THE

INSTITUTIONS

            OP
9
              J. FRED.  BLUMENBACH,

            Professor of Medicine in the University of Gottingen.

TRANSLATED FROM THE LATIN OF THE THIRD AND LAST
                          EDITION.
&upjplieti toitlj numerous an& e*ten£foe ,0ote£,
             JOHN  ELLIOTSON,  M. D.
Member of Jesus College, Cambridge; the Royal College of Physicians, London; the
   Medico-Chirurgical Society of London; Member, and formerly President of
               the Royal Medical Society of Edinburgh.
SECOND EDITION.
 Quseramus optima, nee protinus se offerentibus gaudeamus; adliibeatur judicium
                    inventis, dispositio probatis.
,."*"""*~ " "*— ""-•^                                    QuirUUian.

f\\Wl*C\
V^' CT^'^j/ VHILADELPHlA:  ^                 \

  BUi'MSBED BT  BENJAMIN WARMEH, AND FOB  SAti^AT* $Sf HO^$|Oll£/
               PHILADELPHIA, AMD IUCH3I0ND, VIRGIOT**—*. .. .~ - " "'
1817. 
 
THE
        TRANSLATOR'S PREFACE.

 A HE highly flattering manner in which the Edition which
I last year published of this work, was received, has both en-
couraged and compelled me this  year to prepare a second
Edition.

  The translation has been revised, all Blumenbach's referen-
ces inserted, and my own notes and references increased to a
considerable extent.  In the latter, the progress of Physiolo-
gical science since 1810, when the last Edition of Blumen-
bach's work was published, is detailed, and many points are
treated of at large which could not, consistently with Blumen-
bach's design, be more than briefly mentioned in the original.
The last note,—upon the characteristics and varieties of man-
kind, is an independent addition.

  No one can be more sensible than myself to the imperfec-
tions of my performance.  In excuse I must urge the prodi-
gious extent and variety of my subject, and the short period
allowed me through the rapid sale of the first Edition and
the importunities of my Bookseller for the second.

  No one will ever listen more readily to friendly criticism, or
more readily smile at and forgive the suggestions of ill nature.
Grafton Street, Bond Street
       Dec. 1816. 
THE  AUTHOR'S  PREFACE
       TO THE


LAST EDITION.
WHENEVER my booksellers have  informed me that a
new edition of any of my works was required, I have always
gladly  seized  the  opportunity  of  correcting inaccuracies,
arising either from carelessness or the imperfection of human
nature; of adding in some  places and altering in others ; in
short, of sending forth the production  of  my abilities in a
more finished state.

  In preparing  this  new edition of my Institutions of
Physiology for the  press,  the  same anxious wish has been
considerably heightened by the importance of the subject, and
by the  approbation evidently bestowed upon the last edition,
from its translation into our own ^language, into Spanish,
French, English, Dutch, and Russian,  not to mention other
proofs  of its  favourable reception.  I have endeavoured,
therefore, to enrich it not so much with  an addition of pages,
as of various matter; to  arrange the  heads in a more  natural
order j  and  to render the  whole as useful to  students as
possible.
September 10, 1810. 
THE AUTHOR'S PREFACE

               TO THE

        FIRST EDITION.
 1 he same  considerations  which led  Boerhaave, and after
him Haller, to  write their  Compendiums of Physiology, in-
duced the author to compose these Institutions.
  The former says, " that a teacher succeeds better in com-
menting upon his own thoughts, than upon a work  written
by  another:—that his doctrine will be clearer, and his lan-
guage generally animated," &c*
  The latter, " That although he formerly used Boerhaave's
work as a text-book,  he afterwards lectured upon one written
by  himself,  because, since  the time of Boerhaave, anatomy
has been so improved as to become almost a new science."f
  What Haller said  at that period respecting anatomy, will
be allowed to apply much more forcibly at  present to physi-
ology, by any one who considers the most important parts of
the  science,—-the principal  purpose of respiration,  animal
heat, digestion, the true nature and use of the bile, the func-
tion of generation, &c.
  More, therefore, must be ascribed to the age than to the
* Pref. to the Inatitut. Medic. Leyden. Fourth edition.
f Pref. to the Prim. tin. Physiol. Gottingen. First edition. 
VI                       PREFACE.
 author, if in these Institutions, after so many modern physi-
 ological  discoveries, he delivers doctrines more sound and
 natural than it was in the power of his most meritorious pre-
 decessors to deliver.
   Whatever he can claim as his own, whether really new or
 onry explained in a new manner, will be easily discovered by
 the learned  and impartial reader; especially from the notes,
 in which he has  treated some of these subjects rather more
 minutely than, in the text, was compatible with the concise-
 ness of his plan.
   He has been at great pains in arranging the subjects, so
 that rthe sections  might  succeed  naturally  and easily, and
 arise, as  it were, one out of another.
   He has not  quoted  a dry farrago of books,  but a select
 number,  in doing whi-ch, he has wished both to point out to
students  some  excellent authors not commonly  known, es-
pecially  those  who  have professedly treated on particular
branches of the subject, and to open, besides medical sources
of information, others not yet applied, he conceives, to Phy-
siology as they deserve.
   His grand object has been to deliver, in a faithful, concise,
and  intelligible manner, the principles of  a  science  inferior
in beauty, importance, and utility, to no part of medicine, if
 the words prefixed by the immortal  Galen to his Methodus
 Medendi, are, as they most certainly are, true,—" The mag-
nitude of a disease is in proportion to its deviation from the
healthy state; and the extent of this deviation can be ascer-
 tained by  him only who is  perfectly  acquainted with the
 healthy state." 
CONTENTS.
   •.EOT.                                         PAGE.
     I. Of the Living Human Body in general.......    1
    II. Of the Fluids in general, and particularly of
         the Blood.................................................    3
   III.  Of the Solids in general, and particularly of
         the Mucous Tela......................................   12
    IV.  Of the Vital Powers in general, and parti-
         cularly of Contracility..............................   16
     V.  Of the Mental  Faculties............................   29
   VI.  Of Health and Human Nature..................   32
   VII.  Of the Motion of the Blood.......................   49
  VIII.  Of Respiration and its principal Use .........   73
    IX.  Of Voice and Speech..................................   87
     X.  Of animal Heat...........................................   96
    XI.  Of the Cutaneous Perspiration...................  105
   XII.  Of the.Functions of the Nervous System in
         general......................................................  116
  XIII. Of the external Senses in general, and parti-
         cularly of Touch......................................  133
  XIV.  Of Taste.....................................................  136
   XV.  Of Smell.....................................................  139
  XVI.  Of Hearing.................................................  143
 XVII.  Of Sight.......................•..............................  147
XVIII.  Of the voluntary Motions..........................  161
  XIX.  Of Muscular Motion..................................  166
   XX.  Of Sleep......................................................  177
  XXI. Of Food and Hunger..................................  185 
VU1                     CONTENTS.
      6ECT.                                         PAGE.
    XXII. Of Mastication and Deglutition.................  193
   XXIII. Of Digestion...............................................  199
   XXIV. Of the Pancreatic Juice..............................  205
    XXV. Of the Bile.................................................  207
   XXVI. Of the Function of the Spleen...................  216
  XXVII. Of the Function of the Omentum..............  220
 XXVIII. Of the Function of the Intestines..............  223
   XXIX. Of the Function of the Absorbent System ..  231
    XXX. Of Sanguification........................................  240
   XXXI. Of Nutrition...............................................  243
  XXXII. Of the Secretions in general.......................  248
 XXXIII. Of the Fat..................................................  257
  XXXIV. Of the Urine..............................................  261
  XXXV. Of the general Differences between the Sexes  267
 XXXVI. Of the Genital Function of the Male .........  274
 XXXVII. Of  the  Genital  Function of the Female
            in general...............................................  298
XXXVIII. Of the  Menstrua «.....................................  307
  XXXIX. Of Conception and Pregnancy...................  311
      XL. Of the  Nisus Formativus........................  333
     XLL' Of Labour and its  Sequelae......................  340
    XLIJ. Of the  Milk  ...........................................  345
   XLII1. Of the Differences in the System before and
            after Birth.............................................  355
   XLIV. Of the  Growth, stationary Condition, and
            Decrease of the  System ..........................  363

  The translator's notes are annexed each to the section
to which its subject respectively belongs.
  The note on the characteristics and  varieties of man-
kind begins at................................................................ 376 
              THE

      INSTITUTIONS

               OF


PHYSIOLOGY.
                         SECT. I.

           OF THE  LIVING HUMAN BODY IN GENERAL.

   1.  In the living human body, regarded as a peculiar or-
ganization, there are three objects of consideration.*
   The materials of its subsistence, afforded by the fluids ;
   The structure of the solids, containing the fluids ;
   Lastly,  and  principally, the vital powers, by which  the
solids are  enabled  to  receive the influence of the  fluids—
to propel  the fluids—and  perform  various  other motions;
  * Thus, long ago, the author of the book, generally included among the
writings  of Hippocrates, Epidemic, VI. Sect. 8. § 19. said *' Those things
which contain, are contained, or moved in us with force, are to be consider-
ed."  This celebrated  passage gave origin to the excellent wurk ofAbr.
Kaau Boerhaave, entitled, " Impetum faciem dictum Hippocrati  per corpus
consentient    L. B.  1745.  8 vo.
                               B 
2              OF THE LIVING HUMAN BODY.

and which, as  they, in a certain sense, constitute the essence
of the living machine in general, so also  are of very different
orders :  some being common to animals  and  vegetables, and
some peculiar to animals, and intimately connected with the
mental faculties.
  2.  But  these  three, although really  distinct, and  there-
fore distinctly considered by us, are so closely related in the
living- system, (the phenomena, conditions, and laws of whose
functions, in the  healthy state, are the object of  physiology,)
that no one can be  contemplated, but in  its relation  to the
rest.
  For the  materials of the body, although originally fluid,
are naturally disposed to  become solid;  and, on the other
hand, the solids, besides having been formed  from the fluids,
abound, however dry they  may appear,  in various kinds of
fluid  constituents, both liquid  and aeriform : lastly, it  may
probably be affirmed that  no  fibril, during life,  is detitute
of vital power.
  3.  We shall now examine each of these separately;  and
first,   the  materials  afforded  by  the  fluids,  which  form
the fundamental and most  considerable portion of our bo-
dies.*
  * The great prepoHderance of the fluids is strikingly exemplified in an entire,
but perfectly dry mummy of an adult Guanclie, one of the orignal inhabitants
of the Island of Teneriffe.  It was sent to my anatomical museum by the il-
lustrious Banks ;, and though all its viscera and muscles are preserved, does
not exceed 7 l-21bs. in weight- 
OF THI.  1LUIDS-
SECT. II.
   OF THE FLUIDS IN  GENERAL, AND PARTICULARLY  OF THE
                          BLOOD.

   4.  The fluids of  the  body may be conveniently reduced
to three classes.
   A. The crude ; viz. the chyle, contained in the primae vise,
and destined to become blood ; also, matters absorbed on the
surface, and destined to be conveyed to the chyle.
   B.  The blood itself.
   C.  Those  secreted from the blood, whether inert and ex-
crementitious,  like the  urine ; or intended for certain pur-
poses in the economy : the latter may be permanently liquid,
as the bile—or disposed  to solidity, as the osseous and other
plastic juices.
   5.  Of the  first and third  of  these classes, we shall here-
after speak, in treating of chylosis, secretion, and the other
functions to which each  fluid appertains.   At present our
attention  shall  be devoted to the blood,* the chief and pri-
mary fluid__the vehicle  of those  successions of  oxygenous
(A) and carbonaceous particles, which cease only  with life—
the nourisher of the frame—the source of almost every fluid—
that into which the crude fluid is converted, and/row which
all the secretions are derived; and which, with  the excep-
tion of some exsangueous parts, as the epidermis, the arach-
  * J. Hunter's Treatise on the Blood, Inflammation, &c.  London, 1704,
4to. 
4,                       OF THE BLOOD.
noid, the amnion,  &c the virtreous substance of the  teeth,
the  body of the  chrystaline  lens,  &c. is universally  dif-
fused through the  system, in various  proportions, indeed,
according to the various natures of the  similar  parts,  to use
the language of the ancients,* v. c. abudantly in the muscles
and glands, sparingly in the tendons and cartilages.f
   6. The blood is a peculiar fluid, of a well known colour
and remarkable  odour; its taste  rather salt and nauseous j
its temperature about 96° of Fahrenheit;  glutinous to the
touch; its specific  gravity,  though different in  different in-
dividuals, may be generally estimated as 1050,   water being
1000:  when first drawn, and received into  a vessel, it exhi-
bits the following appearances.^
   7. At first,  especially  while  still  warm,   it   emits  a
vapour which  has of  late  been  denominated an  animal
gas, and  shewn to consist of hydrogen  and  carbon, sus-
pended by  caloric.§  This,  if collected,  forms drops, re-
  * They divided the body into similar or homogeneous parts as the bones,
cartilages, muscles, tendons, &c. ; and dissimilar, composed of the similar,
as the head, trunk, limbs, &c.
  f Physiologists have variously est imated the quantity of the blood in awejl
formed adult.  Allen, Mullen, and Albeildgaard, make it scarcely more
than 8 pounds ; Borelli, 20 ; Haller, 30; Hamberger, 80; J. Keil, 100.  The
former are evidently nearer the truth.
  J J. Martin Butt.  De spontanea sanguinis separatione.  Edinb. 1760, 8vo.
reprinted in Standif'ort's  Thesaurus, vol. ii.  J. H. L. Bader.  Experimenta
circa sanguinem. Argent.  1788, 8vo.
  § The elements of aeriform fluids of course exist in the blood; that they are
not, however, in the elastic state, as so many physiologists formerly believed,
was clearly shewn in some experiments made by me during the year 1812,
upon other mamalia.  1 found that a small portion of the purest air infused
into the jugular vein, excited palpitations, drowsiness, convulsions ; and if
the quantity was rather increased, even death ensued.  I have detailed these 
OF THE BLOOD.
sembling dew  of a  watery  nature, but  endowed  with a
nidorous odour,  most remarkable  in the  blood of carnivo-
rous  animals,  peculiar and truly  animal.   Much of  this
watery liquor still remains united with  the other parts of the
blood.
   8.  In  the mean  time  the  blood, when  its temperature
has fallen  to about  78°, begins to  separate  into two  por-
tions.  A  coagulum is formed, from  the surface of which,
as  it were,  exudes a  fluid of  a  yellowish slighdy  red
colour,  denominated serum:  the  more  abundantly  this
exudes,  the  greater is  the contraction  of  the glutinous
coagulum, which has  received  the  appellations  of crassa-
mentum ; and,  from some resemblance  to the liver, in colour
and texture, of hepar  sanguineum;  of placenta; and from
the circumstance of its being  surrounded by the serum, of
insula.
   9.  The  crassamentum  may,  by  agitation, or repeated
ablution, be  easily  separated  into  two  constituent parts:
into  the cruor, which imparted to  the  blood  its purple
colour,  and into the lymph, which on washing  is forsaken
by the  cruor, and called,  from  its-greater solidity, the
basis  of the  crassamentum.   The  stronger  affinity of the
cruor for  the  lymph than for the serum, is proved by the
necessity of violence to effect their disunion (B).  By the
 removal of the cruor the lymph becomes gradually paler, till
 it is at length  merely a white tenacious coagulum.
   10. Besides the watery fluid  first  mentioned, there are
 the three constituents  of  the  blood, viz.  the  serum,  the
 cruor, and  the lymph:  we shall presently  treat  of  each
experiments in the .Medic. Biblioth. vol. i. 177.  The illustrious Bichat ob-
served the same effects in his experiments.  Journal de Saute, &c. tie Bor-
deait.v.  T. 11.61.
\ 
6                     OF THE BLOOD.
more particularly.  These,  however, while  recent,  and in
possession of their native heat,  are intimately mixed, and
form an  equable, homogeneous fluid.  Their  relative pro-
portion is astonishingly diversified, according to age, tem-
perament, diet,  and similar circumstances, which constitute
the peculiar health of each individual.
   11. The serum is a  fluid, sui  generis;  the chief cause
of the viscidity  of the  blood,  and  easily separable  by  art
into  different   constituent principles.   If  subjected  to a
temperature  of  150o  Fahr. a  portion  is converted  into a
white  scissile  substance,  resembling boiled albumen:  the
rest exhibits besides the  watery fluid  so often  mentioned,
a  turbid  fluid of  a gelatinous, or  rather mucous*  nature,
which on cooling  appears  a  tremulous  coagulum.   The
serum is  remarkable for  the quantity of soda (mineral  al-
kali) which it contains. (C)
   12. The cruor is marked by  many irregularities,  both in
the  colour  and  the  figure  of  its particles.   It  consists of
globules,  which  in  recent blood  are of  a  constant  form
and  size, and  said to  be ^Vs  of an  inch  in  diameter.
Their form, indeed, has been  a  subject of dispute ;  but I
am  disposed to  consider  it  as  much  more  simple than
some writers of great  celebrity  have  imagined.   I  have
always  found it  globular,  and  could  never  discover the
lenticular shape, which some  have asserted that they  re-
marked.
   It has been  likewise advanced, that the globules  change
their form, while passing through  a vessel of very small
capacity;  that,  from  being spherical,  they  become oval ;
and  when they have emerged  into a vessel  of larger area,
  *.J. Bostock, in  The  Medico-Chirurgical Transactions, published by the
Medical and Chirurgical Society of London, vol. i. 1809. p. 46.
0 
OF THE BLOOD.
7
that they again resume their globular shape.*  This, although
I would by no means deny it, I cannot conceive to  occur du-
ring the tranquil and healthy motion of the blood, but should
refer it to a spasm of the small vessels
   Their  globular   figure can be  seen  in a  living animal
only,  or  in  blood  very  recently  drawn:  for  they  are
soon   unobservable,   becoming  a  shapeless  mass  which
resembles   serum  in  every circumstance,  excepting  co-
lour.
   Their colour is red, and from it is derived  the  colour of
the blood.  In intensity it varies infinitely ; paler in  animals
which have  been poorly  nourished  or have suffered from
haemorrhage;  more florid, when oxygenized,f (or rendered
arterial,  to  use  the  common   phrase)  by  exposure  ei-
ther  to  atmospheric  air,   or   more especially,  oxygen;
darker  when  carbonized  (in  common  language  render-
ed venous)  by exposure to carbonic  acid  gas,  or to hydro-
gen4   The  redness is most probably to be  ascribed to the
  * G. Ohr. Reichel, De Sanguine ejusque motu experimenta.  Lips. 1767.
4to. p. 27, fig. 3, g. g.

  f Unwilling as I am to follow the example of those, who especially in mo-
dern times, delight in changing  scientific terms, I cannot but think that the
word, oxygenized and carbonized may be advantageously substituted for arte-
rial and venous ;  because arterial blood is contained in some vessels called
veins, v. c.  the pulmonary and umbilical, while, on the other hand, venous
blood is contained in  the pulmonary and umbilical arteries. In the same man-
ner the veins of the chorion in the incubated egg contain arterial, the arte-
ries venous, blood, to use these expressions in their common acceptation.

  t Consult among  others whom we shall recommend in the chapter on
respiration, Chr. Girtannerin the Journal de Phjsujue, August 1790. 
8
OF THE BLOOD.
oxide of iron,* the quantity of which, however, is so minute,
that it has been most variously estimated (D).
   14.  The last constituent principle of  the blood to  be no-
ticed,  is  the  plastic lymph, formerly  confounded with the
serum.  This has been called the basis of the crassamentum,
the glutinous part, the  fibre or  fibrous  matter of the blood,
and, like the caseous part of milk, and the gluten of vegeta-
bles, been discovered by late  analysis to abound in carbon
and azote (E).
   15.  It is  properly denomiated plastic, because it affords
the chief materials from which the similar parts, especially
the muscles, are immediately produced ; nourishes the body
throughout life, repairs wounds  and  fractures  in  an ex-
traordinary manner,  fills  up  the  arese  of  large  divided
blood vessels, and forms those  concretions which accompany
inflammations!,  and  that remarkable  decidous  membrane
found  in the  recently impregnated uterus for the attachment
of the  ovum.
   16.  Thus much have we  said,  respecting  the constituent
parts and nature  of the  blood, the most important fluid of
the  animal  machine,—a fluid,  which excites  the heart  to
  Fourcroy in the Annates de Chemie, T. vij.
  Hossenfratz, ibidem. T. ix.
  J. Ferd. H. Autenreith, Experimenta et observata de sanguine proesertim
venoso. Stuttg. 1792, 4to.

  * By Will. C Wells, Philos. Trans. 1797, the redness of the blood in gene-
raf is rather ascribed to the peculiar fabric of the globules, and its various de-
grees and changes simply to the reflection of light.
  f Such are those spurious membranes  found  exuded on the surface of in-
flamed viscera, v. c. those cellular connections between the lungs and pleura
after peripneumony, and the tubes  observed within the bronchia after
croup;such also are thoseartificialonescalled.aftertheirinventcr, Ruyschian,
and made by stirring fresh blood about with a stick 
OF THE BLOOD.
9
contraction, which distributes oxygen to every  part, and
conveys  the carbon to the excretory vessels, giving rise,
by this  change, to animal heat;  which originally supplies
the materials  of the solids,  and  afterwards  their nourish-
ment ; from which  all the fluids,  with  the  exception  of
the crude (4.) are secreted and derived.  Of the multifa-
rious  importance of the blood, we  shall  speak particularly
hereafter.
                       NOTES.

   (A) The blood  is not at present believed to absorb any
oxygen during respiration.  See note (C) to Sect. viii.
   (B) The red  particles, or cruor, are merely suspended
in the serum,  as  Leeuwenhoek and  Hartsoeker  long since
proved,  for if, when  separated,  they  are  triturated  in
serum, part of them  is taken up, and  the serum assumes a
red colour ; but if the fluid is allowed to settle in a cylin-
drical glass,  they slowly  precipitate   themselves  to the
bottom,  and the  serum  above  becomes clear, as  before.
The  serum  easily  separates  on  the   coagulation  of the
lymph;  the colouring part does  not  fall  to  the bottom
before the  lymph  coagulating envelopes it and  prevents
its  separation  :  but if  the  lymph  coagulate slowly> as  in
the phlogistic diathesis, the  greater  specific gravity of the
cruor  detaches  it very   considerably  from  the  lymph,
which remains  colourless   above,  constituting  what  is
called the inflammatory  coat,  crust or buff.   Berzelius
even  believes  the lymph to be in a state of solution in the
serum, while  the  cruor is simply  suspended in this solu-
                           C 
I
10                     OF  THE BLOOD.

tion, but the separation of  the serum in dropsy,  vesication,
&c. led  Mr. Hunter to a different conclusion.   View of the
present State  and Progress of Animal Chymistry by  Jons
Jacob  Berzelius, M. D. &c.  Translated by Dr. Brunnmark,
1813,  p. 23.  Hunter On the Blood, &c  4to. p. 18.
   (C)  The coagulable part of serum is albumen ; that which
remains fluid  is called  serosity,—a name given it by Cullen,
and contains no jelly, as  the French chymists asserted, but
an animal matter  different from  both  jelly and albumen,
with a minute  portion of albumen and fibrin, a little free
soda,  muriate, lactate,* and phosphate of soda, and muriate
of potash, with T9^j- of water.f
   (D) It has been generally supposed  that  iron existed in
the red particles of  the blood as a subphosphate.  Berzelius
informs us that serum, although  able  to dissolve a  small
portion of the oxydes, not indeed of the phosphates of iron,
does not acquire a red colour by  their addition ;  and that he
has never  discovered iron nor  lime in the entire blood, al-
 though both are so  abundant in its ashes ; and concludes that
the blood  contains  the  elements of phosphate of iron  and
of lime, and  of carbonate of lime, and also of phosphate of
magnesia,  united in a manner different from their combina-
tion in the salts.
   (E)  Oxygen and  hydrogen  also  exist  in  fibrin.   The
 fibrin, albumen and  colouring  matter afford,  on  decom-
 postion,  the  same  saline  and gaseous  products.  Berzelius
  * Berzelius discovers lactic acid free or combined in all animal fluids. It
was first noticed by Scheele, but is generally regarded as a combination of
acetous acid with animal matter.
  ■f- See Dr. Bostock's papers in the  first, second, and fourth volumes of
Tlw Medico Chirurgical Transactions, and Berzelius in the third. 
OF THE BLOOD.
views them all three as modifications of the same substance.
Albumen has a greater proportion of oxygen than fibrin, and
has sulphur for :i constituent part, which  consequently can-
not be detected  while  the  albumen is entire, any more than
the iron while the cruor is entire.   The chief differences be-
tween the colouring matter and fibrin are colour ; the sponta-
neous coagulation of fibrin at all temperatures, while the co-
louring matter may be dried without losing its solu' »ility in wa-
ter, and becomes insoluble only at a certain temperature ; 'and
the peculiarity  of the latter, of not diminishing in volume,
like fibrin, during exsiccation.—Berzelim, 1. c. 
12
OF THE SOLIDS.
                        SECT.  III.

  OF THE SOLIDS IN GENERAL, AND OK THE MUCOUS WEB IN l'AB'l '
                          CULAR.

   17.  The solids* are derived from  the fluids-   In the first
rudiments of  the gelatinous  embryo, they gradually com-
mence  in  their respective  situations, and differ infinitely in
their degreesf of cohesion,  from  the  soft  and almost pulpy
medullary matter of the  brain, to  the vitreous substance of
the corona of the teeth.
   18.  Besides the gelatinous  (ll) and glutinous (15) parts
of the solids, earth enters more or less into their composition,
and is principally  lime  united with  phosphoric acid.  The
bones  possess   this  in  the  greatest  abundance, particu-
larly in advanced  age, whereas  in  childhood the gelatinous
matter abounds.
   19.  With  respect to  texture, a  great  part  of the  solids
consist of fibres  more or less parallel.   This  may  be  ob-
served in  the bones,  especially  of foetuses,:}:  in  the mus-
  • Hier. Dav. Gaubius' Spec, exhibens ideam generalem  solidarum c. h. parti-
um.  Lugd. Bat. 1725,4to.

  ■j- Abr. Kaau Boerhaave, on the cohesion of the'solids in the animal body, in
the JVw. Comm. Acad. Petropolit. T. iv. p. 343, sq.

   % The parallel and reticulated bony fibres are most striking in the radiated
margins of the flat bones, as we find these in young heads much enlarged by
hydrocephalus.  I have, in'my museum, a preparation of this kind,  where, in
the sphenoid angles of the parietal bones, the fibres are  an inch  or two in
length, distinct and delicate. The hardest parts, the bony and vitreous por-
tions of die teeth, exhibit a structure similar to that which in the zpolite, ma
lachite-, hematite, 5cc. all mineralogists call fibrous. 
OF THE  MUCOUS WEB.
1.)
cles, tendons, ligaments, aponeuroses, and  in  certain mem-
branes, as the dura mater, Sec.
   20.  In other parts no fibres can  be  discovered, but  the
texture is peculiar,  called parenchyma, from  the time  of
Erasistratus,  and  differing  in  different viscera,  especially
the secreting,—of one kind in  the liver, of another  in  the
kidneys.
   21.  But in all the structures, whether fibrous  or  paren-
chymatous, there  is  interwoven  a   general  mucous  web,*
commonly but improperly styled  cellular, because it  rather
is continuous,  equal, tenacious,  ductile, sub-pellucid, and
glutinous.f  By handling, it is easily converted into a cellu-"
lar and vesicular membrane, and demands a  place  among
the most important and remarkable  constituents  of the  bo-
dy. (A.)
   22.  For, in the first place,  many  solid parts,  v. c. most
membranes and  cartilages, may  by long  continued  mace-
ration  be resolved into it  alone.   With some it  is so inti-
mately united,  as to  afford a receptacle  and support  for
other  constituents:  v. c.  the  hardest  bones  consisted  at
first of  cartilage,  which was  originally condensed mucous
membrane; but  since become distended by the effusion  of
bony  matter into its substance, which is rendered more  lax
and cellular.   In fact, it is universally present  in  the  solids,
if we  except the  epidermis, nails,  and hairs, and the  vi-
treous exterior of the corona of the teeth, in  which  I have
never been able  to discover  it  by employing the strongest
acid.
  * Dav. Chr. Schobinger (Pnes. Hallero) De tele Celluloses in fabrica c. h.
dignitate, Gotting. 1748, 4to. Sam. Chr. Lucae at  the end of his Observ.
Anatom. circa nervos arterias adeuntes.  Francof. 1810, 4to.

  f Casp. Fr. Wolff, in the Nov. Act. Petropol. T, vi. p. 259. 
14                OF THE MUGOUS WEB.
   23. To the muscles and membranes especially it serves for
 separation from other parts ;  to the vessels  and  nerves for
 support; and to every part it acts as the common medium of
 connection.
   24.  From these facts, two inferences may be drawn. First:
 That this membrane is  so fundamental a  constituent of our
 structure, that,  were every other  part removed, the  body
 would still retain its form.
   Secondly : That it forms a  connection between all parts of
 the system,  however different  from each other in nature, or
 remote in situation:—a  circumstance worthy of attention, as
 putting an end to the verbal disputes respecting the continu-
 ation of membranes, and affording  an explanation of many
 morbid phenomena.
   25.  As most of the solids owe their existence to this mem-
 brane, so again its origin is derived from the  lymph of the
 blood.  I have  found the lymph  changed into this  mem-
brane, when transuded on the  surface of inflamed lungs, and
by forming false membranes, it afterwards unites these organs
to the  pleura.
  26.  We  shall now consider some varieties of this mem-
brane.  In general,  it is  more delicate, caeteris paribus,  in
man  than  in animals,—a  distinguishing  prerogative, by
which our sense  is rendered  more  delicate, and our mo-
 tions  and other functions more  perfect*    Among dif-
 ferent individuals, it varies much  in  laxity and firmness,
according to  age, sex, temperament,  mode of life, climate,
&c.
  Finally, it varies in different parts; more lax in the pal-
  * I have treated this point at large in my work, De Generis humani varie-
tate nativa, p^ 46, edit. 3. 
OF THE MUCOUS WEB.
15
pebrse and preputium, and behind the fraenum of the tongue;
less so round the ears.
  27. Besides the purposes before mentioned,  (22, 23) it is
destined for the  reception of several  kinds of fluids.  Its
chief use in this respect is to  receive  that serous  halitus
which moistens  and lubricates every  part.   This,  when
formed by the blood vessels, it imbibes  like a sponge, and
delivers over to  the lymphatics, thus constituting the grand
connection between these two systems of vessels.
  28. In certain parts its office is to contain peculiar fluids,
v. c. in the eye, existing as the  vitreous membrane, it con-
tains the vitreous humour :  in the bones,  as the medullary
membrane  (improperly  denominated  internal periosteum,)
the marrow ; in  soft parts, it is in great abundance, and con-
tains the rest of the fat, of which we shall speak hereafter.
                         NOTE.

  (A) The generally received appellation of cellular mem-
brane appears preferable to that of mucous web adopted by Blu-
menbach from Bordeu (Recherches sur le tissu Muqueux^)
and especially in this work, as our author (par. 40) suggests
the title of vis ceUulosa for the contractile power of the mem-
brane. 
16
OF THE VITAL POWERS.
                       SECT.  IV.

  OF THE VITAL POWERS IN  GENERAL, AND PARTICULARLY  OF
                       CONTRACTILITY.

  29.  Hitherto we have spoken of the solids, as the con-
stituents of the system; we now shall view them as endowed
with vitality,—-capable  of receiving the  agency of stimuli,
and of performing motions.
  30.  Although vitality* is one of  those subjects which are
more  easily known than defined, and usually indeed render-
ed  obscure rather than illustrated  by an attempt at defini-
tion, its effects are sufficiently manifest, and ascribable to pe-
culiar  powers  only.  The  epithet vital is  given to  these
powers, because on them so much depend the actions of the
body during life, and of those parts which for a  short time
after  death preserve  their  vitality, that they  are not re-
ferrible to  any qualities merely  physical, chemical, or  me-
chanical.
  31.  The latter  qualities, however, are of  great  impor-
tance  in  our   economy.   By  physical  powers,  dependent
on  the density and figure of  the  humours  of the  eye,
the rays of light  are refracted to the axis;  by mechanical,
the epiglottis is elastic; by chemical affinity, the  changes
of respiration  are effected.   But the perfect difference  of
  • A host of authors on the vital powers will be found in Fr. Hildebrandt's
Lehrbueh der Physiologie, p. 54, sq. edit. 2, 1809, to whom we may add E.
Bartel's Syttemat. Entwurf ciner Allgemeinen Biologic Francof.  1808, and J.
B. P. A. Lamarck's Philosophic Zoologiqtte, Paris, 1809,11 vols. 8vo. 
OF THE  VITAL POWERS.                 17
these dead powers from  those which we  are now about to
examine, is evident from the  slightest comparison of an or-
ganized economy with any inorganic body, in  which  these
inanimate  powers are equally strong.
   32.  Indeed the vital powers are most conspicuously mani-
fested  by  their  resistance and superiority  to  the others;
v. c. during life, they so  strongly oppose the chymical affini-
ties which induce putrefaction, that Stahl and  his followers
referred their  notion  of life to  this antiseptic property ;*
they so far exceed the force of gravity,  that, according to
the celebrated  problem  of Borelli, a dead muscle would be
broken  asunder  by  the very same weight, which, if alive, it
could easily raise, &c.
   33. As  on the one hand, the  vital  properties  are  com-
pletely  different from the properties of dead matter, so, on
the other, they  must be carefully  distinguished  from the
mental  faculties  which  will  form  the  subject  of the next
chapter :  between them, however, there exists an intimate
and  various relation  observable in many  phenomena, but
especially in  the  diversity of temperament.
   34. The vital energy  is the very basis of physiology, and
has therefore been  always  noticed, though  under different
appellations.   The  titles  of impetum faciens,  innate  heat,
archaens, vital spirit, brute life, head of the nervous system,
active  thinking principle, vital  tonic attraction, have been
bestowed upon it by different authors.
   35- Nor has there  been  less variety in the  notions and
  *"Life formally is nothing more than the preservation of the body in
mixture, corruptible indeed, but without the occurrence of corruption.*'
Stahi.
  " What we call life is opposite to putridity."  J. Juitkhb
                           D 
18                OF THE  VITAL POWERS.
 definitions  to which it  has  given rise; though in this  one
 point all have agreed,—that  its nature and causes are most
 obscure. (A.)
   36. As to the question so long agitated by physiologists,
 whether the diversity of the  phenomena exhibited in  the
 similar parts of the  living solid, are to be attributed  to mo-
 difications  only, or  to distinct species, of  the  vital energy,
 we  think it best to establish  distinct orders  of the vital
 powers, according to the variety of phenomena by which they
 are manifested.
   37- These phenomena are threefold.  Organic formation
 and increase; motion in the  parts when formed; sensation
 from the motion of certain similar parts.
   38. The  first  requisite involved in the  name and notion
 of an organized body, is a  determinate form  designed  for
 certain ends.  That species,  therefore, of the  vital powers
 is most general, which  produces  the  genital and nutritive
 fluids, and prepares them for organic nature.   This species
 we have denominated the nisus formativus,  since it is  the
 source of all generation, nutrition,  and reproduction, in each
 organized kingdom.
  39.  Those vital  powers  which are manifested (37)  by
 motion, properly so called, in parts already formed,  may be
 divided into common  and proper.   The common  are those
belonging to similar parts which  are widely  distributed ;
v. c. contractility to the mucous structure;  irritability to
 the  muscular fibre.  (B.)   The proper are those possessed
 only by individual organs, whose!" motions are peculiar and
characteristic.
 40.  Contractility is as  generally  distributed  as  the mu-
cous  structure,  which  it may be  said  to animate  ; and
therefore would   perhaps  not improperly be  called the  vis
celluhsa.  It is   characterized by  a  simple  and  not very 
OF THE VITAL POWERS.
19
 sensible effort to contract and react upon its contents, espe-
 cially upon its source of moisture,—the serous vapour and to
 propel this into  the lymphatic system.*
  41. Irritability, we mean the irritability of Haller, is pecu-
 liar to the muscles, and may be  called  the vis muscularis.
 It is marked by an  oscillatory or tremulous  motion, distin-
 guished from the action of  si.nple contractility, by  being far
 more permanent, and by occurring far more easily on the ap-
 plication of any  pretty strong stimulus.f
   42. Such are the common (39)  moving vital powers.   But
 some organs  differ  from the  rest so much in their structure,
 motions  and functions, as  not  to come  under  the  laws
 of the common orders  of vital  power.  We must, conse-
 quently,  either reform the  characters  of these orders, insti-
 tute  new ones, and extend  their  limits,  or till this be done,
 separate  these peculiar motions  from the common orders,
 and  designate  them  by the name  of vitoc proprice.\   As
 examples may  be  adduced, the  motions  of  the  iris ; the
 erection of the nipple;  the motions of  the fimbria? of the
 Fallopian tubes; the action of the placenta, and of the womb
 during labour;  andjBrobably the  greater part of the function
 of secretion.^

  •That Haller and Theoph. de Bordeu, the chief writers on the mucous
tela, did not forma just conception of this vital power, will be evident from the
latter's Reeherchet sur le Tissu Muqueux, Par. 1767, 8vo. and the dissertation
of the former on Irritability in the  liictionnaire  Encyclopedique  d°Yverdun.
T. xxv.
  + Haller De Partibus Corp. Hum. irritabiabus in the Nov. Comm. Soc. Reg.
 Scient. Gotting. T. iv.
  11 have spoken of these at large both in  my treatise De Iridis Motu 1784,
and my programma De Vi  VitaU Sanguini deneganda 1795.
  § On the vita propria o; the absorbent vessels consult Seb. Justin.  Brug-
mans, De Causa Absorptionis per Vasa Lymphatica.   Ludg. Bat. 1795, 8vo 
2P                  OF THE VITAL POWERS.
  43.  So much in regard  to  the vital powers displayed  by
motion.  (37, 39, 42.)  We  have now to speak of  sensibility,
which is peculiar  to  the  nervous  medulla  communicating
with the sensorium.   It bears the title of vis nervea, and is
the cause of perception when irritation is excited in parts to
which it is  distributed.*
  44.  The  order which we have followed in enumerating  the
vital powers, (38,43,) is that in which they successively arise
both during our formation and after birth.
  The nisus formativus must take place before we can ascer-
tain the  existence of the new conception.
  Then contractility is exerted in the gelatinous substance of
the embryo.
  When the muscular fibres are produced, they acquire ir-
ritability.
   In those few organs whose motions cannot properly be re-
ferred either to contractility or irritability, there next exists
a vita propria.
   Finally,  after birth, sensibility, is superadded.
  45. Similar also is  the order, according to which the vital
powers, both common and proper, are, distributed to the  or-
ganized bodies of each kingdom.f
  On the peculiar vital properties of the arteries consult Chr. Kramp, Kritih
der Praktischen Arzneikunde.  Lips. 1795, 8 vo.
  Many  ot the phenomena now mentioned are ascribed by others to an or-
gasm, to use an old expression, struggling from the  centre to the cirumfe-
rence, and lately designated vital turgor.
  * Fouquet in the Dictionarie Encyclopedique de Paris T. xv. Art. Sensibilite.
  \ Consult C. Fr.Kielmeyer Uber die Verhhltnisse der organischen Krafte inder
Reihe der versc/iiedenen organisationen, 1793, 8vo H. F. Link Uber die Lebens-
krafte in naturhistorischer Rucksicht. Rostoch. 1795,8vo. 
OF THE  VITAL POWERS,
21
  The formative power must be most universal; without it
indeed organization cannot be conceived to exist.
  Contractility likewise is common to each kingdom.
  Irritability and sensibility, in the sense above explained, are
peculiar to animals.
  Lastly, the vita propria is variously observable in some or-
gans, particularly the generative, both of certain animals and
vegetables. (C)
  46- It is scarcely necessary to remark, that most of these
modes of vital energy, though necessarily distinguished into
orders, are intimately connected; v. c. the mucous membrane,
forming the basis and seat of contractility in so many organs,
is interwoven also with the irritable muscular fibres* and the
sensible nerves.
  47- Whatever may have been the opinions of physiolo-
gists  respecting  the  difference or  identity  of  the  vital
powers, it is universally  agreed that they exist in the simi-
lar solid parts,  as the ancients called  them, of  which the
organs or dissimilar parts  are composed.  But  it has  been
disputed, and  particularly  of  late,  whether  vitality is pe-
culiar to the solids, or common also to the fluids; and the
latter being granted, whether or no the  blood alone is  so en-
dowed.
  48- As to the first question, the whole natural history of
each organic kingdom, as far as it  has hitherto been cultivat-
ed, abundantly shows that those living parts, however deli-
cate, of all known  animals  and  vegetables,  are solid; a cir-
cumstance necessarily implied  in their determinate figure
destined  for certain  uses.   For,  not  to  speak  of entire
animals  (which, however simple,  as worms, are  neverthe-


  * See Abildgaard in the Acta Reg. Soc. Med. Havniens. T. 1. 
22
OF THE VITAL POWERS.
 less  supplied with  enveloping membranes) the newly laid
 egg,  though at  first  sight merely fluid, on a more careful
 examination is discovered to consist of different membranes,
 of the halones, the cicatricula, &c
   Humidity is indeed  necessary  in the living solid, for the
 exertion of vitality.  But that  vitality exists in the solid, as
 solid, is proved by the  well known instances of animalcules
 and the seeds of plants,  in which, although  long dried, the
 vital  principle is  so  entire, that they  again live and germi-
 nate.
   49. With respect to  the supposed exclusive vitality of the
 blood, I candidly confess  that no argument has been adduced
 in its favour since the  time of  Harvey, which might not, I
 think, be more easily, simply, and naturally explained on the
 contrary supposition.
   For example, the incorruptibility of the blood during life,
 is far more  explicable from the perpetual  changes which it
 undergoes, especially in respiration.
   That the  blood is the material from which  the living
 solids are  produced, is  no stronger an  argument of its vi-
 tality, than  the   formation   of nymphseae and   so  many
 other remarkable  plants,  would be  for the  vitality  of
 water.
   It is difficult to comprehend how the  coagulation of the
lymph of the blood can  demonstrate  its vitality.   The  or-
 ganic formation of this lymph in  generation,  nutrition, and
 reproduction,  depends   not   upon  the  lymph   itself,  as
lymph, but upon the action  of the nisus formativus (38) up-
on it.
   50. Those  who formerly  contended*  that  the  blood


 '• V. C. Dan. Bernouilli De  Respiratione,  Basii., 1721. 
OF THE VITAL POWERS.                  23
 acquires in the  lungs from the air a certain  principle to be
 universally distributed during circulation, for  the purpose of
 imparting  motion, &c. to the organs, were right,  if chey re-
 garded that  principle (analogous to the  oxygen  of the mo-
 derns) as  the stimulant of the  living  solid;  wrong, if they
 regarded it as vitality itself.
   51.  For it is on all hands  agreed, that  no motion occurs
 i>ut upon the action of stimuli, to receive  which  action the
 vital powers  are naturally adapted and intended.
   52.  These stimuli,* however multifarious, are convenient-
 ly reduced to three  classes ; chemical, mechanical, and men-
 tal.   For the present, we shall say nothing of their various
 modes of action, in some instances direct, in others indirect,
 by sympathy and  sensorial reaction.   It is sufficient at pre-
 sent to cite a few examples of functions, to which each class
 of stimuli  conspires : such is the increased secretion of tears,
 saliva, bile, &c. and  the  venereal turgescence of the geni-
 tals.
   53.  If the nature of stimuli is  infinitely various, no less
 so are  their effects,  according to their  nature, intensity,  or
 continued  and  repeated  application  to  the living  solid.
 Hence  they  are  generally divided  into exciting  and  de-
pressing.
   54.  The  power  of certain stimuli in increasing the effects
 of others,  is very remarkable : v. c.  the power  of caloric,
  " Respiration  supplies a very subtle  air, which, when intimately mixed
with the blood, greatly condensed, conveyed to the moving fibres, and al-
lowed by the animal spirits to exert its powers, inflaies, contracts *nd moves
the muscles, aid thus promotes the circulation of fluids, and imparts motion
to mobile pans "
  • Latir. Bellini De Sanguinis Mistione, p. 165—193
  Sylvest. Douglas De  Stimuhs,  Lugd. Bat. 1766. 
24                  OF THE VITAL POWERS.

upon which probably national temperament chiefly depends.*
That of joy, a  most  energetic  mental  stimulis  is similar.f
Likewise perhaps that of oxygen,  (50) by whose chemical
stimulus the vital powers,  particularly irritability, are greatly
excited  and more disposed to  react, upon the impulse of
other stimuli.
  55.  Not  less considerable than the variety of stimuli, is
that more minute discrepancy of the different organs,  and of
the same organs in  different individuals, according to age,
sex, temperament, idiosyncracy, habit, mode of life,  &c, to
which are  owing the diversified effects  of the same stimuli
upon different organs,^  and  even upon  the same  in different
individuals, and upon which depends what the  English have
lately termed specific irritability.§
  56.  Lastly, the influence of stimuli by means of sympathy,
is very extraordinary : by its  means, if one part is excited,
another, frequently very remote, consents in feeling, motion,
or some peculiar function. ||
  The   primary  and  most  extensive  cause of sympathy
  • Montesquieu De VEsprit  des Lois.  T. ii. p. 34.  London, 1757,
8vo.
  f Jo. Casp. Hirzel De Animi Icetiet erecti efficacia in Corpore sano et cegro.
Lugd. Bat. 1746.
  + Called Le Tact ou le Gout particulier de chaque Partie, by Theoph. de
Bordeu, in his Recherches Anatomiques sur les Glandes, p. 376. sq.
  § Sam.  Farr on Animal Motion, 1771, 8vo. p. 141.
  Jo. Mudge's Cure for a recent catarrhous  Cough.  Edit. 2.  1779, 8vo. p.
238.
  Gilb. Blane On Muscular Motion, 1788, 4to. p. 22.
  J. L. Gautier De irritabilitatis JVotione, &c. Hal.  1793, 8vo. p. 56.
  0 J. H. Rahn De Causis Physicis Sympathise. Exerc. 1.—vii. Tigur. from
1786, 4to.
  Sylloge selectiorum ofiusculor de mirabili sympatfda qua partes  inter, divenas
c. h. intercedit.  Edited by J. C. Tr. Schlegel. Lips. 1787, 8vo. 
OF THE VITAL POWERS.
25
 must be referred to the nerves,*  and  indeed  chiefly to the
 sensorial reaction ,-f so that if one nervous portion is excited,
 the sensorium  is  affected, which reacting  by  means  of the
 nerves on  another part, draws it into consent with the first,
 although there  exist  between them no immediate nervous
 connection.   Such  is  the   sympathy  of  the  iris,  when
 the retina  is stimulated  by light;  and  of the diaphragm
 during sneezing,  when  the Schneiderian  membrane is  ir-
 ritated.
   There  are other  examples  of sympathy, in  which  the
 nerves, if they have any, have a more remote  and accessory
 share \\  among  these must be  placed the  sympathy  along
 the  blood  vessels, strikingly instanced between the   inter-
 nal  mammary  and  epigastric  arteries,  especially in  ad-
 vanced pregnancy:  that  along the  lymphatic vessels,^ also
 most  remarkable  during  pregnancy  and  suckling;  and
again, that dependent on analogy of structure and function,
v. c. the  sympathy of the lungs  with  the surface and  intes-
tines. (E)
  • G. Egger (the author Lawr. Gasser) De consensu nevorum. Vindob. 1766,
8vo.

  ■j- J. G. Zinn's Observations on the different Structure of the Human Eye
and that of Brutes.  Diss. ii. 1757. in the Comment Soc. Reg.  Sdent. Gotting.
antiquiores. T. 1.

  X Consider the constant sympathy of heat between certain parts of some
animals, v. c. of the hairs with  the fauces,  in variegated  rabbits,  sheep,
dogs, &c. of the feathers with the covering of the bill and feet in varieties of
the domestic duck.    That many such instances  are not referable to the
influence of nerves, I contended in my Comm.  de Motu iridis, p. 12, et seq.
and also in my work de Generis humani varietate nativa, p. 364. et seq.

  § Innumerable pathological phenomena will be  found explained by this
sympathy in S. Th.  Soemmerring's De Morbis Vasorum Absorbentium  Diss.
qua premium retulit.  Francof.  1795. 8vo.
                          E 
26
OF THE  VITAL POWERS.
  57. The vital  powers  will  be hereafter  separately  con-
sidered, under the distinct heads of our subject.  The nisus
formativus  under  the  head  of  Generation;  irritability
under that of the Muscles; sensibility under that of  the
nervous System /  the  vita  propria  when  occasion  re-
quires.
  58. Besides our former brief remarks (40)  upon contrac-
tility, a few  more minute will  at  present  be very  oppor-
tune.
  It prevails universally, (40)  wherever the mucous  tela is
discoverable.
  It is  consequently  most  abundant in parts destitute  of
proper parenchyma, but  composed almost entirely of mucous
tela, v. c.  in certain  membranes : for no one  will deny their
contractility, who reflects  upon  the spastic motions  of the
dartos, the male  urethra, or the gall bladder, which  during
d<;ath is  always  closely contracted  upon any calculi it may
contain.
  It appears  also in  those viscera  which consist chiefly of
this  tela,  v. c. in the  lungs,  whose external  surface we have-
found on  living dissection very contractile ;  but by no  means,
as Varnierus asserts, truly irritable. (F)
  The presence of contractility even  in the bones, is demon-
strated by the  shrinking of the alveoli after  the loss of the
teeth, and by the process of necrosis, by which the new bone,
when tt}e  dead portion is extricated from its cavity, contracts
to its natural size and figure. (G)
  The vitreous substance of the teeth being destitute  of this
tela (22)  possesses no contractility, as  I think appears from
the circumstance of  its not shrinking,  like  the alveoli, if  a
portion is separated by caries or fracture.
  59. This  contractility of the mucous  tela is  the  chief
cause of  strength, health, and  beauty;  since  on  it depend 
                   OF THE VITAL POWERS.                 27

the vital elasticity and fulness,* and indeed the tone of parts,
so elegantly described  by Stahl; for by its  a eaus, the mu-
cous tela, to mention one only of its functions, absorbs, du-
ring health, the serous fluid  (27) like a sponge, and propels
it  into  the lymphatic vessels :  in disease, on the  contrary,
having lost its tone, it is filled with water, giving rise to oede-
ma and similar cachexies.
   60- Finally, the great influence of this contractility in pro-
ducing the peculiar constitution and  temperament? of indi-
viduals, is manifest from its  universal  presence, its  close
union  with  the other  vital powers, and from its  infinite
modes dna degrees in different persons.
                          NOTES.

   $*?'} ( See Note to Sect. VI.
   (D.))
   (E.) Mr. Hunter divides sympathy into general and par-
tial ; such  as  fever from a wound, and  convulsion of the
diaphragm  from  irritation  in  the nose.  Partial sympathy
he  subdivides into  remote,  contiguous and continuous,—
Where there is  no evident connexion between the sympa-
thising parts, sufficient to  account  for  the circumstance,—
where  there  is proximity of the sympathising  parts,—and
where, as most commonly, the  sympathising parts  are conti-
nuous .f
  * Hence after death, even in young ubjects full of juices, the back, loins,
and buttocks, having for some time lost their vital tone, are, if the body is
supine, depressed and flattened by the superincumbent weight, which now
is  not resisted: this appearance I regard among the  indubitable signs of
death.
  f Treatise on the Blood, &c. Introduction. 
.28
OF THE VITAL POWERS.
  Bichat's division  is much  better.*  It cannot be  under-
Stood,  indeed, till after the perusal of the  note  to the sixth
section.  He considers  sympathy as affecting  either animal
sensibility  or contractility, or  organic  sensibility or  con-
tractility.   Sympathy does  not arise  from  nervous com-
munication, because it frequently happens that  no particular
nervous  communications of sympathising parts are discover-
able, while  remarkable ones  exist  between other parts not
disposed to sympathise.!   Sympathy of animal contractility
occurs only when the nerves, connecting the affected muscles
with the brain, are entire; when they  were divided  by  Bi-
chat, the convulsions in  the corresponding muscles  ceased.
The sympathies of the organic  functions are never ascriba-
ble,  as many might  imagine, to  continuity of  surface;  for
after dividing the oesophagus of a dog,  Bichat produced vo-
miting equally as before, on irritating the fauces.
   (F) Our author here, as in paragraph 135, means the pul-
monary portion of the pleura, and very properly regards this
and other  serous  membranes,  as condensed  cellular  sub-
stance ; that is, as a substance not originally cellular and now
condensed, but of  the same nature  with  the cellular mem-
brane, though much more  compact.  Consult Bichat's Traite
des Membranes.
   (G) See note to sect. 6.
* Anatomie Generale. T. i. p. 183, sq,
f Consult Whytt's Observations on Nervous Diseases. Ch. i. 
OF THE MENTAL FACULTIES.               ;29
                        SECT. V.

                 OF THE MENTAL FACULTIES.

   61.  JMan, whom we have found  possessed of  a body,
answering completely  both in matter  and texture,  as well
as vital powers, the purposes  of its formation, is endowed
likewise with  a mind,  a  " divinae  particula  aurae,"  inti-
mately connected with  the body,  and developing  by  edu-
cation  and exercise various  kinds of faculties, which we
shall  concisely enumerate, as  far as they  belong to our
subject.*
   62.  The sensibility of the nerves, mentioned  above among
the vital powers, (43) constitutes, as it  were, the  medium
which  propagates the  impressions  of stimuli upon  sensible
parts, and especially upon  the organs of sense (to be hereaf-
ter examined,) to the sensorial portion of the brain, in such
a manner that they are perceived by the mind.
  63.  The mental faculty to be first  enumerated,  and in-
deed to be placed at the bottom of the scale, is the faculty
of perception, by means  of which the  mind  takes cogni-
zance  of  impressions made  upon the  body,  and  chiefly
upon  the  organs of sense,  and  becomes  furnished  with
ideas.
  * Consult Alex. Chrichton's Inquiry into the nature and  origin of mental
derangement, comprehending a concise system of the Physiology and Pathology
of the human mind.  Lond. 1798, 2 vols. 8vo.   Imm. Kaut's Authrofiologie in
pragmatischer Hinsicht.  Kbnisb. 1798, 8vo. Chr. Meiner's Untersuchungen
Uber die Denkkr'dfte  und Wdlenskr'dfte des Menschen nach Anleitung der Er-
fahrung.  Gott 1806, 2 vols. 8vo. 
30
OF THE MENTAL FACULTIES.
   64. This faculty is assisted by  another of a higher order.
—attention, which so  directs the  mind when excited to any
idea, that  it dwells upon that idea alone,  and surveys  it
fully.
   65. To preserve and recall the marks of ideas, is the of-
fice of memory, that part of the mind, which, in the language
of Cicero,  is the  guardian of the  rest-
   66. Imagination* on  the  contrary, is that faculty of the
mind, which represents not merely the  signs,  but the  very
images of  objects in the most lively manner, as if they  were
present before the eyes.
   67. Abstraction forms general notions more remote*  from
sense.
   68. Judgment compares and examines the relations of the
ideas of sense and of abstract notions.
  69. Lastly reason,—the most noble and excellent of all the
faculties, draws inferences from the comparisons of the judg-
ment^
  70. The combination  of  these   cnostitutes  the  intellec-
   * The difference, analogy, and relation of memory and judgment, have
 given rise to various controversies.  Some celebrated psychologists have in-
 cluded both under the word  iTnagtnation taken in its most comprehensive
 sense,  and  have divided it  into two species; memory, representing for-
 mer ideas, and the facultas fingendi,  representing such  ideas only  as  are
 formed by abstraction.  They again divide memory into sensitive (imagina-
 tion in a stricter sense) and intellectual.
   Their facultas fingendi, they also subdivide into intellectual (the more ex-
 cellent,) and phuntasy, obeying  mechanical laws.  Feder's Grundsiitze agr
• Logik und Metaphysik.  Gotting. 1794. p. 20.
   f Of ihis the highest  prerogative  of the human mind, by which man
 exerts his dominion over other animals, and indeed over the whole creation,
 I have fully treated in my book De Gen. Hum. Var. Nat- p. 32, ed. 3. 
                OF THE MENTAL FACULTIES.               31

tual faculty ; but there is another order, relating to appetency,
to take the word in its most extensive meaning.
  7.1. For since we are impelled by various internal stimuli
to provide food and other necessaries, and also to satisfy the
sexual instinct, and are impelled the  more violently, in pro-
portion as imagination inflames our wishes, desires, properly
so called, are thus produced; and  if,  on the other hand, the
mind becomes  weary of  unpleasant  sensations,  aversions
occur.
  72.  Finally, that faculty which selects out of many desires
and aversions, and can at pleasure  determine  to perform
functions for certain purposes, is denominated volition.
  73. Our order of enumeration corresponds with that of the
developement of the faculties, and with the relation in which
those termed brute,—common to man  and animals, and those
more or less peculiar to man, stand to each other.
                         NOTE.

  The great peculiarities of Gall's Metaphysics are, that the
faculties usually regarded as distinct, are  considered com-
mon ; and certain  faculties  established which  were not re-
garded as distinct.   Spurzheim enumerates thirty-three dis-
tinct faculties, and  the various modes of operation common
to all these, constitute judgment, memory, &c.—the distinct
faculties of former metaphysicians. 
32            OF HEA1TH AND HUMAN NATURE.
                      SECT. VI.

              OF HEALTH AND HUMAN NATURE.


   74. Since health,* which  is  the  object of physiology,
depends upon such  a  harmony  and  equilibrium  of  the
matter  and  powers of the system, as is requisite  for the
due  performance of  its functions, it  is  very  evident  how
the four principles examined above,  contribute to  its sup-
port.
   75. Fluids properly prepared  are the first requisite; in the
next place, solids duly formed from the fluids; then the in-
vigorating  influence of the vital powers ; lastly, a sound mind
in this sound body.
   76. These  four principles  act and react perpetually upon
each other: the fluids are stimuli to the solids ; these again
are calculated by their vital powers to experience  the  influ-
ence of these stimuli, and react upon  them.   In  reference
to the intimate union of  the mind with  the  body,  suffice
it at present to  remark,  that it is far more  extensive  than
might at first  be  imagined.  For  instance, the influence of
the will is not contained in the  narrow limits of those ac-
tions designated voluntary in the schools of physiology; and
the mind,  on the other hand, is influenced  by  the affecr
  • Theod. G. Aug. Roose Uber die Krankheiten der Gesunden, Gottlnr,
1801, 8vo.
  G. Chr. Klett, Tentamen evolvendi notionem de sanitate hominis, Wirceb.
1794, Svo-. 
               OF  HEALTH AND HUMAN  NATURE.               33

 tions of the body, in many other ways than by the perceptions
 of sense.*
   77.  From the endless variety and modification of the con-
 ditions belonging to these  four principles, it  may be easily
 understood,  what great latitude] must be given to the notion
 of health.  For  since,  as  Celsus long ago observed,  every
 one  has some part  weaker  than the rest, Galen  may in this
 sense assert with truth, that  no one enjoys perfect  health.
 And even  among  those whom we  commonly regard  as in
 good health, this  is variously  modified in each  individual.:{:
   78.  Upon this endless modification is founded the differ-
ence§  of  temperaments;  or,  in other words,  of the  mode
and  aptitude  of  the living  solidll  in   each  individual,  to
  * Galen, quod animi mores coiporis tcmperaluras sequantur.
  St. J Van Geuns, De corporum habitudine animus hujusque virium indice ac
moderatrice.  Harderv. 1789. 4to.

  f Galen, De, sanitate tuenda, L. 1.              >     .

  t W. F. Ad. Gerresheim, De sanitate  cuivis hominipropria.   Ludg. Bat,
1764, 4to.

  § Lavater's Physiognomische Fragmente. T. iv. p. S43.
  W. Ant. Ficker's Comment, de temperamentis  hominum quatenus exfiibriea
et structura corporis pendent Gott 1791, 4to.          ^
  J. N. Halle" m the Mem. de la Soc. M6dicale d'Emulator, iii. p. 342.

  H To the numerous arguments by which the moderns have overthrown the
doctrine of the ancients,  and proved that the temperament depends on the
living- solids, rather than on the nature of the blood, 1 may add the celebrated
example of the Hungarian sister twins, who, at the beginning of the last cen-
tury, were born united at the lower part of the back, and attained their twen-
ty-second year in this state.  They were, as is well known, of very different
temperaments; although  dissection discovered, that their sanguiferous sys-
tems anastomosed so considerably, that the blood of both must have been the
same.
                                  F 
34
01 HEALTH  AND HUMAN NATURE.
 be affected by  stimuli, especially the mental; and again,
 of the mental  stimuli,  to  be excited with  greater or less
 facility.
   79.  So  various  are the differences of degree and  com-
 bination  in the  temperaments, that their divisions and  or-
 ders may be multiplied almost without end.   We shall con-
 tent ourselves with the four  orders  commonly  received.*
 The sanguineous—excited most  readily, but slightly ;  The
 choleric —excited readily and  violently: The melancholic—
 excited slowly, but more permanently : And the phlegmatic—
 excited with difficulty.
   This division, although built by Galen upon  an absurd
 foundation  borrowed  from an imaginary depravation of the
 elements of the  blood, appears, if made to stand alone, both
 natural and intelligible.
   80.  The predisposing and occasional causes of the diversi-
 ty of temperaments are very numerous; v. c. hereditary ten-
dency, habit of body, climate, diet, religion, mode of life, and
luxury.f
   81.  Besides the  variety of temperaments, circumstances
 peculiar to every individual, by  influencing  the number, as
well as the energy and vigour of the functions, increase the
latitude (77) in which  the  term health  must  be received.
 In regard to age, the health of a new-born infant is different
 from that of an  adult;   in regard to sex, it differs in a mar-
 riageable virgin and an old  woman past child-bearing, and
 during menstruation and suckling ; in regard to mode of life,
it is different in  the barbarous tribes of North America, and
in effeminate Sybarites.
* Kant, 1. c. p. 257, sq.
t Feder in the Untersuchung uber den menschlichen Willen.  T. ii. p. 49. 
OF HEALTH  AND HUMAN  NATURE.
   Moreover, in every person, custom  has  an  extraordinary
 influence* over certain functions, v. c. sleep, diet; and  has
 therefore  acquired the name of second nature.
   82.  The  more  functions  flourish  simultaneously  in  the
.body,  the  more  considerable is its  life, and  vice  versa.
 Hence life  is greatest, when the functions have attained
 their  highest perfection in  adult age ;  and  least, when the
 functions, although  very perfect, are fewer  and  more slug-
 gish,  v. C.  in the  newly conceived embryo; life  is for the
 same reason less vigorous during sleep  than during  the oppo-
 site state.
   83. The  functions  have  been  long  divided by  physiolo-
 gists into four  classes.  This  division, although not  unex-
 ceptionable,  nor  exactly conformable  to  nature,! may assist
 the memory.!
   1.  The  first class comprehends the vital functions, so term-
 ed, because their  uninterrupted  and  complete performance
 is necessary to life.   Such are the circulation and respira-
 tion.
   2.  The  second  comprehends  the   animal  functions,  by
which animals are  chiefly  distinguished  from  vegetables.
   * Galen De Consueludine.
   G E. Stahl.  De consuetudinis efficacia generali in actibus vitalibus. Hal.
1700, 4to.
   H. Cullen, De Consuetudine. Rdinb. 1780, 8vo.
   C. Natorp, De vi consuetudinis. Gott. 1808, 4to.
   ! See Planner's Qu<est. fthysio/. p. 31.  Versuch einer Anthropologic T i.
p. 100, 222, and my own remarks on the  bad foundation of this division, in
the preface to my Enchiridion Anat. Comparatte, p. xi. sq.
   $ J. J. B rnhard's Versuch einer Vertheidigung der alien Eintlteilung dei
Functionen. ttnd einer Classification des  organisirlen KOrper, nach densefben,
Erf. 1804, 8vo. 
6             OF  HEALTH AND HUMAN NATURE.

Such is the connection of the mind with the body, especially
sense and muscular motion.
  3. The third is  the natural, by means of which the body is
nourished.
  4. The fourth, the genital, intended for the  propagation of
the species.
  We shall  now  examine  each of these separately,  begin-
ning with the vital. (A)
                         NOTES.

