Flourens  are also opposed,
by the fact that a slight puncture is sufficient to produce turning
or rolling.
   3d.  As to  the theory  of  Henle, which is  based  upon the
existence of convulsions in the eye, producing a kind of  vertigo,
it  has  against it the facts that,  on one  side, convulsions  may
exist in the eyes without any other disorder in the movements;
and, on the other side,  sometimes turning or rolling exist with-
out any convulsion in the  eyes.*
   Nevertheless, I think that, in many  cases, the vertigo conse-
quent on  convulsions of the  eyes  is one element of the cause  of
turning.  I think also  that, in certain cases, paralysis of some
parts of the  body may facilitate the rotatory movements.  But
their great  cause,  I think,  is the  existence  of a  convulsive
contraction   in   some  of the  muscles,   on  one  side  of  the
body.    These   convulsive  contractions  are  to  be  found  in
every case of circulatory or rotatory movement. As to the cause
of these contractions, it exists in the irritation produced in  cer-
tain parts of the encephalon.

VI.--ON  A MEANS OF MEASURING DEGREES OF ANAESTHESIA  AND
                        HYPERESTHESIA.
   The curious facts discovered by E. II.  Weber, on tactile sen-
sibility, are  well known.  He found  that if  the two  blunted
points  of a pair of  compasses are applied  simultaneously on the
skin, there  is,  according  to certain circumstances,  either the
sensation of  one or of two points.  When the points are both
inside  of certain  boundaries,  they  are  felt  as  one only;
when  they  are  outside  of  these boundaries, both  are felt.
These  boundaries vary exceedingly in  different  parts of the
skin, but for  a given  part the  differences  between men are
not extremely considerable.   I have made  use  of the compasses
for measuring the degrees of tactile sensibility in diseases.  In a
case of  considerable anaesthesia  of the lower extremities, the
patient only  felt a  single impression on one  leg, although the

  * See  a very remarkable case observed by my friend  Dr.  Lebret,  in
Comptes rendus et Memoires de la Soc. de Biologic annee 1850. Paris,
1851. t. ii. p. 7. 
24
points of  the compasses were ten, fifteen, or even twenty centi-
metres apart; whilst on the other leg he could distinguish them
at a distance of twelve centimetres.  The  normal limit is gene-
rally, for  that limb, from  three to five centimetres.  In another
case where anaesthesia was slighter, the limit of the discriminat-
ing power was at from nine to sixteen centimetres.  In two other
cases, in which the diminution of sensibility had not been found
by  the other  means of diagnosis,  the  compass  indicated  a
very slight and beginning anaesthesia.  The limit was at from
six  to seven centimetres.
  These facts, and many others, have demonstrated to me that by
the help of the  compass, a physician can ascertain : 1st. Whether
there is a slight anaesthesia or no.   2d.  What is  the  degree of
anaesthesia.   3d. What changes occur every day in the amount
of anaesthesia.
  The same is true for the cases of hyperaesthesia.   In a case of
paraplegia of the motor power, the patient  felt the two points of
the  compasses, on his feet, even at  the distance of five millime-
tres, whilst a healthy person feels the two points only when they
are  at a greater distance than twenty-five millimetres.
  I shall  add, that for succeeding in such  experiments the two
points must be blunted and applied simultaneously.*
* See Gaz. Med. de Paris, 1849, t. iv. p. 1012. 
25
VII--ON THE CAUSES OF THE TORPIDITY OF THE TENREC, (Erina-
                    ceus ecaudatus, Linn.)
   The influence of cold as  a cause of hybernation has not been
considered essential, on account of  an assumed  fact, which is
altogether incorrect.   This fact is that a mammal called  the
Tenrec, [Erinaceus ecaudatus, Lin.,) which lives in the Islands of
Mauritius, of  Madagascar  and Bourbon, is  torpid under  the
joined influences of warmth and dryness.  Cuvier says, about the
Tenrec:  « They are nocturnal animals,  remaining in lethargy
three months each year, although  they inhabit the  torrid  zone.
Moreover, Bruguiere asserts that it  is during  the  time of  the
greatest heat that they are torpid."   Physiologists have admit-
ted this fact as true, and they have supposed that warmth and
dryness could be, like cold, a cause of torpidity.
   The following facts prove that the torpid sleep  of the tenrec
takes  place from  precisely the  same cause  as   that of  the
hedge-hog, [Erinaceus Europeus,  Lin.,)  and  of  other hyber-
nating mammals:
   1st. The  tenrec and  the  hedge-hog  belong to the  same
family, and they are much alike.
   2d.  According to MM.  Desjardins, Telfair and Coquerel, and
to my own observations,  the tenrecs earth  themselves, and  are
torpid from the month of June to the  month  of November, i. e.
during the winter season  of the Islands where they live.
   3d.  Hybernating  animals,  belonging  to  varied species,
observed  by Pallas, Mangili, Marshall Hall,  Berthold, Barkow,
and myself, have been found torpid at the temperature of 61  to
66° F., (16 to  19° Cs.)  Moreover, I have found that dormice,
(31 us glis., Lin.) even at a temperature  of 65 to 72° F., (20 to
22° Cs.) may become torpid,  and  I  have  observed some that
were  constantly sleeping,  during a  whole  week,  at  a  tem-
perature varying from 59  to 68°  F.  (15 to  20° Cs.)  I  have
stated that hedge-hogs  may be  torpid  during  the summer;
in Paris,  at a temperature of 68 to 72° F., (20 to  22°  Cs.) and
lately, in  Philadelphia, I have seen a marmot (Aretomys monax,
Buff.) torpid, in June, at  a temperature of 71 to 73° F. (21.5 to
23° Cs.)
  4th. During  the time  of its torpiditv, the  tenrec is under
                             3 
26
the influence of a temperature of 59 to 72 or 73° F., (15 to 22
or 23° Cs.) rarely more, and sometimes less.  Therefore  these
animals are exposed to a  temperature sufficiently low to render
them  torpid, for  that  temperature may produce that effect on
the hybernating animals of cold countries.
  From these facts I believe it is right to conclude that torpidity
is induced in the tenrec, in the same way as in the other hyber-
nating mammals, and  therefore it is not necessary to  suppose
that warmth and dryness produce torpidity.

VIII__ON THE INFLUENCE OF POISONS UPON ANIMAL  HEAT AS A
                      CAUSE OF DEATH.
  Prevost and  Chossat,  and after  them, M. Magendie, have
ascertained that  death occurs quickly in mammals  when their
temperature is  notably diminished.   My experiments  confirm
the correctness  of that statement.  The diminution of animal
heat in  mammals, is so dangerous that, in one case, I have seen
death take place in a  rabbit after a diminution of only 22° F.
(12° Cs.)  I have never observed  any animal continuing to live
when  I had diminished its temperature more than 44° F. (24°.5
Cs.) I have found the law established by Chossat perfectly correct,
according to which the diminution of animal  heat necessary for
killing is less and less, in proportion to the rapidity with which
that diminution takes place.
  It is very probable that in all the cases where, in  consequence
either  of disease,  or of a wound,  or  of  poison, the tem-
perature of man is  diminished  many  degrees, his life  is in
danger  from the very fact  of that diminution.   It is  thus in
cholera, in sclerema, in certain cases of palsy, in cases of great
disturbance of the respiration, in  fractures and luxations of the
vertebral column, in the cervical, and even in the dorsal regions,
in cases of profuse haemorrhage, and in many cases of poisoning
when  death is not rapidly produced.
  It has been long known  that  temperature is diminished in
poisoned persons ; and there are but few cases of poisoning on
record in which it is not said that the patient was cold.    Chos-
sat has found  that a  dog,  into whose veins  he  had  injected
opium, had its  temperature diminished from 105°  to 62.6° F.
(40°.3 to  17° Cs.),  22 hours  after the injection.    Brodie  has 
27
found that many poisons act upon animal heat so as to diminish
it  considerably.  Demarquay and  Dume'ril, junior, and  later,
these two experimenters, joined  with Lecointre, have  found the
same thing as Brodie in  many toxic  agents.   I have  made
very numerous experiments on this  subject, and  some of their
results have been published before the last papers of Demarquay,
Dume'ril and Lecointre.*
   I have stated that many poisons,  either injected  in the veins
or absorbed by the vessels of the skin or of the digestive canal,
may  diminish  sufficiently the  temperature  of  Guinea  pigs
and  rabbits, to produce death.   This occurs when the dose of
the poison is  not large enough to kill in less than  four or
five hours.  These  poisons may kill only by their  action upon
animal  heat.  It may be so with  opium, cyanhydric acid,  the
cyanide  of mercury, hyoscyamus, digitalis, belladonna, tobacco,
euphorbia, camphor,  alcohol,  acetic,  oxalic, sulphuric, azotic,
chlorohydric acids much diluted, and some oxalates.
   Of course the action of these poisons is the greater, the colder
the atmosphere ;  but it is not always  immediately so, and in-
stead of  diminishing  the animal  heat, many may increase it
for a time, especially when the temperature  of the atmosphere
is  elevated.
   I have discovered that a dose of one of these poisons,  suf-
ficient to kill an animal, when there is no obstacle to the dimi-
nution of its temperature, may be unable to destroy life when the
temperature of the  animal is maintained by artificial means to
its normal degree,  or  not  far from it.   My  experiments have
been conducted as follows:
   Equal doses of poison were given, simultaneously, to two ani-
mals, as much alike one another  as possible.   One of them
was left in a room at a temperature of  from 46 to 50° F. (8 to
10° Cs.), and the other was kept not far from a  chimney, in a
place where the  air was at from 75 to 86° F. (24 to 30° Cs.)
The first was dead after a certain number of hours, or sometimes
one or two days, having its temperature much diminished.   The
other,  on  the contrary, had no perceptible diminution of its
temperature, and was  generally  cured  very soon.   Therefore,

            * See Gaz.  Med. de Paris,  1849, t. iv., p. 644. 
28
when taken in certain doses, many poisons may kill only by
their influence on animal heat, and physicians, in cases of poison-
ing, should try as  much to prevent the diminution of tempera-
ture, as to expel the poison or to act against it by an antidote,
by pulmonary insufflation,  or  otherwise.
  In  experiments which I have made lately on  the action of
very pure digitaline, that  had been prepared by M. Que'venne,
the celebrated chemist, who has  made such  interesting  and
accurate researches on digitalis and the substances of which it
is composed, I  have found that this  poison may also diminish
temperature.   I believe it is  easy to explain the  contradiction
existing  between  Traube and  Stannius,  as regards the influ-
ence  of  digitalis on  animal  heat.   When  the atmosphere, in
which the animal is, is cold, then its temperature  may be dimin-
ished by digitalis or digitaline, but when  it  is warm the diminu-
tion does not take place, or it is very small. But, of  course, if
the dose is sufficient to kill very quickly, then it  is indifferent
whether the atmosphere is cold or not, because there may be not
time enough for the diminution of the temperature of the animal.
  I have  to  relate another fact which, I believe,  ought  to be
considered as analogous to the  preceding.  It is that kind of
poisoning which occurs when  a  layer of oil, of  varnish  or of
gelatin, is put on  the skin of a warm-blooded  animal.  Death,
then, is  very probably  produced  by a   substance  unknown
until now, and which is secreted  by the skin. The  layer of oil,
varnish, or gelatin  preventing that secretion taking place, that
unknown substance becomes accumulated in the blood, and then
are produced the phenomena  so well studied by  MM. Fourcault,
Becquerel, Breschet,  and Magendie.    I  have  found that in
such a case  the animals may live, if the  atmosphere  in  which
they are kept is at a temperature inferior to  79 or 80° F. (26 or
27° Cs.)  In these  circumstances their temperature is not  sensi-
bly diminished, while it diminishes much when the atmosphere
is cold.   Therefore it is especially  by their  loss of  warmth  that
animals are killed, when  their body has been  entirely covered
with oil, varnish, or gelatin. 
29
 IX.—ON CERTAIN ACTIONS OF COLD, WARMTH, AND LIGHT UPON THE
                      CRYSTALLINE LENS.
    Pourfour  du Petit  has discovered that after  the  death of a
 mammal, it is not uncommon to find the crystalline lens opaque.
 He has found also, that when the lens has become opaque, if we
 draw it near the flame of a candle or a lamp, it  becomes trans-
 parent again  after a few minutes.   The same lens, put  alter-
 nately near and far  from the flame,  may  become  alternately
 transparent and opaque.  I have endeavored to discover whether
 it is the light or the warmth of the flame which renders an opaque
 lens transparent.  I have placed between the lens and the flame
 a layer  of  mineral salt, which is  athermane  and transparent.
 Then the light of the  flame could reach the  lens,  but  not its
 warmth.  There has been no action.  In another experiment I
 have exposed to the light passing  through  the mineral salt a
 fresh  crystalline lens,  still  perfectly  transparent.   It  became
 opaque.   Now, in  a third  experiment, I have compared two
 crystalline  lenses,  perfectly transparent,  one  exposed to the
 action  of  light passing  through  the mineral salt, and the
 other kept  in an obscure place.   The  former became opaque
 much quicker, and considerably more than the other.   There-
 fore, 1st.  It  is not  light which renders transparent an opaque
 lens; 2d.   Light does  not prevent a transparent lens from be-
 coming  opaque ; 3d. Moreover, light  appears to accelerate, if
 not to produce, the opacification of the crystalline lens.
    As to the influence of warmth, it is certain that it is that
 which renders transparent an  opaque lens: 1st. When  left  in
 the atmosphere, at a temperature superior to 70° F. (21° Cs.), a
 fresh transparent lens remains transparent.  2d. When a lens
 has become opaque, it is frequently sufficient to keep it exposed
  to the warmth of the  hand, during some minutes, to render it
•  transparent.   3d. The lower the temperature  of the atmosphere
  the quicker transparent lenses become opaque.
    These  experiments give a very interesting  result, i.  e., that
 li<*ht appears able to produce an effect precisely opposite to the
  effect produced by warmth.
    From these researches I conclude :
    1st.  That  light, and a low temperature, are favorable  condi-
                              3* 
30
tions, if  not direct causes, of the opacity of the lens in warm-
blooded animals after death.
   2d.  That a warm temperature, i. e., a temperature superior to
70° F. (21° Cs.) is a\ cause of the change occurring in the lens,
by which, when opaque, it becomes transparent.
  I will add, that sometimes an analogous opacity takes place in
the cornea.

  X.—ON THE NORMAL DEGREE OF THE TEMPERATURE OF  MAN.
  The degree of animal heat, in the human species, is stated  as
being between 98.5° and 100° F. (37 and 389 Cs.)   I intend  to
prove that it is higher.
   It is impossible to take directly the temperature of  most of
the internal parts of the body in man; therefore many physiolo-
gists, in order to discover the temperature of these parts, have
argued as follows:   According to  J. Hunter, the temperature
of the rectum in animals is the same as that of the right ven-
tricle of the heart; hence it has been concluded that as the tem-
perature of the  rectum, in man—still according to Hunter—is
98°.42 F. (36°.9 Cs.)  the temperature of the internal  parts of
the body ought  to  be  between 98 and  99° F.  (36°. 67  and
37°.22 Cs.)
  Some  other  physiologists, noting the  temperature  of  the
mouth under  the tongue, and supposing  that this  temperature
is nearly the same as  that of the internal parts of the body, have
concluded that the temperature of man is between 99 and  100° F.
(37°.2 and 37°.8 Cs.)
  We will prove that these deductions are not right:
  Firstly, the degree of  the  temperature of the rectum is not,
as Hunter says, 98°.4.  It may be so in debilitated  men, but  in
healthy persons it is more elevated. It is between 100 and  102° F.
(37.7 and 38°.89 Cs.) according to  my own researches  and  to
those of Berger and  Maunoir.   Besides,  many  experiments on
dogs, rabbits and guinea-pigs, have shown satisfactorily to myself
that the temperature of the rectum is not equal to that of  the
right ventricle.  This  last organ is from 1 to  3° F. (0.56  to
1.7° Cs.) higher than the rectum.
  The  temperature of the rectum, in man,  being  between 100
and 102° F. (37°.7 and 38°.8 Cs.),  and  the temperature of the 
31
 right ventricle, in man, being from 1 to 3° F. (0.56 to  1.7 Cs.)
 higher than that of the rectum, if we suppose the same difference
 existing in man as in mammals, it follows that the temperature
 of the right ventricle of the heart in man ought to be  between
 101 and 105° F. (38°.33 and 40°.56 Cs.)
   But a closer approximation of the exact temperature of the
 internal parts of the body, in  man, may be  obtained by taking
 the temperature of an organ situated deeper than the rectum, and,
 consequently, less exposed  to  the influence of the atmosphere.
 Such is the case in the bladder. I have observed its  temperature
 by taking that of  the  urine at the  moment  of its  emission and
 before any sensible  change had occurred in it.  The urine was
 directly received in a vase dipped into a large quantity of water
 at 98° F. (36°.7 Cs.)  Thus I have ascertained that the mean
 temperature of the urine, in man, is 102°.6 F. (39°.2 Cs.)
   Now if we take notice of this  well-known  fact,  that the tem-
 perature of the lower  part of  the abdomen is less elevated than
 the upper part, we are  authorized  to believe that the temperature
 of the central  parts of the body, in  man, is very  near  103° F
 (39°.5 Cs.)
   My experiments  on the temperature of  urine  were  made
 on ten strong sailors,  in the spring, on the Atlantic Ocean,  be-
 tween the 43d and 45th deg. of north  latitude.  The lowest  de-
 gree of the temperature  of urine which I  have  observed, was
 100°.9F. (38°.3Cs.);  the highest  was  103°.2 F.  (39°.56 Cs.)
 My own urine, examined more than thirty times, in  the most va-
 ried conditions, has been nearly always at the same temperature;
 the variations have been only between 102° and 102°.8 F.  (38°.89
 and 39°33 Cs.) The ordinary  degree is 102°.5 F. (39°.17  Cs.)
   Long before my researches,  the temperature of urine, in the
 human species, had been taken by some observers, but in  general
 without sufficient care.   The temperature of the urine is  94°.25,
 according to Braun;  98°.9, according to De Lisle; and 103°,
 according to  Hales.   Recently  Berger has taken the  tem-
 perature of urine in the bladder in five women.  He has found
 it  equal to 101°.48 F. (38°.6 Cs.)
   As  the temperature of woman is a little inferior to  that of
man, the result obtained by Berger is  in  accordance with mine.
   If we take the average between the temperature of the urine of 
32
man as I have found it, and that of woman as Berger has found
it, we have a number very near 102° F. (38°.9 Cs.)
  From these facts we draw the conclusion that the temperature of
the thoracic and abdominal viscera, in the human species and in
both sexes, is between 102 and 103° F. (38°.89 and 39°.44 Cs.),
i. e., some degrees higher than it is generally admitted.

XI.—ON THE INFLUENCE EXERTED UPON THE  GENERAL TEMPERA-
   TURE OF THE BODY BY A CHANGE IN THE  TEMPERATURE OF ONE
   OF THE EXTREMITIES.
   The following sentence  is given, as  an  axiom, by Dr. W. F.
Edwards :  " We cannot either raise or lower the temperature of
any one part of the  body, without all the other parts of the frame
being affected and suffering a corresponding  rise or fall  in tem-
perature, more or less,  according to circumstances."*
   Expressed in such terms, we accept this law as perfectly true.
But the author elsewhere gives  an extension  to this  law, which
we will prove to  be  incorrect.   No doubt when the temperature
of the blood, coming  to  the heart from a remote part  of the
body, has been modified in that part, the thoracic viscera ought
to have their temperature modified ; but to what extent ?  It is
on  this very important point that we  do not agree with Dr.
Edwards.   He was of  opinion that the influence exerted by a
small part, on  all the other parts of the body, was considerable.
He says that the chilling of  a single  part, such as the hand or
the foot, may cause  a loss of temperature  in all the other parts
of the frame, even far beyond what could have been presumed as
likely or possible, and that in a number of experiments where one
hand was plunged in water cooled down by ice, the other hand,
which  was not subjected  to the action of  the cold  bath,  lost
nearly 5°  R. (11°.25 F., 6°.25 Cs.) in temperature.
   It will be easily understood how important it  would be that
practitioners should be able to act on the general temperature of
a patient, so as to increase or diminish it, by means of a  hand or
a  foot bath.  I regret to  say that  if  the  facts observed  by
Edwards are exact, his conclusion nevertheless is incorrect.

  * Article Animal Heat, in Todd's Cyclop, of Anat. and Physiol., 1839,
t. ii., p. 600. 
33
  I have performed, both alone, and  with  the help  of  Dr.
Tholozan, Physician of  the  Hospital  Val-de-Grace  at  Paris,
numerous experiments, with the view of knowing whether  Dr.
Edwards was right or not.  I  have found that the chilling of
one hand plunged in water at the temperature of freezing point,
acted  very strongly on the temperature of the other hand.  But,
at first, there  is no regularity at all  in the quantity of degrees
of temperature lost by the hand which remains out of the water;
and secondly,  we have found once that  this hand  did not  lose
any fraction of its temperature.   In one case we have observed
that the hand kept in the atmosphere did  lose 22° F.  (12°  Cs.)
in seven minutes.  The ordinary loss of temperature has been of
between 6 to 8°  F. (3.33 to 4°.44 Cs.)  In one case  there has
been only a loss of 2° F. (1°.2 Cs.)  In another case  there has
been no loss, and, on the contrary, there has been an increase of
temperature of 1°.4 F. (0°.8 Cs.)
  If,  like Edwards, we consider  the loss of temperature of the
hand  not  plunged  in water as a  sign and as  a measure of the
diminution of the general temperature of the body, we  must
conclude, from our experiments,  that the chilling of a  small part
of thq body may be unable to diminish the temperature of the
body  sensibly, and  that, in other cases, it may act extraordinarily
upon  it.   But the supposition that the hand kept in the atmos-
phere, was able to  give a measure of the modification of the body
is incorrect.  By taking the temperature of the mouth during the
time that one hand was dipped into very cold water, Dr. Tholo-
zan and  myself  have ascertained that the  temperature of the
body  does not sensibly change.   The greatest diminution of the
temperature of the  mouth has  been nearly 1° F. (0°.6 Cs.),
and this only in one case.  In  that experiment in which the
hand  not plunged in  water  lost 22° F. (12° Cs.), the tempe-
rature of the  mouth was not diminished more than the  fifth of
a Fahr. degree.
  As  it is quite  certain that the  temperature of the body is  con-
stantly changing, it is easy to understand why we do not find a
small  but a constant diminution  in  the  temperature  of  the
mouth when one hand is subjected to a notable chilling.  When,
under the unknown influences that are constantly modifying the
temperature of  the  body, there is a tendency to increase  that 
34
 temperature, then  the tendency  to  its diminution  originating
 from the chilling of one hand may exist without producing any
 effect.   We have there two causes acting in  opposite directions,
 and if they are  equal they annihilate each other.  If  they are
 unequal, we perceive only the difference between them.  When
 these  two causes act in the same direction, then their efforts are
 added  to  one another, and it is probably in a  circumstance of
 that kind that I have once found a diminution of 1° F. (0.°56C)
 taking place in  the  mouth.
   We have now to examine how the diminution of the temperature
 of a hand is produced when the other hand  is  dipped into  cold
 water.   A priori it is evident that the chilling of the hand  kept
 in the air exists in consequence, either of the arrival of a cooler
 blood, or in the diminution in the quantity of blood.   That hand
 being exposed to a cold air (for it is only in such a case that the
 experiments  succeed) loses its temperature by the action of that
 cold air.  At first  the blood that arrives in  the hand  is  not
 cooler, as Edwards had supposed it  was.  This we prove by  the
 fact that the temperature  is but-very little changed in the mouth.
 The supposition  then remains  that the quantity of blood ar-
 riving  in the hand is smaller than usual.  This may happen by
 two modes,  one of which  is that the heart  sends less blood, and
 the other that the blood-vessels of the hand are  contracted and
 prevent, in  part, the passage of blood.  It is  certain that the
 heart continues perceptibly to send the same quantity of blood.
 Therefore we are induced  to admit that the hand's blood-vessels
 are contracted.  But  now what is the  cause of that contraction ?
 We will  try to show that  it is in an action of the nervous  sys-
 tem.  Every one knows that'under the influence of a sensation
 or of emotion, the hands, and sometimes the feet, become cold.
 The nervous system, in consequence of that sensation or emotion,
 acts upon the blood-vessels and  excites them  to  contract.   The
 calibre of the visible vessels is  sensibly diminished.   The same
phenomena take place in the two hands when  one is dipped  into
very cold water.  An exceedingly violent pain is felt, the nervous
centres are strongly  excited, and they act then  as under the in-
fluence of an emotion.  Dr. Tholozan  and myself, have observed
that the greater the  pain felt, the more the temperature was di-
minished in the hand left in the air. 
35
  As to the influence of partial heating Dr.  Edwards relates
the following experiment:
  " The hand being immersed in water heated to the temperature
of 34° R. (108*.5F.—42°.5 Cs.)  rose one  degree  of the same
scale, and  the temperature  of other remote  parts not imme-
diately exposed to the influence of heat  were found  to have risen
to a corresponding degree."
  I have repeated this experiment of Dr-. Edwards, and I have
found no evident  elevation in the temperature of remote parts, as
the mouth and the hand, not immersed in water.
  I conclude, then from the facts contained  in this note, that, in
general, the temperature of the body is not sensibly modified
by  the chilling or the heating of a small part of the frame.