  (A)  The  consideration of a division as ancient  as Aris-
totle, and much preferable to that which Blumenbach adopts,
will  perhaps  form a useful  note to the  eighty-third  para-
graph and the greater part of the fourth section.
  In this, the functions are  arranged  in two classes ;  the
animal  constituting one peculiar to animals;  and the vital
and  natural  united' into another, common to vegetables  and
animals under the title of organic or vital.  The generative
relating in their object to the species rather thqp to the indi-
vidual,  and of but temporary duration, may be  thrown into a
separate and inferior division.
   We  owe  the revival of this classification, and our know-
ledge of the characteristics  of each  class of functions, to Dr.
Philip Wilson* and Xavier Bichat,! although the latter, from
  * Treatise on Febrile diseases. Ch. iii. Sect. 3. First Edition, 1799 Paper
read to the Royal Med- Society of Edinburgh, 1791, or 1792, and inserted in its
Records.   Essay on  Opium, 179d.—-Edinburgh Med. and Surgical Journal,
July, 1809, p. oOl, sq.
  ! Recherches Physiologiques sur la Vie et la Mori. 
OF HEALTH  AND HUMAN NATURE.             37
 having published  a  w«-rk expressly  on the subject, has re-
 ceived the whole honour, both in Great Britain  and on the
 Continent.*
   The animal functions render us feeling, thinking and wil-
 ling beings ;  they are the actions of the senses which receive
 impressions, of the brain which perceives them, reflects upon
 them, and wills, of the voluntary muscles which execute the
 will in regard to motion, and of the  nerves which  are  the
 agents of transmission.    The  brain  is  their  central organ.
 The vital or organic functions are independent of mind, and
 give us simply the idea of life :  they are digestion, circula-
 tion,  respiration,  exalation,  absorption,  secretion, nutrition,
 calorification.  Their heart is their central organ./
   The  organs of the animal functions are double and corre-
 spondent,  there being on each side of the median line of the
body, either two  distinct  organs, as the  eyes, ears, extremi-
 ties ,  or two correspondent halves, as  is  the  case  with the
brain, spinal marrow, nose, tongue-, &c.
   The organs of the vital or organic  functions, are  in very
few instances  double, or  situated with  their centres in the
median line and  possessed of symmetrical halves;  witness
the heart,  stomach, liver.   There are  indeed two kidneys,
but they continually differ in size, figure, and situation :  the
two lungs are very dissimilar.
   Hence  Bichat  infers,  that in  the  animal  functions  a
harmony  of action in  each organ,  or  each half  of  the
 organ,  is indispensable to perfection, when both organs  or
sides act together;  and  that   if  such  harmony  do  not
* Bichat's Antomie Generale, Tom. 1, cii. et. ciii. 
38            OF HEALTH AND HUMAN NATURE.

occur, it would be  better, were one organ  or  one half to
act alone.   This is unquestionably  true  of the  eye,  but
can be supposed by  analogy  only  with regard  to the brain,
ears,  &c.   It certainly  does not hold  good in the  action
of the voluntary muscles, or in the operations  of the brain
or spinal marrow  in willing their actions.  From the du-
plicity of the  organs, it  also happens  that one side may
cease to act  without  detriment to  the  function of the
other, while in  the vital  or organic  class  no  harmony of
action is possible,  and  the  derangement  of any  one  part
of an organ generally affects the whole;  an obstruction in
the  colon disturbs the  functions of  the  whole alimentary
canal.
   The  animal functions  experience periodical  intermissions
.—sleep. The organic or vital  continue incessantly, suffering
merely  remissions.   The blood constantly circulates, the per-
spiratory fluid is  constantly secreted, the stomach has no
sooner digested one  meal than  we commit another  to it:  yet
we shall hereafter see that the actions of the heart, lungs, &c.
have daily intervals of relaxation.
   The animal functions are much  influenced by habit;  the
vital or  organic are considered by Bichat as removed from
its influence..   The  effects of  habit  on  our  sensations
and voluntary motions are manifest :  yet I  think them
equally  great upon  the organic functions.  The  operation
of food and all descriptions of ingesta  is most remarkably
modified by habit; through it poisons become comparatively
innoxious,  and divers  bear a long suspension of respira-
tion.
   Bichat regards the  passions as  directly  influencing  the
organic  functions   only,  and  springing from  the state of
the  organs of that  class.   Here  he  is to me  perfectly  un- 
              OF  HEALTH AND HUMAN NATURE.            39

  ntelligible.  Vexation indeed disturbs the stomach,  and fear
 augments the quantity of urine ; but does not vexation equally
 and as directly  disturb the mind ? Are not, in fact, the pas-
 sions a part of the mind ?—a part of the animal functions ?
 They powerfully affect, it is true, the organic or vital func-
 tions, but this shows the close connection merely between the
 two classes of functions.
   This  connection is  conspicuous  in  respiration,  the me-
 chanical  part  of which belongs  to the  animal functions,
 the  other to the  organic;  and in the  alimentary  actions, in
 which  the food  is swallowed and the  faeces rejected by
 volition,  and the  digestion, &c. performed independently of
 our  influence, by the powers of simple life.  So close in-
 deed is this  connection,  that every  organ of  the animal
 class is the seat  of  organic functions :  in  the voluntary
 muscles, the  organs of sense, and  even  in  the brain, cir-
 culation, secretion, and absorption  are constantly  carried
 on.   This  connection is  likewise apparent in the property
 of  sensibility.    The vital  or  organic  properties  of  the
 machine  are fundamentally  sensibility and  contractility.
 In the  language  of Bichat there are animal sensibility and
 contractility, and  organic  sensibility  and  contractility,  be-
 sides the  common extensibility of matter, which he terms
 extensibilite de tissu, and  common contractility upon  the
 removal of distention,—Contractilite par defaut  d?extension,
 confounded  by  Blumenbach (58.  clause  5  and 6)  with
 purely  vital contractility,  and indeed  greater  during  life
than  afterwards.*  Animal  sensibility  is  accompanied by
• The following is Bichat's table of the properties of the living body. 
40
OF HEALTH  AND HUMAN NATURE.
 a perception  in  the mind, as  in seeing,  hearing, tasting,
 smelling  feeling :  animal  contractilicy  is  excited by  the
 volition  of  the  mind  conveyed  to  the  voluntary  muscles
 by means of the  nerves.   Organic  sensibility  is  attended
 with no perception,  and  is'  followed by  contraction totally
 independent  of  the will ;  the  heart  feels, if we  may  so
 speak, for  physiology has no  proper term  for the  idea,  the
 stimulus of  the  blood, and,  without  our  influence,  forth-
 with contracts;  the lacteals feel the  stimulus of  the  chyle
 without our  knowledge, and  propel  it  without  our assist-
ance.    But  although   we  never acquire  the least  direct
voluntary  power  over  the  actions of  organic  contractility.
"" Classet.	Genera. Species. f 1 " 1 j Animal Sensibility J 2 L Organic		Varieties.
			
1			
J Vital	r .i		
	2 J Animal .. Contractility j 2 t Organic		1
		f Sensible. Such as the motion	
			of the heart and alimen-
	1 ,.	1 i	tary canal.
.. Structural *	Extensibility		2
	2	j Insensible. Such as the mo-	
\	„ Contractility	I	tion of the capillaries.
  Although these are the general properties of the living frame, yet each
part has besides some pecularity, altogether inexplicable, not in the least,
I think, to be accounted for on Bichat's supposition of each part possess-
ing a certain degree  of organic sensibility in relation to its fluids.  What
causes the vessels of muscle to produce muscle;  of bone, bone ; of mem-
brane, membrane; what causes the secreting vessels of the liver to  form
bile, and of the testes semen, we know  not. These circumstances may be
called by Blumenbach, after Bordeau, vita: propria ; but it must be carefully
remembered that this expression simply denotes a fact, and  affords na
explanation. 
              OF HEALTH AND  HUMAN  NATURE.            41

—over the peristaltic motion  of the  intestines, or the con-
tractions of the blood vessels,  yet every organ of the or-
ganic functions  may  have  its  organic  sensibility height-
ened  into animal sensibility,  as inflammation,  for  instance
of the pleura and the joints, daily  demonstrates ; indeed,
in some organs of that class of functions, we invariably have
sensation; the stomach is the seat of hunger; in the lungs
we experience an uneasy sensation the  moment their air is
expelled.
  The nerves of the animal functions run to the brain or spi-
nal marrow; those of the organic chieflv to ganglia; but, as
might be expected, the two nervous  systems have abundant
communications.
  The animal functions have not only a shorter existence
than  the organic from their  necessity of alternate repose,
but they flourish for a shorter duration,—-they do not com-
mence till birth ; they decline, and in the natural course of
events, terminate earlier; the  organs of sense  and the mental
faculties  fail before the action of the heart and capillaries.
The decay of the animal  functions  must, in truth  be the
consequence of the decay of  the  organic, because there are
fundamentally in every part organic  functions,—circulation,
nutrition, &c  and  the perfect performance of  these in the
organs of the animal functions is indispensable to the perfect
performance of the animal functions.  Hence the impairment
of these  organic functions, even to  a small extent, will de-
range or  diminish the animal  functions, which thus will de-
cline while the organic functions are still in sufficient strength
for the parts to remain alive.
  We thus find  in every living system a class of  functions,
not in themselves dependent  upon mind, as perfect in the
                             G 
42            OF HEALTH AND HUMAN NATURE.

vegetable  as in  the animal,  and pervading every part  of
the system.  In  animals there  further  exist certain  parts
which when endowed with the common life of other  parts,
—with the organic  properties, are able  to perform peculiar
functions to  which we  give the appellation of mind :  the
organ of these functions is termed  brain, and  by means of
nerves and  medullary prolongations, it  maintains a corres-
pondence with the whole machine, influenced by and influenc-
ing the  most distant parts.   The phenomena of the mind
have  been metaphysically considered  in the  fifth  section;
they will be examined as functions of the nervous system in
the twelfth.
  The organic  functions  constitute  life in  the  proper
acceptation  of the  word*   The word  life  should be  re-
garded, like the  word attraction or  repulsion,  as merely an
expression  of a fact.   In this point of view it  may  be as
easily defined as any  other expression.  By life  we gene-
rally mean  the  circumstance of organized matter preserv-
ing its particles  in such chemical  relations as  to prevent
other  chemical   relations from inducing  disorganization,
or  even  increasing or  decreasing,  by  internal  appropria-
tion and  separation ; greatly  inclining to preserve a tem-
perature  distinct  from  that  of  the surrounding medium;
moving certain parts of itself sensibly (as  muscles)  or  in-
sensibly (as the capillaries)  independently of mere impulse,
attraction,  or repulsion, or able (as  seeds)  to  do these
things under favourable  circumstances: or  if not  orga-
nized (as the fluid which becomes the embryo, the blood,)
the  circumstance  of matter  produced  by an  organized
body endowed with  the properties above  mentioned,  re-
sisting the  ordinary  chemical influences, and  being capa-
ble of directly becoming (as the female genital  fluid) an or- 
OF HEALTH AND HUMAN NATURE.              43
ganized system so  endowed, or of directly contributing ("as
the blood) to the organized substance of an already formed
system so endowed.
  That  fluids are  as susceptible of life as solids  I cannot
doubt.   There is no reason why they should not be so, al-
though a person  who has  not  thought  upon the  subject
may  be  as  unable  to  conceive the  circumstance as a  West
Indian to conceive  that water  may by cold .become  solid.
It is impossible to deny that at  least the fluid which becomes
the embryo, possesses life, because it becomes an organized
being : although  some may perhaps contend that the male
semen acts  simply  the part of a  peculiar stimulus to  the
living fluid of the ovarian  vesicle,  others that the life of the
fluid of the  ovarian vesicle is  afforded  by the male semen.
However,  Blumenbach  in  his  Commentatio de  vi  vitali
sanguinis,*  grants  both male  and  female  genital  fluids  to
be alive, notwithstanding that  he   fancies his victory over
the defenders of  the blood's life so complete, that like that
of the  unfortunate  Carthaginian Dido, "  in ventos vita re-
cessit."   It  is  as  easy to  conceive the blood  to be alive as
the ovarian  fluid.    The great  asserter of  the life of the
blood  is  Mr.  Hunter,f  and the  mere  adoption of  the
  * In universum sane post omnia quae super hoc argumento  sive me*
ditando sive  experiundo  hactenus  elicere licuit, nulli humorum  nostri
corporis genuina vis vitalis tribtienda videtur, si uuice a genitali utriusqiie
sexus latice discesseris, utpote cui jam arte quam uterino c:ivo exceptus et.
intime mixtus in foetus formationem abit, vitales inhaerere vires formativas,
practer alia  paterni vuitus in nepotes propagata similitudo, aliaque id genus
phenomena haud inntianda demonstrare  videnlur.   Comment. Soc.  Reg.
Societ. Gotting. vol. ix. p. 12.
  f The  doctrine of the life  of the blood was maintained by  Harvey
(Exercit.  L. De generations  ordine,  &c)  Glisson (.De  ventriculo et
intestinis)   and  Albinus  (Blumenbach's Commentat.  1. c.)  I  am  sur- 
44              OF  HEALTH AM) HUMAN NATURE.
opinion  by  Mr.  Hunter  would  entitle  it to  the utmost
respect from me who find the most  ardent and independent
love of truth,  and  the  genuine stamp of profound  genius
in every passage of its  works.  The  freedom of the  blood
from putrefaction,  while  circulating,  and  its  inability  to
coagulate  after death  from arsenic,  electricity and  light-
ning,  may,  like  its  inability  to congulate  when  mixed
with bile,  be  simply  chemical  phenomena,  independent
of  vitality.   But  its   inability to  coagulate  after  death
from anger or  a  blow on  the  stomach, which  depiive the
muscles  likewise  of their  usual stiffness; its  accelerated
coagulation  by  means  of heat;  perhaps its  diminished
coagulation  by  the admixture  of opium;  its earlier pu-
tridity when drawn from old  than from young  persons;
its  freezing,  like  eggs, frogs,  snails,  &c  more  readily
when once pre\iou ly  frozen  (which  may be supposed to
have exhausted its powers);  its  directly  becoming the
solid organized substance of our bodies, while  the  food
requires  various intermediate changes before it is capable
of  affording  nutriment;  the  organization (probably to a
great  degree  independent  of the  neighbouring  parts)  of
lymph effused from the blood ; and finally  the  formation
of the genital fluids, one at least of which mUst  be allowed
by  all to  be alive, from  the  blood  itself;  do  appear  to
me  very  strong  arguments  in favour  of the  life  of the
blood,f  I  am  inclined  with Mr. Hunter to  believe that
prised that Moses should  be adduced as authority for  this opinion.
When he says  (Leviticus, ch. xvii. 11, 14.)  "For the* life of the flesh is'
in the blood"-" For it is the life of all flesh," he can mean only that when
it is withdrawn life ceases,-that it is necessary to  the life of animals  He
says, (v. 14.) " the blood of it is fou the life thereof."
  * Consult Hunter's Treatise on the Blood, &c. p. 1, ch. 1. 
OF HEALTH AND HUMAN NATURE.
45
the chyle is alive, and that vivification commences even in the
stomach, although  I should be sorry to go the same lengths
with  Albinus, who was willing  to grant life  even  to the
excrement.   For the  excretions  must be regarded as dead
matter, useless  and foreign  to  the  system,  and they  all run
with the greatest  rapidity into decomposition.  In retention of
urine, the  surgeon always finds this fluid abominably foetid ;
the faeces become so when  not discharged in due time, and
the neglect of  washing  the surface is the source of filthiness
and disease.
   The essential nature  of  life is  an impenetrable mystery,
and  no more  a subject for philosophical inquiry than the es-
sential nature of  attraction  or  of  matter.   We have reason
to  believe that  life never originates,  but was granted  at
the  creation, and is propagated from  parent to offspring;
it is  the property  of  organized systems, producing  various
effects by  various  kinds of organization, but  not quite pecu-
liar to organized matter, because  capable of being possessed
by matter in a  fluid state.
   The animal  functions  demonstrate  mind.   This  is
seated in the brain, to which the spinal mirrow, nerves, and
voluntary  muscles are  subservient.   Mind  is the  func-
tion of  the  living brain.   As  I cannot conceive life any
more  than attraction  unless  possessed   by  matter,  so   I
 cannot conceive  mind unless possessed by a brain endowed
with life.*    I  speak  of terrestrial  or  animal   mind;
with  angelic  and divine nature  we  have  nothing  to do,
and of them  we  know nothing.   To call the human mind
a  ray  of  divinitv  appears  to me  absolute  nonsense.
 Animals are  as  fully  endowed  with mind,—with  a con-
* See note (B) to Sect. 44. 
46            OF HEALTH AND HUMAN NATURE,
sciousness  of personality, with feelings,  desire  and  will,
as  man.   Observation  shows  that  superiority  of  mind
in  the animal creation is exactly commensurate with supe-
riority of brain ;  that activity of mind  and brain is propor-
tional; and  that  as  long as  the brain is  endowed  with
life, and  remains uninjured, it, like all other organs, can
perform   its  functions,  and  mind  continues ;  but, as  in
all  other organs, when  its  life is gone, its function, mind,
is  gone; when causes of disturbance affect it, its function,
mind, is affected ; if originally  constituted  defective, its
function,  mind, is defective; if fully developed,  and  pro-
perly acted on, its function, mind,  is well performed;  ac-
cordingly as it  varies, is  the  mind  also  varied; and  the
character of the mind agrees with the character of the body,
being equally irritable, languid, or torpid, evidently because
the brain is  of the  same character as the rest of the body
to  which it belongs:  the qualities  of  the mind  are  also
hereditary,*  which  they  could not be, unless  they  de-
pended,   like  our other qualities,  upon  corporeal condi-
tions ; and  the mind  is  often  disordered upon the disap-
pearance of a bodily complaint, just as  other organs, be-
sides the brain, are  affected  under similar  circumstances;
the  retrocession  of   an   eruption  may  affect  the lungs,
causing asthma ; the bowels, causing enteritis ; or  the brain,
causing  insanity; insanity  and phthisis sometimes  alter-
  * Parentibus liberi similes sunt non vultum modo et corporis fcrmam, sed
animi indolem, et virtutes, et vitia.—Claudia gens diu Romse floruit impigra,
ferox, superba: Eadem illachrymabilem Tiberinm, tristissinmm Tyrannum
produxit:  tandem in immunem Caligulem et Claudium, et Agrippanam, ip-
sumque dpmum Nermem, post sexcentos annos desitura. Gregory's  Con-
ipcctus Medicinx Theorct- 
OF HEALTH AND  HUMAN NATURE.
47
nate with each other, just like  affections of other organs.*
The argument of the  pious  and  acute  Bishop  Butler that
the soul is immortal and independent of matter, because in
fatal diseases the mind often remains  vigorous to the last,f is
perfectly groundless, for any  function will remain vigorous
to the last  if  the  organ  which performs it is  not the seat
of the disease, nor  much connected by sympathy or  in
other modes with the organ which  is the seat of the disease.
The  stomach  often calls  regularly  for food,  and digests it
vigorously,  while  the  lungs are  all but  completely  con-
sumed by  ulceration.   As  Physiologists  we  should say,
that the mind  must  perish with the brain, as much as the
secretion  of  bile  with  the  liver;  and the  consciousness
which we have  of personality, can give us  no  reason  to
believe ourselves distinct from  earth, for this,  the fly pos-
sesses equally with the  philosopher about whose  head it
buzzes.   But although I  can discover  in the  human mind
nothing  necessarily  implying  immortality  more  than  in
the minds of  brutes,  its immortality  I firmly believe,  be-
cause declared in  Revelation,  which  reason  compels  me
to  believe.   Our  immortality,   while  the  beasts of   the
field  utterly   perish,  I   cannot  but  regard  as  the free
gift of  God,  perfectly  independent of  the   constitution
which  he  has   given   us.    Our  resurrection   is   not
only  declared in  the  sacred  scriptures,   bnt  with it the
moral government and order of the world, and  " our innate
  * That evil spirits had never more hand in causing insanity than indigestion
is clearly proved to every medical man  in Farmer's  Essay on the Demoniacs
oj the New Testament.
  t  The  -Analogy  of Religion natural and repealed to the  Constitution
and Course of Nature-  By  Joseph  Butler,  LL. D. Lord  bishop  of
Durham, p. 33. 
48
OF THE MOTION OF THE  BLOOD,
pleasing  hope, our  fond  desire,  our  longing  after  im-
mortality,  our secret  dread  and  inward  horror  of  falling
into nought,"  completely harmonize.   As  of the  essential
nature of  vitality  or  attraction,  so of the  essential  nature
of animal mind, we are quite ignorant.   It may in another
order  of  things exist  independently  of  matter,  but  we
know  it only as a function  and property of  certain  living
organized  matter—brain,  and  I  believe  with Paley,  that
when  it  revives  after  death,  the  brain  will  equally  re-
vive.*
  • The great Paley's sermon on the state after death contains the  follow-
ing conclusions from various intimations in the New Testament.  " First,
that (at the resurrection) we shall have bodies.
  2. That they will be so far different from our present bodies, as to be suit-
ed, by that difference, to  the  state and life into which  they are to enter,
agreeably to that rule which prevails throughout universal nature, that the
body of every being is suited to its state, and that when  it changes its state
it changes its body.
  3. That it is a question by which we need not be at all  disturbed whether
the bodies with which we shall arise be new bodies, or the same bodies under
a new form  ; for,
  4. No alteration will hinder us from remaining' the same, provided we
are sensible and conscious that we  are so, any more than the changes which
our visible person  undergoes  even in this life, and which from infancy to
manhood  are undoubtedly very great, hinder us from being the same, to
ourselves and in ourselves,  and to  all intents  and  purposes whatso-
ever.
  Lastly, That though from the imperfection of our faculties, we neither
are, nor without a constant  miracle upon our minds, could be made  able
to comprehend  the  nature  of our future bodies, yet we are assured that
the change  will be infinitely  beneficial; that our new bodies  will  be in-
finitely superior to  those  which  we  carry  obout  with  us  in  our pre-
sent state."  Sermons on Several Subjects, by the late Rev. W. Paley, D D
p. 96. 
OF THE MOTION OF THE BLOOD.
49
                        SECT. VII.


                ©F THE  MOTION  OF  THE BLOOD.

   84. The  blood,  to  whose  great and multifarious  im-
 portance in  the  system we have slightly  alluded, (16) is
 distributed, with  a  few exceptions, (5)  into  the m< st in-
 ternal and  extreme  recesses.  This  is  proved  by the  mi-
 nute injection of the vessels, and  by  the well  known  fact,
 of blood issuing  from  almost every part, on the  slightest
 scratch.
   85. This purple fluid  does not, like  an Euripus, ebb and
 flow in  the same  parts, as  the   ancients  imagined,   but
 flows  in a  circular  course  : so that being  propelled  from
 the  heart into the arteries, it is distributed throughout the
 body, and returns again to the heart through the veins.*
   86. We shall, therefore, say  something at present of  the
vessels  which contain  the  blood;  and  afterwards, of  the
powers by which they propel and receive it.
   87 The vessels which receive the blood  from  the heart,
and  distribute it throughout the body, are termed arteries.
These are upon the  whole  less capacious than  the veins;
 • Among warm-blood animals, the egg, especially at the fourth and fifth
day of incubation, if placed under a simple microscope, such as the Lyone-
tian, is most proper to demonstrate the circulation.
  Among frogs, the most proper is the equuleus of Lieberkiihn, described
-'n the Mev. de I'Acad. de Berlin, 1745.
                          H 
 50             OF  THE MOTION OF THE BLOOD.

but  in  adult  and  advanced  age  especially, of  a texture far
more solid and compact, very elastic and strong.
   88. The arteries consist of three coats :*
   I. The exterior, called, by Haller, tht- tunica cellulosa pro-
pria; by others, the  nervous, cartilaginous,  tendinous, &c.
It is composed of condensed cellular membrane, externally
more lax, internally more and more compact:  bloodvessels
are seen creeping upon it;f it gives  tone and elasticity to the
arteries.
   II. The middle coat consists of transverse fibres4 lunated
or falciform, and almost  of a fleshy nature : hence this has
the name of muscular coat,  and  appears to be the chief  seat
of the vital powers of the arteries.
   III.  The inner coat lining the cavity of the arteries is high-
ly polished and smooth.   This is much more distinct in the
trunks and larger branches than in the smaller vessels.
   89. Every  artery  originates  either  from the pulmonary
artery (the  vena  arteriosa of the ancients),  which proceeds
from the  anterior ventricle  of  the heart and  goes  to the
lungs ;  or from the  aorta, which proceeds from the poste-
rior ventricle  and is  distributed  throughout the  rest of the
system.  These trunks divide into branches, and these again
into twigs.
   90.  According to the commonly  received  opinion, the
 united  capacity of the branches is  greater than that of the
  * For the  various  opinions respecting the number and difference s of
the arterial coats consult among others Vine. JVlalacarne Delia Osservut. in
Chirurg Turin. T. 11. p. 103.
  |Fr. liuy&ch, Respons. ad ep. problematicam, iii. Also his Thesaur. Anat.
iv. tab. 3.
  i B. S. Albinus, Annot. Academ. L. iv. tab. 5. fig. 1. 
OF THE MOTION  OF THE  BLOOD.
51
trunk  from  which  they arise.  But I  fear  that this is too
general an assertion ;  and that the  measure  of the  diame-
ter has been improperly  confounded with that of the  area.
I mvself have never been able to  verify  it, although  my ex-
peri ncnts   have  been  frequently repeated,  and made not
on  vessels injected  with  wax, bu* on  the undisturbed ves-
sels of  recent  subjects—on  the innominata and its  two
branches—the right carotid and subclavian ;  on the brachial,
and the radial and ulnar.*
   The inconstancy  of the proportion  between the capacity
of the branches  and  trunks  is clearlv shown by the  various
size of the vessels under different circumstances, v. c. by the
relative capacity  of the inferior  thyroid arterv in the i  f-mt
aid the adult; of the epigastric artery, and also of the  uterine
vessels, in a virgin  and a woman far advanced in pregnancy ;
of the omental vessels during the repletion or vacuity of the
stomach.f
   91. The  arteries,  after innumerable  divisions  and  im-
portant anastomoses^: connecting different branches, terminate
at length in the beginning of the veins.   By  this means, the
blood is conveyed back again to the heart.    The distinction
between artery and vein at the point of union, is lost.
   In the present state of our knowledge, the umbilical ves-
  * See also J. Theod. van der Kemp, De Vita. Edinb. 1782, 8 vo. p. 51.

  f This is remarkably observable in the adult stag, by comparing the area:
of the externd carotid and its branches, d-iring the spring, before th.e horns
have attained their full growth, but are still covered-with their downy inte-
gument, (called in our language, der Bast) with such as they are after this
covering has fallen off.

  * Ant. Scarpa Sull* Aneurisma.  Pav. 1804, fol. cap. 4. 
52             OF  THE MOTION  OF THE BLOOD.
 sels are to be  regarded as the only exception to the  ter-
 mination of  arteries  in  veins.   We  shall  shew  that they
 are connected with the uterine vessels, by the intervention of
 a spongy substance, called parenchyma.
   92.  Another description  of vessels  arise universally from
the artr ri- s, and are called colourless, from not containing pure
blood, either on account of  their  minuteness  or their spe-
cific irritability,  which causes them to  reject  that  fluid.
These are the nutrient and other secretory  vessels, of  which
hereafter.
   93.  The  blood conveyed from  the heart by the arteries
is carried back by the veins.
  These are very different in function and structure from the
arteries, excepting however the  minutest  of both systems,
which  are undistinguishable.
  94.  The  veins, excepting the  pulmonary, are  upon  the
whole  more capacious than the arteries;  are more ramified ;
much more  irregular in  their course and division; in adult
age, softer and more elastic ; but still very firm and remarka-
bly expansile.
  95.  Their coats  are so  much thinner, that the blood ap-
pears  through  them.   They are likewise  less  in number,
being  solely a cellular external  (somewhat resembling  the
nervous of  the arteries) and a very polished internal, also
nearly  agreeing with that of the arteries.
  A muscular coat exists in the largest trunks only.
  96.  The interior coat forms, in most veins of  more than
a line  in diameter,  very  beautiful valves, of easy plav, re-
sembling bags, generally single, frequently double, and some-
times treble, so placed, that the fundus lies  towards the ori-
gin of the vein, the limbus towards  the heart.
  These valves are  not found  in  some parts;  not  in  the 
OF THE  MOTION OF THE BLOOD.
.11
5«>
brain, heart, lungs, secundines, nor in the s\ stem of the vena
port*.
  9JT. The  twigs, or, more properly, the radicles of the veins,
unite into branches,  and these again into six principal trunks ;
viz. into the two ca> ae, superior and inferior:  and the four
trunks of the  pulmonary  vein (the arteria venosa of  the an-
cients.)
  The vena porta? is  peculiar  in this,  that, having entered
into the liver  it ramifies like  an artery,  and its extreme twigs
pass into the  radicles of the inferior  cava, thus coalescing
into a trunk.
  98. That the blood may be properly distributed and cir-
culated through the arteries  and  veins, nature  has  provided
the heart,*  in which the  main trunks of all the blood  vessels
unite, and which is the grand agent and mover of the whole
system,—supporting the  chief of the vital functions with
a constant and truly wonderful power, from  the second  or
third week after  conception, to the last  moment  of exist-
ence.
  99. The  heart alternately  receives and propels the  blood.
Receiving it  from the body by  means of the superior and
inferior vena cava, and from  its own substance through the
common valvularf orifice of the coronary veins, it conveys
that fluid into the anterior sinus and auricle; thence into the
corresponding ventricle,  which, as  well as the  auricle, com-
  • W. Cowper's Myotomia  Reformata. (Postb.) Lond. 1724, Fol. Max.
Tab. xxxvi—xl.
  f Casp.  Fr. W >lff on the origin of the large coronary vein, in the Act.
Acau saent. '','ropol. 1777. P. i.
  Petr. Tabarrani on the same subject, in the Atli di Siena.  Vol. vi.
\ 
54             OF THE MOTION OF THE BLOOD.

municates  with both orders of its own vessels, by the open-
ings of Thebesius.*
  100.  From this  anterior, or in reference to the  heart of
some animals, right ventricle, the blood is  impelled through
the pulmonary artery into the lungs : returning f om which,
it enters the four pulmonarv veins, and proceeds into their
common sinus  and the left, >r, as it is  now more  properly
termed, the posterior auricle.-j-
  101.   It flows next  into the corresponding  ventricle;
and then passing into  the  aorta, is  distributed through  the
general  arterial  system and the  coronary  vessels of the
heart4
  102.  Having proceeded  from the extreme twigs of the
general  arterial  system into the radicles  of the veins, and
from  the coronary arteries into the coronary veins, it  finally
is poured into the two venae  cavae,  and then  again pursues
the same circular course.
  103.  The regularity of this circular and successive motion
through the cavities of the heart is secured, and any retro-
grade motion prevented, by the valves which are placed at the
principal openings :  viz. at  the openings of the auricles into
the ventricles, and of the ventricles,  mto the pulmonary arte-
ry and  aorta.
   104. Thus the ring, or  venous tendon,  which forms the
limit of the  anterior auricle and ventricle, descending into
  * Respecting these openings consult among others J. Abernethy, in the
Philos  Trans. 1798, p. 103.
  f J?mes Pemda, in the Memorie Delia Societa Italiana.  T. xi. p, 555.
  % Consult Achill. Meig's  Specimen  ii. Observationwn  Botanicarum, &c.
Basil, 1776, 4to. p. 12. sq. 
OF THE MOTION  OF THE  BLOOD.
the latter cavity,  becomes three tendinous valves.*   These
were formerly said to have three apices, and  were there-
fore called trigochline  or tricuspidal:  they  adhere  to  the
fleshy  pillars, or, in common  language, the  papillary mus-
cles.
   105. In a similar manner, the limits of the posterior auri-
cle and ventricle are defined by a ring of the same kind, con-
stituting two valves, which, from  their form,  have  obtained
the appellation of mitral.^
   106.  At  the  opening  of  the pulmonary  artery^   and
aorta§ are  found  the  triple semilunar or sigmoid  valves,!]
fleshy  and elegant, but  of  less  circumference  than  the
mitral.
   107. It is obvious how these valves must prevent the retro-
cession of the blood into the cavse.   They readily permit the
blood  to pass on, but are expanded,  like a sail, against it, by
any attempt at retrograde movement.
   108.  The  texture of  the  heart  is  peculiar: fleshy, in-
deed?  but very  dense and compact,  far different from com-
mon muscularity.**   It is composed  of fasciculi of fibres,
more  or less oblique,  here and there singularly  branching
out,  curiously  contorted and vorticose  in  thtir  direction,
  • Eustachius. Tab. viii. fig. 6.—tab. xvi. fig. 3.  Santorini- Tab. Posth.
is. fig. 1.
  f Eustachius.  Tab. xvi. fig. 6.
  I Eustachius. Tab  xvi. fig. 4.
  § Eustachius. Tab. xvi. fig.  5.  Morgagni.  Advers.  Anat. i. Tab. iv. fig.
3.  Santorini, 1. c.
  H Consult Hunter, who treats very minutely of the mechanism of these
valve." in his work On tlw Blood, &c. p.  159.
  ** Leop. M. A. Caldani,  Memorie lette neW Acad, di Padova, 1814.
p. 67. 
56
SF THE MOTION OF THE BLOOD.
 lying upon each  other in  strata, closely  interwoven between
 the cavities, and  bound by  four cartilaginous bands  to  the
 basis  of  the  ventricles,  which  are  thus   supported and
 distinguished in  their  texture  from the  fibres  of the auri-
 cles.*
   109- These fleshy fibres are supplied with very  soft nervesj;
 and an  immense  number of blood vessels, which  arise from
 the coronary  arteries, and are  so infinitely  ramified,:}: that
 Ruysch described the whole structure of the heart as com-
 posed of them.§
   110. The heart is loosely contained in the pericardium. |j
 This is  a  membraneous sac, arising from the mediastinum,
 of  the same figure as  the  heart, very  firm, and  moistened
 by an  exhalation  from the arteries of the  heart.   Its im-
 portance  is  evinced  by its  existence being, in red  blooded
 animals,  as  general as that  of the  heart; and by only
two instances being recorded of its absence in the human sub-
ject.**
  • Casp. F. Wolff, in the Act. Acad. Scientiar. Petropol. for the year 1780,
sq. especially 1781, P. i. p. 211. sq. on the cartilaginous texture of the heart,
or of the cartilagineo-osseous fibres, and their distribution  at the  basis  of
the heart.
  f Scarpa's Tabule  Neurologic^ ad Illust. Hist. Anat.  Cardiac.  Nervor.
Tab. iii. iv. v. vi.
  t Ruysch. Thesaur. Anat. iv. Tab. iii. fig. 1, 2.
  § Brandis has proposed an ingenious hypothesis to explain the use  of
so great an apparatus of coronary vessels.  Versuch uber  die Lebenskraft3
p. 84.
  H Haller. Elementa Physiol. T. i. tab. 1.
  Nicholls in the Philos. Trans. Vol. Hi. P. 1. p. 272.
  ** Littre in the Hist, de CAcademie des Sc. de Paris, 1782, p. 37. Baillie, in
the Transactions of a Society for the Improvement of Medical and Chintrgi-
cal Knoioledge. T. i. p. 91. 
*
OF THE  MOTION OF THE  BLOOD.
37
   111. By this  structure, the heart is adapted for perpetual
 and equable motions, which are an alternate  systole and dis-
 astole, or contraction and  relaxation of the auricles and ven-
 tricles in succession.
   112. Thus, as often  as  the auricles  contract to impel the.,
 blood of the venae cavae and pulmonary veins into the ven-
 tricles, these are at the same moment relaxed, to receive the
 blood:  immediately afterwards,  when  the  distended ven-
 tricles are contracting to  impel the blood into the two great
 arteries, the auricles relax,  and  receive the  fresh venous
 supply.
   113.  The systole of  the ventricles, upon which is said to
 be spent one third of  the time of the whole action of the
 heart, is performed in  such  a  way, that their external por-
 tion is drawn towards their septum, and  the apex of the
 heart towards the  base."  This at first sight seems disprov-
 ed by the circumstance of the  apex striking against the left
 nipple,  and  consequently  appearing elongated:  a  circum-
 stance, however, to  be  attributed to the double impetus of
 the blood flowing  into  the auricles  and expelled  from  the
 ventricles, by which the  heart must  be driven against that
 part of the ribs. (A)
  114.  The impulse  imparted by  the heart  to the blood, is
 communicated to the arteries,  so that every  systole of the
 heart is remarkably evident  in those arteries  which  can be
explored by the  fingers  and exceed £ of an inch in diameter,
and in those also whose pulsation can be  otherwise discover-
ed, as in the eye  and ear.   The effect upon the arteries is
called their  diastole,  and  is  correspondent and synchronous
with the systole  of the heart.
  • Consul' Ant. Portal's Memotres sur la Nature SJ la Traitement de pin-
siours Maladies.  T. ii. 1800. p. 281.
                           I 
58            OF  THE MOTION OF THF BLOOD.

   115. The quickness of the heart's pulsations during health,
varies  indefinitely; chiefly from age, but also from other con-
ditions, which at all ages form the peculiar health of an indi-
vidual ; so that we  can  lay down no rule  on this point.   I
may, however, be permitted to mention the varieties which I
have found in our climate* at different ages ;  beginning with
the new-born infant, in which, while  placidly sleeping, it is
about  140 in a minute.

       Towards the end of the  first year, about   124
       -  -  -  -   -  -   -  -   second            110
       -  -------   third and  fourth   96
       When the first teeth begin to drop out      86
       At puberty                                 80
       At manhood                                75
       About sixty                                60
   In those  more advanced,  I have  scarcely twice  found it
al'dce.
   116. The pulse is, ceteris paribus, more  frequent in wo-
men than in men, and in short than in tall  persons.   A more
constant  fact, however, is its greater slowness in cold  cli-
mates.f   Its greater frequency  after meals and coition,  du-
ring continued watchfulness, exercise, or mental excitement,
is universally known. (B)
   117. The heart rather than the arteries is to be regarded
as the source of these varieties.
   Its  action continues  in this  manner till  death, and then
  •  My observations differ but little from those made by Heberden in Eng-
land.  Med. Trans, vol. ii. p. 21, et seq.
  \  J. H. Schonheyder De Resolutione et Impotentia motus Muscularis. Hafn.
1768, p. 15.  Wi*h which work compare the observations  of F.  Gabr. Sul-
zer in the Naturgesch, des Hamsters, p. 169. 
OF THE MOTION OF THE BLOOD.
59
 all  its parts do  not, at once cease to act; but the right por-
 tion, for a short period, survives the left.*
   For since the collapsed  state of  the lungs impedes  the
 course of the blood from the  right side, and  the veins must
 be turgid with  the blood just driven into them  from the
 arteries, it cannot but happen that this blood, driving against
 the right auricle, must excite it to resistance for some  time
 after the death of the left portion of the heart.
   118.  This  congestion  on  the  right side  of the  heart,
 affords an explanation of  the  small quantity of blood found
 in the large branches of  the aorta.  Weiss,f  and after him
 Sabatier,| ascribe to  this cause likewise  the comparatively
 larger size§ of the  right  auricle  and ventricle in the  adult
 dead subject especially.
   119.  The motion  of  the  blood  is performed  by  these
 two  orders of vessels,  in  conjunction  with  the  heart.   Its
 celerity in  hearth cannot  be determined : for  it varies not
only  in different  persons, but in  different  parts  of the
same  person.    Generally,  the blood moves   more slowly
 in the  veins than in the  arteries, and in  the small  vessels
   * Slenon in the Act. Haffniens. T. ii. p. 142.
   Sometimes, though rarely, it happens that the right portion of the heart,
 oppressed with too much blood, becomes, contrary to what usually takes
 place, paralyzed before the left.  This I have more  than once observed on
 opening living mammalia, particularly rabbits.
   j-J. N.Weiss De Dextro Cordis Ventriculo post mortem Ampliori. Altorf.
 1767, 4to.
   $ Ant. Cliaum. Sabatier, In  Vivis Animalibus lentriculorum Cordis eadem
 Capacitas.  Paris, 1772, 4to.
  §Sa'Ti. Aurivilius, De Vasorum Pulmonal. & Cavitat. Cordis imequak' Am-
plitudine.  Gotting. 1750, 4to. 
60            OF THE MOTION OF THE  BLOOD.

then in the large trunks.  But these  differences  have  been
overrated by physiologists.
  The mean velocity of the blood flowing into  the  aorta,
is usually estimated at eight inches for each pulsation, or at
fifty feet in a minute.
  120.  Some have affirmed that  the  globules of  the  cruor
move more in the axis of  the  vessels,  and  with greater
rapidity, than the other constituents of the  blood.  I  know
not whether this rests on  any  satisfactory experiment, or
whether upon an improper application  of the laws  of hydrau-
lics ;  improper,  because it  is absurd  to  refer the motion of
the  blood  through  living  canals, to  the mere  mechanical
laws of water moving in a hydraulic  machine.  I have ne-
ver  observed  this  peculiarity of the globules.  My persua-
sion is still more certain  that the globules pass on with the
other constituents of the blood, and are not rotated around
their own axis,—that besides  the progressive, there is no in-
testine motion in the blood  ;  although indeed there can be
no  doubt, that the  elements of this fluid are occasionally
divided, where it is  variously  impelled  according  to  the
different  direction,  division, and anastomoses of the ves-
sels.
   121. The powers of the  sanguiferous  system are now to
be  examined ;  first, those of the heart, by far the greatest of
all; afterwards, those which  are only subsidiary, though in-
deed highly useful.
   122. That the  powers of the  heart cannot be accurately
calculated is clear, upon reflecting that neither the volume of
the blood projected  at  each pulsation, nor the  celerity nor
distance of its projection, much less the obstacles  to the
 powers of the heart, can be accurately determined.
   123.  A  rough calculation may be  made by comparing 
OF THE MOTION OF THE BLOOD.
61
every probable conjecture ;   v. c.  H  the mean  bulk  of the
blood is considered as lOpjaids,  or 120 ounces; the  pulsa-
tions 75 in a  minute, or 4500 in an  hour ;  and the quanti-
ty of blood expelled  from the  left ventricle on eachLXontrac-
tion, as two ounces;  it follows that  all  the blood must pass
through the heart 75  times every hour.  The impetus  of the
blood passing from the heart, may be conceived by the vio-
lence and altitude of  the  stream  projected from a wounded
artery,  large  and  near the  heart.   I  have seen the blood
driven to the  distance of at least five feet from the carotid of
an adult and robust man.*
   124.  This wonderful,  and,  while  life  remains,  constant,
strength of the heart, is universally allowed to depend on  its
irritability, (41) in which it very far surpasses, especially in
continuance,! (98)  every other  muscular part.$
  * The experiments of H des, in which the blood was received  into very
long glass tubes fixed to the arteries of living animals, and measured with
respect to the length of its projection, are indeed beautiful, like e^e^y thing
done by this philosopher, who was by nature calculated for such disquisi-
tions.   But if the force of the heart is to be estimated in this way, we must
take into account the pressure of  the column of blood contained in the tube
and gravitating upon the left ventricle. The result of Hales' calculations was,
that the blood being projected from the h iman  carotid seven feet and a half,
and the surface of the left ventricle being fifteen square inches, a column of
blood, weighing 51lb. 5oz. was incumbent upon the ventricle and  overcome
by its  systole.  Statical Essays, vol. ii. p. 40. London, 1733, 8vo.

 f Thus, to say nothing of the phenomena so frequently observed in the cold
blooded amphibia and fishes,  I lately found  the heart of the  dn. i :>cat for
twelve hours, in  an egg, on the fourth day of incubation.       ^  r

   $ Consult Fontana, who treats of this prerogative .if the heart rr.nutely in
his Eiwerche sopra la Fisiva ani wale, and limits it too much. Haller answered
kirn in the Literary Index of Gottingen 
62             OF  THE MOTION OF THE BLOOD.

   That the parietes of the cavities are excited to contraction
by the stimulus  of the blood, is proved by the experiment of
Haller, who lengthened at pleasure the motion of either side
of the heart, by  affording  it the  stimulus of the blood for a
longer period than the other.*
   125.  Since a supply  of nerves and  blood is  requisite  to
the action of  the  voluntary muscles, it   has  been inquired
whether these are  requisite to  the heart also.f
  The  great influence of the  nerves over the heart, is  de-
monstrated by the  size of the cardiac nerves,  and by  the
great sympathy  between  the heart and most functions, how-
ever different.   A convincing  proof of this, is the momentary
sympathy of  the  heart  during  the  most  perfect health:}:
with  the passions, and with  the prima:   vice  under various
disorders.  But the  great importance of the blood to the irri-
tability of the  heart,  is  evident by the  great abundance of
vessels in its muscular substance.
   Nevertheless it  is very probable, that the importance of the
nerves in this respect is greater in the voluntary muscles, and
of the blood in the heart.
  * Haller on the motion of the heart from stimulus, in the  Comment. Soc.
Sdent. Gottingens. Tom. i.
  G. E. llemus, Experimenta circa, circulat. sanguin. instituta. Golting, 1752,
p. 14, 4to.

  ■j- On this dispute consult R. Foster's Question, select. Physiol. Ludg. Bat,
1774, 4to.
  J. B. J. Behrend's  Dissert, qua demonstratur cor nervis carere.  Mogunt
1792, 4to. and on the other side, J. Munnik's Obsei-vationes varies, Groning.
1805,4to Lucae, 1. c. p. o7. p. ii.

  % And how much more so when the heart is diseased, is shewn in Caleb
Hill Parry's  Inquiry into the Symptoms and  Causes of the Svncope Anginosa,
rtjtnmonlii called Angina Pectoris, p. 114, Bath. 1799, 8vo. p. 111. 
OF THE MOTION OF THE BLOOD.
63
   126. Besides these powers of the heart, there  is another
which  is mechanical, dependent on structure,  greatly con-
tributing, in all probability, to sustain the circulation.   For
when  the blood  is expelled  from  the contracted  cavities,
a  vacuum  takes  place, into which, according to the com-
mon laws of derivation, the neighbouring blood must rush,
being  prevented, by means of the valves,  from  regurgita-
ting.*  (D)
  127.  We  must  now  inquire,  what  powers  are possessed
by other organs  in assisting the  circulation.   The existence
and ability of  some secondary powers  to assist, or  even in
some cases to compensate for the action of the  heart,  are
proved  by several  arguments:  v. c. the blood moves in
some parts to which the influence of the  heart cannot reach,
—in  the vena porta  and placenta;  not to mention instances
of the absence of the heart, f
   128.  The principal of these powers is the function of
the arteries,  not easy  indeed  to be clearly understood  and
demonstrated. 1. They have a muscular coat (E).  2. That
they  are  irritable, has  been proved by repeated experi-
ments.J  3. The size  of the soft nerves arising from the
  * Andr. Wilson's Liqidry into the moving po~oers employed in the Circula-
tion of the blood.  Lond. 1774, 8vo. p. 35, sq.

  | Sec. v. C. C. W. Curtius, De monstro humano  cum infante gemello, Ludg.
Bat. 1762, 4to, p. 39. W. Cooper, in the Philos.  Transac. vol. lxv. p. 316.
Haller's Opera Minora. T. iii. p. 33, C. Chr.  Klein's Descriptio Monstrorum
quorundam, Stuttg. 1793, 4to.

  fc Walter Verschuir, De arteriar. et venar.  vi irritabili ; ejusque in vasis ex-
cessu ; et inde oriunda sanguinis directione abnormi.  Groning. 1766, 4to.
  Rich. Dennison, Diss, arterias omnes et venarum partem irritabilitate prx-
ditas esse. Edinb. 1775, 8vo.
  Chr. Kramp, De vi vitaU arteiarum.  Argent. 1785, 8vo. 
64              OF THE MOTION  OF THE BLOOD.

sympathetic,  and surrounding  the larger arterial branches,
particularly in the  lower part of the abdomen,* argues the
importance of these vessels in assisting the  motion of the
blood .f
   129. The arteries pulsate, and indeed violently, so that
if, v. c. we place one  leg over  the other knee, we find not
only that it, but even a much greater weight,  may be  raised
by the pulsation of the popliteal.   Hence an  alternate systole
and  diastole,  corresponding with those  of the heart,  have
long been assigned to them.  But this, although  commonly
believed on the evidence of sense, is open to much question :\
it may be  asked, especially, whether this  pulsation  is re-
ferable to the power of the  artery,  or  only to the  impulse
given by  the  heart to the blood propelled into the aorta.
   130. And indeed after all, it appears,  that  the  diastole  of
an artery is owing to the blood,—to a lateral  distension given
by the impetus of  the blood,  so that the coats are  expand-
ed : and the vessel,  by  its elasticity, the  next  moment reac-
quires its natural thickness.   To the  same  impulse may
be ascribed the lateral motion of  the  axis,  observable  in
the larger  arteries,  if  serpentine and lying  in loose cellular
substance. (F)
  The genuine systole, produced by a  constriction  of their
  * Observe for instance, in Walter's Tabula nervor. tkorac. et abdominis,
the right hepatic, Tab. ii. O. Tab. iii. I.—the splenic, tab. ii. P. Tab. iii. m.
tab. iv. o.—The superior mesenteric, Tab. ii Q. Tab. iii. ».—the inferior me-
senteric, Tab. ii. T.—and many others.  Compare Soemmerring de c. h.
fabrica. T. iv. p. 362.
  ■j; Haller De Nervor. in arterias imperio.  Gotting. 1744, 4to. Luca  1. c.
  + Th. Kirkland's Inquiry into the present state of Medical Surgery.  London,
1783, 8vo. vol. i. p. 306, sq. 
8F THE MOTION OF THE BLOOD.
65
 usual thickness, scarcely occurs,  probably, while  the heart
 acts  with  sufficient  vigour ;  but  when  they are  unusually
 stimulated, or if the action of the heart fails or is impeded by
 severe disease, then indeed the  arteries may suppply its place
 and propel the blood by  their own vital  energy.
   131. Since Whytt* and other   illustrious  physiologists
 have been  convinced that  the influence  of the heart  could
 not reach the extreme arteries  ann the origins of the veins, they
 have ascribed the progression  of the blood in those vessels to
a kind of  oscillation, and have happily employed this to de-
 monstrate the nature of inflammation.   Many kinds of phe-
nomena, both physiological, as those  regarding animal heat,
and pathological, as those observed in  spasms, and paticular-
 ly in fevers,  favour the supposition of this oscillatory faculty,
though it is not demonstrable  to the eye.
  132.  It  remains now  to inquire  into  the  aid given to
the  returning  blood  by  the  veins, not alluding  at  all to
 their  radicles.   We  should  conclude  at first  sight  that
they  have  less active  powerf than   the rest of  the   san-
   • Physiological Essays, containing an inquiry into the causes which promote
 the circulation of the fluids in t/ie very small vessels of animals, &c. &c. Second
 Edition, Edinb. 1761,12mo.
   H. v. d. Bosch, uber  das  Muskelvermdgen der Haargefutsgen.  Monast.
1786, 8vo.

   J What is commonly, but improperly, called the venous pulsation, observa-
 ble on opening living animals and in some morbid affections, and also under
 a violent effort, does not correspond  with the action of the heart, but with
respiration; since if  an  expiration is unusually deep and lenthgened, and
the reflux of the blood  to the lungs thus impeded, the j'iglar vein swells as
far as the brain, the  subclavian as far as the basilic, and  the inferior cava as
for as the crural.
                                 K 
66
OF THE MOI'lON OF THE BLOOD.
guiferous system, and  that  the  return of their purple blood
to the heart is chiefly ascribable  to the  impetus a tergo  of
the arterial blood, and to their valvular  structure which pre-
vents any reflux.  The efficacy  of the valves in this point of
view, is  shewn  by those distensions  and  infractions of the
veins in the lower part of the abdomen, which are found desti-
tute  of valves.*
   The existence of vital powers in  the  venous  trunks, is
probable,!  from the example of the liver and placenta (127),
and from experiments instituted on living animals.   We for-
merly  mentioned the muscular  appearance  in  the  extreme
veins near the heart (95).
   133. These are the chief powers which move  the blood
and  depend upon the structure  and  vitality of the  sangui-
ferous system : we say nothing of the effect of gravity, attrac-
tion, and other powers, common to all matter.  The more re-
mote assistance derived  after birth from peculiar  functions,
v. c. respiration and muscular motion, will be manifest in our
account of those functions.
                        NOTES.

  (A) Dr. W. Hunter first accounted for this in  1746.
 '* The systole  and  diastole of  the  heart,  simply,  could
not produce  such an effect;  nor could  it have been  pro-
duced, if  it had  thrown the  blood into  a straight tube, in
the direction of the axis  of the  left ventricle, as  is  the
* G. E, Stahl, De vena porta porta malorum.  Hals. 1698,4to.
| Lister, De humoribus, p. 25. 
OF THE  MOTION OF THE BLOOD.             67/
  case with fish,  and some  other classes of animals:  but by
• throwing the  blood into  a curved  tube, viz. the aorta, that
  artery, at  its curve,  endeavours  to  throw itself  into  a
  straight line, to  increase its capacity ;  but the  aorta being
  the  fixed point against the  back,  and the heart in some de-
  gree loose and pendulous,  the influence of its own action  is
  thrown upon itself, and it is tilted  forwards against the inside
  of the chest."*
    Dr. Barclay has the following passage on this point.
    " When  the  blood is  f >rced into the  arteries, their cur-
  vatures,  near where  they issue from the  ventricles,  are
  from  their  distension  lengthened  and  extended towards
  straight lines ; and, causing the heart  to  participate in their
  motions,  compel  it to describe  the  segment  of a  circle,
  when the apex  moving atlantad and  sinistrad, is made  to
  strike  against  the left  side.   The same kind of  motion
  having also been observed  by  the  celebrated Haller,  in
  distending the left or systematic auricle, it must follow, that
  the  stroke which  is given  to  the  side,  may be the effect
  of  two  distinct  causes,  either  acting  separately,  or  in
  combination ;  but acting on a heart obliquely  situated,  as
  ours is,  in  the cavity of  the thorax, where the aspect  of
  the  base is  atlantad  and  dextrad, and  that  of the  apex
  sinistrad and sacrad.  In combination,  as the first of the
  two, by removing the pressure, will facilitate  the influx  of
  the  venous  blood into the left  or systemic auricle, which
  is situated  dorsad ; so the second, by the  influx of blood
  into the auricle, will contribute in  its  turn to facilitate the
  circular motion  of the heart, proceeding from the arteries."f
  * A Treatise on the Blood, &c. by John Hunter, p. 146. Xote.
  f The Muscular  Motions of the Human  Body, by John Barclay, M. 13
p. 567. 
68             OF THE MOTION OF THE BLOOD.

  (B) It is commonly  believed, that the pulse of every per-
son is quicker in the evening than in  the morning, and some
have supposed an increase of quickness also  at noon.  Upon
these suppositions Cullen builds his explanation  of the noon
and  evening paroxysms of hectic  fever, regarding them  as
merely  aggravations  of natural exacerbations.  The exist-
ence of the  noon paroxysms is doubtful, and the  evening one
cannot be so explained, if the writer of a paper in a late num-
ber of the Edinburgh Journal is correct.*   His observations
show the pulse to be  slower in the evening, and quicker  in
the morning.
  (C) The  heart, however, of  frogs, for instance, contracts
and relaxes  alternately, for a length of time,  when  out of the
body and destitute of blood.
  (D) The  influence of this vacuum  first pointed out by Dr.
Wilson, has been lately very ably displayed by Dr. Carson
of Liverpool.f
  The quantity of the blood,  the length of its  course, and
the  various  obstacles  opposed to  its  progress, render it
very  unlikely,  that   the   mere  propulsive power of the
heart is sufficient for  the circulation.   But great  assist-
ance must be given by the vacuum which takes  place in all
the cavities  of  the organ, when the contraction of the mus-
cular fibres  is over-   The blood  is thus drawn  into  each
relaxed  cavity, and  the  heart performs the double  office
of a  forcing and a  suction  pump.   The  rapid  but quiet
motion  of  the blood  in the  veins,  is thus accounted for,
which  would  otherwise  be inexplicable.   The  situation
  * Edinburgh Medical and Surgical Journal, 1815.
  f An Inquiry into the Causes of the Motion of the Blood, by James Carson,
M. D. 1815. 
              OF THE MOTION OF THE BLOOD.             69

of the valves of the  heart  is  also  accounted for.   There
are valves  between the  auricles and  ventricles, and at the
mouths ot the  two great arteries, because behind  each of
these four  openings is a cavity of the  heart, alternately di-
lating and affording a vacuum, into  which, without valves,
the  blood  would  be  drawn retrograde.   At the  venous
openings of  the auricles no valves  exist, because they do
not  open from  a cavity  of the  heart,—from  a part ever ex-
periencing  a  vacuum, and therefore the blood cannot, when
the auricles contract,  move  retrograde, but will necessarily
pass forwards into the ventricles, which at that moment are
affording a  vacuum.   The inferior elasticity and  muscu-
larity of the veins are  also accounted for.   If veins  were
capable  of contracting  equally  with  arteries, on  the di-
minution of  their  contents, the  suction  influence  of the
heart would constantly reduce their cavities to a smaller ca-
pacity than is  requisite for  their functions.   The  collapse
of the veins by pressure, during the suction of the  heart,  is
prevented  by  the  fresh supply  of  blood aff< rded by the
vis-a-tergo, which does exist, although it cannot be consider-
ed  as of itself adequate  to convey  the blood  back to the
right auricle.   The reason appears why a tied vein is  emp-
tied in the part nearest the heart; its  blood  is drawn  for-
wards by  suction.    We see  why  a  punctured  vein  does
not bleed,  if there  are other veins to convey the  blood dis-
charged  from  the  arteries.   The  puncture  necessarily re-
moves  the suction influence of  the heart,  and the  great
cause of the progress of the blood in the vein is taken away,
while it exists in  full force «in the other veins of the  hub.
Were it  not  tor this circumstance, a punctured vein should
afford blood  very readily.  If the  main  vein of a limb  is
wounded, the blood will flow,  because it receives  tht  whole
blood of the arteries,  transmitted  by the  vis-a-tergo,  no 
70
OF THE MOTION OF THE BLOOD.
other veins existing  into which  it can be  drawn when  the
vacuum occurs in the right auricle : what is a parallel circum-
stance, if all the veins of a limb are tied, they swell, where-
as the  ligature  of  one  causes no tumefaction in it.  These
circumstances are  no proof that the  vis-a-tergo is sufficient
of itself to bring back the blood, because  it is certain that
such a vacuum  exists, and that  such must be  the effects of
this vacuum upon  the movement of the  blood: the hemor-
rhage  in the former instance,  and the tumefaction  in  the
latter, show a certain force only in the blood, which, were
it even sufficient to bring the blood back to the heart, could
not long continue  after the assistance of suction was re-
moved.
   From the  structure  of the heart it is clear that the mere
alternate relaxation of its parietes, enlarges  its cavities and
forms a vacuum.  Experiment proves the same.   Dr. Car-
son put the hearts of some  frogs just extracted  into water
blood-warm.   They were thrown  into  violent action, and,
upon some occasions, projected  a  small  stream of a bloody
colour though  the transparent fluid.  It was supposed  that
a stream  of the  same kind continued  to be  projected  at
every succeeding  contraction;  but that,  after the first or
second,  it  ceased  to  be   observable,  in  consequence  of
the  liquid   supposed   to be  imbibed  and  projected,  lo-
sing  its bloody  tinge  and becoming  transparent,  or  of
the  same  colour  with  the  fluid  in which  the  heart  was
immersed.   The organ was  felt by the  hand  to expand du-
ring  relaxation.   He  accounts, however, for the full dila-
tation of  the  heart upon  another principle;  upon  which
it will be  impossible  to  enter into detail before the  next
 section.
   (E) Most Physiologists  grant  to the capillaries  irrifea- 
OF THE  MOTION OF THE BLOOD.
71
 bility,  tonicity,  or organic  contractility;  but some  deny
 that  arteries possess  muscular  properties.   Bichat's ob-
jections are the  absence of contraction on the  application
 of  stimuli  to them ;  the  much  greater  resistance of the
 middle coat  to  a distending force,  than that of muscular
 parts ;  and  lastly,  the difference of  the  changes  which it
and  muscles undergo,  both  spontaneously  and  by  the
 action  of  other  substances.*    Berzelius  has   multiplied
the  latter  description of proofs.f   However this  may be,
they  have  certainly vital powers  of contraction as  fully as
any parts of the body.   This  appears in  their various de-
grees of local dilatation and contraction,  under inflamma-
tion,  passions of the  mind,  &c.: and if the capillaries alone
are allowed to   possess organic  contractility, it  is  impos-
sible  to say in  which point  of the arterial track  it be-
gan.
  Dr. Parry has lately instituted  a number of experiments
upon this question.    After ascertaining exactly the circum-
ference of  arteries in  animals,  he  killed them,  and again
measured the circumference;  and after the lapse of many
hours,  when life must have been perfectly  extinguished,
he  measured the  circumference a third time.   Immediately
after  death, the circumference was  found  greatly  dimin-
ished, and on the third examination, it had increased again.
The  first contraction  arose from  the  absence of the blood
which distended the  vessel,  and  antagonized its efforts to
contraction; and  this contraction  was evidently  muscular,
or to speak more correctly, organic  contraction;  because
when vitality was gone, and this kind of contraction could no
longer take place, the  vessel  was,  on  the third examination,
always  found enlarged.
* Anatomie Generale, T. ii.   \ Animal Chemistry, p. 25, 
73
OF THE  MOTION OF THE BLOOD.
   The forced state of distenion in arteries was proved by the
 contraction, immediately occurring on  making a puncture in
 a portion of vessel  included between two ligatures.  The
 capacities of arteries  are  thus always  accommodated to the
 quantity of blood, and this circumstance gives  the arterial
 canal such properties of a  rigid tube as enable an impulse at
 the mouth of the aorta to be instantly communicated through-
 out the canal.   And this appears the great office of the con-
 tractile powers of arteries,  for,
   (F.) They do not incessantly dilate and  contract as many
 imagine.   Dr. Parry, on the most careful examination, could
 never discover the least dilatation in them, during the sys-
 tole of the ventricle, when  the pulse  is felt.   He very pro-
 perly remarks, that  the pulse is felt only when arteries  are
 more or less compressed ;  by which the motion of the blood
onwards, by the imp dse of a fresh portion from the left ven-
tricle is impeded : and this effort of the fluid against the  ob-
structing cause, gives the sensation called  the pulse.*
  * An Experimental Inquiry into the Nature, Causes, and Varieties of the
Arterial Pulse, &c. by Caleb Hillier Parry, M. D. F. R S. 1816. 
OF RESPIRATION.                    73
                         SECT. VIII.

             OF RESPIRATION AND ITS PRINCIPAL USE.


   134.   I he lungs,*  closely  connected  with  the  heart,
 both by proximity and by relation of function, are two visce-
 ra, large after birth, so light as to swim in water, and com-
 posed of a spongy, and,  as it  were, spumous, but pretty
 tenacious parenchyma.f
   135.  They  fill each  cavity of  the chest,  are  contigu-
 ous to the  sacs of  the pleurae, to which,  as  well as to the
 other contents of the thorax, they  model and apply them-
 selves. (A)
   137.  They,  in  a  manner,  hang  from  the  wind-pipe
 usually  called the aspera  arteria,  which, besides  its  inte-
 rior coat always  smeared with mucus, and   the  subjacent
 very  sensible  nervous  coat,  consists  of  another which is
 muscular, surrounding the latter, and divided, except posteri-
 orly,  by an indefinite  number of  cartilaginous  falciform
 arches.
   137. The aspera  arteria,  having entered the  thorax, is
bifurcited into the  two  bronchiae, and  these,  the  more
deeply they penetrate  into  the lobes  and  lobules  of  the
lungs, are  the more and more  ramified, losing both their
   • Soemmering und Reisseisen, Uber die Struclur, die Verrichtung und den
Gebbrauch der Lungen. Zivey Preischriften. Berol, 1808. Svo.

  j- Respecting all the organs concerned in respiration, consult Corn. J. Van
 Der Bosch's Anatomia Systematis Respirathni Inservientis Pathologica  Har-
 lem, 1801, 4to. p. 1—44.
                               L 
74
OF RESPIRATION.
cartilaginous rings aud muscular coat, until thtir extreme di-
visions terminal :r. those cells which form the chief part of the
substance of the lungs, and alternately receive and emit the air
we breathe.
   138.  The shape and magnitude* of the air cells are vari-
ous.  The former is generally polyedrical.  The latter, in
regard to surface, is scarcely to be defined :f though, indeed,
the capacity of the lungs of an udult, during a strong inspira-
tion, is about  120 cub c  inches.  The immense size to. which
the lungs may be inflated, when the chest has been  opened,
has no relation to our presenc subject.
   139.  The ells ure invested and connected by the common
but delicate mucous web,—the general vinculum of the body.
.The  texture  of each must be  carefully distinguished.   In
heali: y and very recent luny;s, I have found the cells so  un-
connected, that thev were distended in one insulated  spot by-
air cautiously inflated  into  a fine branch of the  bronchia;,
while neither the neighbouring  cells, nor the  cellular mem-
brane which lies between the cells, admitted a single portion.
If air is forcibly thrown in, the air cells are ruptured and con-
founded  with the  cellular  membrane,  and both  parts  dis-
tended.
   140. The  mucous web  surrounding  the air cells of  the
lungs is supplied  with, innumerable  blood  vessels,—divi-
sions  of the  pulmonary artery and four ^pulmonary veins,
 the branches  of  which accompany  the  ramifications  of
 the  bronchiaj4  and,   after  repeated  division,  form  at
  * Keil indulging his luxuriant iatro-mathematical genius, assigned more
than 1744,000,000 cells to each lung.

  | Lieberkii'un, with equal exaggeration, made the surface of" the cells equal
to 1500sqiv.r< <eet.
  % Eustachius. Tab. xxvii. fig. 13. 
OF RESPIRATION.
75
length a most delicate and immense  collection of reticulated
anastomoses.  This  extraordinary net-work, penetrating the
mucous web  on every side, closely surrounds  tht air cells,
so that the prodigious quantity of blood existing in the pul-
monary vessels is separated from the contact of the  air by
very fine membranes only, which Hales estimated as scarcely
Tinrff Part of an inch in thickness.
   141. As each  ramification of the  bronchiae possesses a*
peculiar bunch  or lobule of air cells, (139) so again each
of these possesses a peculiar system  of blood  vessels, the
twigs  of  which   anastomose in  the  net-work  with  one
another, but  scarcely at all with the  blood-vessels of the
other  lobules,  as is  proved  by  microscopic  observations
on  living  frogs  and  serpents,  by  minute  injections,  and
by  the phenomena of vomicae and  other  Kjcal diseases of
the lungs.
   142. The common membrane investing the  lungs is the
chief seat  of  a  remarkable  net-work of lymphatic vessels,*
which run to  numerous lymphatic  or conglobate glands,f
carefully to be distinguished from a neighbouring  order of
glands called bronchial, supplied with an excretory duct, and
of the  conglomerate kind.:):
  143.  The thorax, which contains the lungs, has an osseous
and  cartilaginous   base, somewhat  resembling  a bee-hive,
throughout very firm  and stable, but  in every part more or
less moveable, for the purpose of respiration.$
* Masc:igni. Histor. vasor, lymphatic. Tab. xx.
f Ibid. Tab. xxi.
t Consult Portal in the Me"in. de r.Jcad. des Scienc. de Paris,'17$<)-
§ J, G. Amstein (Prxs. Oetinger)  De usir et action? timxciror. intcrcosla'. 
76
OF RESPIRATION.
   This holds good chiefly with the six pairs of true ribs be-
 low the first pair, each of which is more moveable both than
 the one above,  and in proportion to the greater length both of
 their own bodies and of their cartilaginous appendices, which
 are united by a kind  of amphiarthrosis to the margin  of the
 sternum on  each side.
   144. Between the edges of the ribs lie two strata of inter-
costal muscles,  differing in the direction  of their fibres, but
 conspiring to produce the same  motion.
   At the  base  of the thorax, the diaphragm* is subtended in
 the form of an  arch.  It is a considerable muscle, and, in the
 words of  Haller, next in importance to the heart.  Its utility
 in the mechanical part of respiration was long  since shewn,
 by the excellent experiments of Galenf upon  living animals,
•to depend chiefly on  the phrenic nerve4
   lis antagonists are the abdominal muscles,  especially the
 two oblique and the transverse.
   145.  The thorax, thus constituted,  is, after  birth,  di-
Tubing. 1769, 4to.  Theod. Fr. Trendelenburg, Jun. De stemi costarumque
in respiratione vera genmnaque motus ratione.  Gotting, 1779, 4to. Bordenave
and Sabatier, in the M6m. de t Acad, des Scienc. de Paris, 1778.
  * Hallrr, Icon. Anat. iascic. 1, T.b 1.
  B. S. Aibinus. Tab. muuculor. Tab. xiv. fig. 5, 6, 7.
  J. G. Rbderer, De arcubus tendineis muscul. progr. 1.   Gotting 1760.
4to.
  Santorini, Tab. Posth. x. fig.  1.
  \ De Anatomicis Administrationibus, L. viii.  cap. 8. The whole book is
full o'  expei in. nls on respiration.
  $ Rphr  K'U^er.  De nervo phrenico.  Lips. 1759, reprinted in Sandifort's
Thesauius, Tom. iii.
  Walter's Tab. nervor. thorac. et abdominis, Tab. 1, fig. 1, n. 1. 
OF RESPIRATION                    77
lated by inspiration,  and  subsequently reduced to a smaller
capacity by expiration.
   During the former act, the thorax is enlarged laterally and
inferiorly, so that the bodies of the six ribs mentioned above
(143) are elevated and their inferior margin drawn somewhat
outwards, and the arch of the  diaphragm at the  same  time
rather depressed  and flattened.
   I  have never observed  the inferior extremity of the  ster-
num, in tranquil respiration, to be thrust forwards, as some
have asserted. (B)
   146.  This alternate motion of the chest  continues during
health and freedom  from  restraint, from the  hour of birth
till death.  Its  object is,  that the  lungs may be expanded
to admit the air, and contracted to expel it, in perpetu.ii dter-
nation.   This alternation occurs, in an adult at  rest, about 14
times  in a  minute,—once  to  about five pulsations  of the
heart.
   147.  For man, in common with  all warm-blooded animals,
cannot long retain the inspired air, but  is compelled to dis-
charge  it, and take in a fresh supply of  this pabulum of life,
as it  always has been denominated.*  Common observation
teaches that, however pure may be the air entering the lungs,
it instantly undergoes remarkable changes, by which it is con-
taminated  and  rendered unfit for  another inspiration, unless
it is  renewed.f
  * The  antiquity of the notion that air is the pabulum vitx, is seen in the
book de Flatibus, usually ascribed to Hippocrates.  The autiior ie;<-»rds the
aliment as threefold—'victuals, drink, and air : bin the latter he calls vital,
because we cannot dispense with a perpetual supply of it, without u*i<ger to
life
  ■J-Consult Harvey's Dispute upon the necessary renovation of >'nc atrial
ucous alibilis, with the celebrated  Astronomical Professor, J. Greaves, 
 ' °                    OF RESPIRATION.