XII.—ACTION OF  COLD ON  THE COAGULABILITY GF  BLOOD, AND
   PERSISTENCE OF LIFE IN FROGS AFTER LOSING HALF OF THE
  VENTRICLE OF  THE HEART.
   Dr. Marchal (de Calvi) and other  physiologists, have recently
asserted that cold diminishes  the quantity of fibrine and conse-
quently the coagulability of blood.   I have  observed  a curious
fact, which shows that  blood may possess a  very great coagula-
bility although exposed to  the action of cold.  I have found that
after the  removal of the  half  of  a  ventricle,   in frogs, the
blood may coagulate at the surface of the wound  and  the ani-
mal may continue to live.  After the mutilation has been made,
the lips  of  the wound  are drawn upwards and inside in conse-
quence  of  the muscular  contraction.   The  blood flows  very
abundantly,  but  its  coagulation quickly begins, and a  layer of
solidified blood is soon formed on the entire surface of the sec-
tion, and by this  process the wound is rapidly obliterated.  The
hemorrhage has been frequently stopped in  a few minutes.
   This experiment is successful  only in cold seasons, probably
because  the batrachia  are able to bear much better a loss of
blood at  a low than  at a  high temperature.  The  pulsations of
such mutilated hearts continue with regularity and strength, but
the impulse  given by  the  remaining of the ventricle ought to
be  diminished.   Nevertheless the circulation of blood is accom-
plished well enough to allow the animal to live many months. 
36
   I have shown to the Societe de Biologie at Paris, two frogs on
 which the wound of  the heart was cicatrised  after fifteen days.*

        XIII.—ON A  SINGULAR CASE OF  ANIMAL  GRAFT.
   Every one knows  the  experiments  by which the cock's  spurs
 or many other animal textures have been grafted on the body of
 an animal, and especially on a cock's comb.  I have succeeded
 in grafting  the tail of a  young  cat on  a  cock's comb.  I per-
 formed this experiment in France in 1850.
  After having divided the tail of a young cat, I made a longi-
 tudinal section on a cock's comb, and  I united these two  parts
 one to the other,  by  stitching the cut surface of the cat's tail to
 the cut surface of the  cock's comb.  The skin of the  cat's tail
 had been turned  a little  over  itself, so that  its  internal surface
 was in contiguity with  the cut surface  of  the cock's comb.  Eight
 days after, I punctured the skin  of the tail at a  distance from
 the cock's comb, and blood escaped, so  that it was evident that cir-
 culation was already  established.  The tail had been cold during
 all the  day  of the operation,  but it became  warmer gradually
 from the second  day.  The union appeared  much advanced on
 the third or  fourth day.  The tail was  entirely fixed on the
 eighth day.
  Unfortunately, on the  eleventh day, the  cock had a fight with
 another cock, and the cat's  tail  was torn out from  the ground
 on  which it  had been  fixed.   I was  thus deprived of the
 opportunity of knowing what transformations should have taken
 place in the tail.
  By examining it I found that all its  tissues were fresh, and
 that its blood-vessels contained blood.

XIV.—ON A  CONVULSIVE AFFECTION PRODUCED BY CONSIDERABLE
                INJURIES OF THE SPINAL CORD.

  I have discovered that a  very violent convulsive affection is
the constant result of a considerable wound of the spinal  cord
in certain animals.  It is more especially in guinea-pigs  in whom
a transversal section of a lateral half, or a complete section of

             * See Gaz.  Med. de Paris, 1850,  t. v. p. 169. 
37
 the spinal cord has been made, that this is the case.* The section
 was made at the level of one of the last  six dorsal vertebrae or
 the  two first lumbar.
   When the convulsive fit begins, the muscles  of  the  face and
 neck are the first which contract.   The convulsions occur alter-
 nately in all the muscles of the eye, the face,  the tongue,  the
 jaws and the neck; so that the cause of ihese movements  ought
 to act on the parts  of the  encephalon, from whence the facial,
 the  trigeminal, the hypoglossus, and the motor nerves of the
 eyes originate.   The head of the animal  is  alternately bent
 on both sides  of the body, and lastly the limbs are agitated
 in every direction., In  the  case of a  section of the lateral
 half  of  the  spinal  cord, in the  lumbar region or at  the end
 of the dorsal  region, three limbs only are strongly convulsed;
 the two anterior and one of the posterior—the one that  is  on
 the side  of the body opposite to  the side of the section of the
 spinal marrow.   The other posterior limb has  only very  slight
 movements.   When the spinal cord has been entirely divided in
 the dorsal or  lumbar  regions, the two anterior limbs only are
 convulsed, with the muscles  of the face and  neck. These con-
 vulsions may come without any exterior excitation; but  it is very
 easy generally to provoke  them by frightening the animal, or
 by pinching, burning or otherwise exciting it.   The part of the
 body upon which  a mechanical excitation  acts more powerfully
 is the skin of the face or the  neck.  This convulsive  affection
 has  a great analogy with epilepsy;  but it  has also some dis-
 tinctive features,—for instance, the animals, during the convul-
 sions, do  not  appear  to lose their  consciousness, and  they
 frequently cry when they are pinched.
  The affection  begins generally eight,  ten  or  twelve  day3
 after the spinal cord has been wounded.   The convulsions then
 are  not very strong, and it is  usually four  or  five weeks  after
 the  operation  that  the fits are  violent  and easily produced.
 Three or four months after, the violence and frequency  of  these
 convulsions are diminished; yet in two or  three instances  they
have increased  in strength and frequency more than a year  after
the operation.  The affection may last a long time: in one case
it still existed two years after the operation.
           * See Gaz. Med. de Paris, 1850, t. v. pp. 651, S95.
                              4 
38
   Generally the fits last from  five to fifteen minutes.   The
stronger they )are the shorter is their duration.  For an hour or
two, and sometimes for one or two  days after a violent fit, it  is
impossible  to produce another one by any kind  of excitation.
When a fit takes place a short time after a violent  one,  it is
always weak or very short.
   I have made the following  experiment  on some guinea-pigs
having this convulsive affection : I put them in  a small box, so
that they had but  little room  to move,  and  I gave them food
in great  abundance.   They  then ate very much and were
deprived of exercise, and, in consequence of that mode of living,
they had exceedingly frequent convulsions.   One of them  had
a fit nearly every quarter of an hour. These fits sometimes were
strong, but they did not last long.   The  others had  fits three or
four times  every  day.   I changed  their  mode  of living,  and
put them all in a large room where they had only  a small quan-
tity of food.   The influence  of  this new regimen  was  nearly
immediate; the same day  the number of fits was  diminished,
and in the course  of the  third week afterwards  they  had only
one or two fits; and before long some of them were cured.
  I must relate also  a  very interesting fact analogous  to  the
preceding.   In several guinea-pigs  and frogs, which had  the
spinal cord transversely divided, I have observed  that when  the
animals remained very quiet during  many days, instead  of  the
regular reflex  movements, they had a violent  tetanic convulsion
in  their  posterior  limbs,  when  the skin of these limbs  was
pinched.
  Such  a tetanic  movement  never occurred  in  these animals
when I excited the regular reflex movements every day.
  I have no  room in this  resume  to try to  explain the facts
related; I will do it in a special paper.  I will only add that all
the readers  of this note, who know the views of Dr. Marshall
Hall about  convulsive diseases, will remark  how strongly  the
facts I have pointed out are confirmatory of these views.

XV.—ON THE RELATIONS EXISTING BETWEEN  THE ORGANISATION
      OF NERVE TUBES  AND  THEIR VITAL PROPERTIES.
  It is well known that when the nerve tubes are examined in  a
very fresh state, their contents, the medulla, or white substance of 
39
Schwann, appear pellucid and homogeneous, and of a fluid con-
sistence ; but a kind of coagulation soon takes place in that me-
dulla, making it easily distinguishable from the tube itself, solid,
grumous and  much less transparent.   Water has the power of
producing  very quickly that kind of  coagulation of the white
substance of Schwann, and the more quickly the warmer it is.
   It was interesting to ascertain  whether a nerve-fibre keeps or
loses its vital properties when its contents have been transformed
by coagulation.   I have performed two series  of experiments in
order to solve this question; one on the motor nerves, the other
on the nerves of sensibility.
   1st. After having amputated the two limbs of a frog, I laid
bare a long portion of the sciatic nerve in both.  Half an hour
afterwards these  two  nerves were  still able to act  perfectly
well.   Then  a microscopical examination  of  some fibres  from
one of these nerves demonstrated that the coagulation of the
medulla had begun, but was not yet complete.  Ten minuteg
later the nerves were still capable of acting, and the microscope
showed that the  coagulation was complete.  A similar  experi-
ment repeated  a great many times  has  always furnished the
same result.
   2d.  After having divided the two sciatic nerves, not far from
the knee-joint, in a living frog, I have dipped the central part
of these nerves into  water.  After a few minutes, some fibres
taken from one of them were beginning to  coagulate; yet these
nerves possessed their sensibility. Ten minutes after, there was a
complete  coagulation  of the medulla, while the sensibility was
very little if at  all diminished.
   I  draw  from these facts the conclusion that nerve-fibres are
capable of acting nearly as well when their contents are coagu-
lated, as when they are still liquid.
   This result appears  to be important, inasmuch as  it contri-
butes to show that the  white substance of Schwann has not a great
part in nervous action.  Three reasons concur in demonstrating
that the  essential part, the truly active  one—that which pos-
sesses  the vital  properties—is  not  the   white  substance of
Schwann :
   1.  We see that the vital properties of the  nerve-fibres do not 
40
 appear altered, although there is a very material change in this
 substance when it coagulates.
   2.  If such a  change as that which takes place  in this  sub-
 stance when it coagulates, existed in  a part possessing the vital
 properties  belonging  to   nerves, there should certainly be  a
 movement  or a sensation accompanying it,  and yet there is none.
 This  material  change is certainly more considerable than the
 change effected by a  slight mechanical or galvanic  excitation,
 which is capable of producing a movement or a sensation.
   3.  The  microscope  has already proved  that the  white  sub-
 stance does not exist in all the nerve-fibres, and that it is want-
 ing, for instance, in the very fine fibres.
   Therefore if it be not the white substance of Schwann which
 is active in the nerves, and as it is not  the cylinder  axis which
 possesses the vital properties of the nerves, because it is wanting
 in many fibres, it  results  that it is the membranous layer, the
 paries of the nerve-tube,  to which these vital properties belong,
 unless there  is another substance, still unknown, and existing in
 the tubular canal of the nerve-fibre.

 XVI--ON THE PERSISTENCE OF LIFE  IN ANIMALS DEPRIVED OF
                THEIR MEDULLA OBLONGATA.*
   I. There is no part in the nervous  system considered as more
 essential to life than the medulla oblongata.  In the last few years
 many German physiologists  have  asserted that this nervous
 centre is the source of the rhythmical movements of the heart.
 Besides, an eminent physiologist maintains that in  the medulla
 oblongata a small part exists which is the  focus of vital  power.
 Moreover, it is certain that the medulla oblongata  has a great
 share in the respiratory movements.   Therefore it  seemed pro-
 bable that the ablation of  such an  organ,  even in  cold-blooded
 animals, ought  to be speedily followed by death.   Such is not,
 however, the result' of that  operation;  and in favorable condi-
 tions, the  batrachia,  for  instance,  can live  more  than four
months  after the loss of the medulla oblongata.  During all that
 time, these animals, in appearance remain in good health, and  I
 have observed in them the  existence of all the following func-
 tions and properties:

     * See the Bulletin de la Soc. Philomatique.  Paris, 1849, p. 117. 
41
   1.  The  circulation of  blood continues as  well  as in  un-
mutilated frogs.   The beatings of  the  heart  are at  first quick-
ened  generally during half an hour, an  hour  or  an  hour and a
half,  after  the operation; they then  return  to  their normal
rhythm, and they are found as regular and vigorous in frogs de-
prived  of their medulla oblongata, for several  days or even
several months, as  in  healthy frogs.   Sometimes, particularly
when the hemorrhage has been considerable, the beatings of the
heart become less  numerous and less energetic; then the animal
dies very quickly, but if it lives, the movements of the heart re-
sume  before long their normal rhythm and strength.
   2.  The pulsations of the four lymphatic hearts take place as in
healthy frogs.
   3.  Digestion seems to be carried on as well and as quickly in
frogs  without  medulla oblongata as in healthy frogs.   I have
ascertained  this fact by introducing pieces of earth-worms into
the stomach of these animals,  and by studying the changes pro-
duced in these aliments  during their passage along the digestive
canal.  Although very  slow,  chymous  transformation, absorp-
tion and the production of faeces took place.
   4.  The products  of the gastric, intestinal, biliary and pan-
creatic secretions being very useful, if not essential to digestion,
it is very probable that these  secretions  exist.
   5.  The urinary secretion and also the  production of cutaneous
and intestinal epithelium, are performed as usual.
   6.  The pulmonary respiration ceases,  but the cutaneous respi-
ration is continued.   The absorption of  poisons by the skin and
by the mucous membranes exists as in healthy frogs.
   7.  The reflex faculty is energetic, and so much so that the
frogs  deprived of  the medulla  oblongata can raise by a reflex
action, greater weights than healthy frogs.  As reflex movements
exist,   I need not  say  that  muscles  and  nerves have kept
their  vital  properties.  It is  frequently found that the spinal
cord,  especially in the rana  temporaria, becomes so excitable
that the slightest irritation of the skin is followed by tetanic
convulsions.
   8. The galvanic  current  of muscles  not only exists in frogs
deprived of  medulla oblongata, but appears to be stronger.
   From  these  facts  it  results clearly  that frogs, deprived of
                              4* 
42
their medulla oblongata, are in  full life.   It is so much so that
if they are compared  to  frogs possessing that  nervous  centre,
they resist etherisation longer, and also live  longer after the
ablation of the heart.
   II.  The greatest differences exist in the duration of life, after
the removal of the medulla oblongata, in  animals  of different
species, as will be  seen in  the  following table,  where the maxi-
mum duration of life is indicated in  sixty  different  species  of
animals:
  Classes.                 Species
          f Salamanders
Amphibia. ) Frogs  .
          / Toads  .
Reptilia.
Fishes.
Birds.
 ( Tortoises
 ) Snakes
 / Lizards
 f Eel
 / Pike, carp, tench, eel pout, barbel
 / Perch, gudgeon and others
 f Sparrowhawk (newly born)
 j Magpie          do.
J Sparrow         do.
 j Sparrow, yellowhammer,  linnet, pi-
   Duration of life.
More than 4 months.

4 to 5 weeks.
9 to 10 days.
6 to 7 days.
4 to 6 days.
6 days.
3 days.
25 to 40 hours.
21 minutes.
19 minutes.
17 minutes.
Mammals.*
              geon, fowl,  duck,  pintaw,  par-
              tridge, moor-hen, turtle-dove (adult) 2] to 3 minutes.
           ' Dormouse (during hybernation)     29 hours.
            Hedgehog       ditto             23 hours.
            Bull-dog (newly born)   .      .     46 minutes.
            Cat       ditto        .      .     41 minutes.
            Rabbit    ditto       .      .     34 minutes.
            Guinea-pig ditto        .      .     6 minutes.
            Dormouse and Hedgehog awaken in
              summer  ....     4 minutes.
           ^ Cat, rabbit,guinea-pig and dog ("adult) 3 to 3|  minutes.
   The preceding table shows that after the  removal of the me-
dulla oblongata,  in different  species  of animals,  the duration of
life may be reckoned by months for batrachia, by weeks for some
reptilia, by days  for other reptilia  and for  fishes, by hours for
  * Pulmonary insufflation  has  been  used only for the dormouse  and
hedgehog during hybernation. 
43
hybernating mammals, and by minutes for birds and non-hyber-
nating mammals.

  III. After the  removal of the medulla  oblongata, the most
remarkable differences in the duration  of life, in different indi-
viduals belonging to the same species, may occur in  consequence
of differences of temperature.   The  lower the temperature the
longer is the duration of life.   Thus, the  duration  of  life in
frogs may be reckoned by months when the temperature is be-
tween 32°  and  46° F., (0 and  8° Cs.); by weeks when it is
between  40°  and 55° F.  (5° and  13° Cs.);  by days when  it is
between  50°  and 65° F.  (10° and 18° Cs.)  by hours  when it is
between  65° and 72° F. (18° and 24°- Cs.); and by minutes when
it is between 86° and 105« F. (30° and 40° Cs.)
  In the other cold-blooded  vertebrata the  differences  in the
duration of life, after the removal of the medulla oblongata, are
not so great  as  in frogs, but the law is the same.   This  law
exists also for warm-blooded animals, so much so that  the differ-
ences existing between mammals of different ages and of differ.
ent species, are  to be attributed, in  part, to their differences of
temperature.
   IV. As  the principal  condition for a long duration of life
in  cold-blooded  vertebrata is a cold  atmosphere, and  as the
vital  phenomena taking  place in  these  animals are much dimi-
nished when  they are exposed to  a  low temperature,  some  phy-
siologists have supposed  that  the persistence  of life  for many
weeks or more, wras equivalent, as regards the sum of the  vital
phenomena, to a duration of some hours in  summer, when these
phenomena have a great activity.
  In  answer to this  objection I will at first  call  the reader's
attention to the  fact that, in batrachia, deprived of the medulla
oblongata, and exposed to the action of a low temperature, the
heart beating, on  an average,  35 times in  a  minute and life
lasting four months—i. e. 172,800 minutes, it follows that, during
that  time, the heart has more  than 6,000,000 pulsations.   In
summer, the  maximum duration  of life having been six hours—
i. e. 360 minutes, and the heart beating, on an average, 45 times
in a minute,  it results that, during that  life, the heart has  only
1,600 pulsations—a number which is to the  other as 1 is  to 375. 
44
    This comparison  shows how incorrect it is  to  suppose that in
 consequence of the diminution of the vital phenomena in cold wea-
 ther, a batrachian that lives several months does not  live more
 than another living  only several hours in summer.
    This opinion is also proved erroneous by the facts which I have
 already related, and which show that all the functions and vital
 properties existing in frogs deprived of their medulla oblongata,
 appear to be  as active as in unmutilated frogs.  No doubt that
 there is a notable difference between summer and winter as to the
 activity of vital phenomena in frogs, but if we suppose that these
 phenomena are in winter only the tenth of what  they are in
 summer, and if we consider, consequently, the duration of life in
 winter  as being only the tenth of what it is, we  shall  have,
 nevertheless, a duration in winter forty or fifty times as great as
 the duration in summer.
   V. Now I have to examine why, in summer, the  life of cold-
 blooded  vertebrata,  deprived of the medulla oblongata, is much
 shorter than in winter.
   The principal cause of  this difference is in the fact that the
 cutaneous respiration, (it  is known  that the pulmonary respira-
 tion does not  exist  in animals  deprived of the medulla  oblon-
 gata,) which is sufficient as long as the temperature  is  very low,
 becomes more and more insufficient, when the temperature be-
 comes more and more elevated.  So  that the same law  exists for
 the cold-blooded vertebrata deprived of their medulla oblongata,
 and for those which are  not mutilated.  The following experi-
 ments concur to demonstrate the correctness of this view:
   I have found that  frogs deprived  of their medulla oblongata
 live much longer when placed in  oxygen than in atmospheric air.
 I have made two series of experiments—one in June, 1847, the
 other in July, 1850.  In both series the  frogs were put imme-
 diately after the operation, under a receiver full of oxygen. They
 lived from eight to  fourteen  days  at a temperature  at which
life, in atmospheric air, is  always shorter than  six hours.  The
 temperature was  from  64° to 84° F. (18° to 29° Cs.)   These
frogs would have lived  longer  if the  quantity of oxygen had
been more considerable.
  By pulmonary insufflation I have  maintained life  in tortoises
deprived of the medulla oblongata, much longer  than  when in- 
45
 sufflation is not  used.   The  duration  of life  was 7,  12, 13
 and 17 days in four insufflated tortoises.   When death occurred
 in  these four  animals, they had  been left without insufflation
 more than  five or six  hours, and very  likely they would have
 lived longer had they  been insufflated  more  frequently.   In
 four non-insufflated tortoises life  lasted  3, 7, 19 and 23 hours.
 These comparative experiments were made in summer in a tem-
 perature varying  from 64° to 86° F. (18° to 30° Cs.)  The in-
 sufflated tortoises lived  longer  in summer than non-insufflated
 tortoises in  winter.
   From all  these facts it is  evident that in animals deprived of
 the medulla oblongata,  death is  principally  caused by insuffi-
 ciency of respiration.

 XVII--ON THE INFLUENCE OF THE TEMPERATURE OF A  WARM-
   BLOODED  ANIMAL UPON THE  DURATION OF  ITS LIFE WHEN IT
   IS ASPHYXIATED.
   One  of the  most positive facts in physiology is that every
 animal  needs  oxygen in order to  live.  But  if there is  a com-
 plete uniformity as to the necessity of oxygen for all animals,
 there is also the greatest variety between the different species as
 to the quantity of that  gas  which is necessary for the mainte-
 ance of life.  Very probably a great part of the physiological
 differences between different animals, comes from the difference
 in the quantity of oxygen absorbed by  their blood in a given
 time.  The  most important cause  of the differences existing be-
 tween cold and warm-blooded animals, and between young and
 adult animals, is to be found in the differences in the quantity
 of oxygen they absorb.
   It is very remarkable  that one  of the principal laws relative
 to the anatomical  differences existing  between the different spe-
 cies  of animals, appears to be also a law regulating their phy-
 siological differences.   In an anatomical point of view, a mam-
 mal, at  the different  periods  of its  development,  presents
 alternately the forms  of many different beings.   In a physiolo-
gical point of view, a corresponding transformation occurs for
the mammals.   They exhibit alternately  the  same phenomena
of life exhibited by many other different animals.  For instance,
before its birth, the  mode of breathing of a mammal is  the 
46
same  as  that of fishes.   The oxygen absorbed  by fishes exists
in a liquid ; the  oxygen absorbed by the mammal foetus exists
also in a liquid, which is the blood of the  mother.  In fishes
and also  in mammal foetuses, oxygen has to pass through many
membranes: in fishes,  through the mucous membrane  of  the
bronchise and  the  membrane of the  capillary vessels;  in  the
mammal  foetuses, through the membranes of the capillary vessels
of the maternal and the  foetal  placentas, and their  mucous
coverings.  After  birth young mammals have an  insufficient
power of breathing, and in this they are like the reptilia. They
are unable to absorb a sufficient  quantity of oxygen to resist
the influence of cold; and their power  of retaining life when
deprived of oxygen, is comparable to  that of the reptilia.
   This fact  has been well established by  the  experiments of
Buffon,  Boyle, Ens, Roose,  Haller,  Fontana,  Legallois,  and
more  particularly W. F. Edwards.  Nevertheless, these eminent
experimenters have left  many important questions  without so-
lution, some of which I will examine here.
   In  order to study the influence of temperature on the duration
of life in  asphyxiated  animals, W.  F. Edwards  dipped  into
water, at different  degrees  of temperature,  many animals of
different ages.  Unhappily he did not  take  notice  of the  tem-
perature of the  animals on which he experimented;  and we
will show that this circumstance is very important,  because the
degree of that temperature at the instant when asphyxia  begins,
has a considerable  influence on  the  duration of life.   Conse-
quently, to discover with exactitude the influence of the tempera-
ture  of  a  medium, on animals deprived of  breathing,  it  was
necessary to operate on animals at the same temperature.  This
has been done neither by Edwards nor by any other  physiologist.
   A priori it is  easy to acknowledge that the duration of life
in animals asphyxiated can be influenced by four capital  circum-
stances : 1st. The degree of the temperature of the animals;
2d. The degree of the temperature of the medium; 3d.  The
age of the  animals;  4th. Their species.
   Consequently four series of experiments were to be performed.
I have made them, and I propose to give here some of the results
I have obtained.  The remaining  shall  be detailed in a special
paper. 
47
I. Lnfluenee of the  Temperature of young u'arm-blooded animals
         on the length of their resistance to Asphyxia.
  Experiment  1. Nine rabbits of  the  same  brood  and aged
about two days, were dipped into water at 25° Cent. (77° Fahr.)
Two of these animals, No. 1 and No. 2, had  the  temperature
which they  generally have when they are  in their nest covered
by their mother.  The  others  had  been cooled by having been
exposed to the action of an atmosphere at 10° Cent. (50° Fahr.)
No. 3 and No.  4 had been exposed  for a  quarter of  an hour;
No. 5 and No.  6 for three quarters of an hour; and No. 7, No.
8 and No. 9 for an  hour and a half.  The results are represented
in the following table:
                            TABLE I.*
                                                    Mean
   Nos.             Temperature of Animals.   Duration of f.ife- Duration of Life-
12'

IS'}

23'
           35° to 36° Cent. (95 to 97° Fahr.)      10' 1
                    ditto       ditto           14' j
           29° to 30° Cent. (84° to 86° Fahr.      16' \
     4,              ditto       ditto           21' j
     5,     23° to 24° Cent. (74° to 75° Fahr.)      20' |
     6,              ditto       ditto              j
     7,     18° to 19° Cent. (65° to 06° Fahr.)      22' ^|
                    ditto       ditto           29' I     28'
                    ditto      ditto           33' J
   The one that  lived shortest (10',)  was nearly  at  369 Cent.
(97° Fahr.;) the one that lived the longest (33',) was nearly at
18° Cent. (65°  Fahr.)   The  difference of temperature  being
17Q or 18° Cent, (about 32°  Fahr.) the difference  as  to  the
duration  of life  was 23 minutes—that  is, nearly two minutes
for each diminution of three degrees Fahr.
   The same experiment  performed  on many breeds of rabbits,
has always given very nearly the  same results.
   These experiments prove that the temperature of  young rab-
bits has a decided influence upon the  duration of their life,
when they are deprived  of  breathing.   I  have ascertained that
the same thing takes place in cats, dogs, mice,  and many species
of birds.
   Experiment 2. I dipped into water  at the temperature of 25°
Cent. (77° Fahr.) three bull-dogs.
  * The existence of reflex  movements has been used  in this experiment
and in all the others as the proof of life. 
48
                            TABLE II.
        Nos.          Temperature of Animals.         Duration of Life.
         1,    .     38° Cent, (about 101° Fahr.)     .     15'
         2,    .     30    "         86    "       •     24'
         3,    .     22    "         77    "       .     47'
   Between No.  1 and No. 3  the difference  of temperature  was
16° Cent. (29°  Fahr.;) the difference in the duration of life was
thirty-two minutes—that is,  two minutes for each diminution of
one centigrade  degree  (nearly 2° Fahr.)
   Experiment  3. I put a  ligature  around  the trachea of four
cur-dogs of the same brood, and aged three  days.
                           TABLE III.
        Nos.         Temperature of Animals.         Duration of Life.
         1,    .     37° Cent, (about 99° Fahr.)      .     13'
         2,    .     28    "        83    "        .     19'
         3,    .    24    "        76    "        .     31'
         4,    .     19    <•        67    "        .     51'
   So that between the two extremes the difference as the dura-
tion of life, was 38 for 18 Cent, (about 32° Fahr.)
   Many other experiments on very young dogs gave very nearly
the same results.
   Experiment 4.  On five cats, of the same brood, and aged two
days, I put a ligature  around  the trachea, after having cooled
three of them.
                           TABLE IV.
                Temperature of the animals.        Duration     Mean
    Nos.                                     of.life.     duration.
     1,       36° Cents., (about 97° Fahr.)        21')
     2,       36   «     «    97   "           30 J        *
     3,       23 to 24 Cent., (74 to 76 Fahr.)      47 1
     4,       22 to 23 Cent., (72 to 75  Fahr.)      50 J        *
     5,       17  Cent., (about 63 Fahr.)                    53
  The temperature of the air air was then at 18^° Cents., ("65 Fahr.)
   Experiment 5.  On four  mice, probably aged  from three to
eight days,  I put  a  ligature  around the trachea after having
cooled three  of  them.
                            TABLE V.
       Nos.          Temperature of the animals.        Duration of life.
       1,          34° Cents., (about 94° Fahr.)       ID
       2,          27    »      «   81   "          14
       3,          22    «      «    72   «          10
       4,          18    "      "    65   "          14
   I have obtained analogous results in experimenting on birds. 
49
  Experiment 6.   On  seven  magpies, aged from four to eight
days, I put a ligature  around the  trachea, and opened widely
the thoraco-abdominal cavity.
                       TABLE  IV.
 Nos.        Temperature of the animals.
 1,       36° Cent., (about 97° Fahr.)
 2.       36    «    «   97    <«
 3,       32    «    «   97
 4,       31J   «    »   90    "
 5,       26    "    "   79    "
 6,       26    «    «   79
 7,       22    ««    «   72
 8,       20    «    «   68
 9,      ' 20    «    "   68
10,       18    »    «   65
11,       10    »    «   65
Duration
 of life.
 20')
 28 5
 26
 39
 12
 58

 65
 87
 82
103
 Mean
duration.