   148.  It  may be asked what are  the changes which the
 air  experiences during inspiration,  and  which  consist not
 in the loss  of elasticity, as  was  formerly  supposed,  but
 in the decomposition  of its  elements.*   For  the atmos-
 pheric air  which  we  breathe  is a  singular mixture of con-
 stituents, differing very  much  in nature  from  each other;
 and, not to mention heterogeneous matters, such  as  odorous
 effluvia, various exhalations, and innumerable others which
 are  generally present, is  always impregnated  with aqueous
 vapour, electric and  magnetic  natter, and  generally  with
 carbonic acid gas ; and is itself composed of unequal parts of
 two aeriform fluids, viz.  79 of azotic gas, and  21 of oxygen
 gas  in 100.
   149. In  the  first  place  we  know  for certain,  that  at
 every inspiration,  (the fulness  of  which varies  infinitely
 in different  men of the same age, breathing  placidly,f)  be-
 sides the quantity of  azotic gas being somewhat diminish-
 ed,^:  the  oxygen  gas  is  in  a great  measure converted into
 carbonic acid  gas, or  fixed  air; so that the air of expira-
 tion, if collected, instantly extinguishes flame and   live
 coals, precipitates  lime from lime water,  and  is  specifically
fieavier  than atmospheric air,  and  rendered  unfit  for res-
 piration ; §  it  also contains  much  aqueous vapour, which
in the latter's Description of the Pyramids of Egypt, p» 101, sq. Lond. 1646,
8vo.  Also Edm. Halley's immortal popular Discourse concerning the Mean*
of furnishing Air at the bottom of the Sea in auy ordinary Depth.  Phil. Trans.
vol. xxix. No. 349, p. 492, sq.
  * Fr. Sromeyer, Grundiss der.Theoretischen Chemie, P. ii. p. 619.
  f Consult, for instance, Abihpard in the Nordisch. Archiv.fur Naturkwide
&c. T. 1. P. i. and ii.                                            '
  * Consult, besides, Priestley and others, especially C. II. PeafF, ib  P iv
P. ii.
  To discover  how  frequently  an  animal   could  breathe the  same 
OF  RESPIRATION.                     79
is condensed in a visible form by  a  temperature  of 60° of
Fahr.*
   150.  It is therefore  probable,  that,  during inspiration,
the base of the oxygenous portion  is set at liberty,  and  being
united  with  the  arterial blood, is conveyed  throughout the
system ;   while  the carbon  and hydrogen  are  brought back
with the venous  blood  to  the right side  of the  heart, and
thrown  off like smoke, as  the ancients expressed it,  in the
lungs.f
   The  more  florid  colour  of  the   arterial  blood,^  the
darker of the venous,  and  the   ai.alogous   appearance  of
the  blood,  if exposed  to the gases  in  question,  (13)  cor-
respond  admirably  with  this  theory.    Some  difficulties,
portion of air, I took three dogs equ:d in size and Lfrength ; and to the tra-
chea of the first., by means of a tibe, I tied a bladder, containing about 20 cu-
bic inches of oxygen gas.  He died in 14 minutes.
  With the second, the bladder was filled with atmospheric air.   He died in
6 minutes.
  With the third, I employed the carbonized air expired by the second dog.
He dit-d in 4 minutes.
  Upon afterwaids examining ihe  air of the  bladder, it gave the common
signs of carbonic acid gas. The instruments which 1 tmployed are described
and illustrated by a plate in the Medit. Biblioth.  Vol.  1. p.  174. et. seq.
tab. 1.

  * J. A. De Luc. Idies sur la Me'te'orologie, torn. ii. p. 67. 229.

  ■j-Rob. Menzies, De Respiratione.   Edinb. 1790, 8vo.

  H. G. Rouppe on the  same subject.  Lugd. Batav. 1791,4to.
  J. Bostock's Versuch uber  das Athemolen. ubers.  von. A. h\ Nttlde. Erf.
1809, 8vo.
  t J. Andr. Scherer. Be-.eek dass. J. Mayow, vor 100. Jahren den Grand Zur
Antiphlogistischen Chemie und Physiologiegelegt hat, p. 104.  Edm. Godwyn's
Connexion of Life  with Respiration.   Lond. 1788, 8vo.  J. Hunter,  On  the
Blood, p. 68. J  A. Albers in the BeytrHgen zur  Anat.  und Physisjog.  der
Thiere. P. 1, p. 108. 
80
OF RESPIRATION.
indeed, remain to be  solved, v. c.  how the carbon Can be
united in the lungs with the oxygen, so as  to fly  off in the
form of carbonic acid gas. (C)*
  151.  This perpetual change of elements, occurring in re-
spiration after birth, we shall show to  be very differently ac-
complished in the foetus, viz. by means of the connection of
the gravid uterus  with the  placenta.  But when the child is
born  and capable  of volition, the congestion  takes place
in the aorta, from the obstruction in the umbilical arteries  :
the danger of suffocation from the cessation of those changes of
the blood, in regard to oxygen and carbon, (13) hitherto pro-
duced in the uterine placenta ;   the  novel impression of that
element into which the  child,  hitherto an aquatic being, is
conveyed; the cooler temperature  to  which it is now  ex-
posed, and the many new stimuli which  are now  applied,
seem  to induce new motions in  the body, especially the dila-
tation of the chest and the first inspiration.
   The lungs, being for the  first  time dilated by inspiration,
open  a new channel to the blood, so that, being obstructed in
the umbilical arteries, it is derived to the chest.
   Since the inspired  air  becomes hurtful  and  unpleasant to
the lungs by the  decomposition which it  experiences, we
would ascribe to the most simple corrective powers of nature
the subsequent motion, by which the poisonous mephitis, as
it be may called,  is expelled and exchanged for a  fresh sup-
ply.  (D)
   The consideration  of all these circumstances, especially
if the  importance of   respiration  to circulation, demon-
  * See J, Brugnatelli's Elementi di Chimica. T. 1. p. 155. T. Fr. Gmelin,
De Acidorum origineex ae're vitali adhuc dubia'm the Comment. Soc. Reg. Sc.
Gottivg. T. xm. 
OF RESWRATtOV.                     8 1
strated by the well-known experiment of Hooke,* be remem-
bered, will, in my opinion, explain the celebrated problem of
Harveyf better:}:  than  most  other  attempts  of  phvsiolov
gists (E).§
                           NOTES.

   (A) A correct notion can' scarcely  be formed  from  this
description.   The  pleura is two closed sacs, one of which is
interposed between each  lung and the  parietes of the chest,
one  portion  of the  sac adhering  to  the latter  and one to
the former;  but  the internal  surfaces  of both  portions are
always  in contact, because, if  the parietes of the thorax ex-
pand and draw  with them the external portion,  the lungs at
the same time  expand with air, and force out the  internal in
the same proportion.
  • It bears the epithet Hookian, because  it was most adorned by Rob.
Hooke. See Th. Sprat's History of the Royal Society.  Lon. 1667, 4to. p. 232.
But it was before instituted and very much praised for its beauty by  Vesali-
U9.  De c h. Fabrica. p. 824.

  | Win. Harvey De circulat. sanguin. ad T. Riolaii, p. 258. Glasgov. 1751,
12mo. and especially his Exevc de genere Animalium, p. 263. London, 1651,
4to.

  t See Theod. G. Aug.  Roose Uber das Ersticken neugebohrner Kinder, in his
Physiologisch. Untersuchugen. Brunsw. 1796, 8vo. J.D. Herholdt Devita im-
primis fatus humani, ejusque morte subpartu,  Havn. 1802, 8vo.

  § Consult,for example.Petr.T. Duoustenc De Respiratione. Lugd. 1743,4to.
p. 34, sq. Rob. Whytt on the Vital and other involuntary Motions of Animals, p,
232. Edinb. 1751, 8vo.
                                M 
82                   OF RESPIRATION.
  (B) To Dr. Carson we are indebted for the  best account
of the mechanical part of respiration.
  The substance of the lungs is highly elastic, and constantly
kept in a forced state of distension after birth by the pressure
of the atmosphere.   This is evident, as upon  puncturing the
walls of the thorax,  the lungs instantly collapse,—a circum-
stance arising from the atmospheric pressure on the one side
being counterbalanced on  the other,  so that their elasticity,
experiencing no   opposition,  becomes  effective.    During
inspiration,  the  intercostal  muscles  raise  and  draw out
the ribs, and the  diaphragm descends:  the  enlargement
of the  thoracic  cavity   is  instantly  followed  of   neces-
sity   by the  greater distension  of  the  substance  of the
lungs  from the  diminished  resistance  to the  atmosphere
gravitating  in  the  bronchiae.   The  diaphrahm   and in-
tercostal muscle  ceasing  to  act,  the  substance  of the
lungs  exerts  its  elacticity with  effect,  recovers  its for-
mer dimensions,  and drives out   the   additional  volume
of air jusr admitted, and the passive diaphragm and intercos-
tal  muscles follow  the shrinking  substance  of  the lungs,
offering, from their  relaxation, no  resistance to the atmo-
sphere  pressing  on  the  surface of  the  chest and  abdo-
men.  Thus expiration is produced.   The muscular power
of the  diaphragm and  intercostal  muscles  is  far  greater
than the elastic power of  the  lungs,  and therefore  when
exerted  overcomes   it,  producing  inspiration :  but ceas-
ing  to be  exerted,  the  elastic power gains efficiency, and
produces  expiration.    " The  contractile  power  of the
diaphragm  [and intercostal muscles)  in  conformity  with
the  laws of muscular motion,  is  irregular, remitting and
sometimes  altogether quiescent.    The  elasticity  of the
lungs, on  the other  hand, is  equal and constant.   The
superior energy  of  the  former  is balanced  by the perma- 
OF RESPIRATION.                    83
nency  of the latter.  By the advantage which  the  inferior
power, from the uniformity of  its operations, is enabled to
take of  the  remissions of  its  more  powerful antagonist,
the ground  which  had  been lost  is  recovered,  and  the
contest prolonged ; that contest  in which victory  declaring
on one side or the other is the instant death of the  fabric."
p. 223. 1. c.
   In  the common account  of respiration, the  elasticity of
the lungs  is  unnoticed, and expiration is ascribed to  the
contractions  of the  abdominal  muscles.  Now in the first
place, the elasticity of the  lungs  is of itself sufficient  for
the purpose, and in  the second,  there is no  proof of  the
necessity  of  these  muscles  in  expiration.    It proceeds
equally  well  in  cases  of  inanition, when their contraction
would rather enlarge  than diminish the  abdominal cavity,
and in experiments when they  are entirely removed from
animals.
   The beautiful contrivance in  the shape  of the thorax
deserves' attention :  by being  conical,  every  degree  of
motion  in the diaphragm  produces a greater  effect on the
size of  the  chest than could occur were it of  any  other
shape.
   The vacuum constantly threatening  in the  chest, either
from  the shrinking  of  the  lungs  or the  contraction of the
inspiratory muscles, and I may add from the  expulsion of
blood from  the  ventricles  of the  heart, will  evidently be
prevented, not only by the falling of the ribs and  the ascent
of the diaphragm in the  former  case, and  ingress of  ad-
ditional  air  into  the   bronchiae  in the latter,   but  also  by
the course of venous blood into the auricles  ; for the venous
blood being  subject to  the full  atmospheric pressure with-
out the chest will necessarily be  driven into  the  chest to pre-
vent  a vacuum ; the arterial blood is under the  same  cir-
• 
84
OF RESPIRATION.
cumstances, but the propelling  force  of  the ventricles pre-
vents its retrogression.  The atmospheric  pressure  on the
blood-vessels creates a necessity for  greater strength in the
ventricles,  as  it  impedes  the  progress of  blood from the
heart, but  it thus facilitates its return.   Thus the smaller
pressure on the heart acts by the intervention of the blood,
as an antagonist to its contracting fibres,  dilating them  when
they become relaxed.
  By the tendency to a vacuum in the cavity of  the  thorax,
what effect the heart loses by atmospheric resistance without
the chest, is exactly compensated within, and thus  on the
whole the  heart  neither  gains  nor  loses by all the various
directions of atmospheric pressure.
   In the fcetus  the case is  precisely the same, although Dr.
Carson  has  imagined it different, and thought it necessary  to
frame a little hypothesis  to reconcile circumstances.  The
foetal lungs, experiencing  no atmospheric pressure, are con-
tracted  to the utmost, and the diaphragm  suffering no stimu-
lus from the will on  account of uneasy sensation arising from
want of breath, is completely relaxed and  forced  upwards,
to remove  the vacuum, and the venous  blood  without the
thorax must, for the same  reason,  be drawn forcibly into the
right auricle, preventing the vacuum which the shrunk state
of the lungs, and the discharges of  blood from the left ven-
tricle tend to produce.
   The  cause of the  first  inspiration  appears to  be the novel
impression  of  cool  air upon the surface, for if at any time
we are  exposed to a cold wind or p.1 tinge  into  cold  water,
the  diaphragm and intercostal muscles  instantly contract,
and a  strong inspiration  takes  place.   The  blood  rushes
into the expanded lungs, and being afterwards  obstructed
when the  inspiratory  muscles cease to  act and the  elastic
lungs shrink, gives  rise to an uneasy sensation, which is in- 
                     OF  RESPIRATION.                    85
                   ■
stinctively removed by another inspiration,  and thus  respi-
ration afterwards continues through life.   The fact of  respi-
ration  commencing  before  the  chord is tied, shows that
neither the conjestion in the aorta, nor  the deficiency of che-
mical changes, is  the cause of the first inspiration.
  The elasticity of the lungs  is not sufficiently great to expel
the whole  of their air in expiration,  whence  they remain
constantly in a certain degree of  distension, and the  course
of the blood through them is never completely obstructed by
expiration.
   (C) It is now ascertained,  that no oxygen is absorbed in
respiration, but that it  goes entirely to unite with the carbon
of the blood and produce carbonic acid.  Mr. Ellis * con-
tends that the carbon escapes from the vessels  and unites
with the oxygen externally; and  my distinguished and ex-
cellent friend Dr. Prout  thinks this opinion corroborated by
a fact stated  by Orfila,t  that when phosphorus  dissolved in
oil is injected  into the blood-vessels, vapours of phosphorus
acid stream from  the mouth and nostrils,  which would hard-
ly have occurred if the acid had been formed in the vessels,
as it would probably have remained  in solution in the blood
not being volatile;—the  phosphorus was probably excreted
from the vessels in minute subdivision, and united with  the
oxygen  of the atmosphere upon coming in contact with it,
producing  phosphorous acid ;  and  the  same  may be ima-
gined  respecting  the carbonic.|   The quantity  of   carbon
discharged  amounts in an adult man to 11 oz. in twenty-
four hours, according  to  the experiments of Messrs. Allen
  * On Resfiiration.         f Toxicologic Generate.         $ Annals
of Medicine and Surgery, vol. i. p, 155   § Philos. Trans. 1808. and 1809. 
86                    OF RESPIRATION.
                                      •
and  Pepys.§  But the capacity of the lungs upon which such
calculations are founded, appears to me greatly overrated.
  The use of the nitrogen respired is unknown.  The uni-
versality of respiration or something analogous among living
beings,  and all the circumstances  attending its performance,
render it  probable, as Dr.  Prout justly remarks, that it does
something more than  discharge a little superfluous  carbon.
He considers  galvanism as an  instrument extensively used
by  the  vital principle, and as  galvanism must  be produc-
ed by the combination  of carbon with oxygen, as it is in
the battery by  the  union  of the metal  and oxygen,  one
great additional purpose of respiration becomes highly pro-
bable.
  According to Berzelius, the  colouring  matter alone  pro-
duces changes upon  the  air, and that only when  mixed with
the other  constituents of the blood.*
 Dr. Prout and Dr. Fyte have found the quantity of carbonic
acid gas experience uniform variations.  It is diminished by
mercury, tea, substances containing alcohol, depressing pas-
sions, and fatigue, and undergoes an increase from day-break
till noon, and  a decrease from noon till sun-set, remaining at
the minimum till day-break.|
  (D) On the subject of all this paragraph see note B.
  (E) The experiment  consisted  in  laying the  lungs com-
pletely bare, and supporting lite by continuing respiration ar-
tificially.   Hooke varied it bv pricking  the surface  of the
lungs, and forcing a continued stream of  air through them.
The following are the  words  of Harvey : "  It would  ap-
pear that the use of  expiration is  to purify and ventilate the
blood, by  separating  from it  these noxious and fuliginous
vapours."

 * Animal Chemistry.         t Thomson's Annals of Philosophy, 1814.
Dissert. Inaugur. 8tc. Edinb. 1814. 
OF THE  VOICE AND SPEECH.               87
                       SECT. IX.


                 OF THE  VOICE  AND SPEECH.


   152.  WE have  described the  chief use  of respiration.
We shall hereafter mention how far it contributes to the con-
version of  the chyle into  blood, and to  the support of almost
the whole  class of natural functions.   Its other  uses  are at
present to  be considered.
   And first,  respecting  the  voice.*  This takes place after
birth, and  proceeds  from the  lungs, as was observed long
ago by  Aristotle, who called  those animals only vocal,  which
breathed by means of lungs.   The voice is, properly speak-
ing, a sound, formed, by means of expiration, in  the larynx,
which is a  most beautifully constructed organ, fixed upon the
top of the  windpipe, like  a capital upon a pillar.f
   153.  The laryux is composed of various cartilages,  which
being united together in the form, as it were, of a little box,:j:
and supplied with a considerable and wonderful apparatus of
muscles,^ may be moved altogether, or separately, according
to the variations of the voice.
  * Th. Young in The Philos- Trans. 1800 P. 1.
  \ Jan.  Marg. Busch De Mechanismo  Organi vocis hujusque Functione.
Groning.  1770. 4to.
  i Soemmerring's Icones Organorum Gustus et Vocis.  Francof. 1808. fol.
  § B. S.  Albums' Tab. Muscul. Tab. X. fig. 1—15.  Tab. XI. fig. 45—48.
Tab. XII. fig. 1—7. 
88               OF THE VOICE AND  SPEECH.

   154. The part  of the  larynx  most concerned  in  pro-
ducing the voice, is  the glottis, or narrow opening of the
windpipe, having the epiglottis suspended, and, in a manner,
fixed upon it.-  It is clearly ascertained, that the air, expired
from the lungs, and striking properly upon the margins of the
glottis, becomes sonorous.
   155. But it has been disputed what changes the glottis un
dergoes in modulating the  voice.   Whether it is alternately
widened and constricted, as Galen and Dodart supposed, or
whether, according to Ferrein, the variations of voice are ef-
fected rather by the tension and relaxation of its ligaments.
   The latter,  consistently with  his opinion, compared the
larynx to  a violin;  the former, more consistently with na-
ture, to a flute.*
   Every thing considered, we must  conclude that the  glot-
tis, when sounding, experiences both kinds of changes;  since
the grave and  acute   modulation  of the voice  must  depend
very much upon the  alterations produced in the glottis  by
the  ligaments, especially the  inferior  thyreoarytenoids, (the
vocal chords of  Ferrein,) and by the corresponding modifica-
tion of the sinuses or ventricles of the larynx.]
  * Kratzenstein viewed the glottis and larynx as a kind of drum, with its
head bisected.  Tentamen de Nalura et  Charactere Sonorum Litterarum Vo~
calium.  Pretop. 1781. 4to.  I would, in  some sense, compare it to an Eolian
harp, particularly one of the description  found by Labillardiere in Amboyna.
Voyage d la Recherche de la Perouse. T. i. p. 326.
  f See some experiments made at Gottingen with the  view of settling
this controversy,  in  J. G. Ttunge's   Dissertalion De  Voce Ejusque  Or- 
OF THE VOICE AND SPEECH.
89
   156. That every degree of motion in the glottis is direct-
ed by  the numerous muscles of the larynx,  is proved by the
beautiful experiment of tying or dividing the recurrent nerves,
or par vagum,*  and  thus weakening or destroying the voice
of the animal. (A)
   157. Man and singing birds have  the power of whistling.
In the latter, it  is accomplished by  a larynx placed at  each
extremity  of the wind-pipe,  and divided into two portions.
The former though possessing a single and undivided larynx,
has learned,  I imagine, to imitate birds,  by the coarctation
of the lips.f
   158. Singing, which  is composed  of  speech and a har-
monic modulation of the voice, I conceive  to be peculiar to
man, and the chief prerogative of his vocal organs.   Whis-
tling is connate in birds; many of them  may easily be taught
to pronounce  words, and instances have been known  of this
even in dogs.   But it is  recorded, that  genuine  singing has
once  or twice only, then indeed but indifferently and with
the utmost difficulty, been taught to parrots ;  while, on the
ganis.  L. B. 175.3. 4to.  Also consult Jos. B..ilanti, in the Commentar. In-
stituli Bonon.  T. vi. Vicq-d'Azyr in the Mem. de I'Acad. des. Sc.  de Paris.
A. 1779.
  * Respecting this celebrated experiment, anciently made by Galen, con-
sult among others VV. Courten, in the  Philos. Trans.  X.  335. Morgagni.
Ep. Anatom. xii. No. 20.  P. F. Mol'melli, in  the Comment. Institut. Bonon.
Tom. iii. J. llaighton, in the Memoirs of the Medical Society of London.
T. iii.
  \ The larynx, even among the most ferocious people, is capable of imi-
tating the sounds of animals.
  Consult Nic. Wisten, Noord en oost—Tartarye ed. 2. Amst  1705. vol.  1.
p. 1G5, respecting  the southern inhabitants of New Guinea, called  Papus.
And J. Adair, in his History of tine American Indians, p. 309, respecting the
Chotkah tribe of North America.
                            N 
90                OF THE VOICE AND SPEECH.

other hand, scarcely a barbarous nation exists, in which sing-
ing is not common.*
   159.  Speech  is  a  singular modification of the voice, ad-
justed to the formation of the sounds of letters, by the expira-
tion of air through the mouth or nostrils, and in a great mea-
sure  by the  assistance  of the tongue,  applied and  struck
against  the  neighbouring parts, the  palate  and teeth in  par-
ticular,  and by the diversified action of the lipsf
  The difference  between voice and speech is therefore evi-
dent.  The former is produced in  the larynx; the latter by
the singular mechanism of the organs above described.
   Voice is  common  both  to brutes  and  man, even imme-
diately  after birth, nor is  entirely absent in those  wretched in-
fants  who  are born deaf.  But speech follows  only the cul-
ture and employment of reason, and is consequently, like it,
the privilege of man in distinction  to the rest  of animal na-
ture.   For  brutes, natural  instinct is sufficient;  but man,
destitute of this  a: d  other  means of  supporting his exis-
tence independently,  enjoys  the  prerogative of reason  and
language;  and  following,  by their  means, his  social desti-
nation, is enabled to  form,  as it were,  and manifest his ideas,
and to communicate his  wants  to others  by the  organ of
speech.
  * I have in my hands the testimony of most respectable travellers, in re-
gard, for instance,  to the  inhabitants of Ethiopia, Greenland, Canada, Cali-
fornia, Kamtschatka, &c. and therefore wonder  at the  :.ssertion of Rous*
seat;, that singing is not natural to man. Dictionn, de Musique T. i. p. 170,
Genev. 1781. 12mo.

  f See Rich. Payne Knight's  Analytical Essay on the Greek  Alphabet.
Lond, 1791,4to. p. 2.
0 
OF THE VOICE AND  SPEECH.
91
   160. The mechanism* of speech and articulation is so in-
tricate, and so little understood, that even the division of let-
ters,  and  their distribution  into classes,! is attended with
much difficulty.
   The division, however, of Ammann4 into vowels, semi-
vowels, and consonants, is very natural:
   I.  He divides the vowels§ into simple, a, e, i, y, o, u, and
mixed, a,  o, u.
   These are  formed simply by the voice.
   The semi-vowels  and  consonants  are articulated by the
mechanism of speech.
   II.  The semi-vowels are nasal, m, n, ng, (n before g, which
is  nearly related to it,) that is, the labio-nasal m; the dente-
nasal n ; and  the  gutture-nasal ng;  or oral (lingual) r, I;
that is, r with a vibration of the tongue ; or /,  with the tongue
less moved.
   III. The consonants are  distinguished into hissing (pro-
nounced in  succession) h, g, ch, s,  sch, f, v,ph; that is h,
  * Consult F. Mercur.  ab. Helmont's Alphabeti vere  Naturalis Hebraici
Delinrutio.  Sulzbac. 1657. 12mo.
  Joach. Jungii Doxascopioc Physica Minores (1662.)  4to.  Append.  Sec-
tion i. P. ii. fol. G. ii. g. 3.
  J. Wallis' Grammalica Lingua Anglicanx, cui prafigitur de loquela s. sono-
nun omnium  loqiiclarivm formatione tract, grammatico-physicus.  Ed. 6. Lond.
1765.  8vo.
  Gottl, Conr.  Chr. Storr. De Formatione hoquelte.  Tubing. 1781. 4to.
  ■j- K. G. Anton, Uber Sprache in R'ucksicht auf GescHchte der MensihcUh,
Gorlitz.  1799.  8vo.
  Er. Darwin's Temple of Nature.  AJilit. N<>: •*, p. 112.
  t His Surdus Loquens.   Amst. 1692. 8vo.  With the Dissert, de Loquela.
lb. 1700.
  §'Respecting their formation, cor.sult Chr. Theoph. Kratzenstein's  Tnui-
men, recommended above. 
92
OF THE  VOICE AND  SPEECH.
formed in the throat, as it were a mere  aspiration; g and
ch true consonants ; s, sch, produced between the teeth ; f, v,
ph, formed by the application  of the  lower lip to the upper
front  teeth :  and explosive, (which are, in a manner,  at once
exploded, by an expiration, for some  time suppressed or in-
terrupted,)  that is, k, q, formed in the throat; d, f, about the
the  teeth;  p,  b,  near  the  lips; and  double  (compound)
X, 2.
   161. We must just mention  certain  other modifications
of the human voice, of which some, as  hiccup and  cough,
belong more properly  to  pathology than  to physiology  but
are very common in the  most healthy persons; and others,
as  weeping and  laughing,  appear  peculiar .to the  human
race.
   162. Many of these are so closely allied,  as frequently to
be converted  into each other; most also are variously mo-
dified.
   In laughter there is a succession of short and abrupt ex-
pirations.*
   Coughing is a quick, violent, and sonorous expiration,  fol-
lowirg a deep inspiration, j*
   Sneezing, generally the consequence of an irritation of the
mucous membrane of the nostrils, is a violent and almost con-
vulsive expiration, preceded by a short and  violent  inspira-
tion 4
   Hiccup, on the  contrary,  is a sonorous, very  short, and
  • Fr. Lupichius De Risu,  Basil, 1738.  4to.  Traite" des Causes Physi-
ques et Morales du rire.  Amst. 1788.  8vo.
  f J. Melch. Fr.  Albrecht (Fraes. Haller.)  Experimenta in vivis Animalibui
circa tussis organa exploranaa instiluta.  Gotting. 1751. 4to.
  t Marc. Beat. L. J. Porta De Sternulatione.  Basil, 1755. 4lo. 
                OF THE VQICE AND SPEECH.               93

almost convulsive inspiration, excited by an unusual irritation
of the cardia.*
   Weeping consists of deep  inspirations, quickly alternating
with long and occasionally interrupted expirations.f
  Sighing is a long and deep inspiration, and the subsequent
expiration is sometimes accompanied by  groaning.\
   Nearest  in relation to sighing is gaping^ which is pro-
duced by a full, slow, and long inspiration, followed by  a
similar  expiration, the jaws at tne same time being drawn
asm der, so that the air rushes into the  open fauc! s and the
Eustachian tubes.  It occurs from the blood passing through
the lungs  too  slowly; v. c. when the pressure of the air is
diminished, as upon very high mountains.   A peculiar fea-
ture of  gaping  is the propensity it excites  in others to gape
likewise ; arising, no doubt, from the recollection of the plea-
sure it produced.
                          NOTE.

  (A) M. Le Gallois has ascertained that  the  division of
the recurrent  nerves frequently  proves  fatal  in  animals,
and  that  its  effect  is  to paralyse the  arytenoid  muscles,
thus relaxing  the  ligaments of the glottis, the aperture  of
which  is  therefore  diminished.   This effect, however, va-
* C. J. Sig. Thiel De Singulter. GoUing. 1761. 4to.
f J. F. Schreiber De Fletu.  L B. 1728. 4to.
$ 1) \. C. lmm Beidoi De suspirio. Basil. 1756. 4to.
$ Just. Godofr. Gunz (Prxside Walthero) De Oscitatione. Lips. 1738. 4to. 
9.4 ^            OF  THE VOICE AND  SPEECH.

ries  with the kind and age of the animal.  The danger di-
minishes as the animal is older ; and after a certain age, lit-
tle inconvenience follows.*
  The inferior ligaments of the glottis  are  the chief source
of the voice, for  in  blowing into the  trachea  and larynx of
an animal  a slight sound only is heard, unless you approxi-
mate the arytenoid  cartilages  to each other,  when a sound
somewhat  analogous to the voice of the animal will  be pro-
duced, and more acute in proportion to their approximation:
and it will  be seen, at the same time, that the  sound is caus-
ed chiefly by the vibrations of the inferior ligaments of the
glottis.   Again, an   opening below the inferior  ligaments
destroys the voice, while  one above it, even  through the epi-
glottis, superior ligaments  and arytenoid  cartilages,  has  no
such effect.  In grave  tones, the whole  length of the  infe-
rior  ligaments  may  be  seen in  a  dog to vibrate; in  more
acute, the posterior part only;  and in very acute, merely the
arytenoid  extremity,  the opening  of the  glottis being  of
course lessened in  the  same  proportion.  These  circum-
stances depend upon the thyro-arytenoid muscles, which run
on each side from the arytenoid to the thyroid cartilage and
from the lips of the  glottis (and indeed also the superior liga-
ments), being covered  by an aponeurosis, and this  by the
mucous membrane.  In  proportion as these  contract, they
become shorter and  more tense, and lessen the mouth of the
glottis; but the complete closure of the  glottis at the  back
part is  effected by  the arytenoid  muscles,  which  connects
the two arytenoid  cartilages.f   As all these  are voluntary
  * Experiences sur le Principe de la Vie.  Far M. Lu Gallois.
  ■j-These  observations of M. Majendie's, ,<;■<■ contradictory to those of M.
Le Gailois. 
                OF  THE VOICE AND  SPEECH.               95

muscles, the  division  of their  nerves destroys the voice.
The division of the recurrents, which  supply the arytenoid
muscles, is sufficient for this purpose; but, in some instances,
a sound still remains similar to what may be produced  after
death by blowing through the larynx, after approximating the
arytenoid cartilages, and must be owing to the action of the
arytenoid muscles, which are supplied not  by the recurrent
but by .the laryngeal nerves.   As these muscles are the  chief
means of contracting the posterior part of  the  glottis, and
producing the most  acute sounds, the division of the laryn-
geal nerves destroys almost all acute sounds and renders the
voice grave.
  " It  is therefore  evident  that the larynx represents a reed
with two plates, the tones of which  are acute in proportion
as the  plates are short,  and  grave  in proportion as they are
long.  But  although this analogy is just, we must not  ima-
gine that there  is a perfect identity.  In fact,  common reeds
are composed of rectangular plates fixed on  one side and free
on the three others, while the vibrating plates of the larynx,
which  are also  nearly  rectangular, are  fixed  on three sides,
and free on  one  only.   Besides,  the tones of common reeds
are made  to ascend or descend by varying their  length ; but
the plates of the larynx vary only  in breadth.  Lastly, the
moveable  plates  of the  reeds of musical instruments cannot,
like  the ligaments of the glottis, change  every moment  in
thickness  and elasticity."*   The elongation and shortening
of the  trachea and of the cavity between the glottis and the
lips, and the  changes of the  epiglottis and of the  ventricles
of the larynx, must affect the voice.
* Precis FJimtntaire de Physiologie, par. F. Majendie.  T. 1. p. 216. seq. 
96
OF ANIMAL HEAT.
                        SECT.  X.


                      OF ANIMAL HEAT.


   163. M.AN, the  mammalia, and  birds,  are  distinguished
by the natural temperature* of their bodies greatly exceed-
ing that of the medium in  which  they, are  accustomed to
exist.   Man is again distinguished from these classes  of ani-
mals, by possessing a much lower temperature than th^y; so
that in this climate it is about 96°  of Fahr.  while in  them,
and especially in birds, it is considerably higher.f
   164. This  natural temperature in  man, is  so constant,
equable,:):  and perpetual,  that, excepting  slight  differences
from variety of constitution, it varies but little, even  in the
coldest climate and under the torrid  zone.   For  the opi-
nion of Boerhaave, that man  cannot live  in  a temperature
  * W. B. Johnson's History of Animal Cliemistry. Vol. iii. p. 79.
  j-The torpid state of some animals during winter,  is of course  an ex-
ception to this.  Most of the functions cease or languish considerably, and
the animal heat is  reduced nearly to  coolness.  This well-known circum-
stance prevents me from acceding to the opinion of the verj icute J. Hunter,
—that the animals  when we call warm blooded, »hould rather be called
animal* of a permanent heat undo" ail temperatures.  On the Blood, p. 15.
  i J. B. Van Mons in the Journal de Physique. T. lxviii. 1809, p. 121. 
OF ANIMAL HEAT.
9.7
 exceeding his own, has been refuted since the admirable ob-
 servations* of H. Ellis, the  celebrated traveller and formerly
 the captain of the George,  by the remarkable experiments]
 of many excellent physiologists.^   This striking prerogative
 of man is  evinced by his being  restricted  to no climate,  but
 inhabiting every  part of the  earth from Hudson's bay, where
 Mercury freezes, and from Nova  Zembla, to the  scorching
 shore of Senegal.
   165. The explanation of this  circumstance is equally sim-
 ple and natural,  and  founded on the doctrine which  makes
 the lungs the grand receivers, or focus, and the decomposi-
 tion of the oxygenized  portion of the air (148) the source
 or fomites of our heat.
   166. For,  as,the oxygenous part of the inspired air is
 decomposed  in the  air  cells  of the lungs, in  such a way
 that its  base, which by its union  with latent caloric was
 before aeriform,  now separates  from  this caloric,  it would
 appear  that,  by this decomposition, one  portion of the  ca-
 loric is rendered  sensible in  the  bronchiae, while  the  other
enters  in a latent form  into  the  blood, circulating in  the
  * Philos. Trans, vol. i. P. ii. 1758.  Am. Dantze had previously made the
observation in regard to brutes. Exper. Calorem Animalem Spectantia. Ludg.
Bat. 1754, 4to.  Also Benjamin Franklin's Experiments and Observations on
Electricity.   Lond. 1769, 4to. p.365.
  j- Duhamel and Tillet, in tlie Mem. de I'Acad. des Scienc. de Paris, 1704.
  Blagden and Dobson. Philos. Trans. 1765.
  t The heat of the weather, even in Europe, occasionally exceeds our natu-
ral temperature.  This was  the case on the third of Aug. 1783, at noon)
when I was on the Lucern Alps, in company with the excellent Schnyder de
Wirtensee. The thermometer in the shade stood&bove 100° Fahr. and when
applied to the bodv, invariably sunk to 97°.
                             o 
•J 8
OF ANIMAL HEAT.
innumerable  and  delicate  net-works of  the pulmonary ves-
sels.*
   167. When the oxygenized blood thus charged with latent
heat circulates through the aortic system, it acquires carbon
in the small vessels and sets  free  much of  the latent heat
which it had received ; in  this way is  our animal heat princi-
pally produced.f
   168. Its production and regulation, however, appear much
influenced  by the  secretion  of fluids from  the  blood, both
those  which are  liquid and  destined to solidify by assimi-
lation  and  nutrition,  and  those  which   are   permanently
elastic.
   169. Since these  changes are effected by the energy  of the
vital powerst the great influence of these' upon our tempera-
ture must be easily perceived4                           ,
  * See Lichtenberg's Animadversions upon this part of Crawford's Theory,
in his notes to Erxleben'a Anfangsgr. der Naturlehre. p. 447. ed. vi.
  f Hence the constant coldness of those wretched beings who l.ibou;- under
the blue disease, which arises from a mal-conformation of the heart.  Some-
times the septa of the heart are imperfect, sometimes  the aorta arises with
the pulmonary artery from the right  ventricle, as in the tortoise.   In such
instances, the chemical changes cannot take place in the lungs.  Among
innun.erable instances of this lamentable disease, suffice it to quote J. Aber-
neiii >'.-. Surgical and Physiological  Essays. P. ii. p.  158, and Fr. Tiedemann.
Zoologie.  T. i p. 177.
  f I have formerly treated of the influence of the nervous system upon ani-
mal heat, in my Specim n Physiologia  ComparaUe Inter Animantia CalidiCr
JPngidi Sanguinis, p. 23.
  See the s;»me confirmed by many arguments in Magn. Strom's Theoria In-
flammationis lioctnme de Colore Animali Superstructa.   Havn. 1795, 8vo. p.
30, sq. and by the much lamented Roose,  in the Journal der Erfndungen, &c.
T.v.p. 17.                                                   .  i
  Consult also Dupuytrem  in the  Analyse des Travaux de l'InstitutK 1807,
p. 16. 
OF ANIMAL  HEAT.
99
   170. Many arguments  render it probable, that the action
of  the minute vessels, and the conversion of oxvgenised in-
to carbonised  blood,  are  dependent upon the varied excite-
ment or depression r f the vital principle.
   For  the remarkable phenomena of  the  stability  of our
temperature,* (proved by the thermometer,  and not  by the
sense of touch, which may be fallacious,)—that it is scarce-
ly  increased  by the  heat  of summer, or diminished by  the
cold  of winter, but  found sometimes even  to increase on
immersion in cold water,f demonstrate that the action of the
minute vessels  varies  according to the temperature of the
medium in which we are placed : so  that, when exposed to
a low temperature  (by which their  tone  is  probably  aug-
mented) more oxygen is  exchanged  for  carbon and more
heat evolved;  while  in  a high ;ind debilitating  temperature
this exchange is diminished, and less heat evolved4
  171.  The corium which covers the body and  the  internal
surface of  the alimentary  canal, eminently contributes, if we
are not much mistaken, to regulate our temperature.   For
both these organs are supplied with an  immense number of
blood-vessels,  being analogous  in this respect to the lungs,
and are so intimately  connected with the lungs, by means of
sympathy,§ as  in some degree  to  perform a part  and  oc-
  * See Crawford in the Philos. Trans, vol. Ixxi. p. ii.
  ■j- G. Pickel's Experimenta Physico-Medica de Electricitate et Colore Ani-
malt. Wirceb. 1788, 8vo. p. 91. sq.
  \ C. Ferd. Becker De Effectibus  Galons et Frigoris Extend in c. h. (iott.
1802, 4to. and Wm. Fr. Baur On the same subject, ib. eod. fboth hcnoured
vfith the Royal Prize.J  Mich. Skjelderup. Dissert. Sistens Vim Frigoris in-
citantem.  Hafn. 1803, 8vo.
  § .1. Chr. Goesciien. (Prses.  Ph.  Fr. Mfckel)  Pulmonum cum Cute 
100                 OF ANIMAL HEAJ.
casionally the whole of some  of their  functions  in thier
room.   This is exemplified in adults labouring under nearly
total consumption, or other violent affections, of the lungs,
and nevertheless  existing for  a  length of time, almost with-
out respiration.*
  172. This opinion respecting the  action of the cutaneous
vessels  in exciting,  moderating,  or almost extinguishing
our  heat, receives  much  support from  the  physiological
and  pathological facts of  some parts being frequently of
a  higher or lower  temperature than  the  rest of the  sys-
tem.
   Thus we  must attribute the coldness of  the dog's nose
to  the  specific  action of  its  own  vessels  being  modified
differently from that of the rest; so on the other hand, the
burning' sometimes of the cheeks and sometimes of the palms
of the hands in hectic fever, to the locally  increased action
of the vessels; not to mention other phenomena of the same
description, v. c the heat of  the genitals during the venereal
oestrum, and the irresistible  coldness of the feet  in certain
diseases.
   173. The alimentary canal is the only internal part besides
the lungs, exposed to  the contact of the atmosphere.   There
is scarcebjroccasion  to prove  that  it  is so  exposed, and that
we swallow a considerable  quantity of air.
   The air, when swallowed, is decomposed in the stomach
and intestines, so that, during  health, it soon loses its  elas-
tic form : not, however, when the capillaries of the canal are
debilitated, or when it exists in too great quantity.
   The extraordinary congeries of blood-vessels in the intes-
Commercium. Hal. 1789. 8vo.  But especially J. D. Brandis.  Pathologie.
Hamb. 1808, p. 316, sq.
  * See, for instance, Tacconi  in the Comment. Instit. Boniniens.  Vol. vi
p. 74. 
OF ANIMAL HEAT.
101
.tines, on their internal surface which is usually believed
equal to the external surface of the body, agrees  very  well
with this idea. (A)
                            NOTE.

      (A)  No phenomenon in living bodies is more remarkable
   than their peculiar temperature, and no one was  more diffi-
   cult solution before the progress of modern chemistry.
      If two different bodies are placed in a temperature, higher
   or lower than their own, for a certain  length of time, they
   will at the end of the period, be found not of the same, but
   of different temperatures.   That which has the higher tempe-
   rature, is  said to have a  smaller  capacity for caloric; that
   which has the lower, a greater  capacity.  To raise  the for-
   mer to a given temperature, therefore, requires less heat than
   to raise the  latter to the same degree.
      The temperature of solids is more easily affected by a given
   quantity of heat,  than that of fluids, and  the temperature of
   fluids dian that of aeriform bodies :  or in other words, solids
   have  a smaller capacity for caloric, than fluids, and fluids
   than aeriform bodies.    If, therefore, a solid becomes fluid,
   or a fluid aeriform, it absorbs a great quantity of heat, though
   its temperature remain  precisely the same.   And the con-
   verse holds equally good,—if an aeriform  substance becomes
   liquid, or a liquid solid, the heat which  it before contained is
   now (from the diminished  capacity  of the body) much more
   than sufficient for the  temperature which before existed, and
$  the temperature of the body accordingly rises.
     In  respiration, the dark  blood of  the  pulmonary artery
   ftarts with a portion of its carbon,  and  acquires a  florid 
 103                 OF ANIMAL HEAT.

 hue.  This carbon  unites with the  oxygen of the inspired
 air, and forms carbonic acid, which is expired with the other
 constituent of the atmosphere,—nitrogen or azote,—which ap-
 pears to have experienced no change from inspiration.
   Dr. Crawford rendered  it probable, by his experiments,
 that the  arterial  blood has  a larger  capacity  for caloric
 than  the  venous;  and common  air, than  carbonic  acid
 gas.  When,  therefore, the  carbon  of  the venous blood
 unites with the  oxygen of the air and  forms carbonic acid,
 the less capacity of this than common air for caloric, must
 cause an  increase  of temperature, but  the  blood  having
 changed  from   venous to  arterial, has acquired a  greater
 capacity  than before, and absorbs the  heat given  out by
 the carbonic acid.  The blood, of  course, does not become
 warmer,  because  the heat  is  not more than sufficient to
 render its temperature equal  to  what  it was previously;
 and indeed it is not  quite sufficient for this, for the  arterial
 blood of the pulmonary veins is generally two degrees lower
 than that  of the pulmonary artery.
   The body in this way acquires a fund of heat, and yet the
 lungs, in which it is acquired, do not experience  any eleva-
 tion of  temperature.
   The arterial  blood,  charged with  much   heat which is
 not sensible, circulating through the small vessels, becomes 'j
 venous,—acquires a  dark  hue, and  its capacity  for heat is
 diminished ;  consequently its temperature rises  : the heat
 which was previously latent,  is, from the decrease of capa-
 city, sufficient  to  raise its  temperature, and is  evolved.
 In this mode, the loss of heat which occurs from the inferior
 temperature in  which we live, is compensated.   The fK:sh
supply is  taken  in at  the lungs, and brought into  use in the
 minute vessels. 
OF ANIMAL HEAT.
103
   Of  late,  this theory has  been  brought  into  discredit.
 All experiments upon the  capacities of  bodies  for  heat, are
 very delicate and liable to  error; and the opinions of Craw-
 ford on this point, with respect to the gases, have  been de-
 nied by M. M. de la Roche and Berard,  and by Dr. Davy,
 ■with respect to arterial and venous blood.*
   Mr. Brodie cut of the  communication between the brain
 and lungs of animals, and continued respiration artificially.-}-
 The usual chemical changes continued in the lungs upon ihe
 blood, nevertheless the temperature of the animals diminish-
 ed, and even  more  rapidly than if the  respiration had not
 been continued, owing, he says, to the succession of cool air
 sent into the lungs.  He therefore  concludes, that  animal
 heat depends much more upon the nervous energy than upon
 the chemical changes of the blood.  But Le  Gallois asserts,
 that under artificial respiration the  temperature  falls, if every
 part remain uninjured.
   Many circumstances  favour the doctrine  of Crawford.
 In high temperatures we  have less necessity for the  evolu-
 tion of heat by the chemical changes of  the  blood  and air ;
 whereas, in low temperatures, as  more  heat is  required  to
 sustain the natural  degree  of temperature,  the  chemical
 changes are more necessary ; accordingly, in  very high tem-
 peratures, the arterial  blood remains arterial,—is as florid in
 the veins as in the arteries, and the inspired air is less vitia-
 ted ; in low temperatures the  venous blood is extremely
 dark, and the inspired air more vitiated.:}:
   Dr.  Crawford states, that the chemical process of respira-
tion may,  in  certain  cases,  be the  means of  cooling the
body.   If  the  pulmonary  exhalation   is  in  very  great
* Philos. Trans. 1814.         f Philos. Trans. 1812.
t Crawford on Animal Heat. P. 387, sq. 
104
OF ANIMAL HEAT.
 abundance, it will carry  off so much of the heat given out
 during  the change of the oxygen into, carbonic acid, that
 there may not be sufficient to saturate the increased capacity
 of the  arterial blood; this will therefore absorb heat from
 the system, as it passes along, till its temperature equals that
 of the other parts.*
   The temperature is also regulated by the degree of per-
 spiration, and the momentum of the blood, &c.   In propor-
 tion as  more vapour transpires from the skin, will more heat
 be carried off: and as the sum of the quantity and velocity
 of blood in any part is greater,  the temperature of that part
 will be  higher.  Whether Crawford's  theory be correct or
 not, the production of animal temperature must still  be  as
 evidently a  chemical  process  as changes  of temperature
 among inanimate bodies.   But this does not prevent it from
 strictly  deserving the epithet vital, because it is regulated by
 the vital powers of the system, although through the instru-
 mentality of chemical  changes.   If the  high  temperature  of
 an inflamed part  is owing to the increased momentum of the
 blood, yet this increased momentum is produced by the vital
 powers.   As there  is less vigour in old than in  young per-
 sons, and in remote parts than in those which are near the
 centre of circulation, the momentum of  the blood is less  in
 the old than the  young, and  in  parts  remote than in parts
near the heart ; hence  the  temperature of the old  falls short
of the temperature of the  young, and is stated to be in all
persons  lower  in proportion to the distance of parts from the
centre of the circulation.f
* L. c. p. 388-         fDr. Davy,'Philos. Trans. 1814. 
OF THE CUTANEOUS PERSPIRATION.
105
                        SECT. XL


               OF THE CUTANEOUS PERSPIRATION.


   174. The functions  of the skin, which affords a cover-
 ing to the body, are so extremely various, that they  cannot
 all be easily described  with advantage  in one chapter, but
 each will far more conveniently be considered under that class
 of actions to which it belongs.
   For, in the first place, the skin is the organ of  touch, and
 will be examined in this view, under the head of animal func-
 tions.
   It is an organ of inhalation, and in this point of view be-
 longs to  the absorbent system, to be spoken of  among the
 natural functions.
   It is likewise  the organ  of perspiration, and  on  this ac-
 count related in .many ways  to  the  function of respiration,
 and may, we think, very properly follow it in this place.
   175.  The skin consists  of three  membranes.   The  Cori-
um, internal; the cuticle, external;  and the reticulum, inter-
 mediate.
   176.  The cuticle or epidermis,* forms the external cover-
ing  of  the  body, is separable into lamellae,! and exposed
  * Al. Monro Primus.  Oratio de Cuticula Humana.  Opera. English Edi-
tion.  Edinb. 1781, 4to. p. 54, sq.
  ! Among others, consult J.  Mitchell, in the P/ulos. Tram. Vol. xliiip.
111.
                            P 
106             OF THE CUTANEOUS  PERSPIRATION.
to the  atmosphere, the  contact  of which  can be borne by
scarcely any other part, if you except the enamel of the teeth.
For this  reason, internal cavities and the canals  which com-
municate with the surface for  the purpose of admitting air,
especially the respiratory passages, and the whole  of the ali-
mentary canal, the tongue, the  inside  of the cheeks, the fau-
ces, and the organ of smell, are covered by a fine epithelium,
originating from the epidermis.*
   177. The texture of  the  epidermis is  extremely simple,
destitute of vessels, nerves,  and of-true  mucous  web, and
consequently  but  little  organized  ;  very  peculiar,  how
ever,!  remarkably  strong, considering  its  pellucidity  and
  * Abr. Kaau, Perspiratio Dicta Hippocrati, p. 7.
  Lieberkuhn, De Fabrica Villor. Intestin. Tenuium, p. 16.'
  Cruikshank's Expts. on the  Insensible Perspiration, p.  5
  Rudolph, Reiscbemerkungen.  T. i. p. 29,140.
  Jens. W. Neergaard, Vergleichende Anat. der  Verdauungswerkzeuge,?. 21,
& albi.
  f The very dense epidermis of some immense animals consists of vertical
fibres, which, in arrangement, somewhat resemble tfie structure of the
Boletus  igniarius.  Its internal surface is porous and penetrated by the fi-
laments, in appearance silken, of the subjacent corium.  This is remarka-
bly exemplified in a preparation now before me, taken from the skin of the
balxna mysticetus.  The human cuticle, in certain diseased states, exhibits j
the same appearance as in the Englishman called the Porcupine Man, who
laboured under a cuticular complaint which he transmitted to his children
and grand-children.   Vide W. G. Tilesius' Beschreidung und Abbildung der
beidensogenannten Stachelschwein-Mensc/ien (Porcupine Men.) Altenb.jl802,
fol.
  The innumerable polyedrical papillx and horny warts which I witnessed
tipon every part of the skin of these brothers, excepting the head, the palms
of the hands and the soles of the feet, bore some resemblance to the skin of
the elephant, especially about the vertex and forehead of the amimal. 
OF THE CUTANEOUS PERSPIRATION.
107
delicacy,  so  that   it  resists for  a  great  length  of time
maceration,  suppuration, and other modes  of  decay, and
is  reproduced more  easily  than  any other of  the similar
parts.
   178. It is completely sui generis, somewhat like  a horny
lamella, and adheres to the subjacent corium by the interven-
tion of a mucus, and by numerous very delicate fibrils, which
penetrate the latter.*
   The pores which Leuwenhoek imagined in  it, do not ex-
ist ;  but it allows a very ready passage to caloric,  carbon,
hydrogen, and  to  matters immediately  composed of these,
v. c. oil.
   179. The importance of the cuticle to  organized systems,
is  demonstrated by its universality in the animal and ve-
getable kingdoms ; and by   its being distinctly observable
in the embryo from the third  month  at latest after concep-
tion.
   180. The  inner  part of  the cuticle  is  lined by a fine
mucous membrane, denominated from  the opinion of its
discoverer,  reticulum Malpighianum,  and by   means of
which" chiefly the  cuticle is  united  more firmly  to the
corium. f
   Its nature is  mucous, it  is very soluble, and, being thicker
in Ethiopians,  may be completely separated  in them both
  Similar also are corns, and the brawny cuticle of the feet, in those who
walk barefooted. Vide Carlisle on the Production and Nature of Corns in
the Med. Facts and Observations. Vol. vii. p. 29.
  * W. Hunter, in the Med. Observations and Inquiries, vol. ii. p 52, sq. tab.
i. fig.  1, 2.  The conjecture of this eminent man, that the fibrils excrete
(he perspirable matter, is, I think, improbable.
  f  Jknc I have found the Epidermis of Albinos  separate easily by the
heat of the sun ; whereas in negroes, it scarcely does so on the application
of a h)'-U~r.  C. F. Mitchell, 1. r. p. 108. 
108          OF  THE CUTANEOUS  PERSPIRATION.
from the corium and cuticle, and made  to appear as  a true
distinct  membrane.*
   181. Our colour resides in it.   In all persons the corium
is white, and in almost all the cuticle white  and semi-pellu-
cid ; in Ethiopians, indeed, alone, it inclines  to grey.   But
the mucous  reticulum varies  after birth, with age, mode of
life, and especially with difference of climate.
   Thus among the four varieties into which  I would divide
the human race,  in the first, which may be  termed Cauca-
sian, and embraces  Europeans, (except  the  Laplanders and
the rest of the Finnish race,)  the western  Asiatics, and the
northern Africans, it is more or less white-
  In  the second, or Mongolian, including the rest of the Asi-
atics,  (except the  Malays of  the peninsula beyond the
Ganges,) the Finnish races of the north of Europe, as the
Laplanders,  &'c. and the tribes  of Eskimaux diffused over
the  north of  America,  it  is yellow,  or resembling  box
wood.
   In the third, the Ethiopian, to  which the remainder of the
Africans! belong, it is of a tawny or jet black.
   In the fourth, or American, comprehending all the  Ame-
  *  B. S.  Albinus De sede & Causa Colons AZthiopwnz et Coeteror-  Homi-
num.  Lugd. Batav. 1737, 4to. fig. 1.
  Sam. Th. Soemmerring  Uber  die kdrperl.  Verschiedenh. des NegeTs vom
Europiier.  Ed. 2. p. 46. sq.
  Some even of the moderns have assigned many lamina, and even  diffe.
rent kinds of lamina,  to the reticulum; as Lieutaud in  his Estais Anato-
miques, p. 103. ed. 1766 ; and Cruikshank, 1. c. p. 43, 99.
  Others make it organic.  Vide Mich, Skjelderup, 1. c. p. 93.
  ! Jo. Nic. Pechlin, De Habitu et Colore Mthiopum, qui Vulgo et Nigritat.
L. Kilon. 1677, 8vo.  Camper's oration on the same subject will be found in
his kleiner  Schriften Vol. i. P. 1. p. 24—49. 
             OF THE CUTANEOUS  PERSPIRATION.            109

ricans, excepting the Eskimaux, it -is almost copper colour-
ed, of a dark orange or ferruginous hue.
   In  the fifth, or Malaic, in which I include the inhabitants
of all the islands in the Pacific Ocean, and of the Philippine
and Sunda, and those  of the peninsula of Malaya,  it is more
or less tawny, between the hue of fresh mahogany and that
of cloves or chesnuts.
   All these shades of colour, as well as the  other character-
istics of nations and individuals,  run so insensibly into one
another, that all division and classification of them must be
more or less arbitrary.
   132.  The essential  cause of the colour of the Malpighian
mucus,  is,  if we mistake not, the proportion of carbon which
is excreted together with hydrogen from the corium ; and in
dark  nations being very copious, is  precipitated upon the
mucus and combined with  it.*
   183.  The corium, which is covered  by the'reticulum and
epidermis, is a membrane,  investing the whole body and de-
fining its surface ; tough; very extensible ; of different degrees
of thickness ; every where  closely  united, and, as it were, in-
terwoven  with the mucous tela,  especially externally, but
more loosely on its  internal surface,  in which,  excepting in
certain parts, we generally  discover fat.
   184.  Besides  nerves and absorbents,  innumerable  blood
  * I have given this opinion  at some length in my work, De Gen. Human
Varietate Nativa, p. 122, sq. ed. 3. Some eminent chemists accord with me,
among whom suffice it to mention the celebrated Davy, in the Journals of the
Royal Institution, vol.  ii. p. 30.  " In the rete mucosum of the African, the
carbon becomes the predominant principle ; hence the blackness of the ne
gro."  W. B. Johnson, 1. c. vol. ii. p. 229. 
110
OF THE  CUTANCOUS PERSPIRATION.
vessels  of which we shall speak  hereafter, penetrate to  its
external surface, upon which they are shewn, by minute in-
jection, to form very close and delicate net works.
  185.  A vast number of sebaceous follicles  also are dis-
persed  throughout  it, which  diffuse over the skin ah oil,*
thin, limpid, and not easily drying,! altogether distinct from
the common sweat,. and from that which possesses an oduor
resembling the odour of goats, and is peculiar to certain parts
only.
  186.  Lastly,  almost every part of the corium is beset with
various kinds of hairs,!  chiefly short and  delicate, more or
less downy, and found nearly every where  but on  the palpe-
brse, penis, the palms of the hand, and the soles of the feet.
In  some parts,  they  are long and destined for peculiar
purposes ; such are the capillamentum, the  eye-brows, the
eye-lashes,  the  vibrissae, mustachios, beard,  and the  hair of
the arm-pits and pudenda.
  187.  Man  is, generally speaking, less  hairy than  most
other mammalia.   But, in this respect, nations differ.  For,
not to mention those nations who to this day carefully pluck
out their beard or the hair in other parts,  others appear natu-
rally destitute of hair; v. c. the Tunguses and Burats; on
the other hand, creditable travellers assert, that some  inhabi-
tants of  the islands in the Pacific and Indian Ocean,  are re-
markably hairy.§
  * Chr. Gottl. Ludwig, De Humore Cutem Inungente.  Lips. 1748, 4to.
  ! Lyonet, I^ettre d M. Le Cat. p. 12.
  i Jo. Ph. WithofF, De pilo Ifumano, Duisb. 1750, 4to.  Compare the Com-
mentar. Socient. Gotting. Vol. ii.
  Job. Baster, Verhandel. der Maatsch. te Haarlem, T. xiv. p. 382.
  § De Generis Human. Variet. Nativ. p. 29. 
              OF THE  CUTANEOUS PERSPIRATION.           1 1 1

   188.  Nor  is  there  less variety in the length, flexibility,
colour, and disposition to curb both in  each  class of  men
enumerated above  (181),  and in  individuals, especially the
Caucasians;  v.  c.  the hair  of the  head in  the  Caucasian
variety is rather dingy, or of a nut  brown,  inclined on one
hand to yellow,  on the other to  black; in the Mongolian
and  American, it is black, stiffer, straight, and more sparing;
in the  Malay, black,  soft, curling, thick, and abundant; in
the Ethiopians,  black  and  woolly; in individuals,  especially
of the Caucasian variety, there are great  differences, but
chiefly in respect to temperament,  which is found intimately
and  invariably connected with the colour, abundance, dispo-
sition to curl, &c.  of the hair;* and there  also exists  a re-
markable correspondence between  the colour of the hair and
of the iris.
 .  189. The direction  of the hairs  is  peculiar in certain parts,
v. c. spiral on the summit of* the head, diverging upwards on
the pubes, on the exterior of  the  arm, as is commonly  seen
in some  anthropomorphous  apes,  (v. c. in the satyr and tro-
glodys,) running in two opposite directions towards the elbow,
i. e. downwards from  the  shoulder, upwards from the wrist;
to say nothing of the eye-lashes and  eye-brows.
   190.  The hairs  originate from the inner surface of tht
corium,  which abounds in  fat.   They  adhere  to  it pretty
firmly,!  by  a carious bulb,  consisting  of a  double  invo-
  * Galen, Ars Medicinalis, p. 211—235. M. Ant. Ulm.  Utems  Muliebris
p. 128, et alibi. Lavater, Fragmente, T. iv. p. 112.
  !1 suspect that the bulb is intended for support rather than for nourish
ment, from this  circumstance, that the locks of hairs sometimes found in
meliccra and steatomata of the omentum and ovarium, some of which I hav^ 
 112           OF  THE CUTANEOUS  PERSPIRATION.

lucrum ;* the  exterior vascular  and oval, the interior cylin-
drical, apparently continuous with the epidermis,! and sheath-
ing the elastic filaments of which  the  hair  is composed, and
which are generally from five to ten in each.
   191. The hairs  are almost incorruptible, and always anoint-
ed by an  oily halitus.  Of all parts they appear most truly
electrical.  They are very easily  nourished, and even repro-
duced, unless where the skin is diseased.
   192.  Besides the  functions ascribed to the integuments in
the former Section, must  be  enumerated  their  excretory
power, by which foreign and injurious matters are eliminated
from  the  mass of  fluids-!
  This is exemplified in the  miasmata of exanthematic dis-
eases, in the smell of the skin after eating  garlic musk, &c
in sweat and similar phenomena.
 . 193. What is most worthy our attention, is the transpira:
tion of  an aeriform  fluid, denominated, after the very acute
philosopher  who  first  applied  himself  professedly  to in-
vestigate   its  importance,  the  perspirable  Sanctorianum,§
and  similar  to what is expired  from the  lungs. If   It  like-
now before me, are usually destitute of bulbs, because they are not fixed, but
lie naked in the honey-like fatty matter.
  *Duverney, Ouvres Anatomiques, Vol. i. Tab. xvi. fig. 7, 9—14. Tab. xvij.
fig. 3, sq.
  ! B. S. Albinus, Annotal. Academ, L. vj. Tab. iij. fig. 45.
  t Hence the danger of contagion from hairs, to which miasmata very tena-
ciously  adhere for a great length of time.  Vide Cartwright's Journal of
Transactions on the Coast of Labrador, vol. i. p. 273, vol. ii. p. 424.
  § Ars Sanctor. Sanctorii, De Statica Medicina Aphorismor. sanctionibus vij.
Comprehensa. Venet 1634, l6*o.
  DC. de Milly  and  Lavoisier, Memoires I'Acad.   des   Sc.  de  Paris, 
               OF THE  CUTANEOUS PERSPIRATION.           113

wise is composed of various proportions of  carbon,*  nitro-
gen, and hydrogen,! precipitates lime from its solution, and
is unfit to support either flame or respiration.
   194. The  sweat, which  seldom  occurs  spontaneously
during health and rest, unless in a high  temperature, appears
to arise from  the perspirable  matter  of  Sanctorius being
too much increased  in quantity  by  the  excited action of
the cutaneous vessels,  and from its hydrogen  uniting with
the oxygen of the atmosphere and assuming the liquid form.
   195. Upon the same  hydrogen, variously modified by the
accession of other elements and constituents, would  seem to
depend the natural and  peculiar odour  perceived in the per-
spiration and sweat of certain nations and individuals.!
   196. The quantity  of matter perspired from the integu-
ments which, in a well  grown  adult,  are equal to 15 square
feet,  cannot  be accurately estimated, but is probably about
two pounds in 24  hours.§ (A)
1777, p. 221, sq. 360, sq. J. Ingenhouz, Expts. upon Vegetables. Lond. 1779,
8vo. p. 132, sq. J. H. Voight. Versuch einer neuen Theorie des Fevers, p.  157,
sq.
  • W. Basche, on the Morbid Effects of Carbonic Acid Gaz, on Healthy Ani*
mals, Philadel.  1794, 8vo. p. 46.
  ! Abernethy, 1. c.

  \ Fr. L. Andr. Koeler, De Odore per Cutem spiran - in statu sano ac mor-
boso, Gotting. 1794, 4to.
  § The balance employed by Sanctorius, to estimate the loss of perspired
matter, is described in his Comtn. in Primam Fen Primi L. Canon. Avicennx,
Venet. 1646,4to. p. 781.
  Another much more simple and better adapted for the purpose, is describ-
ed by Jo. Andr. Segner, de Libra, qua aui quisque  corporis pondus explorare
posset, Gotting. 1740, 4to. J. A. Klindworth, an  excellent Gottingen  instru-
ment-maker, at my instigation, altered this, and rendered it more convenient
and accurate.
                                Q 
U4            ©F THE  CUTANEOUS PERSIURATION.

                          NOTES.
   (A)  The functions of the skin are but imperfectly known.
Besides forming a  watery secretion (193,  sq.)*  and  pro-
ducing  changes similar  to  those  which  occur in the lungs
(1JM),! it is believed by some to be an  organ of a! sorption,
while others deny that  absorption ever  takes  place  unless
friction  is  employed, or the cuticle abraded.   Dr.  Currie's
patient  labouring under  dysphagia seated in the cesphagus,
always  found his thirst relieved  by  bathing, but never ac-
quired  the least additional weight.!    Dr. Gerard's diabetic
patient  weighed no more  after cold  or warm  bathing  than
previously •§  Seguin found no mercurial effects from bathing
a person in a mercurial solution, provided the cuticle remain-
ed entire ; they occurred, however,  when the cuticle was abra-'
ded.||
   But these  are  no  proofs  that  water  was not absorbed,
because the  persons  immersed   did  not  lose  in weight,
which  they  would have  done if not  immersed, owing to
  * Lavosier and Seguin (Memoires de I'Academie des Sciences, 1790, p. 610)
enclosed the body in a silk bag varnished with elastic  gum, having a small
opening carefully cemented around the mouth, so that by weighing the body
previously and subsequently to the experiment, they were  able to ascertain
exactly what had been lost by vapour, and by subtracting from this loss the
weight of the perspired contents of the bag, they also ascertained how much
of this had passed off" by the lungs.   From  repeated  trials they found the
mean pulmonary discharge in twenty-lour hours amounted to 15 oz. and the
cutaneous to 1 lb. 14 oz.  The quantity of carbon separated by the lungs
Ought however to have been taken into the acconnt.  If it amounts to 11 oz.
in twenty-four, which I cannot believe it does, there will be but 4 oz. of pul-
monary exhalation.
  ! Cruikshanks on Insensible Perspiration, and Ellis's Further inquiry on the
Changes produced in Atmospheric Air, &c.
  \ Medical Reports, &c.       § Rollo, On Diabetes.
  | La Medicine' eclairee, &c. T. 3. 
              OF THE  CUTANEOUS PERSPIRATION.           Ho

the pulmonary and cutaneous exhalation; this therefore must
have been counterbalanced by absorption somewhere, and no
shad- >w of proof can be urged  against its occurrence by the
skin, as  Dr. Kellie remarks in his excellent paper on  the
functions of the skin.*  Seguin too found two grains of the
mercurial salt disappear in  an  hour from the solution when
of the temperature of 18° Reaumur.
  There is evrry reason to believe  the occurrence of cuta-
neous absorption independently  of friction or abrasion of the
cuticle.   First, the existence of absorbents all over the sur-
face cannot be intended for use merely when friction is em-
ployed or the cuticle abraded.  Secondly, we have many facts
which prove absorption without these  circumstance:,  either
by the skin  or  lungs or both, uhile  no reason can  be given
why they should  be attribuvu solely to the  lungs.  A boy
at Newmarket who had been gc ■■>•[} reduced before a race,
was  found  to have gained  m) \>%. in weight  during an hour,
in which time he had half a glass only of wine.!  Dr. Home
after being fatigued and going  to bed  supperless,  gained 2
oz. in weight  before seven in the morning.!   ^n three dia-
betic  patients of Dr. Bardsley's, the amount  of the  urine ex-
ceeded that  of the  ingesta,  and  the  body even increased in
weight, and  in one of the instances as much as 17 lbs-!   Dr.
Currie allows that in his patient, *« The egesta exceeded the
ingesta in a  proportion  much greater than  the waste of his
body  will explain."  Similar facts are recorded by De Haen,
Haller, &c.  The same patients  urine too after the  daily use
©f the bath, flowed more  abundantly and became less pungent.
* Edinburgh Med. ana Surg. Journal, vol. i.
! Witson's Chemica Essays iii. 101.
i Medical Facts and Expenments. 
116
OF THE FUNCTIONS OF THE NERVOUS SYSTEM
                      SECT.  XII.