 24

 324

 50

 72

 76

 92
  Experiment 7.  On other  magpies I made the same experi-
ment, but without opening the thoraco-abdominal cavity, so that
asphyxia was much more complete.
TABLE VII.	
Temperature of the animals.	Duration of life
35° Cent., (95° Fahr.)	8'
30 « 86 »	15
24 « 76 «	27
19 " 67 "	39
Nos.
1,
9
3,
4,
   I have  obtained nearly the  same results  from  experiments
upon many sparrow-hawks, ravens and jays.
   All these facts  show how considerable is the influence of the
temperature of certain young animals and birds on the duration.
of their life when they are asphyxiated.

II. Differences in the length of the resistance to  asphyxia ac-
              cording to  the species of animals.
   In order to discover what is the influence of the species, I made
the following experiment.   I tied the trachea on twenty-two ani-
mals belonging to eleven  species, all of which were aged about
four or five days.  Their temperature had been cooled and they
were all at about 26° Cent., (79° Fahr.)  The temperature of
the air was 19° Cent. (67° Fahr.)
                              5 
50
 Nos.
 1,
 2
 3,
 4,
 5,
 6,
 7,
 8,
 9,
10,
H,
12,
13,
14,
15,
10,
17,
18,
19,
20,
21,
09
       TABLE VIII.
Species.          Duration of life.   Mean duration of life.
Rabbit
  do.
Guinea pig
    do.
Mouse
  do.
Dog
 do.
Cat
 do.
Sparrow
   do.
Pigeon
  do.
Jay
 do.
Raven
  do.
Sparrow Hawks
      do.
Mag-pie
  do.
18'
24
 6
 9
20 )
27 j
25 )
39 $
31
36

M
 5 I
 9 S
13 I
17 5
14 )
23 $
16 }
24 $
21'
n
23.
32
33£
10
15
m
20
  Now if we compare  birds to mammals, we  see that generally
mammals resist  asphyxia more than birds.  The two following
tables show the difference :
Guinea-pigs
Rabbits
'Mice
Dogs
Cats
III
  TABLE IX.
Mammals.
Average
21

32
33i

234
         TABLE X
           Birds.
Pigeons
Sparrows
Jays
Raven
Sparrow Hawks
Mag-pies
Average
10
15
18}
20*
21}

151
      Influence of the temperature of adult warm-blooded animals
       on the duration of life when they are asphyxiated.
  I have discovered that the degree of the temperature of adult
non-hybernating vertebrata has also a  great influence on their 
                             51

power of resisting asphyxia.  Dogs, cats, rabbits, guinea-pigs
and birds, are subject  to  the same law when they are  adult as
when they are very young.   The lower their temperature, the
longer they live when they are asphyxiated.   But although the
existence of this  law for adult vertebrata is beyond all doubt, it
is sometimes  very difficult to ascertain that existence.  It is not
easy to diminish the temperature of  a  non-hybernating adult
mammal, or that of  a bird, without  exhausting the nervous and
the muscular power of  the animal, and also without producing a
general and  considerable  perturbation.  The  action of a cold
bath, for  instance, so  powerfully excites  the vertebrata, that
sometimes  violent convulsions take place, and then  death may
occur in a  short time, even before the animal has lost 10° cent.
(18° Fahr.) of its temperature.  However,  some individuals may
be  cooled without being exhausted by convulsions.  I have ex-
perimented on a great  many  which were   in this  condition.
For more  than eight years, without intending to make experi-
ments on this subject, I have had the opportunity of stating, on
more than a  hundred adult rabbits or guinea-pigs,  used for other
researches, that, when their temperature is diminished, the dura-
tion of their life, when they are completely deprived of breathing,
is decidedly longer than in the normal state.  Whatever has been
the cause of the cooling, the effect has been the same.   In these
numerous  experiments, the  animal  heat has been  diminished,
either by  a  disease, by  a  poison, by an injury in the nervous
centres, by the immersion of  the animal  in melted ice, or by the
application of a layer of  oil, essence, or gelatine, to the whole
skin of the animal.
   The best mode of cooling a  non-hybernating warm-blooded
 animal is to  make the following experiment, in a room where the
 temperature of the air is  not far from freezing point.   I remove
 the superior part of the cranium of  a mammal or  of a bird, and
 afterwards cut the brain,  slice by slice, from the anterior to the
 posterior extremity.  After the ablation of the cerebrum and the
 cerebellum, the  animal is put on the floor,  where it is left per-
 fectly quiet  for an hour or two.  If the experiment is made on
 a rabbit or a guinea-pig,  the temperature of the animal then falls
 from 40°  Cent. (104* Fahr.) to  30° or 35° Cent.  (86 or 95° F.) 
52
A ligature being put around the trachea,  I find  that the animal
is then able to live generally from six to 8 or 12 minutes.
   The more the animal heat is diminished, the more, in general,
is the resistance to asphyxia,  except  in cases where cooling has
been produced too quickly.
   On four adult rabbits,  I  put a  ligature around the  trachea,
and have  obtained the following results :

                           , TABLE XI.  )
      Nob.        Temperature of the animals.        Duration of life.
       1,        39£° Cents., (103° Fahr.)           3d'
       2,        35     »     95    "              6
       3,        30|  (between 86 and 87 Fahr.)     10
       4,        25  Cents., (77 Fahr.)             14
   On three guinea-pigs I  put  a ligature around the trachea, and
found the following facts:
                           TABLE  XII. -
      Nos.       Temperature  of the animals.       Duration of life.
       1,        40° Cents.,  (104° Fahr.)            2f'
       2,         35    "    ' 95    «               5±
       3,         30    "     86    «              12
   The longest persistence of life, after the cessation of breathing
which I have found in adult non-hybernating animals,  has been
in a cat aged five months, and whose  temperature had been  di-
minished to 19°  Cent, (about 67° Fahr.)  in consequence of the
laying bare of the  abdominal  viscera,  and of fhe ablation of the
cerebrum  by small parts.
   I will say only a few words about  my experiments  on adult
birds.
   Two pigeons were dipped into melting ice.   In  one  of them,
whose temperature had fallen from  42" Cent.  (108° Fahr.) to
35° Cent. (95° Fahr.) life lasted six minutes after the ligature of
the trachea.   In the other,  life lasted nine minutes; its tempe-
rature had fallen  from 42° Cent. (108° Fahr.) to  30°  Cent
{$6° Fahr.)
   I have obtained  nearly  the  same results in  experimenting on
fowls and on ducks.
   Physicians are  generally astonished  at  seeing that men at-
tacked with cholera are able to live  almost without breathing.
My experiments show that the principal, if not  the  only cause 
53
of the power living with so deficient a respiration, is the diminu-
tion of temperature.  The same thing occurs in the last hour of
life  in many cases of diseases,  and particularly those of the
brain, of the respiratory organs, and in that  dreadful disease of
children called scleroma.
   It is easy to understand how a  considerable breathing becomes
less  and less necessary when the temperature of the  animals
under experiment is diminishing.
   Whatever  may be the function of oxygen, it is positive that
most of the chemical changes which take place in  the living ani-
mals  are  accompanied with  a consumption  of oxygen.   If so,
when these chemical changes are  diminished,  the consumption of
oxygen  ought to diminish.   Now, as  every diminution  of the
temperature of an animal  produces a proportionate diminution in
nearly all the acts of organic and animal life, and as  these acts
are all accompanied by chemical changes in which oxygen is
consumed, it follows that, when they diminish, the consumption of
oxygen  also  diminishes.
   In the act of  running, or in  a  rapid  walk, we  consume much
more oxygen than in a state of rest.  What we call rest is merely
a state of diminished activity; and when  the temperature  of a
mammal has  been cooled down, the activity of most of the func-
tions is much more  diminished than in the most complete rest. It
results from this fact, that when a warm blooded animal has lost a
notable  part  of its ordinary warmth, its consumption of oxygen
is  much less than in a state of rest.
   If the ligature of the trachea is made simultaneously on  two
adult mammals of the same species, one  of them being at its nor-
mal temperature, and the  other  at a temperature of 5°  Cent.
(9° Fahr.) lower, we observe that this last one lives six, seven or
eight minutes, and the other  from one  and a half to  three
minutes.   If we suppose the quantity of ox}rgen existing in the
lungs and in  the blood of  these two animals is precisely alike in
both ; and if we admit that death  occurs in asphyxia, either from
want  of oxygen or by an action of carbonic acid,  in  both  cases
these two animals ought to live a different length of time, because
the consumption of oxygen contained in blood and the produc-
tion of carbonic acid are  quicker in one  of  them than in  the
other.   This  explanation  is so true, that when movements  are 
                                          54

             excited in the cooled animal, after the beginning of asphyxia, it
             dies sooner than when it remains in rest.
                From the facts and reasonings which are related in this note
             I draw the following conclusions :
                1st. The  temperature of  newly-born warm-blooded  animals
             has a great influence on the duration  of their life when they  are
             asphyxiated.
                2d.  There are very  considerable differences in the duration of
             life in asphyxiated animals  of different species, even  when  the
             experiment is performed in the same medium, and  while their
             temperature is at the same degree.
                3. The degree of the temperature of adult warm-blooded  ani.
             mals has also a great influence on the duration of their life when
             they are asphyxiated.
                4th. The influence of  the animation of  the temperature of a
             warm-blooded animal on the duration  of  its life in  asphyxia,
             explains  the persistence of life  in  man,  in  cases  of cholera,
             scleroma, and of some other diseases, when respiration is much
             diminished.
             XVIII__ON THE CENTRAL SEAT  OF GENERAL  AND  OF  TACTILE
                SENSIBILITY, AND ON  THE VALUE OF CRIES  AS  MANIFESTA-
                TIONS  OF PAIN.*
                To determine where is the seat of perception and of volition is
             one of the greatest physiological questions.  Flourens  maintains
             that this seat is in the central lobes.   Many physiologists, among
             whom  are Bouillaud, Gerdy and Longet, have published papers
             against the doctrine  of  Flourens.   Their  only important argu-
             ment  is  that mammals deprived of their whole encephalon, ex-
             cept  the medulla  oblongata and the pons varolii,  continue  to
*            possess the faculty of perceiving sensations, and that the percep-
             tion of pain  is then manifested by cries and agitation.  When
             the encephalon, says Longet,f is so much  mutilated, in rabbits
             and dogs, that only  the  pons varolii and the  medulla  ob-
             longata remain, in  the cranial cavity,  these animals,  although
             they seem to be in a deep coma,  are  still  able to agitate them-
             selves, and  to cry plaintively, under the influence  of strong
             external irritations; but  if  a sufficiently deep alteration is made

                *  See Comptes Rendus de l'Acad. des Sciences, 1849. t. xxix. p. 672.
                f Traite de Physiol. Paris. 1850. t. ii, B. p. 38. 
55
in the pons varolii  there is  an immediate cessation of the  cries
and of the agitation ; it merely remains an  animal in  whom the
circulation, the  respiration and the other  nutritive functions
are momentarily accomplished.
   On cats, rabbits  and guinea-pigs, I have obtained a completely
different result  in performing  that experiment.  After I had re-
moved, slice after slice, and from forwards backwards, the whole
encephalon, except only the  medulla oblongata,   I have  found
that the  mutilated  animal,  not only is much agitated, but  cries
plaintively when it is pinched.   If the medulla oblongata is also
removed, the cries  cease, but the agitation still continues.
   According to  these experiments,  it is evident  that the  pons
varolii is not the only seat  of  sensibility, the centre of perception
of tactile impressions, as  Longet  calls  it,  and  that either the
medulla  oblongata  is the seat of general sensibility or the cries
do not prove that there is a perception.
   Longet considers that the pons varolii  is not only the centre of
perception for sensation of pain, but also for tactile  impressions.
As to the tactile sensations he does not give the slightest appear-
ance of proof.    Certainly neither the cries nor the agitation are
sufficient to authorize  the opinion that the animal  has felt a sen-
sation of tact.   If the existence of cries could prove that there
is a perception of a tactile  sensation, I should have to conclude
from my experiments that  the medulla oblongata  is the  seat of
the faculty of perception of tactile  sensations, for there are cries
after the removal of the whole encephalon except the medulla ob-
longata,  and  there are  no  more after the  removal of this  last
organ.   If, instead of drawing conclusions from the existence of
cries, we take notice  only of the  agitation, we  are  bound  to
conclude that the spinal cord is the  seat of the faculty of percep-
tion of tactile sensations, for after this organ has been separated
from the medulla oblongata, agitation takes place when a limb is
pinched.*
   Cries  and agitation may be attributed  to a property of the
nervous  centres, which is completely different from  the faculty of
perception of painful or tactile sensations.   That property is the
reflex  faculty of the true spinal marrow ;f it is  the property  of
  • This conclusion is maintained as true by Senac, Caldani. Kay; Legallois,
Paton, J. W. Arnold and many others.
  f As Dr. Marshall Hall calls it. 
56
 uniting, in co-ordinate movements isolated muscular contractions,*
 which is called by German physiologists the faculty of adaptation
 to an end.   That property manifests itself by movements similar to
 those executed  by unmutilated animals when they feel a  pain ;
 and it happens, sometimes, that these reflex movements are less
 disordered than the movements consecutive to a violent pain in
 an unmutilated animal.   The agitation of the animals deprived of
 all the parts of their encephalon is merely the result of  an action
 of the reflex faculty.
   The  cries also appear to exist only  in consequence  of  a re-
 flex action.   This appears to be difficult to be proved, and it will
 seem nearly impossible  to  admit that  cries  may be  produced
 by an animal that has felt no pain, or that has not had the will
 of crying.  We  may  consider  a cry as  a noise produced in
 the larynx, as many times a quick expiration is performed when
 the vocal cords are stretched.   Now as the tension of these cords
 and the expiration  is  produced  by muscular contractions, it is
 easy to understand that  these contractions are produced  by  a
 reflex action as  well as the contractions of the muscles of the
 limbs.
   For those who know that hiccup, coughing, sneezing,  vomiting
 and so forth, frequently are mere reflex phenomena, there ought
 to  be no difficulty in  admitting that crying is  a  pure  reflex
 action.
   If  we here use the expressive language  of Flourens, we  will
 say, that the medulla oblongata has the faculty of uniting  in a
 co-ordinate movement, the contractions of the expiratory muscles
 and that of  the tensor muscles of the glottis.
   From the facts and reasonings contained  in this  note I  will
 now draw the following conclusions:
   1st, That the experiment by which many physiologists  have
 endeavored to prove that the cerebral lobes are not the exclusive
seat of the perceptions, do not give such a proof.
   2d, That  animals can cry after the  removal  of the whole
encephalon,  except only  the medulla  oblongata.
   3d,  That the existence  of  cries cannot  prove  that  there is
a perception of pain, because cries result from muscular  contrac-
tions which  may be pure reflex actions.
  * That is the name given by Flourens more than 25 years ago. 
57
   4th, That there is no proof that the pons varolii is the centre
 of perceptions either of touch or of pain.
   5th, That if it is admitted that cries prove that there  is a
 perception of pain,  we  should have to  admit  that  the  medulla
 oblongata is also a centre for these perceptions.

 XIX--ON THE  MODE OF ACTION OF SOME OF THE MOST  ACTIVE
             POISONS  UPON THE NERVOUS  SYSTEM.
   Some of  the results of my experiments  on this subject  have
 already  been  published  in  the inaugural dissertation  of my
 learned friend and pupil, Dr.  F. W. Bonnefin, with whom I per-
 formed most of these experiments.*
   I intend to give here only  the results  of  my researches on the
 poisons which produce  convulsions.  For the sake  of  brevity I
 have  called them  convulsing poisons.    The  most  important
 among them  are: strychnine, brucine,  picrotoxine,  morphine,
 digitaline, cyanhydric  acid,  nicotine, cyanide  of mercury, sul-
 phide of carbon, chloride of barium, and oxalic acid.
   The principal questions which I have endeavored to solve are
 the following :
   1.  What  is the  part of the animal frame upon  which these
 poisons act in producing  convulsions ?
   2.  By what mode of action do they produce convulsions ?
   The parts of the body on which they could act are :__
   a.  The nervous centres.
   b.  The motor or centrifugal nerves.
   c.  The sensitive or centripetal nerves.
   d.  The muscles.
   Of course, the convulsing poisons  could  act upon these  four
 parts together, or upon two or three of them.
   Now, as to the mode of action,  these poisons could produce
 convulsions directly or indirectly.
   In  other words these  poisons might  act :—1. As excitants
 either of the muscles or of the nervous system,  and this is what
 I call a direct  action.   2.  As causes of increase of the vital
 powers of the muscles or of the nervous  system, so  that even a
 slight excitation of these parts is  able  to produce  convulsions,
and this is what I call an indirect action.
  * Rech. Experim. sur Taction convulsivante des principaux Poisons, in 4
 Paris,  1851. 
58
   The convulsing  poisons  do not appear to excite the  muscles
or any part of the nervous system, and consequently they do not
act directly.   They act  merely in increasing the vital powers of
the nervous system, so that a slight excitation of the skin or ano-
ther part where there exist nerves of sensation is sufficient to pro-
duce convulsions. Therefore these poisons act indirectly in the pro-
duction of convulsions.   They do not produce convulsions, they
merely act upon the nervous system, so as to render it capable of
producing  convulsions when it receives  an excitation.  They do
not excite the nervous system, and their mode of action is altoge-
ther different from that of the mechanical, physical, and chemical
excitations which  directly produce convulsions, when they  are
applied to the medulla oblongata, or to  the spinal cord.
   This mode  of action  was  already  known as regards strych-
nine.   Long ago  Mr. Magendie* found that animals  poisoned
by nux vomica, frequently remain without convulsions as long as
they are  left without  excitation, but  that fits  are immediately
produced when  they are  touched.  Since that time  Stannius,f
Van Deen,J Pickford,|| J. W. Arnold,§ Meyer, of Zurich,H Mar-
shall  Hall,** and  A. Barnard,-}-}- have  observed  many facts
proving  that strychnine does not  directly produce convulsions.
The following experiment, which I performed with the assistance
of Dr. Bonnefin, is still more demonstrative.
   I introduce a large dose of strychnine into the stomach of a frog,
after  the removal of its brain and of its medulla oblongata.  As
the voluntary  and the  respiratory movements  are then impossi-
ble, there is no spontaneous  movement at all, and if  the animal
is  left perfectly  quiet there  are no convulsions.    But as soon as
it  is excited, even by the slightest touch, tetanus  occurs.
   In  this case, it is evident that the convulsive fit is merel}7 a re-

  * Examen de Paction de quelques vegeiaux sur la Moelle epinieie.  Paris
1809, p. 7.
  t Mueller's  Archiv. 1837, p. 223.
  ^Trailes et decouvHttes sur la  Moelle epinieie, 1841. p. 123,
  || In Rorer und Urarderlich's Vieiteljahesclirift.  Bd. 2,  1843, p. 430.
  § Ueberdie verrichtunu; der Werzeln der Ruckenmarksnerven,  1844.
   ^[Schmidt's Jahrlmcher, 1847, No. 8.
  ** Comptes rendus de l'Acad. des Sciences, 1847, vol.24, p. 1054.
  ff Pioces verbaux de la Societe  Philoinatique, 1847, p.  71. 
59
flex act.   But why is there a tetanic contraction  instead of the
regular reflex movements ?  The reason is that the reflex faculty
is considerably increased.  This will be proved in a moment.
  Before giving  this demonstration, I must examine if there is
not also  an increase in the vital powers of the muscles and of the
motor nerves. There was no reason  to reject the supposition that
the convulsing poisons were capable of increasing simultaneously
the vital powers of the nervous  centres, of the nerves, and of the
muscles.  Consequently, I  was led to  perform the   following
experiments,  which prove :—1st,   that  these  poisons do not
increase the  vital powers of  the motor nerves  and of muscles  ;
2d, that they do  not act as direct excitants upon these organs.
  On young  cats, on birds, and  on reptiles, I removed the whole
portion of the spinal cord which supplies nerves to the posterior
limbs.   A   fewT  minutes  after, I  injected  into the  rectum a
solution  of a salt of strychnine.  Convulsions occurred only in
the  anterior parts of the  body, and when I  excited  either the
motor nerves or  the muscles  of the  posterior limbs, contrac-
tions were   produced  exactly as in animals not  poisoned, but
there was no appearance of convulsions.
   When  the  poison  was placed  directly on  muscles or  on
nerves, or when  it was  injected with  blood in a limb  separated
from the body,  there  was  no appearance either of an  exci-
tation, or of an increase in the  excitability of the muscles,  or of
the motor nerves.
   The experiments of Magendie, of Emmert,* and of Backer,f
have demonstrated that after a transverse section of the spinal
cord, between its two enlargements, convulsions may be produced
in the palsied limbs, when  the animal is poisoned with strychnine.
All  the physiologists who  have  performed this  experiment have
found it perfectly exact. Nevertheless, J. W. Arnold,J maintains
that the action is much less considerable  in the posterior limbs,
in that case, than when  the  spinal cord is uninjured and united
with the medulla  oblongata, and he concludes that the poison

  * Exper. de  efTectu venenorum veget. americ. in corpus animale, 1817.
  f Commentatio ad questionem  physio!., ab Acad. Rheno  traject. anno
 1828, propositam.
   |  Die lehre  von der Reflex-function.  Chap. ix. and x.  1842. 
60
acts much more on the  medulla oblongata than on the spinal
cord.
   Sometimes, as Arnold says, it occurs that the action of strych-
nine, in  mammalia and in  amphibia, is not so powerful in  the
palsied parts, after  the section  of the spinal  cord, as in  the
non-palsied limbs. As to mammalia, the reason of this difference
is the diminution in the quantity of blood  received by the part
of the spinal marrow separated  from  the  encephalon.  As  to
amphibia, it is easily seen  that immediately after the section of
their spinal cord, the reflex faculty in the part  separated  from
the encephalon is very weak, and if, then, strychnine is given to
the animal, it does not  act very strongly ;  but if the poison is
given two or three hours  after the section of the spinal  cord,
then the reflex faculty is very powerful and the poison  acts vio-
lently, and sometimes more than if the spinal cord was uninjured.
In birds, which, as I have  discovered, have constantly a power-
ful reflex faculty after the section of the spinal cord, strychnine
acts very energetically.
   Lately, Stannius and Cl. Bernard have supposed that strych-
nine, instead of acting  on  the spinal marrow, acted on the nerves
of sensibility, and more particularly on their termination in  the
skin.   They base this hypothesis on some experiments, of which
only one is important.   After the section  of the spinal cord, at
the brachial  enlargement, upon a  frog, the animal  is poisoned
with strychnine, and then convulsions  occur nearly at  each  vo-
luntary or respiratory movement.   But if  the sensitive roots  of
the spinal nerves are cut, the convulsions cease immediately.
   Now, it is evident that this fact  does not prove what Stannius
and Bernard have supposed ; because  it  may be explained  as
well by admitting that  convulsions  are produced only in conse-
quence of an increase  of  the reflex faculty of the spinal  cord,
as by the hypothesis of Stannius.
   Van Deen  * relates an  experiment which is in opposition to
the theory  of Stannius.  If we take a frog prepared exactly as
in the experiment  of this physiologist, we  see that  tetanus  oc-
curs when  the animal  is thrown  on  the floor.  In this case
tetanus is  produced, although the  sensitive roots are cut and
unable to act; therefore tetanus is a consequence of an increased
                       * Loco cit. p. 123. 
61
 vitality in the spinal cord itself.   But  this*experiment is not
 decisive, because sometimes  it  occurs that such  a mechanical
 excitation in frogs,  which  have not been  poisoned, produces
 tetanus.  Nevertheless I must say  that  the  tetanus in this last
 case is never so violent as in poisoned frogs.
   A better experiment  is  to  excite  slightly with a needle, the
 posterior columns of the spinal cord.   Then, tetanus constantly
 occurs in poisoned frogs, although the sensitive roots are divided,
 and it very rarely occurs in  frogs that are not poisoned.
   I have already published* the following experiments, which
 are  much more decisive  against the  hypothesis of Stannius:
   A ligature is put  around the  aorta of  a  frog, near its termi-
 nation in  the abdomen, and consequently the posterior limbs
 cease  to receive blood.  Then the frog is poisoned with strych-
 nine introduced into  its  mouth, and after a few minutes the
 convulsive phenomena take place.
   In this experiment  the nerves of the  posterior limbs do not
 receive strychnine, whilst the  spinal  cord receives it;  therefore
 convulsions are not  produced in consequence  of an  action of
 strychnine on the sensitive nerves of  the skin, as Stannius has
 supposed, but in consequence of its  action on the spinal  cord.
   Now, if we poison  a frog after having divided the spinal cord
 at the brachial enlargement, and  after  the section of all the
 small  arteries giving  blood  to  the  spinal  column, we see that
 convulsions do not take  place  in the posterior  limbs, although
 the reflex faculty is not  lost in  consequence of the cessation of
 the circulation in the spinal cord, and  that it remains for half an
 hour or a little more in summer, and about two hours in winter.
   In this experiment, blood  containing strychnine  reaches  the
 sensitive  nerves of the  posterior limbs, and  not  the  spinal
 cord, and there are  no convulsions; therefore it  is not  on the
 sensitive nerves that strychnine acts in  order to  produce con-
 vulsions.
   These two experiments are evidently decisive.  In the first, we
 see  that when blood containing  strychnine  reaches the  spinal
 cord,  and  not the   cutaneous  nerves, there are  convulsions;
 and in the second, we see that when  blood containing strychnine
reaches the sensitive  nerves and not the  spinal cord, there
              * Gaz. Mod. de Paris, 1849, p. 745.
                             6 
62
are no convulsions.  We must consequently draw from these ex-
periments these two conclusions:
   1. Strychnine does not act upon the sensitive nerves.
   2. Strychnine acts upon the spinal cord.
   Now, from all the facts  above related, two  other conclusions
are to  be drawn:
   1. Strychnine does not excite the nervous system; or, in other
words, strychnine does not produce convulsions directly.
   2. Strychnine increases the reflex faculty of the spinal cord,
and so produces convulsions indirectly.
   I do not intend to examine here  whether strychnine  kills  in
producing convulsions, or by another  action.  Nevertheless, I
will  say, that although  convulsions  are  sufficient  to kill  in
asphyxiating,  death, in  cases of poisoning  by strychnine, may
be also produced by another action of that poison.   I have seen
;mimals  in  which convulsions did  not take  place  at all, and
which have been killed by strychnine.
   The  other convulsing  poisons that I have  studied, appear to
act as strychnine, as to the production of convulsions.
   The same  experiments which I have related  as  regards
strychnine, have been performed with these poisons,  and I have
obtained the  same results.   Sometimes, nevertheless, I found
some differences; and, for instance, it  appears that the chloride
of barium is a direct exciter  of the  muscular fibres, and cyan-
hydric  and oxalic acids seem  also to be slight but direct exciters
of the  spinal cord.
   The  action  of the chloride  of barium is  very important, be-
cause that poison is an exciter of the muscular fibres, and not of
the nerves.  This fact proves that the muscular irritability  may
be put  in action without the intervention of the nerves.
   The  increase of the reflex  faculty, by the convulsing poisons,
is  a very important fact.   How is that increase produced ?  We
believe it takes place in consequence of an increase in the nutri-
tion  of the nervous  centres.  J. Mueller* is  of opinion  that
there is no substance able  to increase directly the vital proper-
ties of any  organ.   He says that nutrition alone is  able to pro-
duce such an effect.   I believe he is perfectly right, and I ad-
mit that the  mode of action of the convulsing poisons, in the
       * Manuel de Physiol., edited by Littre, 1851, t. i. p. 582. 
63
 production of convulsions, is  merely to increase nutrition in the
 nervous centres.  It is important for practitioners to know that
 mode of action.   The usefulness of strychnine in many cases of
 palsy, may be  explained very  easily by  that action.   I have
 frequently seen, in the wards  of the hospital la Charite at Paris,
 paralytics under  the  care of  Dr. Rayer,  taking  strychnine.
 Every day the reflex faculty was increasing in them  as  long as
 they took that substance; and  on  the contrary, when the use of
 that medicament was stopped, the reflex faculty began immediately
 to diminish, and in some patients it disappeared.   If strychnine
 was given anew, the reflex faculty was still increased.  These
 facts have been recorded with great care by my learned friend,
 Mr. Chareot.   I hope he will publish them.
   From all the facts narrated in this paper,-1 believe I am enti-
 tled to draw the following conclusions:
   1. The convulsing  poisons, more  particularly  strychnine,
 brucine, picrotoxine, cyanhydric acid, nicotine, morphine, cyanide
 of  mercury, sulphide  of carbon, digitaline,  oxalic acid, appear
 to produce convulsions, without acting either directly  or indi-
 rectly on the muscles or on the  motor or sensitive nerves.
   2.  Generally these poisons  do not appear to produce convul-
 sions in  acting directly on any part of the nervous centres.
   3. These poisons, in  producing  convulsions, act only on  the
 parts of the nervous system endowed with the reflex faculty.
  4. The mode of action of these poisons consists in the increase
 of the  nutrition of the nervous centres, by  which  excess  of
 nutrition the reflex faculty becomes much increased.

 XX--ON THE  CROSSED TRANSMISSION OF  IMPRESSIONS  IN  THE
                       SPINAL CORD.

  Numerous experiments which I have performed have proved
 to  the   numerous  physicians  and students,  who   have seen
 the most important of them,  that the impressions made on one
 side of  the body are transmitted to the sensorium by the oppo-
 site side  of the spinal cord.
  It is  known  that  Galen* performed two experiments, which

  *See:  De locis affectis, lib. iii. cap. xiv; or De anatomicis admonstru-
tionibus, lib. viii. sect. 6. 
64
have  been considered as demonstrating that there is  no crossed
action in the spinal cord.
   One of  these experiments of Galen consisted in the transver.
sal section of a lateral half of the spinal marrow.  After  this
operation the animal was paralyzed in all the  parts situated be-
hind the section, on the same side, so that the palsy was on the
right  side of the body when the right side of the spinal cord was
divided, and vice versa.
   The second experiment consisted  in a longitudinal  section on
the middle line of the spinal cord so as to separate into two late-
ral halves the part of that nervous centre supplying nerves to the
posterior limbs.  After this operation  the  animal was able to
walk.
   Galen, in these two experiments did not examine the state of
the sensibility.   He speaks merely of the voluntary movements.
Nevertheless his researches  were  considered  in this  century as
completely proving that there is  no crossing of action  in  the
spinal cord, either for sensibility or for voluntary movement.
   The following  experiments will prove  that there is a crossing
of action for sensibility in that organ :
   1st. If a lateral half (i. e. the posterior and the antero-lateral
columns  and the gray matter of one side of the spinal cord), is
divided transversely at the level of the tenth costal vertebra, on
a mammal, it is soon evident that the sensibility is much dimin-
ished  in the posterior limb opposite  to the side of the sections.
On the contrary the sensibility instead  of being lost  appears
much increased in the posterior limb on the side where  the  sec-
tion has been made.
   2d. If, instead of one transversal section of the spinal cord,
two, three, four  or many more are made on the same lateral half
of that organ, the same results are obtained.
   3d.  If,  instead  of mere  sections, a  removal  of a  part of a
lateral half of  the spinal cord, is effected, the same results  are
still obtained.   In performing this experiment a longitudinal
section, one inch in  length, from behind forward, is made  in the
median plane of the spinal marrow, and then two transversal sec-
tions on a lateral half are made at the extremities of  the  longi-
tudinal section, so that a part of the cord is completely separa-
ted from that organ and afterwards removed. 
65
  4th. If instead of dividing entirely a lateral half of the spi-
nal cord, a small part is left undivided towards the  centre  of
that organ, the posterior limb on the  same side becomes much
more sensible, but the posterior limb on the opposite side remains
very sensible and sometimes it appears more sensible than in the
normal state.
  5th. If in performing the section of a lateral half of the spi-
nal cord the instrument goes a little  too far and  divides also a
small portion of the other half, then the posterior limb on the
side of the  complete section is less sensible than in the  normal
state, and  the posterior limb of the opposite side, loses com-
pletely its sensibility.
   6th.  If the section of a lateral half of the spinal cord is made
at the level of the second or third  cervical vertebra, it is found
that the  sensibility becomes very quickly much  greater  in the
parts of the body on the  same  side  as the section, and  on the
contrary the parts on the  other  side becomes  evidently less sen-
sible.
   7th. If  after a section of a lateral half of the spinal cord  at
the level of the eleventh costal  vertebra, another section is per-
formed on the other side of  that organ, at the level of the sixth
costal vertebra, so that the  two lateral halves are  divided, then
sensibility in most  of the cases  is lost, on both  sides.   Some-
times  it retains a" very slight degree of sensibility, more  parti-
cularly in the posterior limb on  the  side where the spinal  cord
has been divided at the level of  the sixth costal vertebra.
   8th. If two sections of lateral halves are made as in the pre-
ceding experiment, but at a  greater distance, one from the other,
 on the right side for instance at the level of the twelfth costal
vertebra, and on the left  side in the  cervical region,  nearly  the
 same results are  obtained as to  the posterior  limbs, but  the sen-
 sibility is increased in the right anterior limb and it remains very
 evidently, but much diminished, in  the left anterior limb.
    9th. If a longitudinal  section is  made on the  part of  the
spinal  cord giving nerves to the posterior extremity, so as  to
 divide that part into two lateral halves, then it is found that sen-
 sibility is  completely lost in  the two  posterior limbs, although
 voluntary movements take place in them.
    10th. If a similar separation  of two lateral halves  of the spi-
                                 6* 
66
nal cord is madeon the whole part supplying nerves to the anterior
limbs, then it is found that sensibility is lost in both these limbs,
and that it is only slightly diminished in the posterior limbs.
   11th. If the same operation is done as  in the preceding expe-
riment, and afterwards if a transversal division is made  on one
of the lateral halves, in the place where it is separated from the
other, then it is found that the posterior limb on the  side of the
transversal section remains sensible, and that the other posterior
limb loses its sensibility.
   These experiments prove very clearly  that the  sensitive ner-
vous fibres are crossed  in the  spinal cord.   The 9th, 10th,  and
11th, demonstrate directly the crossing.   In these experiments
the crossed  fibres are all cut, and sensibility is lost.  This fact
appears to prove  that all  the sensitive fibres cross each other ;
but it  will be  easily understood  that  on  account of the  loss of
blood,  and of the general diminution of sensibility produced  by
the  excessive pain of  the  operation, if  there are some  fibres
which  remain  without crossing, they are insufficient to  give
sensations.
   As to the experiments consisting in transversal sections of a
lateral half, they prove  that sensibility is much diminished in the
side  of the  body opposite to  that of the section; consequently
they prove also that  there is   a crossing  of  a great  part of the
sensitive fibres.
   The fact that transmission of impressions  made on one side of
the  body takes place, at least for a great part, in the opposite
side  of the  spinal cord, is proved evidently by the eight first
experiments, but much more by the 7th and the 8th experiments
in which it is found that, after a section of a lateral half of the
3pinal cord, sensibility  remains on the same side,  and that it is
nearly entirely lost after a second section of the other  lateral
half in another place.
   If most of the nervous  sensitive  fibres  are  crossed  in the
spinal  cord, then it is not exact to admit that the crossed paraly-
sis of sensibility in cases of diseases  of  the brain, is explained
by the crossing of fibres which exists  in the pons Varolii and in
other parts of the encephalon.  Many opinions have been pro-
posed as regards  the place where the sensitive  nervous fibres
make their  crossing in the encephalon.   According  to some pa- 
67
thologists, this crossing takes place all along the medulla oblon-
gata, the pons Varolii,  tubercula  quadrigemina  and  the  crura
cerebri.  In all these organs there is  truly a crossing of fibres,
but we  do  not  know what are  these fibres.  Ch. Bell  believes
that the crossing of the sensitive fibres takes place in the poste-
rior surface of the medulla oblongata, in a great  part of the
length of the fourth ventricle.  Longet supposes that this cros-
sing exists at the anterior border of the pons Varolii, where the
two processi cerebelli ad testes cross each other.
   My experiments prove that if there  are some fibres coming
from the trunk and from the  limbs  which do not  effect  their
crossing in  the spinal cord itself, their number ought to be very
small.  Therefore the fibres  which are found crossed in the ence-
phalon are not  sensitive fibres  coming from the limbs and from
the trunk, as all physiologists have supposed they were.
   My  experiments  were  made  on many different  species;
 guinea-pigs, dogs,  cats, sheep, and rabbits.  In all the same re-
 sults were obtained.
    To  ascertain the  degree  of sensibility, I used various  modes
 of  excitation; mechanical, galvanic, physical,  (i.  e.  warmth
 and cold,)  and chemical.   I constantly compared  the degrees
 of sensibility in  the parts  of the body situated behind the in-
 jured portion of the spinal  cord, with the  anterior parts  of the
 body, and particularly with  the face. It is thus that I have been
 able to ascertain the existence of an increase or of a diminution
 in sensibility.
    Sometimes I have given  chloroform to animals having had a
 lateral half of the spinal cord divided  in the  cervical region.
 I  have found  that complete  loss of sensibility appeared  at
 first in the parts of the body opposite to the section of the spinal
 cord, the head and neck,  and at last in the parts of the  body be-
 hind the section of the cord, on the same side. This experiment,
 as well as'many others, prove undoubtedly that there is an increase
 of sensibility in these last parts.  I will try in another article to
 explain this hyperesthesia.
    I believe I am entitled to conclude from the facts above re-
 lated :
    1st. That most  of the  impressions made on one  side of  the
 body are transmitted to the sensorium by  the  opposite side of 
68
 the spinal cord,  so that  the impressions on the  left side of the
 body are transmitted by the right  side of  the spinal  cord, and
 vice versa.
   2d. That the assumed function of the crossing of  fibres in the
 pons Varolii, and the neighboring parts, does not belong to these
 fibres, but to the fibres of  the spinal cord, all along which  they
 cross each other.
 XXI.--ON MUSCULAR IRRITABILITY IN  PARALYZED LIMBS, AND ITS
                     SEMEIOLOGICAL VALUE.
   Marshall Hall has published many papers, in which he has tried to
 prove that the degree of muscular irritability in paralyzed parts may be
 used  as a means  of diagnosis between cerebral and spinal paralysis.
   He calls cerebral paralysis that in which the paralyzed part is de-
 prived of the action of the brain, but not entirely, or not in the least, of
 the influence  of the spinal cord.   On the contrary, he  calls spinal
 paralysis that in  which the palsied  part is altogether deprived of
 the action of both the brain and  the spinal  marrow.   The cause
 of the cerebral paralysis may be seated either in the  encephalon or
 the spinal cord; and the cause of the spinal paralysis may be seated
 either  in  the  spinal  cord or in the nerves.
  In the same individual  these  two  kinds  of paralysis may exist
 together.   Suppose a man in whotn the brachial  enlargement of
 the spinal cord is considerably softened, and consequently unable
 to act;  the upper  limbs then  have a spinal  paralysis, and the
 lower limbs, receiving their nerves from a healthy part of the spinal
 cord, have only a cerebral paralysis.
   According to Marshall Hall, the cerebral paralysis is attended by
 augmented muscular irritability, and the spinal patalysis  is attended
 by diminished irritability.  He bases  this opinion on the following
 experiments, and on some clinical observations.
  On six frogs he divided the spinal  marrow immediately below
the origin of the brachial nerves ; and he removed a portion of the
ischiatic  nerve of the right posterior  extremity.  He had  imme-
 diately, or more remotely, the following interesting phenomena  :
  1st.  The  anterior extremities alone were  moved spontaneously;
both posterior  extremities  remaining  entirely motionless when the
animal, placed on its back, made ineffectual efforts  to  turn on  the
abdomen. 
69
   2d.  Although perfectly paralytic in regard to spontaneous motion,
the left posterior extremity, that still  in connexion with the  spinal
marrow, moved very energetically  when stimulated by pinching the
toes with the forceps.
   3d.  The right posterior extremity, or that of which the ischiatic
neive was divided, was entirely paralytic, both in reference to spon-
taneous and excited motions.
   4th.  After the lapse  of several  weeks, whilst  the  muscular irri-
tability of the left posterior extremity was gradually augmented, that
of the right was gradually diminished,—phenomena observed when
the  animal was placed in water  through which a slight galvanic
shock  was passed accurately in the direction of the mesial plane.
   5th.  Strychnine being now administered, the anterior extremities
and the left posterior extremity, or that still in connexion with the
spinal marrow, became  affected with  tetanus ; but the  right  poste-
rior extremity,  or that severed from all nervous connexion with the
spinal  marrow, remained perfectly placid.
   6th.  Lastly, the difference in the degree of irritability in the mus-
cular fibre of the two limbs was observed, when these were entirely
separated from the rest  of the animal.
   After this exposition  of the results  of his experiments, Marshall
Hall adds : " In a word, the muscles  of the limb paralyzed  by its
separation from both  cerebrum and spinal  marrow, had lost their
irritability ;  whilst thoseof  the limb separated from its connexion
with the cerebrum only, but left in connexion with the spinal mar-
row, not only retained their irritability, but probably possessed it in
an augmented  degree.*
   It is easy to prove that Marshall Hall has been  completely mis-
led by his experiments.
   It is well known that the more  a muscle  is excited, the  more it
contracts.  As the degree of irritability is judged  by the degree of
the contraction, it follows that to know what is the degree of mus-
cular irritability we ought to apply the same excitation  to the mus-
cles we desire to compare.  In his experiments with galvanism and
with strychnine, Marshall  Hall has not done  so.   He  has applied

  ' On  the diseases and  derangements of the  nervous system.  1841, p.
215. 
70
 galvanism, so as  to excite much more the muscles of the left side
 united with the spinal cord, than those of the right side.
   The muscles of the left side were excited :
   1st. Directly by the galvanic current.
   2d. In consequence of the  excitation of the motor nerves.
   3d. In consequence of the excitation or the spinal  cord, directly
 by the galvanic  current,  and secondarily in consequence of. the
 excitation of the  sensitive nerves.
   So that the muscles on that side  were  moved  not only by the
 direct excitation on them, but also by a reflex  action,  and in conse-
 quence of the direct excitation of the spinal cord.
   As to  the muscles of the right side, they were  only excited by
 the small part of the galvanic current passing in them.   During the
 first, and perhaps the  second and the third week after the section of
 the ischiatic nerve, the muscles were also slightly excited by the
 motor fibres of that nerve,  but after that time these fibres had lost
 their vital property,  and  were  unable  to excite  a contraction in
 muscles.
   From  this  analysis  it results clearly that the mode of comparison
 of the two limbs, by the passage of a galvanic current, as it has
 been  employed by Marshall Hall,  could  not decide  in which side
 the muscles were  more irritable.
   The use of strychnine, also, could decide  nothing in this ques-
 tion, because,  as I have proved in a former article,  this poison is not
 able to act upon muscles.   It acts only on the nervous centres, and
 especially on the spinal cord.   Therefore, the production of tetanus
 in one limb and not in the other,  in the  experiment  of  Marshall
 Hall, proves nothing at all as to the degree of muscular irritability.
   To know what is that degree, it is necessary to  separate the two
 limbs from the trunk,  and then to excite directly the muscles. Mar-
shall Hall has  made this experiment, but  he says nothing about the
 circumstances   under  which it  was  performed, and these  circum-
stances were, as it will be shown, extremely important.
   In  my experiments, instead of dividing only the ischiatic nerve,
I divided the  four nerves going to one of the posterior  limbs,  of
many frogs, in whom  the spinal cord was divided  immediately
behind the roots of the brachial nerves.
  I have found on the separated limbs of these fro°\s : 
71
  1st.  That, at first, the muscular irritability  was greater in  the
limb which had been deprived of the action of the spinal cord and
of the  brain, than  in the limb deprived only of the action of  the
brain.
  2d.  That, at a variable time after  the  operation, the irritability
was at the same degree in the two limbs.
  3d.  That, at last, the irritability became greater  in the limb only
deprived of the action  of the brain, than in the  other.*
   The  differences  in  the  degree  of  irritability  have  been
observed : 1st. By the degree of the  contraction under the influence
of the  same excitation; 2d. By the duration of irritability.
   I have found that during a time, varying much according to sea-
 sons,  and to many other  circumstances, the  muscular irritability
increases in the two posterior limbs  in  a  frog  operated upon as I
 have described, and that the increase was more considerable in the
 limb where  the nerves were divided than in the other.
   If we compare two frogs, one operated on as before, and another
 having only had  a  division of all the nerves  on one of the pos-
 terior limbs, we find, a few days after the operation, that  in the
 four limbs separated from the body there are great differences as
 to the degree and the duration of muscular irritability :  1st.  The
 three paralized limbs have a greater irritability  than the one not
 at all paralyzed.   From  the three  paralyzed limbs  the  two in
 which the nerves have been divided have both  the  same degree
 of  irritability, and more  than the limb in which there was only
 what  Marshall Hall calls  a cerebral paralysis.   2d. The  irrita-
 bility has lasted  longer in the two limbs in which the nerves had
 been  cut, than in the two other limbs;  and from these  two,  that
 in  which there  was a cerebral paralysis has  remained  longer
  irritable.
    If  we examine the irritability in the posterior limbs of two
  frogs, operated on as aforesaid, for ten, twelve, or  fifteen days,
  then  we find that it is nearly at  the same  degree  in  the three
  paralyzed  limbs, and  greater  there  than in the non-paralyzed
  limb.
    * There  is,  in these experiments,  a cause of error, arising from the
  existence on one side,  and the absence, or, at least, a diminution in the
  other, of the vital power of tho motor nerves ; but the difference is trifling
  when the nerves are divided very near their entrance in the muscles. 
72
  If the comparison is made four or five weeks after the opera-
tion, then the non-paralyzed limb has a greater  irritability than
the three paralyzed, and, from these three, the one deprived only
of the  cerebral action has  a greater irritability than the two
others.
  The same experiments made on other animals than frogs, i. e.
on guinea-pigs and rabbits,  have given like results.  I shall pub-
lish the details of these last  experiments  in  a special paper, in
which I intend to examine the value of  the clinical observations
of Marshall  Hall,  R. B.  Todd, Duchenne  de  Boulogne, and
others.   I will merely  state  here, that in many cases it is almost
impossible to know what is  the difference in the degree of mus-
cular irritability in a paralyzed  limb, compared with a healthy
limb, in a living man or animal.   Galvanism and strychnine can-
not give us any exact notion in  this respect.  I ought to  add,
that if we could know  what  is the relative degree of irritability
in a  paralyzed limb, we could not make use of  that knowledge
for  the diagnosis  of the seat of the  alteration producing the
paralysis.  On the other side, we do  not want to know what  is
the degree of irritability in  order to establish such  a diagnosis.
It will be, almost constantly, easy to know whether a paralysis is
a cerebral or a spinal  one.    The existence of reflex actions  in
the paralyzed parts, is sufficient  to prove that there is a cerebral
paralysis, and the absence or the slight degree  of these actions
will prove that there is a spinal paralysis.
   The  following  conclusions may  be  drawn  from the facts
above related, and from others that I have not yet published.
  1st. The degree  of  muscular   irritability in paralyzed parts,
becomes rapidly greater than in the healthy parts,  but, after a
variable length of  time, it diminishes, and, as it is well known,
it may disappear.
  2d. The muscles deprived of the action of both the brain and
the spinal marrow, become rapidly more irritable than  the mus-
cles deprived only of the action of the brain, but, after a certain
time, there is also in them a more rapid diminution of irritability
than in the others.
   3d.  It appears  certain that  the  muscular irritability never 
73
disappears completely in  parts  deprived only  of the cerebral
action. *
   4th. In certain  cases  of paralysis, and more particularly of
the face, as after the removal of a large part of  the facial nerve,
the muscular irritability may exist for years, at least  in rabbits
and other  animals.
   5th. It  is very difficult,  and sometimes almost impossible, to
know the relative degree of muscular irritability in healthy parts
compared  with paralyzed parts,  and such a knowledge could not
be of a great semeiological value.
   6th. The existence or the absence of reflex actions as a means
of diagnosis between the cerebral and the spinal paralysis, has
a  much  greater  value  than  the  degree of  muscular  irrita-
bility.
XXII.—ON  THE  INCREASE OF  ANIMAL  HEAT  AFTER INJURIES
                   OF THE NERVOUS SYSTEM.
   In another part of  this seriesf I have endeavored to prove
that the local increase of  temperature following the  section of
the sympathetic nerve, is the result of  paralysis of  the  blood-
vessels.   I will now relate  some other cases  in which  a local
increase of temperature takes  place after  various  other inju-
ries of the nervous  system,  and  apparently in  consequence of
the same cause.
   It was known, long ago, that an injury to the nervous system
might be  followed by a  partial or even  a  general elevation of
animal heat.  Sir B. Brodie says,t Mr. Chossat has published an
account  of some experiments  on animals,  in  which he found
 that the  division  of the superior portion  of the spinal cord
 produced  a  remarkable evolution of animal heat, so that it was
 raised much above the natural standard.  I have made  cxperi-

   * I have  had a pigeon on which nearly an inch of the costal part of  the
spinal cord had heen remove,!, and on which the muscular irritability in
 the posterior limbs, and a very great reflex power, have existed as long as
 I  have taken care of it, /. e. more than  twenty-seven months. I ought t»
nav that there has been no re-union of the separated  parts of the spinal
 cord.
   | Medical Examiner,  August 1853, p. 489.
   J Medico-Chirurg. Transactions, 1837. Vol. xx., p. 132. 
74
ments similar to those of Mr. Chossat, and have met with similar
results.   I have also seen several cases in  which an  accidental
injury of the spinal  cord has produced  the same  effect.   The
most remarkable of  them was that of a man who was admitted
into St. George's Hospital, in whom there was a forcible separa-
tion of  the fifth and sixth  cervical vertebrae, attended with an
effusion  of  blood within the theca vertebralis, and  laceration of
the lower part of the cervical portion of the spinal  cord.   Res-
piration was performed by the  diaphragm only, and,  of course,
in a very  imperfect  manner.   The patient died at the end of
twenty-two hours; and, for some  time previous to  his death,
he breathed at very long intervals, the pulse  being  weak  and
the countenance livid.   At last there  were  not more  than five
or six  inspirations in  a minute.   Nevertheless,  when  the  ball
of  a  thermometer  was  placed between  the  scrotum  and the
thigh,  the  mercury rose  to  111°   of   Fahrenheit's  scale.
Immediately after death, the temperature was examined in the
same manner,  and found to be still the same.
  Brodie was mistaken as regards the experiments  of  Chossat.
Instead  of  finding an increase in  the animal heat after  the sec-
tion of  the inferior  portion of  the  spinal cord,  Chossat found
a considerable diminution in the  temperature  of dogs.   But in
two cases,  where  the  spinal  cord was  divided at  about  the
level  of the last dorsal vertebra,  in dogs, Chossat* found an
increase in the animal heat.   In  one  of these  experiments, the
increase was from 41°.1 to 41°.5  Cents.,  (105°.98 to 106°.7
Fahr.)  In  the  other, the increase  was  from 41° 1 to  4°° 9
Cs., (105°.98  to 109°.6.)
  Dr.  Macartneyf   found  an increase in  the temperature  of
parts paralyzed  in consequence of  the division of their nerve.
II.  Nasse,J who made many experiments on this  subject, some-
times observed  an   elevation in  the temperature  of  the pa-
ralyzed  parts  after the division  of the sciatic nerve,  or   after
the partial  destruction of the spinal cord.