     OF THE FUNCTIONS OF THE NERVOUS SYSTEM IN GENERAL.

   197. We now come to the other class of functions termed
animal, (83 II.) by which the body and mind are connected.
They have obtained their name  from existing in animal sys-
tems only, and from enjoying a greater  range of operation
than those properlv denominated vital.
   198. The principal organs of these functions are the brain,
medulla  spinalis,  and  the nerves, the  greater part of which
originate from these sources.*   They may be properly re-
ferred to  two classes, sensorial and  nervous : the former
comprehending all excepting the nerves and their immediate
origin,—all that serves more  directly as the connection be-
tween  the office of the nerves  and the  faculties of the mind.
   199. Upon  this division  rests  the  beautiful  observation
of the illustrious Sommerring,!  respecting the  correspon-
dence  between the relative  size of each  class with  the  fa-
culties of  the mind,—That  the smaller  the nerves  are,
  * Eustachii, tab. xviii. fig. 2.
  ! Diss, debasi eucephali. Gotting. 1778, 4to. p. 17. Also his work, already
quoted, upon the anatomy «.»f the negro, 59, sq.
  JGotter. Ebel's  Observationes neurologicee ex anatome comparata.  Traj
ad.Viadr. 1788, 8vo. 
          OF THE FUNCTIONS OF THE NERVOUS  SYSTEM.      117

compared with  the  sensorial  class, the greater  is the deve-
lopement of the mental faculties.   In this  sense,  man  has
the  largest brain  of all  animated beings,—if  its  bulk  be
compared with  that of the nerves arising from  it;  but by
no means, if its weight be  compared with that of the whole
body.
  200. Besides the bony cranium, a threefold covering is af-
forded to the brain,* viz. the dura and pia  mater,  and  be-
tween these two, the tunica arachnoidea.
  201. The  dura mater,\ which lines the inside of the cra-
nium, like a periosteum, forms various  processes.   By the
falx it divides  the  hemispheres of the cerebrum and  cere-
bellum ;  by the tentorium! it supports  the posterior lobes of
the cerebrum, and prevents their pressure  upon the subjacent
cerebellum.
  In  its  various duplicatures  it  contains and supports the
venous sinuses,^ and   prevents their  pressure.   These  re-
  * Eustachii, tab. xvii. xviii.
  HaUeri Icones anat. fasc. vi. tab. i. ii. iii.
  Santorini, tab. posth. ii. iii.
  ! J. Ladmiral's  Icones  durx matris in concava et convexa superfcie visa.
Amst. 1738, fasc. i. ii. 4to.
  if In the skulls of some mammalia, a remarkable  lamina of bone  pe-
netrates a duplicature of the tentorium, and supports it.  Cheselden (Anat.
of the bones, c. 8.) supposes this bony tentorium to exist in fcrcc only; but
it is found in the equine  genus, the cercopithecus paniscus, the delphinus
phococna, &c.  Its use is uncertain :  that which is generally ascribed to it
(for instance, by Laur. Nihell de cerebro.  Edinb. 1780, p. 4) of supporting
the cerebellum  in those mammalia which leap considerably, is improbable,
because we find it in animals also of slaw motion, as the bear, and not in the
ibex,  whic'u moves with the greatest velocity.
  § Vieussen's Neurograph, universal, tab. xvii. fig.  1
  fjuverney's CEuvres anatom. vol. i. tab. iv. 
 118     OF THE FUNCTION'S  OF THE NERVOUS SYSTEM.

 ceive  the  blood returning from the  brain  to the  heart, the
 proportion of  which to  the  rest  of the blood, Zinn  long
 ago very truly  remarked, has  been  over-rated by  physio-
 logists.
   202. Next to the dura  mater lies the arachnoid, so named
 from its thinness.   Its use is not exactly known ; it is desti-
 tute of blood-vessels (5), and extended like the dura mater
 merely over the substance of the brain, without  following the
 course of its furrows and  prominences. (A)
   203. On the  contrary, the membrane called pia mater by
 the  ancients, closely follows the  cortical substance  of the
 brain,*  and possesses  innumerable  blood-vessels,  which
 penetrate into the latter.   Hence,  if a portion  of this mem-
 brane  is detached, we find the external surface very smooth,
 while  the  internal is villous,  and  resembles  the roots of
 moss.-j-
   204. The cerebrum  and cerebellum are composed of vari-
 ous  parts, differing in texture and figure,  but unknown  in
their uses.   The  most remarkable  are  the four ventricles,!
in the  two anterior and  fourth of which is found the  cho-
roid plexus, of whose function we are  ignorant.^
  TIaller's icones anat. fasc. i. tab. vi.
  Walter De morbis peritonai et apoplexia.  Berol. 1785, 4to. tab. iii. iv.
  Vicq. d'Azyr's Planches Anatomiques. xxxii. et xxxv.
  * Kuyschii Respons. ad ep. problemat. nonam.  Amst. 1670, tab. x.
  ! B. S. Albini Annot. acad. L. 1. tab. ii. fig. 1. 5.
  t S. Th.  Sbmmerring 'uber das  Organ der  Seek.  Region. 1796,  4to.
tab. i. ii.
  § The  importance of this plexus is shewn in the dissection of maniacs, in
■whom it alone is very frequently found diseased. 
         OF THE functions of the NERVOUS SYSTEM.       119

   205. The substance of the brain is twofold : the one called
cineritous or cortical, though not always situated exteriorly;
the other white  or  medullary.   Between the two, Sommer-
ring*  has  detected  a third  substance, most conspicuous in
the arbor vita? of the cerebellum, and  the posterior  lobes of
the cerebrum.
   206. The proportion of the cineritousf to the cortical sub-
stance, decreases as  age  advances ; being greater in children,
less in adults.    It is almost wholly composed of very  fine
vessels,  both  sanguiferous!  and  colourless,  (92)  of  which
some few penetrate  into the medullary substance :§ the latter
is composed, in addition to these vessels and a  fine cellular
substance, of  a pultaceous  parenchyma, which, if examined
with glasses, exhibits no regular structure,!) and, upon chemi-
cal analysis, affords  a  peculiar matter,  in some measure re-
sembling albumen.
   207- The brain,  after  birth, undergoes  a constant  and
gentle motion,**  correspondent  with  respiration;  so  that
  * De baai encephali, p. 13.
  Compare Gennari De peculiari structura cerebri  Parma:, 1782, 8vo. tab.
ii. iii.
  ! Malpighi De cerebri cortice c. rel. de vueerum structura Exercit, Lond.
1699, 12mo.
  Ruysch De  cerebri corticali substantia ep. problemat. xii.  Amst. 1699.
4to.
  Chr. Frid. L'idwig. De cinerea cerebri substantia.  Lips. 1799, 4to.
  $ Sommerring De hubitu vasorum cerebri in  Denkschrifen der Acad, der
Wiss. zu Miinclten. 1808, tab. i.
  § B. S. Albini Annat. Acad. L- 1. tab. ii. fig.  4. 5.
  || Consult Metzger's Animadversiones ad doctnnam nervorum.  Regiomont
1783, 4to.
  •* T.  Dan Schlichting first  accurately described this phenomenon in the
Commerc. litter. Noric. 1744, p.  409, sq. and more largely in the Mem. pre-
sentes d /'.lead, des Sc. de Paris, T. 1. p. 113 
 i20      OF THE FUNCTIONS  O" THE NERVOUS SYSTEM.

when the lungs shrink in expiration, the brain rises a  little,
but when the chest expands, it again subsides.*
   208.  The  spinal  marrow  is  continuous  with the brain,!
and may  be said either to spring from the  brain, as from  a
root,  or,  on the  contrary, to  terminate  in  it, and  grow
into  its substance.|    Contained   in  the flexible  canal of
the  vertebrse,  it is enveloped  by the  same  membranes as
  Haller discovered the  cause of it by numerous dissections of living ani-
mals.   See his pupil, J.  Dit. Wolston's  Exfierimenta circa motum cerebri*
cerebelli, &c. Gotting. 1753.
  Consult also after F. de la Mure, Larry's  Dissertations on the same point
in the Mem. Presenters, T. iii. p. 277,  sq. 344, sq.  Also Portal on a similar
motion, observable in the spinal  marrow.  Mem. de la  Nature de plusiers
Maladies.  T. ii. p. 81.
  * I once enjoyed an opportunity of very distinctly observing this motion
and making some  experiments with respect to it,  in a young man eighteen
years of age.   When not five years old, he had fallen from an eminence and
fractured the frontal bone on the left side  of the coronal suture : since which
time, there had been an immense  hiatus, covered by merely  a soft cicatrix
and the common integuments.   The'hiatus formed a hollow, deeper  during
sleep, and varying according to the state of  respiration :  very deep if he re-
tained his breath, much more shallow, and even converted into a swelling,
by a long continued expiration.   At the bottom of the hollow, I observed  a
pulsation synchronous with the pulsation  of the arterial 6ystem, such as
deceived Petriolus, Vandellus and other adversaries of Haller, confounding
it with that which  depends upon respiration.—1 may add, that this wound on
the left side of the head, had rendered the right arm and leg paralytic.
  ! J. J. Huber De medulla spinali.   Gotting. 1741, 4to.  The plate  is to
be found among Haller's fiiscic. i. tab. ii.
  Haller's own plates of  the same part are  in the same  fasciculus, vii. tab.
iv. v.
  Monro (filius)   On the Nervous System, tab. x. fig. 1.
  $ Consult  the Anatomie et Physiologie du systeme Nerveux,  &c. par F. J.
Gall et G. Spurzheim.  T. 1.  Paris, 1810, 4to. 
          OF  THE  FUNCTIONS  OF THE NERVOUS  SYSTEM.      121

the brain : its substance  was also twofold, but the medullary
is exterior to the  cineritious.
   209-  From these two sources,—the brain and spinal mar-
row, arises the greater part  of those chords, which are more
or  less  white and soft, chiefly composed of cellular canals
containing nervous medulla,*  and  distributed  throughout
nearly all the the soft  parts , some nerves,\ however, may be
more properly considered as uniting with the brain and spinal
marrow, than springing from them.
   210.  After the numerous  experiments!  made  by  Hal-
ler  and  other  very   careful   observers,  we  axe certain,
from  minute  anatomical  examination,  that  many of  the
similar  parts  do not  exhibit any  true vestige of  nerves j
and from  surgical observations,^ and dissections  of living
   *  Reil De Structura Nervorum, Hal. 1796, fol.
   Osiander in the Comm. Soc. Reg. sc.  Gotting. T. xvi.
   !  Rob. Martin's oration De Proprietatibus Nervonim  Generalioribus, pre-
fixed to his Instil. Neuroligicx.
   %  Haller on the sensible parts of the body in the Comment.  Soc. sc. Got-
ting. T. i-  and  his discourse upon them in the  Nov.  Comment. Gotting.
T. iii.
   Petre Castell's Experim, quibus constitit varias h. c. partes sentiendi facul-
tate  carere.  Gotting. 1753, 4to.  And three entire collections on the con-
troversies excited by the Gottingen publications  throughout Europe.
   SulP insensibilitate irritabihta,  dissertazioni transportate  da J. G. V. Petrini.
Rom. 1755, 4to.
   Sulla insensitiva ed  irritabihta Halleriana  opuscoli raccolti da G. B.  Fabri.
Bonon. 1757—59, iv. vol. 4to.  And that which Haller himself  published
under the title of Mtmoircs sur la Nature sensible et irritable des Parties du
corps humain.  Lausanne, 1756—59. iv. vol.  l'2mo.
  § In  the great variety and even  contradiction of opinion, which, as
we shall presently  mention, exists in  respect to the feeling of tendons
and  other parts when  injured,  I have alwavs  considered negative argu-
                               K 
122       OF THE FUNCTIONS OF  THE  NERVOUS SYSTEM.

animals,*  that, they  do  not evince  the least  sign of  feel-
ing.
   Such are  the cellular  substance,  the epidermis, and reti-
culum  mucosum, the hairs and nails.
   The cartilages,  bones, periosteum, and marrow.
   The tendons, aponeuroses, and ligaments.
   Most extended  internal membranes, as the dura mater and
arachnoid,; the  pleura, mediastinum,  and pericardium ;  the
peritonaeum ;  also  the cornea, &c
   The greater part of the  absorbent  system,  especially the
thoracic suet.
   Lastly, the secundines and umbilical chord.  (B)
 ments of more weight than positive, because nothing is  more fallacious
 than the ideas of patients as to  the seat of internal  pains.   To say  nothing
 of cases where amputated parts appear to  the patient as still in possession
 of fl-eling, it is well known that some have felt a fixed pain for a great length
 of time, in  parts where  after  death  nothing uncommon  was observable -t
 and that, on the other hand,  in chronic  diseases, pain is sometimes not
 felt in the diseased  part, but'in another  which  is healthy and  perhaps
 very remote.
   We may in  this way much more easily explain syphilitic pains, for in-
 stance, referred to the bones, than so  many contradictory  experiments, in
 which I have seen the medulla roughly  handled without causing the least
 uneasiness.
   * 1 am every day more convinced that much caution and   practice
 and repetition of the same experiment, in many different kinds  of  ani-
 mals,  are necessary  in  establishing  the  laws or'  physiology  from   dis-
 sections of  living animals.   To  adduce  the  example of the supposed
 feeling of the medulla, I have  found different  results  in many mam-
 malia  and birds.   Many allowed the medulla to  be  destroyed  without
 evincing any symptom of pain ; others  were convulsed,  and cried  out
 on the approach of  the instrument.  The latter might be agitated from
 the dread of fresh torment, on  seeing the  knife ;  and  the  former, h. ving
 suffered great torture, might have been insensible to the less violent irri-
tation  of the medulla, although it were endowed with nerves. 
          OF THE FUNCTIONS OF THE NERVOUS SYSTEM.       123

   211.  The  ultimate origin of most nerves  from the  brain
cannot be detected.   A question is agitated even at the pre-
sent day, whether the nerves of  each side arise from the cor-
responding or the opposite portion of the brain.*   The latter
opinion is countenanced by certain pathological phenomena,!
and the decussation of  fibres  in the medulla  oblongata! and
conjunction of the optic nerves.§ (C)
   212.  A  continuation of the  pia  mater follows  the me-
dulla  of the  nerves at their  commencement,!!  in  such  a
way,  as to unite very delicately with the vascular cortex.**
But  as soon  as  they have quitted  the brain  or  medulla
spinalis,  their  structure  becomes peculiar,  different  from
all the  other similar parts.  They  form  transverse  folds
more  or less oblique and angular,  long since described by
P.  P. Mollinelli,!!  who not  inaptly  compared  them  to
 . * Lassus has diligently collected the different opinions of writers on this
point.  Sur les deconvenes faites en Anatomic p. 299, sq.
  ! Compare Mein. Sim. De Pui De hotnine dexiro et sinistra. L. B.  1780,
8vo. p. 107, sq.
  % v. Gall and Spurzheim, and Osiandor. 11. cc.
  § Sbmmerring in the Hessischen Beytr'dgen zur Gelehrsamkeit,  P. i.  et iv.
  F.  N. Nothig. (prxs. Sbmmerring)  De  decussatione  nervorum  optic.
Mogunt. 1786,8vo.
  J. F. Acker maim in the Biblioth. Medica, which I published, vol. iii. p. 3P>7-
706.
  Hor. Caldani, Opuscula Anat. Patav. 1803, 4to. p. 111.
  J. and C. Wenzel.  Prodromus eines IVerkes uber das Him. p. 11.
  || Consult Pfeffinger De structura Nervorum.  Argent. 1782, 4to-
   *"* Wm. Battie De Principiis Animalibus.  p. 126.
  ■j-j-  Comment. Instituti Bonoinms. T. iii. 1755, p. 282, sq.fig. 1, 2.
  The observation of Mollinelli has been abundantly confirmed and further
illustrated  by Felix Fontana and Al. Monro: the latter in his work so  often
quoted, and the former in his treatise Surle V-enin dela Viperi.  Flor.  1781,
4to. vol. ii. 
.124     OF THE FUNCTIONS OF THE NERVOUS  SYSTEM.

 the rugae  of earth-worms, or  the rings of the  aspera ar-
 teria.
   213.  The nerves, especially  those which are remarkable,
 for instance, the intercostals and par vagum, are every where
 distinguished by ganglia, or nodules of a compact structure
 and reddish ash colour, but  with whose functions  we  are
 scarcely acquainted.   I  am most inclined  to believe with
 Zinn,* that they unite more intimately the nervous filaments
 which meet in them  from  various directions : so  that each
 fibre passing out,  is composed of a portion of  every fibre
 that has entered in.j-
   Nearly the same holds good  with respect to the plexuses,
 which are produced by the union  and  reticulated anastomo-
 ses  of different nerves, and by a  similar contexture of fila-
 ments into which the  nerves are split.
   214. The ganglia and  plexuses are most abundantly  be-
 stowed upon the spinal and intercostal or sympathetic nerve.
 The latter, united by a  few delicate filaments  only with the
 rest of the nervous system,  constitutes a  peculiar  system,
 chiefly belonging  to  the  involuntary  functions.   For  this
 reason,  Bichat, viewing it as  presiding over organic life,
 distinguished it from the  other nerves belonging  to animal
 life, to use his own language.!
  * Mtm. de I'Acad, des Sc. de Berlin.  Vol. ix. 1753.
  ! Consult among others who treat professedly of the ganglia, J. Johnstone
in the Med Essays and Observ.  Evesham, 1795, 8vo.
  J. Gottl. Haase's Dissertation.  Leips. 1772, 4to.
  T. Caverhill's Treatise on Ganglions.  Lond. 1772, 8vo.
  Ant. Scarpa's Anatom. Annotat. L. i. De nervor.  Gangliis et Plexubut.
Matin. 1722, 4to.
  G. Prochaska De structura nervorum.  Vindob. 1780, 8vo. Al. Monro. 1. c.
  i See Reil in the Archiv fur Physiologic  T. vii. p. 189. 
         ©F THE  FUNCTIONS OF THE  NERVOUS SYSTEM.      125

  215.  The terminations of the nerves are no less concealed
from  us than their origins.   Excepting a f.rw, whtch spread
out in the form of membranes, as the optic nerve, which be-
comes the  retina ;  the  portis  mollis  of  the sevtruh  p^ir,
which forms a zone in the spiral lamina of the cochlea; tie
ultimate filaments of the rest penetrating into the  viscera,
muscles, corium, &c. are so intimately blended with thi. sub-
stance of these parts as to elude  observation.
  216.  The parts just described, viz.  the sensorium and the
nerves originating in it and distributed  throughout the body,
constitute that system  which, during  life, is the bond of
union between the body and the mind.
  217.  That the mind is closely connected with the brain, as
the material condition of mental  phenomena, is demonsr;a^d;
to omit such arguments as the immediate connection between
the brain and the organs of sense, by  our consciousness and
by the  mental disturbances which ensue upon affections of
the brain.  (D)
  218.   The singular situation  and form before alluded to,
of certain   parts  of the  brain, and likewise some  patho-
logical  phenomena, have induced  physiologists   to suppose
certain  parts,  in particular,  the seat of the soul.  Some
have  fixed  upon the pineal gland,* others the corpus callow
  » The Cartesian hypothesis appeared to receive some weight from the
dissection of maniacs, in whom the pineal gland was found full of calca-
reous substances.  But more careful observation .hewed,  that, after the
twelfth year, it was generally filled with a pearly sa.id, in the healthiest
persons, though very seldom in  animals  Sbmmering de lafnllas vel prope
vel infra gland, pin. sitis, s. de acervido cerebri.  Mogunt.  1785. 8vo. 
126     OF THE FUNCTIONS OF THE NERVOUS SYSTEM.

sum,* the pons varolii, the medulla oblongata, the  corpora
striata, and the water of the ventricles, which washes against
the origin of some nerves.  Others not contented with one
spot, have assigned particular parts of the brain for individual
faculties and propensities.  (E.)
  219.  The energy of the whole nervous  system does not
depend  solely upon the brain.   The spinal marrow, and
even the nerves, are possessed  of their  own powers, which
are sufficient to produce contractions in the muscles.  These
powers  are  probably supported  by the vascular cortex  of
these parts, (212).   In man, the powers proper to the nerves
are less, and those depending upon the brain greater, than in
animals, especially the coldblooded. J
  4220.  The office  of the whole nervous  system is twofold.
To excite motion in other parts, especially in the voluntary
muscles, of  which we shall hereafter speak at large;  and to
convey impressions made upon the organs of sense  to  the
brain, and there to excite  perception ; or by means of sympa-
thies (56), to give occasion to reaction.
  221.  Experiment  and  observation put these functions of
the nervous  system beyond the reach of controversy.  To un-
fold the nature of these functions is difficult indeed. (F.)
  222.  Mcst opinions on this  subject  may be divided into
two classes.   The one  class regards the action of the ner-
vous  system  as  consisting in an oscillatory motion.  The
other ascribes it to the motion of a  certain fluid, whose
nature is  a  matter  of  dispute;  by some called animal spi-
  *  The prerogative of this part was ably refuted by Zinn.  Exp. circa
corpus callosum, cerebellum, duram  meningetn,  in vivis animalibus instit.
Gott. 1749. 4to. 
          OK THE  FUNCTIONS OF THE  NERVOUS SYSTEM.      127

 rits,* and  supposed to run in vessels;  by others a matter
 analogous to fire, to light,  a peculiar ether, oxygen, electri-
 city, or magnetism.
   223.   Although  I  would by no means assent to either of
 these opinions,  I  may be, allowed  to  observe, that  most
 arguments  brought  by one  party against the hypothesis  of
 the other, must necessarily be rude in proportion to the sub-
 tlety of the  oscillations (if such exist)  of the nerves or  the
 nervous fluid.
   224.  These two  hypotheses may,  perhaps, be united, by
 supposing a  nervous fluid thrown into oscillatory vibrations
 by the action of stimulants.
   225.  The analogy between the structure of the brain and
 some  secreting organs,  favours the belief of the existence
 of  a nervous fluid.   But  tubes and canals are evidently no
 more requisite  for its  conveyance, than  they are  requisite
 in  bibulous  paper  or any other matter  employed for  fil-
 tering.
   The opinion receives much weight  from the resemblance
 of the action of the  nerves to the phenomena produced  by
 the series of a  galvanic apparatus and by the  common  elec-
trical machine,!" in a living animal, or in parts not quite de-
prived of vitality.  These  phenomena in fact long ago indu-
ced some physiologists to compare the nervous to  the  Elec-
tric  fluid.  The  singular and undeniable effects  attributed
  * See Michelitz's Scrutinium Hypotheseos  Spirituum Animalium.  Prag.
1782, 8vo.
  ! Fr. Al. Von Humboldt uber die gereizte Muskel itnd Nerven fafer. Posen.
1797, ii. vol. 8vo.
  J. W, Ritter, Bevieis dass ein besiiindiger Galvanismus den Lebensprocess im
Thierreiche begleite.  Vinar. 1798, 8vo. 
 128     OF* THE FUNCTIONS OF THE NERVOUS SYSTEM.

 to animal magnetism,*  as  well as  other phenomena  which
 have given rise to the belief of a kind of sentient atmosphere
 surrounding the nerves,t  agree very well with  the same hy-
 pothesis.
   226.  If we regard the  oscillation  of the nerves, not as
 similar to  that which occurs in  tense chords,  but of such a
 description as may be conceived to occur in the soft pulp of.
 the brain, we shall find many physiological phenomena exactly
 corresponding with the supposition.
   It is  demonstrated  that  hearing depends upon an  oscil-
 lation.
   In vision  also  it probably occurs, although not to the ex-
 tent imagined by Euler.
   The  penetration of Hartley  !  in following  up the  con-
jectures of the Great Newton,§ has  rendered it so probable,
 that the action of the other senses is  not very dissimilar from
 this oscillatory  motion,  that on the  same  supposition  he
 very ingeniously  explains,  principally   by  means  of the
vapour   of the   ventricles   (called  by him   the  denser
 ether) II  first, the association  of  ideas,  and again by the
 assistance of this, most of the functions of the animal facul-
 ties.  (G)
  * J. Heineken, Ideen v. Beobachtungen den thierischen Magnetismus betres-
send.  Brem. 1800. 8vo.
  ! v. Humboldt and Heineken. 11. cc.
  i Dav. Hartley's Observat. on Man, his Frame, his Duty, and his Expecta-
tions. Lond. 1749, 8vo. vol. i. p. 44.
  § Queries at the end of his Optics, Qu. 23, p. 355, Lond. 1789, 8vo-
  H Er. Darwin has carried these opinions of Hartley still farther. Zoono-
mia, T. i. 
        OF THE FUNCTIONS OF  THE NERVOUS  SYSTEM        129

                          NOTES.

   (a) The Pia Mater and Tunica Arachncides were consider-
ed as the same, till the Anatomical  Society of Amsterdam
confirmed, in  1665, the doubts  which were arising on  the
subject, and  Van  Home  demonstrated both membranes dis-
tinctly to his pupils.  The Dura Mater corresponds with the
fibrous  membranes, the Pia Mater with the cellular, and the
Tunica Arachnoides with the serous.   The latter is, in  na-
ture, office,  and  diseases,  exactly like  the serous; a  close
sac,  affording  as  the peritonaeum does to the  abdominal
viscera,  a double covering to the  brain  and spinal  mar-
row  and the  nerves before  their departure through  the
foramina of the Dura Mater, and lining the ventricles; in-
sulating the organs on which it lies, and affording them  great
facility of movement,  and liable to all the  morbid affections
of serous membranes.*
   (B) Although no nerves can be discovered in these parts,
and although in common they have no feeling, yet  that they
have in a lower degree, what  in a higher is called feeling, is
shewn by the extreme sensibility which they  acquire when in-
flamed, as they nearly all frequently are.
   (C) Gall and Spurzheim have  shewn that the nerves and
spinal marrow do not arise from the brain, but only communi-
cate with it:  for where the brain is absent, the acephalous foe-
tus equally possesses them, and neither the cerebral nerves
nor the  spinal marrow are in proportion to each other, in the
various species  of  the animal kingdom, nor  the spinal nerves
to the spinal  marrow.
•
• Bichat Traite des Membranes.
           S 
130        OF THE FUNCTIONS OF THE NERVOUS SYSTEM.

  They have also shewn that besides the numerous commu-
nications of the whole nervous system, the two sides of the
cerebrum, cerebellum, and spinal marrow, are united by com-
missures, and that the fibres of the  anterior pyramidal emi-
nences decussate each other, forming an exception to the rule
observed in  every other part of the brain, of the nervous fi-
bres destined to each side of the body,  running on the same
side of the brain; and  they hence  explain  why  injuries of
one side of the brain sometimes  influence the same, some-
times the opposite side of the body.  It  is to be hoped,  that
morbid dissection will ascertain the correctness of their expla-
nation.*
  (D) See Sect. vi. Note A, near the end, and Sect. 44, Note
E,  near the beginning.
  (E) Gall and Spurzheim maintain, that the fore  part of the
brain is subservient to intellect, the middle to sentiments, and
the back part to propensities, and point out particular spots in
each of their divisions for particular faculties, &c. and assert
that the size of each  spot, and of  the corresponding part of
the cranium, shew the strength of the faculty.  I refer the En-
glish reader to Dr. Spurzheim's well known work  for full in-
formation.
  It must be allowed, that their enumeration of faculties and
organs may and probably is very imperfect and incorrect, that
infinitely more remains to be done, that many of Dr. Spurz-
heim's  illustrations are  objectionable, not to say  ridiculous,
and that his  English work is a very hasty performance.
  (F)  While the brain  is evidently  the   organ of mind,
the nerves  united  with it, and the spinal marrow, together
with its, nerves, are as evidently the instruments by which
  * Anatomic et Physiologic du Systeme nerveux, par Gall et Spurzheim, and
Physiognomical System by Spurz!ie;in.                            x 
         OF THE FUNCTIONS  OF  THE NERVOUS SYSTEM.      131

it affects, and is affected by the other parts of the body, to
which'these nerves are  distributed.  By their  instrumentali-
ty,  the  brain  contracts the voluntary muscles,  influences the
functions of every part when under the operation of the dif-
ferent passions, and receives  impressions made upon the
body.   The consequences of divisions of the  nerves or spi-
nal marrow, fully  substantiate  these points.
  In brainless foetuses, the circulation, secretion, &c. proceed
equally as in  others which, besides spinal marrow, nerves
and ganglia, possess a brain.   Vegetables absorb, assimilate,
circulate, secrete, and in many instances  contract on the ap-
plication of stimuli, and yet are not known to possess nerves.
Muscles after the  division of the nerves which connect  them
with the brain, contract  equally as before, when  irritated.
In  animals liable to torpor, the season of  torpidity  produces
its  effects  equally upon  those  muscles  whose nerves  have
been divided, or when the brain, &c. is destroyed.
  After the removal or  destruction of the brain and  spinal
marrow in  animals, the heart  still  continues to  act  and
the blood  to circulate,  provided respiration  is artificially
supported.*   But  the  involuntary   functions  are  closely
connected  with  the   brain  and spinal   marrow,   for  the
sudden  destruction  of these  parts or a   certain portion of
them, puts a stop  to  the circulation ;t  the  application of
stimuli to  them  excites  the  action  of .the  heart and  even
of  the capillaries  after its removal ?!  to  say  nothing of the
  • Experiments, &c. by A. P. Wilson Philip, M. D. and Wm. Clift, Philos.
Trans. 1815.
  ! Le Gallois, Sur le Principe de la Vie, and Wilson Philip, 1. c
  \ Wilson Philip, 1. c.  Probably by excessive stimulus, as the voluntary
muscles are afterwards insensible to stimuli, although alter a mere division
of their nerves, they retain their excitability. 
 132     oi-' THE FUNCTIONS OF THE NERVOUS SYSTEM.

 influence of the passions upon them.   Nay more, the invo-
 luntary functions seem as dependent upon the brain and spi-
 nal marrow, as they probably  are upon the ganglia and gangli-
 ac nerves, for the division of the par vagum, or the destruc-
 tion of that  part  of the brain  with  which  it is connected,
 heavily impairs  the functions of the  lungs and of the sto-
 mach j*  and although the division of the spinal marrow,  or
 its  nerves, prevents voluntary power over the corresponding
 muscles, without  suspending the circulation, &c. in them,
 yet  this, and  what  are dependant upon it,—nutrition and
 animal heat, are evidently impaired more,  I think, than can
 be accounted for by the mere deficiency of muscular action.
  (G) These oscillations are  purely hypothetical and indeed
 improbable; were their existence proved,  we should know
 nothing more of the  real nature of the cerebral functions, for
 we should have to learn what were the peculiar properties of
 the nervous system, which enabled it alone of all substances
 to produce, when oscillating,  the  phenomena which it exhi-
 bits.  We  might as well attempt to explain the phenomena
 of motion,  chemical affinity  and  galvanism  by vitality and
 mind, as the phenomena of  vitality and mind  by mechanics',
 chemical affinity or galvanism.  They are altogether distinct
 principles, although there can be no question, that the  laws
 of mechanics,  chemical affinity  and  galvanism,  are  im-
portant and indispensable in every living system, in  sub-
 servience to life and mind.   The mind, for ought we know
 may stimulate  the voluntary muscles  by  means  of galva-
 nism communicated along the nerves, but then the galvanism
is not mind,  it is merely an instrument employed by the
mind.
* Le Gallois, 1. c. 
OF THE EXTERNAL  SENSES.
133
                      SECT. XIII.

     OF THE EXTERNAL  SENSES IN  GENERAL, AND OF
                  TOUCH IN PARTICULAR.

  227.  " e find  the other function of the nerves to consist
in communicating to the  sensorium the impressions made by
external objects.   This  is  accomplished by  the external
senses, which are, as it were, the watchmen of the body, and
the informers of the mind.
  The latter alone belong to our present subject.  For to re-
gard, with  Gorter, the stimulus which inclines us to relieve
the  intestines, the  sensation  of hunger, and other internal
calls of nature,  as  so many distinct senses, is  unnecessary
minuteness, as Haller long since observed.*
  228.  Touch merits our first attention, because it is the first
to manifest itself;  its organ is  most extensively spread over
the whole surface,  and it is affected by  most properties of
external objects.
  2S9.  For we perceive not  only some  qualities, as  heat,
hardness,  weight, &c. by the touch alone ;  but our knowledge
obtained by other senses, respecting some qualities, is render-
ed more accurate by  the touch;  such qualities  are  figure,
distance,  Sec.
  230.  It is less falacious than the other senses, and by cul-
ture capable  of such perfection, as to supply the defects of
the others, particularly of vision-!
* J. De Gorter's Exercitationes Medica, iv. Amst. 1737, 4to.
! Consult Rol. Martin in the Schwed Abhandl. Vol. xxxix. 1777-
G. Bew in the Memoirs of a Society of Manchester, Vol. i. p. 159.
Ch. Hutton'9 Mathematical Dictionary, Vol. i. p. 214. 
134
OF TOUCH.
   231.  The skin, whose structure we formerly  examined, is
 the general  organ  of touch.*   The  immediate seat is the
 papillae  of the corium, of various forms in  different  parts,
 commonly resembling warts,f in some  places fungous,!  in
 others  filamentous.§    The extremities of all the cutaneous
 nerves  terminate in  these  under  the  form of pulpy pe-
 nicilli.
   232.  The hands are the  principal seat of touch, properly
 so called, and regarded as the sense which examines solidity.
 The skin of the hands has many peculiarities.   In the palms
and on  each, side of the joints of the fingers, it is furrowed
and free from hairs, to  facilitate  the  closing of the  hand.
The extremities of both fingers and  toes  are furrowed  inter-
nally  by very beautiful lines  more or less spiral ;||  and  are
shielded externally by nails.
  233.  These  scutiform nails% are  bestowed  upon  man
only  and  a   few other genera  of  mammalia (I allude  to
the quadrumana which excel in the  sense of touch,)**  for
  * F. de Riet, De Organo Tactus, L. B. 1743, 4to. reprinted in Haller's An-
atomical Collection, T. iv.
  ! Dav. Corn, de Courcelles' Icones Muscular. Capitis, Tab. i. f. 2, 3.
  i B. S. Albinus' Annotat. Academ. L. hi. tab. iv. fig, 1, 2.
  § Ruysch's Thesaur. Anat. iii. tab. iv. f. i. Thes. vii.tab. ii. fig. 5.
  B. S. Albinus, 1. c. L. vi. Tab. ii. fig. 3, 4.
  | Grew in the Philos. Trans, n. 159.
  If B. S. Albinus. Annotat. Acad. L. ii. tab. vii. f. 4. 5. 6.
  ** Namely simiae, papiones, cercopitheci and lemures the apices of whose
fingers in their four hands are very soft and marked, as in the human subject
with spiral lines.                                            ««jc».i,
  Physiologists have disputed whether the sense  of touch is bestowed on
any besides  man and the quadrumana.  In determining this controversy
we  must recodect  what  was formerly said (81) concerning the differ
ence of constitution according to the mode of living.  On one hand, I would 
OF THE EXTERNAL  SENSES, &C.
135
the purpose of resisting pressure, and thus assisting the action
of the fingers, while examining objects.
   They are of a horny nature, but on the whole very similar
to the epidermis.  For under them lies  the reticulum, which
in negroes is black ;*  and under  this is found the corium, ad-
hering firmly to the periosteum of the last phalanx.   These
constituent parts  of the nails are striated lengthwise.   The
posterior edge, which, in the hands,  is remarkable for a little
lunated appearance, is fixed in a  furrow of the skin; and the
nails are growing constantly from  this, so as  to be perfectly
renewed every six months.
grant to both parties, that the snowy hands of a delicate girl must enjoy a
much more exquisite sense of touch, than what I called the fingers of ani-
mals. But, on the other hand, I have frequently seen simiae and papiones pos-
sessing much softer'fingers, and using these fingers to explore surfaces
much more dexterously, than many barbarous nations and innumerable per-
sons among the .ower orders of Europeans, whose hands have become har-
dened from labour.
  * B. S. Albinus De Habitu et Colore ASthiopum, fig.  3." 
136
OF TASTE.
                      SECT. XIV.


                        OF TASTE.
                                  «

   234. We perceive tastes  by the tongue and  in some de-
gree by the other neighbouring internal cutaneous parts  of
the mouth; especially by the soft palate, the fauces, the inte-
rior, of the cheeks and lips :  by them, however, we taste on-
ly what is acrid and very bitter.*
   235. The chief organ of taste is the  tongue,] agile, obse-
queous, changeable  in form,  and from its remarkable fleshy
nature, not  unlike the heart.
   236. Its  integuments  resemble  the  skin.   They are an
epithelium,  performing  the office of cuticle;  the  reticulum
Malpighianum :! and a papillary membrane, but little differ-
ent from the corium.
   237". The  integuments of  the  tongue differ  from the
skin chiefly in  these respects;—In  the epithelium being
moistened not by the oily fluid of the skin, but  by a mucus
  * Grew's Anatomy of Plants, p. 284, sq.
  Petr. Luchtmans De Saporibus et Gustu. L. B. 1758. 4to. p. 58, sqq.
  J. Gottl. Leidenfrost De sensu qui in faucibus est, ob eo qui in lin lingua exer-
citur, diverso. Duisb. 1771, 4to.
  ! Sbmmering's Icones Organorum Humanorutu Gustus.  Francof. 1808, fol.
  * In dogs and sheep with variously  coloured skin, 1 have commonly found
the reticulum of the tongue and t'auce? also of various colours
1 
OF  TASTE.
137
which  proceeds from the foramen caecum of Meibomius,*
and the rest of the  glandular  expansion of Morgagni.!—
And secondly, in the conformation of the papillae, which are
commonly  divided into  petiolated, obtuse,  and  conical.!
The  first  are very few in number  and situated in a lunated
series at the root of the tongue; the others, of various mag-
nitudes, lie promiscuously  upon the  back  of  the tongue,
and chiefly upon its edges and apex, where the taste is most
acute.§
   238.  These papillae are furnished with extreme  filaments
of the  lingual branch of  the  fifth  pair ;|| and through them
we probably acquire the power of tasting.  The ninth pair**
and the branch of the eighth, which also supplies the tougue,!f
appear  intended rather for the various movements of this or-
gan, in manducation, deglutition, speaking, &c.
  239.  For the tongue to  taste properly, it must be  moist,
and the substance  to  be tasted must be liquid, holding salts
in solution-!! (A)  For if either  is  in a dry state, we may
perceive the presence of the  substances by the ommon sense
of touch, which the tongue  possesses in  great acuteness but
  • Consult Just Schrader's Observat. et Histor. from Harvey's book De
Generation Animalium, p* 186.
  ! Morgagni's Adversar. Anat. Prima. Tab. i.
  * Ruysch's Thesaur. Anat. 1. tab. iv. fig. 6.
  B. S. Albinus' Annotat. Acad. L.  i. tab. i. f. 6—11.
  § Consult Haller's excellent description of the tongue of a living man, in
the Diction. Encyclypedique.   Yverdon  edition.  Vol. xxii. p. 28.
  || J. F. Meckel De Quinto pare Nervorum Cerebri. Gotting. 1748. 4to. p.
97. fig. 1- n. 80.
  •* J. F. W. Meckel De Nono pare Nervorum Cerebri.  Gotting. 1777, 4to.
  !! See Haller's Icon. Anatom. fasc. ii. tab. 1. letter g.
  Monro on the Nervous  System.  Tab. xxiv.
  i± Bellini. Gustus Organum novisUme deprehensum.   Bonon. 1665. 12mo.
                             T 
138                   OF TASTE.
cannnot discover their sapid qualities.   When the tongue
tastes very acutely, the papilla? around its apex and  margins
are in some degree erected.                           3
                        NOTE.

  (A) Certainly  an infinite  number of  bodies  are sapid,
which contain no  kind of salt.  Some gases and metals are
sapid; they however may possibly be united with the fluids
of the mouth, before they produce an impression. 
OF  SMELL.                       I39
                        SECT. XV.


                          Or SMELL.


   240. While taste  and  smell are closely related by the
 proximity of their organs, they are not less so by the analo-
 gy of their stimuli, and  by some other circumstances.  For
 this reason, they have been generally named chemical or sub-
jective senses.
   By smell we perceive odorous effluvia, taken in by inspira-
 tion, and  principally  applied to that  part of Schneiderian*
 membrane, which invests both  sides  of the septum narium
 and the convexities of the turbinated bones.
   241.  Although the  same mucous membrane lines the nos-
trils! and their sinuses,! its nature  appears different in diffe-
rent parts.
  * Conr. Vict. Schneider De Osse Cribrifsrmi et Sensu ac  Organo  Odora-
tus.  Witteb. 1§55, 12mo.
  This classical work forms an epoch in physiological history, not only be-
cause it is the first accurate treatise on the function of smell, but because it
put an end to the visionary doctrine of the organ of smell being the emunc-
tory of the brain.
  ! Sbmmerring's Icones Organorum Hnmanorum Olfactus,  Francof. 1810,
ibl.
  $ Haller's Icones. Anat. fasc. iv. tab. ii.
  Duverney's Oeuvres Anatom.   Vol. i, tab. xiv.
  Santorini's Tab. Posthum, iv. 
140
OF SMELL.
   Near the exterior  openings it is more similar to the  skin,
and beset with sebaceous follicles,  from which  arise hairs,
known by the name of vibrissae.
   On the septum and the turbinated  bones it is fungous, and
abounds in mucous cryptse.
   In the frontal, sphenoidal, ethmoidal, and maxillary sinu-
ses, it is extremely  delicate,  and supplied with an  infinite
number of blood-vessels, which exhale an aqueous dew.
   242. It appears the principal, not to say  the sole use of the          J
sinuses,* to supply this watery fluid, which  is perhaps first
conveyed to the three meatus  of the nostrils, and afterwards
to the other parts of  the organ, preserving them in that con-
stant state of  moisture, which is indispensable to the perfec-
tion of smell.
   The  sinuses  are so placed, that, in  every position of the
head, moisture can pass from one or  other  of them  into  the
organ of smell.
   243.  The principal seat of smell,—the fungous portion of
the nasal membrane, besides numerous blood vessels, remark-         l
able for being more liable to spontaneous hemorrhage than  any         I
others in the  body,  is supplied by nerves, chiefly  the first          J
pair,! which  are distributed on both sides of the  septum  na-         J
rium,  and  also  by  two  branches  of the  fifth  pair.   The    •.     J
  * In my Prolus. de Sinibus Frontal.  Gotting. 1779. 4to.  I have brought
forward many arguments from osteogony, comparative anatomy, and patho-
logical phenomena, to prove that the-.e sinuses contribute indeed to the smell,
but v\< tit  or nothing to voice and languaguage, as was believed by many phy-
siologists.
  ! Mitzger. Nervontm Primi Paris Historia.   Argent. 1766,4to.  reprint-
ed in i.rr.difbn's Tlcsaurus.   Vol. iii.
Scarpa, Anatomic Annotat. L. ii. tab. i. ii. 
Or  SMELL.
141
former appear to be the seat of smell  :* the latter to  serve
for the common feeling of the part, which excites sneezing,
&c.
  244. The exireme filaments of the first pair do not termi-
nate in  papillae, like the nerves of touch and taste, but, as it
were, deliquesce into the spongy  and equal parenchyma of the
nasal  membrane.
   245.  The organ  of smell is small  and very  imperfect at
birth.   The sinuses scarcely exist.  Smell consequently takes
place but late,—as the interanl nostrils are gradually evolved,
and is more acute in proportion to their size and perfection.!
  • This is shewn by  pathological dissection and comparative anatomy.
Thus  in Loder's  Observ. Tumoris Scirrhosi in Basi Cranii Reperti.   Jen.
1779,  4to. is a case of anosmia, following h compression of the first pair by a
scirrhus.    We are taught, by comparative anatomy, that in the most saga-J
cious mammalia, v. c. elephants, bears, dogs, bisulcus ruminants, hedgehogs,
Sec. the horizontal plate of the cribriform bone is very large, and perforated
by an infinity of sr«all canals, each of which contains a filament of the olfac-
tory nerve.
  ! While animals of the most acute smell have the nasal organs most ex-
tensively evolved, precisely  the same holds  in regard to some barbarous na-
tions.   For instance, in the head of the  North American Indian, (a leader of
his nation, and executed at Philadelphia about fifty years since), which I
have given in the First Decade of my Collection of the Crania of different Na-
tions, illustrated by nine  plates, the internal nares are of an extraordinary size,
go that the  middle conchae, for  instance, are inflated into  'immense bulls •
and the sinuses, first described  by Santonin, which are contained in them  I
 never, >n any other instance, found so large.
  The nearest to these, in point  of magnitude,  are  the internal nures  of the
Ethiopians, from among whom I have seven beads no«« before me, very diffe-
rent from each other, but each possessing a nasal >rgan, much Lrger than we
find it described by Sbmmerring to be in that nation, uber die kb'rperl.   Vers-
chiedenh dos Negers, Crc. p. 22. 
142
OF SMELL.
   246. No external sense is so intimately connected with the
sensorium and internal senses, nor possesses such influence
over them, as the sense of smell.*
   No other is so liable to idiosyncrasies, nor so powerful in
exciting and  removing syncope.
   Nor is any other capable of receiving more delicate and de-
lightful impressions;  for which  reason, Rosseau very aptly
called smell,  the sense of imagination.]
   No sensations can be remembered in so lively a manner as
those which are recalled by peculiar odors*!
  These anatomical observations accord with the accounts given by most re-
spectable travellers concerning the wonderful acuteness of smell possessed
by these savages.
  Respecting the North American Indians, consult among others Urlsperger.
Nachr. von der Grossbritann. Colonie Salzburg. Emigranten in America. Vol.
i.p. 862.
  Respecting the Ethiopians, the Journal des Scavans, 1667, p. 60.
  * See Alibert on  the Medical power of Odors, in the Mem. de la Soc. Me-
dicate. T. i. p. 44.
  f Emile. T. i. p. 367.
  * Respecting the  power of smell over the disposition and the propensities,
consult Benj. Rush,  in the Medical Inquiries and Observations.  Vol. ii. p. 34: 
OF  HEARING.
143
                       SECT. XVI.

                       OF  HEARING.

   247. Sound, which is excited by the collision of elastic bo-
dies and propagated by the air, is perceived by the sense of
hearing,* and is first recieved by the conchiform cartilaginous
external ear,!  which  few of our countrymen have the power
of moving-!   By this it is collected ;  then conveyed into the
meatus auditorius, which  is anointed  by a bitter  cerumen ;<S
and strikes against the membrana tympani, which is placed ob-
liquely in  a circular  furrow of the temporal bone, and sepa-
rates the meatus from the  interanl  ear.
   248. Behind this membrane lies the middle portion of the
ear,—the cavity of the tympanum, whose fundus  is directed
upwards and inwards.
   It contains  threell ossicula auditus:  of which  the  exterior,
  * Sommerring.  Abildung des Menschlichen Hb'rorgans.  Francof. 1806,
fol.
  f B. S. Albinus. Annotat. Academ. L. vi. tab. iv.
  t J. Rhodius ad Scribon. Largum. p. 44, sq.
  J. Alb. Fabricius De Hominibus ortu non differentibus.  Opuscul. p. 441.
  Ch. Collignon's Miscellaneous Works. Camb. 1786,4to. p. 25, sq.
  § Consult J. Haygarth in the Med. Obs.  and Inquires, vol. iv. p. 198, sq.
  H The existence of a fourth bone (called Lenticular) commonly believed
from the time of Franc. Sylvius, I have disproved at length in my Osteology,
p, 155. et seq. edit.  2.  It is wanting  in the greater number of perfect ex-
amples from adults. 
144
OF  HEARING.
 or malleus, adheres by its manubrium to the membrana tym-
 pani, is generally united in the adult to  the circular furrow
 above-mentioned by  its spinous process  which is directed
 forwards,  and it lodges its round head  in the hody of the
 incus.
   The incus is united to the head of the stapes  by the  extre-
 mity of its long process which extends into the cavity of the
 tympanum.
   The stapes resting its base  upon  the fenestra ovalis, runs
towards the vestibule of the labyrinth,  into  which, sounds,
struck against  the membrana tympani, are propagated  by the
 intervention of these three little bones.
   249. The Eustachian tube* runs from  the  interior of the
fauces into the  cavity  of the tympanum:  and the  inferior
scala of the cochlea has the same  direction j  the  opening of
the latter, termed fenestra  rotunda,]  is closed by  a  peculiar
membrane.  The true and principal use of each is not  suffi-
ciently known-!
   250. In the deepest part of the petrous bone  is placed the
internal ear, consisting of three parts.
   First, of the vestibule,  placed  between  the other  two,
into  which  open not  only the  fenestra ovalis, but  the five
orifices of  the  semi-circular  canals  which  lie posteriorly,
  * Saunder's Anatomy of the human ear.  Lond. 1801, fol. vol. i. ii.
  ! Scarpa De Structura Fenestras Rotunda, &c. Mutin. 1772, 8vo.
  $ Comparative anatomy renders it most probable that the Eustachian tube
is subservient to the action of the membrana tympani  It is found in all red-
blooded animals which possess a membrana tympani; but is wanting in fishes
which are destisute of this membrane.  The different opinions respecting its
use may be found in Keil's Arc/uv. fur die Physiol. T. ii. p. 18. iii. p. 165.  iv.
p.  105. viii. p. 67. ix. p. 320. 
OF* HEARING.
J 45
and the superior scala of the cochlea, which is placed an-
teriorly.
   The  vestibule  and  semi-circular canals loosely  contain
very delicate membranous bags,  lately discovered  by the
celebrated Scarpa.  Two of these lie in the vestibule, and
three in the semicircular canals.*
   251.  They, as well as the cavity of the cochlea, con-
tain a very limpid  fluid, bearing the name  of Cotunni,
who shewed it to be absorbed by two canals,  by him de-
nominated  aqueducts,]  and  by   the  no  less  illustrious
Meckel, diverticula;] the one  arises from the vestibule,
the  other from the inferior  scala of the cochlea.
   252.   The portio mollis of  the seventh  pair, together
with the  portio dura,  (which  afterwards runs  along the
Fallopian aqueduct)^ having  entered the internal acoustic
opening, transmits its medullary  filaments into  the lower
and cribriform part of it.^j  These  filaments run to the
vestibule  and semicircular  canals,  but  especially to the
base of the  cochlea, where they form a medullary  zonula,
marked by beautiful plexiform  striae, which pass between
the two laminae of the  septum cochleae.**
   253.  The oscillatory tremor,  which we  formerly  fol-
lowed  as  far as the fenestra ovalis (248), is  propagated to
  • Scarpa's Disquisitiones Anatomica de Auditu et Olfactu.  Tab. iv. fig.
5, tab. vii. fig. 5.
  ! Cotunni Dc Aqueductibus auris Humana.  Neap. 1760, 4to.
  ]. Ph. Fr. Meckel De Labyrinthi auris Contentis.  Argen. 1777, 4to.
  § Fallopius' Observ. Anat. p. 27, sq. Venet. 1561, 8vo.
  fl Brendelii Analecta de Concha auris Humanx.  Gotting. 1747, 4to.
  The same, De Auditu in Apice Concha, ib. eod. 4to.
  •* Consult Zinn's Observ. Botan.  Gotting. 1753, 4to. p. 31, sq.
  Scarpa 1. c. tab. viii. fig. 1. 2.
                           TT 
146                    OF HEARING.
the vestibule, where, by means of the water of Cotunnius
(251), it  strikes the auditory nerves distributed among the
windings  of the labyrinth.
  254.  Besides the muscles of the  malleus and stapes,*
supposed  to be voluntary,!  the  chorda  tympani,!  which
is placed between   the  handle  of  the malleus and  the
longer leg  of  the incus, is believed to  moderate the force
of  sound  struck  against  the membrana  tympani, and
afterwards  to be propagated  along  the cavity of the tym-
panum.§
  • B. S. Albini Tabula Muscul. tab. xi. fig. 29.
  + Eustach. De Auditus Organ, p. 157.
  Caldani. Institut. Physiol. 245, sq.
  £ T. Fr. Meckel De Quintopare Nervorum Cerebri, fig. 1. x. 71.
  Leop. M. A. Caldani on the Office of the chorda tympani, in the Saggi
dell' Acad, di Padova, T. ii.
  § Cotunni. 1. c. §. lxxxviii. Marherr's Proalect. in Boerhaavii Inst. Vol.
iii. p. 343. 
OF SIGHT.                      147
                     SECT. XVII.


                        OF SIGHT.

   255.  The instruments  of vision,—the eyes,* are  two
moveable globes, fixed  to  the optic nerves, whose decus-
sation we  formerly noticed (211), as  it were to stalks, in
such a manner, that their  insertion is not exactly opposite
the centre  of the cornea and iris, but behind this imagi>
nary  axis, rather nearer to the nose.'
   256.  They consist of various coats, containing pellucid
humours  of different degrees of density, so placed,  that
the rays of light can pass from  the  transparent anterior
segment of the  bulb to  the opposite part of the fundus.
   257.  The  external coat is called sclerotic.  It is defi-
cient in the centre, and that part is filled up by the cornea,
which is transparent,  lamellated, more or  less  convex,
and  projects like the segment of a small globe  from one
of larger  size.f
   258.  The interior of the sclerotica  is lined by the cho-
rioid, which abounds in blood vessels, especially verticose
veins, and is  dyed  on each side by a black  pigment,  ad-
  • Sbmmerring.  Abbildungen des  Menschlichen Auges.   Francfort,
1801, fol.
  ! Ad. Jul. Rose De Murbis Cornea ex Fabrica ejus Declaratis.  Lips.
1767,4to.
  G. H. Gerson De Forma Cornea  Deque Singulari  lisus  Phxnomeno.
Gotting.  1810, 4to. 
148
OF  SIGHS-
hering however but loosely to  its-concave surface, in the
form of  mucus.*
   259.  The chorioid  contains  the  internal coat—the  re-
tina,]—a medullary expansion  of the optic  nerve, which
passes  through  the  sclerotica and  chorioid-!   Its struc-
ture  is very beautiful.§
   In the imaginary axis of the  eye,  between  the two  prin-
cipal branches of  the central  artery,^  it  rs perforated by
the  singular foramen  of  Sbmmerring,**  which  is   sur-
rounded by a yellow  edge.!!                 •
 /
  * C. Mundini in the Comm. Instit. Banoniens.  T. vii. p. 29, H. F. El-
saesser (prxs. G. C. Ch. Storr) De pigmento Oculi Nigro.  Tubing. 1800,
8vo.
  ! B S. Albinus.   Annotat. Academ. L. iii. p. 59.  sq. L. iv. p. 75, sq. L.
v. p. 66, sq.
  \ Walter De Venis Oculi, &c.   Berol.  1778, 4to. tab. 1. fig. 2. tab. ii.
fig:-2.
  § The extremely beautiful  blood-vessels of the retina were first dis-
covered by T. Mery to be visible  in a living cat plunged into water.
Mem. de I'Acad, des Sc. de Paris, avant 1699, T. x. p. 656; and 1704,
p. 265.
  The radiated surface of the retina in the hare is most beautifully dis-
played by Zinn, in an admirable plate.   Comm. Soc. Scient.  Gotting.
T. iv. a. 1754, tab. viii.fig. 3.
  By Fontana, in the rabbit.  Sur. le ve?iin de la  vipere, vol. ii.  tab. V.
fig. 12.
  % A plate accurately representing the courses of these branches will
be found in the Oeuvres de Mariotte. p. 527, fig. 1.
  ••  Sdmmerring  De Foramine centrali  limbo  luteo  cincto retina hu-
mens:  in the  Comment.  Soc. Reg. Scient.  Gottingens.   T.  xiii.  Ph.
Ph. Michaelis  in  the  Journal der  Erfindungen in der Natur und Arx-
neyMss, p. xv.
   !!  As I have discovered this central aperture  in the eye of no animal
 besides man, except the quadrumana,  the axes of whose  eyes are,  like 
OF SIGHT.
149
   260.  The  anterior edge of the chorioid is terminated
by a  cellular  belt,  called orbiculis  ciliaris,  by which it
adheres firmly to a corresponding groove  in the sclerotica;
and from which two  other membranes,  viz. the  iris and
ciliary processes, are expanded in a circular  form.
  (26l.  The iris, (whose  posterior surface is  lined  by a
brown pigment, and termed uvea) lies  anteriorly to  the
ciliary processes, is  flat,  and washed on  all sides by  the
aqueous  humour;  narrower towards  the nose,  broader
towards the  temples.   Its texture is dense and  cellular,
and contains  no vestige  of  muscular fibre.    We  must
regard it, with Zinn,* as a membrane sui  generis, and  not
as a propagation from the chorioid.   The anterior surface
is differently  coloured in different persons,  and, during
life, counterfeits a flocculent appearance.!
   262.  The blood-vessels of  the iris  run  chiefly  on its
anterior surface,  and  are  continued in  the foetus  into  the
membrana pupillaris,] which begins  to open  in the cen-
the human, parallel to each other, I think its use connected with this
parallel direction of the eyes, and have endeavoured to explain the con-
nection at large, in my Handbuch der vergleichenden Anstomie, p.  547. et
seq.
  As, on the one hand, this direction of the eyes renders one object visi-
ble to both at the  same time, and therefore more clearly visible ; so,  on
the other, this foramen  prevents the inconvenience of too intense a
light, if it is probable that it expands  and dilates a little, and thus re-
moves the principal focus from the very sensible centre of the retina.
  * Comment. Soc. Scient.  Gotting. torn. iv. p. 199.
  ! On the remarkable mutual relation of the arteries and nerves of the
internal parts of the eye,  and especially of the iris, see Diet. G, Kieser
De Anamorphosi Oculi.  Gotting. 1804, 4to.
  t This beautiful membrane was first discovered by Francis  Sandys,,
a celebrated maker of anatomical  preparations, and first described and 
150
OF SIGHT.
tre, at the seventh or eighth  month of pregnancy, when
the eyes have  acquired some degree  of size ; and when,
probably, the elliptic  arches  of its  vessels  begin  to  be
gradually retracted into the inner ring of the  iris, which
ring I have never been able to perceive distinctly before that
period.
  263.  The other circular membrane (260)  bears  the
name of ligamentum or corpus ciliare;  and inclining back-
wards, is distant from the iris.   Its external edge is thick,*
and adheres  to the ciliary circle (260): the internal is thin,
and adherent  to the margin  of the  capsule  of the lens.
The brown pigment is copiously diffused over it.
  Its  anterior  surface,  lying opposite to the   uvea, is
striated.  The posterior, lying upon the vitreous  humour,
is beautifully separated into about 70 flocculi, remarkable
for  an  indescribably minute  and  elegant  set of  blood-
vessels.  These  flocculi  are named  ciliary processes,  and
their use is still an object of enquiry.!
  264.  In the bulb of the eye, whose coats we  have now
described, are contained the  humours, of three principal
kinds.
  The  posterior,  and by  far  the  larger portion  of  the
globe,  is filled  by  the vitreous humour^ proportionally
larger in the human  subject, especially  after puberty, than
in other animals, and so  dispersed  in innumerable drops
exhibited in a plate by Ever. J. Wachendorf, Commerc. Litter. Nor. 1740.
Hebd. 18.
  * The ciliary eanal, discovered by Pel. Fontana {sur le venin de la vipere,
vol. ii. tab. vii. fig. 8, 9, 10,) and afterwards described more accurately by
Adolph. Murray, (nov. actor. Upsaliens. vol. iii.) runs, in  bisulcous animals,
along this thick edge.
  t Consult, among others, Brjmdis in his Pathologic p. 25.3. 
                        OF  SIGHT.                     151

 throughout  the  cells of  the. delicate  hyaloid membrane,
 that this membranaceo-lymphatic body  has the singular
 appearance of a tremulous jelly.
   265. Anteriorly it adheres to, and by means of the zona-
 ciliaris surrounds, the  capsule containing the crystalline
 lens, immediately around which lies the water of Morgagni.
   The lens itself  is very pellucid and cellular, but so much
 more  dense than  the vitreous humour,  that  it feels be-
 tween the fingers like a  very tenacious gluten, although
 amazingly clear.   Its nucleus  is more dense than the ex-
 terior lamellae.  These  may, by management, be reduced
 into extremely delicate fibres, converging from the circum-
 ference to the centre.*
   In the adult the lens is  proportionally smaller  than in
 quadruped mammalia;  also less convex, especially  on its
 posterior surface.
   266. The remaining space of the eye is filled by the
 aqueous humour,  which  is  very limpid, and divided by'
 the iris  into two  chambers; the anterior and larger sepa-
 rating the cornea  and iris; and the posterior, in  which the
 uvea lies towards  the corpus ciliare, so small, as scarcely
 believed  by some to  exist.
   267. These most valuable parts  are defended from in-
juries, both by the profundity of their situation  in the or-
 bits, and by the valvular coverings of the eye-lids.
   In the  duplicature  of the palpebrce  lie  the sebaceous
follicles  of Meibomius,!  thickly  distributed;   and   their
* Th. Young in the Philos. Trans. 1793, fol. XX. fig. 2, 3.
Dav. Hosack, ib. 1794, tab. xvii. fig. 4.
J. C. Red De lentis crystallina structura fibrosa.  Hal. 1794, 8vo.
! Ii. Meibomius' De vasis Palpebrarum novis ep.  Helmst. 1666, 4to. 
152
OF SIGHT.
 edges are fringed by a treble or quadruple scries of cilia:*
 the  cartilaginous  tarsi  serve  for their support and ex-
 pansion, and also facilitate their motion upon the eye-
 ball.
   Above the eye-lids, to use  the words of Cicero, the
 skin  is  covered by the supercilia, which preserve the eyes
 from the sweat flowing from the head  and forehead, and
 in some measure screen them from too strong a light.
   268.  To lubricate  the eyes,  to  preserve their bright-
 ness, and wash away foreign matters, is  the  office of the
 tears.   Their chief source is a conglomerate gland, placed
 in the upper and  exterior part of the orbit.  It has nu-
 merous but  very fine  excreting ducts,  which are  said to
 discharge about two ounces of tears upon  each eye during
 twenty-four hours;  the  tears are afterwards  absorbed by
 the puncta lachrymalia, the  function  of which  may,  in a
 certain  sense, be compared to  that of  the  lacteals  in the
villous  coat of the small intestines: from  the  puncta they
 are conveyed through the snail's horns, as they are called,
 into  the lachrymal  sac, and  thence pass into the  lower
meatus  of the nostrils.!(A.)
  269.  Thus much it was necessary to  premise upon the
structure of  the organ  of vision.  We  now  come to the
function of the organ,—to the explanation of vision.
  The rays of  light falling upon the  cornea at an angle
more acute than forty-eight degrees, pass through it, and,
from both its density and figure, are considerably refracted
towards the  axis of  the eye.  On entering  the aqueous
  * B. S. Albinus' Annot. Acad. L. iii. tab. iii. fig. 4.
  ! I. Chr. Rosenmiiller.  Organa Lachrymaliun Partiumque Externamm
Oculi Humani Descriptio Anatomka.  Lips. 1797, 4to. 
QF SIGHT.
B3
humour  they experience  rather  a less  degree of  refrac-
tion.
  Those rays which penetrate the pupil and are received
by the  lens,  are still  more  refracted  on account of the
greater density of this medium.
  The less density of the  vitreous humour prevents the
focus of rays from being  too small,  but allows it to fall
elongated upon the retina,  and  exhibit the  image of ob-
jects, inverse indeed necessarily from the laws of light.
  270.  The focus  which,  in  this mode, falls upon the
retina,  is  considered  as  acute,  not absolutely but rela-
tively, on account of the different refrangibility of colours ;
but the  latitude arising from this aberration of the rays,
is so small, that it not only does not obscure the clearness
of vision, in any perceptible degree, but is the source  of
many advantages.*
  271.  The celebrated question, why  we behold  objects
erect, while  their  image is painted  inversely upon the
retina,!  may be easily answered, by considering  that ob-
jects are called inverse   in relation  only  to  those which
appear erect.
   Now, since the  images of all objects  and  of our own
bodies are  painted on the retina, all in their relative  situa-
tion, their  relative situation  must  correspond as  exactly
as if they  were viewed erect, so  that the  mind (to which
a sensation excited  by the  image and  not the image itself
is communicated) is preserved from all  danger of error.
  * See Nev. Maskelyne's Attempt to explain a Difficulty in the Theory of
Vision, depending on the different Refrangibility of Light.  Philos. Trans.
Vol. lxxix. p. 256.
  f See J. II. Voight in the Mugazin fur Physik und Naturgescldchte.  T.
v. P. iii. p. 143.
                            X 
154                    OF  SIGHT.
   272.  Since  many  conditions  are  required for distinct
 vision, the Creator has wonderfully ordered the  functions
 of these organs.
   A sufficient, but, at the same time, a definite quantity
 of light, not too intense  for distinct vision,  is provided  in
 two modes:—First, according to the greater or  less inten-
 sity of the rays, a less or greater number of them passes
 to the lens:—Secondly, that portion which is superabun-
 dant and injurious to vision, is absorbed.
   The first is  effected by the motion  of the iris;  the se-
 cond, by the pigmentum nigrum.
   273. The iris  is endowed  with  sufficient  mobility  to
 accommodate itself to the intensity  and  distance of light,
 that when exposed to a  strong light or to near objects, it
 may expand itself and contract  the  pupil,  but  when to. a
 weaker  light or  more remote  objects,  it  may contract
 itself and dilate the pupil.*  Physiologists have given dif-
 ferent  explanations  of this motion.   Some ascribe  it  to
 the  impulse of blood into  its  vessels; others  to  con-
 traction of its imaginary  muscular fibres.  I have shewn,
 in a  particular treatise, that both these circumstances are
 impossible, and that it is by  far more probable  and na-
 tural to ascribe its  proximate  cause to the  vita propria of
the iris  (42);  the  more  remote  cause,  as  we  formerly
 hinted  (56), is to be sought for solely in the reaction of
 the sensorium.!
  274.  The  function of the dark pigment,  so frequently
  •  Zinn De Motu Uvea,  1757, in the Comment. Society Scient. Got-
ting. T. i.
  Fel. Fontana Dei Moti dell 'Iride.  Lucca. 1765, 8vo.
  ! For other explanations consult Troxler in Himly's  Ophthalmol. Bib-
Uoth.  T. h P. «• P- 21. 
OF SIGHT.
155
 mentioned, (258, 261, 263,) viz. to absorb the superfluous
rays, and its  importance to the perfection of vision, are
demonstrated, among other  ways, by the  dissection of
different  kinds of animals, and by the diseased condition
of Albinos, whose  eyes are very tender  and impatient of
light from the absence of this pigment.*
  275.  The focus of  the  refracted  rays must fall exactly
on the  retina, so that the  point of vision be neither pro-
duced  beyond it,   nor so shortened  as to strike on the
vitreous body.
  The  latter  defect  exists in short-sighted  persons,  from
the too great convexity of the cornea, or gibbosity of the
lens.
  The  former  is  the defect of long-sighted persons, in
whom there is the opposite conformation of parts.
  276.  Since  a  perfect  and sound eye beholds near and
remote  objects with equal distinctness,  it must  of neces-
sity  be supplied with appropriate powers of  accommo-
dation.!  That these internal changes of the eye are chiefly
accomplished  by the  pressure of the  straight muscles of
the ball,  I am clearly convinced, from this  among  other
arguments,—that in the Greenland whale, an amphibious
animal  which  must see in  media of different densities,
nature  has most accurately  provided for  this,  in the re-
markable  structure   and  obsequious   flexibility  of the
sclerotica.! (B)
  * 1 have spoken of Albinos at large, in my work De Generis Humani
Varietate Nativa, ed. 3. p. 274, and in my dissertation  De Oculis Leu-
cccthiopum.
  ! H. W. Math. Olbers  De  Oculi Mutationibus Intends.  Gotting.
1780. 4to.
  Ever. Home in the Philos. Trans. 1795, p. 1.
  t Co-mment. Socict. Scitnt. Gottingens.  T. vii. p. 62. fig. 11. f.g. b- 
156
OF SIGHT.
   277. During the waking state, the eyes are perpetually,
 although insensibly,  agitated,  and directed  towards  the
 axes of objects, by these muscles.
   For,  although the whole  of the retina is sensible,  it
 is not all  equally calculated to  receive the  images  of
 objects.
   In the first place, the  true axis of the  human* eye,
 where the optic nerve enters,  is  proved by the well-known
 experiment of Mariote,!  to  be nearly insensbile to light.
 The principal focus of the other part of the retina, and
 which must  be considered as  the chief instrument of dis-
 tinct  vision,  falls  upon an imaginary  axis  of the globe,
 corresponding with  the axis of  the cornea and the whole
 eye.   This,  however,  as  Keinster observes in opposition
 to Boerhaave, is not to be understood as  if only one point
 of an object could be seen  distinctly at once, while the eye
 is fixed,  and that,  to behold another point,  the  axis  of the
 eye must be changed;  for the sensation  of a complete
 object is simple and complete.!
   278. The  habit of directing the axis of the eyes rapidly
 towards  objects is acquired by practice.  This is proved
 by the example of  persons who were  born blind, but have
recovered their  sight  after  puberty ;§  and of children,
  * 1 say the human eye;  for in some animals now before me, the
seal and porcupine, for  instance, the true and imaguiary axis are the
same, the optic nerve lying exactly opposite the centre of the cornea and
pupil.
  ! Troxler speaks of this at large. 1. c. T. ii. P. ii. p. i.
  $ In Optica Quadam Boerhaavii et Halleri  Commentatur Abr. Gotth.
Kaestner. Lips. 1785, 8vo. p. 7.
  § See Giov. Bartolozzi sopra una cieca nata guarita. Veron. 1781, 8vo.
p. 99. sq. 
OF SIGHT.
1*7
who seldom  acquire  this  facility  of motion before  the
third month.
   279. To habit we must ascribe also the circumstance of
beholding  an object singly,  although we have two  eyes.*
For infants at  first see  double,  and the double  vision
which occasionally remains  after  certain  diseases  of  the
eyes, may be removed by practice and experience.
   280. The combined power of the  two eyes does not ex-
ceed, according to Jurin, that of each, by more  than  one
tenth part.
   It is  needless to  add,  what  the celebrated  painter,.
Leonardo da Vinci, long since remarked,—that  in view-
ing distant objects, it  is preferable to employ  but   one
eye.!
   281. Sight can never occur, unless the angle of vision
is at least  more than 34 seconds.   This  was  proved by
the very beautiful experiments of the acute  Tob.  Mayer
wfyo .formerly was one of our number.  And he demon-
strated the great excellence of the human  sight,  by shew-
ing that this still remained the limit of vision under  any
light, under the splendor of the  meridian  sun,  and  the
gloom of a lantern;  so that vision remains almost equally
clear, although the light be considerably diminished.!
   282. We may hence infer the prodigious minuteness of
the images of objects projected  upon the  retina,^   and
  * W. C. Wells's Essay upon single Vision with two eyes.  Lond. 1792,
8vo.
  ! Consult Lambert sur la partie photometrique de V art du peintre in the
Mem. de I'Acad. des Sciences de Berlin, 1768, p. 80, sq.
  $ Tob. Mayer's Experimenta circa visus aciem,  in the Commentar. Soc.
Scient. Gottingen, T. iv.
  § De la Hire, accidens de la vue, p. 375. 
158                     OF SIGHT.
nevertheless impressed  so  forcibly upon  it, that, undar
certain  circumstances,   their  vestiges remain,  after  the
removal of the objects from before the eye.*
                         NOTES.