  * Mem. sur 1' influence du gyst, nerv.  sur la chal. anim.  These de Puis
No. 126.—1820, p. 35.   Exps. xxiii and xxiv.
  f Treatise on Inflammation, 1838, p. 13.
  j Yutersurchunger zur Physiol, und  Pathol., 1S39, v. ii., p. 190. 
75
    In more  than twenty  experiments,  I only once  found  an
 increase in the temperature of the leg of a guinea-pig, after the
 section of the sciatic nerve.  This  increase lasted  about two
 or three days after the operation, and it was of two degrees Fahr.
    After a complete transversal section of the spinal cord in the
 lumbar region,  in  birds  and mammals,  I  found, repeatedly,
 an increase of one, two or three degrees Fahr. in the temperature
 of the paralyzed parts.   I ascertained  that  it is not in conse-
 quence of an increase of  the general  temperature of the animal
 that such an  increase exists.  It  is to be  found only in the
 paralyzed parts.
   I never found any increase  of  temperature after a complete
 transversal section of the spinal cord,  either in the cervical or in
 the dorsal region.
   After  a section of a lateral  half  of the  spinal cord, at the
 level of one of the three or four last  dorsal vertebrae,  I have
 almost constantly found  an  increase in the temperature  of
 the posterior limb on the  side of the section.   The elevation
 varied from  one to four degrees Fahr.  On the contrary, there
 was  a diminution of from one to five degrees  Fabr.  in  the
 temperature of the other leg.  In some cases, in consequence of
 the increase of temperature on one side and its diminution on
 the other side, I  found  a difference of six or seven degrees
 Fahr. in  the temperature  of the two limbs.   It is very remark-
 able  that, together with  the  increase of temperature  in one
 limb, there is an augmentation of sensibility, and with  the di-
 minution of  temperature in the other limb, there is also  a dimi-
 nution of sensibility.
   Sinca the  publication of the results  of my experiments on the
 sympathetic  nerve, I  have performed them many other times,
 and I have found that the result is  not  so  constant as  Dr. A.
 Barnard and myself had admitted.  In some  rabbits there  was
 no  decided increase in the vascularization and  in the tempe-
 rature of the face.   I ought to say that, in these cases, the two
 ears were already warm, and very vascular before the operation.
 I have found, also, that generally  in very cold weather the ex-
 tremity of the ear of rabbits,  on the side of the section of the
sympathetic  nerve, remains cold.
  From my experiments and from the observations and experi- 
76
ments of Brodie, Chossat, H. Nasse and Macartney, it results
that the following opinion of Dr. Cl. Bernard is incorrect.   He
says :   " It is known  that  injuries of the  cerebro-spinal ner-
vous system constantly produce a  total  or a partial diminu-
tion in the temperature of animals, either when a nerve has been
divided or when  the injury is made on the nervous  centres."*
He says also that an injury of the sympathetic nerve produces
a very rapid increase of temperature; so that  the sympathetic
nerve and the cerebro-spinal nervous system are considered by
Dr. Bernard as completely different, one  from the other,  as to
the influence on animal heat when  they are  injured.  The one
should increase and the other diminish animal heat.
  The truth is that these two effects—increase and diminution—
may exist after an injury of either the sympathetic or the  cere-
bro-spinal nervous system ;f and, in both cases, the increase may
exist, at first, and be followed by a diminution.
  Before pointing out the co-existence of certain facts with the
increase or diminution of animal heat, I think it necessary to es-
tablish a distinction between the cases of increase of animal heat
after injuries of the nervous system.
  In some cases (as those  related by Brodie) there has been an
increase of temperature above the natural standard  of  animal
heat.   These  are very extraordinary and  very rare  cases, and
it  is not my intention to attempt to  explain them here.  In the
cases, the degree of temperature, although increased in some other
paralyzed parts, has not been above  the normal degree of blood
heat.  This is the only kind of increase of animal heat that I
have observed,  and this I will attempt to explain.  -
   I have found  that,—ceteris paribus,—the more the arteries
and capillaries are dilated, the higher is the degree of tempera-
ture.  This law is proved by the following facts:
   1st.  In  all  the cases of paralysis  (from  whatever cause)
where I have  found a diminution in the degree of temperature
of  a paralyzed part, the arteries and capillaries were evidently
much contracted.
   2d.  In the cases where the temperature was normal, the blood-
vessels were of their natural size.
           ♦Gaz.  Medic, de Paris, Vol. 7, No. 14, p. 227.
            t Vide : Chossat; loco cit., pp. 41-46. 
77
  3d. In the cases where the temperature was increased, I have
constantly found the arteries and capillaries enlarged.
  4th. In some cases, I have found the same changes occurring
in the temperature and in the blood-vessels.   The  temperature
at first  was greater than usual  and  the blood-vessels  dilated ;
afterwards both the temperature and blood-vessels became natu-
ral ; and, at last, the temperature becoming  lower than usual,
the size of the blood-vessels became smaller.
  I  need not  say that the changes occurring  in paralyzed
parts in accordance with the size of  the blood-vessels  were the
results of the differences in the amount of blood passing in these
parts.
  Now, it will be asked how, in certain  cases of palsy, the size
of the  blood-vessels is larger than usual, and smaller in other
cases.   I cannot explain how it is so, but I can assert  that it is
a fact.
  From the facts and reasonings related in this article, I draw
the following conclusions :
  1st.  An  injury of the  nervous system may produce  in the
parts, which then become paralyzed,  either an increase or dimi-
nution of temperature.
   2d. The  sympathetic nerve  and  the  cerebro-spinal nervous
system appear  not to be different one  from  the other, in this
respect.
'   3d. The degree  of temperature of  paralyzed parts depends  on
the quantity of blood they receive ;  and  this  quantity varies ac-
cording to  the size of the arteries and capillaries of these parts.
   4th. It  is a fact, hitherto unexplained, that  the arteries and
 capillaries may  be either  dilated, normal, or contracted in para-
 lyzed parts.
 XXIII__CAUSE  OF THE STOPPING OF THE HEART'S  MOVEMENTS,
   PRODUCED BY AN EXCITATION OF THE  MEDULLA OBLONGATA OR
   THE PAR VAGUM.
   E. II. and E. Weber have discovered a singular fact, hitherto
 unexplained.  When the par vagum  or  the medulla oblongata is
 excited by a  powerful electro-magnetic current, in  a  living
 animal, the movements of the heart are  suddenly stopped.  This 
78
 should be what is known for all motor nerves and muscles, if the
 cessation of the movements of the heart was the result of  a per-
 manent contraction.   But the heart is not at all contracted, and,
 on the contrary, it remains perfectly placid.
    This is entirely different from what we know  to be the case
 for other muscles.
    I have found that a violent mechanical excitation of the me-
 dulla oblongata produces also the  same stopping of the heart's
 action.
    Is the heart in a state of rest in consequence of a loss  of its
 irritability or of an interruption of the excitation »ecessary to
 its action ?   The following fact  proves that this second opinion
 is the right one.  When the heart  is stopped, every direct exci-
 tation upon it produces some beatings,  and then,  its irritability
 appears to be entire.   The stopping, consequently, depends on
 the absence of excitation.
    The cause exciting the heart to beat is in the  blood  contained
 in the capillaries of this organ, as I will try to prove in another
 article.   Now, if we suppose that the galvanization of the par
 vagum produces a complete constriction of the capillaries of the
 heart, it is  easy to understand why the heart is stopped:  it is
 because the excitation  cannot take  place on account of the ex-
 pulsion of the blood from the eapillaries.
   It will  be asked on what ground we base the supposition  that
 the capillaries are so contracted  that they prevent entirely, or
 nearly so, the passage of the blood.   I will answer :
   1st. That it is known that a galvanization of certain nerves
 (and I have discovered that it is so with the capillaries of the face
 and ear when  the  sympathetic  nerve is  galvanized) may  pro-
 duce a considerable constriction of capillaries.
   2d.  That it is known  that the  nerves of the heart are distri-
 buted much more to its blood-vessels than to its muscular tissue.
   3d. That, hj our supposition, we place the fact of the stopping of
the heart's movements among the well known facts, that an excita-
tion of a  molar nerve  produces a contraction of the muscles to
which it is distributed ; and, therefore, we are not obliged to admit
that an excitation of a nerve is able to produce directly either a
contraction of or the cessation of existing contractions.
  There is a practical consequence to be drawn from the fact that 
79
in the case of an excitation of the medulla oblongata, the stopping
of the heart is not produced by a loss of irritability of this organ.
   Many  cases of syncope are produced  by a stopping of the
heart's movements in consequence of the influence of an emotion
on  the  medulla oblongata.    In  these cases  it would  be of
very great importance to excite directly the beatings of the heart,
either by  compression of the chest or  by  an application of  gal-
vanism.
   We ought to say that galvanism applied directly to  the heart
increases its beatings instead of diminishing them.

XXIV.—ON A SINGULAR DISTURBANCE IN THE VOLUNTARY  MOVE-
   MENTS, APPARENTLY PRODUCED BY AN ACTION OF ATMOSPHERIC
   AIR ON THE GRAY MATTER OF THE SPINAL CORD, IN BIRDS.

   Some years ago I discovered that after  the removal  of a large
quantity of the gray matter that exists in  birds, on the posterior
surface  of the spinal cord, in the lumbar region, a great disturb-
ance took place in the  voluntary movements.  I attributed this
disturbance  to the  loss of  gray  matter.   I have found, three
or four  months since, that  the same disturbance existed in the
voluntary movements after I had merely laid  bare  the  gray
matter,  and immediately after it had been exposed to the action
of air.
   I am perfectly satisfied  that it is not  in consequence of a
mechanical excitation of the spinal cord, accidentally  produced
during the operation of the removal of the bones and membranes,
that this disorder takes place.
   When the  spinal cord is laid bare elsewhere than in the region
of the lumbar enlargement—that is, in  any place where the white
substance covers completely the gray matter—there is no disturb-
ance produced in the voluntary movements.
   That  disturbance  very much  resembles the  so-called  tituba-
tion which exists  after either the removal  of  the  cerebellum or
the section of muscles  of the posterior part  of  the  neck.   At
each movement of progression,  the animal tends to fall  either
forwards, backwards,  or laterally.   It  does not fall  completely,
but is obliged, in order to avoid falling, to  make use of  its wings,
its tail and its beak. 
80
            XXV.—ON  THE TREATMENT OF EPILEPSY.
   I have made numerous experiments with regard to the treatment
 of this dreadful affection, and I intend to publish them, in extenso,
 when some points that are still obscure have become clear to my
 mind. Here I will merely relate some of the most important results
 of my researches. As I have had the  opportunity during  the last
 three or four years of observing every day a great many  animals
 (more than a hundred) which had a convulsive affection resembling
 epilepsy very much, I  have been able to discover some very in-
 teresting facts, among which are the following :
   1st. For each epileptic animal, the number  of  fits, in a given
 time, is generally in a'direct proportion with  the quantity of food
 taken.
   2d.  There is an inverse proportion between the amount of exer-
 cise and the number of fits.
   3d. Cauterisation of the mucous membrane  of the larynx  is
 able either to cure or to relieve these epileptic  animals.
   The convulsive  affection existing in almost  all  these animals
 was the consequence of a transversal  section of a lateral half of
 the spinal cord, in the  dorsal or in the lumbar region.
   I have  already published the results  of my experiments on
 epilepsy, in my lectures  before large  classes of Physicians and
 Medical students, both in France in 1851 and in this country in
 1852.
   These results are in perfect accordance with the views of Dr.
 Marshall Hall in  relation to epilepsy.  As the views  of this emi-
 nent biologist are generally known,  I need not expose them, and
 I will merely remind my readers of the three following points:
   1st. The first muscles that contract spasmodically in  almost
 all, if not in all, the cases of epileptic  fits, are those of the larynx
 and the neck:  2d, spasm of the glottis  taking place then,
 produces suffocation, in  consequence  of which convulsions are
 produced in the trunk and  the limbs;  3d,  tracheotomy may pre-
 vent these convulsions by preventing suffocation, and it is known
 that in some  cases tracheotomy has  cured epilepsy.
   It has been objected to Marshall  Hall that in cases of  poison-
ing by strychnine, convulsions take place  even when a tracheal
tube renders respiration  perfectly free.  This objection  has no 
81
value, because  the state of the spinal  cord in epileptics  is not
the  same as in  men or animals poisoned  by strychnine.   Cer-
tainly the excitability of the spinal cord is greater in epileptics
than in healthy persons, but the  degree of  excitability of that
nervous  centre is  much greater in persons  poisoned by strych-
nine than in epileptics;  and, therefore, it is easy to understand
that certain  excitations are able to produce general convulsions
in one case  and not in the other.
   If we give a very slight dose of strychnine to an animal, so as
not to poison it, but merely to increase slightly the excitability of
the  spinal cord, there are no  convulsions  when we touch  or
pinch or burn  the skin, but  if we prevent  breathing for a few
seconds only, general  convulsions take  place, exactly as in epi-
leptic men or animals.
   It has been said also, in opposition to Marshall  Hall,  that a
spasm of the glottis of the severest kind occurs in cases of hoop-
ing cough, of spasmodic croup and even of apoplexy, without the
occurrence of any other convulsions.   The answer to this objec-
tion is, that in epilepsy the spinal cord is more excitable than in
these other  diseases, so that the same kind of excitation does not
produce the same  effects.
   A great many  facts, that I will publish elsewhere, prove that
black blood, very probably by its carbonic acid, is an excitant of
the  spinal cord  and  of  the medulla  oblongata.   When, as is
the case in asphyxia, the blood is not oxygenated and deprived of
the  carbonic acid constantly produced in it, or received by it
from different tissues, then the excitation made on these nervous
centres becomes so powerful that convulsions are produced. This
is found in men and animals, even in perfect health.  If the as-
phyxia is incomplete, convulsions are not produced, unless the
excitability  of  the spinal cord is greater than usual, and  this is
the case in epileptics.
   In November, 1851, at  the Ecole  Pratique,'of Paris,  I pub-
lished for the first time, before  a class of about  forty  young
Physicians and Medical students,  the results of my experiments
as regards the cauterization of the larynx in  epilepsy.   About
eight months after, Dr.  Eben  Watson published  a paper* in
  * Uemarks on Dr. M. Hall's theory of the relation of Laryngismus to
Epilepsy.  In London Journal of Medicine, July, 1852. pp. 641-13. 
82
which he says :  " The treatment I would now propose instead of
tracheotomy is simply the application of a solution of nitrate of
silver,  varying in strength with the requirements of the case, to
the glottis  of  the  patient, with the view of  diminishing  the
nervous excitability of the  part in question.  A  similar treat-
ment has been found by me remarkably successful in alleviating
and removing, in a short time, the  susceptibility of the  patient
to laryngysmus, in  cases of hooping cough, and of  spasmodic
croup (laryngysmus stridulus,) nor can I see any reason why a
similar result should not ensue in chronic cases of epilepsy."
   The reasons given by Dr. E. Watson are partly the same by
which I had been  led long before  him to perform the operation
he suggests.   But I had also some other reasons. It is perfectly
known, in  the actual state of Medical  Science,  that the great-
est changes may be  produced in the nervous centres, as well as
in the  nerves, by a very strong  excitation  of the termination of
the nervous fibres in the skin or the mucous membranes.   On
this principle are founded many modes of treatment of some dis-
eases of the spinal cord and of neuralgia.   The application of
caustics, blisters, cupping, hot iron, etc., is based on this princi-
ple.  In accordance with it I am inclined to believe that epilepsy
might  be cured by a mere  application of a hot  iron to the skin
of the neck ; at least I have had two guinea-pigs cured after such
an application, repeated  three or four times.
   The operation of tracheotomy proposed by Marshall Hall has
proved successful in some cases.   But it is a dangerous operation,
and if  it is proved that another one much slighter can produce
the same good effects, it ought not to be practised.
   That other operation is the  cauterization of  the larynx;  it
prevents the  closure of  the glottis, and  thus  is able to cure
or to  relieve epileptic patients  as well as it cures some  other
diseases.  Every learned physician knows  that it is sufficient to
cauterize the  larynx once  or twice to cure hooping cough in
almost every case.
   When the cause of the epileptic  fits is excessive, and when the
spinal  cord is  very excitable,  to  allow free breathing merely
will not be sufficient to prevent the general convulsions.   But
their violence, if respiration is  free, will be deprived of all the
effect that  would be  produced by the excitation of black  blood
if breathing did not take place. 
83
   The distinction made between organic and inorganic epilepsy has
not  the importance that some  writers seem to  admit.  There
are alterations in the nervous system in both cases, and the only
difference is  that these  alterations can  be easily seen with the
naked eye in one case and not in the  other.  I ought to point
out that the cases of epilepsy in animals, which I have cured,
were cases of organic epilepsy.   These animals have been cured,
although the apparent and primitive cause of the disease, i. e. a
section  of a lateral half of the spinal cord, continued to exist.
   The  cauterisation of the larynx on  these animals was made
every day, or every other day, and sometimes during two or three
months.  In some cases,  the relief having been  immediate, the
cauterisation  was  made  only  twice  a week.    One of the
animals experimented  on  was cured after  three or  four  cau-
terisations ; but the number of cauterisations necessary has been
generally very much greater.  When I  left France in  February,
1852, I had cured about  a third of the animals  treated by this
method; and all the others, except two  or three, had been very
much relieved, and certainly many of them  would have been  cured
if the treatment had been prolonged.
   I knew that an animal  was cured, not only by  the absence of
spontaneous fits, but when I could not  produce a fit  by giving
great pain.   I had found that on any epileptic animal, except im-
mediately after a paroxysm, I could very easily produce a fit by ex-
citing pain and more particularly by pinching or burning the skin
of the face or neck. So that I am authorised  to believe that when
a fit was not produced by pinching or burning the face, it was
because epilepsy had ceased to exist.
   Some physicians in this country have already tried on man
the mode of treatment that I have found  so successful on animals.
From what I know of the results of their attempt, it seems  to
me that man is like animals in this respect.  There has not been
yet a  complete curation: but, except in  one case,  there has been
a very considerable diminution in the frequency and the intensity
of the fits.
   As  physicians who  have  to  treat  epileptics, have not  to
make  experiments, but to cure by making  use of all the best
means together, I think that  the treatment of epilepsy ought 
84
not to consist merely of the cauterisation of the larynx.   The
plan of treatment I should suggest is the following :
  1st. A cauterisation of the larynx with a  strong solution of
nitrate of silver, (at least 60 grains to the ounce,) every day, for
at least five or six weeks.
  2d.  A cauterisation of the skin of the  neck over the spine,
with a hot iron, once a fortnight, for about two or  three months.
  3d. Exercise and gymnastics.
  4th. Make use of oxide of zinc or ammoniated copper, remedies
which a very respectable physician  of Geneva, (Switzerland,)
Dr. Herpin, has found successful in many cases, when their dose
has been considerable.*
  5th. If in a fit of epilepsy the suffocation is very considerable,
the operation of tracheotomy ought then to be performed imme-
diately.

      XXVI.—CURE OF EPILEPSY BY  SECTION OF A NERVE.
  It is a well known fact that epilepsy may be produced by injury
to a nerve. Dr. John Cooke, in  his Treatise on Nervous Diseases,
says on this subject: " From the writings of Forestus, Van Swie-
ten  and Tissot, it appears that injury done  to the nerves, or that
a morbid state of them, has in many instances given occasion to
epilepsy.   In the  Edinburgh  3Iedical Essays  and Observ., a
case is related of a violent epilepsy,  which frequently  occurred,
which was produced by a hard  cartilaginous substance, of the
size of a large pea, situated upon a  nerve.   That this was the
cause was evident, as the disease ceased on the extirpation of the
tumor.  In the same we have an account of epilepsy depending
upon a calculus of an irregular figure, about the size of a nut,
pressing on a branch of the sciatic nerve; and another in which
the  par vagum was compressed by  a concretion of  a similar
kind."  Darwin, in his Zoonomia, says, " I  once saw  a child
about ten years old, who frequently fell down in convulsions, as
she  was  running about  in  play.  On examining, a wart  was
found on one ankle, which was  ragged and inflamed, which was
cut  off, and the fits never recurred."