   (A)  I  am  not satisfied with any account which I  have
kitherto seen,  of the function of the  eyelids, with respect
to the tears.  If I  am  not mistaken, the  tears  pass over
the ball of the eye  as low  as the  edge  of  the superior
tarsus,  which is so applied to the ball as not  ordinarily to
allow of their ready escape under  it-!  As the lids cover
the eye during sleep and their  fine inner edges meet, the
whole of  the ball is at this time readily preserved moist.
But when the  eyes  are open, the front of  the eye between
the lids would not be moistened  unless the upper tarsus
occasionally descended  with the   fluid contained behind
it.  The  fluid  thus brought upon the front of  the eye,
trickles down by its gravity as  far  as the  inferior tarsus,
which  also occasionally ascending,  raises it  somewhat.
  * Gassendi's vita Peireskii, p. 175, sq.  Hague, 1655, 4to.
  Franklin's Litters  on Philosophical  Subjects, at the end of his  Expts.
on Electricity. Lond.  1769, 4to. p. 469, sq.
  Rob.  War. Darwin's Experimenta nova de spectris  s. imaginibus ocula-
ribus, qua objectis lucidioribus antea vi.is, in oculo clauso vel averso per-
cipiunt.r.  Lugd. Bat. 1785, 4to.
  E;\ Di-rwin's Zoonomia, T. i.
  C. Himly in the Biblioth. Ophthalmolog. T. i. P. ii. p. i.
  | The object of this firm application of the tarsi to the «ye must be the
exclusion of  foreign matters from the orbit. 
OF SIGHT
159
Winking thus  preserves  the  front  of the  eye constantly
moist during the waking state.
   It may be also observed that when the  tarsi  approxi-
mate, as they drive before them the moisture of  the front
of  the  eye-ball, they quite  inundate  the  puncta lachry-
malia, by  which  circumstance  the puncta  are of  course
enabled  to  carry off  a  large quantity of  the  secretion,
and ordinarily  to  prevent  its  overflow, which would occur
at the centre of the lower tarsus.  During sleep the puncta
are not so copiously supplied, as they have only  the same
share of tears  as  the  eye in general; and there  is less
occasion for it, because the removal of the stimulus of the
air and  light  by  the  riosure of the  eyelids, lessens  the
secretion.
   M. Majendie  has found the matter  of  the  tarsal  or
Meibomian glands  to be not sebaceous but  albuminous,
and soluble in the tears;  hence we discover why, during
sleep, it accumulates  on  the tarsi;—because its  solvent,
the tears, are not sufficiently  abundant to remove it.
   (B) In Albino animals, whether the rabbit, pigeon,
or mouse,  the  sclerotic  and chorioid  are nearly  transpa-
rent, the latter losing its blood  after death,  and the image
formed  upon the retina may  be readily seen, without re-
moving a portion of the sclerotic.    From  observations of
this kind M. Majendie has found that whether the eye  be
presented to a  neighbouring or distant object, the image
upon  the retina is equally distinct, and  therefore all  the
explanations of this circumstance  which have been hither-
to  given,  founded  on  changes  which  can  occur  only
during life, fall  to the ground, whether founded on pressure
of the ball by the recti muscles, motion of the crystalline,
contraction of the crystalline or  ciliary processes, &c.  He
also found that the escape of a little  of the  aqueous  or 
160
OF SIGHT.
vitreous humour, or the total removal of the former or of
the cornea, impaired the distinctness of the image;  the
total removal of the aqueous humour or of the crystalline
also  increased the size  of the  image; the removal of the
humours prevented the formation of  any image;  an in-
crease produced in the pupil by a circular incision of the
iris produced an increase of  the image.*
* Pre'cis Elementaire de Physiologie, T. i. p. 61, sq. 
OF THE  V0LUNTA11Y MOTIONS.
164
                    SECT.  XVIII.


              OF THE VOLUNTARY MOTIONS*


   283. We  have  seen  that  the  nerves perform  two
 offices:  (220) the one of feeling, the other of  moving.
 The former  we have already considered;  we shall  now
 say something with respect to the latter.
   284.  All the motions of the body may be divided  into
 voluntary and involuntary.
   The  pulsation of trie heart, and the peristaltic motion
 of the intestines  and other  viscera,  are  commonly ad-
 duced as instances  of involuntary motion.
   The  action of by far  the greater  number of the other
 muscles is voluntary.
   Respiration,  sneezing,  the tension of  the membrana
 tympani,  the action of the  cremaster, are regarded by
 some as belonging to the former class; by others,  to the
 latter;  and by others, as of a mixed nature.
   285.  If this division  is narrowly examined,  it will be
 found embarrassed  by so many difficulties,  that  the limits
 of each class cannot well be determined.
   For,  on  the  one hand,  few functions can  be termed
 truly involuntary,  especially if we consider the connection
 of the imagination and passions with the will.
   Again,  on  the other hand, there  are   few  voluntary
motions that may not  be rendered involuntary by the force
of habit,  whose  influence upon  our animal motions is
 mmense. 
162
OF THE VOLUNTARY  MOTIONS.
   286.  Of  the  latter  description  are  those  muscular
motions  which, although  generally voluntary, take place,
under  certain  circumstances,  without  the knowledge  oi
the mind, or even in opposition to its endeavours.
   Thus  we wink  involuntarily,  if a friend  suddenly ap-
proaches his finger to one of our eyes,  though it does not
come in contact:  the ring finger generally  bends if we
bend the little finger.
   We  often unconsciously  move our  limbs  even while
sleeping soundly.
   On  the  contrary,  some muscles which are  almost al-
ways obedient to the will,  occasionally cease to be so:  an
instance of this  exists  in  the  difficulty which we experi-
ence  in attempting  to  move the hand  and  foot  of the
same side in different directions;  and in all those motions,
which,  although voluntary and perfectly easy if produced
separately, are found very difficult if attempted together.*
   287.  Among those motions which are  supposed to  be
perfectly involuntary,  no one is free from exception,  as
far as I know,  excepting the spasms of the uterus during
labour, f
   With  respect  to the  motion  of the  heart,  we have the
indubitable  testimony of Baynard and  Cheyne, that  they
saw the  famous  English officer, who could stop the  mo-
tion of his heart and arteries at pleasure.!
   There is no  question that the  pulsation of the heart and
  * Consult Winslow in the Mj-'m. di YAc.dss Saences de Paris, 1739.
  ! These are partly voluntary ii. some warm-blooded animals, as is sliewir
m birds when setting, which, if deprived of their eggs, are well  know v
to la/ others in succession.
  ±  Cheyne's Trect'.se on Nervous Diseases, p. 307, sq. 
OF  I HE VOLUNTARY MOTIONS.
163
arteries  can be accelerated or retarded by the varied state
of respiration.*
   The motion of  the  stomach  is voluntary in all rumi-
nating  animals,  and I  myself once  distinctly found it
voluntary in the  human subject,  in an instance of rumi-
nation.
   Although the motion of the  iris  is involuntary in most
persons, I  have  been credibly informed  that some have
been able,  by  a  considerable effort,  to subject it  to  the
will and contract  the pupil in a faint light.
   So  numerous  are  the  motions  commonly  called  in-
voluntary, which become voluntary in some  particular in-
dividuals,  especially  if aided  by attention  and  liveliness
of imagination-!
   Thus  I have  seen some able to produce at any time a
spasmodic horripilation of the skin, by representing some
unpleasant sensation to their imagination.
   Others have had the power  of exciting- local sweat in
the hands, &c! (A)
   288.  This may perhaps  be  explained on  the principle
of sensorial reaction, (56)  which  may be  produced  by
imagination,—a mental stimulus,  as easily as  by a corpo-
real stimulus  acting  upon the  sensorium  (52).   Manv
phenomena accord  admirably with this  explanation; v. c.
  * See Sam. Lath. Mitchill  On the gaseous oxyd  of azote &c.  New
lork, 1795, 12mo. p. 26.
  Also Leop Caldani in the Memore della accademia di Mantova.  T. i,
1795, p. 118.
  ! See the Rapport des Commissaires charge's par le  Roy  de I'examen du
■magne'tkme animal, written by J. Sylv. Bailly, a man worthy of a better
fate. Paris, 1784, 4to. p. 16.
  t Sec v. c. T. Bartholin in the Act. Hafniens, 1676, vol. iv. p. 19T. 
 ■ 64           OF THE VOLUNTARY MOTIONS.

ihe various causes of the erection of the penis, and of the
flow of saliva.
  2S9.  The voluntary motions are the distinguishing cha-
racteristics of  the animal from  the  vegetable  kingdom.
For no  plant  has been discovered  procuring for itself
food by means of voluntary motion; nor  any animal in-
capable of locomotion, or at least of procuring sustenance
by the voluntary motion of individual members.
  290.  In ourselves, these motions afford  a striking proof
of  the  intimate harmony subsisting between the bodv and
the mind; and which  is demonstrated in the rapid  and
various motions of  the  fingers of a good performer on the
harp, and of the vocal organs whenever we  speak.*
                        NOTE.

  (A)  Those  muscles I  conceive,  are  called voluntary,
which we ordinarily have the power of directly  contract-
ing: those involuntary, which we have not ordinarily the
power of  directly  contracting.    These  two definitions
appear to me unexceptionable.   The latter does not con-
tradict  what  is  unquestionably  true,—that  we  can  in-
directly affect  involuntary  muscles,  as  the heart or sto-
mach,  by thinking of certain objects,  and thus  exciting
certain emotions ;  nor does the former contradict another
truth,  that voluntary  muscles often contract without or
  * A person playing on the harp, dancing,  and  singing, at the
time, exercises about three hundred muscles  at once,  G. Ent's a
in Thrustoni diatribam, p. 130. 
              OF THE VOLUNTARY MOTIONS.           165

against our will.   And this  leads me to remark that the
respiratory muscles deserve the epithet voluntary as  much
as any in the body,  for we directly contract them: we
feel an uneasy sensation in the chest from the  retardation
which occurs to the blood,  and we  inspire to remove it;
the uneasiness  being removed, our  effort ceases, and ex-
piration spontaneously ensues.   It  is true that the uneasi-
ness  is  so great  that we are forced to inspire,  and  that
respiration continues while we  are  asleep.  But the  same
is true of all voluntary muscles.  If you  irritate  any part
of a person asleep,  an effort of some kind is made  to re-
move it;  and if you cause strong  pain  or titillation in a
person  awake, he will be compelled,  whatever  restraint
he may attempt upon himself,  to make an effort to remove
;t by motion of some  part,  as forcible as he is compelled
to remove the uneasiness in the chest by inspiration.*
* See A. P. Wilson in the Edinb. Med. and Surg. Journal, 1809. 
66
OF MUsCULAR MOTION.
                     SECT. XIX.

                  OF MUSCULAR MOTION.

   291. J he immediate organs of motion, by far the most
numerous  in the body,  are  the  muscles, which form  the
greatest bulk among all the similar parts.
   292. They abound  in azote more  than  other  animal
parts ;  and  the absence of this principle, from the  com-
bination of  hydrogen and  carbon,  which  exists  during
health, entirely converts them, under a particular morbid
affection*  and  after death!  into an adipocerous substance,
resembling soap or spermacete.
   293. The  muscles are distinguished from other  similar
parts  by  two  characteristic  features;  the  one  derived
from their  structure,  the other  from their singular vital
powers.
   294. This fleshy structure  is so constructed of moving
fibres,  sui generis,  and  of  a very faint red  colour,  that
every  muscle may be  resolved into  fibrous  bands,  these
into bundles of fibres,   and  these  again  into very fine
fleshy  fibrils.
  * For instance,  in Elephantiasis.  Consult Ph. Gabr. Hensler, Vom
Abendliindischen Aussatze  im Mutelalter,  p. 316.  Accurately  describ*
cd examples of similar changes  in other aft'ections, may be found in
Hedendaagsclie  Letter-tEfeningen, T. iv. P. ii. p. 45, and in the Me1 moires
de .Mafhematique, &c. presente's aK VAcademie  des  Sciences  de Paris,
T. vii. p. 301.
  ! See Thourcl in the Journal tie Physique, T. xxxviii. p. 255.
  0. Sm. Gibbes in the Philos. Trans. 1794, p. 169. 
OF MUSCULAR  MOTION.
167
         295.   Every  muscle  possesses  a  covering  of  cellular
       membrane,*  which is so interwoven with its substance, as
       to surround the bands,  the bundles, and even each par-
       ticular  fibril.
         296.  Every part of the  muscles is amply supplied with
       blood-vessels and  nervous  threads.   The latter  appear to
       deliquesce into  an  invisible  pulp,  and  unite  intimately
       with the  muscular  fibres :  the former  are  so interwoven
       with the fibres,  that the whole muscle is red, and  acquires
       its  own paleness (294) only by being washed.
         297.   Most muscles terminate in  tendons,! which are
       fibrous! parts,  but  so  different  in colour,  texture, elas-
       ticity, Sec. as to be readily distinguished from  muscles:
       thus disproving the opinion  of  some,  that the tendinous
       fibres originate  from  the  muscular.    This  error  arose
       chiefly  from the circumstance of the  muscles  of  infants
*       containing a greater number  of  fleshy fibres, in  propor-
       tion to  the tendinous, than those of  the  adult.
          298.  The other exclusive character of  muscles (293)  is
       the  irritability  of  Haller,§ the  notion of which, and its
  • See Ad. Murray, De Fascia Lata.  Upsal. 1777, 4to.
  ! See Fourcroy in the Me'moires de VAcademic des Sciences de Paris,
1785; p. 392, and 1786, p. 38.
  * Albinus, Annotat. Academ. L. iv. Tab. v. f. 2.
  § I thus  distinguish it, not because the luminary of the Gottingen
school first  discovered it, for he repeatedly bestowed praises upon the
opinions entertained with regard to it by his predecessors, from the time
of Glisson ;  but because he first investigated it as it deserved, illustrated
and enlarged upon it by numerous  living dissections,  and demonstrated
the great power and influence of the doctrine thus remodelled, upon the
animal economy.  I have also  another reason, viz. to distinguish it from
the irritability of the truly meritorious Caubius, who applied the same
term to the morbid sensibility of the living solid. 
1-68
OF MUSCtfLAR MOTION.
difference from  contractility, we formerly explained (41),
but shall now prosecute farther.
  299.  This irritability, or muscular power, or vis insita,
is bestowed upon all muscles, but in different degrees.*
  300.  The  highest order  are the hollow  muscles which
perform  the  vital  and  natural functions,  and  especialh
the  heart, (124) whose  internal  surface  enjoys  a  very
lively and permanent irritability.
  Next to the heart follows the intestinal  canal,  particu-
larly the small intestines, which, in  warm-blooded animals,
contract after the heart has  ceased to show signs of irri-
tability.
  Next the  stomach.
  Then the urinary  bladder, &c.
  Among the other muscles,  the  respiratory, v.  c.  the
diaphragm,  the  intercostals, and  triangularis  sterni, are
remarkable for their irritability.
  Then follow the remaining muscles.
  Less, but still however some, exists in the arteries (128).
  Also in the venous trunks contained in the thorax (95).
  Still less, if it deserve the name of irritability,  in the
other blood vessels. (132)
  301.  Haller, the great arbitrator in the doctrine of irri-
  * See Haller on the irritable parts in the Commentar. Soc. Sc.  Gotting.
&. ii. and in the Nov. Commentar. Gotting. T. iv.
  Among innumerable other writers on the same point, suffice it to. quote
the following:
  Zimmerman, De irritabilitate.  Gott. 1751, 4to.
  Oeder on the same.   Ilafn.  1752, 4to.
  J. Eberh. Audrey on the  same.  (Prss.  Ph.  Fr. Gmelin.)  Tubing.
1-758, 4to.
  Some others have been already mentioned, as well as three entire Cert.
lections of Writers, (p. 182.) 
OF MUSCULAR MOTION.
16?
 tability, has ascribed it  improperly  (40,  5807) I think, to
 some parts possessed indeed of contractility, but in which
 I have never been able  to detect genuine irritability.
   Such are the  lacteals,  glands, gall bladder,  uterus,  the
 dartos, and  the penis. (A)
   And others, with no less impropriety,  bestow  it upon
 the iris, the external surface  of the  lungs,  &c. in which
 it  no more  exists  than  in the  cellular  membrane  and
 those parts which are composed  of it,—the common inte-
 guments,  membranes  of  the brain,  pleura, peritonaeum,
 periosteum, medullary  membrane,  tendons,  aponeuroses,
 &c. or in the proper parenchyma, of the viscera, (20) of
 the  liver, spleen, kidnies, secundines, the  brain,  and the
 rest of the nervous system, every one of  which  parts is
 destitute alike of muscular fibre, and  of  what  is  peculiar
 to it,-i—irritability.
   302. As  we  find muscular  irritability sometimes con-
 founded with  the contractility of the mucous web;  so
 on the other hand, some eminent men,  particularly  in
 modern times, have attributed  it to the nervous energy.*
   Now, although we cannot deny the  influence  of the
nerves upon the muscles, most strikingly shewn of late (225)
by the experiments  of  the celebrated Galvani and  others,
and although no  muscular fibril, however  minute, can be
  * To this point chiefly belong the celebrated disputes respecting the
influence of nerves upon the motion of the heart, and the modus operandi
of opium upon the  heart and nerves.
  Consult, besides other authors already quoted,
  Rob. Whytt'a  Essay on the vital a?id other invohtntary motions of ani-
mals.  Edinb. 1751, 8vo. and  more at  large  in his  works, ib. 176b",
4to.
  J. Aug. Unz.er, erste Griindj einer Physiolog-ie djr c.p.-ntllcheri tberif.
chen natur  thierischer ICorpcr.  Leipsig. 1771, 8vo.
                             Z 
 170               OF MUSCULAR  M0T1O.Y

 found absolutely destitute of nervous pulp, we are not on
 this account to assert that  irritability  is not  a power sui
generis, as clearly different  from the nervous energy as
 from contractility.  For parts not muscular  are  not irri-
 table,  however  abundantly they  may be supplied  with
nerves, as  the corium,  the numerous  nervous  viscera;
 and the muscular texture  alone  exhibits the  genuine phe-
nomena of irritability.   So that  from  the  weight  of these
united arguments,  to omit many others, it appears more
just to  assign these  phenomena  to  the  muscular  fibre
alone,  than to  ascribe  them  to the  nerves,  which  are
common to so many other parts,  but do not  in these
excite  the  faintest  sign of irritability.  I  say nothing of
many  weighty arguments derived, for instance, from the
facts,  that  no proportion  exists between  the  degree of
irritability  and the number of nerves in  any  part;  that
one  description of vital  powers is  often  very energetic,
while  the  other  is languid  in  the  same  individual, ac-
cording to national, morbid, or more especially to sexual
variety. (B)
  303. The nerves exert their influence upon the muscles,
as remote or exciting causes  of  their  action,  but by no
means as the proximate  or efficient,  which is the inherent
irritability of the muscles.
  The passions,  v. c. act upon  the  sensorium, this upon
the nerves of the heart, so as to excite its irritability, which
produces palpitation and other anomalous motions.
  The will  acts upon the sensorium, this reacts upon  the
nerves of the  arm, which excite muscular motion, as re-
mote causes;  but. the proximate cause is  the irritability
of the muscles themselves.
  304. With this distinction of the two causes of mus-
cular motion,, the result of those experiments  exactly cor- 
OF MUSCULAR
MOTION.
171
respond,  which have been so frequently made by dividing
or  tying  the nerves.*   Paralysis ensued,  but irritability
continued vigorous for a length of time afterwards.
  There  have been cases where  one limb was motionless
from paralysis, but retained its sensibility, while the other
was insensible,  but  still capable of motion.]   Others have
had great pain in paralytic parts.!
  305. The true efficacy of the blood so copiously afforded
to muscles, (296) in promoting their action,  is. not clearly
ascertained.
  In the Stenonian experiment,^   indeed, paralysis of the
hind legs commonly follows  the  application of a ligature
upon the  abdominal aorta.jj (C)
  But  after all,  I am confirmed in the  opinion formerly
mentioned (125),  that the  action of what  are commonly
called  voluntary  muscles  depends less than  that  of the
heart, upon the  afHux of blood' to the moving fibres;  and
on the contaray,  more than it, upon the influence  of the
nerves which excite their irritability.
  306.  Besides these inherent powers common to all mus-
cles,  there are  some  peculiar and  adventitious,  arising
from figure, situation, &c. and answering their object with
perfect accuracy.
  307.  From this  circumstance,  the  muscles in general
  • J. H. v. Brunn's Experimenta  Circa Ligaturas Nervorum in vivis . 7.i«
malibus Inslituta.  Gotting. 1753, 4to.
  ! v. J. Stewart, De Systemalie Nervosi Qff/ciis.  Edinb. 8vo.
  $ C. H. PfafF, uber  Tfuerische  Elektricitiit und Reizbarkcit.  Leipsi^,
1795, 8vo. p. 263.
  § Stenon's Elementor. Myologi.e spec.  Floreut, 1667, 4to. p. 86.
  fl See Courten in the Pliilos. Trans. No- .3)5, p. 500, and lluller in the
Continent. Sue. Sc. Gotting. T, iv. p. 295 
OF MUt>CULAR
MOTION.
 are  divided into hollow and  sollid.  The  former,  as we
 have seen, not directly subject  to the will, belong more
 to the vital  and natural functions, and  are consequently
 not to be considered at  present, while we are  speaking of
 the  voluntary muscles,  which  belong  to  the order of
 animal functions.
   308.  Among the latter also, there is much variety.  For,
 not to allude  to difference of size,  there is great variety
 in the disposition of their bands and  fasciculi,  and the di-
 rection of their fibres, in the proportion of the fleshy to
 the tendinous part, in their course, mode  of insertion, &c.
   309. The greatest  number are long, and their fleshy
 bellies terminate  at  each extremity in  tendinous  chords,
 inert,  and destitute  of irritability, and fixed to the bones,
 which they move in the manner of levers.
  310. While a very few muscles are  destitute of tendons,
 such as the latissimus colli,  an equally small number  are
 not inserted into bones, such are the cremaster, as we ge-
 nerally find it, the azygos uvula?, most of  the muscles of
 the eye, &c.
  311. The  muscles  endowed with those  common (298
 sq.)  and  peculiar (306 sq.)  powers,  are  thus prepared to
 perform  their actions, which  also  may  be divided  into
 common and  peculiar.
  312. A property common  to all muscles,  and the imme-
 diate consequence of their.irritability, is to become shorter,
more rigid, and  generally unequal, and, as it were,  an-
gular, during contraction.
  To attempt with J. and D. Bernoulli and  other  mathe-
matical physicians, to reduce this diminution to a general
admeasurement,  is  rendered  impossible,   among  other
causes,  by  the great  difference  between the hollow and
solid muscles  in this  respect,' and between the  solid mus- 
OF MUSCULAR MOTION.
173
cles themselves, v. c.  between straight  muscles (such as
the intercqstals) and sphincters.
   313. The peculiar actions of muscles (311) correspond
with their peculiar powers, and consequently vary so much
as to be referable to no general laws.
   To cite one instance out of many, that action of certain
muscles  is peculiar  and anomalous, which seldom occurs
alone, but nearly always subsequently to, or simultaneously
with  the  action of  some of a different order.   Such is
the action of the lumbricales,  when, during rapid motions
of the fingers, they  follow  the  action  of other muscles
of the metacarpus and fore  arm; and of the lateral recti
muscles  of the eyes, either adducens  of which seldom
acts, unless  simultaneously with the abducens of the  other
eye.
   The commonly  received  law,—that a muscle during its
contraction draws  the more moveable  point  of  insertion
to the more fixed, must be  considered,  as Winslow wisely
remarks,* perfectly relative, and  subject to different limi-
tations.   Thus, for example,  sometimes the one point,
and sometimes the other, may  be the more moveable ; ac-
cordingly, as the united  action of  many different muscles
may render the opposite more fixed.
   And,  on the other hand, although  the action of  the
flexors  is generally  so much stronger  than  that of their
antagonists,---the extensors,  that,  when  the bodyis at rest,
the arms, fingers, &c. are  a little bent, this does not so
much depend  upon  the strength of the contraction  of
the flexors,  as  upon  the voluntary relaxation of the  ex-
tensors, for  our own relief.
• Me'ih. de I'Acad. des Scienc, de Paris, 1720. 
174
OF MUSCULAR  MO'WON.
   314. Every muscle has moreover a peculiar mechanism*
 adapted to the individual motions for which it is intended.
 Besides the determinate figure of each, many, other kinds
 of assistance are  afforded to their  peculiar motions.   The
 bursa  mucosa:, chiefly found  among the  muscles of the
 extremities;  the  annular ligaments  by which some  are
 surrounded; the  fat in which most are  imbedded;  the
 lymphatic vapour  around each;  and, above  all, the  con-
 formation of the  sceleton, chiefly in regard to apophyses,
 condyles,  and the articulations ;  nay, even whole bones,
 v. c. the patella,  the pisiform of the carpus, and the  sesa-
 moid bones ;! are destined solely to facilitate the actions^
 of certain muscles.
   315. In this  mode is compensated, or at least diminish-
 ed,  that  inevitable loss of power,  which necessarily takes
 place  from  the  conformation  and stature of  the  whole
 system, in which, from the acute  angle  at  which  some
 muscles are inserted,  or the  proximity of their insertion
 to the centre of motion, much of that power is lost, which
 would have existed,  if their insertion had been more re-
 mote or at a<more obtuse angle-!
   316. The human body, possessing 450 muscles, or even
 more,  according  to sexual or  individual  variety, is thus
 furnished  with a double advantage,—with  an  extreme
 agility of  motion  in particular parts and throughout the

    ,   -__„ ■■                             ■     ,  j____________

  • P. J. Barther. Nouvelle Mechanique des Mouvemens de VHomme, et des
Animaux.  Carcass. 1798. 4to.
  ! Hence, of all animals which 1 have dissected,  the mole is supplied
with the most remarkable apparatus of sesamoid bones ;  its anterior pal-
mated feet, with which it digs, have many of these bones, which greatty
facilitate the action of the brachial muscles.
  fc Gilb. Blane on Muscular Motion, p. 51.- 
OF MUSCULAR  MOTIOU.
175
Avhole; and with a surprising degree of strength and  en-
durance of  labour.  Both these are accomplished partly
by the perfection of the muscles, which, like the perfection
of ossification, takes place at  manhood;  and partly by
habit and  practice,  the  former  of which  in affording
strength and agility to the  muscles,  is demonstrated in
rope-dancers, leapers, runners, wrestlers, porters, savages,
and in  the examples of ancient nations.!
                        NOTES.,

   (A)  Irritability is a power of contracting upon the  ap-
plication  of a  stimulus,  ceasing  with  life.   It  compre-
hends animal  and organic contractility,  (See  Note  to
Sect, vi.)  and  we  must  suppose the lacteals, vessels of
glands, gall bladder and dartos to be possessed of it:  the
uterus will  hereafter be shewn positively to have muscular
fibres, and  their existence will  be  rendered probable  in
the human penis.
   (B) See Note F. Sect. xii.
   (C) This paralysis  does not show the irritability of  the
muscles  to  be  impaired;  they would doubtless  contract
immediately after  this experiment,  upon  the application
of a stimulus, as readily as they do after apoplexv.  The
ligatures act immediately by depriving  the nerves of  the
  •  I Iwve treated on this point at large, in the Medic, Biblioth.  Vol, ii;*
p 407 
176
OF MUSCULAR MOTION
power of stimulating them; for a supply of arterial blood
is necessary to the  function of the nervous system,* and
the ligature of the abdominal aorta cuts this off from the-
lower part of the spinal marrow, and what originate from
it,—the nerves of the hind legs.   If venous  blood is sent
to the brain, death ensues, and the function of  any part is
destroyed  by forcing venous  blood into its arteries-!
   Another source of paralysis must ultimately arise,—the
loss of irritability from the  want of circulation  in the
muscle.
* Le Gallois, Sur le Principe de la Vie.
t Bichat, Re'c/ierches Physiologiques. 
OF SLEEP.
                      SECT.  XX.

                        OF SLEEP.

   317. 1 he faculties both  of feeling  and motion, pos-
 sessed by  the  nervous  system  whose  history  we  have
 thus  pursued,  are  so fatigued by their exertions in the
 day,  that rest  is  necessary  during the  night to recruit
 them by means  of sleep,*—-the image of death.
   318. Sleep is a periodical  function,  by which the interi
 course of the  mind  and body is  suspended, and whose
 phenomena now to be traced,  correspond very aptly with
 the supposition of a nervous fluid.
   319. Besides other precursors of sleep j  may be enume-
 rated a gradually increasing dulness of the external senses,
 and a relaxation of most, especially of the long, voluntary
 muscles;  a congestion of venous blood about the heart,
 and relief afforded by  yawning to the uneasy  sensation
thus produced :  lastly, a curious kind of short delirium at
 the moment when sleep is all  but present.f
   320. The  phenomena  of  sleep,  therefore,  amount  to
 this,'—that the animal  functions are  suspended,  and all the
 rest proceed  more  slowly and inactively.   For the pulse
 is  slower,  the animal heat,  caeteris paribus, diminished,
perspiration more sparing, digestion imperfect, and nearly
  * Consult, among authors hereafter to be recommended, Er. Darwin*
Zoonomia. T. i. Sect, xviii.
  f De Pauw has some singular observations upon it in bis Recherches
.*;■■■• les Eqyptiens et les Chinoi-i.  T. ii. p. 159.
                             a a 
\n
or sLEtr.
all  the excretions  (except that of the semen,  which i^
indeed rather unusual) suppressed.  (A)
  321.  The remote causes of sleep are evident.*  To  say
nothing of narcotics,  it  is induced by the expenditure of
the animal powers  from  previous  fatigue or watchfulness,
also by habit, darkness,  silence, rest, &c. which acquire
their somnferous  powers in some measure  from  habit;
by mild,  continued, and uniform impressions upon  certain
senses, v. c.   the  murmur of a rivulet, or the view of a
fit-Id of standing corn agitated by the wind,  a previous
meal,  intense cold applied to the surface, and other  modes
of  deriving  blood  from  the  head, as pediluvia,  clysters,
profuse hemorrhages.
  322. These remote  causes  may induce  the proximate.
cause,  which,  upon mature  consideration,  I  think pro-
bably consists in a diminished  or   impeded flow of  oxyge-
nated  (arterial)  blood to the  brain, for that fluid is of the
highest  importance,  during   the  waking  state,  to  the
reaction of the  sensorium upon the senses and voluntary
motions.!
  * Although the  lethargic winter torpor of th2 Alpine marmot, the
cricetum, and many othtr brute  mammalia, differs importantly from
the sleep now spoken of;  modern observations respecting this torpor
have shewn, that, in their phenomena and remote causes,  both correspond
and mutually elucidate each other.  Consult, for instance, Sulzer. Natur-
geschichte des Hamsters, p. 162.
  Spallanzani, Sur la Respiration.  Geneva. 1803,  8vo.
  Mangili, and C.  Ul. Von Salis in the latter's and Steinmuller's Alpina.
T. iv.  1809.
  Cuvier's Analyse des Travaux de la Classe  Physique  de  Vlnstiiut.
1807.
  ■f- Those who wish to  know and compare other opinions upon the
causes of sleep, may consult M. De Grimaud's Me'm'ri,- s'tr la N:triuon.
Peterab. 1789.  4to. p 194. 
OF SLEEP.
179
  The influx of blood is diminished by its derivation from
the brain and congestion in other parts; it is impeded by
the pressure  of foreign matter upon the brain, whether
from  serous or  purulent collections,  from  depression of
fracfired bones, &c.
  This diminution of, or impediment to, the flow of blood
to the  brain, causes a deficiency of  water in the ventricles
and a  collapse of them, upon which that acute and deep
physiologist,  David  Hartley,  on  whom  we  formerly be-
stowed praise, explains the various phenomena of dreams.*
Besides other phenomena  which  accord with this  expla-
nation, one  is  very, remarkable  which I witnessed in a
living person, and has  been already noticed,—that  of the
brain  sinking whenever he was asleep, and swelling again
with blood the moment he  awoke.
   This opinion is likewise strengthened by the production
of continued watchfulness from congestion of blood in the
head.
   323.  The  quantity  of sleep depends much upon  age,
constitution,  temperament, &c.;  generally speaking, much
  Am. Wienholt in  the Heilkraft des thierischen Magnetismus.  T. ii.
p. 439.
  H. Xudow.  Versuch einer Theorie des Schlafs.  Ratisbon, 1791, 8vo.
  Steph- GaUhii at the end of his Saggio cf Osservazioid Sui Nuovi Pro-
r>:3si Delia Fisica del Corpo Umano.   Padua, 1792, 8vo.
  Manduit in Fourcroy in the Mt/decine Eclaire'e, &c. T. iv. p. 273.
  T- Chr. Keil Functiones Organa Animce Peculiares.  Hal. 1794, 8vo. p.
108.
  L. II. Chr. Niemeyer Matcrialien zur Erregunstheorie.  Gotting. 1800,
8vo. p. 71.
  Troxler. Versuche in der Organischen PJnjuik, p. 435
  Brandts Pathologie, p. 534.
  * Observ. on Man.  Vol. i. p. 48., 
180
OF SLEEP.
sleep is  the  attendant of weakness, (as we find it in in-
fants born  prematurely and in  superannuated persons,)
and the very frequent source of fatuity and torpor.
  324. We awake refreshed with  sleep; and this return
to life is attended by the same phenomena as the approach,
of sleep,—by  gaping,  usually  attended with stretching,
by some  degree of dulness of the senses, &c.
  325. The  causes of  waking  correspond  with those of
sleeping.
  The proximate is the more free  return of blood to  the
head.
  The remote are  (besides the power of custom, which is
in this  respect very  great) various stimuli applied to  the
external  or internal  senses, either immediately affecting
the nervous system,  as  the  distension of the bladder, or
mediately, by  the  intervention of  the  imagination, as in
dreaming.
  326. Dreams are a wandering of the imagination, which
recalls the ideas of objects formerly  perceived, especially
of objects of  sight, and appears  to  employ and interest
itself with them.
  It has been disputed whether dreams are natural during
health.   Some believe that they always occur during sleep,
although they may escape our memory.*  Others conceive
them the consequence  only  of derangement in some of
the abdominal  viscera.!  Very healthy adults have asserted
that they never dreamt.!
  • Consult Kant. Critik der Urtheilskraft p. 298. and Anthropologic,
p. 80.
  ! v. F. Xav. Mezler von der Schvtarzgallichten Constitution, p. 80.
  t v. Locke's Essay  concerning Human Understanding.  Vol. i. p. 74.
Lxmd. 1726. 8vo. 
OF SLEEP.
181
  They  are generally  confused  and  irregular, but occa-
sionally discover extraordinary marks of reason.*
  The power of corporeal  stimulants is very great in pro-
ducing dreams;  v. c. of the semen in producing lascivious
trains of ideas, of excessive  repletion  in causing frightful
appearances.   We have one instance of a  man, in  whom
any kind of dreams could  be  induced, if his friends, by
gently addressing him, afforded the subject matter.!  This,
however,  appears to  be  a  preternatural  state,  between
sleeping and waking; as does also  the truly diseased case
of  sleep-walkers,  and  that affection  which  seizes them
with what  is termed magnetic  ecstacy, which is, however,
of  a very different nature.\
   Locke and others have regarded all  dreams  as a specieg
of  this mixed state.  (C)
                        NOTES.

  (A) Respiration also proceeds  more slowly.
  (B) It is certain  that  the  supply of arterial blood to
every part,  and especially to the nervous system, is requi-
site to its functions and its life, and that in  proportion to
the activity of a part is the activity of its supply of arterial
  * See for instance what Hollmann has related of himself in  this par-
ticular. Pneumatolog.  Psycholog. et Theol JVatural.   Gotting. 1780, 8vo.
p. 196.
  ! Beattie's Dissertations Moral  and Critical.   Lond.  1783, 4to. p.
217.
  ! G. Gottl. Richter De Statu Mixta somni et Vigiti* qua Dormientes multa
VigUantium munera obeunt. Gotting. 1756, 4to.
  Wienhott, 1. c. Vol. iii. P. i. p. 10. 
182
OF SLEEP.
blood.   Analogy, therefore, renders it more than probable,
that, during the inactivity of sleep, the brain  having less
occasion for arterial blood,  has a less vigorous circulation
than during the waking state ;  and we know that whatever
diminishes the ordinary determination of blood to the brain
(321), or impairs  the movement of the blood through it,*
disposes to sleep.!  But although  this be granted, it must
be  viewed  not as the  ordinary  cause, but as  a  circum-
stance,  or  in  fact  a consequence,  of  sleep.   Increase  the
activity of an  organ, you  increase its  circulation;   dimi-
nish  its activity, you diminish its circulation.   The  altera-
tion of circulation  is usually not  the cause, but the con-
sequence ;  necessary  indeed  to the continuance  of  the
altered  degree of  activity in the organ, but not the  cause.
The  degree of activity  of any part,  and the degree of its
  * As arterial blood when at rest acquires the venous character, it is evi-
dent that in congestion of blood, by which is meant an unusual quantity
of blood in a part, not moving with its usual freedom,  the part affected
has  not  its proper supply of arterial blood.  Hence congestion in the
head must, from this cause alone, produce drowsiness.
  ! The phenomena of torpid animals are precisely analogous to those
of common sleep.   The seniibility and all the functions are lessened, the
temperature is low, the circulation slow,  respiration almost or quite im.
perceptible, and digestif suspended.   This torpidity is produced by
a deficiency of external excitants, usually by cold and want of food, and
in the language of Brown, is a state of direct debility, while our ordinary
sleep is one of indirect debility. No structural peculiarity is discoverable,
which enables certain animals to  live through torpidity..  S«e Dr. Jfeeve
On  Torpidity.
  Some animals become torpid on being deprived of moisture.  I .put a
garden snail into a dry closet without food  a year and a -half ago;  it
became torpid and has remained  so ever since, except whenever I  have
chosen to moisten it:—a.few drops of water revive it at any time.  Moist-
ure has revived some animalcules  after a torpidity of twenty-seyen .years.
Spallanzani.  Opuscules Physiques. 
                       OF  SLEEP.                     I8ii

circulation,  are exactly and unalterably correspondent.  If
the circulation through  a part be mechanically increased
or diminished, the sensibility and activity of the part will,
doubtless, be proportionally increased or diminished.  This
example occurs in hemorrhage; frequently both are caused
simultaneously,—when diarrhea renders the  surface pale
and  cold, both the blood is sent more sparingly to it, and
the action of its vessels is  diminished by the increased ac-
tivity of those of the intestines ; in ordinary sleep, the di-
minished circulation  appears the consequence, for activity
is always followed by inactivity.  Stimulate a muscle, se-
parated  from the body, it  contracts, but it soon refuses to
do so ;  after a little rest,  it again contracts  upon the re-
moval of the stimulus.   The case of the brain  is analogous;
and  when,  a/ter its daily activity, it falls asleep, the dimi-
nution of its circulation consequently ensues.
   (C)  In sleep  the action of the mind is in a high degree
suspended.    But  the  degree of suspension  is extremely
various.  In ordinary sleep  the mind is  sufficiently alert
to feel unpleasant sensations and make an effort to remove
their causes;—whether to remove  the uneasiness of  im-
peded  circulation  in the lungs by breathing, or to  draw
away the hand when  tickled.   Imagination is  often active,
and one idea associates with it another, constitutirig dream-
ing ;  but the activity of the mind is  partial, and though we
are  able occasionally  even  to  reason correctly in  our
dreams, we are not sufficiently ourselves to  discover the
incompatibility of many  circtimstances which we fancy.
In a higher degree of activity, we answer questions put to
us, although often ridiculously, as our deficiency of mental
power prevents us  from keeping our associations in a proper
train;  and we sometimes  tier, perform a regular series of
movements. 
184                    OF SLEEP.
   Between  sound sleep  and the waking state are innumer-
able degrees.   The great feature of sleep is the deficiency
of  our  active powers.   If we have any external sensation,
or if the  imagination riots on, presenting trains of images
Xp our internal senses, we reflect upon them but  weakly,
make great mistakes,  and however  well we may reason,  or
whatever  corporeal movement we  execute, the inferiority
of our  active powers is conspicuous.  That active power
is not suspended, as  Mr. Dugald Stewart maintains in his
theory of  dreaming,* the simple fact of breathing during
bleep, to  say nothing of the other motions, and the acute,
though circumscribed, reasoning which occasionally occurs
:n sleep, abundantly proves to the most superficial observer.
E'-ments of the Philosophy of the Hvmar. Mind.  Vol. 1, 
OF FOOD AND HUNGER.
1.85
SECT. XXI.
                  OF FOOD  AND  HUNGER.


   327. As sleep repairs the loss of the  animal powers,
 so food repairs that of the natural, and supplies fresh ele-
 mentary panicles  in the room  of those  which  are  con-
 stantly wasting.
   328. We are most effectually induced to procure  and
 take  food by various calls  of nature,  all  tending to the
 same  end; on one hand, by the intolerable  torment of
 hunger and thirst; and on the other, by the equally pow-
 erful allurements of appetite.
   329. Some ascribe hunger to an uneasiness arising in
 the stomach from being empty and unoccupied;  others to
 the mutual faction of its  rugae;  others not  only to the
 stimulus of its  fluids, now secreted in abundance,—of the
 saliva and  gastic  juice,—but to an acrimony which  they
 acquire when food is not taken in proper time. (A).
   330. Thirst appears referrible both to a very unpleasant
 dryness  of the  fauces, and to  the particular stimulus of
 acrid matters,  especially of salts, taken by the mouth.  It
 may be, therefore,  the  consequence of excessive absorp-
 tion in the cavity of the mouth, such as occurs when the
mother again  applies her infant  to the breast immediately
 after  it  has sucked ; or,  as  happens  not uncommonly,
when venesection  or purging have been ordered.   Violent
passions frequently induce thirst.  (B).
                         b b 
 i86               OF roOD AND UUNGKH.

   331. The  necessity  of obeying  these stimuli, is  more
 or less urgent according to age,  constitution,  and  espe-
 cially according to  habit,  and  nothing can  therefore be
 positively  affirmed  respecting   its  intensity ;  but  thus
 much is  certain,  that  an healthy adult, in whom  all  the
 calls  of nature  are  felt  in  their  usual  force,*  cannot  ab-
 stain from food a whole day without great prostration or
 strength, nor scarcely beyond  eight days  without  danger
 to his life.  (C).
   332. Although thirst  is  a violent desire, drink appears
 not  very  necessary  to life  and  health  ; for  many  warm
 blooded animals,—mice,  quails,  parrots, See. do not drink
 at all;  and some individuals of  the human  species  have
 lived in  perfect health  and strength  without  tasting li-
 quids-!
   333. It has  been  disputed whether our food, by which
 we satisfy these stimuli, is derived more advantageously
 and the more consistently with nature,  from the animal or
 vegetable kingdom.!
   334.  Some  contend  that  man  is  herbivorous, from  the
shape of his  teeth,§  the  length of his intestines,^}  the dif-
  * Consult among innumerable writers on long fasting, James Barthol.
Beccarius in  the  Commeittar. instituti Bononiens, 'I', ii. p.  i. and Flor-
J. Voltelen's memorab. apositix septennis hist. L. B 1777, 8vo.
  f See G. Baker in the Med. Transact, published by the Coll. of Physicians
in London, vol. ii. p. 265, sq.
  t J. W. Neergaard's vergleichende Anatomie und Physiologic der Ve<-
dauungsvierkzenge der Saiigethiere u?id Vbgcl.   Berlin, 1806, p. 244.
  § Gassendi's Letter to  J. Bapt. v. Helmont.  Opera. Florence, 1727,
fol. T. vi. p. 17. Al. Monro, Senr. in his Essay on Comparative Aru."r,:->
p. 17.                       }
  tf J. Wallis in the Philos. Trans. No. 269. 
OF FOOD AND HUNGER.
187
Terence between the structure  of the small  and large  in-
testines, and from the cells of the colon.  Rousseau  in-
geniously urges the circumstance  that  woman  is naturally
uniparous and provided with  two breasts.*   To these ar-
guments it may be added, that some men have ruminated,
—a  power   peculiar  to herbivorous  animals;   that  tame
vegetable feeders  are easily accustomed to animal  food,
whereas  carnivorous animals,  excepting  the dog, can
very seldom be brought to feed on vegetables.
  The arguments  of those  who,  with Helvetius,f regard
man  as carnivorous, are  derived from  the conformation
of his stomach, the shortness of the caecum, Sec.
  335.  More  careful  observation, however,  proves that
man is not destined for either kind of food  alone, but  for
both.   His teeth, particularly  the  molares,! (D)  ancl  th€
peculiar structure  of the intestines just alluded to, (E)
hold a  middle  rank between the  same  parts  in  the ferae
and   in  herbivorous  animals.    The   mode  in  which
the  condyles of the lower  jaw  are  articulated  with  the
  • Sur I'originc de Vinegalite' parmi les hommes. p. 196, sq.
  ! De rhomme. T. ii. p. 17.
  * The opinion of Brousisonet is singular.  He thinks the human mo-
lares closely resemble the teeth of herbivorous animals, and at the same
time regards the incisores and canini as allied to those of the carnivorous
tribes : and, after comparing the number of the molares with that of the
other teeth, concludes that the quantity of vegetable food  intended for
man is to the quantity of animal food as 20 to 12.
  Hut on this calculation it follew?, that infants, who  have four molares
only in each jaw, are destined to consume a larger portion of animal food
than adults, since the  proportion of the molares to the  other teeth is in
rhem as 8 to 12. 
188
OF FOOD  AND
HUNGER-
 temporal bones, demonstrates it in the most striking man-
 ner (F).
   330. As the human race  exists in  more parts  ot  the
 globe than any other kind  of  animal, we  should have
 been but ill provided for, if  we had  been destined to sub-
 sist on either description of food alone; whereas man now
 inhabits some countries  which  afford either vegetable  or
 animal food only.
   337. Man is by  far the most omniverous of  all animals,
 capable not only of feasting on  luxurious combinations
 derived from  each kingdom,  but of subsisting  with  health
 and vigour on  nearly one kind of the  most simple food.
   Thus, to mention  a  very  few instances, many at  pre-
 sent live on vegetables only, on the tubera of night-shade,
 (potatoes)  chesnuts, dates, &c.  The first families of man-
 kind  most  probably  subsisted for a  long period merely
 on fruits, roots, corn, and pulses.*
   The  nomafcle Moors have  scarcely any other food than
 gum  seneka.!
   The  inhabitants of Kamtschatka and  many other shores
scarcely any other than fish.
   The  shepherds in  the province of Caraccas in  South
America, on the banks of the  Oronoko,!  and even  the
Morlachs§ in Europe, live almost entirely on flesh.
   Some barbarous  nations devour  raw  animals.  This
cannot be denied to have  been formerly the case with  the
  * Consult my very attached friend Heyne's  Opuscula Academ. vol. i.
p. 366, sq.
  ! Adanson in the Mt/m. de I'acad. des Sc. de Paris, 1778, p. 26.
  ! Fil. Salv. Gily's Suggio di storia Americana, vol. iv. p. 120.
  § Gius. Ant. Pujati's  R'flessioni  aid vitto Pitagorico.  Feltri. 1751,
4to. 
OF FOOD AND HUNGER.
189
Samojedes,-* the Esquimaux,! and  some tribes of  South
America.!
  Other nations are no less remarkable in their c]rivk..
  The  inhabitants  of  many  intertropical  islands, espe-
cially  in the Pacific  Ocean,  can procure no sweet  water,
and instead of it drink the juice of cocoa-nuts.
  Others take only sea-water.
  Innumerable  other  facts of this kind clearly prove man
to be omnivorous-.
                         NOTES.


   (A.)  If  hunger  arise from  a sense  of vacuity  in  the
stomach, why  should it be increased by the application
of cold to the surface, the  deglutition of cold liquids,
&c. ?
   The explanation  by friction of the rugae is equally  un-
satisfactory;  because the  friction of  these, if this does
really occur, cannot  be greater  than  the friction of  the
stomach against its contents after a meal, at which time
hunger does not exist.
  * (De Klingstaedt) Me'm. sur les Samojeds et les Lappons. 1762, 8vo.
  f Curtis in the Philos. Transact, vol. lxiv. P. ii. p. 381, 383.
  i T. Winter in Hakluyt's Principal Navigations of the. English nation,
vol.  iii. p. 751. 
IPO
OF FOOD  AN'D HtJKGEK.
  Nor can the presence of the gastric juice explain the
matter; because, as every one knows, no mental sensation
arises  in any other organ which is not excrementory from
the stimulus of its .natural fluid ;  and I presume that this
is  the  stimulus alluded to,  because the mechanical  sti-
mulus  from the bulk of the gastric juice, occurs equally
from the presence of food, which does not excite hunger.
  The supposition of an  acrimony generated in the gastric
fluid, 8cc. is, as a  cause of hunger, absurd;  it would  be
unfit for its  purposes, and would be  most likely to destroy
rather than produce appetite.
  Hunger has  been attributed by some to a  sympathy of
the stomach  with a general feeling of want in the system.
But hunger is  removed immediately  that a due quantity
of food is swallowed, long before the general system can
have derived benefit from the meal.  The  circumstance
giving  rise to  this opinion is the continuance of  hunger,
although food be taken in abundance, in cases of scirrhus
pylorus and  enlarged  mesenteric glands.    Here, it  is
urged, the hunger continues, because the  body receives
no nourishment.   But,  in scirrhus of the pylorus, vomit-
ing soon follows the reception of food into the stomach,
and  therefore this  organ is  reduced to the  condition in
which  it was  previously, and  the return of hunger  is easily
explicable.   In  diseases  of the mesenteric glands, there is
in  fact no  obstruction to the  course of the chyle.   Blu-
menbach always  found  them permeable (427), and  the
continued  hunger  appears rather  a  part  of  the diseased
state of the chvlopoietic viscera.  Besides, many cases of
imperfect  nutrition, from  various causes,, occur  without
any increase of  appetite.
  If hunger  arose  from fatigue of the stomach, it should 
OF FOOD AND HUNGER.
191
 be greatest immediately after the laborious  action of  di-
 gestion, and  gradually decrease ; but  it on the contrary
 increases.
   Were irritation the cause, hunger should be  greatest
 when the stomach is filled  with food.
   On the  whole, hunger  may perhaps be regarded as a
 sensation arising from the corrugation of  the interior coat
 of the stomach.
   It is increased by cold drink,  by cold air  applied to the
 surface, by acids, bitters,  and astringents ;—all which may
 be presumed  to induce contraction of the muscular fibres
 of the  stomach, and thus corrugate  its inner coat.  It is
 diminished b*  heat and every thing which relaxes.  Again
 hunger  ceases  immediately  that  the  stomach  is  filled,
 and thus all corrugation removed.
   Being, on  this explanation, a sensation arising  from a
 local state  of the stomach,  it  will be affected not only by
 whatever affects this state, but by whatever affects also the
 sensibility  to  this  state, and  therefore  be subject to the
 common laws of sensation.  Thus, the state of the stomach
 remaining  the same, hunger may diminish from the occur-
 rence of other sensations which attract our attention  more
 forcibly, by passions of the mind, &c.; as is exactly the case
 with all other sensations, even with those  that are morbid.
 Under  strong  attention of the mind either  to pursuits  of
 intellect or passion, to delightful or painful  sensation,  all
 other  sensations cease to be  felt,  although really violent;
 and frequently, from  being unattended to,  do not recur.
 Passions, however,  may  affect  hunger,  not only by  in-
creasing or diminishing  the  sensibility to  the corrugation,
but  by  increasing or decreasing  the  corrugation,—the
cause of the sensation.
  (B.)  As  hunger appears to depend upon the local con-
dition of the stomach, &c. so  does thirst  more  evidently 
w
OF FOOD  AND HUNGER.
upon that of the fauces.  Every consideration renders  it
probable that thirst is the sensation of the dryness of the
parts in which it is seated.  Whatever produces this dry-
ness, either  by  diminishing the secretion  of the  mouth,
&c.  or by carrying off  the  fluid when secreted,  produces
thirst,  and vice  versa.  Being a sensation,  the same may-
be repeated  in  regard  to it as was observed respecting
hunger.
  (C.) Instances of fasting for a much greater length  of
time may be found in  authors, but  these  are extraordi-
nary cases.
  (D.) In carnivorous  animals,   the  incisors  are very
targe ;  and the  molares  generally of an irregular wedge
form, those of the lower jaw closing in those of the upper
like  scissars, and being  adapted  for lacerating.   In the
herbivorous, the  surface of the molares  is horizontal  or
oblique, adapted for grinding.
  (E.) As the food of herbivorous animals requires more
preparation before it  becomes  the substance  of the  ani-
mal, the  stomach is  adapted to retain it  for a length  of
time.  The oesophagus  opens  nearer the  right extremity
of the  stomach,  and the pylorus nearer  the left, so that a
blind pouch is left on  either side.  In the carnivorous, the
reverse is the case, and the stomach cylindrical,  to favour
the  quick  passage  of the food.   For the same  reason, the
intestines  in the latter have generally shorter  and fewer
valvuhe conniventes;  and, in some instances, no ccecum.
  (F.) In animals which subsist on animal food, the  con-
dyles of the  lower jaw are  locked  in an elongated  glenoid
cavity, and all rotatory motion is thus prevented, as motion
upwards and downwards is sufficient for the laceration  of
the   food.  In vegetable  feeders the joint is shallow,  so
that a horizontal * motion  is allowed  for  grinding  the
food. 
OF MASTICATION AND  DEGLUTITION.
!93
                      SECT.  XXII.

           OF MASTICATION AND DEGLUTITION.

   338. The lower jaw  is the chief organ of mastication,
and is supplied as well  as the upper with three orders of
teeth.
   With incisores,  generally* scalpriform for the purpose
of biting  off small pieces,  and not placed  in  the lowef
jaw,  as  in  other  mammalia,  more or less horizontally,
but erect—one of the distinctive  characters of  the  hu-
man race.
   With strong conical canine  teeth,  by which we divide
hard substances,  and which in man neither project beyond
the rest, nor are  placed  alone, but lie closely and in re-
gular order with the others.
   With molares  of various  sizes, adapted  for grinding,
  * I 9ay generally : for, omitting  particular examples of their obtuse-
ness, I may remark that, in the skulls of most mummies, I have found
the crown of the incisores thick  and  obtuse.   And since the more
remarkable  for this variety have resembled  in their general figure and
appearance, the singular and never-to-be-mistaken  physiognomy of the
ancient Egyptians, observable in the idols,  sarcophagi, and images or
ancient Egypt, it is probable that this peculiar  form of the teeth, whe-
tlier owing to diet or whatever else, was peculiar to the ancient Egyp-
tians, so that  it may be regarded as a  natural  mark or even character'
istic by which true ancient mummies may be distinguished from those
of late formation.
  1  have written at large on this subject in the Philos. Trans. 1794, P. »
p. 184.
                               C c 
194        OF MASTICATION AND  DEGLUTITION.

and  differing conspicuously from those  of other mam-
malia, by possessing gibbous apices singularly obtuse.
  339. The lower jaw is  connected with the  skull by a
singular  articulation, which holds a middle rank between
arthrodia  and ginglymus,;  and being  supplied  with two
cartilaginous menisci of considerable  strength, affords  an
easy motion in every direction.
  The digaster,  assisted by the geniohyoidei  and mylo-
hvodei muscles, draws the  lower jaw down, when we open
the mouth.
  The masseters and  temporal chiefly raise it again when
we bite off" any thing, and are most powerfully contracted
when we break hard substances.
  Its lateral  motions  are  accomplished  by the  internal
and external pterygoid.
  The latter can also draw it forwards.
  340. Substances  are  retained  in the mouth and moved
and  brought under  the action  of the teeth by the buccina-
tor and the  tongue, which is very flexible and changeable
in form.  (235)
  341. During manducation, there occurs  a  flow of sa-
liva* which  is a  spumous fluid, consisting  of  a large
portion  of water united vrith  some albumen, and hold-
ing in solution a small quantity of phosphate of  lime,—■
the source of the tartar of the teeth and  salivary calculi.
From being  constantly applied to the tongue, it is insipid,
although it contains some microcosmic salt (phosphate of
ammonia), as well as muriatic  and, invariably, a small por-
tion  of oxalic acid.  It is antiseptic! and very resolvent.(A)
  * J. Barth.  Sicbold's Hlatoria Systematis Salivalis. Jen.  1797, 4to.
with plates.
  ! iVmgle, on th? Diseases of the Army.  Append, p.  stria, t. nxi
sq. Loud. 1755, 4to. 
            OF MASTICATION AND DEGLUTITION.        495

   342. The saliva flows from  three orders of conglomerate
glands,  placed laterally and  interiorally with  respect  to
the lower jaw.
   The principal  are  the parotids*  which  pour forth the
saliva behind the  middle molares of the upper jaw, through
the Stenonian ducts.!                 •
   The submaxillary,] through the Whartonian.§
   The sublingual,^—the  smallest, through the numerous
Rivinian.**
   343. The excretion of  saliva, amounting, according  to
she arbitrary statement of Nuck,!! t0 a pound in twelve
hours, is augmented by stimuli and mechanical pressure,
or, if the expression may be allowed, emulsion.
   The latter cause, greatly favoured by the situation of the
parotids at the articulation of the jaws, occurs when we
chew hard substances, which thus become softened.
   The former occurs when acrid substances are taken into
the mouth,  which are thus properly diluted;  or arises from
imagination, (288) as when  the mouth waters  during the
desire for food,
   344. The mucus of the  labial and buccal glands|! and
of the tongue,  as well  as the  moisture which transudes
from the soft parts of the mouth,  is mixed with the saliva.
   345. This  mixture of fluids  poured upon a substance
* See De Courcelle's Icones Musculorum Capitis, Tab. i. g h.
! Stenon's Observations Anatomicx, p. 20.
% De Courcelles, 1. c. Tab. ir. 1.1.
§ Wharton's Adenographia, p. 120.
fl De Courcelle's tab. v. g. g. g.
** Rivinus De Dyspepsia. Lips. 1678, 4to.
Aug. Fr. Walther, De lingua Humana, ib. 1724, 4to
f! Nuck's Sialographia, p. 29, sq.
$* De Courcelles, 1.  c. Tab. iv. e. e e. 
196        OF MASTICATION  AND DEGLUTITION-
which we  are chewing, renders it not only a pultaceous
and  easily swallowed bolus,  but likewise  prepares it  for
further digestion and for assimilation.
  346.  The  mechanism*  of  deglutition,  although  very
complicated  and performed by the united powers of many
very  different parts, amounts to this.   The  tongue being
drawn towards  its  ra«>t, swelling and growing rigid,  re-
ceives the bolus of food upon its dorsum, which is drawn
into  a hollow  form.  The  bolus is  then*  rolled  into  the
isthmus  of the  fauces,  and caught  with  a curious  and
rather violent  effort by the infundibulum of the pharynx,
which is enlarged and  in some measure drawn forward to
receive it.  The three  constrictores! muscles of  the pha-
rynx  drive it into the oesophagus.  These motions are all
performed in very rapid succession and require but a short
space of time.
  347.  Nature has provided various contrivances for open-
ing and securing this passage.!
  Th--   '^portant motion of the tongue is regulated by the
:■■-, uyo:.U'.;:b.
  The smallest particle  of  food is prevented from entering
tue nostrils  or  eustachian  tubes,  by  means of  the  soft
palate,§  which,  as well  as  the uvula  suspended  from  its
  * Fr. Bern. Albinus, De Deglutitione. L. B. 1740, 4to.
  P. J. Sandifort's Deglutitionis Mechanismus. L. B. 1805, 4to.
  ! Eustachius. Tab. xlii. fig. 4, 6.
  Santorini, Tab. Posthum. vi. fig. 1.
  B. S. Albinus, Tab. Muscular, xii. fig. 23, 24.
  $ J. C.  Rosenmiiller's  Icones  Chirurgico-Anatomicx.  Fasc. i. Vinar.
1805, fol.
  § Littre in the Me'm. de VAcod. des Sc. de Paris, 1718, tab. xv.. 
            OF MASTICATION AND DEGLUTITION,         197

 arch, and  whose use is not clearly understood, is extended
 by muscles of its own, and closes those openings.*
   The tongue protects the  glottis, for the larnyx  at the
 moment  of deglutition is  drawn  upwards  and forwards,
 and in  a manner  concealed under the retracted root of
 the tongue  and  applied  to the latter in such a way, that
 the glottis  being also constricted  and protected by the
 epiglottis, is most securely defended  from the entrance of
 foreign substances.
   348.  Deglutition is facilitated  by  the abundance  of
 mucus which lubricates these parts, and which is afforded
 not only by the  tongue (237), but by the numerous  si-
 nuses! of  the tonsils and cryptas of the pharynx.
   349. The ctsophagus, through which the food must pass
 previously  to  entering  the  stomach,  is  a fleshy  canal,
 narrow  and strong, mobile, dilatable, very  sensible, and
 consisting of  coats  resembling, except in  thickness, the
 coats  of the other parts of the alimentary canal.!
   The external coat  is  muscular,  and possesses longitu-
 dinal and transverse fibres.
   The middle is  tendinous,  lax, more and  more cellular
 towards  each of its surfaces, by  which means it is con-
nected with the two other coats.
   The interior is lined,  like the  alimentary  tube, with
 an epithelium  analogous to cuticle, (176) and is lubricated
 by a very smooth mucus.
  * Santorini's Tab. Posthum. iv.—vi. fig. 2.—>and vir.
  B. S. Albinus' Tab. Muscular, xn. fig. 11* 27,28.
  f B. S. Albinus' Annotat. Acad. L. in. Tab. in. fig. 1, n.
  i See Matth. Van. Geuns in the Verhandelingen van de Maatscl
fe Haarlem.  T. xn. p. 9, sq.
  Jan. Bleuland's Observ. de structura tetophagi.  L. B. 1785, 4to 
uJ&         OF MASTICATION AND DEGLUTITION.
  350. This canal receives the  approaching draught or
bolus of food, contracts  upon  it,  propels  it downwards,
and, in the case  of the bolus,  stuffs it down, as it were,
till it passes the diaphragm and enters the stomach.
                     NOTE.

(A) Saliva is composed of
Water -	- 992	. 9
A peculiar animal matter	2	. 9
Mucus -	1	. 4
Alkaline Muriates	1	. 7
Lactate of Soda and animal matter	0	. 9
Pure Soda -	0	. 2
	1000	. 0
  General view of the  composition of animal fluids, by
J. Berzelius, M. D. Medico-Chirurgical Transactions* Vol.
ill. p. 242. 
OF DIGESTION'.
199
                    SECT.  XXIII.

                     OF DIGESTION".

   351.  J he stomach is the organ of digestion.   J^ exists,
what cannot be  affirmed of any other viscus, in perhaps
all animals without exception;  and, if  the importance of
parts may be estimated in this way, evidently holds  the
first rank among our organs.
   352. The  human  stomach*  resembles  a very  large
leathern bottle, is capable in  the adult of containing three
pints and upwards of water, and has two openings.
   The superior,  called cardia, at which the oesophagus,
folded and opening  obliquely,  expands  into the  stomach,
is placed at the left side of its  fundus.
   The inferior, placed  at the right and  narrower part of
the stomach,  and called pylorus,  descends somewhat into
the cavity of the duodenum.
   353. The  situation of the  stomach varies  accordingly
as it is in a state of repletion or depletion.  When empty,
it is flaccid  and  hangs into  the  cavity of  the  abdomen,
its  greater curvature inclining  downward,  while the  pv-
lorus,  being  directed upwards,  forms  by doubling,  an
angle with the duodenum.!
   When full, the anterior curvature is rolled forwards,!
  * Eustachius, tab. x. fig. 1, 2, 3.  Ruysch's Thee. Anal. if. Tab. v. fig.
1. Santorini's Tab. Posth. xi.
  ! Vesalius, De c. h. Fabrica. L. v. fig. 14, 15.
  t Id. 1. c. iig. 2. 
2QQ                  OF  DIGESTION.

so that  the  pylorus lies more in a line with the duodenum,
while the cardia, on the contray,  is  folded,  as  it were,
into an angle and closed.
  354. The  stomach is composed of four principal coats,
separated by the intervention  of  three others,  which are
merely cellular.
  The  external  is common to nearly  all  the  alimentary-
canal, and continuous Irith the omentum,  as we shall pre-
sently mention.
  Within this, and united to it by cellular membrane,  lies
the muscular coat, very remarkable, and the seat of the
extraordinary irritability (300) of the stomach.   It consists
of strata of  muscular  fibres,*  commonly divided into
three  orders, one  longitudinal and two circular, (straight
and oblique) but running in  so many directions  that  no
exact account can be given of their course.
  The third  is the chief membrane.  It is  usually termed
nervous, but improperly, as it consists of condensed mu-
cous tela,  more  lax on its surfaces,  which are united on
the one hand with the muscular and  on the other with
the internal villous coat.  It is firm and strong, and may'
be regarded as the basis of the .stomach.
  The  interior,  (besides  the epithelium  investing the
whole  alimentary canal) improperly called villous,  is ex-
tremely soft  and in a manner spongy,  porous,  and folded
into innumerable rugse,!  so  that  its surface is more ex-
tensive than that of the other coats ; it exhibits very small
cells,!  somewhat similar to those larger cells which are so
beautiful in the reticulum of ruminants.
  * Besides Haller, consult Bertinu» in the Me'm. de I'Acad, des Sc. de
Paris, 1761.
  ! Ruysch, Thes. Anat. n. Tab. v. fig. 2, 3,4.
  * See G. Fordycef on the Digestion of Food, p \2y 59,191 
OF DIGESTION.
201
   Its  internal surface  is  covered with mucus, probably
 secreted in the muciparous crypts which are very distinct
 about the pylorus.
   355.  The stomach is amply furnished with nerves* from
 each nervous  system (214), whence  arises its  great  sen-
 sibility, from which it is so readily affected by all kinds of
 stimuli, whether external, as cold, or internal, as food and
 its own fluids, or mental; whence also the  great and sur-
 prising  sympathy between  it and most  functions  of  the
 system; to which are  referrible  the  influence  of  all pas-
 sions upon the stomach,  and of the healthy condition of
 the stomach upon the tranquillity  of the mind.f
   356. The abundance and  utility of the blood-vessels of
 the  stomach are no  less  remarkable.  Its  arteries rami-
 fying  infinitely upon  the  cellular membrane and  glands,
 secrete the gastric juice,  which  would  appear to stream
 continually from the inner  surface  of the stomach.
   357. The general composition of this  fluid is analogous
to  that  of the saliva,  equally antiseptic, very resolvent,!
and capable  of again  dissolving  the milk  which  it  has
coagulated.^
  358.   Digestion is performed  principally by it.   The
  ■  Walter's Tab. Nervor. Thorac. et Abdom. tab. iv.
  ! J. H. Rahn.  Minim inter Caput et Viscera Abdominis Commfircium.
Gotting. 1771,4to.
  Dit. Vegens, De  Sympathia inter Ventriculum et  Caput.  L. B. 1784
4to.                                                        '
  Wrisberg, in the Commentat. Societ. Scientiar. Gotting. T. xvr.
  % Ed, Stevens, De Alimentarum Concoctione. Edinb. 1777, 8vo.
  Laz. Spallanzani, Dissertazioni di Fisica Animate e Vegetabile, Modena,
1780, 8vo. Vol. 1.
  § See Vcratti, in the Comment. Instituti Bononiens. Tom. vi.
                              D  d 
-02
OP DIGESTION-
food, when  properly  chewed and  subacted by the saliva,
is dissolved* by the  gastric fluid, and converted into the
pultaceous chyme, so that most kinds of ingesta lose their
specific qualities  and are  defended  from  the usual che-
mical changes to which they are liable, such as putridity,
rancidity, &c. and acquire  fresh properties preparatory to
chylification.f
  359.  This important  function is probably  assisted by
various acccessory circumstances.    Among them, some
particularly  mention the peristaltic motion, which, being
constant and  undulatory, agitates and subdues the  pulta-
ceous mass of food*!
  The existence of a true peristaltic motion in the stomach
during  health, is, however,  not quite certain; the  undu-
latory agitation of the stomach which occurs, appears in-
tended  for the purpose of  driving the  thoroughly dis-
solved  portions downwards, while  those  portions which
are not completely subacted  are repelled from the pylorus
by the antiperistaltic motion.
  360.  The other assistants commonly  enumerated,  are
the  pressure  on the stomach  from  the alternate motion
of the  abdomen,  and the  high temperature maintained in
the  stomach by the quantity of blood in the neighbouring
viscera and  blood-vessels, which at  one  time  was sup-
posed to  be of  such importance,  that  the word coction
was  synonymous with digestion.
  * Even the stomach itself when deprived of vitality  has been found
acted upon, and as it were, digested by it.  See John Hunter, on digestion
of the stomach after death.  Philos. Trans. Vol. ixu.
  ! Ign. DoelliDger.  Grundiss der Naturkkre des menschliclien Organis-
mus. p. 88.
  t Wepfer.   Cicutce Aquatic<e Hidoria  et  Noxx ,-  in  innumerable
places. 
OF DIGESTION.
   361. To  determine  the  time requisite for digestion, is
evidently impossible, if we consider how  it  must vary
according to  the  quality and quantity of the ingesta,  the
strength of the  digestive  powers, and  the more or less
complete previous mastication.
   During  health,  the  stomach  does not transmit the di-
gestible  parts of the food  before they are  converted into
a  pulp.  The difference ot  food must therefore evidently
cause  a  difference  in the  period necessary for digestion.*
It  may, however,  be  stated generally,  that  the chyme
gradually passes the pylorus between three  and six hours
after our meals. (A)
   362. The pylorus] is an annular limbus, consisting not,
like the  other rugae of  the stomach, of merely the villous,
but also of fibres  derived from the  nervous and muscu-
lar coats.  All  these united, form a cauoidal opening at
the termination of  the  stomach,  projecting into the duode-
num,  as the uterus  does  into the vagina,  and, as it were,
embraced by it.
                        NOTE.

  (A)  The  digestive  process does  not  go  on equally
through  the  whole mass of food, but takes place chiefly
when it is in contact  with the  stomach, and proceeds
gradually from the  superfices to the centre of the mass.
  * J. Walaeus, De Motu Chyli, p. 534.  L. B. 1651, 8vo.
  ! II. Palm. Levelling. Disserst. sistens Pylorum.  Uc.  Argent, 1764,
4to. Reprinted in Sandifort's Thes. Vol. \\i. 
204                  OF DIGES110N.
As soon as a portion is reduced to a semifluid and homo-
geneous consistence, it passes into the duodenum witfiout
waiting till the  same change  has  pervaded  the whole
mass.   During  digestion,  the  contents of  the  stomach
acquire an acid of a volatile nature, and on exposure to
the air, one  of a  more fixed  kind, probably the phos-
phoric.  Inquiry  into the original properties of the blood,
by W.  Prout,  M. D. Annals of Med. and Surg. Vol. 1,
p. 142. 
OF THE PANCREATIC JUICE.
205
                     SECT.  XXIV.

                OF THE PANCREATIC JUICE.

   363.   1 he chyme, after passing the pylorus, undergoes
new  and  considerable  changes in  the  duodenum,*—a
short but very remarkable portion of the intestines, before
the nutrient chyle  is separated.   To this end,  there  are
poured upon it various secreted fluids, the  most important
of which are the bile and pancreatic juice.
   364. Of these we shall treat separately, beginning with
the pancreatic fluid,  because  it is closely  allied both in
nature  and function to the saliva and  gastric juice  al-
ready mentioned.
   365.  Although it is with difficulty procured  pure from
living and healthy  animals, all  observations made in  re-
gard to  it  establish its close resemblance  to  the saliva.
At the present day, it  would scarcely be worth  while to
mention  the  erroneous hypothesis of F. Sylvius! and  hi*
followers,  R.  De   Graef,!  F.  Schuyl,§ and  others,  re-
specting its  supposed acrimony, long since ably  refuted by
the celebrated  Pechlin,^f Swammerdam,** and  Brunner,!!

  • Laur. Claussen,  De Intestini Duodeni  situ et nexu Lips.  1757,  4to.
Reprinted in Sandifort's Thes. Vol. iii.  And the same celebrated Leyden
Professor's Tabulx Intestini Duodeni. L. B.  1780, 4to.
  f De Chyli a fxcibus secretione.  L. B. 1659, 4to.
  $ Des sued Pancreatici Natura et Usu. ib. 1664, 12mo.
  § Pro Veteri Medicina, ib. 1670,  12mo.
  fl De Purgantium Medicamentorum Facultatibus, ib. 1672, 8vo.
  ** Observationum Anatomicarum  Collegii privati Amsteladamens.  P. n.
in  quibus prtecipue de  piscium pancreate ejusque succo agitur.  Ams. 1673,
12mo.
  !! Experimenla nova circa pancreas.  Amst. 1683, 8vo. 
206
ON THE PANCREATIO JUICE.
unless they afforded a salutary admonition, how fatal the
practice  of medicine may become, if not  founded  on
sound physiology.
  366. The source  of this fluid is similar to that of the
saliva.  It is the pancreas* by much  the largest conglo-
merate  gland  in the system,  excepting the  breasts,  and
greatly analogous to  the  salivary glands in every part of
its  structure, even in  the  circumstance of its  excretory
ducts, arising by extremely small radicles,  and uniting and
forming  one  common duct, denominated, from its disco-
verer, Wirsiingian.
  This  duct  penetrates the tunics of the  duodenum, and
supplies the cavity of this  intestine with a constant stilli-
cidium of pancreatic juice.
  367. The execretion of this  fluid is augmented by the
same causes which affect that of the saliva; viz. by pres-
sure and stimulus.
  By the  former it is emulged, whenever the stomach,
being in a  state of repletion, is  incumbent upon the pan-
creas.
  By the latter,  when  fresh and  crude chyme  enters the
duodenum and the bile flows through  the opening com-
mon to it and the pancreatic fluid.
  368. Its use  is to dissolve  the  chyme, especially if im-
perfectly  digested in  the  stomach ; and at  all  times, by
its  great abundance, to assimilate the chyme  more to the
nature of the fluids, and render it fitter for chylification.
* Santonin's Tab. Posth. xm. fig. 1. 
OF THE  BILE.
-X7
SECT.  XXV.
                       OF  THE BILE.


   369.  1 he bile  is  secreted by the  liver*—the most
 ponderous  and  large of  all the viscera, especially in  the
 foetus,!  m  which its  size is inversely as  the  age.  The
 high importance of this  organ is manifested,  both by its
 immense supply of blood-vessels,  and their  extraordinary
 distribution,  as well as by its  general existence.   It is not
 less  common to all  red-blooded  animals than the heart
 itself.
   370. The substance  of the liver  is peculiar, easily dis-
 tinguished at first sight from that of other viscera;  con-
sisting  of a parenchyma well  known in  colour, and deli-
 cate  in  texture,!  supplied  with  numerous nerves§ and
 lymphatics (most remarkable on the  surface) ;^[ with bili-
  * Eustachii. tab. xt. fig. S. 4.  Ruysch.  Thes. Anat. rx. tab. iv.  San-
torini.  Tab. Posth. xi.
  f J. Bleuland's Icon hepalis fxtus octimestris.  Traj. ad Rhen. 1789. 4to.
  F.  L.  B. Ebeling De  Pulmanum  cum  hepate Antagonismo.  Goett.
1806, 8vo.
  ! In which, however, Autenreith discovers two  substances ; the one
medullary and the other cortical.  Archiv. fiir die Physiol. T. vii. p.
299.
  § Walter, tab. iv.
  Tf Maur. v. Reverhorst.  De motu bilis circulari ejusque morbis, tab. i. 
208
OF THE BILE.
 ferous  ducts;  and  blood-vessels*  from which the  latter
 originate, both very numerous and in some instances very
 large, but of different descriptions,  as we shall state par-
 ticularly.
   371.  The first blood-vessel to  be noticed  is  the vena
portarum, whose dissimilarity from other  veins,  both  in
its nature  and course,  was  formerly hinted  at.(97)   Its
 trunk is formed from the combination of  most  of the vis-
 ceral veins  belonging  to the abdomen,  is supported by a
 cellular  sheath, called the  capsule of Glisson,!  and  on
 entering  the liver,  is  divided into branches which are
 subdivided  more and more  as  they penetrate into the sub-
 stance of the organ,  till they become extremely  minute
 and spread  over every part.  On this account,  Galen com-
 pared this  system to a tree whose  roots were  dispersed in
 the abdomen and its branches fixed in the  liver.!
   372.  The other kind of blood-vessels  belonging to the
 liver, are  branches of  the  hepatic artery, which  arises
 from the  cceliac, is  much  inferior to the  vena portae  in
 size  and the number of its divisions, but spreads by very
 minute  ramifications  throughout   the  substance of the
 liver.
   373.  The extreme divisions of these two vessels termi-
  Ruych's Ep. problemat. v. tab. vi.
  Werner and Feller's Descriptio vasor. lacteor. atque lymphaticor.  Fas-
cic. i. tab. hi. et iv. although Fr. Aug. Walter finds fault  with  these
plates.  Annot. Academic, p. 191, sq.
  Mascagni, tab. xvu. xviir.
  * Haller's Icones Anat. Fascic. ii. tab. nr.
  ! Glisson's Anatomia Hepatis. p. 305. sq. 1659.
  ! De Venarum  Arteriarumque  dissectione. p. 1C9. Opera. Basil.  1562
el. i. 
OF THE BILE.                   209
 nate in true veins, which unite  into large venous trunks
 running to the vena cava inferior.
   374.  These extreme divisions  are inconceivably minute,
 and collected into very small glomerules,* which deceived
 Malpighi into the belief that they were  glandular acini,
 hexagonal,  hollow, and secretory.!
   375.  From these glomerules arise the pori  biliarii,  very
 delicate ducts, secreting  the bile from the blood, and dis-
 charging it  from the liver through the common hepatic
 duct, which is formed from their  union.
   376.  It  has been disputed whether the bile is produced
 from arterial or venous blood.
   Although the former  opinion ] is countenanced by the
 analogy  of  the  other secretions  which  depend upon  arte-
 rial blood, nevertheless more accurate investigation proves
 that the  greater part, if not the whole, of the  biliary secre-
 tion, is venous.
   With  respect to arguments  derived from  analogy, the
 vena portse,  resembling  arteries in its "distribution,  may
 likewise  bear a resemblance to them  in function.  Besides,
the liver is but analogous to the lungs,  in which the great
pulmonary  vessels are destined  for the function of the
lungs, while  the  bronchial arteries  are intended for their
nourishment; and if we  are not greatly mistaken, the use
of the  hepatic  artery is  similar.   We  would, however,
by no means completely deny its  importance in the  secre-
  • Nest. Maximeow. Ambodick De Hepate.  Argent. 1775, 4to.
  ! De viscerum structura. p. ii. Lond. 1669.
  i This has lately found an advocate in Rich. Powel.   On the Bile and
iti Disease".  Lond. 1801, 8vo.
                           E e 
210
Ot THE BILE.
tion of bile,  but we must  regard it as  inconsiderable,  ad-
ventitious, and not well established (A).
  377. The  bile  flows  slowly  and  regularly  along  the
hepatic duct.   The greater portion runs constantly through
the ductus communis  choledochus  into  the  duodenum,
but some passes from the hepatic duct into the cystic duct,
and is received by the gall bladder, where  it remains for a
short period,  and acquires the name of cystic bile.*
  378.  The gall-bladder  is  an oblong sac,  nearly pyri-
form, adhering  to the concave surface of the  liver,  and
consisting of three coats.
  The  exterior,  completely covering it, derived  from the
peritonaeum.
   The middle, called nervous, as in  the  stomach, intes-
tines, and urinary bladder,  the source  of  its firmness  and
tone.
   The interior,]  somewhat like the  inner coat of the sto-
mach, (359)  containing a net work of  innumerable blood-
vessels,  abundant^ in mucous  glands,!   anc*  marked  by
  • In cows and other brutes there are peculiar nepato-cystic ducts, which
convey the bile directly from the liver to the gall-bladder.  Observ. anat.
coll.privati  Amstcl. P. 1. Ams. 1667, 12mo. p. 16, fig. 7.  Also, Perrault's
Essays de Physique. T. i. p 339, tab. ii.
  Some have inconsiderately  allowed them also in the the human sub-
ject : v. c. De Haen in  his Ratio med. cont. P. 11. p. 46, et seq. tab. x.

  Also Pitschell in his Anat. und chirurg. Anmerk.  Dresd.  1784. 8vo.
tab. i.
  Consult  among many, R. Forsten's Qucest. select, physiolog. Lugd. Ba-
tav. 1774. 4to. p. 22.
  ! Ruysch's Epist. problem, quinfa.  Tab. v. fig. j.
  t Vicq-d'Azyr, in his QSuvres. T. v. p. 343. 
OF THE BILE.
211
 rugae,*  which occasionally  exhibit  a  beautifully cancel-
 lated reticulum.
   379. Its cervix is conical, terminates in the cystic duct,
 is tortuous, and contains a few falciform valves.!
   380. The  bile  which has passed  into  the gall-bladder
 is  retained until, from the reclined or supine  posture of
 the body,  it  flows  down  from  it  spontaneously, or is
 squeezed! out by the  pressure  of the neighbouring jeju-
 num or ileum, or of the colon when distended by faeces.
   The presence of stimuli in  the duodenum may derive the
 bile in that direction.
   The great  contractility  of the  gall-bladder,  proved  by
 opening living  animals and by pathological phenomena,
 (although  it has not  true irritability (301) probably  assists
 the  discharge of  bile,  especially  when this fluid has,  by
 retention,  become veiy stimulating.
   381. For the  cystic  bile,  although very  analogous  to
 the  hepatic,  (377)  becomes more  concentrated, viscid,
 and bitter, by stagnation in the  gall-bladder;  the cause
 of  which  is, in all  probability,  the absorption of its more
 watery parts by the lymphatic vessels.^
  382.  Our attention  must now  be turned to  the  bile
itself,—a very  important fluid,  respecting  the nature  and
  • Casp. Fr. Wolff in the Act. Acad. Scient. Petropol. 1779.1. ii.
  ! Caldesi's  Osservaz. intorno alle Tartarughe.  Tab. ii. fig. 10;  but
especially Wolff, lately recommended, 1. c. P. i. tab. vi.  Also, Fr. Aug.
Walter, 1. c. tab. i.
  i Caldani's Institut Physiolog. p. 364, sq.  Patav. 1778, 8vo
  § Reverhorst, 1. c. tab. ii. fig. 4.
  Ruysch. 1. c. tab. v. fig. 4.
  Werner and Feller, 1. c. tab. ii. fig. 5.
  Mascagni, tab. xviii. 
212
OF THE BILE.
use of  which  there has  been for these thirty years mun
controversy than respecting any other fluid.
  The cystic bile being more perfect and better calculated
for examination, will supply our observations.
  383.  Bile taken  from  a fresh adult  subject, is rather
viscid,  of a brownish  green  colour,* inodorous, and  if
compared with that of brutes, scarcely bitter.
  384.  Its constituent parts obtained by chemical  analysis,
are, besides a large proportion  of  water, albumen, resin,
soda,!  united  partly with phosphoric,  sulphurous,  and
muriatic acid, a  small  portion of phosphate of lime  and
iron,  and a variable quantity of a remarkable and peculiar
yellow matter.!
  385.  The composition  of the bile  varies greatly both
from  the proportion  of its parts, particularly of the albu-
minous  and  resinous,  differing under different  circum-
stances, and also from  the addition, during morbid states,
to the biliary  secretion, of other constituents, especially of
adipocerous substances, which give  origin  to most biliary
calculi; for these  consist  either of it alone, or of it com-
bined with the yellow substance just mentioned (B).
  386.   The nature  of the  bile  is not  saponaceous  and
capable  of  effecting a  combination between  water  and
oils, as Boerhaave supposed, but which opinion the excel-
lent experiments  of Schroder,^ who was formerly of  this
  * On the variety of colour in the bile, consult Bordenave's Analyse de
la Bile, in the Me'm. Pre'scute's, &c. T. vii. p. 611. 617.
  ! Joachim Ramm De alcalina bills natura. Jen. 1786, 4to.
  J. Fr. Straehl De bilis natura.  Gotting. 1787,8vo.
  W. M. Richter's Experimenta circa bilis  naturam.   Erlang.  1788,
4to.
  * Thenard in the Me'moires de la Societe1 d'Arcueil. T. i.
  § Experimenta ad veriorem cystica bilis indolem explorandam capta. Sect, i
Getting.  1764, 4to. 
OF THE BILE.
213
.diversity,  both confirmed  and extended by other physio-
logists,*  have  disproved.   It  even  decomposes a  combi-
nation of those substances.!
  387. The important and various use of the bile in chyli-
ficatlon is self-evident.
  In the first place, it gradually precipitates the faeces, and
separates the milky chyle from the mixed and equable pul-
taceous chyme, while this is passing through the tract of the
small  intestines, after being propelled from the stomach
into the duodenum and diluted by the pancreatic juice.!
  It separates itself into two portions, the one serous, the
other resinous.   The latter combines  with the faeces,  tinges
them, and is discharged  with them ; the former is probably
mixed with the chyle and carried back to the blood.  (C)
  The bile  seems to act as a stimulus to the  peristaltic
motion^ of the intestines.
  We shall omit  other  less probable uses assigned to the
bile,  viz. of  exciting  hunger  by regurgitating  into the
stomach,—a  circumstance  which I  think can scarcely
happen during health.
  * It will be sufficient to quote a few of a large number.
  Spielman De natura bilis.  Argent.  1767, 4to.
  Ger. Gysb. ten. Haaf De bile cystica.  L. B. 1772, 4to.
  G. Chr. Utendorfer's Experim. de bile.  Argent. 1774,  4to.
  Dav. Willink's Consideratio bilis.  L. B. 1770, 8vo.
  Seb. Goldwitz  Neue Vers zu einer toahren  Physiol, der Galle. Bam-
berg. 1785, 8vo.
  ! Marlierr's  Prelect, in  Boerhavii  institut.  Vol. i. p.  463, 478,
1785.
  t Chr. L. Werner's (Praes AutenrietlO  Experimenta circa modum. quo
thymus in chylum mutatur.  Tubing. 1800, 8vo.
  § C. Fordyce On the digestion of food, p. 70. 
214
OF THE BILE.
                        NOTES.

  (A) Two instances  have occurred in London, of  the
vena  porta; running not to the liver, but immediately to
the vena cava inferior.  The bile must have been secreted
entirely from the  blood of the  hepatic artery.   One of
these is  described  by  Mr. Abernethy,* and the other is
mentioned by Mr.  Lawrence.!
  (B) Berzelius!  states, that bile contains alkali and salts
In the same proportion  as the blood;  that no resin exists
in it, but " a peculiar matter, of a bitter and afterwards
somewhat sweet taste, which possesses characters in com-
mon  with the fibrin,  the colouring matter,  and the albu-
men of the blood."   This forms with an excess of acid, a
perfectly  resinous  precipitate.  What has been considered
as albumen in the bile,  Berzelius regards as the mucus of
the gall-bladder.

       Bile contains of
          Water......
          Biliary matter    -  -  -
          Mucus of the  gall bladder
            dissolved in the bile  -
          Alkalies  and salts common
            to all secreted fluids  -
1000.0§
• Philos. Trans. Vol. 83.
! Medico-Chirurgic. Trans. Vol. 5, p. 174.
t Animal Chemistry, p. 65.
§ Med. Chirurg. Trans. Vol. 3, p. 241.
}
}
907.4
 80.0

  3.0

  9.6 
OF THE BILE.
215
  (C.)  During the precipitation of the chyle  and the de-
composition  of the  bile, a  gaseous  product is  usually
evolved, and the mass becomes neutral,  and traces of an
albuminous  principle commence,  strongest at  a  certain
distance from  the pylorus,  and gradually fainter in each
direction.   On mixing  bile with  chyme out of the  body,
a precipitation  takes place,  and  the mixture  becomes
neutral; but the formation of an  albuminous principle is
doubtful, probably  from the  want  of  the  pancreatic
fluid.*
  It is wonderful that in jaundice, when no bile is seen in
the  faeces, and Fordyce   says even  in  artificial obstruction
of the choledochus  by   ligature, nutrition continues.  Life
and  health  are  said to  continue after the removal of the
organ  next  to  be  considered,—the  spleen.  We  know
litde of the compensating resources of nature.
• Dr. Prout. Annals of Med. & Surg. Vol. 1. p. 143. 
216           OF THE FUNCTION OF THE SPLEEN.
                    SECT.  XXVI.


             OF THE FUNCTION OF THE SPLEEN.

   388.  A he Spleen* lies to  the left side of the liver, and
with it has   considerable vascular  communications; its
figure is oblong;! it  applies itself to the contiguous visce-
ra, and is liable to great varieties in point of form, num-
ber, See!
   389. Its colour is livid, its texture singular, soft, easily
lacerated, and  therefore surrounded by two  membranes,
the interior of  which is proper  to the spleen,  and the ex-
terior derived from the omentum.
   390.  The situation  and  size of the spleen  are  no  less
various  than its  figure,  and  depend upon  the  degree of
repletion of the stomach :  for when the  stomach is empty
and lax, the  spleen is  turgid;  when  the stomach is  full,
the spleen being compressed is emptied.
   It undergoes a continual but gentle and  equable motion,
depehdent upon respiration, under the chief instrument of
which—the diaphragm, it is immediately situated.
  • Ch. Drelincourt, the younger, has  carefully collected  and concisely
related whatever was known up to his time, respecting the spleen, De
lienosis, at the end of his father's  Opuscula.  Boerhaave's  edition,  p.
710. sq.
  Also Chr. Lud. Roloff  De fabrica et functions lienh.  Frf. ad  Viadr.
1750, 4to.
  ! Walter, tab. iii. G.
  Mascagni, tab. xiv. P.
  % See S.mdifort in the Naluur en  genees-kundige Bibl.  Vol. ii- p<
345, sq. 
            OF  THE  FUNCTION OF THE SPLEEN.        -17

   391. Its texture was formerly supposed to be cellular,
and compared to the corpora cavernosa of the penis.   This
opinion was  proved to be erroneous  by more  careful ex-
amination of the  human spleen,*  which consists entirely
of blood-vessels, of enormous size  in comparison with the
bulk of the organ.  They are in fact proportionably more
considerable than in any other part of the body.
   392. The  experiments of Wintringham  demonstrate
the great tenuity and strength of the coats of the splenic
artery.  It is divided into an  infinite  number of  twigs,
the  terminations of which  resemble pulpy penicilli and
give  rise  to  the splenic veins, which gradually unite into
large, loose,  and easily dilatable trunks.
   393. This  immense congeries of blood-vessels is con-
nected and supported  by a  sparing cellular parenchyma,
from which the adsorbents arise.  The trunks of these run
along the  lower surface  of the spleen  between  the two
coasts just described.!
   394. This loose structure of the spleen, easily becoming
distended  with  blood,  admirably confirms  what we  for-
merly remarked respecting the turgor of this organ, (390).
The  congestion and  slow return of the splenic blood, if
the nature of the neighbouring  organs  is also taken into
consideration,   illustrates its  peculiar properties, which
may  throw some  light  upon the function of this enigma-
tical viscus,—the source of so much  controversy.
  • Lobslein's Dissertation, nonnulla de Liene sistens.  Arg  ent. 774. 4to.
  | The singular and lather paradoxical opinions of Hewson, without
doubt, a very superior  man, respecting the functions of the  spleen,
whose lymphatic vessels he regards as excretory ducts, may be found in
bis  posthumous work entitled Experimental Inquiries.  Third edition.
London,  1777- 8vo. C. ii.  S. xlv.  sq. xcv. sq.
                            Ff 
 218        OF THE FUNCTION OF 1HE STLKEN-

   395. The splenic blood  is  very fluid,  coagulates  with
 great difficulty,  separates the  serum from the  crassamen-
 tum imperfectly,  and  is of a livid dark colour, like the
 blood of the foetus.  These circumstances clearly demonr
 strate the abundance in it of carbonaceous matter; which
 is  likewise  proved indisputably by an easy  experiment.
 Whenever we  have exposed sections of a recent spleen to
 oxygen  gas, they became of a very bright red, while the
 air losing its oxygen,  became impregnated with carbon.
   396. But  since  the spleen is the only organ of that de-
 scription quite  destitute of an excretory duct,  excepting
 its veins which run  ultimately to the liver, its function
 is probably subservient  to that  of the liver.  This opinion
 has appeared  strengthened  by the  observation, that  in
 animals  deprived  of their   spleen,—an  experiment  fre-
 quently made from the most remote period,* the cystic
 bile is sometimes found pale and inert.
   397.  At  least twenty hypotheses have been  framed re-
 specting the  use of the spleen.   Two  more  have been
 lately advanced,  both supposing a connection between the
 spleen and stomach, but the  one! regarding the  spleen  as
 a diverticulum to the blood destined to form the gastric
juice; (A)  the  other,!  supported  by excellent arguments
 and experiments, making the spleen receive a great  por-
 tion of our drink  from the   cardiac extremity of the sto-
 mach, so that these can pass through a short way, hitherto
 unknown,  from the stomach to the  spleen,  and thus  into
  * J. H. Schulze De splene canibtis excise.  Hoi. 1735, 4to.
  ! Vine. Malacarr.e in the Memorie della Soc. italiana. T. viii. P. 1. p.
233.
  A. Moreschi Dd vera e primario uso ddla milza. Milan. 1803, 8vo.
  $ Ever. Home in the Pldlos. Trans. 1808. 
•                   OF THE FUNCTION CF  THE SPLEEN.          219

        the mass of blood.  The latter hypothesis, if a few objec-
        tions were removed,*  would be  much the most plausible
        of any hitherto constructed. (B)
                          not^s.

   (A) This  opinion was  proposed a century ago, by Dr.
Stukely,   Fellow  of  the   Royal college  of   physicians,
London.!
   (B) Mr. Home,  having  passed a  ligature around the
pyloric  extremity of the stomach of  a dog, injected  into
it a solution of rhubarb ; and, on killing the animal  some
hours afterwards,  none of  the absorbents of the stomach
were  found distended,  nor could any trace  of rhubarb be
detected  in the  liver, but  evident  traces  existed  in the
spleen and the urine.
   • For instance, the size of the spleen in those warm blooded animals
 which never drink,  or  in bisulcous animals  whose spleen  adheres to
 the ruminant stomach  receiving the crude food only*  but never the
 drink, which is prevented from entering it by the well-known mecha-
 nism of a semicanal running from the oesophagus to the omasum.
  f Of the Spleen,  its description  and history, uses and  diseases, par-
 ticularly the vapors -with their remedy.  Being  a lectufe  read at the
 Royal College of Physicians, London, 1722.   By Wm. Stukely, M. D.
 C. M.L. and S. R. S. folio.  Considering the spleen to consist "entirely
 of complications and inoculations of arteries, veins, nerves,  and a  mus-
 cular net-work  of fibrillae, he supposed it propelled the blood from its
 own vessels into those of the stomach, when this organ required  a larger
 supply during digestion, p. 37.
  Dr.  Haighton {Lectures at  Guy's Hospital), and Mr. Saumarez, {N.-.j
 System of Physiology) explain  its operation in a  very different manner.
When the  stomach is full, the compression experienced by  the spleen
 impedes its circulation, and the blood makes its way the more copiously
 intp the arteries of the stomach and liver. 
■S20       OF  THE  FUNCTION OF THE  OMENTUM
                    SECT.  XXVII.


          OF  THE  FUNCTION* OF THE OMENTUM.


   .398.   I  he omentum  gastrocolicum  or  magnum,* (to
distinguish it from the  parvum or hepato-gastricum),f is
a  peculiar process of  peritonaeum,  arising immediately
from the peritonaeum of the stomach.
   399.  Although there are innumerable continuations of the
peritonaeum  in  the abdomen,  and every abdominal viscus
is so covered by  it,  that,  on opening the  abdomen, no-
thing is found destitute of that membrane;  this covering,
nevertheless, is afforded in  different ways,  which may be
reduced to classes.
   Over some the  peritonaeum is  merely extended, or it
affords  to  them only a partial covering,  as with respect to
the  kidneys,  rectum,  urinary bladder, and in some  mea-
sure to the pancreas and gall-bladder.
   To some which project into the  cavity of the abdomen,
 although adhering  to its parietes,  it  affords a covering for
the  greater part of their surface; v. c.  to the liver, spleen,
stomach, uterus, and the testes of the very young foetus.
  * Eustachius, tab. ix.
  Haller's Icones. anat. fasc. i. tab. iv. K. M. and the Appendix Colica,
which he himself investigated in 1740. ib. R.
  Rob. Steph. Henry's Descript. omenti c.icone nova.  Hafn. 1748, 4to.
  ! Eustachius, tab. x. fig. 1. G. II.
  Haller. 1. c. Q. 
        OF  THE FUNCTION OF THE OMENTUM.          221

  The  intestinal tube, with the exception of  the  rectum,
projects so much  in the cavity of  the  abdomen, that  it
is, as it were, suspended in loose processes of the perito-
naeum,  called mesentery and mesocolon : the broad liga-
ments of the uterus are similar to these.
  4O0.  The longest and most remarkable process  of peri-
tonaeum, is the omentum,—a large,  empty, delicate,  sac,
hanging from the large curvature of the stomach, extended
over  the  greater  part of the  small  intestines,  applying
itself closely to their  convolutions, and in some measure
insinuating itself into  their interstices.
  401.  Besides  the blood-vessels  seen upon the omentum,
it is  marked by fatty striae or bands,  every wher© reticu-
lated (whence the common appellation of this  membrane),
which in corpulent  persons increase  occasionally to a large
and  even dangerous  size, and by  means  of which  the
whole omentum is lubricated by an adipose halitus.
  402.  On  the latter circumstance  depends the use com-
monly ascribed to the omentum,—of lubricating the intes-
tines  and assisting their continual movements:  this  also
appears the use of  those  analogous  small  bursae which
are found*   in  such numbers  about the  rectumf   and
colon.!   The omentum  also prevents  the adhesion of tin
intestines to the peritonaeum, and the  consequent  impedi-
ment to the functions of the primaa viae.
  403.  There  is  another two-fold  office attributed  with
  * I have lately seen similar appendices on the peritonasal covering ..'
an uterus unimpregnated, but which had formerly been pregnant.
  ! Walter, tab. ii. m. m. m.
  4 Bidloo. .'luatomia hum. corpms. tab. sxxix fig-6. C.C.C.D.DD 
222        0*F THE FUXOTION OF THE OMENTUM.

great probability to the omentum ;* viz. that of facilitating
the dilatation of the visceTa to which it is contiguous,  and
of acting as a diverticulum to their blood during their state
of vacuity.
  404.  If we reflect on the singular structure of  the omen-
tum parvum or hepato-gastricum especially,  we may be in-
clined to  believe  that  there  is another   and  principal
office attaching to it, unknown at present,  and discover-
able by comparative anatomy.
  • V. Chaussier in the Me'rhoires de I'Acad, de Dijon, 1784, Semestr. i:.
p. 95. 
OF THE FUNCTION Or  THE INTESTINES.
                   SECT. XXVIII.

         OF  THE  FUNCTION OF THE INTESTINES.


   405.  1 he intestinal tubey over which the omentum is.
 extended,  and which receives the chyme  to  elaborate it
 farther (362, 363) and separate the chyle from the faeces,
 is  divided into two  principal portions,—the small and
 large  intestines, of whose  functions we shall  speak sepa-
 rately.
   406. The  small*  intestines  are  again divided  into.
 three ;  the duodenum, jejunum, and ileum,
   Thfc "first is named from its usual length.
   The second  from  generally  appearing collapsed and
 empty.
   The third from its convolutions : it is the longest of the
 three, fuller, and, as  it  were, inflated,  and sometimes
 resembling   the  large   intestines  by  the  appearance of
 bullae.
   407. The  coats of  the small intestines correspond with
those of the stomach (354).
   The external is derived from the mesentery.
 The muscular consists  of two orders  of fibres :  the one
longitudinal,  interrupted,  external, and found especially
 • Cbr. Bernh. Albinus. Specimen anat. exhibens novam tenuium hominis
ntestinor descriptionem. L. B.  1724. 8vo. 
224       OF THE FUNCTION OF  THE INTESTINES.

about  the part opposite the  mesentery; the  other,  annu-
lar and  falciform,  possessing the power of narrowing the
canal,  while the former shortens  it.   Upon  both depends
the very great and permanent irritability of  the intestines,
formerly mentioned (300).
   The  nervous coat   is  condensed  cellular  membrane,
easiry  reduced by handling,  or more particularly by infla-
tion,  into a  spumous  tela ;* in  it the  intestinal blood-
vessels run to the mesenteric!  in a beautiful  arborescent
form ;]  the intestines,  no less than the stomach,  are in-
debted to it for their tenacity and strength.
   The interior, lined by its  delicate  epithelium, and de-
serving  the name of villous  in the small  intestines  more
than in any other part of the canal,  forms, in conjunction
with the inner surface of the former coat,  here and there,
undulated ridges and  rugous plicae, which,  in dried and
inflated  intestines,  resemble  the edge of a scythe, and
are termed the  valvulae conniventes,  or Kerkringn?anae.§
   408. The villi, which are innumerable^ upon the inner
surface of the  intestines,  and whose beautiful and  minute
vascular  structure was  first carefully investigated,  though
described with  exaggeration, by Lieberkuhm,**  may be,x
  * B. S. Albinus Annotat. Acad. L. ii. tab. iv. fig. 1,2.
  f Eustachius, tab. xxvii. fig. 2. 4.
  i B. S.  Albinus Dissert, de arteriis  et  venis intestin. hominis, with
coloured plates.  L. B. 1736,  4to.  Also his  Annotat. acad. L. iii. tab.
i. ii.
  § Keikring's Spicilegium anatomicum, tab. xiv. fig. 1, 2.
  % He estimated their number, in the small intestines of an adult, to be
about 500,000.
  1' De fabrica et actions villorum intestinor.  tenuium  hominis, L.  B.
IT4$:  4to. 
          OF THE FUNCTION OF THE INTESTINES.       225

 per aps,  compared,  while  destitute  of  chyle,  to  little
 loose  pendulous bags,  internally  soft and spongy; but
 when  distended  with chyle,  they have the appearance of
 a  morel.
   409. The base of  these villi  is surrounded  by innume-
 rable  glandular follicles,  adhering  chiefly to the nervous
 coat,  and  opening  into the   intestinal canal  by a  verv
 small  orifice  through  which   they  discharge  the  mucus
 which lines the whole tract of the intestines.
   These are distinguished into three orders.   The Brun-
 nerian,  largest,   distinct,  found in most abundance in that
 part of  the duodenum which  is  contiguous to  the pylo-
 rus.*  The Peyerian,  smaller, aggregated, found  chiefly
 at the termination of the smaller intestines, about the valve
 of the colon.!   Lastly,  the  Lieberkuhnian, the smallest,
 said to be distributed in the  proportion of about eight to
 each  villus.!  The  two  former orders are so inconstant,
jhat I am inclined to consider the  view given of them in
 the plates  alluded to,  as morbid ;§ for I have more than
 once  been  unable to discover  the slightest trace of fun-
 gous  papillae  with a single pore,  in,, the  small  intestines
  J. Bleuland's Descriptio vasculorum intestinorum tenuium hominis  Ultraj.
1797. 4to.
  R. A. Hedwig's Disquisitio ampullarum LieburkUhnii, Lips. 4to.
  C. A. Rudolph's Anatomisch-physiologische Abhandlungen.  Berlin. 1802.
8vo. p. 39.
  • J. Conr. a Brunn's Glandule duodeni pancreas secundarium, Frf. 1715.
4to. fig. 1.
  ! J. Conr. Peyer De Glandulis intestinorum.  Scafhuf. 1677. 8vo. espe-
cially fig. 3.
  i Lieberkiihn. 1. c. p. 17, tab. iii.
  § The celebrated Rudolph thinks differently, 1. c p. 215, 
^26      OF  THE  FUK0TI0N  OF THE INTESTIKES

of  healthy  adults; while,  on the  contrary,  in  aphthous
subjects,  I have found nearly the whole intestinal tube
beset with  them in  infinite  numbers,  both  solitary  and
aggregated.*
  410.  As  the gastric  juice  is poured into the stomach,
so  an enteric  or intestinal fluid  is  poured into the small
intestines,  demonstrated,  among other ways,  by the com-
mon  experiment, first,  I believe, instituted  by Pechlin.!
It is  probably of a nature  similar  to the gastric liquor,
but an accurate  investigation of  it is a physiological desi-
deratum.  I can  say  nothing respecting its  quantity, but
the  estimation of Haller  is  certainly exaggerated,—at
eight pounds in the twenty-four hours*
  411.  The  intestines agree with the stomach in this par-
ticular,  that they have a similar, and indeed a more un-
questionable, or, at least,  a more lively, peristaltic action,]
which  occurs  principally when the  chymous pulp  enters
them.  This  it  agitates  by an  undulatory constriction of
different parts of the canal,  and propels  from the duode-
num  towards the large intestines.   Although the existence
of an antiperistaltic motion,  causing a retrograde  course
to  their  contents,  cannot be disproved, it  is  in  health
much weaker, and less common and  important than the
former.
   412. By these moving powers and by  these solvents
which  are  afforded  by means of secretion,  the chyme
  * These  intestinal  aphtha exactly  resemble  those tubercles, which
Sheldon (whom  we shall presently quote)  exhibits as small ampullar
full of chyle. Tab. i.
  | De purgantium medicamentor. facutiat. p. 509, tab.  iv.
  i Benj. Schwartz De vomitu et motu intestinorum. L. B. 1745, 4to.
  J. FocVix De motuperistaltico intestinorum.   Trevir.  I74Q, 4to. 
            OF THE  FUNCTION  OF THE INTESTINES.       227

 undergoes  remarkable  changes.*   In  the  jejunum  it  be-
 comes  a  more  liquid  pulp,  equally  mixed,  of a grey
colour,  and acidulous  odour :  in  the  ileum,  it begins to
separate into two parts,—into the faeces, of a pale yellowish,
brown  colour,!  and  nauseous  smell;  and  the  genuine
chyle, swimming  upon  the  former,  extracted  from  the
chyme,  separated by the  bile  from the  faeces, and des-
   * Consult the excellent observations and experiments of A. E. Ferd.
 Euimert, in  the Archiv. fur die Physiologic  T. viii. p. 145.
   ! We have formerly (387)  remarked,  that the bilious colour  of the
 faces arose from the excrementitious part of the bile.   In the jejunum,
 the bile being  undecomposed and mixed with the equable  pulp  in the
 intestines, and   consequently diffused  and  diluted, cannot  exhibit its
 true colour.  But after its separation into two parts, the excrementitious
 portion, mixed with the precipitated faces, and, as  it  were, again con-
 centrated, now  discovers  its  original  colour, and imparts  it  to the
 feces.
   C. F. Wolff  (in the Act. Petrep»Ut. 1779, P. ii.  p.  245,) entertains
 a different opinion in  regard  to the cause of the bilious  colour of the
 faces contained in the  ileum.  He conceives that an  addition of  bile
 occurs near the extremity of the jejunum, by exhaling from the  gall
 bladder and penetrating  this part  of   the intestine  and its  contents.—
 This bile differing, perhaps,  in  its nature, from  the  bile of the cho-
 ledochus,  and not being mixed with the faces as  the. latter is  with the
 chyme,  retains  its  colour through all the remaining tract of the intes-
 tines and continues pure bile.
  But, besides our being able easily to  explain why this  colour  is  not
 observable before the  decomposition of the chyme  and bile, it  is  ex-
 tremely doubtful whether, during  fife  and health,  any exhalation  can
occur from the gall bladder and penetrate the intestine.  For in subjects
recent and scarcely cold, the  intestines are but sliglitly tinctured with
bile, although they are dyed with it very  deeply and extensively after  a
lapse of some hours or days, i. e. after the  coats of the gall bladder have
lest tbeir  tone and become incapable of preventing the transudation of
 'heir content?. 
328        OF  THE FUNCTION OF THE  INTESTINES.

tined  for absorption  by  the lacteal  vessels,  as  we shall
find in the next  section (A).   At  present we shall enquire
what course is taken by the faeces.
   413.  These,  after becoming more and more  inspissated
in their long  course  through the ileum, have to overcome
the valve of the colon and pass  into the large  intestines.
To facilitate  this,  the extremity of the ileum is lubricated
very abundantly by mucus.
   414.  The  valve of  the colon*  or,  as it may deservedly
be termed after  its  discoverer,  the  valve  of  Fallopius,!
is a short  process or  continuation  of  the part of the ileum
penetrating  into the  cavity of  the large intestine,  which
  • Haller De valvula coU.  Gotting.  1742. 4to. reprinted  in his  Opcr.
minor. T. i. p. 580, sq.
  T. Mich. Roderer De valvula coll  Argent. 1768. 4to.     v
  ! The various opinions respecting the discoverer  of  this remarkable
valve are well known. Haller's Elementa,t. vii. P. 1. page  142, may be
consulted on this point.
  In the mean time, I  am certain that long before the  period at which
its discovery is in general dated, it was accurately known to that im-
mortal anatomist Gabr. Fallopius.  In our university library there is a
manuscript of Fallopius, containing,  among other things,  his anatomy
of the monkey,  in which is  an  account of  the structure and use of
the valve  of the colon,  delivered in  a  public demonstration at Padua,
Feb. 2,  1553, in the  following words :  " The use  of the  ceecum in the-
tnonkcy,  is  to  prevent the  regurgitation of the food during progression
on all fours.  This is proved by  the circumstance of -water  or air throu'n
into the rectum, reaching  the ceecum, but not passing  beyond the large
intestines.   But, if  thrown  in from above,  it passes  info them.   The
reason is  this,—at the insertion of the  ileum are two folds,  which are
compressed by inflation and  repletion, as  occurs  in  tlie  heart,  and pre-
vent  retrogression;  -wherefore,  in man,  clysters cannot  pass and  be re
jected through  the mouth,  unless  in  a  -weak and diseased state of the
intestines." 
OF THE FUNCTION OF THE INTESTINES.        229-
surrounds the former.   Its  external  lips, while  a neigh-
bouring fold of the large intestine at the same time pro-
jects considerably,  are  constituted* not  like other similar
folds,  merely of  the interior  and nervous coats, but of
fibres  from the  muscular  coat.   Hence it performs  the
double office of preventing  too great a  quantity of fasces
from  passing from the small into  the large intestines,  and
«f preventing regurgitation from the latter.
  415. The large intestines, divided like the  small into
three  parts, commence  by the coecum (which has  a ver-
miform process,  whose  use in man  is unknown)!  and
afford  a  very  ample  receptacle, in which the fajces may
be collected and retained till the period of their discharge-
arrives.
   41$. They  exceed the small intestines in thickness  and
strength, as well as in capacity.  The muscular coat has this
peculiarity,—that its longitudinal fibres, excepting at the ex-
tremity of the rectum, are collected into three bands, called
ligaments of the colon;!  a"d the intestines themselves arc
divided into a kind of prominent cells.  The inner coat  is
not so beautifully flocculent as  in the small  intestines, but
more similar to that of the stomach.
  417. Their  peristaltic motion is much  fainter than that
of the small intestines.  On the other hand, they experi-
  * A view of a recent and entire valve is exhibited by B. S. Albinus
in his Annotat. Academ. L. Iii.  tab. v. fig. 1. and overcharged by inflation
and drying, in Santorini's Posthumous Tables, xiv. fig. 12.
  ! Lieberkiihn.  De valvula coli et usu processus vermicularis.   L B
1739. 4to.
  J. Vosse De intestino cxco ejusque appendice venniformi.  Gottin°-
1749. 4to.                                                 °'
  t Eustachius. tab. x.  fig. 2. 4. 5 
260      OF  THE FUNCTION OF THE INTESTINES.

ence  to a greater degree  the  pressure of the abdominal
parietes, to  which the whole  length of the  colon is con-
tiguous.
  418. They gently propel the  fseces into  the rectum,
which thus becomes internally stimulated to discharged  its
contents.  This is  facilitated by the absence of transverse
rugae, and especially by the great quantity of mucus at
the extremity of the bowels.
  419. The  discharge  of faeces is principally effected  by
the pressure  of the abdomen downwards,  overcoming the
resistance of the os coccygis and of both sphincters, the
inner of which is a remarkable bundle of circular fibres;
and the outer,  a truly cutaneous muscle. After the ex-
cretion,  the  effort  of  the abdomen  having ceased, the
levator  ani retracts the intestine, which is again closed by
its sphincter.*
                        NOTE.

  (A.)  A  great part of the  chyle is generally formed
and  absorbed before  the  digested  mass  reaches  the
ileum.  See  Annals of Med. and Surgery, Vol. i. p. 144.
On arriving in the large intestines,  the  mass  undergoes
fresh changes,  at  present unexplained, and  is  converted
into excrement.  Here it is that  the  true  succus  entericus
must be poured forth.
  * All these parts may be seen as they exist in  each sex, in Santorini's
Fosth. Tables, xvi. and xvii. 
OF THE ABSORBENT  VESSELS.
231
                   SECT.  XXIX.

   OF THE FUNCTION OF THE  ABSORBENT  VESSELS.*

  420.  I he chyle which we left in the ileum just sepa-
rated from the faeces, must evidendy be a mixture of dif-
ferent fluids.  The proportion derived from the secretions,
—the  saliva, bile, the  gastric,  pancreatic,  and  enteric
fluids, surpasses, without  the  least doubt, that which  is
derived from the aliment, although it cannot be accurately
ascertained.   Hence  must  be obtained the solution of the
problem,—how injesta of such various kinds can  be con-
verted into the chyle—a fhiid constantly of the same ap-
pearance, homogeneous, and of an animal nature.
  421. The course of the chyle from the intestines to the
blood,  is  through a  part of the absorbent system,  which
we have hitherto only hinted  at,  but shall now speak  of
particularly.  It  is divided into  four parts,—lacteal  and
lymphatic  vessels, conglobate  glands, and the  thoracic
duct.  Each of these will now fall under consideration.
  422.  It is certain that the lacteals originate  among the
villi  of  the internal coat of the  intestines;  but whether
they  are  an immediate continuation of  these  villi,  or
merely connected with them by a cellular medium, admits
a question.  I myself have never been able to trace them
  * A very copious list of writers upon the absorbents will be found in
Sbmmering's work  De morbie vawnm absorbentium c«r^#m  fiwnani.
Francof. 179S.  8to. 
:32
OP THE ABSORBENT VESSELS.
so far as to discover  their immediate connections with the
villi,  but they appear  to arise here and there in the coats
of the  intestines, by a  conspicuous trunk, and  we  may
conjecture that they take up the chyle from  the  cellular
structure  into which  it  is first drawn by the villi.   This I
have in fact observed repeatedly in  puppies, after  making
them  swallow a solution of indigo,  according  to the cele-
brated  experiment of  Lister,*  an houf or  two  before
opening them alive.
  423.  The trunks just mentioned run some inches  along
the surface  of the  intestines,  under  the  external coat,
sometimes  meandering in an angular course,  before they
reach the mesentery.
  424.  In their  course through the mesentery they run
into the mesenteric glands,  of which there are two series.
The one,  nearer the intestines,  dispersed, small, and re-
sembling  beans in shape;  the other, nearer the recepta-
culum chyli, large, and aggregated.
  425.  Both appear  nothing more than closely-compacted
collections of lacteals, interwoven with innumerable blood-
vessels,! and retarding the  course  of the  chyle;  to  the
end,  perhaps,  that it may be  more intimately and  per-
fectly assimilated  to  an  animal nature, previously to its
entrance into the thoracic duct  and its  mixture with the
blood.
  426.  It has been inquired  whether lacteals exist also in
the large intestines, and their existence has been contended
for from the  effects  of particular  injections, nutrient,
inebriating, &c.  and  also by the  circumstance that  the
 ' PHlos. Trans. No. 143, compared with No. 275.
 f Boerhaave  and Ituysch's De fabrics glandularum opusculum. L. B
-22. 4to. p. 81. 
                OF THE  ABSOUBENT VESSELS.            2oj

 faeces,  if retained for any length of time, become hard and
 dry.   Although these  arguments  do not demonstrate the
 absorption of genuine  chyle below the  valve of  Fallopius,
 nevertheless it  is rendered probable by the visible  exist-
 ence  of an abundance  of lymphatics in the large  intes-
 tines,* having  the same structure  and function with the
 lacteals;  for these- absorb lymph  from  the intestines,!
 during the absence of chyle.
   But  the very different structure of the  internal coat of
 the large intestines  from that of the villous coat of the
 small, strongly  argues  that they are not naturally intended
 to absorb chyle.
   427.  There  is another  question more  important and
 difficult of solution,  whether  all the chyle  absorbed from
 the  small intestines, passes  through  the  thoracic  duct,
 or whether  some enters the  blood by other more  secret
 passages ?
   The  latter opinion rests upon very unstable arguments.
 Thus the assertion of  Ruysch, that the mesenteric glands
 become,  in  advanced  life,  indurated and  unfit  for con-
 tinuing their functions,  was  long since disproved; and
 affections of these  glands,  swellings, &c. are improperly
 called obstructions,!  as the glands  remain  pervious, rea-
 dily allowing a  passage  to  quicksilver.   The well-known
phenomenon of tepid  water  injected  after death into
 the mesenteric veins, passing  into the cavity of the  intes-
 tines, has little  weight  with  me in  regard  to a function
 which occurs  during life;  and much less weight can  be
  * Mascagni, Tab. xvi.
  f See Xuck's De Jnveniis.novis ep. Anatomies, p. 146, sq.
  $ V. J.Rezia's Specim. Observat. Anatomicar. et Puthz'.ogicar,  Ticini.
1784. 8vo. p. 18.
                           Hh 
234             OF  THE ABSORBENT  VESSELS

allowed to the bifurcated brass  tube  invented by Lieber
kiihn  to  prove   the  existence  of  these  passages.  The
assertion, that chyle has been seen in the mesentric veins,*
requires farther  investigation and proof;  so that I cannot
believe  that they carry any thing  more  than  blood,  \*ery
carbonised, and destined for the formation of bile.!
   428. The ultimate  trunks of the lacteals,  arising,  like
the  other  lymphatics, from the  combination  of  a great
number of  small  twigs,!  unite into the   receptaculum or
cysterna chyli,—the appellation by which the lower  and
larger part of the thoracic  or Pecojjetian duct  is  distin-
guished.
  * Werner and Feller, 1. c. p. 12, sq.
  ! There is a beautiful experiment, which seems, at fir3t sight, to favor
tbe existence of  these  secret  passages, and for which  I  am   in-
debted to the eminent L.  M.  A.  Caldani.    In a  lamb or kid, after
hearty feeding, a ligature is placed upon the vein  corresponding with
our left subclavian, and  another, particularly tight, upon the  mesen-
tery, at its origin near the lumbar vertebra;.   The lacteals  and lympha-
tics, between the ligatures, become  very evident; and likewise the lym-
phatics ascending from  the hind legs.   At  first, the lacteals between
the intestines and constricted mesentary swell, but they  soon subside
and d.sappear.
  But this singular phenomenon appears  to me not  owing so much to
any clandestine passages for the chyle, as to a retrograde motion  of the
chyle into the intestines;  the  valves,  under these circumstances,  not
offering sufficient opposition.   "Vide B. N. Gottl. Schreger's Fragnyenta
Anatomica et Physiologica.  Fasc. 1.  Lips. 1791,4to. p. 25.
  Flor. Caldani, in his Rifessioni sopra  alcuni punti di un  nuovo sistema
de' vast assorbenti, &c. Padua. 1792  8vo. p. 58.
  And his uncle,  commended  above,  L. M. A. Caldani,  in his Com-
mentary to be found in the Memorie lette nell' Acad, di Padova. 1804.
4to.
   \ Sheldon, 1. c. Tab. v. 
OF  THE  ABSORBENT VESSELS.
235
   429. This duct is* a membranous canal, slender, strong,
more  or  less tortuous,  subject to  great varieties  in  its
course and  division,!  destitute  of muscular fibre and
nerves, and  possessing  here  and there  valves.   At about
the  lowest cervical vertebra, after passing  the subclavian
vein,  it turns  back again,!  and is inserted into  it, being
furnished  with  a peculiar valve at the point of  insertion.
   430. The  motion  of  the chyle throughout  its course  is
to be ascribed to the contractility of its  containing vessels,
to their valves, and the vis-a-tergo.
   431. The use of the valve  placed at  the opening of the
thoracic duct,  is probably not  so much to  prevent  the
influx of  blood,  as to modify  the entrance of the chyle
into the vein,—to cause it to enter by drops.
   By this contrivance, such a portion of fresh  chyle cannot
have access to the blood as  would stimulate  the  cavities
of the  heart too  violently,  and be imperfectly  and diffi-
cultly  assimilated;  for  fresh chyle consists of very hete-
rogeneous  elements,  brought not  only  from the  primse
via;  by the lacteals,  but from every part of  the  body  by
the lymphatics.
  432.  These lytnphatics,§ which  constitute the third part
  * See Haller's Observations de ductu thoracico in theatro Gottingcnsi fac
ts. Gotting. 1741, 4to.
  B. S. Albinus' Tabula vasis chyliferi, L. B. 1757, large folio. Mascagni.
tab. xix.
  ! v. J. C. Bohl's viu: lacte.e, c. h. historia naturalis.  liegiom.  1741,
4to.
  Sommering in the Commentat. Soc. Scient. Gottingens, T. xiii. p. iii.
  ! v. Haller's Opera Minora. Vol. 1, Tab. xii.
  § Consult  among others already and hereafter quoted, J. F. Meckel,
De vasis lymphaticis glandulisque  conglobatis.  Berol. 1757. 4to.  And the
celebrated Al. Monro, filius, De renir lymphaticis ;al-Mlosis, ib. at  the same
time. 8vo. 
236           OF  THE ABSORBENT VESSELS.

of  the  absorbent system,  and resemble the  lacteals in
structure and function,  are much more,  and perhaps, in-
deed, universally, diffused.*  They arise principally from
the  mucous web, which  we therefore  called  the  grand
bond of connection  between the sanguiferous and absorb-
ing system  (27);  but in great numbers likewise from  the
external common integuments, from the fauces and oeso-
phagus (330), the pleura  and  peritonaeum, and from  the
thoracic and abdominal viscera.!
  433.  Their origin is  similar to that of the  lacteals in
the  intestines, so that the radicle of each lymphatic  ab-
sorbs the fluid  from the neighbouring cellular membrane,
as from its territory, and propels it onwards.
  434.  The lymphatics  have double valves,  set more or
less thickly in  different parts; they all  enter  conglobate
glands;*those which are contiguous to  each other, anas-
tomose here and there; and those  found on the  surface
of  certain  viscera,  as  the  lungs, liver,  &c.  form  a most
beautiful network.
  435.  Besides  other assistances to their functions, evi-
dent from  what has already  been said,  no inconsiderable
assistance is derived from the  combination of great strength
with thinness in their coats, by which they are  enabled to
support  a heavy column  of quicksilver.  In  the  limbs,
especially,  the  motion of  the  muscles pressing them on
every side, is highly useful  in increasing their power.
  436.  But their principal  action, by which  they take up
fluids more or less  rapidly, eagerly absorbing some, and
  * W. Hunter's Medical Commentaries, P. i. p. 5. sq.
  ! JSJascagni, Tab. i. ii. iii.
  T. Gottl. Haase, De vasis cutis et intestinorum  absorbentibus, &c. Lips.
1786, fbl. tab. i. 
OF THE ABSORBENT VESSELS.
237
absolutely rejecting others,*  depends upon the  peculiar
modification of their vitality,  and is ascribed by the very
acute Brugmans to a certain vita propria. (42)f
   437.  The far greater  part of these lymphatics terminate
in the thoracic duct;  except,  however,  those of the right
arm, the right side Of the neck,  the  right  lung,  and the
right portion of the diaphragm and liver, which terminate
in the subclavian vein of the same side.
   438.  From  the  universal existence of the lymphatics,
and especially from  the great numbers on the  surface,
capable of absorbing  fluids from without,  the  heteroge-
neous  nature of the lymph must be  obvious;  and this is
further  proved by accurately examining  it  in different
parts of a subject; v.  c.  that contained  in the hepatic
or  splenic  lymphatics is  perfectly different  from that  in
the uterine.
   439.  We will  enumerate  the principal fluids which are
continunally absorbed during  health, to say nothing  of
many different kinds  of substances  taken up during dis-
ease.   There  is,  besides  the chyle  separated from the
faeces in the small intestines,  the  halitus  of the cavities
properly so called,  especially that of  the fauces  and the
whole mucous web, the  fat, the more watery part of those
secreted fluids which are retained for  some time  in their
  * On this remarkable  difference consult  T. Fr.  Lucr.  Albrecht's
Commentatio (honoured with the  Royal Prize)  in qua propomtur  re-
sensus eorum  alimentor.  et medicaminum  quibus sive  tubo  alimentario
sint ingesta,  sive communibus  corporis integumentis  appticata,  ingres-
sus  in systema vasor.  sanguifer. aut concessus a natura, aut negatus sit.
Gotting.  1806, 4to.
  f Conr. Ger.  Ontyd. (Praesidente Seb. Just. Brugmans) De Causa ab-
soiptionis per vasa lymphatica.  Lug. Bat. 1795. 8vo. p. 45. 
238             OF THE ABSORBENT VESSELS.

ducts, v. c.  of the milk,  semen, bile, &c. and not a small
portion of the fluids in contact with the surface.*
  440. The solids,  after  performing their purpose in the
economy,  insensibly melt  away and are  absorbed,  as  is
proved by the absorption of the greater part of the thymus
gland during infancy, of the roots of the first teeth,  and of
the  alveoli  after the second  teeth  have  fallen out.   The
constant  change of  the  whole osseous  system, arising
from  the  insensible  renovation  of the  bony matter,  of
which we  have  treated elsewhere  professedly,!  may also
be adduced.
  441. It is therefore evident,  since so great a variety of
matter is  absorbed,  and at the same  time nothing crude
or imporper  allowed to enter the  blood, that  there is a
necessity for  some peculiar  medium  for previously sub-
acting and assimilating the various substances.
  442. It appears to be  the chief office of the  conglobate
glands,  which constitute  the last part  of  the  absorbent
system,  to prevent  the ill effects,  upon the  heart,  of the
improper  admixture of crude fluid!  with the  blood,  by
  * Consult among  others, Valer.  Lud.  Brera's  Anatripsologia, fourth
edition. Par. 1799.  11 vols. 8vo. A. J. Chrestien, De la methode iatro-
liptice. Montpell. 1803. 8vo.
  ! Decade 1. of my collection of the crania of different nations, p. 27.
  \ If we consider the winding  course which nature has provided  for
the purpose of changing and assimilating the absorbed fluids previously
to their admixture with the blood; and, on the other hand, the dreadful
symptoms, such as palpitation, convulsions,  &c. which ensue  upon the
artificial infusion of a minute portion of any mild  fluid  into the blood,
we shall be thoroughly convinced that no  absorption of heterogeneous
fluid takes place by  the veins, excepting that of the blood itself (v. c. in
the erection  of some parts,  in the placenta, &c.) and  that those absorp-
tions which Haller endeavours to prove to be accomplished by the veins,
do really take place by means of the lymphatic system.  De c. h. Funct,
V.i. p. 281 & seq. 
             OF  THE ABSORBENT  VESSELS.            239

assimilating the various fluids, particularly those absorbed
by the skin, more and more to an  animal nature,  by re-
tarding their  motion, and  perhaps  also by superadding to
them some fresh secreted fluid.(A)
  443. As to the rest of those  glands dispersed  generally
through the body,  and aggregated  here and there,  as in
the groin and axillae, they are perfectly similar to those
found in the mesentery,  consisting,  like them,  in a great
measure,  of convoluted absorbent vessels,  supplied with
an immense number of blood vessels,  and  liable to the
same diseases.*
                        NOTE.