  *  See his admirable work: Du Pronostic et du Traitement de  V Epilepsie.
Paris,  1852.  Ouvrage couronne par lTnstitut de France. 
85
  Van Swieten relates a case of curation of epilepsy by the ex-
tirpation  of a  hard cartilaginous body, somewhat larger than a
pea, situated on a nerve of the leg.
  A case is related in the 3Iedical  and  Physical Journal, (vol.
x. p. 52,) in which  a  cure  of epilepsy was effected  by the
application of caustic to the nerve which accompanies  the  vena
saphena.
  Many other analogous cases are  on record.   Jacques Carron,
(Recueil periodique de la Soc. de M'deeine de Paris, t. xviii. p.
422,) cured a  child by the  extirpation of a  small  sebaceous
tumor which existed on one of the fingers.  Portal, (Observations
sur I'epilepsie,  Paris, 1827,  p.  159,) cites  a  case observed by
Fabos,  in which the fits  were preceded by a pain in one of the
fingers.  During a violent fit Fabos put a  ligature around the
radial  nerve, and  the patient  was  completely  cured.  Portal
(Anatomic  3Iedicale, vol.  iv. p. 247,) relates  that one  of his
pupils, Mr. Leduc,  cured  an epileptic by the extirpation  of
 a hard tumor Avhich was on one of the  fingers.  Joseph Frank
 cured by castration a  patient in whom epilepsy had appeared
 after an injury  to  the  scrotum.  Ilenricus ab Heer, cited by
 Sennert, (Opera  omnia, vol. ii. p. 489,) having observed that
 during her fits, a girl  used to  rub her  two big  toes, cured her
 by the application of caustic to  these toes.  Similar cases have
 been related by Alexander, of Tralles,  and  by Wepfer.
    I have cured a guinea-pig of a  very  violent  convulsive  affec-
 tion, much resembling epilepsy, by a section of the sciatic nerve.
 This animal had been bitten by another on  the toes of one of the
 posterior limbs. A considerable slough appeared on the wounded
 part, and after two or three weeks fits  appeared, and the animal
 shortly afterwards had  many very violent fits every day.  I laid
 bare the sciatic nerve and cut it transversely.  After this  opera-
 tion I  kept the animal many months, and never  saw it have a
 fit.  From this  fact, and from those  observed by many  physi-
 cians  above  related,  it  appears  clearly  that  in  cases  of
 epilepsy it is necessary to examine if there  is  no injury whatever
 to some nerve, and  more particularly when the aura epileptica
 exists.  If there is  such an injury, the treatment ought to be
 either the section of the injured  nerve or the removal  of the
 tumor, if there is one, and sometimes the application of a caustic
 or a blister. 
86
XXVII.—LAWS OF THE DYNAMICAL ACTIONS IN MAN AND ANIMALS.*
  The following laws are based upon a very considerable number
of facts which I have observed or found on record in many books,
pamphlets  and journals.  I have collected these facts and I in-
tend to publish them in a special paper.
  I ought to say that many Physiologists,  and more particularly
Fontana,  Delaroche,  Adamucci, Broussais, Buchez, Re'veille'-
Parise,  J. Mueller, J. Paget and Carpenter, have pointed out the
existence of some parts of some of these laws.
  1. Nervous actions,  muscular contraction, contraction  of the
cellular tissue, the discharge of the electrical apparatus of some
fishes, the galvanic current  of  certain organs, the galvanic dis-
charge which accompanies the muscular contraction, and probably
also the phosphorescence of certain animals and the ciliary move-
ments, are phenomena which cannot exist without being attended
with an organic waste which nutrition alone can provide for.
  2. The faculty of originating these phenomena has a tendency
to increase in direct ratio  to the rapidity of the  circulation  of
blood, to its abundance, and to the amount of its nutritive ma-
terials,  both general and special.
  3.  During rest,  L e. at the time of the non-existence of these
phenomena, the tendency of such  a faculty towards augmenta-
tion  meeting with no obstacle, augmentation actually takes
place.
  4. The increase  is much  more rapidly effected when an action
has just been performed, than it is after a prolonged rest.
  5. Nutrition becoming altered in the tissues which remain in-
active for a long time, the  faculty of producing the above-men-
tioned  phenomena  diminishes by  degrees,  and  even  finally
disappears when the structure  of the  tissues has been  deeply
modified.
  6. The faculty of originating these phenomena increases  in
direct ratio with the  length of  the rest, within certain  limits ;
and when the latter  are  overleaped, there  is a  period when  no
change takes place; but afterwards  the  faculty decreases,  on
the  contrary, in direct ratio with the length of the rest.
  *  I ought to say that  these laws and the facts upon which they are esta-
blished, have been thesubject of many communications that I have  made to
the Societe de Biologk, at Paris, in the year 1848. 
87
  7. For many tissues which produce  these phenomena  a  com-
plete rest is scarcely possible.   The phenomena take place, in
appearance, spontaneously, and with as  much energy as the
temperature is higher.
  8. The faculty of producing these phenomena decreases at the
time they are going  on,  in  proportion  to their  intensity and
duration, and in inverse ratio to the nutritive reparation which
simultaneously takes place.
  9. Reparation thus incessantly supplying for expenditure, it
is not possible, with regard to most of these phenomena, and as
long as circulation goes  on,  to destroy entirely the faculty  of
originating  them;  or rather, as soon as we have succeeded  in
destroying that faculty, it is reproduced by nutrition.
   10.  Expenditure dependent upon action, being followed by a
great activity in the nutrition, it happens that, if the action be
frequently renewed, there is an excess of nutrition and  a  consi-
derable increase of the faculty  of acting.
    11. When the faculty  of acting has been increased in  virtue
of  the preceding reasons, within a certain limit, an equilibrium
exists between the expenditure and  the  reparation, and the in-
crease no longer takes place.
    12. As it is possible for nutrition to take place in the tissues,
 although the  nutritive fluid is not actually circulating  in them,
 and provided that  a  certain amount of it exists  in  them, the
 faculty of acting may be increased in parts where circulation is
 stopped.
    13.  Although circulation and  consequently reparation, are
 more  active in summer  than in winter time, at least  in cold-
 blooded animals, the  faculty of acting  becomes more consider-
 able in winter  than  in summer time, because the spontaneous
 expenditures abovementioned, and those due to external stimuli,
 or dependent upon the will, are by far less considerable.
    All the preceding  laws may be summed up in the following :
    The intensity of the faculty which animal  tissues  possess, of
 producing the vital phenomena, seems to be in a direct ratio  to
 the intensity and duration of the nutritive reparation, and in an
 inverse ratio to the intensity  and duration of the existence  of
 these phenomena. 
88
XXVIII.—INFLUENCE  OF  RED BLOOD  ON MUSCLES AND NERVES
            DEPRIVED OF THEIR VITAL PROPERTIES.
   James Phillips Kay* has found that blood, injected into limbs
of dead animals, just after irritability has disappeared, is capable
of regenerating this vital property. I have gone much farther, and
have discovered that blood is able to regenerate the vital proper.
ties of nerves and muscles, even in limbs which have lost their
irritability and  have been rigid for several hours.   I have ob-
tained this result from the following experiments :
   1st. On the body of a rabbit, in which cadaveric rigidity had
already existed for  10, 20, and in one case,  33  minutes,  I
divided the aorta and the vena cava in the abdomen, immediately
above the bifurcation of these vessels.  By means of small tubes,
a communication was established between  their peripheric ex-
tremity and the central extremity of the corresponding vessels
divided in a  living rabbit.   The blood of this living animal
circulated immediately in  the posterior limbs of the dead one.
After  about six,  eight or ten minutes, rigidity disappeared,
and, a few minutes  afterwards,  movements  took  place  when
I excited the muscles or the muscular nerves.
   2d. I have  obtained  a like  result from an  experiment more
easily made than  the preceding, and  which I  have  performed
more  frequently.   I divided transversely the  body of a living
guinea-pig, or rabbit, into  two halves,  on a  level with the  lower
border of the kidneys, leaving  no communication between the
two halves, except by the aorta  and the vena cava.   I then tied
the aorta  immediately below the origin  of the  renal arteries.
The muscular irritability gradually diminished, and  in a very
variable  length of timef  it gave way to  cadaveric  rigidity.   I
waited until rigidity had been fully developed  in  all the muscles,
and then the ligature  was relaxed and the circulation  re-es-
tablished.  Rigidity  disappeared slowly, and the  muscles and
the motor nerves resumed their  vital properties.
   3d. In order to ascertain if  voluntary movements  and  sensi-
bility  could  be restored to limbs that had been  in a  state  of ca-
  * Treatise on Asphyxia.  London, 1834
  t Sometimes 30, 20, or even only 10 minutes in weak  animals, and from
1 to 8 or 9 hours in strong animals. 
89
daveric rigidity, I tied the aorta immediately behind the origin
of the renal arteries, in  several rabbits.   Shortly afterwards,
sensibility  and  the voluntary movements  disappeared in  the
posterior limbs.  I waited until muscular  irritability had given
way to what is called cadaveric rigidity ; and when that peculiar
rigidity had existed for at least  twenty minutes, I relaxed  the
ligature.  Then circulation took place, and, in consequence of it,
sensibility and voluntary movements re-appeared.
   From this experiment it results, that not only local life, but all
the properties  and actions of full  life, can be restored in limbs
that have  been in  the  state  called rigor mortis, cadaveric or
post-mortem rigidity.
   4th. On a  man, 20 years old,  who was guillotined on  the
18th  of June,  1851, in  Paris,  I  made  an experiment similar
to  some of the  preceding.   The decapitation took  place at
8 o'clock A. M.   Ten hours  afterwards, i. e. ten  minutes after
6 o'clock P. M., the muscles of the hand, upon which I intended
to experiment, exhibited some slight manifestations of irritability.
At 7 and at 7» o'clock P. M. I  ascertained that they had  lost
their irritability.  Shortly after they were in a state of cadaveric
rigidity.
   I began the injection of blood  10 minutes after 9 o'clock P. M.
   As  I wished to inject  fresh human blood, and as I could  not
obtain any from the hospitals at such an hour, I was obliged to
make  use of my own.  My friends, Drs. F. Bonnefin and Des-
lauriers, drew from one of the veins of my left arm half a pound
of blood, which was immediately beaten and  completely defibri-
nated and filtered through a cloth.
   As, in opposition to the general opinion, I had found that  it is
 not necessary, in transfusion, to  make use of blood at a tempera-
 ture not far from  that of warm-blood animals. I left the blood
 employed in  this experiment freely exposed to  the atmosphere
 during all the time of the operation.  The temperature of  the
 air was 19* centigr. (66°-2 Fahr.)   I regret not having taken
 the temperature of the blood when I began to inject it, but it
 was probably about the same as that of the atmosphere.
   The injection was  made into the radial artery, a little above
 the wrist.  The whole quantity of the blood was injected in about
 8 or 10 minutes.  The arm operated on had been separated from.
                              8 
90
the body, and the blood injected came  out from all the divided
arteries and veins.
   Having  saved nearly all the blood which flowed  from these
vessels, I injected  it anew.   The  last injection  was made 45
minutes after 9 o'clock  P. M.  Ten minutes  afterwards I found
that cadaveric  rigidity had  ceased in the hand, and that two
muscles only, out of the nineteen existing in that part, had not
resumed their irritability.   Three  muscles had become so very
irritable that a slight mechanical excitation was  followed by  a
contraction in the whole length of their fibres.
   At half  past one o'clock A. M.,—seventeen hours and a half
after decapitation  and four hours after the injection of blood,—
there was still a slight irritability in the muscles of the hand.
   In this  experiment  I found  that half a pound  of  defibri-
nated human  blood was sufficient  to give irritability, for seve-
ral hours, to seventeen  of the muscles of a hand.*
   5th. An experiment   on  another guillotined  man gave me
more interesting results.   The  decapitation  had taken  place
at 8 o'clock A. M. on the  12th of July, 1851.  At  bk o'clock
P. M., cadaveric rigidity existed in almost  all  the  muscles  of
the arms and fore-arms.  I separated them from  the body, and
at 6| o'clock I ascertained that cadaveric rigidity was increased,
and that only a  few muscles were still slightly irritable.   At  8
o'clock P. M. (12 hours after the decapitation) the muscles of the
two arms were completely deprived  of irritability, and in full rigi-
dity, and the muscles of the forearms contracted only locally under
the influence of  a mechanical irritation,  and not at all when ex-
cited by a powerful magneto-electric current.   Two other exami-
nations  made, one at 9£ and the other at 10  o'clock, gave  the
same results.
   At 10| o'clock  two or three bundles  of fibres of  one of the
muscles of the fore-arm were the only parts  where a mechanical
excitation  produced a  slight  local contraction.   All the other
muscles were perfectly  stiff and deprived  of irritability.
   Twenty-five minutes  after 10 o'clock there was no appearance
of irritability remaining in any muscle.
   I then began  the preparations  for the injection of  blood, with
   * For a full account of the circumstances of this experiment, see my paper
in the Gaz. Medic.de Paris, t. vi.—1851, p. 421. 
91
the assistance of Drs. Martin-Magron, F. Bonnefin, Crouzet, and
Mr. Moyse.
   We drew about a pound of blood from the carotid of a strong
dog.  The blood was beaten and defibrinated before coagulation
could take place in it, and 10 minutes after 11 o'clock the injec-
tion was begun.  It was made in the brachial artery of the left
arm, in the middle of its length, where the arm had been ampu-
tated.   As soon as  the  blood  had been thrown in the  artery,
some reddish spots appeared in  different parts of the  skin of the
fore-arm, of the hand, and more particularly of the wrist.  These
spots became larger and larger, and the skin had the appearance
it has in rubeola.  Soon after,  the whole surface of the skin was
of a violet reddish hue.  In a few minutes this color disappeared,
and was replaced by the natural hue of the skin during life. The
skin became elastic and soft, as in a living man, and we saw the
bulbs of its hair becoming erected and presenting the appearance
called cutis anserina.  By increasing and diminishing alternately
the impulsion given to the blood, we succeeded in producing the
beatings of the pulse in the radial artery.  The veins were dis-
tinct and full as during life.
   A short time after, the  fingers, which had been extremely stiff,
relaxed, and rigidity disappeared also  in the other  parts of the
limb.
   Forty-five minutes after 11 o'clock P. M., irritability had re-
turned in all the muscles  of the limb operated on.  The degree
of irritability, more particularly in the muscles of  the arm, (tri-
ceps, biceps and others) was very considerable, and much greater
than I had seen it at the time the  corpse was first examined
(about five o'clock P. M.) Irritability was still present in  almost
all  the muscles of this limb at  4 o'clock A. M., (20 hours after
the decapitation,) when I was  obliged,  from extreme fatigue, to
 abandon further investigation.
   The blood injected was  at  23° centig. (73°.4 Fahr.) when I
began  the operation, and  the  atmosphere was at  19i°  centig.
 (60.66 Fahr.)
   In  this experiment, about  one pound of  defibrinated dog's
 blood gave  irritability  for more than  five  hours  to  all the
 muscles of a limb, from the middle of the arm  to the hand.
    6th.  Every one knows the  singular fact, that Vibriones and 
92
other Infusoria, when desiccated, will live when they are put into
water.  It is also perfectly known that seeds, after many centu-
ries, may grow when put in the earth.  I have found something
of the same kind in  higher  organisms; it is that  muscles, in a
certain condition,  after having been separated  from the body
for many days, may recover their irritability.
   Dr.  Coze, of Strasbourg, has found that  chloroform injected
into the  main artery of a limb produces instantly the strongest
rigidity,  and that  if blood is allowed to  circulate again in the
limb, life  appears  again in it.  I have gone  farther, and found
that if a limb, in which an injection of chloroform has been made,
is separated from the body, it is able, under the  influence of an
injection of blood, to recover its muscular irritability  2, 3,  4, 5
and  (in  one case)  10  days after the rigidity was produced.
I think Mr. Edouard Robin is right in admitting that chloroform
prevents the chemical changes that take place in organic bodies
after death, and, if it is so, we can understand why an injection
of blood made so long after the limb has been separated from the
body, may reproduce irritability.  One day is not more than one
hour, if, during it, there is no alteration produced in the muscles.
   It  appears, nevertheless, that  chloroform  does not entirely
prevent the alterations of muscles, because, in my experiments, I
have found  that the longer the limbs had been separated from
the body, the greater was the quantity of blood necessary to re-
produce irritability.
  7th. I lately made an experiment, with  the view of ascertain-
ing how long a limb, separated from the body of an animal, may
be  kept   alive  by  means of injected blood.  I  succeeded in
retaining  local life  in one of the limbs of  a rabbit more than
41 hours.  The animal was a very vigorous,  full grown one.  I
killed it by hemorrhage, and, two hours afterwards, rigidity had
begun in most of the muscles  of the two posterior limbs, and only
a few bundles  of muscular fibres had  still a slight irritability. A
first injection of defibrinated blood was then  pushed in  the femo-
ral artery of the right posterior limb.   Fifteen minutes after the
beginning of the injection, local life  (i. e. irritability)  was re-
stored in  the limb  receiving  blood, and cadaveric rigidity had
disappeared.
  The  manner of testing this irritability was  the same  as that of 
93
Glisson, Gorter, and all the experimenters of the two last centu-
ries—I mean by mechanical excitation. I did not use galvanism,
as it  exhausts  muscular  irritability too  much, as  Autenrieth,
Pfaff and many other observers have  shown long  ago.   Being
aware of this fact, I have always, in my preceding experiments,
made use of galvanism for a very short time only.
   Three hours  after  the  death of  the rabbit,  irritability still
existed in the right limb  (the injected one,) while  the left was
perfectly rigid  and had not the  slightest irritability.  Half an
hour  later, rigidity had begun again  in  the  right  limb; blood
wa§ injected anew, rigidity disappeared, and local life returned.
From this  moment until 11 o'clock, P. M.,  (death  had occurred
at 6 o'clock, A. M. of the same day,) blood was injected many
times.  Rigidity did not  return, and the vital property of the
muscles was maintained.   Of course the  left  limb,  during that
time, remained rigid, and had not the slightest irritability.
   From 11 o'clock, P. M. until 6 o'clock, A. M. the succeeding
day,  an  abundant injection of blood was made every twenty or
twenty-five minutes.   The irritability was  not  powerful, but it
existed in all the muscles  of the  limb.   There was  no  rigidity
 at all.
   The injections were then made more frequently—once  in each
 quarter  of an hour—until three o'clock, P. M., at which time I
was obliged  to stop them for an hour and a  half.
   At half past four  I found the limb  rigid, and only a  few
bundles  of  muscular fibres  still irritable.  A very abundant
 injection was  then  practised,  and  rigidity  soon  disappeared,
 giving way to  irritability.  From this time  to 11 P. M.,  a great
 many injections were made, and irritability was maintained.  I
 was then obliged  to  give up the experiment.   At  that moment
 irritability  was strong in all the  muscles of the injected limb,
 except some parts  of their pelvic  extremities that had  not
 received a sufficient quantity  of blood.
    The next morning  that limb was in full and energetic rigidity.
 The other limb had already lost its  rigidity, and had an evident
 smell of putrefaction.  The  third  day  after the  death of the
 animal,  rigidity was strong in the injected limb, while the other
 was  in an advanced state of putrefaction.
    If we compare these two limbs, we find, 1, That  the injected 
94
one had a strong irritability at the end of forty-one hours after
the death of the animal; 2, That its rigidity gave way to putre-
faction only at the  eightieth hour;  3, That it was  in complete
putrefaction only at  the  ninety-fourth hour.    The other limb
was  in  full rigidity  at  the fifth hour  after  the death of  the
animal;  its rigidity  gave way to  putrefaction at the forty-
eighth hour; and it was in complete putrefaction at the seven-
tieth hour.
  From all the experiments above related, it  appears that  life
may be  reproduced or maintained in muscles and nerves  by
mere injections of blood.   I have found, also, that  life  maysbe
reproduced  by the  same  means in  the spinal  cord  and  in  the
brain.   I will publish these facts in another article.
  It is  nearly indifferent in these experiments whether we  use
venous or arterial blood; but it is absolutely necessary to employ
red blood, i. e. oxygenated blood.
  I have tried,  sometimes,  arterial blood, rendered black by
the substitution of  nitrogen or hydrogen  for a great part of its
oxygen, and I have found that such blood was unable to repro-
duce the vital properties of nerves and muscles.
  Oxygen is necessary, either because it prevents the blood-glo-
bules from being altered, or because it acts directly on muscles, as
Gustavus Liebig has  found it does on their  external  surface,
when exposed to air.   I believe it is necessary for both these rea-
sons.
  I  cannot  say how long  after the beginning of  cadaveric
rigidity in  a muscle, oxygenated blood can  reproduce  local life.
In  the  second of  the two  decapitated men, on  whom I ex-
perimented, rigidity had existed  at least five hours  before the
injection was begun.   I believe that  the stronger the animal is,
the more easy it is to reproduce  local  life  in rigid limbs, by
injection  of blood.  In limbs  of weak rabbits,  I have  found  it
impossible, two hours after the beginning of  cadaveric  rigidity,
to reproduce local life. In a very strong dog I have reproduced
muscular irritability  four hours after rigidity had been fully
developed.
  Ten,  twelve, or fourteen hours after rigidity had  taken place,
in human limbs, I have tried in vain to re-establish  local life.
  I have ascertained that pure serum of blood, or milk, or albu- 
95
men of eggs, are unable to  produce any apparent  change  in
rigid limbs.
  The following conclusions  are to be drawn from  the facts
related in this article :
  1st. Red blood, i.  e.  richly oxygenated blood  (arterial  or
venous) is able to revive irritability in muscles, four or five hours
after these organs have lost this property.
  2d.  Red blood is  able  to revive  the  vital properties  of
nerves and nervous centres, when these properties have not been
lost for more than about an hour.
  3d.  Muscular irritability can be maintained  for more than  41
hours, by mere injections of blood, in limbs  separated  from  the
body of a rabbit.
  4th. Muscular irritability may be re-established in limbs ren-
dered  rigid by chloroform for many  days, even ten days.

XXIX__CASES OF LOSS OF SENSIBILITY ON ONE SIDE OF THE BODY.
    AND LOSS OF VOLUNTARY MOVEMENTS ON THE OTHER SIDE.
   It has been objected to me that if the transmission of sensitive
impressions, in  the spinal cord, takes  place, as I have tried to
prove in a former part of this sketch (Art. XIX,) so that those
coming from the left side of  the body, are  mostly conveyed to
the sensorium along  the right side of  the  spinal  cord,—et vice
versa__physicians  should  have some  times  found in man the
same thing that I have discovered in animals.
   Many reasons have prevented physicians from making such a
discovery:  In the first place, an injury or a pathological  altera-
 tion, limited  to  a lateral half of the  spinal cord, is very rare.
 Besides, the idea that  there is no crossing of fibres in the spinal
 cord,  has  been an obstacle to a thorough examination of many
 pathological cases, and it has been so in a case observed by Boyer.
    There  are but few cases  on record in which  there was  a  loss
 or  a  diminution  of sensibility on  one side, and of  voluntary
 movements on the other.   I will give  here a  short  account of
 some  cases of that kind, which are very interesting.
    The first one I will relate has been observed  by Boyer:
    A drummer, of the National Guard of Paris, received a wound
 in  the back of his neck.  A sword had been thrown at him, and
 had penetrated the superior part of the right lateral  half  of the 
96
neck.  An incomplete paralysis of movement took  place in  the
right side of the body, and, some time after, it was accidentally
discovered that  sensibility was lost in  many parts  of the  left
side of the body.   After twenty days the wound was cured,  and
the man went out of the hospital, still paralysed.
  From what we know of that case, it appears that the sword  had
incompletely divided the right lateral  half of the spinal cord.
The paralysis of  motion  on  the right  side  of the body  was
certainly produced  by the  division of  a part  of  the  anterior
column,  and, as the instrument had penetrated the right  side of
the back of the  neck, it must have divided the parts between the
anterior column of the spinal marrow and the external surface of
the right side of the neck.   These parts, besides the muscles  and
bones, are the lateral and posterior columns  and the gray matter
of the right half of the spinal cord.  So that in this case nearly
the same injury and also the same  morbid  phenomena had ex-
isted as  in the animals on which I have divided a lateral half of
the spinal cord.
   The following case is still more interesting.   It has  been re-
corded by Dr. R. Dundas,  Surgeon of the Hospital of Bahia.
   A mason fell on his back from an  height of 20 feet.   After
having recovered  his consciousness, he  discovered  that all  the
left side of his body, from the shoulder to the foot, was paralyzed
as to  motion, without the slightest alteration of sensibility,  and
that the right side in which the movements were free,  was com-
pletely deprived of sensibility.
   Three important facts, precisely like those I have discovered
in animals after the transversal  section of a lateral half of the
spinal cord, existed in  this  case :
   1st. A morbid exaltation of sensibility in  the side where move-
 ment  was lost.
   2d. A diminution of temperature in  the  side where  the para-
lysis of sensibility existed.
   3d. An increase in temperature in the side where the paralysis
 of movement existed.*
   * In  a former part of this sketch  (Art. xxii.) I have  related facts proving
that animal heat may be  increased after injuries to the spinal cord. I have
learned since, that Prof. D. Gilbert has observed a case of fracture of the
spine, in which the temperature of the paralyzed parts  was increased.  Prof.
 Dunglison has also stated that the paralyzed side in hemiplegic patients
may have an elevation of temperature. 
97
   When Dr. Dundas published this curious case, the patient was
living and improving ;  so we do not know what was  the altera-
tion existing in the spinal cord.
   II. Ley, in a letter to Sir Charles Bell, relates  the following
case:f
   Mrs. W., after a profuse hemorrhage, became paralytic. Upon
one side of the body there was a loss of sensibility, without, how-
ever, any corresponding diminution of power in  the muscles  of
volition.  The breast, too, upon  that side, partook of the insen-
sibility, although the secretion of milk was as  copious as in the
other.  She could see the child sucking and swallowing, but she
had no  consciousness, from feeling, that  the child was so  occu-
pied.
   Upon the opposite side of the body  there was defective power
of motion, without, however,  any diminution of sensibility.   The
arm was incapable of supporting the child ; the hand  was power-
less in its grasp ; and the leg was moved wdth difficulty, and with
the ordinary rotatory movement of a paralytic patient;  but the
power of sensation was so far from being impaired that she con-
stantly complained of an uncomfortable sense of  heat, a painful
tingling, and more than  the usual degree of uneasiness  from
pressure, or other modes of slight mechanical violence.
   She again proved pregnant.  Her delivery was easy : but after
about ten  days  she complained of numbness on both sides.
Her articulation was  indistinct;  she became more  and more in-
sensible, and sank,  completely comatose.
   No positive  disorganization of the brain  could be detected.
The ventricles, however, contained more than usual serum ; and
there were  found  thickening and increased vascularity of the
membranes, with  moderately  firm adhesion in some parts;  in
others, an  apparently gelatinous, transparent and  colorless de-
posit  interposed between them.
  Unfortunately, no  examination of the  spinal cord was made.
   In this case there  was very likely, as in my experiments, an
increase in the temperature of the side paralyzed of motion.  The
writer merely says that the patient  was constantly complaining
of an uncomfortable sense of heat.  There  was, as in my animals,
an evident increase in sensibility on that side.
  fThe nervous system of the human body.  By Ch. Bell.  3d ed.  London,
1844, p. 245. 
98
   M. Monod* has related the case of a man who, after having
felt a sudden pain in his back, became  paralyzed in the motion
of the right  inferior limb.   Sensibility was entire on this side,
but on the left side, where the movements were entire, sensibility
was entirely lost from the breast to the  foot.  There was at first
no fever.  The patient died 34 days after the beginning of this
affection.
   The brain and its membranes were  normal.   A hemorrhage
had taken place, and blood was found in  the right side of the
central gray  matter, in the neighborhood of the anterior column
in the dorsal and lumbar regions.
  This  case  is assuredly a very remarkable  one,  and in accord-
ance with my experiments.
  The conclusion to be drawn from these four cases is, that in
man as well as in animals, there appears to be a crossing of the
sensitive nerve-fibres in the spinal cord.

XXX.—ON  THE  DIFFERENT  DEGREES  OF EXCITABILITY OF  THE
      DIFFERENT PARTS OF THE SENSITIVE NERVE-FIBRES.
  It is a well-known fact, that an excitation of the skin or of a
mucous membrane, produces a greater pain or a greater reflex
action than that of the nerve trunk, from which  these parts re-
ceive  their nerve-fibres.  For instance, a slight excitation of the
laryngeal mucous membrane produces coughing, while an excita-
tion  of the vagus nerve  very rarely produces the same  effect.
Therefore,  there is a notable difference between  the peripheric
extremity of a nerve-tube and its part contained  in  a nerve-
trunk.
  The existence of a peculiar  organ in the skin  (the corpuscles
of touch of Wagner) has not much (if it has anything) to do with
the different  degrees of excitability of nerve-tubes in the skin
and in the trunks of nerves.   The corpuscles of touch do not
exist in the mucous membranes, and if they exist in the skin of
frogs, turtles, etc., it is in a very small number ;  and, neverthe-
less, the  degree  of excitability of nerve-fibres in these parts is
much superior to that of the fibres of the nerve-trunks.
  Some  very striking  differences exist  in the degree of excita-

         * Bulletin de la Societe Anatornique, No. xviii. p. 349. 
99
bility of centripetal nerve-fibres in the five  following  different
parts of their length.
  1st. The part contained in the skin.
  2d.  The part of a nerve extending from the skin to the spinal
cord.
  3d.  The posterior roots of the spinal nerves.
  4th.  The  part of the  posterior roots attached to the  spinal
cord.
  5th.  The part of the cutaneous  nerve-fibres contained in the
gray matter of the spinal cord.
  The fibres existing in the gray  matter of  the spinal cord ap-
pear to be inexcitable, at least by  our ordinary means  of excita-
tion.   Of the four  other parts, the less excitable is the nerve be-
tween  the ganglion and the  skin.  The excitability of the pos-
terior  roots is less  than that of the skin and that of their part
attached to the spinal cord.   Of these two last parts the skin is
less  excitable than  the other.
   I measured the excitability by the degree of pain or of reflex
action.  The differences are much  more easily found for the re-
flex action than for the pain.
  Is it because  they have been  connected with the cells of the
central gray matter of the spinal cord, that the centripetal fibres,
contained  in that   gray matter, are not excitable ?  If it is so,
there  is a difference between  these cells and  those of the gan-
glions on the posterior roots, because the connection of these fibres
with the cells of these ganglions  does not prevent their being
excitable.*
  From the facts above related I conclude  that the same nerve-
fibre, in different parts of its length, may have very different de-
grees of excitability.