  (A) Although some albumen is discovered  actually in
the duodenum,  and  some  fibrin in the first  lacteals, the
chyle is found to contain more and more of these substances,
in proportion  to its  progress towards the left  subclavian
vein.  The chyle contains a certain fatty matter, which is
considered as incipient albumen, and in proportion as this
decreases,  does the  quantity of fibrin and  albumen  in-
crease.  Annals of Med. and Surgery.  Vol.  i. p. 144.
* Nuck's Adenographia Curiosa.  L. B. 1696, 8vo. 
240
OF SANGUIFICATION.
                    SECT.  XXX.


                  OF SANGUIFICATION".

  444.  1 here is scarcely occasion  to  remark  that  wc
employ the  term Sanguification to denote the assimilation
of the chyle to the blood,  and the  successive reparation,
by means of the former,  of the  successive loss  sustained
by the latter.
  445. The  division of all our  fluids into three classes
(45), crude, sanguineous and secreted, turns upon this; that
the middle  class  contains  the stream of the vital fluid it-
self, from which the numerous secreted fluids are perpe-
tually withdrawn,  and to  which,  on the other hand, there
is a constant afflux of  chyle  and lymph from the absorb-
ent system.
  446. But since the blood is a peculiar fluid, sui generis,
without its fellow in nature, various assistances and media
are evidently requisite to  subact and assimilate the he-
terogeneous  and  foreign  fluids which pass  to  it from the
thoracic duct.
  447. This is, in the  first  place, especially in the mesen-
teric and other conglobate glands, favoured by those wind-
ings,  mentioned formerly, of the lacteals and lymphatics,
which are, at the same time, gradually more impregnated,
as it were,  with an animal nature.
  448. We  must also take into consideration, that a great
part of the lymph which enters the left subclavian after hs 
OF SANGUIFICATION.
241
admixture  with the intestinal chyle in  the thoracic duct,
has  been derived  from the substance  of the  viscera and
other soft parts, formerly secreted from  the  blood,  and,
therefore,  already  imbued  with  an animal nature, and
easily,  without doubt, again  miscible  with the  mass  of
blood, to which it does but return.
  449.  Something  is  contributed by the slow  and almost
stillatitious manner  in which* the  chyle  drops  into  the
blood through  the last valve of the thoracic  duct, these
very minute portions  becoming  the more intimately com-
bined with the  blood.
  450.  The heart,  too, by means of the remarkable papil-
lary muscles of the ventricles,  agitates and  mingles the
blood just impregnated with fresh chyle.
  451.  The  great  importance of the lungs  which receive
the blood immediately after its addition of fresh chyle, and
also of  respiration, in the business of assimilation,*  will be
evident on  considering the extraordinary  vascularity of
those organs (14), and their constant and regular motion.
  452.  The remaining  part of sanguification is  accom-
plished by the general circulation and the  powers which
assist it, particularly by muscular motion, &c.
  453.   Although  so  many means are provided for the
combination of the chyle with the blood, and  although the
constituents of the chyle  somewhat resemble  those of this
fluid;  nevertheless,  it is commonly asserted, that many
hours are required for the  complete change of the colour
  • Especially, according to the opinion of Cuvier, in  the conversion
of the chyle into the lymphatic or fibrous part of the blood.  L-o.ons d'
Anatomic Compare'e.  T. i. p. 91. T. iv. p. 304.  Thompson's System of
Chemistry. V. iv. p. 497.  Bostock's Work,  recommended above, in the
chapter on Rer* iration. 
242
OF SANOU1FICATIOX
of the chyle and its assimilation.  Besides other arguments
in favour of this assertion, the pathological fact is  urged,
that chyle  is frequently seen in blood drawn many hours
after digestion.  I myself have witnessed this  appearance
in  cases where the blood too  evidently  bore an inflam-
matory  disposition, to use a  common phrase; but I  am
persuaded  that  no inference  can be hence drawn, in re-
gard to  the healthy  state, which  alone  is the object of
physiology. 
OF NUTRITION.
243
SECT. XXXI.
OF NUTRITION.
   454. Besides the function of the blood  formerly in-
 vestigated—of  distributing oxygen through  the  system
 and removing carbon, its principal use is to afford nourish-
 ment to the body in general, and  to the secreting organs
 the peculiar fluids which they possess the power of deriv-
 ing from  it.  Nutrition shall be first examined.
   455. Nutrition is  the  grandest  gift  of  nature,  and
 the  common and highest  prerogative  of the  animal  and
 vegetable kingdoms, by which these, beyond  all  measure,
 surpass, even at first sight, all human machines and auto-
 mats.   Upon these no artist can bestow the faculty, not to
 say of increasing and of  coming  to perfection, but  even
 of  existing  independently   and   repairing  the incessant
 losses incurred from friction.*
  456.  By the  nutritive  faculty of the  body, its greatest
and  most admirable functions are  performed ;  by it we
grow from the first  of our  formation and arrive at man-
hood;  and  by it are remedied  the destruction and con-
  * " Nutrition, in fact, appears to be a continued generation," accord-
ing to the old observation of the very ingenious Ent.  See  his work,
already recommended, (290 note.) 
'244
OF NUTRITION.
 sumption  which incessantly occur in our system  during
 life.*
   457. Respecting the  nature of this consumption,  it has
 been greatly disputed,  whether it affects  the solids,! or
 whether,  according  to some  very acute  writers,!  these,
 when  once  formed  and perfected, remain invariably en-
 tire.
   458. There  can be no. doubt that some of the  similar
 solids,  v. c. the  epidermis and  nails,  are gradually de-
 stroyed and renewed; and the same is proved respecting
 even the bones by  the  well known  experiment  of  dying
 them with  madder  root;  (A)  and by  the frequently re-
 markable attenuation of the flat bones, especially of the
 skull, from defective nutrition in old age.§
   459.  If  I am not  mistaken,  those solid parts  undergo
 this successive change, which  possess  the  reproductive
power,—an extraordinary  faculty, by which  not only the
 natural loss of particles, but even  the  accidental removal
 of  considerable parts,  from external injuries,  is  repaired
   *  Th. Young  De corporis humani viribus conservatricibus.  Gotting.
1796, 8vo.
  Fl. J. Van  Maanen sui ipsius humana svi ipsius Conservatrice ac medi-
catrice.  Harderv. 1801, 8vo.
  ! See  the  celebrated V. J. Bernoulli's Diss, de Nutrit.  Groning.
16G9, 4to.  He estimates the continual, though insensible, loss and repa-
ration of the  solids so high, that the whole body may be said to be des-
troyed and renewed every three years.
  ]. See J. Chr. Kemme.  Beurtheilung eines Beweises vor die immaterial!-
tfft. der seele aus der medicm.  Halle. 1776,  8vo.
  And his  Z-wcifel und erinnerungsn wider die  lehre der aerzte  von der
Erntihrung der festen theile. Ibid. 1778, 8vo.
  % Respecting this mutability of the bones, I have spoken at length in
my osteological work, ed. 2. p. 26, and elsewhere. 
OF NUTRITION.
245
and perfectly supplied, as  the bones*  and  a  few  other
parts sufficiently demonstrate.
   460. On the other hand,  I  have  been led by many ex-
periments to the conclusion, that this genuine reproductive
power appears completely bestowed upon no similar parts
which possess any other vital power besides contractility,
i. e. irritability, sensibility, or a vita propria.]
   461. In these  parts,  therefore,  whose vital  powers are
ot an higher  order, the parenchyma constituting their base,
appears  permanent,  and is liable  to this  change  only,—
that the  interstices  of  the fibres  and  parenchyma,  while
nutrition  is vigorous, are constantly  full of nutrient animal
gelatine;  but, when  nutrition  languishes, are deprived of
their gelatine, collapse, and consequently become thin.
   462. For as the plastic  lymph, the  importance of which
has  been  frequently  mentioned,  is  readily converted into
cellular membrane, so it appears to constitute the principal
material  of the  body, and, as it  were,  the animal gluten,
which is nourished by its means.
  * Consult  among others G. L. Koeler's Experimenta  circa  regcnera-
tioncm ossium.  Gotting.  1786, 8vo.
  Alex. Herm. Macdonald, De necrosi et callo.  Edinb. 1799, 8vo.
  ! That the corium is not  really reproduced,  is probable, not only
from its  perpetual cicatrices (for some contend that the  matter of those
does not continue,  but  their form only, which  is  preserved by  a per-
pctual apposition of fresh particles in the room of the decayed and ab-
sorbed),  but much more by the lines and figures which  are made upon
the  skin by the singular art of pricking it with a needle, (a process
denominated  in  the barbarous  language  of the  Otaheiteans tatooing)
and imparting to the corium a blue or red colour, as permanent as the
cicatriculx, by means  of charcoal powder,  ashes, soot, the juices of
plants, or galls j  on the  other hand, the red hue  imparted to the  bones,
by means of madder, quickly  disappears, as these  parts  undergo a con-
tinual renovation. 
246                  OF NUTRITION.
   463. During  the  growth  of the body, peculiar  powers
are  exerted, by which the lymph deposited in the  cellular
membrane by the blood vessels is properly distributed and
intimately assimilated to the  substance of each organ, &c.
This is  referrible, both to the laws  of affinity, by which
particles attract, and, as it were,  appropriate  others which
are  similar  and related to themselves;  and to  the nisus
formativus, which we shall enlarge upon hereafter, and to
which the proper  applification  of  shapeless  elementary
matter, and its  modification  to particular forms, must be
ascribed.
   464. To both these powers, we conceive, must be parti-
cularly attributed  the nutrition  of  such similar parts as
are not supplied with blood;  but are, nevertheless, at first
generated  by  a  most  powerful and infallible nisus, grow,
are  nourished,  and, if  destroyed by  accident,  are very
easily reproduced ;* such are the  nails, hairs, &c.
   465. As this appears to be the true account of nutrition
in general, so, on the other  hand, it  evidently has great
varieties of degree and kind,  especially where,  from  the
more or less lax apposition of the nutritious matter,  the
structure of the similar parts is  more or.less dense, and
the specific weight of the' whole body more  or  less con-
siderable.!   In this respect, not only individuals,  but whole
  * Zwo abhandlungen  uber die nutritionskraft welche von der  Acad.
der IViss. in St. Petersburg den preiss getheilt erhalten haben. Petersburg,
1789, 4to.
  De Grimaud  Mem.  sur la  nutrition qui a obtenu Vaceessit. ib. same
year, 4to.
  Steph. J. P. Housset,  on the same subject (in the same school) in his
Me'moires physiologiques & d'hist. natureUe.  Auxer. 1787, 8vo.  T. 1.
p.  97.
  ] J. Robertson.  On  the specific gravity of living mm, in the Philos.
Trans.  Vol. L P. i. p. 30, sq. 
OF NUTRITION.
247
nations differ from  each other.  The Jakats and Burats,
who are remarkable for the lightness of their bodies,  are a
sufficient example of this.
                        NOTE.

   (A) The redness  imparted to the  bones by  feeding
animals with madder, does  not  prove that  the  matter  of
the  bones  is  constantly changing;  because the  opinion
that the madder unites with the phosphate  of lime in the
blood, and thus reddens all the bony matter subsequently
deposited, is erroneous.  Mr. Gibson proved, by numerous
experiments, that the serum  has a stronger affinity than
the  phosphate  of lime  for madder.   The  serum  being
charged with madder,  the  phosphate of lime of the bones,
already formed, seizes the superabundant madder  and be-
comes red.   If the  madder  is  no longer given to the
animal, as  it is continually passing off with the excretions,
the stronger attraction of  the serum draws it from the
bones, and  they  re-acquire the^r whiteness.  Manchester
Memoirs, vol. i. 
243
OF THE SECRETIONS  IN GENERAL-
SECT. XXXII.
           OF  THE  SECRETIONS  IN GENERAL.


  466. J3 esides the nutritious  fluids,  others of  various
descriptions are  produced  from  the  blood by means  of
secretion, which Haller, no less than his  predecessors, with
truth and regret declared to be among  the  most  obscure
parts of physiology.*
  467. The  secreted fluids  on the one hand differ so con-
siderably among  themselves, and on the other,  have  so
many points of resemblance,  that their classification cannot
but  be   extremely  arbitrary.  If we  arrange  them  ac-
cording  to the degree of difference between them and the
blood from which they are formed, they will stand in  the
following order :
  First,  the milk, which may be in some degree considered
as chyle  reproduced, and appears formed by the most sim-
ple process from  the blood newly supplied with chyle.
   Next, the aqueous  fluids, as  they are  commonly deno-
 minated from their limpid tenuity,  although the  greater
 part differ importantly from water in the nature  of their
  * v. Fouquet on Secretion, in the Encyclopedical Lexicon of Paris*
T. xiv.
  Fr. L. Kreysig De secretieribus.  Spec. i. ii. Lips. 1794,  sq. 4to. 
             OF THE SECRETIONS IN GENERAL.          249

 constituents, and especially in the proportion of albumen :
 such are the humours of the eye, the tears, in all proba-
 bility the vapour  contained in the cellular  interstices  and
 the cavities of the  abdomen and thorax;  nearly similar",
 also, is the fluid of  the  pericardium and of the ventricles
 of the brain.
   The liquor amnii of pregnancy, and the urine remarkable
 for the peculiar nature  and mixture of its proper consti-
 tuents, are generally enumerated among these.
   The salivary fluids,  concerned in mastication, digestion,
 and chylification, appear more elaborated.
   Next  the mucous, which line the cavities of most of the
 organs  performing the  natural  and genital  functions, and
 likewise the tract of the nostrils, larynx, and trachea.
   The mucus within the eye,  and under the epidermis, i9
 nearly similar.
   In the same class may be  included the cerumen of the
 ears, the  unguent of the Meibomian glands,  and of the
joints, and, perhaps, the nameless fluid poured forth into
the vagina during the venereal  oestrum.
   The adipose are, besides  the common fat, the  medulla
of the bones and grease of the skin.
   Related to these are the secretion of the corona glandis
under the preputium, and of the external female genitals.
   The  truly serous,  or albuminous,  are the fluid of the
ovarian  vesicles  of  De  Graaf; and the liquor  of the
prostate.
  The semen virile and the bile are each sui generis.
  468. It is obvious that so  great a variety of secreted
fluids cannot be  secreted from  the  mass of blood in the
same Way, hor by similar organs. Their chief  distinction
is the simplicity or complexity of their preparation.
  469. The most  simple  mode of secretion  is diapedesis,
                          Kk 
-iCJ          OF  THE SECRETIONS IN GENERAL.

or  transudation ; which is  the  case with the  fat  and  the
bony fluid.*
  470. Secretion by glands]  is more complicated.   Such
is  considered  the  secretion even  by follicles  and cryptae
found, v. c. in some parts of  the corium,  the  fauces, and
aspera arteria,  and  denominated the most simple glands.
   Properly speaking,  the conglomerate  (as they are called
to  distinguish  them from the  lymphatic  conglobate)  are
the only true  secreting  organs; such as  the  salivary and
lachrymal  glands,  the  pancreas and breasts.   They  are
provided  with   an   excretory  duct   coming  immediately
from  the   large lobes  which  are   composed of others,
smaller, and so  intricate in their structure,  as to have been
the  source of warm disputes  in the  schools of  medicine.
  * Physiologists have given different explanations of this  mode of
secretion.  Some assert that  every fluid  is formed by passing  merely
through inorganic pores from the blood: others altogether deny  the
existence of these pores.  I think much of this is a verbal dispute.  For,
on the one hand, I  cannot imagine how  inorganic  pores can be  sup-
posed to exist in an organized body, for  we are not speaking  of the
common interstices of matter, in physics denominated pores ; and I am
persuaded that every opening in organized bodies is of an  organic na-
ture, and possesses  vital powers exactly  correspondent.  On the other
hand, these openings or pores in the coats of the vessels, are evidently
little different in function from  the  cylindrical ducts, through which
fluids are said to percolate in conglomerate glands and secreting viscera:
for this percolation depends less on the  fbrm  of the  organ than on its
vital powers.
   Vid. Schreger's Fragmenta.
   P. Lupi's Nova per poros  inorganicos secrelionum  theoria refutala, &c
Uoms, 1793, ii. Vol. 8vo.
   Kreysig's Specimen Secundum, formerly mentioned.
   » Sam. Hendy, On Glandular Secretion.  Lond. 1775,  8vo 
OF THE SECRETIONS IN
GENERAL.
251
 Malpighi*  considered  the  miliary globules,  which  are
 easily  discoverable in  most  glands,  as  acini  internally
 excavated.   Ruysch,  on the  contrary,  contended  that
 these  supposed  hollow  acini  were  nothing  more  than
 glomerules  of blood  vessels,—an opinion far  more  con-
 sistent with  microscopical observation and  the effects of
 minute injection.
   471. The structure of some secreting organs,  especially
 of the liver  and kidnies, the  latter of which  strikingly
 exhibit the  glomerules of Ruysch or  the acini  of Mal-
 pighi, are  not,  excepting  in  their  peculiar parenchyma,
 very dissimilar from this structure, and indeed throw con-
 siderable light upon the  question.   On the  outer part  of
 these, small  twigs  arise  from  the sides of the  capillary
 arteries  and  run  into vascular glomerules,  hanging like
 granules as  from stalks;  from  these arterial glomerules
 spring  very  minute  colourless secreting  vessels,  whose
 origin from  the extremities of arteries, was formerly al-
 luded  to  (92); and the  radicles of  veins  into which the
 arteries are  continued, and  which convey back  into the
 venous trunks the  remaining  blood  deprived of the se-
 creted fluid.!
   472. The  organization  of some  other secreting parts  is
 evidently peculiar, v. c. of the testes, which  are composed
 of  very long and  numerous  vessels, closely compacted,
&c.
  473. That  the different nature  of the  secreted fluids
depends not so much on the  size and external form of the
  * In works repeatedly quoted, and  also  in his Diss, de glandulis con-
globatis.  Lond. 1689, 4to.
  But consult especially his Opera Posthuma.  ib. 1697. fol. and published
likewise elsewhere.
  ! Al. Schumlansky De structa renum.  Argent. 1782, 4to. tab. ii. 
25J         OF THE SECRETIONS IN GENERA L.

secreting organs as upon their interior structure and cor-
responding vital powers,  is  rendered  probable  by  the
example  of many  of our fluids, which,  although secreted
by organs  at first  sight  very  different  from each  other,
have considerable resemblance to each  other  in nature ;
v.  c.  the  saliva  and  gastric juice.    And comparative
anatomy teaches  us,  that the  same  fluids  are  formed  by
organs very  different in  external  appearance,  in different
animals.*
   474. We shall now investigate the  causes  why par-
ticular fluids  are  found  in particular organs,—the most
difficult part of the doctrine of secretion,  and still open  to
many doubts.
   475. There can  be n*> question that  the absolute cause
of the variety of secretions is referrible to the  intimate
nature of the  secreting organ.  This  depends, in the con-
glomerate  glands  and secreting  viscera  especially, both
upon  the direction and distribution  of the secreting blood
vessels, and upon the  peculiar parenchyma of each secret-
ing organ, in  some  instances  distinguishable at first sight
from the substance of every other part (20).
   476.  It is likewise probable,  and indisputable argu-
 ments in favour of the  opinion have been continually  af-
 forded  in  the course of this  work, that  secreting organs
 have  not only a peculiar parenchyma, but a vita propria,
 viz. a singular  species of vitality distinct from  the com-
 mon  vital powers of contractility,  irritability,  and sensi-
 bility.
  * Compare, for instance, the form of the kidnies in mammalia with the
true conglomerate glands which supply their place in birds ; or the pan.
creas of warm-blooded animals with the pyloric appendices, which, al-
though varying in appearance, in different fish secrete a fluid very similar
to the pancreatic. 
OF THE SECRETIONS IN GENERAL.
253
   477. The  absorbent system seems of much  importance
in the business of secretion.  In  every secreting organ, it
absorbs and conveys  to the blood  a fluid which  is, as it
were, contaminated  by the  secretion of the part:  v.  c. a
bilious fluid  in the  liver; a  spermatic in  the  testes.
A  constant circle would, therefore, appear to exist in the
secretory system, so  that  the elements of the secretions
are incessantly carried to  the blood  from the secreting or-
gans, and when they have  returned to the organs are the
more  easily attracted by a species of affinity,  and draw
with them those parts of the blood  whose nature is re-
lated to  their own.
   478. The  blood from  which some secretions are  pro-
duced,  is endowed  with peculiar  qualities.  The bile, for
example,  is derived from blood which contains an abund-
ance of carbonaceous element.
   479.  We  omit other  assistances  afforded  to  certain
secretions ;  v. c. congestion and derivation, so  striking in
the secretion of milks, &c.
   480.  There is this difference between the different fluids
secreted by the  organs and powers now  described,—that
some pass to the place of their destination immediately,
while  others  are  deposited in receptacles, and detained
there for some  length of  time,  becoming more perfect
previously to their excretion.   The milk in its ducts,  the
urine, bile, and  semen in  their respective bladders, and
the serum contained  in  the vesicles of De   Graaf,  are
examples  of this. (A) 
254
UF THE SECRETIONS IN GENERAL.
                        NOTES.

  (A) " There are two classes of secreted fluids,* viz. the
secretions,  properly so  called, or the  fluids intended to
fulfil some ulterior purpose in the animal  economy,  and
the excretions,  which  are directly  discharged from  the
body.  The fluids of  the former class are all alkaline, and
of the latter all  acid.   The excretions are the urine,  the
perspired fluid, and the milk.   All the other fluids appear
to belong to the former class.
  " The alkaline secreted fluids may be divided  into  two
very distinct  species.  The former  of these contains  the
same quantity of water as  the  blood, so  that the change
induced by the nervous influence, seems to be confined to
that of altering the chemical  form of the albuminous  ma-
terials,*  without  affecting  their relative proportion to the
water  and other substances dissolved in the blood.   The
bile, spermatic  fluid, &c.  are  of this kind.   The  latter
species consists  of  fluids, in  which the influence of  the
nervous  system has separated a large portion of  the albu-
minous matter,  and  left  the  remaining  liquid  propor-
tionally watery.   The  saliva, the humours of the eye,  and
the effused serum of membranes, are of this species,  and
m these the quantity of  salts, and in  general also of alkali,
is the same as m the blood.
  " The influence of the chemical agent  of secretion is,
therefore, chiefly spent  upon the albuminous materials of
the blood, which seems to be the soureg of every substance
that peculiarly characterises each  secretion, each of which
  * This appellation Berzelius gives to the fibrin, albumen, and colocj-r
ipg matter of the blood 
          Or  THE SECRETIONS IN GENERAL.           255

is sui generis,  and is its principal  constituent.   All the
other parts of the secretion  seem to be rather accidental,
and  to be  found there only because they were  contained
in the blood out  of which the  secretion  was  formed.
Therefore,  in examining the  secreted  fluids,  the chief
attention  should be  paid to the peculiar' matter of the
fluid, which* varies in all.   This  matter sometimes retains
some of  the properties of albumen,  at other  tifnes, none;
and hence an acurate analysis,  shewing the quantity and
nature of this peculiar matter,  is above all to  be desired.
  "  If the several secretions- be supposed to be deprived of
their peculiar matter and the  remainders analysed, the
same residue would  be  found  from them  all, which also
would be  identical  with the  fluid separated  from the
serum after its coagulation.  Thus we  should find, first,  a
portion soluble in alcohol,  consisting of the muriates of
potash and soda,  lectate of soda,  and of  an  extractive
animal substance,  precipitable  by tannin;  and secondly,
of a portion soluble only  in water,  containing soda (which
acquires  carbonic  acid  by  evaporation, and is separable
by acetic acid and  alcohol)  and another animal substance,
not  extract, precipitable  from its solution in cold water,
both by  tannin  and  muriate  mercury.    Sometimes  a
vestige of phosphate  of soda witt also be detected.
  " The excretions are of a more compound nature. They
all contain a free acid, which is termed lactic, and in the
urine this is  mixed with the uric  acid. Urine seems to
contain only  a  single peculiar characteristic matter; but
milk has as many as three, viz.  butter, curd, and sugar of
milk, which, however,   seem to be  produced by  different
organs that mingle  their fluids in  the same receptacle.
 The perspired  fluid  appears  to have no peculiar matter,
but  to be a very watery liquid, with  hardly a  vestige of 
256
OF THE SECRETIONS IN GENERAL.
 the albumen of the blood, and, in short, is the same as the
 other  excretory  fluids would be  when deprived  of their
 peculiar matter.  If  we  suppose this matter taken away
 from  those  excretions  which  possess it,  the  remaining
 fluid will be found to have  properties very  different from
 the fluid part of the  secretions,  when equally freed from
 their peculiar matter.   That of the excretions is acid, con-
 tains earthly phosphates,  and when evaporated,  leaves  a
 much larger residue than  the fluid of the secretions.   This
 resieue is yellowish-brown,  of the consistence  of  syrup,
 with an unpleasant  sharp  saline taste  of  the salts that  it
 contains.  It reddens litmus,  is most soluble in alcohol,
 and  this- spirituous solution contains  the muriates of the
blood, together with free  lactic acid, much lactate of soda
 (the soda being the  free alkali of  the blood, neutralised
by this acid), and the extractive matter, which always ac-
 companies this neutral salt.   The part insoluble in alcohol
 contains a  distinguishable quantity  of phosphate of soda,
a little  of a similar  animal matter to that found  in the
secretions,  and also  the  earthly  phosphates which were
held in solution by the  lactic  acid,  and were precipitated
by the action of the  alcohol.  The urine  possesses  also a
number of  other substances^ which  will be specified when
describing this excretion in particular."*
  * General Views of the Composition of Animal Fluids, by J. Berzelius,
M*. D, Medico. Cfirurgic. Trens. Vol. iii. v. 234. 
OF THE FAT.
5 jT
SECT.  XXXIII.
                        OF THE  FAT.


   481. Of most of the secreted fluids, a concise and con-
 nected view of which was given in the  last section, distinct
 mention has  been made in its proper place: the rest shall
 be  described as opportunity may  permit.  Two remain,
 which cannot  be discussed  in a more proper place than
 the  present,—at the close of our inquiry into the natural
 functions.  The one,—the fat,  is a  part of the system (4);
 the other,—the urine, is excrementitious.   Each shall  be
 separately examined.
  482. The fat* is an oily fluid,  very similar in its general
 character to  vegetable oils,f  bland,  inodorous, lighter than
water; containing, besides the  two elements  common to
 water, the  oils just mentioned,  and to wax, viz. carbon
and  hydrogen, sebacic  acid,:}: whish is pretty  similar  to
the benzoic*
  * VV. Xav. Jansen's Pinguedinis Animalis  Consideratio Physiologica et
Pathologica.  Lugd. Bat. 1784, 8vo.
  ] J. D. Brandis* Comm. (rewarded with the Royal Prize) de oleor. un-
gtdnosor. natura.  Goiting. 1785, 4to. p. 13.
  t Joach. J. Hhades De ferro sangui?us hum. aliisque liqiudis animalium.
ibid. 1753, 4to. ch. 4.
  Dav. H.  Knape (Pracside Segnero) De acido pingueditiis animalis. ibid.
1754, 4to.
  Laur. Crell. Chemischcs Journal. 1778. P. i. p. 102.
                             I. 1 
259
OF THE FAT.
   483.  When secreted from the blood and  deposited in
the mucous tela, it exists in  the form of drops, divided by
the laminae of the tela, in  a  manner not  unlike that in
which the vitreous humour of the eye is contained in very
similar cells.
   484.  The relation of  fat to different parts  is various.
In the  first place, some parts, even  those  whose mucous
tela  is  extremely  soft  and delicate,  never contain fat.
Such are the palpebrae and penis.
   In very many parts, it  is  diffused indefinitely, especially
in the panniculus  adiposus,  the interstices of the muscles,
&c.
   In some few,  it  is  always found, and  appears  to be
contained in  certain  definite spaces,  and destined for  par-
ticular  purposes.   Such I consider the fat around the basis
of the heart :* and in the mons veneris, where  it forms a
peculiar and circumscribed lump.f
   485.  Its  consistence varies  in different  parts.   More
fluid in the orbit, it  is harder and  more nearly resembling
suet around the kidnies.
   486.  It is  of late formation in the foetus ;  scarcely any
trace of its  existence  is   discoverable  before  the  fifth
month after conception.
   487.  There have been controversies respecting  the mode
of its secretion.   Some, as Hunter,  contending  that  it is
  * Hence it is clear how many exceptions must be made to the assertion
of the celebrated Fourcroy,—that fat is an  oily matter, formed at the
extremities of arteries, and at the greatest distance from the centre of
motion and animal heat.  See his Philosophie  Chimique, p. 112.
  f I found it more remarkable in the body of a  female of the species
ri mi a eynomolgus, from v/hich, by means  of cold, I was  able to remove it
entire. 
OF THE FAT.
259
formed by peculiar glands; others, that it merely tran-
sudes  from the  arteries.   Besides other  arguments in fa-
vour of the latter opinion, we may urge the morbid exist-  ^
ence of  fat in parts naturally destitute of it; a fact more
explicable on the supposition of  diseased action of vessels,
than of the  preternatural  formation of glands.   Thus,  it
is occasionally formed  in  the orbits ;  a lump of hard fat
generally fills  up the  place of an extirpated testicle;  and
steotoms  have been  found  in almost every cavity of the
body.
  The  glands which  some celebrated  characters  have
contended to  secrete the  fat, are at present  imaginary.
Whatever may be the truth of this matter, the deposition
and  absorption of the fat take place with great rapidity.
  488.  The use of the fat is multifarious.
  It lubricates the solids and facilitates  their movements ;
prevents  excessive  sensibility;  and, by equally distending
the skin,  contributes to beauty.
  We pass over  the particular uses of fat in certain parts,
v. c. of the marrow of the bones.
  During health, it contributes  little or nothing to  nou-
rishment.*   The modern opinion has  more  probability,—
that  it affords  a  receptacle for  the  superfluous hydrogen,
which could not otherwise be easily evacuated.f (A)
  * P. Lyonet conjectures with probability, that insects destitute of blood
derive their chief nourishment from the fat in which they abound.  Tr.
anat. de la Chenille qui rouge le bois de Saule, p. 428, 483, et «eq. prsef p.
xiii.
  f See Fourcroy, 1. c. 
260
OF THE FA1.
                        NOTE.

   (A) The fattest person on record is, I believe, Lambert
of Leicester.  He weighed seven hundred and thirty-nine
pounds.  Excessive formation of  fat  may be strongly op-
posed by regularly taking great exercise,  little sleep,  and
little, but dry food.   See the instructive case of the Miller
of Billericay,  in the second volume of the Transactions of
the Royal College of Physicians, London.   A large  collec-
tion  of cases of  obesity will be  found  in Mr. Wadd's
Cursory Hetnaris on Corpulence. 
OF THE URINE.
261
                   SECT. XXXIV.


                     OF  THE  URINE.


   489.  Besides the nutritious (4) fluids and those which
form a part of our system, others  are superfluous and  ex-
crementitious,  commonly termed  the  excrements of  the
second digestion, and are of two orders.  The one exhaled
by perspiration, of which we  treated formerly; the other,
—the urine, streaming from the kidnies.
   450.  The kidnies* are two  viscera, situated at the upper
part of the loins  on each  side,  behind  the  peritonaeum;
rather flattened;  more  liable than  any other organs to
varieties of figure  and number ;f  suspended by the emul-
gent vessels,!; which are excessively large in proportion to
the kidnies; and imbedded  in sebaceous fat. (485.)
   491. They are  enveloped in a  membrane of their  own
which  is beautifully  vascular ; and each, especially during
infancy,  consists of eight,  or  rather more smaller kidnies,
each of which again consists, as Ferrein asserts, of seventy
or eighty  fleshy  radii, denominated by  him  pyramides
albidse.
  • 6ee Al. Schumlansky, 1. c.
  f See Ger. Blase's Renum monstrosorutn exempla, at the end of Bellini
de structura et usu renum. Ainstel. 1665, 12mo.
  £ Eustachius' tabula,  1—5, which belong to his -classical work, De re-
nibus,- bound up in this eminent man's Opusc. anatom. Yenet. 1564, 4to.
same edition, tab. xii. 
262
OF THE URINE.
   492. A  kidney, if divided horizontally,  presents two
 substances; the exterior,  called cortex; the interior, me-
 dulla.
   Each abounds in blood vessels,  but the cortical portion
 has likewise very minute colourless vessels, which secrete
 the urine ;*   the  medullary  part   contains  those  which
 carry it off.
   These secreting ducts arising from the arteries  in the
 manner formerly described, (471) are united with glome-
 rules, which adhere to the cortical part and  constitute the
 greatest proportion ot  it.    They  may  be readily  dis-
 tinguished  by their angular course from  the excreting or
 Bellinian tubes, in which they terminate.   These, pursuing
 a  strait course,  run  from  the  cortical to the  medullary
 substance,  of  which they  constitute the greatest part, and
 after having  coalesced  into fewer trunks, their  mouths
 perforate,  like a sieve,  the papilla of  the pelvis of the
 organ.f
   493.  These  papillae usually correspond in number  with
 the lobes  which  form  the  kidnies, and  they convey the
 urine  secreted in  the  colourless  vessels  of the  cortex
 and carried through the Bellinian tubes  of the medulla,
 into the infundibula, which finally  unite  into a common
pelvis.
   494.  The pelvis is continued into  the ureters,  which are
  * These secreting ducts appear to have imposed upon Ferrein as a          j
new description of vessels, which he called neuro-lymphatic, or white
tubes, and of which he imagined the whole parenchyma of the viscera
to be composed.  He affiimed that they were of such tenuity, that their
length in each kidney of an adult man was equal to 1000 orgyae, or 5          \
leucx.                                                               (
  t Eustachius. tab. xi. fig. 10.                                            ' 
OF THE URINE.
2ii
membranous canals, very sensible, lined with mucus, ex-
tremely dilatable, generally of unequal  size in the human
subject in different parts,* and inserted into the  posterior
am!  inferior surface of  the bladder in such  a way, that
they do not  immediately perforate its substance, but pass
a short distance between the muscular and nervous coats,
which at that part are rather thicker than elsewhere, and
finally open into its cavity by an  oblique mouth.  This
peculiarity of  structure  prevents  the urine from  regurgi-
tating into the  ureters from the bladder. (A)
  495. The urinary bladder,]  varying in shape  according
to age and sex, is generally capable,  in  the adult,  of con-
taining about two pounds of urine.   Its fundus,  which  in
the foetus terminates in the urachus, is covered posteriorly
by  the peritonaeum.   The other  coats correspond with
those of the  stomach.
   The muscular consists of interrupted  bands of fleshy
fibres, variously decussated, and surrounding the  bladder.^
These are usually  called  the detrusor  urinse :  the fibres
which imperfectly surround the neck  and are  inconstant
in  origin  and  figure, have received  the appellation  of
sphincter.
  The nervous chiefly imparts  tone to this membranous
viscus.
   The interior, abounding in cribriform follicles,§  is lined
with mucus, principally about the cervix.
  496. The  urine conveyed to the bladder, gradually be-
  * See Nuck's Adenographia, fig. 32, 34, 35. Leop. M. Ant. Caldani, in
the Saggi dell' accad. di Padova. T. ii. p. 2.
  ■f Duverney's Usuries anatomiques. Vol. ii. tab. i.—iv.
  $  Santorim's posthumous tables, xv.
  § Flgr. Caldani's Opus. anat. Patav. 1805,  4to. p. 5. 
264
OF  I HE
L'UINE.
 comes  unpleasant  by its  quantity,  and,  growing urgent,
 inclines us to discharge it.   For  this  purpose the  urethra
 is given,  which varies with  the  sex, and will  be farther
 considered in our account of the sexual functions.
   497.  The bladder is evacuated by the constriction of the
 sphincter being  overcome both by the action of  the detru-
 sor (495) and by the pressure of  the  abdomen.   To these
in men is  superadded  the  action  of  the acceleratores,
which force  out even the drops of urine  remaining in the
 bulb of the urethra.
   498.  The nature  of  the urine varies  infinitely*  from
 age,  season of  the year,  the length of the period since
food or drink was  taken,  the quality of the ingesta,f &c.
 The urine of an adult, recently made after a tranquil re-
pose, is generally a watery fluid  of a nidorous  odour and
of a lemon  colour,  which  qualities depend on  a peculiar
uric  substance, besides a variety of other matters}; held by
the water  in solution and differing  in  proportion in dif-
ferent persons.   There is a  remarkable quantity of phos-
phoric  acid  united  with other constituents, forming phos-
phates of soda,  ammonia, and lime.   A peculiar acid,—the
lithic or uric, is  found in the urine alone.§ (B)
  • See Ualle' in the Mem. de la Soc. de Me1 dec. Vol. iii. p. 469, sq.
  f The specific quality  of  some ingesta manifest  themselves in the
urine so suddenly,  even  while blood  drawn  from a vein discovers no
sign of their presence, that physiologists have thought that, besides the
common channels, there must be some private ways running directly
from the  alimentary canal to the kidnies.  See v. c. Grimaud Sur la
nutrition, p. 115. Darwin's Zoonomia, vol. 3. § 29.  and Home, in the
Philos. Transact. 1808.
  $ See Fr. Stromeyer's Theoret. c/iemie. p. 609.
  § Consult on the analysis of the urine, among others, Berthollet, in the
Mem. de I'Acad.  des Sc. de Paris, 1780, p. 10. 
OF THE URINE.
26.*
                          NOTES.

   (A)  Mr. Charles  Bell has  lately described two long
muscles, running from  the back of the  prostate  gland to
the  orifices of the  ureters.   Their action is not  only to
assist  in emptying  the  bladder,  but  to pull  down  the
orifices  of  the ureters, thus  assisting to preserve that obli-
quity of insertion which the  ureters lose  in  proportion as
the bladder  is  depleted.—Med.  Chirurg.  Trans. Vol. III.
  (B) The following is Berzelius' analysis of urine, in the
Med. Chirurg. Trans. Vol. III.
Water -	- 933.00
Urea.....	30.10
Sulphate of potass -	3-71
Sulphate of soda -	3.16
Phosphate of soda -	2.94
Muriate of soda ...	4.45
Phosphate of ammonia	1.65
Muriate of ammonia	1.50
  Th. Lauth (prxs. Spielmann) De analysi urinx et acido phosphoreo.  Ar-
gent. 1781, 4to.
  H. Fr. Link's Commentatio (honoured with the Royal Prize) de analysi
urin<e et origine calculi.  Gotting. 1788, 4to.
  Fourcroy, in the Annates de chimie.  T. vii. p.  180. and T. xvi. p.
113.
  C.  Fr.  Gaertner's Obserx<ata  quadam circa iirinx  naturam.  Tubing.
1796, 4to.
                            m m 
266
OF THE URINE.
Free lactic acid                        "')
Lactate of ammonia     -
Animal matter  soluble  in alcohol, and !       „
                                        >  -  17.14
  usually  accompanying the  lactates
Animal matter insoluble in alcohol  -
Urea, not separable from the preceding
Earthy  phosphates with  a trace of fluate of lime 1.00-
Uric acid.......1.00
Mucus of the bladder.....0.32
Silex   --------  0.03
1000.00 
OF THE  DIFFERENCES  OF THE SEXES
267
                     SECT. XXXV.

     OF THE  GENERAL DIFFERENCES  OF  THE SEXES.

   499.  1  he  functions  hitherto examined are  common to
both  sexes,  but  some  are  performed  very differently in
each.   The  most prominent  differences shall  be  briefly
reviewed  previously to  examining the  sexual functions,
properly so called.*
   500.  In general, each sex has  its  peculiar form ;  more
or less  striking  after birth,  but  not very obvious  in the
young  foetus :  for the genitals  of the male and female, at
this period,  are  not at  first-sight different,  on account of
  * Melch.  Sebiz, De differentiis corporis virilis et  muliebris,  Argent,
1629,  4to.
  F. Thierry E. prater genitalia sexus  inter se discrepant,  Paris,  1750,
4to.
  Dictionn. Encycloped. (Ebrodun edit.) vol. xviii.  art. Femme, and Vol.
xlii. art. Viril.
  J. Fidel  Ackermann  De  discrimine sexuum prater genitalia, Mogunt.
1788,  8vo.
  The same Writer's Historia ichnographia infantis androgyni.  Jen. 1805,
fill. p.  61, seq.
  P. Roussel.   Systeme physique et morale  de la femme, ed. 2, Paris, 1803,
8vo.
  Ad. F. Nolt Diss, sistens momenta quadam circa sexus differentiam.  Got-
ting. 1788, 8vo.
  J. Lud. Moreau de la Sarthe, Histoire naturelle de la femme, Paris, 1802,
3 vols. 8vo.
  Autenreith in the Archiv.fur die Physiol. T. vii. page 3, sq. 
~68        OF  THE DIFFERENCES OF  THE SEXES.

the  clitoris being remarkably large,*   and  the  scrotum
scarcely visible.f (A)
   501. During  infancy,  the general form is but little dif-
ferent, but  becomes  more so as age advances;  when the
round and  plump breasts,  the  general  conformation,  the
delicacy,  softness,  and  the  proportionally low  stature  of
the  female,  form a striking contrast with the sinewy and
robust body of the male.^
   502. The  relation of parts,  in well-formed females, is
somewhat different  from that in the male.   For instance,
in the female the face is  proportionally smaller;  the abdo-
minal and lumber  portion of the  trunk longer;  the hips
broader,  not  however,  if  well formed, broader than the
shoulders ;  the  buttocks larger ;  the legs in their descent
gradually approach the knees.(B)
   503. A similar  difference  is  remarkale  in the osseous
  • Langguth, Embryo, 3i mensium qua faciem externam, Viteb. 1751,
4to.
  James Parsons, Philos. Transact.  Vol. xlvii p. 143.
  Morgagni, De sedibus et causis morborum. xlviii. p. 10.
  f This I lately found Confirmed in  twin  abortions of different sexes
and of about sixteen weeks formation, in whicli,  although they were
most beautifully and correctly formed, the difference of the genitalB
was not at first discoverable. In every other respect, in  the  general
figure, physiognomy,  the dimensions  of the loins,  &c. they were per-
fectly similar.
  ]. Examine   besides  the   Vier B'ucher  von  mcnschlicher  Proportion.
Nurimb. 1528, fol. of our  great  countryman  Alb.  Diirer,  the  two
celebrated male  and  female figures painted by Titian  or  one  of his
school,  in Vesalius's Epitome suor. libror. d.c. h anatome.   Basil, 1542,
fol.
  The three delineated by that excellent Artist, Ger. Laidresse,  in Bid-
loo, tub. i. ii. iii. and Girardet's  drawings in the  Corns camplet  d'Ana-
tomie grave! par A. E. Gautier et  expiique1 par M. Jadelot.  Nantz. 1773,
fol.-max 
          OF  THE DIFFERENCES  OF THE  SEXES.        269

system.   In  females, the  bones  are,  ceteris  paribus,
smoother and rounder, the  cylindrical more  slender, and
the flat thinner; to pass over individual differences, v. c.
the very slight prominence of the frontal sinuses, the more
elliptic  edges of the alveoli, the greater narrowness of the
chest, the greater capacity  on  the contrary of the  pelvis,
the difference of the clavicles, thigh bones, &c* (C)
   504.  With  respect  to  the soft parts, the female mucous
tela is more lax and yielding,  so as to dilate more easily
during pregnancy ; the  skin  is more  delicate,  and of a
clearer white, from the quantity  of fat below it.   The  hair
of the  head is commonly longer; but other  parts, which
are covered with hair in men,  are either quite smooth  in
women, as the chest  and chin; or less  hairy, as the peri-
 nseum;  or smaller in  circumference,  as  the  pudenda;
or covered  with merely a very  delicate and soft down,  as
the arms and legs. (D)
,  505.  Among  the  particular differences  of  function,
must be mentioned  the pulse, which is, in females, caeteris
paribus, more frequent (116);  the quantity  of  blood too
passing  to  the abdomen  is greater.  The lungs, on the
other hand, are smaller, from  the greater narrowness  of
the chest, which is  however more moveable  above.  The
os hyoides is much smaller, the larynx scarcely prominent
and more contracted, whence the voice is less  grave.
   506. As to  the  animal  functions,  besides the greater
abundance of nerves in the organs of generation, the general
nervous system of females is  far more mobile, and the
propensity to  emotion stronger.  On the  other  hand, the
  • I have described these differences more fully throughout the sceleton
in my Osteological work, p. 8/, sq. ed. 2-
  Compare Soemmerrin&'s  Tabula sceleti fceminei.  Francof.  1796, fol.
with the male figure in B. S. Albinus's Tubules sceleti. tab 1. 
270       OF THE DIFFERENCES OF THE SEXES,

muscular system is weaker, and the muscles (with the ex-
ception of  the  glutei, psoae, quadrati lumborum, and  a
i'tw others)  proportionally smaller. (E)
  507. In regard to the  natural  functions, the stomach
and the appetite for food, are less ;* the  growth of the
body more  rapid; and the  periods of dentition, puberty,
and full growth, earlier.
  508. But  by  far  the greatest  difference exists  in the
genital functions, which are intended  in  man for impreg-
nating, and in  women for conceiving.  The fuller  inves-
tigation of these now remains to be prosecuted.
                        NOTES.
  (A) Sir Everard Home has  published a singular theory,
which he  supports by  extremely  ingenious  arguments.f
He contends that the sex  is  not determined at the first
formation of the individual,  but that the parts of gene*- ■
ration are originally so situated,  and  of such a nature,
that they are capable of becoming either  male  or  female
organs when  the sex is subsequently  fixed.   His  argu-
ments are  the following :  1. The Testes  and Ovaria lie
originally in  the same  situation.   2. The Clitoris is at
first of great size.   3.  When the female among Mam-
malia has  inguinal  Mammae,  so likewise has the  male;
men  also possess  breasts.   4. The Scrotum  occupies in
the male, the place occupied  in the  female by the Labia,
and is of the same structure with them.  5. The Nymphae
  * Hence genuine and indubitable cases of long abstinence from food,
have generally occurred in females, (F.)
  See, among many others, Fl. James Voltelen, Diatr. Mcmorabilem sep-
tmnis apositce  historiam exhibens. Lugd. Bat. 1777, 8vo.
  + Philos. Trans. Vol, 89. 
           OF THE DIFFERENCES  OF  THE  SEXES.        271

of the female exactly correspond to the Preputium of the
male.   6.  Twins are usually of the  same  sex,  as if the
same cause had  influenced the generative organs of each ;
when they are of different  sexes, it is a common remark
that  they  seldom  breed,  nature   probably having  been
disturbed  in  her  operations.   7.   When  among  black
cattle  twins  are produced of different sexes, that  which
appears the cow is  really an  hermaphrodite,  incapable  of
breeding,  and vulgarly termed a free martin ;—a  circum-
stance in every respect analogous to the preceding.* It may
be added,  that the round ligaments  of the female descend,
like  the two spermatic chords of the  male, to the  abdo-
minal ring, and  that marsupial  bones exist,  without any
function whatever, in the  males of some  marsupial  ani-
mals ;  the  bursa fabricii of  the hen,  and  the bifid glans
clitoridis of  the opossum,  are examples similar to these,
and  comparative anatomy  furnishes  many others.   Per-
haps  Blumenbach's  explanation  is  correct,—that  they
occur  in conformity with a general law; teleologically in
the  sex, where they are useful,  and physico-mechanically
in the other.f And this explanation  is  confirmed by the
existence in  some kinds of animals,  of parts which are of
no use to them,  but exist for useful purposes generally in
animals of that description.^:
  The  sex of the  offspring  would appear  determined by
the  female  rather  than by  the male.  Mr. Knight has
observed that individual cows, &c. however various the

  * J. Hunter's Observations on certain parts  of t/ie animal economy, p. 55.
  ■f Comparative Anatomy, Bones of the Mammalia.
  ] " The title of vestiges is given in comparative anatomy to parts with-
out use in the animal in which they  are seen, and which only shew the
uniform plan followed by nature in the formation of animals."
  An elementary summary of Physiology,  by F. Majendie, translated by a
          member of the Med. Chirurg.  Society, T. 1. p. 64. 
£72        OF THE DIFFERENCES OF THE SEXES.

males, produce one sex rather than  the  other, so that he
has with  tolerable certainty  predicted the number of male
and female  young;  while nothing  similar was  ever ob-
servable  in  regard  to bulls, rams,  &c.   Even the ex-
ternal  appearance and  the habits of animals and vegeta-
bles, he  has  found much more, and sometimes altogether,
influenced by  the female.   The quantity  of  pollen em-
ployed in the fecundation of female plants, he found of no
importance in this respect.*
  (B) The  form as well as  the texture of the  female  is
more  delicate:  her  surface  has  no  muscular  protuber-
ances, but is beautifully rounded; her  legs therefore have
no calves, but, like the arms and fingers, they gently taper ;
her  feet and  hands  are small;  her  stature  one  sixth
shorter than  that of the  male ;  her neck longer.  From
the smaller  stature and  the  greater size of the abdominal
and lumbar regions, it follows that the middle point which
lies at the pubis in the male, is situated higher in the female.
Her abdomen is more prominent and  rounded, and her
shoulders less forward and distant from the trunk.  Her
thighs are more voluminous  and distant from each other.
  (C) The  greater  capacity of the female  pelvis, which
contains  the  chief  organs of generation  and   affords  a
passage  for the child, arises from  the greater expansion
of the ossa ilei, the larger  angle of the junction of the
ossa pubis, and the  greater  concavity  and  breadth of the
os sacrum :  the os coccygis  likewise is more slender and
moveable.  The clavicles  are less bent;  the thorax  more
projecting, whence deeper, although narrower and shorter;
the sternum  shorter  and broader;  the cartilago  ensi-
formus shorter;  the  two superior  ribs  flatter.   Camper
remarks,  that if  the  male and  female forms are traced
* Phihs. Trans. 1809. 
OF THE DIFFERENCES OF THE SEXES.
273
 within two ellipses of equal dimensions, the male shoulders
 will stand without and the pelvis within, while the female
 ohoulders will remain  within and the  pelvis  without.*
 The face and brain are absolutely smaller than in men, the
 face likewise proportionally so;  yet  such  is the  relative
 size of the  cranium, that while in  the male,  the  head,
 including the teeth, is as 1 to  8 or  10, in the female it  is
 as 1 to 6, of the weight of the rest  of the sceleton.
   (D)  An  instance  is  related by Professor  Roux of a
 woman forty years of age  who had one child and whose
 breasts  were  well developed,  having  a  strong  and long
 beard :  the lobes of her ears were also covered with hair.f
 Hen birds have a far less beautiful and copious plumage
 than cocks.
   (E)  Inferior to man in reasoning powers  and corporeal
 strength, woman possesses more  sensibility of both body
 and mind,  more  tenderness,  affection,  and compassion,
 more of all  that is  endearing and  capable of soothing
 human  woes,  but less firmness of character, except  indeed
 where  affection  subsists ;—although  Varium et mutabile
 semper  fcemina, is a true  character, yet  nothing  is too'
 irksome, too  painful,  or  too perilous, for a mother,  a wife,
 or a mistress, to endure or attempt for  the object  of her
 love.
  (F)  And  beastly  gluttons  for  the same  reason  are ge-
nerally  men.   A collection of  cases of voraciousness will
be found in Professor Percy's  Memoire sur la Poliphagie.]
* MJ moire sur le beau Physique.
\ Anatome descriptive, par. Xav. Bichat. T. V
$ Journal de Medecine. Brumaire. An. xiii.
                 n n 
274
OF THE (VENITAL FUNCTION IN MAX-
                   SECT. XXXVI.


            OF THE GENITAL FUNCTION IN MAN.

  509.  1 he genital fluid is produced in the two testicles,
which hang  in  the  scrotum,  by their spermatic chords;
through  a  ring  called abdominal,  or  through, more pro-
perly,  a fissure  in  the tendon of the external  oblique
muscle  of  the  abdomen.   Besides abundant lymphatics,
three orders of vessels are found in the testes. (A)
  The spermatic artery,  which is, in  proportion  to the
fineness of  its caliber, the  longest  artery, by far,  in the
system, and usually  conveys blood to the  testicle imme-
diately from the aorta.
  The ductus deferens, which carries to the vesicula? semi-
nales the semen separated from the arterial  blood.
  The pampiniform plexus  of  veins,  which return to the
cava or renal vein the blood remaining after secretion (B).
  510. The testes are not always suspended in the  scro-
tum.   In the very young male foetus,   they are placed in
a  far  different  situation,  the  nature   and  successive
changes  of  which were first  accurately  ievestigated  by
Haller,* but have since been variously explained;  and the
causes of  this  change of situation have  given  rise  to
numerous  controversies.    I shall  derive  my account of
  * Haller's Progr. de herniis congenitis, reprinted in his opusc. patholog.
p. 311, sq. vol. iii. Opera minora. 
           OF THE GENITAL FUNCTION  IN  MAN.       275

this  subject  from the natural appearances which  I have
preserved in  a  great  number of small  embryos, dissected
by me with this view.
  511.  On opening the lower part of the  abdomen of a
young foetus, there appears m each groin,  at  the  ring of
the oblique muscles, a very narrow opening in  the peri-
tonaeum, leading downwards to  a narrow passage which
perforates  the  ring and runs to a peculiar sac, extended
beyond the abdominal cavity towards  the  scrotum, inter-
woven with cellular fibres,  and destined for  the future re-
ception of the testicle.
  512.  At the  posterior margin of this  abdominal open-
ing, there  is  sent off  another  process of peritonaeum, run-
ning  upwards,  and appearing,  in the young  foetus,  as
little  more than a longitudinal fold,  from the  base  of
which arises a small cylinder, or rather an inverted cone,
which terminates above  in a globular  sac,  containing the
testis and  epididymis,  so  that  the testis, at  first sight,
resembles a small berry resting on its  stalk, and  appears
hanging, like the liver or spleen, into the abdomen  (399).
  513.  The vessels which  afterwards constitute the sper-
matic  chord,  are  seen  running  behind the very delicate
and pellucid  peritonaeum;  the spermatic  artery and vein
descending 'along the sides of the spine,  and the vas de-
ferens passing inwards in  the loose cellular substance be-
hind  the peritonaeum towards the neck  of the  bladder.
They enter the testis in the fold of peritonaeum just men-
tioned.
  514.  After about  the middle period of pregnancy, the
testes  gradually descend and  approach the narrow  passage
before  spoken of (511),  (the fold  of peritonoeum becoming
at the same time doubled together with the cylinder) until
they lie directly over the opening of the passage. 
276        OF THE  GENITAL FUNCTION IN MAN.

  515. The  testis  being now ready for  its  descent, the
opening which was  hitherto small, becomes dilated,  so  as
to allow the  organ  to pass the abdominal ring and  pas-
sage and descend into the bulbous  sac (511); after this
occurrence, the  opening  soon becomes  strongly closed
and even unites  together,  leaving  scarcely any vestige  of
itself in infancy.
  516. In  proportion to the slowness with which the  testis
proceeded towards  the opening,  does its  transit  through
the  abdominal  passage  appear rapid,  and, as  it were,
instantaneous.   It is common  to  find the  testis in mature
foetuses either  lying  over the  peritonaeal  opening, or,
having passed this,  resting in the groin;  but I once only
met with the right testis, in  a twin foetus, at  the very
time when  it was adhering, and in a manner  strangled,  in
the middle  of the passage, being just about to enter the sac;
in this instance,  the  left testis had passed the  abdominal
canal and  was  already  in the  sac,  and the  abdominal
opening was  perfectly closed.
  517. This remarkable  passage  of the testis from the
abdomen through the groin, is limited  to no period, but
would seem  to  occur generally about the last month  of
pregnancy; not  veiy rarely,  however, the  testicles are
found in the abdomen or  the  upper portion of the  groin
at birth.   For  they  have  always another  part  of  their
course to finish, after leaving the  abdomen, viz. to de-
scend, together  with  their sac,  from the  groin  into the
scrotum.
  518. Repeated observation  demonstrates this to be the
true  course of  the testicles.   To  assign the powers and
causes  of its accomplishment   is  no  easy  matter. For I
am every day more convinced, that neither of the powers
to v/hich  it is  usually  ascribed,  viz. the action of the 
           OF THE  GENITAL FUNCTION  IN  WAN.        27.7

ere master or  diaphragm, or the mere contractility of the
cellular membrane interwoven with tendinous fibres, which
adheres to  the  cylindrical  process  of peritonaeum (512)
and is called  the Hunterian gubernaculum,  is sufficient to
explain so  singular a  movement, and least of all to ex-
plain  the transit of the  testis through the passage so  often
mentioned: but that the whole affords, if any  thing  does,
a striking illustration of a  vita  propria, without the pecu-
liar  influence  of  which,  so  remarkable  and unique a
course, similar to no other  function of the system, cannot
even be scarcely imagined (C).
   519.  The coats  of  the testes, after their descent, are
conveniently divided into common and proper.
   The  common is the scrotum,  consisting of the  skin
having a very  moderate substratum of fat and  differing
from  the rest of the integuments in  this,—that it is con-
tinually changing its appearance, being sometimes lax and
pendulous,  sometimes  (especially  during  the  venereal
orgasm and the application of cold)  constricted and rigid,
and  in the latter case, singularly  marked  by rug^e and
furrows.
   520. With respect to the coats proper to  each testis,
the dartos  lies immediately under  the  scrotum, and is  en-
dowed with  a  peculiar   and  strong contractile power,
which deceived  the celebrated Winslow, Haller,  &c. into
the belief of the presence of muscularity (D).
   521. Next  to this,  with the  intervention  however  of
much soft  cellular substance, are found three orders  of
tunicas vaginales ;* viz. an exterior common to the  testis
  * J. E. Neubauer  De tunicis vaginalibut  testis et funiculi spermatid.
Cicss. 1767, 4to.
  F. L. Eichhorn De hydrocele.  Getting. 1889, 4to. 
278         OF THE GENITAL FVNCTION IN MAN.

and spermatic chord, and to which  the cremaster muscle
adheres  by disjoined bundles of fibres ;  and two  interior,
one proper to  the chord, and one  to  the testis; the fundus
of the  latter  of  which  usually adheres  to the common
coat, but is internally moistened, like the pericardium, by
a lubricating fluid (E).
  522.  The origin of these  coats,—the  subject of so much
controversy, may, I think, be readily explained, from the
circumstances  already mentioned attending the  descent of
the testis.
  The  common  coat arises from the  descending bulbous
sac or peritonaeal process (511).
  The proper coat of the  testis, from that production  of
•he peritonaeum which, ascending from  the  cylinder  (512)
originally invests the testis.
  The  coat proper to the chord from that fold and  short
cylinder of the peritonaeum in  which the fold terminates
before it surrounds the testicle (F).
  523.  To  the body of the testis* there  adheres   very
firmly,  like the bark of a  tree, a coat called  albuginea,
through the combination of which with the internal  part
of the vaginal  coat, blood-vessels, penetrate  into the  pulpy
substance of the testis.f  This pulpy substance is entirely
composed of innumerable vessels, about a span in  length^
and convoluted into lobules,  both  conveying blood and
secreting semen,§ the latter of which is carried  through
  * Alex. Monro fil. De testibus et de scmine in variis animalibus.  Edinb,
1755, 8vo.
  ■j- B. S. Albinus. Annotat. Acad. L. ii. tab. vii. fig. 1, 2, 3.
  t Vide Grew. Museum of the Royal Society, p. 7.
  § The celebrated Sbmmerring was so successful as.to inject all the ves-
sels composing the testis, and the entire head of the epididymis with mer-
cury.  $ee his Uber die kb'rpe^l. Ve-sch. dei "legc^s vom EuropUer, p. 38- 
OF THE GENITAL FUNCTION IN MAN.          279
 the  rete vasculosum of  Haller* and  the  vasa efferentia
 ot de Graaf, to the apices of the cones of the epididymis.!
   524. The Epididytnis,  lying on the  side  of the testicle
 and  consisting of one vessel about thirty feet in length, is
 less, and divided into about twenty glomerules or cones at
 the part called its head,}, and is continued into the vas defe^
 rcns, at its lower part,  which  gradually becomes thicker^
 and  is  denominated its tail,
   525. Each vas deferens,  ascending towards  the  neck of
 the  urinary bladder and converging  towards  the  other
 under the prostate gland,  is then directed backwards  and
 dilated  into  the vesiculae seminales,  in such  a manner,
 that the common  mouth both  of the  vesicles and vasa
 deferentia,  opens  into the urethra, behind  the caput  gal-
 linaginis.^J
   526. The vesicular seminales,  which  adhere to the pos-
 terior  nnd  inferior surface of the bladder,  surrounded by
 an  abundance  of fat, resemble two little intestines, va-
 riously reflected, and branching into numerous blind ap-
 pendices.
  They consist of two coats, nearly similar to those of the
 gall   bladder;  the one  strong,  and  of  the desription
usually  termed  nervous;  the  other  interior, delicate,
abounding in cells, and divided into compartments  by pro-
  • Haller De viis seminis in the Philos. Trans, No, 494, fig. 1. g. g.
  f De Graaf De  Viror. orgatiis generationi inservientibus.  Tab. iv. fig
1.2.
  t Vide Alex. Monro fil. Observations anatomical and physiological. Edinb.
1758, 8vo. tab. i. E. E. E. F. G. H.
  § B. S. Albinus. Annotat. Acad. L. ii. tab. iii. fig, 1.
  fl B. S. Albinus. 1. o, L. iv. tab. iii. fig. 1. 2. 3. 
 -80        OF  THE  GENITAL FUNCTION IN MAN-

 minent ridges, like  those found in the  cervix of the  gall
 bladder.*
   527. In  these passages is slowly and sparingly secreted
 and contained from  the time of puberty, the semen, a very
reniarkable  and important  fluid,  of a  milky  yellowish
 colour,f  of a  peculiar odour,  of the  same  viscidity as
mucus,  and of great  specific  gravity,  of greater indeed
than any other fluid of the body4
   528. Semen  has  also this peculiarity, first observed  by-
Lewis Ham of Dantzic, in the  year  1677,$ of being ani-
mated by an infinite number of small worms visible by the
microscope, of the kind denominated infusoria, and of  dif-
ferent figures in different kinds of animals.  In man,^j these
spermatic animalcules are oval and have very fine tails: they
are said to be found in prolific semen  only, so that they are
in some degree an adventitious criterion of its prolific  ma-
turity ;  I  say  adventitious, because  I hope  there  is  no
necessity, after  so  many  weighty  arguments,  and  obser-
vations,**  at present to remark, that they have no fecunda-
  * See besides the figures by Graaf, Haller,  Albinus and Monro, espe-
cially the beautiful one by Fl. Caldani in his Opusc. Anat. p, 17.
  ] The opinion of Herodotus respecting the  black semen of Ethiopians,
refuted jn ancient times by Aristotle, has, to my surprise, been taken up
in modern times by Le Cat, de Pauw, Wagler, &c.
  ± F. B. Ossiander asserts,  " that fresh semen emitted under certain
circumstances, is occasionally phosphorescent."  De  causa insertionis pla-
centa in uteri orificium.  Gotting. 1792, 4to. p. 16.
  § Vide  Fr. Schrader,  De microscopior. usu in nat. sc. et anatome.  Got-
ting. 1681, 8vo. p. 34.
  ^ W. Fr. v. Gleichen,  Ube'r die Saamen und  Infusiomthierchen, Nurimb.
1778, 4to. tab. i.fig. 1.
  ** Consult especially Laz. Spallanzani, both in  his  Opuscoli di fisica
anintale e vegetabile. Milan. 1776, 8vo. vol. ii. and  in  his Dissertazioni,
Sec. ibid. 1780, 8vc. vol. ii. 
OF THE GENITAL  FUNCTION IN MAN.        281
iing principle,  nor  much less are  the germs  of future
offspring (G).
   529.  The genital fluid gradually collected in the vesicles
is retained for  subsequent excretion,  and  by its  stay ex-
periences  changes nearly similar to those  of the bile in
the gall bladder;—becoming  more inspissated  and con-
centrated by tho removal of its watery  portion.*
   530.  As the whole  of the testis  and spermatic  chord
abounds  in lymphatic vessels  which  carry  back to  the
blood  a fluid with a seminal  impregnation  and thus faci-
litate the  secretion  of semen in the  manner before  de-
scribed (477) ;  so the vesiculae seminales are likewise  fur-
nished with a similar  set of vessels, which,  by absorbing
the inert watery part,  render the  remaining semen more
powerful.
   531.  But I very much doubt whether  the semen is ever
absorbed  during health;  still  more  that  it ever passes
into the  neighbouring veins ;  and most  of all,  that by
this absorption, if it  does  occur,  unseasonable venereal
appetites  are prevented;  since,  if  we compare  the phe-
nomena of animals procreating at particular periods, with
the constitution of  those  which are  castrated,  we must
conclude,  that  this  absorption is rather the  cause of  un-
governable and almost rabid lust.
  * A parodoxical opinion  was formerly entertained by some,  that the
semen is not discharged from the vesiculs seminales but from the vasa
deferentia, and that the fluid of the vesicles is not truly spermatic and
derived from the  testis, but of quite  another kind, secreted in peculiar
glands belonging to the  vesicles.   This  has  gained  some advocates
among the moderns.  J. Hunter, On certain parts of the Animal Economy,
p. 27.  J. A. Chaptal,  in the Journal  de Physique. Febr. 1787, p. 101.
It has been refuted by Sbemmerring, in the third volume of the Bibliothe-
ca Medica, which I edited, vol. iii. p. 87. (H.)
                            O  o 
JS2        OF THE GENITAL FUNCTION IN  MAN.