     XXXI.—THE  AUDITIVE  NERVE IS A NERVOUS  CENTRE.
  In an  anatomical point of view there is no  doubt  that the
auditive nerve is a  nervous centre.   This is proved  by the fact
that cells of gray matter are found, not only in the terminal part
of the nerve, but  also in its trunk, in many  animals, according
to the  researches of Stannius, Corti, Kolliker, and  myself.
  In a physiological point of view, the fact  I  have discovered,
(see  Art. V. p. 21,) viz., that any  injury to the acoustic  nerve 
100
produces turning, is sufficient to prove that it is a nervous centre.
  The degree of pain produced by an excitation of this nervous
centre appears to be as considerable as that caused by a similar
excitation of the trigeminal nerve.   I will publish soon an ac-
count of the strange effects produced in different parts of the body
in consequence of an injury of that nervous centre.  I will merely
say here that, after such an injury, there  are muscles  which
appear to be slightly paralyzed.  Besides, there seems to be a
notable  hyperaesthesia of the skin everywhere.
  Flourens has found that  a section  of the  semi-circular canals
in birds and some mammals produces a peculiar disorder in the
movements of the head, and, in some cases, turning.   He says
that the auditive  nerve  must be considered  as composed of two
nerves:  one going to the semi-circular canals and possessing a
peculiar power on  the  movements of the body, and  the other,
the vestibular or true auditory nerve.   What I have found  on
frogs is in opposition to  these views.   A section of the semi-
circular canals, in these amphibia, does  not produce any effect
on the movements of the  body, and the  slightest excitation of
the true auditive nerve is sufficient to produce pain, hyperaesthe-
sia, turning, and  other strange effects  on many muscles of the
body.
  I have sometimes seen turning produced after the mere laying
bare of the kind of bladder, containing the terminal  part of the
auditive nerve, in frogs.  So slight  may be the  excitations  on
that nerve sufficient to produce  turning, that very likely turning
after the  laying  bare of that bladder was  the result of  some
slight mechanical injury of the nerve.  The rapidity of turning
and the smallness of the circle  then  described are in proportion
to the degree of injury to the nerve.    When  the two  auditive
nerves are injured, the animal turns on  the side  most injured.
Sometimes, instead of turning, the animals roll around the longi-
tudinal  axis of their body; this takes  place  in very strong
animals after the terminal part of  the  nerve has been entirely
crushed.
  In frogs deprived of their cerebral lobes, the same effects are
produced after injuries of the auditive nerve, as in unmutilated
frogs. 
101
XXXII.—ON APPARENTLY SPONTANEOUS ACTIONS OF THE CONTRAC-
             TILE TISSUES  OF THE ANIMAL  BODY.
  All the contractile tissues of the animal body (the muscles of
the trunk and limbs, the muscular layers of the digestive canal,
the iris, the uterus, the dartos, the cellular tissue, etc.) present,
sometimes,  apparently spontaneous  contractions.  I give this
name to contractions which are not the result of  an external
excitation or of an excitation produced by the nervous system on
the contractile tissues.  These contractions may be permanent
or momentary, rhythmical  or irregular, slight or  very powerful.
One of their  causes, if not their only cause, appears to  be an
excitation  directly produced on  the contractile  fibres  by  the
carbonic acid existing in the blood.
   1.  Contractions in the muscles of the face after a section of the
facial nerve.—My friend Dr. Martin-Magron and  myself have
discovered that after the section of one of the facial nerves, on a
rabbit, the face becomes very quickly deviated, not  on the healthy
side, as  it  is known to be  in man, but, strange  to say, on the
paralysed  side.   The  deviation,  very  slight at  first, increases
gradually during one or two weeks, and then it is so considerable
that the middle of the lips is  at a  distance of four, five or six
lines from its natural situation.   There is an evident  state of
contraction in all 'the paralysed muscles.  When the animal  is
excited,  or when  its respiration is  somewhat  disturbed or pre-
vented, the paralytic muscles tremble, and sometimes they have
rhythmical contractions and relaxations.
   The contractions of these muscles may be so considerable that
the bones  themselves, and, secondarily, the teeth,  may be de-
formed. In one case, on a rabbit which I had kept living twenty-
 one months after the extirpation of one of  the facial nerves, not
 only the superior and inferior jaws were by far less  developed on
 the paralysed side  than on  the  other, but the anterior part of
 the superior maxillary bone was deviated towards the paralysed
 side, so that the middle line of the roof of the mouth was curved
 and presented a great concavity on the paralysed side and a cor-
 responding convexity on the other.
    When the two facial nerves  have  been divided, there is no 
102
 deviation, but there is an evident state of contraction in all the
 paralysed muscles, particularly around the lips.*
   When  one of  the facial  nerves is divided on  a  dog,  on
 a cat, or on a guinea  pig,  there is generally  no  deviation
 on either side.  But very frequently there are  convulsive move-
 ments,  and  sometimes rhythmical contractions,  in  the para-
 lyzed side of the  face.  One of these two kinds of movements
 always exists in young cats.   They are  increased, or  produced
 when they do not exist, in dogs  and  guinea-pigs, almost every
 time we prevent the animal from  breathing freely.  Once, on a
 very vigorous guinea pig, upon  which one of the  facial nerves
 had been torn  away, I saw alternate  contractions and relaxa-
 tions taking  place, without a relapse, for eight or ten days after
 the operation in the paralysed muscles.  After that time, these
 tremblings appeared only when  the circulation and the respira-
 tion were rendered very active, or when the respiration was pre-
 vented or diminished.  In the case of an impaired respiration,
 the strength and frequency of these movements were in propor-
 tion to the degree of asphyxia.  During many months, the same
 phenomena existed in this animal.
   I ought to say  that in  all the experiments above related, the
 nerve could  not  have any share in the movements, because,
 the fifth  day after the  division, or after  the  extirpation of  a
 portion  of it,  the  peripheric part  had entirely  lost its vital
 property.
   In  man,  as   Duges justly  remarks, as  long as there is no
 attempt  at movement, voluntary  or emotional,  the face remains
 without any  deviation, in cases of facial hemiplegia, which have
 not lasted a long time.
   2.  On spontaneous rhythmical or irregular contractions in
 muscles of animal  life, after death—It is a very important fact
 in connection with  the theory of  the action of the heart, as I
 will try to prove hereafter, that  other muscles,  and particularly
 muscles of animal life, are capable of having rhythmical move-
 ments.  This fact  I have discovered in the following  cases:
   a. After the division of the nerves of the ischiatic and lumbar
  * Dr. Martin-Magron and myself have found that death occurs from inani-
tion in all the species of mammals on which we have divided the two facial
nerves.  After  the  operation they cannot swallow : we do not know whv. 
103
plexuses, on  one side, in mammals, if we suddenly asphyxiate
the animal, we  see, at  first, convulsive movements in the three
limbs and in other parts of the body not paralysed.   After one,
two or three minutes, these movements cease, and there are only
some  tremblings in the muscles of  these parts.   The paralysed
limb has no movement  at  all during one  or two minutes, after
which time, suddenly, contractions in many bundles of muscular
fibres partially take place.   In the  same bundle the contractions
sometimes  appear to come regularly one  after  the other.   In
some  cases I have seen, besides these tremblings, movements of
the entire limb,  consisting of some successive flexions and exten-
sions  of the limb,  and after  these  movements had ceased, con-
tractions limited to various bundles  of fibres appeared.  In these
cases the action of the muscles began very late after death,  and
once, only six minutes after the beginning of asphyxia,  which
lasted two minutes and a half.
   b.  Nearly the same movements  of which I have spoken as
existing  frequently in the face, during life, in rabbits and guinea-
pigs,  after the section of  the facial nerves, exist always,  either
during agony or a little after  death.   They are generally pro-
duced by partial contractions  and relaxations of  the different
bundles of fibres of the various muscles.  It is rare to see  all
the bundles composing one muscle contracting together.   These
phenomena last five, six  or  eight  minutes after the last  respi-
ration.   There are also such movements in the face during agony
and after death, when the nerves have  not been  cut and when
there is no paralysis;  but then the movements appear later  and
do not last so long as in paralysed muscles.
   c.  I have seen in many rabbits apparently spontaneous rhyth-
mical contractions in the respiratory muscles.    In  about ten
rabbits,  out  of forty or  fifty, the following phenomena were
very  decided; on the others they were slight,  and  sometimes
very  slight,  but in  all cases a  part of  them always  existed.
I open the abdominal cavity and expose the bowels to the action
of a  cold atmosphere, so as to  lower  the temperature of the
animal;  after some minutes I make a little opening in one side
of the chest, and, at last, after a few minutes more, I open
largely one side of the chest.  Generally, in such circumstances,
the respiratory movements continue to take place with energy. 
104
 I then take away the sternum and divide the two diaphragmatic
 nerves. The movement of the diaphragm, nevertheless, continues,
 and it exists  rhythmically together with the  movements of the
 other respiratory muscles.   Six, eight or ten minutes afterwards
 the movements of the diaphragm are still regular, (there are from
 five to twenty contractions in a minute;) the intercostal muscles
 present then only partial contractions.  The different bundles of
 fibres of these muscles contract separately one after the  other,
 but the same bundle has generally regular contractions and re-
 laxations.   At that time I destroy the spinal cord, and see that
 the movements of the diaphragm and of the intercostal muscles
 are not changed after this operation ; they last  for nearly a quar-
 ter of an hour, and in some  cases much longer; their regularity
 subsists.   In  the diaphragm, long after the general movement
 has  stopped,  there are regular or  irregular contractions  of
 many bundles  of  fibres for one, two, three hours, and sometimes
 more.
  3. Deviation of limbs produced by  a contraction of paralysed
 muscles___In pigeons, after the destruction of all the lumbar part
 of the spinal cord,  the two posterior limbs are completely para-
 lysed.   The muscles then are soft, and the different parts of the
 limbs do not resist at all, when we try to put them in flexion or in
 extension.   But after a few  days  the paralysed muscles become
 harder, and after a few weeks there is an evident state of con-
 traction in them.   The limb is generally kept in a state of exten-
 sion,  and deviated  on  one   side  or the other.  The deviation
becomes considerable after some months.
  Very likely  it is  owing to the same cause that club-foot and
other deviations are produced in embryos, after a destruction or
an absence of development of the spinal  cord.
  4. Rhythmical movements  in the eye  of the Ink-fish.  (Loli^o
sepia, L.)—The ciliary muscle so well described by Dr.  W. Clay
Wallace, of New York, in the eyes of superior animals, is strongly
developed  in the ink-fish.  After an eye  of this mollusc has been
separated  from the  body, I have sometimes found very singular
and perfectly  rhythmical movements produced  by the ciliary
muscle.  These movements consisted in  alternative contractions
and relaxations of some parts of that muscle.  At every contrac-
tion a notable  depression was produced in one portion of a zone 
105
 corresponding to the circumference of the cornea.*  In one case
 I have found four times in fifteen minutes the same rhythm ex-
 isting in one part of the ciliary muscle.   At each of these four
 examinations I have found sixteen contractions in  one minute.
   5.  Spontaneous  Contractions  of the  Uterus.—I have  seen
 hundreds of times the uterus or its cornua, full or empty, contract-
 ing to appearance spontaneously, after the death of rabbits and
 other animals, at a time when the spinal cord had entirely lost,
 not only its reflex power, but also the  power of acting on mus-
 cles when directly excited  by galvanism, by warmth or mechani-
 cally.f
   I have also seen movements taking place in the uterus  and in
 its cornua, in recently dead animals, the  spinal cord of which I
 had  destroyed  in all its length.   The same movements  I have
 found after I had taken out from the abdomen of a living animal
 the whole uterine apparatus.  I have found sometimes that after
 I had put a ligature around the trachea of guinea  pigs, which
 were at the end of gestation, parturition took place and was pro-
 duced by three  causes :  1st, a direct excitation of the spinal cord
 by the venous blood; 2d, a  direct  excitation of the uterus by that
 blood; 3d, a reflex  action  of the spinal  cord.  In two cases I
 have seen delivery taking place after the  action of one only of
 these three cases, namely,  the direct  influence of black blood on
 the uterus of the Guinea pigs, the spinal cord of which I had de-
 stroyed from the sixth costal vertebra to the sacrum.   The more
 complete and sudden is the asphyxia, in a rabbit or a Guinea pig,
 during labor, the more certain will the delivery take place.
   Dr. Tyler Smith speaks of  a peristaltic  action  of the uterus,
 which may expel the child when the mother has died  during la-
 bor, undelivered.  He has not attempted at all to explain that con-
  * The eyes had not been opened.
   •j-Dr.  Tyler Smith, in his very original  book on Parturition, (London,
 1849, p. 40,) says  that "a slow reflex action of the uterus may possibly con-
 tinue long after the rhythmic respiratory actions have ceased ; as long, in-
 deed, as the bodyretains its warmth." There is a great error in these lines,
 about the relation between the warmth of the body and reflex action.  We
 may observe reflex actions even in animals that have lost 10, 12 or 15°  Cents.,
 (18, 22 or 27° Fahr.,) of their temperature, and, in certain circumstances,
 these actions may  be, then, more powerful than  if the temperature of the
body was normal.   For instance, if we decapitate an animal  after having 
106
traction, i. e. to find  out its cause  and the circumstances which
favor or are opposed to its existence; besides, he has not demon-
strated that the peristaltic contraction is entirely independent of
the nervous system.
   6.  Spontaneous rhythmical movements in the crop and oeso-
phagus of pigeons and other birds.—I have found that if the crop
of a bird, and  more  particularly of a pigeon, is opened during
digestion, some rhythmical movements are frequently seen in it
and in the oesophagus.  Ordinarily these movements are perfectly
regular.  They begin in the upper part of the crop, and are pro-
pagated from there to the oesophagus.  If the animal is asphyx-
iated, these contractions become very energetic. Their ordinary
number, in a minute, varies from ten to twenty.
   I  have  ascertained  that these rhythmical movements take
place as well in a crop and oesophagus separated from the animal,
as in these same parts left in situ.  Therefore, the nervous cen-
tres are not the source from which originates the excitation which
acts on the muscular fibres to put them in contraction.
   7.  Spontaneous movements in limbs of persons who have died
of cholera.—It is known that after death by cholera, the whole
body, and more particularly the limbs, have  sometimes very con-
siderable movements.   In some cases  I have  seen alternative
movements of  flexion and extension of the arms or of the legs,
 even three hours after the cessation of the beatings of the heart.
 Physicians who know how quickly after death the nervous system
 loses its vital powers, will admit easily that these movements can-
 not be the result of an  action of that system. I have ascertained
 on more than  sixty bodies of men who died of cholera,  or of
 various other diseases,  that a short time before, or a very short
 time after the cessation of the  beatings  of  the heart, no reflex
 put a ligature around the carotid and vertebral arteries, we find, when  pul-
 monary insufflation is made carefully, that two important phenomena  take
 place—one is a gradual rapid loss of temperature, if the atmosphere is cold,
 (this is the well known fact discovered by Sir B. Brodie,) and the other is a
 gradual and considerable  increase of  the reflex faculty.  It has  been  in
 Buch cases that I have found the greatest degrees of reflex power in mam-
 mals.  The nervous power accumulates to such an extent in the spinal cord,
 that if we pinch the skin in any part of the body, but more particularly  on
 the chest and on the anterior limbs, a reflex respiratory movement takes
 place. 
107
action was produced by the tickling of the sole of the foot.  The
greatest duration of reflex action that I have observed after death
has been in a case  of cerebral apoplexy.   It has lasted thirteen
minutes after the last breathing, and about eight minutes after
the last beating of  the heart.  Dr. Bennet Dowler has recorded
many curious facts  (observed in cases of death from yellow-fever,
cholera, etc.,) from which he concludes also that the movements
taking place in the limbs are not reflex actions.
   I have found that, in general, the more sudden and complete
has been  the asphyxia before death, by cholera, the more the
limbs are moved  after death. I have found also that it is in pa-
tients who have  died during  the algid period that  these move-
ments are ordinarily found.
   These facts, as  I will  show hereafter, appear  to  prove that
these movements,  like  the other movements, of which  I have
previously spoken,  are excited by carbonic acid alone, or toge-
ther with the poison of cholera.
   8.  Spontaneous  contractions of the bowels, the bladder,  the iris
and other parts of  the body.—It is known that frequently at the
time  of death, many of the contractile tissues of the body are
put into contraction.  I can go farther and say that  it is  so with
all the contractile tissues;  and that, contrary  to  the  general
opinion, a nervous  action is not necessary for these contractions.
   There are contractions  in all the following  organs or tissues
during agony and  after death :  1, the muscles of  animal life ;
2, the sphincter of the anus ; 3, the respiratory muscles; 4, the
iris;  5, the digestive  canal (in  all its length);  6, the  urinary
bladder;  7, the  uterus;  8, the scrotum,  (dartos);  9, the gall-
bladder;  10, the  ureters;  11, the  seminal  vesicles; 12, the
bronchial  tubes; 13,  the skin; 14, the blood-vessels;  15, the
lymphatics ; 16, the cilia.
   As to the skin, in many cases  the so-called goose-flesh (cutis
anserina)  takes place a little before or little after death, although
the body has not yet become cold.  I have seen it very strongly
marked on the inferior limbs of a paraplegic who died of a soften-
ing of the dorso-lumbar part of the spinal cord.   It results from
this fact that the cellular tissue is able to contract from the same 
                              108

cause which produces contractions at the time of death, in mus-
cular tissues—that is, very likely, carbonic acid.*
  Besides, I have found contractions of the cellular tissue of the
skin of the face, in animals killed by asphyxia, and on which the
facial nerve had been divided for many days or weeks.
  In the same man who had a paraplegia, and of whom I have
just spoken, I saw very strong contractions in the dartos, during
agony.
  In animals  suddenly asphyxiated, after the destruction of the
dorso-lumbar  part of the spinal cord, the seminal vesicles some-
times contract, and a slow ejaculation takes place, although there
is no erection.
  In the sphincter of the anus, when  it is paralysed, there are
only slight contractions,  but they are evident.
  The urinary bladder, during agony or after death, sometimes
contracts so much, even when it is paralysed, that all the urine
it contains is  expelled.
   The ureters present  very strong  contractions, in  animals
recently killed by asphyxia, and these contractions in some cases
are  rhythmical.   The  same movements are  seen when all the
wrinary apparatus is in situ, and  when it has  been removed from
the abdomen, and therefore separated from the nervous centres.
The contraction begins at the kidney and thence is very quickly
propagated all along the ureters to their termination in the blad-
der.   Among the contractile tissues, that of the ureters is one
of  the most irritable.
   Bidder and Schmidt, of Dorpat, have recently found that after
the division of the two pneumogastric nerves, there is more car-
bonic acid expelled by the  lungs than usual.  This fact is very
  * Kolliker has recently discovered  fibro-muscular  cells—that is, mus-
 cular fibres of organic life—in the skin, p'i i he maintains that the cutis
anserina is produced by these fibres, and not by the cellular fibres.  I have
published facts which, I think, prove conclusively that the contractions in
 the  skin are in a great measure  performed by the cellular tissue.  (See
 Comptes Rendus de la Soc de Biologie, 1849, t. i. pp. 134 et 157, et 1850,
 t. ii. p. 132.)   Since tha.t time, I  have found that  in  some cartilaginous
 fishes, in which the irk does not  contain any muscular fibre,  and is  com-
 posed of cellular tissue, this  membrane  may be the seat  of considerable
 .contractions ; so that I consider it as perfectly certain that the cellular tissue
/at least in socae organs)  is contractile. 
109
important, because  if the theory, which I am about to propose,
be true, we ought to see a contraction produced in the bronchial
tubes, in consequence of the unusual  amount  of carbonic acid
that they contain.   Now, such a contraction certainly exists then,
and it is it which causes the well-known difficulty in  the  expan-
sion of  the chest, which exists in that case.
   In the eyes, even when they are paralysed by the section of
the three nerves of the iris, (the third pair, the sympathetic, in
the neck, and the ophthalmic nerve,) the pupil may, at first, con-
tract and afterwards dilate very much.
   The lymphatics and the thoracic duct contract very much after
death.   I have, sometimes, in  cases where  these vessels were
dilated  by chyle, introduced  a glass tube, two lines in diameter,
into the thoracic duct, and I have seen  the liquid ascend into the
tube, and in  one case run out, although the  tube was five inches
high.
   The cilia are  known  to have movements  independent of the
nervous system.
   The  gall-bladder contracts little and slowly, but evidently,
after death, even when it has been, with the liver, removed from
the abdomen and separated from the nervous centres.
   The choledoch duct and the pancreatic duct, as my friend Cl.
Bernard has  discovered, have rhythmical contractions during life,
in birds.   I  have found these movements perfectly regular after
I had removed all the viscera from the abdomen.   Therefore the
cause  of these  rhythmical contractions is  not  in  the  nervous
centres.
   The bowels have considerable  contractions during agony and
after death;  and I will prove hereafter that the cause  of these
movements is not the influence  of cold, or that of air, when they
are  exposed  to  the atmosphere.  Nurses, in France, are in the
habit of judging that  death has positively taken place, when,
after the cessation of breathing, they see urine and faecal matters
expelled.  This  expulsion depends  upon the contractions then
taking  place in  the bladder and in the bowels.
   9. Causes of the apparently spontaneous  contractions during
life  and after  death.—All  the contractions of  which I have
spoken, appear to me to be produced by an excitation made upon
 the contractile  tissues by a substance  existing in the blood, and 
110
the quantity of which becomes much increased during asphyxia.
The relations between these contractions  and  asphyxia are evi-
dent.  A great  many  of them  do not  exist unless asphyxia
exists, and their energy is always in proportion to the degree of
asphyxia.
   I believe that the substance in the blood which has that power
is the carbonic acid.   In admitting this  opinion we  can easily
explain all the phenomena.
   There are  certain contractions which  take place in  muscles of
animal life, after  death, and which have quite another  cause.  In
the cold seasons, it is not uncommon to find, in limbs of  frogs,
when we separate them  from the body, apparently spontaneous
contractions, lasting sometimes for half an hour or even more  ;
but these contractions have begun when we have cut the nerves,
and they continue on account  of galvanic discharges which ac-
company them.   The  fact that they begin after the excitation of
a nerve,  is sufficient to show that they are  not like the other con-
tractions, of  which I have previously spoken.
   Some  of the facts  I have related may appear  to be distinct
from the others.   So, for instance, contraction taking place in
paralysed muscles of  the face or of the limbs in living animals,
might be considered as quite different from the contractions exist-
ing after death.  I think that they originate from the same cause,
viz., an  excitation by carbonic acid.  A muscle may be moved
or not be moved by an excitant.  If the degree of irritability is
greater in one case than in another, we may see the same amount
of excitation produce a movement in the first case,  and not  in the
second.   If the amount  of excitation increases, then we may see
both muscles moved, but the most irritable more than  the other.
This  is sufficient  to explain why the paralysed muscles may be
moved by the carbonic  acid existing in the blood during life,
while the muscles  that are not paralysed are not moved.   I have
found that the degree of irritability increases, during a certain
time after paralysis, in the muscles of animal life.   Their irrita-
bility being augmented,  they are excited sufficiently to contract,
by a quantity of carbonic acid which  is not  sufficient to act on
the other muscles.
  The following facts  and reasonings will, I believe, prove  that,
at least in  the  bowels, black blood, very  likely by its carbonic 
Ill
acid, may excite powerful movements.   It is known that when
we open the abdomen of an animal immediately, or a short time,
after  death, we generally see considerable  movements  in the
bowels.   These movements have been attributed to the action of
air, or to that of cold, on the bowels.  This is not a right view.
A sudden exposure to a cold atmosphere may, possibly, produce
contractions in the bowels; but certainly cold is not the ordinary
cause of these movements.  At first, they may exist in a warm
atmosphere, and then  they appear to  be more rapid  than in a
cold atmosphere.  Besides, the bowels may be exposed to a cold
atmosphere, and remain motionless, although they have their en-
tire irritability.  As  to atmospheric air, it is not able to excite a
movement  in  the  bowels.  If we open the abdomen of a living
animal, in avoiding to excite mechanically the bowels,  and in al-
lowing the animal  to breathe freely, we may for a long time see
no other movement  in the bowels, except, sometimes,  slight re-
gular and  natural peristaltic motions, depending on  digestion,
and  limited to some  small parts of the bowels. The  animal must
be kept on his back, and we must avoid touching the bowels, be-
cause a slight contact is sufficient to produce movement.  Now,
if we prevent the animal from breathing, we see, after ten, fif-
teen, or twenty seconds, very violent, sudden, and rapid contrac-
tions taking place in all parts  of the intestine, from the stomach
to the rectum, but  much more in the small  intestine  than  else-
where.   These movements are quite different from the digestive
peristaltic movements.  If the animal is allowed to breathe again,
and freely, the movements diminish gradually,  and  disappear
almost  entirely after  a few minutes.   Then, if  we prevent it
again to breathe, we see the movements produced again.   This
experiment may be  repeated many times, with the same  result,
on the same animal.
   We are certainly entitled to conclude that there is an exciting
cause of contractions, developed during asphyxia, and that it is
neither the cold nor the atmospheric  air which produces in all
cases the movements of the bowels after the opening of the abdo-
men.   We may draw the same conclusions from another  experi-
ment.   If we put a tie around the trachea of a living animal,
immediately after expiration, we  may see and feel violent move-
ments taking place in the bowels, although the abdomen is not 
112
opened.   It is in consequence of such movements  that there is
an expulsion of  faecal matters, after death, in man.  The urine
may be also expelled in these cases, in man and in animals, and
this expulsion takes place because the bladder contracts, and not,
as it is generally admitted, because the sphincter vesicae becomes
relaxed.
   Some physiologists have considered the cessation of the circula-
tion of the blood in the bowels as the cause of their movements,
after death, and they relate as a proof the fact that the section of
one of the arteries going to a part of the intestines, is followed by
contractions in the parts thus deprived of  circulation.   But no-
thing is explained by saying that the cause of the contraction is
in the absence of circulation.   As contractions require an  exci-
tation to be produced, what is the exciting  cause when the blood
does not circulate ?  After the section of an artery there is blood
remaining in the capillaries, and that blood, after a short time, be-
comes very rich in carbonic acid, and  then, if my theory is right,
contractions ought to be produced.   The result of the section of
one of the arteries is, therefore, in  accordance with my theory.
  Other facts may be adduced proving the influence  of black
blood and carbonic acid on the bowels.
  If black blood is injected in the arteries  of the small intestine
when its irritability is much diminished, movements are almost
immediately produced, but they do not last  long.   On the con-
trary, if red blood is injected, movements do  not appear immedi-
ately, and they are very strong  and  last long.  This action  of
red blood may be easily understood:  it increases the irritability
of the muscular layer of the bowels, as it does  for that of the
muscles of animal life, and when it has been changed into black
blood, it excites the muscular tissue  and produces  contraction.
The strength and the long  duration of the contraction in this
case depend on the  increase of irritability.  When, as in the
above  experiment, black blood  (containing a  great quantity of
carbonic acid, on account of the constant formation of that gas
in blood deprived of the contact of atmospheric air) is injected,
the irritability is not sensibly increased, but the excitation is con-
siderable and there is an almost immediate effect.
  If air is injected in the arteries of the bowels, soon after the
death of the animal, a part of the blood it contains is expelled, 
113
and we  find  that  the movements do not  last as  long as if the
blood had not been removed.
  When an animal is killed by haemorrhage, the intestine, as well
as all the other organs, contains more blood than usual, and then
its movements are not so strong, and last less than they do gene-
rally.
  When in a recently asphyxiated animal  the arteries and veins
of a part of  the bowels are divided, the movements of that part
become less strong and last less than those of the other parts of
the intestine.
   When the bowels of a recently asphyxiated animal are put
under a receiver containing carbonic acid, their  movements are
very much increased, but they do not last so long as when they
are in the atmosphere.
   When  they are put under a receiver  containing  hydrogen,
their movements  are very quickly  diminished in strength, and
they  last still less than when exposed to carbonic acid.
   When  they are put in oxygen,  their movements diminish a
little at first and soon after become  stronger, and they last much
longer  than usual.
   As a general conclusion about the apparently spontaneous con-
tractions which I  have described as  taking place  in paralyzed
muscles during life or after death,  I will  say that it seems that
black blood by its carbonic acid is the cause of these contractions.
When the nervous centres are still united with  the  contractile
tissues, we see, during agony or after death, stronger movements
generally than when they are separated.   The  action of black
blood on the nervous centres may be very great.  I have found
that  the  spinal cord, when  separated from the encephalon, may
be strongly excited by black blood.  If an animal is asphyxiated
after a transversal and complete division of its spinal marrow in
the dorsal region, we see convulsions  taking place in the poste-
rior limbs, and they are  nearly as  strong as when the nervous
centers have not been injured.  The  excitation on the  spinal
marrow is considerable enough to produce an   erection  of  the
penis.*
   * Almost all, if not all, the secretions  of the body are increased during
asphyxia: bile, (as shown by Professor  Bouisson,) saliva, tears,  gastric,
pancreatic and intestinal juices,  and also liver-sugar, etc., are produced in 
Ill
  XXXIV__ON  THE CAUSE OF THE BEATINGS OF THE HEART.
  The cause of the rhythmical movements of the heart has been
heretofore unknown.   I believe  I have discovered it.
  Before  exposing my theory and  the  facts upon  which it is
grounded, I will show that the  theories  put forward until now
are not correct.
  There are  three  theories only which  are  worthy of examina-
tion : 1st, that of  Haller; 2d,  that  of  Carpenter;  3d,  that of
Budge, Schiff, and  others.
  Haller  has been very near the truth in  admitting that the
beatings of  the heart were excited by the blood.  His error has
been  an error loci.   He  thought that  the  blood acted in the
cavities of the heart.  It is  not so; and it is known that the
heart may continue to beat after all the blood has  been drawn
out of its cavities.
  The doctrine of Carpenter* is a very simple and  remarkable
one.   He believes that the muscular  fibres may act without hav-
ing been excited.   A muscle,  says he, may be compared to  the
electric jar, and become so charged with motility, (or motor force,)
as to  execute spontaneous contractions; and elsewhere, " It is not
very difficult to conceive that the ordinary rhythmical movements
of the heart may be due to a simple excess of this motility, which
is continually being supplied  by the  nutritive operations, and is
as constantly discharging itself in contractile action." Carpenter
believes that the reason for which the heart presents spontaneous
contractions while the other muscles do not, (at  least ordinarily,)
is, that there is a higher  degree of motility in the heart.   He
considers  as very important  the facts I have  discovered, that
many other muscles  besides the heart  may present rhythmical
movements.   He thinks that these facts show there is a tendency
to rhythmical movements in the muscles themselves, altogether

greater quantity then than usual.  I believe that this increase results from
the  excitation of the nervous system, and, in some  measure,  perhaps, from
a direct action of black blood on the capillaries of the glands.  The urinary
secretion may also be changed in asphyxia, and not only then the urine
may contain sugar, as Alvaro Reynoso has found, but also albumen.
  * See his Principles of Human  Physiology, American  edition,  by F. G.
Smith.  Philadelphia, 1853.  pp. 130 to 132, 319, 325, and 471-72. 
115
independent of the  excitement  to action which  they receive
through the nervous system.
   The best ground for the hypothesis of Carpenter is that, ac-
cording to him, the  heart continues to beat, although it is not
exposed to any excitation in certain circumstances.   He says:
"When every source of  excitement is excluded, we  cannot but
perceive that these  actions take place with a spontaniety which
can  scarcely be accounted for in  any other way than by  con-
sidering them as expressions of the vital activity of the compo-
nent cells of these forms of muscular  tissue, which manifests it-
self  in this mode, when the developmental life of the cell has at-
tained its  maturity.  And this view is strikingly confirmed by
what we know of the origin and termination of these movements.
For  the action of the heart commences when, as yet, its contrac-
tile  parietes consist but  of an assemblage of ordinary-looking
cells, no proper muscular tissue being evolved, and no nervous
system being yet developed, from which the stimulus to the move-
ment can proceed; and it is impossible to assign any other cause
for  the movement under such circumstances, than the attributes
inherent in the tissues which perform it."
   The first thing to  be said against the view of Carpenter is, that
his  hypothesis is  not necessary; because it is possible to assign
another cause for  the movement of the heart under the circum-
stances he speaks of.  This will be proved hereafter.
   The doctrine of  Carpenter implies, that the degree  of irrita-
bility  (motility, motor  force, contractility,—never  mind  the
name) is  greater  in the heart than in the other  muscles which
have no spontaneous action.  This is not the case.  The degree
of irritability, as judged by its duration after death, is generally
greater in  the muscle of animal life, than in  the heart.  The ac-
cepted  sentence of  Haller,  Cor  ultimum moriens, generally,  is
not  true.
   If Carpenter was  right, we should see, during life, the appa-
rently spontaneous contractions which take place in all the  con-
tractile tissues  after death; because  their  irritability is  at  a
higher degree in the first, than in the  second case.  Besides, we
should not see  oxygen,  or red blood,  diminish the frequency of
the beatings of the heart; and black blood, or carbonic acid, in-
crease that frequency. 
116
  An experiment, consisting in the research of the influence of
vacuo on the heart, has been made by Tiedemann and by Dr.
S. W. Mitchell, and Dr. T. H. Bache, (see Dunglison's Physiol.,
vol. ii. p. 150.)  It seems to me that the result of this  experi-
ment is in  complete opposition  to the doctrine  of Carpenter.
These experimenters have found that the beatings of a heart were
speedily brought to a  stand by the exhaustion of the  air, and
that they were  renewed when it was re-admitted.  If the view
of the  eminent British  physiologist was right, we ought to  see
the heart continue to beat in vacuo about the same length of time
as it would in  hydrogen  or nitrogen, because its  irritability
cannot be suddenly diminished enough by the exhaustion of the
air.  In these gases the heart of a mammal may beat  for five or
ten minutes or more, and the right auricle may beat for hours ;
and  the heart of a frog may beat for one day.   It is much more
to account for the stopping of the heart's action in admitting that
the excitant of that action  is removed during the exhaustion of
the air.  John Reid had found that the heart of a frog had con-
tinued to beat in vacuo, but how long he does not say.*
  I  will relate hereafter many experiments of mine which are in
opposition to the theory of  Carpenter.
  It is one of the most important questions in physiology, whether
the nervous centres, the nerves, and the contractile tissues  are
able to act without  stimulation.   This question has not  been
yet  entirely treated by any physiologist.   I propose publishing
a special paper on the subject. I will merely say here that there
may be apparently spontaneous actions in the spinal cord, as well
as in the muscles.  For instance, very frequently, in a frog, after
the removal of the brain and the medulla oblongata, we may  see
strong movements  apparently spontaneous, but when we know
that the slightest excitation of the skin, or of any other very sen-

  * Art. Heart, in Todd's Cyclop., vol. ii. p. 611.  J. Reid says in the same
page, "We ought to be more cautious in admitting the existence of this in-
nate  moving power, since it is  in opposition to a well known law in the
animal economy, that though the various tissues of an organised body are
endowed with certain vital properties, yet the application of certain exter-
nal and  internal stimuli is necessary to produce their manifestations of
activity.  In  fact  it is from the action and reaction of these tissues  and
excitants upon each other that the phenomena of life result." 
117
sitive part, may excite the spinal  cord, and produce a  reflex ac-
tion, we are authorised to consider all the movements taking place
as reflex actions.  An excitation  may have  come to the spinal
marrow from the bladder,  from the bowels,  from the lungs, (in
which worms are almost always found in  the cold  seasons, i. e.
at the time these phenomena are generally observed,) etc.
   As to  the spontaneity of action in muscles, I have  tried  to
prove ia a preceding article that  it is a mere  and false appear-
ance.*   I will prove hereafter  that the cause of the apparently
spontaneous contractions of the heart, is the  same as that  of the
like contractions in other contractile tissues.
   The physiologists who maintain that the beatings of the heart

   *  Carpenter says that the action  of the  uterus, as it shows itself, " not
merely in the final parturient effort, but in local contractions that frequently
occur during the  latter months of gestation, (simulating the movements of
 the  foetus,) are more  satisfactorily accounted for by considering them as a
 discharge of accumulated power, than  in any other mode."  I will try to
prove  elsewhere  that for the uterus, as well as for any other contractile
 tisue, there is no  spontaneous action.  The  uterus,  in pregnancy, becomes
 more and more irritable every day,  and when its irritability has arrived at
 a very high degree, then the  slight excitation  produced by  the carbonic
 acid normally contained in the blood is sufficient to put it in action. When
 the contractions have begun, they are very much increased by a reflex ac-
 tion.  Every contraction is accompanied by a  galvanic discharge on  the
 nerves in the neighborhood of the muscular fibres which contract,  and the
 sensitive nerves  being thus excited, it results,  1st, that a  pain is felt, the
 degree of which  is in  proportion  to the degree of any contraction,  and
 therefore with the degree of galvanic discharge ;f 2d, that the spinal mar-
 row is excited, and produces  reflex movements in the uterus.  Now, the
 more these reflex contractions are  energetic, the more they arc induced to
 take place again, on  account of the galvanic discharge which accompanies
 them.   So that there would be a constant  increase in the  intensity of the
 contractions  if  there  were not four limits to them.   1st,  there  is no
 galvanic discharge when  the muscular fibres  are contracted;  it is  only
 at  the time they are contracting that  this  discharge takes place; 2d, the
 primitive cause of contraction, the excitation of the muscular tissue, by car-
 bonic acid, diminishes much during the contraction, because the caliber of
 the small blood-vessels is  much diminished, and the blood expelled from
 them ; 3d, every contraction of the  uterus diminishes the degree of its irri-
 tability ; 4th, the reflex power of the spinal cord becomes exhausted, or at
 least diminished.
   t  8ee, on this subject, my paper in the Comptes rendus de la Societe de Bologue, en. 1850,'t. ii.
 p. 172. 
118
 depend  on the nervous system, appear to me to be greatly mis-
 taken.  They make a confusion between two things, greatly dis-
 tinct, one from the other:  they conclude  from the fact that the
 nervous system is able to act on the heart, that its influence is
 necessary.  It is the same kind of mistake which is so frequently
 made as to the influence of the nervous system on nutrition, on
 secretions, and on  animal heat; because that system is able to
 act upon these functions, it is concluded that its influence  is ne-
 cessary.
   The first argument to be adduced against the writers who ad-
 mit,  as  necessary,  the influence of the nervous  system on  the
 heart, is, that  they change  only the ground of the difficulty in
 doing so. Instead of having to explain why the heart acts rhyth-
 mically, they have to explain why the nervous system acts rhyth-
 mically on  the heart.  Not  only they have not explained this
 rhythmic action of the nervous system, but, as far as I know,
 they appear not to have been aware that this was to be explained.
   The second reason  I will  mention,  is the fact, so well  esta-
 blised by my friend Professor Lebert, that, in embryos, the  heart
 beats when it  is merely composed of cells, and when the nervous
 system has not yet appeared
   A third reason is, that, either in  monsters, or in animals ope-
 rated on by physiologists, there has been a long persistence of the
 beatings of the heart when a part of the cerebro-spinal centre did
 not exist, or had been removed.  Any  part may be in that  case,
 even the medulla oblongata, as I have discovered.  (See Art. xvi.
 p. 40.)
   In  opposition to the idea that the  beatings of the heart depend
 on the microscopical ganglia existing in that organ, I will say,
 that,  besides the fact that the heart beats in embryos before the
 nervous system exists, and besides the improbability that such a
 small amount  of nervous matter should have so  great a power,
 there  are  two good  reasons against  this strange theory:__
 1. There have  been found no ganglia, large or microscopical, in
the auricles, in the sinuses of the pulmonary veins, or  in  those
veins.  All these parts, nevertheless, may continue to beat a long
while, (even for hours,) after  they have been separated from the
ventricles where are the microscopic ganglia.   2.  Rhythmical
movements may exist in a great many other muscular parts of the 
119
body, where there is no microscopical ganglion, and where these
parts have ceased to be under the influence of the nervous centres.
  The three theories which I have examined being unable to ex-
plain the beatings of the heart, I will now expose my theory,
and  discuss the three following questions:—1.  What is the exci-
tant which puts the heart in action ?  2. Does that excitant act
rhythmically ?  3. Does that excitant  act together directly on
the muscular fibres of the heart, and on the nervous system; or
does it act only on the muscular fibres ?
  After having solved these three questions, I will examine the
objections which might be made to the doctrine I propose.
  1. What is the excitant which puts the heart in action f
   I believe that the beatings  of the heart are excited by a prin-
ciple existing in the blood, and that carbonic acid is that princi-
ple.  This view is grounded on the following facts:
   a. When we prevent a warm blooded animal from breathing, the
beatings of the heart become more frequent than before, for about
one or two minutes.   It is not on account  of the emotion alone
that it  is so, because the same effect is produced when we as-
phyxiate suddenly an animal which has entirely lost his power
of having emotions, in consequence of the action of chloroform.
   b. Many times I have found,  on myself and on one of my
friends, that the beatings of the heart  are rendered more active
during asphyxia.  We bold  our  breath for about three quar-
ters of a minute, and during the last  fifteen seconds the heart
beats from two to four (in one case five) minutes more than when
the respiration was free.  We have made  the experiment in the
 sitting position, avoiding any movement of the body in all the
 cases.
   c. John Reid has discovered that when any hemadynamometer is
 put in the femoral artery of a dog, the mercury rises in the in-
 strument if the animal is asphyxiated, and about one minute after
 the respiration has been stopped.   The same result has been ob-
 tained in twenty experiments.   It seems to  me that  this fact
 proves that the contractions of the heart become more energetic
 during asphyxia.  John Reid attributes the  result  he has obtained
 to some difficulty that black blood seems to have in passing through
 the capillaries of the different parts of the body.  I do not deny
 that there is such a difficulty; but I think that the great reason 
120
of the ascension of mercury in the hemadynamometer is, the in-
crease in the force of the heart.   A simple experiment proves
that I am right.   I adapt the hemadynamometer to the aorta in
the abdominal cavity, and then I open quickly the chest,  and I
put a ligature to the brachial and carotid arteries.  About three
quarters of a minute after  opening the chest, and about  half
a minute after the ligature has been put on the arteries of the
head  and arms, the mercury rises notably in the instrument;
sometimes the elevation is as considerable as two inches.   It re-
sults from this experiment, that the heart beats more strongly in
asphyxia about one minute after its beginning.
   d.  Woodall, a most intelligent and accurate observer, says Dr.
Martin Paine, (see Med. and Physiol. Comment., t. ii. p. 49,)
states, that the best remedy for syncope is to obstruct respiration
entirely  by momentarily confining the nose and  mouth.   If  this
be true, it is in perfect accordance with my view, that, during as-
phyxia, the normal cause of the beating of the heart increases in
the blood.
  e. If a frog is put under a receiver containing pure oxygen, at
a temperature of  40 or 50° Fahr. (4, 5, or 10 Cent.) after its
heart has been laid bare and its central nervous system destroyed,
we  see the  heart  beat for a very long time, (one, two, or three
days.)  On the  contrary, if, at the  same temperature, another
frog, deprived also of the central nervous system, is put in car-
bonic acid gas, the heart beats very quickly at first,  but it soon
ceases to beat, (in  one or two hours only, sometimes, and for the
most about half a day.)
  /. All the causes which increase the formation of carbonic acid
gas in the body, increases the frequency of beatings of the heart.
  g. If we inject the serum of blood into the arteries of the heart,
so as to expel as completely as possible the blood contained  in the
capillaries of this  organ, and if then we remove the blood from
the cavities of the  heart, we find that its beatings are, at once
almost entirely suspended, and that they are completely stopped
in a very short time, (from one to eight minutes.)  The muscu-
lar  irritability is not destroyed in this organ; it does not beat
because its excitant has  been removed.
  h. I have found that  when the heart of a young animal is put
in hydrogen, its beatings hardly change at first, but they stop in 
121
a very short time.  When it is put in carbonic acid gas, its beat-
ings are, at first,  increased in frequency and strength;  but they
very soon are stopped.   When it is  put in oxygen, its beatings
are slowly increased  in  frequency and strength,  and they last
very long.
  i. On newly-born  cats and  dogs,  before the occlusion of the
ductus arteriosus, I open the chest and put a ligature on the ar-
teries going to the head and fore limbs, and on the aorta imme-
diately after the origin of the ductus arteriosus. Then the blood,
expelled from the right ventricle, is sent to the  lungs, from  which
it comes to the left auricle, and  afterwards to  the left ventricle.
From there it is sent into the only part of the aorta remaining ac-
cessible, and thence it goes into the cardiac arteries, and into the
pulmonary artery, through the ductus arteriosus, (a direction which
is the reverse of the normal direction in that duct.)  By the cardiac
veins the blood arrives again in the right side of the heart. The
circulation from the heart to the lungs, and vice versa, continues
very well.   I have found, that if hydrogen is insufflated into the
lungs, the  beatings of the heart are not much changed at first,
but they go on diminishing, and they disappear in a short time.
When an injection is made with carbonic acid, the beatings of the
heart are quickly increased in frequency and strength;  but they
are stopped after a short time.  When  oxygen is  insufflated, the
beatings of the heart become slowly more frequent, and they re-
main quick and  strong  for a long time.   (I have once, by such
insufflation of oxygen, maintained beating for eleven hours  in the
heart of a  young cat.)
  I believe that  these facts prove that black blood, by its car-
bonic acid, is  an  excitant of the beatings of the heart.   If, nowT,
we  adduce to these facts all those I have related  in a preceding
article,  on  the apparently  spontaneous contractions in all the
contractile tissues of the body,  we shall have a  very considerable
number of facts, proving that, during asphyxia, there  is an ac-
cumulation in the blood of the principle which causes these con-
tractions.  I believe that it is almost impossible to deny that this
principle is the carbonic acid gas.
  Before trying to show that  what  takes place in asphyxia in
the heart is only an exaggeration of what normally exists in that
organ, I will treat the two remaining of the three questions  I
                             10 
122
 havo announced I would endeavor to solve, as regards the exci-
 tant of the heart's action.
   2.  Why does that excitant act rhythmically f
   I believe it is easy to  explain why the agent of excitation of
 the heart* produces rhythmical contractions.  I will suppose, first,
 that the action is permanent.  A part of the heart, ventricles, or
 auricles, being dilated, receives an excitation in all its fibres si-
 multaneously, and a  contraction is produced.  But, according to
 the  well-known law of Schwann, the exciting cause which is able
 to give the impulse when the muscular fibres are long, is not able
 to maintain the contraction when the fibres have been shortened.
 Then, on account of this insufficiency of power of the cause of the
 contraction, a dilatation ensues.  We  may present the fact in
 other words, and say that the resistance to the contraction origi-
 nating from  the displacement of the constitutive matter of the
 contractile tissues, increases in proportion to the shortening of
 the  fibres; and that after the fibres have contracted under the
 impulse of  the  exciting cause, although this eause continues to
 act, a dilatation is produced by the force belonging to that re-
 sistance, which is nothing but elasticity.  If the cause of the con-
 traction of the heart  was a considerable one, then we should see
 a permanent contraction ; and it is so when we apply galvanism—
 the  elasticity, then, is not powerful enough to produce dilatation.
 On the contrary, with a weak exciting eause, like earbonic acid,
 the  result  ought  to  be different.   When  that  cause  has more
 power, as  in  asphyxia, the shortening of the fibres takes place
 quicker, and is more  considerable; and  even then it is not suffi-
 cient to maintain  contraction, the tendency to dilatation being
 also increased.
   I ought to  say, that the  excitant cause of the contractions is
 not  always at the same degree of power.  The small blood-vessels
 and the capillaries being compressed during the muscular con-
 tractions,  there is a  diminution of excitation during that time.
 This should be sufficient to explain the alternate contractions
 and dilatations.  But such a diminution in the  caliber ought to
 be very little, if even  it exists in certain organs,  (the heart when
 composed of cells, for instance.)

  * What I will say here for the heart, might be said for all the contractile
 tissues, presenting apparently spontaneous rhythmical  contractions, as the
cilia, for instance. 
123
  I come now to the third  question about  the  excitant of the
heart—
  3. Does that excitant act together on the  muscular fibres and
on the nerves of  the heart,  or  does it  act only on the muscular
fibres ?
  I believe it ought to act also on the nerves; but I cannot prove
it otherwise than by saying, that all the agents of excitation that
we  know to act on  the muscular fibres, are able to act on the
nerves.
  There are many things to be said besides the above facts and
reasoning, to prove the  truth of the doctrine I propose.  I will
expose some of them.
  The following question might be made:
   How is it that the heart is the only muscle containing striated
fibres, which presents normally rhythmical movements ?
   The answer to this question appears to be very simple.   The
intensity of the stimuli,  the degree of irritability, and the resist-
ance which a muscle has to overcome when it contracts, are three
elements which we ought not to lose sight  of when we examine
the difference of contractions between two muscles.  Suppose the
heart possessing  the same degree  of irritability as another mus-
cle : if the stimulus is the same, and the resistance the same also,
for  the heart and for the other muscle, there will be the same
 effects.   But if the  stimulus is more considerable in the  heart
 than in the other muscle, and if the resistance to be overcome is
 less for  the  heart, then with  the same degree of irritability in
 both parts, and even with less irritability in the  heart than in the
 other  muscle, we will see a movement in the heart, and not m
 that other  muscle.  Now a simple examination of the vessels of
 the heart, proves that they contain more blood, and consequently
 more  stimulus, than the other striated muscles.  Besides, as the
 heart is not inserted into heavy bones to be moved, it has less re-
 sistance  to overcome when it  has not to circulate the blood, as
 after  death, or when it is out  of the chest, than the muscles of
 animal life.  Some muscles in the face and  the diaphragm, being
 almost without an external resistance, when their contractions
 do not go so far, it results that they are moved much more easily
 after death, than the muscles  of  the limbs.   In consequence of
 these  views, I believe that, although there is in the blood-vessels 
124
of all the muscles of the  body a principle which is an exciting
cause  of  contractions, there are no contractions produced, be-
cause the quantity of that principle is not sufficient, or because
the resistance to contractions in many muscles is greater than in
the heart.
  I must, in conclusion, say, that I do  not advance my theory of
the rhythmical movements as  perfectly proved.   I believe it is
true, and that there are a great many facts which appear posi-
tively to prove it.   What I can assert is, that it is by far much
more in harmony with all the known facts, than the other theories. 
 
 
F£Bi o *6°,
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