  532.  I conceive  that this end is accomplished in a very
different mode, by a circumstance which occurs,  as far as
I have been able to discover, in no a nimal but man,—by
nocturnal pollutions, which I regard among  the  natural*
excretions,  intended  to liberate   the   system from  the
otherwise  urgent  superfluous  semen,  more  or  less  fre-
quently, according to  the variety of  temperament  and
constitution.!
   533. The semen is never  discharged pure but mixed
with  the prostate fluid,  which is  very much of the ap-
pearance of the white of egg, and has acquired its name
from  the organ by  which it is produced, an organ of some
size,  of a  singular and very compact texture, lying be-
tween the vesiculae seminales and bulb of the  urethra,  and
commonly denominated  prostate  gland.   The  passages
for the course of  this fluid are  not well  known, unless
perhaps they communicate  with the  sinus of the seminal
caruncle,  the middle of the  orifice of which opens  into
the urethra^ between  the two mouths(525) of the seminal
vesicles.
  534.  The male urethra is the common emissary of three
different fluids,  the urine,  semen,  and prostate fluid.  It
is  lined with  mucus which  proceeds  from numerous
sinuses dispersed along the  canal.§  We find it surrounded
  * Chr. R. Jaenisch, De pollutione nocturna.  Gotting. 1795, 4to.
  ! I willingly grant that  barbarous nations, of a phlegmatic tempera-
ment and copulating promiscuously, do not require tnis excretion; but I
must contend, that it is a perfectly natural relief, in a young man, single,
sanguineous, full  of juices, with a strong imagination,  and living high,
although enjoying the completest health.
  t Morgagni's Adversar. Anat. iv. fig. 1. 2.
  * J. Ladmiral, Effigies penis humani.  L. B. 1741,  4to. 
            OF THE  GENITAL FUNCTION IN  MAN.         2&S

by  a  spongy  texture, upon which lie  two other spongy
bodies* of much greater thickness,  constituting the greater
part of the penis.   The penis  is terminated anteriorly by
the glans,  a continuation of  the spongy  texture,  usually
covered by a  delicate  and very moveable skin which is
destitute of fat, and, at  the corona of the gland,  forms  the
preputium  which moves over the  gland as the eyelids do
over  the eyeball.   The internal duplicature of the prepu-
tium,  changing its  appearance, is reflected over the gland,
like the albuginea of the eye, and is beset at  the corona
with  many Littrian! glands, similar to the Meibomian of
the eyelids, and secreting a peculiar smegma.!
  535.  The virile  organ  thus  constructed,   enjoys  the
power of  erection ;  i.  e.  of becoming  swollen and  stiff,
and changing its situation, from  the impetuous  conges-
  * Ruysch.  Observat. anat.  chirurg. Centur. page 99, fig.  75—82. and
Ep. problemat. xv. fig. 2. 4. 6. 7.
  T. H. Thaut. De virga virilis statu sano et morboso.  Wirceb. 1808, 4to.
fig.l.
  ! Morgagni. Adversar. anat. 1 tab. iv. fig. 4. 1. k.
  $ This smegma in young men,  especially  when  heated,  is well
known to accumulate readily and  form an  acrimonious caseous coagu-
lum.  The inhabitants of  warm climates are particularly subject to this
inconvenience, and the chief use of circumcision appears to  be the pre-
vention of this  accumulation.  We  know that  for this  reason Christians
in the scorching climate  of Senegambia occasionally cut  off tlie prepu-
tium, and that uncircumcised Europeans residing in the East, frequently
suffer great  inconvenience.  Guido de Cauliaco, the celebrated restorer
of surgery in his day, who flourished in the middle of the fourteenth
century, said that circumcision was  useful to many besides Jews  ancl
Saracens, " Because there is no accumulation of sordes at the root  of the
gland, nor irritation of it."  Cldrurg. Tr. vi. doctr. ii. p. m 111 
284
OF THE GENITAL FUNCTION IN  MAK.
tion and  effusion*  of blood into  its corpora  cavernosa
either  by  corporeal  or  mental  stimulus,  and  of  detu-
mifying  and  collapsing after the return of the bloodf (I).
  536.  When in a flaccid  state, it is remarkably  bent at
its  origin  from  the  neck  of the  bladder,!  and  thus per-
fectly adapted for the  discharge of urine, but quite unfit
for the  emission  of semen,§ because  the  origin of the
urethra  then forms  an acute angle with  the openings of
the seminal vesicles.
  537. When the penis swells  from  desire,  the prostate
fluid  generally flows first, and  indeed is often discharged
pure, rarely  together with  the urine :  its principal use is
to  be emitted with  the semen, either by its albuminous
lubricity correcting  the viscidity  of the former and pro-
moting   its emission,  or  contributing something peculiar
to generation.
   538.  The emission of semen is  excited  by its abundance
in  the vesicles and by sexdal instinct: it is effected by the
violent tentigo which prevents the  course of the urine, and,
as it were, throws the way open for the semen;  by a kind
of spasmodic contraction  of the vesiculae seminales, a con-
vulsion  of the  levatores  ani** and of the  acceleratores
  * Vide Theod. G. Aug. Rooze, Physiologische Untersuchungem.  Brunsw.
1796, 8vo. page if.
  ! A phenomenon worthy of remark, from the light which it throws  on
this function in general, is the erection so frequently observed in those
who are being executed, and especially in those who are being strangled.
Consult after Garmann's farrago  {de Miraculis Mortuorum, i. xi. 7- sq)
Morgagni, De sed. et cans. morb. xix. 19, et sq.
  t See Camper. Demonstration, anat. pathologic. L. ii. tab. iii. fig. 1.
   § Gysb. Beudt, De fabrica et usu viscerum uropoieticorum.  L. B. 1774,
4to. reprinted in Haller's Collect, disput. anat. T. iii. tab. iii.
   •* Carpus in Mundinum, page 190, b. et 310. 
           OF THE GENITAL FUNCTION IN MAN.         285

urinae, and by a short and less  violent  succussion of the
whole system, almost of an epileptic  nature,  and followed
by a great depression of the strength* (K).
                        NOTES.

   (A)  Instances  of more than two testes are extremely
rare.   Three, four, and even five, are said to have existed,
and Dionis  in his Anatomy informs us,  that he  himself
once saw three in a person of rank,  who  assured him that
the  greater  part of  his  family were  equally well  pro-
vided.!   Haller  quotes several  authors for  similar in-
stances.   Unless such  cases are related by an  experienced
medical man from his own observation, they deserve no
credit,  and  even then  must be  regarded with suspicion,
if anatomical examination does not  prove the additional
bodies  to be analogous to testes no less  in structure  than
in form and  situation.   The  late eccentric Dr. Mounsey,
who ordered that his body should either  be dissected by
one of his friends or thrown into the Thames, was found
to have in his scrotum a small  steatom, which during .life
must have given the appearance of three  testicles.
   Writers who related these wonderful  cases completely
disagree in their account of the powers of the  individuals,
  * For which reason Zeno, the father of the  Stoic philosophy, called
the loss of semen the loss of part of the animating principle. (M.)
  f L'Anatomic des corps humaint.  Demonstration quatrie^me. Sect. 1. 
286
OF THE GENITAL FUNCTION IN MAN.
 some asserting them to  be prodigious, others greatly below
 those of ordinary men.
   One testis is  commonly larger than the other, and the
 right  spermatic  chord being for the most part shorter
 than the left, the right testis is generally the higher.
   (B) The original situation of the testes  accounts for the
 circumstance of their blood vessels arising from the  loins,
 as Mr. Hunter remarked, for parts generally derive their
 vessels from  the  nearest  scource.  The  same  applies  to
 their nerves.   Hence too  the right spermatic  artery fre-
 quently springs from the right renal  as being nearer than
 the  aorta, and  the  left spermatic vein  frequently  pours
 its  blood into the left renal as being  nearer than the in-
 ferior vena cava.
  The  original situation  of  the testes accounts also lor
 the circumstance of  the vas  deferens arising  from  the
 lower  part  of the  epididymis and bending  upwards;  in
 the foetus this  is not  the case, but it is the necessary con-
 sequence of the subsequent change in the situation of the
 testis.*
  C.  The descent of the  testes  into  the scrotum  must,
 I  apprehend,  arise  from  the  growth  of  their nerves
 and  vessels,  and  the direction afforded by the contrac-
tion  of  the  gubernaculum;  the  growth  of the former,
 and* therefore the whole process, is accounted  for  in the
minds of some by  the contraction of the   latter.!   Mr.
 Hunter's  original  account  of  the'  gubernaculum  may
not be unacceptable.  " At this  time of life, the  testis
 is connected in a  very  particular manner with the parietes
of the  abdomen, at that place where  in adult bodies, the
  • Hunter, A description of the situation of tfte testis in the fcttus, with its
descent into the scrotum. Obs. 13.
  f Bichat's Anatomic descriptive. T. ii. p. 234. 
            OF THE GENITAL FUNCTION IN MAN.        287

spermatic vessels pass out, and  likewise with the scrotum.
This connection is  by means  of a  substance which runs
down from the lower end  of  the testis to  the scrotum,
and which at present I  shall  call the ligament or guber-
naculum  testis, because  it  connects the testis with the
scrotum,  and seems to direct its course through the rings
of  the  abdominal muscles.  It  is of a  pyramidal form;
its  large bulbous head is  upwards,  and fixed to the lower
end of the  testis   and epididymis,  and  its  lower and
slender extremity is lost in the cellular membrane of the
scrotum.   The upper  part  of this ligament is  within the
abdomen,  before the psoas, reaching  from  the testis  to
the groin,  or  to where the  testicle is  to pass  out of the
abdomen; whence the ligament runs down  into the scro-
tum, precisely  in  the same  manner   as  the  spermatic
vessels pass down in adult bodies, and is there lost.  That
part of the ligamentum testis,  which is  within  the abdo-
men, is  covered by the peritonaeum all round, except at  its
posterior part, which is contiguous to the psoas, and con-
nected with it by the reflected peritonaeum and  by  the cel-
lular membrane. It is hard to say what is the structure or
composition of this ligament: it is certainly vascular and
fibrous, and the fibres run in the direction of the ligament
itself, which is covered by the  fibres of the cremaster  or
musculus testis, placed immediately behind the peritoneum.
This circumstance is not easily  ascertained in the  human
subject; but is very evident in  others, more especially in
those whose testicles remain in  the cavity of the abdomen
after the animal is full grown."*
   (D) We know that the  skin of every part relaxes  by
heat and  contracts by cold, although it  is not  muscular :

  • .1 Description of the situation of the testis  in  the fxtus, with its descent
into the scrotum. Obs. 6, 
288        OF THE GENITAL FUNCTION IN MAA*.

in the cold fit of an  ague,  it is constricted throughout so
forcibly  as  to have acquired,  during this state, the appel-
lation of Cutis  Anserina.  The  scrotum being  much
more lax than any other portion of the skin, experiences
these  effects to  the  greatest  extent.   What  is  termed
dartos is merely thick cellular membrane.
   (E) Another coat exterior to the rest, is described by
M.  Roux, and  termed Envelope fibreuse.  It is an elon-
gated  sac, large below to contain  the  testis and epidi-
dymis, and narrow above, affording a  sheath to the chord.
It vanishes among  the cellular membrane of the  ring.*
M.  Roux  considers  this  coat  as  having been known to
Haller, from the following passage in Haller's account of
the  testicle.   "  Ita  fit ut  interiores  cavae  duse sunt;
superior vasculis  spermatids  circumjecta; inferior  testi
propria."  But Haller continues thus, " Ita saepe se habet,
ut etium aquas vis aut  in partem testi propriam solam in-
tacta parte  vasculosi  funiculi,  aut  in  istam solam, in-
tacta testis  vagina,  effundatur,  neque flatus  impulsus de
ea vaginali  ad istam  commeet.!"   He appears therefore
to describe merely the tunica vaginalis of  the chord and
testis.
  (F) The  cremaster deserves  a  little  attention.  This
muscle arises from the  superior  anterior spinous  process
of the ileum, from  the transversalis abdominis,  the in-
ternal  surface of the Fallopian ligament and neighbour-
ing  parts, and, passing through the  ring, spreads upon
the  chord,  vanishing upon  the beginning of the  testi-*
ele.   Its  office  is  evidently  to support the  testicle and
draw  it  upwards  against  the  groin, during procrea-
• Bichat's Anat. Descrip. T.ij. p. 176.
t Elementa Physiologia. T. vij. p. 420. 
            OF THE GENITAL FUNCTION IN MAN.        289

 tion.   In those animals,  whose testes, instead of  hanging
 in the scrotum,  lie in  the perinamm, the groin, or the
 abdomen, this muscle is, as might be expected, much less
 considerable.
   It may here be mentioned,  that the human testes do not
 always descend into the  scrotum, but occasionally remain,
 one or both, in  the groin or abdomen.   Individuals so
 circumstanced were called testicondi  by the ancients.  A
 ridgil  is a  bull  in which one only has descended.   In
 these  instances the generative powers  are not impaired;
 a testicle which  has  not descended  is prevented by the
 pressure  of the  neighbouring parts  from fully  evolving
 itself, but such persons,  it is certain, "militant  non sint
 gloria."  The generative powers  indeed  are not impaired
 by the removal  of  one  testis:  the  Hottentots  are  said
 always to cut away one  from their sons, on  arriving  at
 eight  years  of age, to render them  lighter for  running.
 And we read in Varro, that if a bull is  admitted to a cow
 immediately after both testes  are removed, impregnation
 takes  place, " Exemptis testiculis,  si  statim  admiseris,
 concipere (vaccas)"*.  This at least is certain, that  some
 men have perfectly  performed the act of copulation after
 castration!.   In a case mentioned by Mr. Astley Cooper,
 in his surgical lectures, the complete power remained some
 time after the removal of both  organs, but gradually di-
 minished.
   (G)  According to  Haller,  Lewis  Hamme,  a young
 German,  discovered the seminal animalcules, and  shewed
them to Leuwenhoeck;  and  the sagacious  Dutchman,
  * De Re Rustica. ii- 5.
  t See Cabrol, Philostrate, Scaliger De subtilitate, and Martin Schurig's
Sperxnatol. Quoted in Ver\ 's Histoire naturelle de VHomme.
                          PP 
290        OF THE GENITAL FUNCTION IN MAN.

catching eagerly at the discovery, published an  account of
them, illustrated by plates.  Hartzoeker, ambitious of the
honour of the discovery,  wrote  upon the subject the fol-
lowing  year, and  asserted that  he had  seen the animal-
cules  three years before they  were observed by Hamme.
The subject, being the very summit of filthiness, excited the
earnest attention of all Europe.  Physiologists, Naturalists,
Popish  Priests,  Painters, Opticians, and  Booksellers, all
eagerly  joined in the pursuit  of  the seminal animalcules,
and the  lascivious Charles the Second, of England, com-
manded them to be presented to him swimming and frisking
in their native fluid.  Some of the curious could not find
them.   Others not only  found  them, but  ascertained their
length to be the T77r3T7Tr part  of  an inch, their bulk such
as to  admit the existence of  216,Q00 in a sphere  whose
diameter was the breadth of a  hair, and their rate of tra-
velling to be nine inches in an hour.   They saw them too
in the semen of all  animals, and/what is remarkable, of
nearly the  same size and  shape  in the  semen  of the
largest  and of  the  smallest,  in  the semen  of the sprat
and  of  the  whale ; they  could  distinguish   the  male
from  the female ;  in the semen of a ram, they  beheld
them  moving forwards  in a  troop,  with great gravity,
like a flock  of  sheep ;  and  in  the human  semen,  Da-
lenpatius  actually saw  one indignantly  burst  its wormy
skin,  and  issue forth  a  perfectly formed human  being.
The  little  creatures would  swim in shoals  towards a
given point,  turn  back, separate,  meet again, move on
singly, jump out,  and dive in  again, spin round, and per-
form  various other  feats, proving  themselves,  if not the
most  delicate,  at least  the  most droll,  beings that  ever
engaged the attention of philosophers.  Their strength of
constitution being an  important  object  of  enquiry,  thev 
           OF THE GENITAL FUNCTION IN MAN.       291

 gave proofs of their vigour, not only by surviving  their
 rough passage through  the  urethra three, four,  and seven
 days,  but by impregnating a female at the end of this time,
 and, on being removed from her, by impregnating even a
 second.   Sure never was so much folly and bestiality before
 committed under the name of philosophy.
   A. Kauw Boerhaave, Maupertuis,  Lieutand, Ledermul-
 ler, Monro Secundus, Nicolas,  Haller, and indeed nearly
 all the philosophers of Europe, were  satisfied of the exist-
 ence of the animalcules.  Buffon and his followers, preju-
 diced  in  favour of an hypothesis, although they did not
 deny that the semen contained innumerable rapidly moving
 particles,  contended that  these were  not animalcules, but
 organic particles;  and Linnaeus imagined them to be inert
 molecules, thrown into agitation by the warmth of the
 fluid.   Their  reality,  however,  might be  regarded  as
 established.  But  finally  to determine  the  question, and
 accurately to ascertain every circumstance relating to them,
 the  celebrated Spallanzani began a long course  of obser-
 vations and experiments  about the middle  of  the last
 century,  unbiassed in  favour  of any  opinion, and endea-
 vouring to forget  entirely all  that had been written upon
 the subject.  The  human semen  he procured from bodies
 immediately after  death, and that of  animals  either after
 death or during life.
   He found in the former innumerable  animalcules, with
 an oval body,  and a tail,  or appendix, tapering to a point.
 This appendix, by moving from side to side,  propelled
 them forwards.  They  were in  constant motion  in every
 direction.   In  about  twenty-three minutes  their move-
ments  became more languid,  and in  two or three hours
 they generally  died,  sinking to  the bottom of  the fluid,
 with their appendices extended.  The duration of their 
292        OF THE GENITAL FUNCTION IN MAN.
life,  however,  depended much upon the temperature of
the weather; at 2  below 0 (Reaumur) they died in £ of
an hour ; while at 7° they lived two hours, and at 12 J, three
hours and three quarters.  If the  cold was not too intense,
they recovered  upon the  temperature being raised ; when
only 3 or 4 below 0, they recovered after a lethargy of four-
teen hours and upwards: and, according to the less intensity
of the cold, they might be made to pass from the torpid to
the active state more frequently.   They were destroyed by
river, ice, snow, and rain-water ; by sulphur, tobacco, cam-
phor, and electricity.   Even the air was injurious to them ;
in close vessels,  their life was prolonged to some days, and
their movements were not constant  and  hurried.  They
were of various sizes, and perfectly distinct from all species
of animalcules  found  in vegetable infusions, &c.  The se-
minal animalcules of different kinds of animals had generally
each some peculiarity.   In  short, Spallanzani completely
confirmed  the  chief  observations of  Leuwenhoeck, and
satisfactorily explained the sources of the inaccuracies of
other enquirers.*
   Although these  beings are most numerous in the semen,
he detected  them occasionally in  other fluids ;—in  the
mesenteric blood of female  frogs  and salamanders, and in
the blood of a tadpole and a .calf.
   It were to be wished that another Spallanzani would pro-
secute these enquiries.
   According to Vauquelin's analysis of the semen, 100 parts
contain,
  * Opuscules de Phisique animate et vegetable, par M. L'Abbe" Spallan-
zani, traduits de Vhalien, par Jean Senebier. T. ii. Observations et Ex-
periences sur la Prtits Vers Spermatiques de I'Homme et des Animaux. 
          OF THE GENITAL FUNCTION  IN  MAN.      293

         Of water    -    -    -     -9.0
             Mucilage      -    -     -     6
             Phosphate of lime              3
             Soda    -                    1
   In some days it putrifies, and becomes covered with the
byssus septica.*
   (H)  Mr. Hunter's arguments  are  very forcible.    1.
" The semen, first discharged from the living body, is  of
a blueish white colour,  in consistence like  cream, and
similar  to  what  is  found  in  the vasa deferentia  after
death;  while that  which  follows is  somewhat like the
common mucus of the nose, but less viscid.  The semen
becomes more fluid upon exposure  to the air, particularly
that first thrown out; which is the very reverse of what
happens to secretions in general.  The smell of the semen
is mawkish and unpleasant, exactly  resembling that of the
farina ©f a Spanish  chesnut; and  to the taste, though  at
first insipid, it has so much pungency, as, after some little
time, to  stimulate  and  excite a  degree of heat  in the
mouth.   But the  fluid  contained in these  vesiculae, in a
dead body, is of a  brownish colour, and  often varies  in
consistence  in different parts of the bag,  as if not well
mixed.   Its smell does not resemble that  of the semen,
neither  does it become more fluid by  being exposed  to
the air."   On opening two  men immediately after death,
the contents of the vesiculae were of a lighter colour than
he  usually found  them  in  persons who had been some
time dead, and, in one of  the instances, so  fluid as to run
out upon cutting  the vesiculae, but they were similar  to
the semen neither in colour nor smell.   An examination  of
the vesiculae  of the horse, boar, rat, beaver, and guinea-
pig, afforded the same  results.   In the last animal, the
* Annates de Chemie. T. x. 
 294      OF THE GENITAL  FUNCTION IN MAN.

 contents near the fundus of the vesiculae were viscid, and
 gradually firmer, till, near the opening into the urethra,
 they were as solid as common cheese, and no such sub-
 stance could be detected in the vagina of the female after
 her union with the male.  2. During lasciviousness, the tes-
 ticles swell, and they become painful, if the semen is not dis-
 charged ; in coition, it may be added,  they  are drawn for-
 cibly  by the cremaster against the pubis, as if to assist the
 discharge of their contents at the period of emission.    3.
 In the  old  and debilitated,  the vesiculae are as full as  in
 the young and vigorous.  4. Nay, in four  men,  who had
 each lost a testicle, the vesicula on one side was equally
 full as  on  the other,  although  they had survived the
 operation a considerble length of time.   The same was
 discovered in two cases, where, by mal-formation, one testi-
 cle had  no communication with the corresponding vesicle.
 In the gelding  and the stallion their contents are  similar,
 and nearly equal in quantity.   The  vas deferens has no
 communication in some animals with  the vesiculae, and  in
 others, as the horse,  where  a  communication  does exist,
the common duct is not of sufficient length to permit the
regurgitation of the  semen into the  vesiculae.    5. Some
 animals, especially among the carnivora, have no  vesiculae
 seminales, yet  in  their  copulation they differ not  from
those  which have.  M. Richerand,  indeed, asserts, that
animals destitute of these organs  are longer in coition
than others, from having no reservoir for an accumulation
of semen.*   But he is mistaken.   For, on  inspecting Cu-
vier's account of animals without  and with vesiculae, no
connection whatever   appears  between their presence or
absence and'the length of copulation.
  In opposition to these arguments I have only to remark,
* Element de Physiologic Chapitre x. 
          OF THE GENITAL  FUNCTION IN MAN.      295

that a fluid, gently  propelled along the vas deferens, does
not pass  into the urethra, but  regurgitates into the vesi-
culae,* and that  in  a case of seminal weakness, which I
lately saw, the act of straining at the water-closet  instantly
discharged from  the  urethra, without the least sensation,
a large quantity of a fluid, which the  patient, who was of
course unprejudiced in favour of any opinion, assured me
was exactly similar  in colour, consistence, and odour, to
that of a nocturnal  emission.   The compression could
not have sqeezed this fluid from the testes.   If  a  partizan
of Mr. Hunter should say that  the extremities  of the vasa
deferentia afforded it, I reply, that Mr. Hunter found them
full of the same kind of fluid as the vesiculae.
   (I) Accumulation of blood, it  is supposed, may be pro-
duced in three ways.   1. By an impediment to its return:
but there  is  no reason whatever,  to ascribe the  ordinary
erection  to compression.   2.  By an increased  flow of
blood to a part, so that  the  vessels receive it faster than
they convey it away.   Here  the vessels  of the  part, in
which the accumulation exists, are said by some to act
more violently than usual;  by  others, the neighbouring
larger vessels which  supply these:  their  frequency of
action, however,  is   not  increased,  but  always   remains
correspondent with  that of the  heart.  Were  the vessels
of the part itself to  act more violently than usual, that is
to say, to contract  to a smaller and rehix to a greaterdi-
mension than usual, more blood  would indeed subsist in
them  during their relaxation, but less than usual would
subsist  in them  during their contraction, and there could
be no accumulation,  no inflammation.   If  the  neighbour-
ing large vessels  act  more violently than  usual, they may
be conceived to produce an accumulation of blood and  a
* Winslow, Ruysh, Duverney, and others, quoted by Haller. 
296      OF THE GENITAL FUNCTION IN MAN.

distension of the smaller vessels.   3.  If the vessels of any
part become dilated, and do not  contract in proportion,
this circumstance will  be sufficient to produce an accu-
mulation, without any necessity for supposing an increased
action of  the neighbouring larger  vessels.   This explains
inflammation:  and in Bichat's  Anatomie Descriptive, this
explanation is given  of  erection.    The corpora cavernosa,
which always  contain  florid blood, spontaneously  dilate,
and  accumulation  ensues.    For this purpose it  is not
necessary that they  should be muscular, but Mr. Hunter
asserts their muscularity: in a horse,  he found them mus-
cular to the eye, and they contracted upon being stimu-
lated.
  As to  the final cause  of erection,  the organ,  by ac-
quiring increased bulk,  firmness, and  sensibility, becomes
adapted for both affording and experiencing to the  utmost
extent the effects of friction, both as exciting pleasure and
as stimulating  the secreting vessels ;  the urethra,  by be-
coming longer and narrower, renders the emission more
forcible.
  (K) The discharge of semen resembles the discharge of
fluids from all glands.   It is excited by the abundance of
the fluid, by mental stimulus, or by mechanical irritation of
the extremity of the excretory duct, for in such a point of
view must be regarded the friction of the glans penis in
copulation.  The fluid is  accumulated in  the  bulb  of the
urethra, for it must be  accumulated somewhere  to be
emitted so copiously, and no other use can be  assigned to
the bulb;  and if the vesiculae do  not  receive it, no other
part but the bulb can ; and besides,  it is upon the bulb
that the muscular contraction of the  venereal paroxysm
first acts.   " The semen,  acting as a stimulus to the cavity
of the bulb of the urethra, the muscles of that part  of the
canal are thrown into action, the fibres nearest the bladder 
OF THE GENITAL FUNCTION IN MAN.
297
 probably act first, and those more forward in quick succes-
 sion, and the semen is projected with some force. The blood
 in the bulb of the urethra  is by  the same  action squeezed
 forward, but, requiring a greater impulse to propel it, is ra-
 ther later than the semen, on which it presses from behind ;
 the  corpus  spongiosum, being full of blood,  acts almost  as
 quick as undulation, in which  it is assisted  by  the corres-
 ponding constriction of the urethra, and the semen is hurried
 along with  a considerable velocity."*
   (L) If Gall is right, in placing the seat of sexual desire
 in the head, this kind of erection may be explained by
 supposing the irritation, arising in the cerebellum from the
 great accumulation of its blood, to produce a correspondent
 irritation in the organs of generation :  thus the epileptic
 paroxysm  is not unfrequently  accompanied by an  emis-
 sion.   Nocturnal emissions occur most frequently after a
 person has been long in bed and supine—the cerebellum the
 lowest part.
   (M)  Zeno's  practice was conformable to his principles.
 He embraced his wife but once in  his life, and then out of
 mere politeness.
   Epicurus, Democritus,  &c.  were  nearly of the same
 opinion  with Zeno ; and the Athletse, that their strength
 might be unimpaired,  never married.   The  rabbies, in
 their anxiety to preserve their  nation, are said to have or-
 dered, with the view of preventing the loss of vigour,  that a
peasant should indulge  but  once a  week, a  merchant but
once a month, a sailor but twice a year,  and a studious man
but once in two years.
  * Hunter, Observations on the glands situated between the rectum and blad-
der, called vesicula seminales. Obs. 45.
                          Qq 
298     OF THE GENITAL FUNCTION OF  WOMEN.
                   SECT. XXXVII.

  OF THE  GENITAL  FUNCTION  OF WOMEN  IN GENERAL.

   539. As the male organs are fitted for affording, so the
female organs are fitted for receiving, and are correspond-
ently opposite  to  the former.   In some parts, the organs
of each sex are very analogous to each other  in  structure.
Thus the clitoris, lying under the pubis in the superior com-
missure of the labia,  agrees in many  respects with  the
penis of the male, although distinct from the urethra, and
imperforate  and  extremely small in well-formed  women.
It is recorded to  have been, in  some adult females, of as
comparatively large size as we stated it usually to be in the
foetus (492), and  these instances  probably  gave  rise  to
most of the idle  stories of hermaphrodites.*   Like  the
penis,  it has  its  corpora cavernosa,  is capable of erection,
covered with a prepuce, and secretes a smegma! not unlike
the Littrian (525).
  * Vide Haller in the Comment. Soc. Scient.   Gotting. vol. i. p. 12,
sq.   Plates are given by Gautier in bis Observ. sur l'Hist. Nat. 1752,
4to.
  f In warm climates it too is liable to accumulation and acrimony,
and has hence given occasion to the custom of female circumcision in
many hot  parts of Africa and Asia.  Carsl. Niebuhr has given a re-
presentation of the genitals of a circumcised Arabian female, eighteen
years of age, whom  he himself was singularly fortunate in examining
during life, when on his oriental tour.   Beschreib. von Arabien. p. 77'.
and Osiander's Deuhwrdigkeitenf'ur die Heiliunde, &c.  vol. ii. tab. vi.
fig. 1. 
         OF  THE GENITAL  FUNCTION OF  WOMEN.      299

   540.  From the  clitoris the  nymphce descend, also oc-
casionally of great size,* the source of other idle tales,!
and, like the  clitoris,  possessing  a  high  degree of sensi-
bility.   They appear in some measure to direct the  stream
of  urine,  because  the  opening of the urethra,  which  is
very short in females, and frequently ciliated, as it were,
with  small  papillary  folds,!  nes  under  their commence-
ment.
  541. Under the  termination of the urethra lies the open-
ing of the vagina,  surrounded with  various kinds of cryp-
tae ; v. c.  the lacunae urethericte  of De  Graaf,§ and the
orifices of  the  prostates, as  they  are improperly termed,
of Casp. Bartholin,!] which secrete an unctuous mucus.^]
  * Their number has likewise been found various.   Vide Neubauer
De triplici nympharum ordine.  Jenac, 1774, 4to.
  f I allude to the singular ventral  skin of the  Hottentot women.
Wilh. Ten. Rhyne, from personal inspection long ago, considered it as
enormous pendulous nymphae.  Depromontorio b. spei. p. 33.  I have
treated this point at large in my work, De Gen. Hum. Var. Nat. 242.
ed. 3.  Steller relates something similar in regard to the Kamtschat-
kan women.  Beschr. v. c. Lande Kamtschatka. P. 300.  (A)
  ! I find the opening of the urethra surrounded  with very beautiful
cutaneous cilia of this kind, in a remarkable specimen of the genitals in
a woman upwards of eighty years of age.   The hymen is entire, and all
the other parts most perfectly, and, as it were, elaborately formed.
They are preserved in my museum,  and my friend and colleague, Osi-
ander, has represented them in a plate.  Libio Citato.  Tab. v.
  § See Jo. James Huber's plates of the uterus, among those of Haller.
fasc. 1. tab. 2. fig. 1. g.
  || Ibid. fig. 1. b. b—fig. 5. d.
  If Such also are the two foramina,  very frequently observed in living
women, by J. Dryander, at the extremity of the vagina.  Nic. Massa's
Epistol. Medicin. t. 1. p. 123. b. 
500    OF  THE GENITAL FUNCTION  OF WOMEN.

  542.  Across the opening of  the  vagina, the Hymen* is
extended,—a membrane generally circular, found,  as far
as I know,  in the  human subject alone, and of  no physi-
cal use hitherto discovered.
  The remains of  the lacerated hymen become the  carun-
cula' myrtiformes, which are of no regular number, and
are infallible signs of the loss of virginity. (BJ
  543.  The vagina,  ascending between  the  urinary blad-
der and rectum, consists of a  very vascular cellular  paren-
chyma;  is surrounded interiorly by  the  constrictor cunni,]
and lined internally with a very soft coat, which is marked
by two  columns of ruga?,] an  interior  and posterior,^ pour-
ing forth a mucus into its cavity.
  544.  Upon the  superior  part  of the vagina  rests the
uterus, suspended  on either  side by  its broad ligaments.
Its cylindrical cervix ||  is  embraced  by the  vagina, and
perforated by a narrow canal,  which, like  the vagina, is
marked  by  rugae, denominated the arbor vitse,  and is
generally lined with a viscid mucus at each  extremity, but
particularly at the superior.
  545.  The  substance  of the  uterus is peculiar,  a very
dense  and  compact  parenchyma^,  abounding  in  blood-
  * John Wm.  Tolberg, De  Varietate  Hymenum.  Hal.  1791, 4to.
Osiander, I.e. tab. 1.—vij.
  f Eustachius. Tab. xiv. fig. 1. x. x.
  Santorini. Tab. Posth. xvij. 1.1.
  \ Huber, De Vagina Uteri Structura Rvgosa, necnon de Hyeme, Gotting.
1742, 4to.
  § Vide Haller's Icones Anat. fasc. ij. tab. vj. fig. 1. 2.
  y Roederer Icones Uttri Humani.  tab.  vij. fig. 2. 3. 4.
  ^fj. Gotter. Weisse  (Fracs. Rud. Boehmer) De Structura Uteri non
musculosa, sed celluloso Vasculosa. Vitemb. 1784, 4to.
  J. G. Walter Was ist Geburtshulfe. Berlin. 1808, 8vo. p. 54. 
         OF THE GENITAL FUNCTION OF WOMEN.      301

vessels, which run in a curious serpentine direction* and
are destitute of valves.   It  has also a supply of lympha-
tics ;f and a great number of nerves,! whence its remarkable
sympathy with other parts.
   546. The  uterus  is  covered externally  with  perito-
naeum ; its  internal  cavity is small, and lined,  especially
at the fundus, with a soft and very  delicate spongy  mem-
brane, which is  composed, according to some, (92) of co-
lourless arteries and veins, (92) and,§ according  to  others,
of lymphatics. ||
   547. With respect to its muscularity, asserted  by some^J
and denied by others**, I may remark, that  I have never
yet discovered a true muscular fibre  in  any human uterus
which I have ever dissected, whether impregnated or un-
impregnated, recent or prepared; but it must be allowed,
that the fibres, termed by  some muscular, have qualities
very different from  any others observable in  the system.
I  am daily more convinced  that the  uterus  has no true
irritability,  (301) but a vita propria, (42) correspondent
with  the peculiar  motions  and functions of the  uterus,
  * Id. De Morbis Peritonai. tab. i. ii.
  f Mascagni. tab. xiv.
  \ Walter's Tab. Nerv. Thorac. et Abdom. tab. 1. J. F. Osiander's
Commentatio premio Regio  ornata, qua edisseritur uterum nervos habere.
Goett. 1808, 4to.
  § Ferrein in the Mtmoires de I*Acad, des Sc. de Paris. 1741, p. 375.
  || Mascagni. 1. c. p. 4.
  If See v. c. Sue in the Mem. pre'sente's, vol. v.
  L. Calza. in the Aui delV Acad, di Padqva. T. 1. u.
  *•  Walter.  Betracht. uber  die  Geburstheile  des vseibl. Geschl. p.
25, sq.
  Chr  H. Ribke. uber die Structur der Gebuhrmutter. Berl. 1793. 8vo.
but chiefly J. F. Lobstein, Magasin Encyclopedique redig( par Miliin.
vol. xlix.  1803. T. 1. p. 357, sq. 
302     OF THE GENITAL FUNCTION OF WOMEN.

which are not referrible to any  properties common to the
similar  parts, (39-41) and  which appeared to the ancient
physicians and philosophers  so peculiar, that the uterus
was by  them  denominated  an  animal  within an  ani-
mal.* (C)
  548.  Ftorn the angles of the roof or fundus of the ute-
rus  arise on each  side  the  Fallopian  tubes,]  narrow and
tortuous canals, running in  the upper part of the dupli-
cature of the broad ligaments,  similar in texture  to  the
vagina,  but internally destitute  of rugae, and lined by a
very soft and delicate spongy substance.
  549.  The extremity which opens into the abdomen is not
only larger than that which  opens into the uterus,  but is
surrounded by  laciniated or  digitated fimbria, singular
and elegant in structure, which  are  probably of  great im-
portance in conception, since they appear to become tur-
gid as well as  the  tubes themselves, during the venereal
cestrum, and to embrace the ovaria over which they lie.
  550. The ovaria,  or,  as they  were termed previously
to the time of Steno,! the female testes,  are composed  of
a tough and  almost tendinous covering,  and a  dense and
closely  compacted  cellular   substance, which contains  in
each  ovarium  about fifteen ovula, called  Graafian, viz.
vesicles, or rather drops of  albuminous  yellow serum,
which coagulates like white of eggs, if the  recent ovarium
is plunged into boiling water.
  * I have treated of these points at large in my programma De vi vitali
sanguini deneganda, &c. Gott. 1795, 4to. p. 15, sq.
  f Fallopius. Observ. Anat. 197.
  ! Steno was the first who asserted that the testes of women were
analogous to an ovarium,  1667.  Elementor. Myologies  Specimen, p.
117, sqq. 
         OF THE GENITAL FUNCTION OF WOMEN.      303

   551.  Such an  albuminous drop appears to be what the
female contributes in the business of conception, and it is
probable, that, during the adult state, these drops become
mature in succession, so that they  one by one force their
way, and  finally  burst the covering of the  ovarium, and
are received by the abdominal extremity of the Fallopian
tube.
   552.  Besides the albuminous  drop which  escapes from
the ovarium, another fluid, improperly styled female semen
by the ancients,  is poured  forth during the venereal oes-
trum.   Its nature, source,  and quantity, are enveloped in
no less mystery than its office.*
                        NOTES.
   (A)  The Hottentot peculiarity  is a prolongation of the
labia.!
   (B) The various size of the opening of the vagina in
virgins  and women, and the various firmness of the or-
gans, must ever leave those in uncertainty,  who  can on
their marriage  indulge  in  sensual doubts.  We  read in
Hume,  that Henry the Eighth, who certainly had his share
of experience, boasted his discrimination; but an eastern
monarch, whose experience was infinitely  greater, confess-
ed his ignorance.
   The lovers of Italian  literature know how strictly natu-
ral is every description  of Boccacio's, and will recollect
  " Respecting this problematical fluid, see Carpus in Mundinum,
p. cxcviii. sqq. and cccviij.
  Harvey, De Generatione Animal, p. 95.
  De Graaf, De Mulierum Or ganis, p. 194.
  t LeVaillant, Voyage dans PInterieur d'Afrique, Dr. Somerville, Med.
Chr. Trans. 1816. 
304     OF THE GENITAL FUNCTION OF WOMEN.

his story of the daughter of the Sultan of Babylon, " Essa
che con  otto nomini forse dicemilia volte giacuta  era,  a
lato a lui (al Re del Garbo) si concio, per pulcella, e fece
gli credere, che cosi fosse."*
  C.  The  muscularity  of the uterus is  allowed by  Mal-
pighi,  Morgagni,  Mery, iittre, Astruc,  Ruysh, Monro,
Vieussens, Haller, &c.
  Mr. Charles Bell  has a  paper in the fourth volume of
the Medical and  Surgical Society, which  it is necessary
to quote freely, in order to give an accurate description
of the muscular structure of this organ.
  " The muscularity of the uterus is proved by direct ocu-
lar  demonstration of the fibres in dissection, by the thick-
ness of the fibres corresponding with their degree, of con-
traction,  by the visible action of the human uterus during
life, by the resemblance of the laws of its contraction, (as
felt and as perceived  in  its  consequences)  to those which
govern the contraction of other hollow viscera, and, lastly,
by the vermicular and intestinal motions of the uterus, as
seen in experiments upon brutes."
  " The most  curious  and  obviously useful part of  the
muscular substance of  the  uterus  has been overlooked ;
I mean the muscular layer of fibres which covers the  up-
per segment of  the gravid uterus.  The fibres arise  from
the round  ligaments, and regularly  diverging, spread over
the fundus, until  they unite and form the outermost stra-
tum of the muscular substance of the uterus."
  " The substance of the gravid uterus is powerfully and
distinctly muscular ;  but the  course of the  fibres is here
less easily  described than might be  imagined.   Towards
the fundus the  circular  fibres  prevail; towards  the orifice
the longitudinal fibres are the most  apparent; and, on the
* Decamerone, vol. 1. 
         OF THE GENITAL FUNCTION OF WOMF.N.      305

whole, the most general  course of the fibres is from the
fundus  towards the orifice.   This prevalence of longitu-
dinal fibres is  undoubtedly a  provision for diminishing the
length  of the  uterus, and for drawing the fundus towards
the orifice.   At the same time these  longitudinal fibres
must  dilate the orifice,  and  draw the lower  part of the
womb over the head of the child."
   " In making sections  of the  uterus  while  it retained its
natural  muscular contraction,  I  have  been  much struck
in observing how entirely the blood vessels were closed
and invisible, and  how  open and distinct the mouths of
the cut blood  vessels became,  when the same  portions of
the substance of the uterus were  distended  and relaxed."
" A very principal effect of the  muscular  action of the
womb is the constringing of the  numerous  vessels which
supply  the  placenta, and which must  be ruptured when
the placenta is separated from the womb."
   " Upon im erting the  uterus and brushing off the deci-
dua, the muscular structure  is  very distinctly  seen.  The
inner  surface of the fundus consists of two  sets of fibres,
running in concentric circles  round the orifices of the Fal-
lopian tubes.   These circles at their  circumference unite
and mingle, making an  intricate  tissue.  Ruysch, I am
inclined  to  believe, saw the circular fibres  of one  side
onl\ ,* and not adverting to  the  circumstance  of the Fal-
lopian tubes opening in  the  centre of  these fibres, which
would have proved  their lateral position, he described the
muscle as seated in the  centre of the fundus uteri.  This
structure of the inner surface of the fundus  of the  ute-
  • Discovered by Weitbrecht, and first accurately observed  by Dr.
Hunter.
                          Rr 
306      OF THE GENITAL JUNCTION OF WOMEN.
rus i3 still adapted to  the  explanation of Ruysch,  which
was,  that this produced contraction and  corrugation  of
the surface  of the  uterus, which  the placenta not partak-
ing of, the cohesion of the surface was necessarily broken."
  " Further, I have observed a set of fibres of the inner
surface  of the uterus which are not described.  They com-
mence at the centre of the last described muscle, and hav-
ing a course  at  first in some degree vorticose, they de-
scend in a broad irregular band towards  the orifice of the
uterus.   These  fibres  co-operating  with  the  external
muscle  of the uterus, and with the general  mass of fibres
in the substance  of it,  must tend to draw down the fun-
dus and lower segment of the uterus over the child's  head."
  " I have not succeeded in discovering  circular fibres  in
the os tunicse  corresponding  in place and office with the
sphincter of other hollow viscera, and I am therefore  in-
clined to believe, that,  in the relaxing and opening of the
orifice of the uterus, the change does not result from a re-
laxation  of  muscular fibres surrounding the orifice.  In-
deed, it is not  unreasonable to conceive,  that the contents
of the uterus are to be retained during  the nine  months of
gestation by the action of a sphincter muscle.   The loosen-
ing of the orifice, and  that  softening and relaxation which
precede labour, are quite unlike the yielding of a muscular
ring." 
OF  THE MENSTRUA.
307
SECT.  XXXVIII.
OF THE MENSTRUA.
   553. An  important,  and  indeed  the  most  frequent
function of the uterus, is to afford a menstrual fluid during
about thirty years,—a law imposed upon no other species of
animal.*—Woman, in the words  of Pliny,  is  the only
menstruating animal—The females of no nation,  hitherto
explored,  are exempt  from this law,! since  it is  among
  • Most writers upon Natural History, and among the rest Buflfon,
allow the existence of menstruation in other animals, especially in the
simiae.  But, after carefully observing the females of the species of
simiae mentioned by him, (v. c. of the  simia sylvanus and cynomo gus,
the papio maimon, &c.) for a number of years, I easily discovered that
these supposed catamenia in some did not occur at all, and in others of
the very same species were merely a vague and sparing uterine he-
morrhage, observing no regular period.
  j- There is hardly occasion, at present, to refute the unfounded asser-
tion, that in some nations, particularly on the continent of America, the
women do not menstruate.  This opinion  appears to have originated
from the circumstance of the Europeans, who visited those countries,
and saw innumerable women nearly naked, never finding any menstrual
stains upon them.  For this there might be two reasons.  First, the
American women are,  by a happy  prejudice, regarded as infectious
while menstruating, and remove from society, to the advantage of their 
308
OF THE MENSTRUA.
the  requisites in the female sex, for the propagation of
the species.
  554.  The commencement of  this function usually occurs
about the  fifteenth  year,  preceded by  symptoms of ple-
thora,  by a sense of heaviness  in the chest, and of tension
in the loins, by lassitude of the limbs, &c.   From the first
of these  symptoms, a reddish fluid generally  flows  from
the genitals, becoming by  degrees  of a more  bloody co-
lour, and at length completely so.   This has a  peculiar
odour, coagulates but imperfectly, and differs  also in other
respects from blood.   It continues to  flow slowly for some
davs, and  the unpleasant  symptoms  above  described in
the mean time cease.
  555.  This red discharge returns  after this period about
every four weeks, and continues about six  days, during
which time a healthy woman is supposed to lose, perhaps,
from five ounces to half a pound of blood.
  556.  This  action  is usually  discontinued  during preg-
nancy or lactation.   It  entirely ceases after existing about
thirty years ;  that  is, in our climate, about the forty-fifth
year.
  557.  By  some, the vagina, by others, and  with  more
probability, the uterus, is considered the source of this dis-
charge.  Arguments adduced  against the latter  opinion,
from the examples of women menstruating although preg-
nant, or having the  uterus imperforate or prolapsed, prove
only the extraordinary compensating  powers  of  nature,
who employs  new  ways,  when the customary  are im-
health, into solitary huts.  Again, their extreme cleanliness, and the
modest position in which they place their limbs, would prevent any
vestige of the catamenia from being observable, as  \dr. Van Beikel
expressly states in his Reisen nach Rio de Berbice und Surinam, p. 46. 
                    OF  THE MENSTRUA.                309

peded.   On the other hand, the dissection of many women
who  have  died  during  menstruation  has  discovered  the
cavity  of the uterus bedewed with the catamenia.*  I  say
nothing of  the   a  priori argument,—that the  purpose  of
menstruation  is probably to  render the womb fit for preg-
nancy,  and   for  nourishing  the  fcetus.f   For the same
reasons, the arteries, rather than the veins, appear to be the
source of the discharge!
   558. The  investigation  of the causes  of the periodical
return of this hemorrhage is so  difficult, that we can obtain
nothing beyond  probability, and shall not  dare to offer  any
thing merely conjectural.§
   The proximate cause  is supposed to be a loeal\\ plethoric
   * See, for example, Morgagni's Adv. Anat. 1. tab. iii. M. M. M.
   f L.  H. Chr. Niemeyer,  Demenstruationisfineetusu.  Goit. 1796,
 8v-o.
   \ J. Fr. Osiander, on the contrary, argues on the side of the veins.
 Diss, de fiuxu menstrua  atque  uteri prolapsu.   Gott. 1808, 4to.
 p. 14.
  § \mong other writings,  Abr. D'Orville's Disquisitio causie menstrui
fiuxus (Pracs. Hallero) may be consulted by those who feel interested
 with this enquiry.   Also,  Gisb. Verz.  Muilman.  An ex celebrata
 hactenus opinione de plethora universale <oel pardculari vera fiuxus menstrui
 causa explicariposstt ? L. B.  1772, 4to.  Artd Theod. Traug. Jaehkel.
 (Praes. Krause) Actio/'. fiuxus menst. Lips.  1784, 4to.
  || The universal plethoric  orgasm, as it was  termed, which some
 formerly regarded as the cause of menstruation, has been  long since
 refuted  by more enlightened physiologists.  To the arguments of the
 latter, Imaybe permitted to add the instance of the celebrated Hungarian
 sisters, who, from monstrous formation, were united together (63 Note).
 Although the same blood flowed  n each, on account of the union of the
 abdominal blood vessels at the loins, they  differed frequently, both in
 the period and the quantity of their menstruation. 
310
OF THE MENSTRUA.
congestion ;—an opinion, with which the symptoms preced-
ing menstruation, and  the abundance  and nature  of the
Uterine vessels, agree very well.
  Among the remote causes may be enumerated the erect
posture  peculiar to the  human race, the peculiar  paren-
chyma of the uterus, and its vita propria.
  It will be better to confess our ignorance of the cause of
its periodical return, than to indulge in  vain hypotheses:
all the periodical phenomena of health and disease,  which
continue more than twenty four hoursi are among the mys-
teries of animal nature. 
OF  CONCEPTION AND PREGNANCY.        311
        SECT.  XXXIX.


OF  CONCEPTION  AND PREGNANCY.
   559. We now come to the functions for which the geni-
tal organs are given us—to conception, and the propagation
of the species—in treating which, we shall first merely de-
scribe the phenomena which are observed in  that admirable
and  truly divine  process,  and  afterwards investigate the
powers by which they are produced.
   560. In the first place, it is  worthy of remark, that the
human race, unlike most animals, does  not copulate at cer-
tain  periods of the year,* but that,  with it, every  season is
equally favourable to the flame  of love.
   561. When a woman admits the embraces of a man,!
and both burn with that animal  instinct  which is  superior
to all others  in  universality and  violence,  the uterus,  I
conceive, swelling with a kind of inflammatory orgasm,!(A)
  • Unless the observation, first made by Wargentin, in Sweden, that
Hiere is a greater proportion of births in September, which corresponds
with the preceding December, be considered as relative to this point.
Vide Sioenst.  Vetentk. Acad. Hadlingar, 1767, vol. xxviii. p. 249 et seq.
  f Of the various circumstances of this act, I have spoken in my work
De gen. hum. variet. nai. p. 17etsq. ed. 3.
  \v. the two instances seen by Ruysch, of uteri immediately after
impregnation.  The one of a common woman,  murdered by her para-
mour immediately after connection.   Adversar. Anat. Medico Chirurg. 
 312         OF  CONCEPTION  AND PREGNANCY.

 and animated  by its  vita  propria  (547),  draws  in, as  it
 were, the semen ejaculated by  the male,*  and  iippears to
 pour forth a  fluid of its own  against it (552) ; the  tubes
 become rigid, and  their fimbriae  embrace the ovaria, in
 one  of which  a  ripe  Graafian  vesicle  bursts  like  an
 abscess, and its albuminous drop of fluid,  being absorbed
 by the  abdoTiinal opening of the tube, is conveyed  to  the
 womb.
   562. After the escape of this drop from the ovarium, the
 lips of the womb are closed by an external cicatrix, and the
remaining vascular membrane is converted into a corpus lu-
 teum.]  This is at first hollow, and full, as 1 think, of a plas-
tic lymph,  whi;h  in progress  of  time becomes  a fleshy
nucleus,! surrounded with a thick cortex, remarkably vas-
cular. § (A)
 Dec. i. tab. ii. fig". 3.  The other of a married woman, impregnated
 a few hours pre\ious v, : nd killed in the ac* of adultery by her husband.
 Thesaur. Anat. vi. p. 23 et seq. tab. v. fig. 1.
  * If we consider the impetus with which the semen is emitted, and,
 as it were, swallowed by the uterus, and how small a quantity is proved,
 by experiments on animals, to be sufficient for impregnation, we shall
 be able to explain  those well established  cases of conception,  where
 the hymen was impe.forate—cases brought forwards in support  of the
 existence of a seminal aura.
  ■\ See J.  Chph. Kuhleman s's Observat. circa ncgot. generat. in ovib.
factx. Gotting.  1753, 4io.  c.f. ae.
  \ See VV. Hunter's Anatomy of the gravid uterus. Tab. xv. fig. 5.
 tab. xxxix. fig.  3. tab. xxxi. fig. 3.
  § It is a celebrated question,  of great importance, both in physiology
 and  forensic medicine,  and much agitated in late years,  whether a
 corpus luteum is the consequence of a fruitful coition alone, and there-
 fore  an infallible sign of conception, or whether it can orcur indepen-
 dently of coition, and may therefore exist in virgins.  I trust  that I
 have settled this dispute according to the truth, and have shown the 
OF CONCEPTION AND PREGNANCY.
313
   563. After impregnation,  the  canal which  runs  along
the cervix of the  uterus is thoroughly  closed, especially
towards its superior or internal orifice (544), so that super-
lactation, properly  so called,*  cannot naturally  take place.
There  are scarcely  any  constant and infallible  signs,  by
which the woman  herself can be very certain of the  changes
which occur within during conception.!
   564. The internal surface  of the  uterus becomes lined
with  plastic, and,  as it were, inflammatory lymph (15),
which  forms the  tunica  caduca,  or decidua of  Hunter.^
 conditions under which it may occasionally take place even in virgins.
 Specimen physiologic comparattx inter animantia calidi sanguinis vivipara et
 ovipara, in the Commentat. Soc.'Reg. Scientiar. Gotting. vol. ix. p. 109
 et seq.
    • That different conceptions may occur from the repetition of coition
 after very short intervals, is proved  b^^he  instances of adulterous
 women, who have brought forth twins r^Smbling different fathers in
 the colour of their skin : viz.  of black women who have brought forth
 a black and a mulatto, and of European women who have brought forth
 a white and a mulatto. (B)
    f Ad. El. Siebold, De diagnosi conceptionis et graviditatis tape dubia.
 Wirceb.1798.4to.
    Gm. Theoph. Kelch. De symptomatibus et signisgraviditatis earumaue
 eausis. Regiom. 1794, 4to.
    ! Aretaeus Cappadox (De Causis et Sig. Morb. Diutturn. 1. 11. c. ii.
 p. 64 et seq. Boerhaave's edition) seems the first who gave a true ac-
 count of the origin of this membrane, the more accurate knowledge of
 which we owe to Wm. Hunter.
    After the revival of anatomy, Fallopius restored the knowledge  of it.
 Observ. Anat. p. 207.  "The chorion is either the chorion simply so
 called, or the spongy, tomentous, fungous, filamentous, the reticulated of
 the moderns, the involucruvi membranaceum of Albinus."   Kuysch,  so
 far as my knowledge extends, gave the first plate of it.  Thes. Anat.
?. tab. i. fig. 1. F. B. C. G.
                            Ss 
$14        OF CONCEPTION AND PREGNANCY.
This is said to consist  of two lamina?, the crassq investing
the uterus, excepting at the orifices of the tubes and of the
canal of the cervix ;*  the  other being, after  the  ovulum
begins to be formed and to take  root in  the decidua,  con-
tinued over the rest  of the  ovum, as the peritonaeum is
continued over the abdominal viscera, is denominated the
caduca refexa.]
   565.  The ovulum] is produced before the embryo which
it  is intended to receive, but scarcely begins to be formed
before the  second  week  from conception.  Previously to
this period, I  very much  doubt  whether any vestige of
human conception has ever hfcn visible.
   566.  This ovulum consists, besides  the external acces-
sary covering afforded by  the caduca of Hunter, of  two
proper velamenta or membranes.
   Of an exterior,—the chorion^  of the moderns;  the ex-
ternal  surface  of which is, from the  first, nearly covered
with  inexpressibly  b^ptiful  knotty flocculi; whence it
has been called the flocculent, leafy,  or mossy,  chorion.
By means of these flocculi, which are the rudiments of the
foetal portion of the future placenta, the  ovulum takes  root,
as it were, in the uterine decidua (564).
  * W. Hunter, 1. c. tab. xxxiv. fig. 3—6.
  t See B. S. Albinus' Annot. Acad. L. i. tab. iii. fig. 1. e.
  VV. Hunter, 1. c. tab. xxxiii. fig. 1—4.
  \ Kespecting the membranes of the ovulum, and their  connection
with the uterus and embryo, vide J. F. Lobstein, Uber die Erniihrung
desfatus. Halle. 1804. 8vo.
  § 'I he Membrana ■ edia of Rouhault, Haller,  &c.  For the various
synonyms and homonyms of the membranes of the, ovum, consult Hal-
ler's Elem. Physiol. Vol. viii. P. 1. p. 194. sq. and Tabarran's letter
to Bartoioni,iii the Aui di Siena. T. vi. p. 224. sq.               ^ 
OF CONCEPTION AND PREGNANCY.
315
   Of  an interior, styled  amnion, possessing no blood ves-
sels (5), delicate, but remarkably tough.
   567. These two proper membranes of the ovulum differ
very much from each other in size the  first week after
the formation of the ovum ; the chorion  appears a large
bladder, to which the amnion, like  a much smaller blad-
der, adheres  in  that part only  which nearly corresponds
with  the centre of the external flocculent surface of the
chorion.
   The remaining space between the chorion and  amnion
is filled  by a clear  water, which may be called  the liquor
chorii, of doubtful origin and short duration.
   For sjnce the amnion increases more rapidly than  the
chorion, and  approximates to  the  latter even during  the
first months after conception,* in proportion to its approxi-
mation must this fluid necessarily be absorbed.
   568. The internal membrane of the ovum is filled, from
its  first formation (565) to the last moment of pregnancy,
with the liquor amnii,]  an aqueous  fluid,  of a  yellowish
colour, nearly inodorous, of a  bland and  scarcely saltish
taste,  commonly  thought nourishing,  and  compared  to
albumen, from which, however, more accurate  investiga-
tion proves it to differ considerably-!
   Its source  is  doubtful, and  cannot be  referred  to  the
  • See Hunter's figures (imaginary indeed) 1. c. tab. xxxiv. fig. 9.
8. 7.
  f Paul. Scheel, at the end of his Commentat. de liquoris amnii asperx
arterix ftttuum human, natur. et usu. Hafn. 1799, 8vo.
  C. H. D'Zondi. Supplementa  ad anat. et physiolog. potissimum com-
paratum. Lips. 1806, 4to.
  | Steph. J. Van Geuns, De natura et utilitate liquoris amnii.  Ultraj.
1793, 4to. 
316
OF CONCEPTION AND PREGNANCY.
foetus or umbilical chord, since it exists  in abortive ovula
containing neither.
   Its  quantity is inversely  as  the  size  of the  foetus.
Hence we may conjecture, that its use is rather to defend
the foetus while nearly  gelatinous and most liable to suf-
fer from external injuries, than  to  afford  nourishment.
That the portion of  the fluid which  occasionally, although
rarely, and  therefore not naturally,  enters the stomach of
the foetus, is not  destined to nourish it, is evident from
the nature of this fluid,  and from the state of the  chylo-
poietic  system  of the foetus:  to  omit arguments deduced
from acephalous foetuses, &c*
   569.  The embryo, which swims in  this fluid,  suspended
by  the  umbilical chord, like  fruit by its stalk,  begins to
be  formed from  about the third  week  after  conception :!
at first it appears to  be of  a rather globular  shape, resem-
bling a  little bean or kidney,  from  which  the  rudiments
of the extremities grow, and  the face is at length formed,
and s. p«!
  * I trust  no one will  adduce,  in objection,  accounts of foetuses
destitute of umbilical vessels, who has read those accounts with any
attention.
  f There is no occasion  in our times to refute the false remarks and
figures  given by Mauriceau, Kerckring, and others, of foetuses, one or
a few days old.
  The reasons of my fixing upon this term, I have explained at large
in the Median. Bibliothek. vol. ii.  p. 673, sq.   How remarkably this
was afterwards confirmed by fact, will be found in the same work, voU
iii. p. 727.
  Those who have not an opportunity of inspecting the fragile primor-
dia of our race muy consult the excellent plates in Ruysch's Thesaur,
Anat. vi. tab. ij. fig. 2. 3. 4. 5. 8. 10. Thesaur. x. tab. iii. fig. 1.
  Also B.  S. Albinus' Annotat. Acad. L. i. tab. v. fig. 4. 5. 
            0» CONCEPTION AND  PREGNANCY.         317

   570. By nature, woman is uniparous, conceiving but one
foetus.  Frequently, however, she produces twins, the pro-
portion of which to single births, Siissmilch estimates as 1 to
70.*   In these cases, each child has usually its own amnion,
but there is a common chorion.!
   571. The medium of connection between the mother and
the child  are,  the umbilical  chord, and the placenta into
which it is distributed.
   S72.  The umbilical  chord, which appears  coeval with
the embryo, varies  exceedingly  in  length and thickness,
in the place  of its insertion-into the  placenta, in its  va-
ricose knots,  &c.   It  generally   consists of three  blood
vessels twisted  spirally together, viz. a  vein  running to
the liver of the foetus, and two  arteries  arising from its
internal iliacs  or hypogastrics.   They  are separated  from
each other by cellular  septa of various directions,! and are
  Trew in the Commerc. Litter. Noric. 1739. tab. iii. fig. 4. 5.
  Abr. Vater's Mus. anatom. propr. tab. viij. fig. 2. 4. &c.
  And,  Instar Omnium,  Sosmmering's Icones  Embryon  Humanor.
Francof. ad Moen. 1799. fol.
  * This proportion is  not very constant, and there is some national
variety in this respect. (C.)
  Egede expressly mentions the infrequency of twins among the Green-
landers, in his Descr. du  Grbnland, p. 112.
  Their remarkable frequency among the people of Chili is asserted by
Molina, in his Saggio sur la Storia Naturale del Chili, p. 333.
  f See Denman's Engravings, tending to illustrate generation and parturi-
tion. Lond. 1787. fol. tab. ix.
  Twins are very rarely contained in a common amnion.  Vide J. de
Puyt, in the Verhandel. der Zeeuiusch^Genootsch. te  UHssingen. T. ix. p.
423, sq.
  \ W. Noortwyk. Uitri Humani Gravidi Anatome,  tab. iii. fig. 5.
6.7. 
318         OF CONCEPTION  AND PREGNANCY.
throughout narrowed internally  by nodules, or the quasi*
valves of Hoboken.*
   They are collected into a chord  by means of a cellular
membrane, which is full  of a singular very limpid  fluid
called Whartonian,   resembling  gelatine   in  appearance,
and is surrounded externally by a continuation of the am-
nion.
   573. At the part of the chord which is united to the
foetus, there runs the urachus,] which arises from  the  fun-
dus of the urinary bladder, and lies between the two um-
bilical arteries.   In  the human subject, it  is pervious  but
for a very short  distance, • and,  indeed,  soon  disappears
altogether.  In other mammalia it leads to the  allantoid,!
which is universally acknowledged to be absent  in the  hu-
man foetus.   For I think that the  problematical vesicula
umbilicalis, found in human ovula   between  the  chorion
and amnion,§  is  not analogous  to  the allantoid,II  but to
the tunica erythroides, found in  the ova of some mamma-
lia, and  to the vitellary  sac  of the  incubated  egg.   It
is  found  in healthy  human ovula, the  second  or third
  * Hoboken. Anatome secundin. human, repetita. p. 522, sq. fig. 38.
 39. 40.
  This structure is further displayed in the arterial branches of the pla-
 centa by Aug. Chr. Reuss, in the Nov. Observ. circa Structur. Vasor. in
 Placenta Humana. Tubing. 1784, 4to.
  ! J. Noreen De Uracho. Gotting. 1749, 4to.
  Ph. Ad. Boehmer on the same,  at the end of his Anatome ovi hum.
fcecund. sed deformis. Hal. 1763, 4to.
  ! Vide  Fabr. ab Aquapendente. De  Formato Feetu.  tab. xii. xiii.
 xiv. xvii. fig. 27. xxv.
  § Vide the Commentat. Soc. Reg- Sc Gottingens- vol. ix. p. 128. fig, 1.
  || Among the moderns who have compared it to this, is J. F. Lob-
 stein, I. c. uber die Ern'dhrung des Foetus.  C.  H. D'Zondi. Supplem-
 ad Anat. et Physiol. 
               OF  CONCEPTION AND  PREGNANCY.      319

month from conception, too frequently and of too constant
an  appearance to be regarded  as accidental, morbid,  or
monstrous.*
  57'4>. The blood  vessels of the chord pass to the pla-
centa, of  whose origin  from  the flocculent surface of the
chorion united  to the decidua crassa, we  formerly  spoke.
Hence we  discover how  the substance of the placenta is
double—the uterine portion derived from the decidua and
forming a spongy parenchyma:  the foeval arising  from  the
umbilical vessels distributed on the chorion.   The increase
of the ovulum is irregular, so that the  smooth part of the
chorion grows  more rapidly  than the  flocculent:  conse-
quently, the size of the placenta bears a greater propor-
  • The opinions both respecting the natural constancy of the vesicula
umbilioalis, and its analogy to the tunica erythraides, I originally, as far
as I know, proposed upwards of twenty years since, in the first  edition
of these Institutions (1787), and in my Specimen Physiologia: Comparats:
(1788), formerly quoted-,
  The connection of this vesicle with the intestinal canal of the embryo,
and indeed with the appendix vermiformis of the caecum, is shewn by
Laur. Oken in his, and Diet.  G.  Kieser's Bcytr. zur Vergleichenden
Zoologie, &.c. Fasc. 1. ii. Bamberg, 1806, sq.
  See likewise Kieser's Ursprung des Darmkanals aus der Vesicula Umbi-
licalis, dargestellt im Menschlichen Embryo. Goett. 1810, 4to.
  But, on the contrary,  Fr. Meckel shews it to be united with  the di-
verticulum of the small intestines  (Diverticulum Littrianum) in his
Beytr. zur vergleichenden Anatomic Vol. 1. Fasc. 1. Lips. 1808, p. 93;
and more fully in Reil and Autenreith's Archiv.fur die Physiologic Vol.
ix. p. 421.
  Consult, among others, W. Hunter, Anatomical Description of the
Human Gravid Uterus (a posthumous work, edited by Matthew Baillie).
Lond. 1794, 4lo.  p. 40, sq.
  B. N. G. Schreger's letter to Soemmering, De functions placenta
uterinx. Erlang. 1799, 8vo. 
320        OF  CONCEPTION  AND  PREGNANCY.
tion to that of the ovum, the shorter the period which  has
elapsed since conception, and  a smaller, as the period of
labour approaches.
   As pregnancy advances, its texture becomes more com-
pact, sulcated, and lobular on its uterine surface,  and
more smooth on its interior surface, which is  covered by
the amnion.   It varies greatly in  size, thickness,  figure,
and situation, or place of attachment to the uterus ;  ge-
nerally it adheres to the fundus ;  it is destitute of sensibili-
ty and true irritability.
   575.  Although all agree that the placenta is the chief in-
strument in the nourishment of the foetus, the true mode of
its operation, and its mutual relation to  the uterus and foetus,
have  given  rise to great controversies  in modern  times.
After all, the truth  appears to be this,—that no anastomosis
exists between the blood vessels of  the uterus and of the
chord : but that the  oxygenized blood, which proceeds from
the uterus to  that portion of the placenta which was origi-
nally the decidua crassa, is absorbed by the extreme radi-
cles of the  umbilical vein distributed  upon  the  flocculent
chorion, and carried to the great venous trunk of the chord;
the carbonized blood returning from the foetus, through the
umbilical arteries, being poured in  the same manner into
the substance of the  placenta, is absorbed by the venous
radicles of the uterine portion of the placenta, and returned
to the uterus.
  This account is supported  by  very careful but fruitless
attempts to  inject the  umbilical by means  of  the uterine
vessels, and the uterine by  means  of  the umbilical; or to
tinge the  bones of the foetus with red, by giving madder
to the mother during pregnancy.  It is also  confirmed  by
the difference observable between the blood of the mother
and foetus. (D) 
            OF CONCEPTION AND PREGNANCY.        32}

   576.  During the progress of pregnancy, while the foetus
and secundines are increasing,  the  uterus of course under-
goes important changes, not only in its size, but situation,
figure, and especially in its texture,  which is considerably
changed both in regard to its  blood vessels and the inter-
vening parenchyma, from the constant and great  congestion
of fluids which occurs.
   In proportion as the uterus  increases, the  blood vessels,
from being tortuous and narrow, become more straight* and
capacious, and  the veins, near the termination of pregnancy,
acquire so great a bulk! as to have been taken for sinuses
by some anatomists.
   The parenchyma becomes gradually more thin and lax,!
especially in the part nearest the ovum, so that although the
gravid uterus is very thick, particularly at its fundus,  and in
a living and healthy woman is turgid with blood and replete
with vital energy, nevertheless it is soft, and its general na-
ture, especially after death, when, as  Arantius  long since
remarked, it almost appears lamellated in advanced preg-
nancy ,§ extremely different from the firm and compact sub*
stance of the unimpregnated uterus.
   577.  The remaining important changes||  of the gravid
uterus,  as well as those still more  remarkable  which oc-
cur to the ovum  and foetus,  we shall briefly relate in the
  • v. W. Hunter. Anat. Uteri Gravidi, tab, xvi.
  f Ibid. tab. xviii.
  ! v. B. S. Albinus' Annotat. Acad. i. ii. tab. iii. fig. 2.
  § Arantius' book De Humano Feetu. p. 5, sq. 1579. Compare  B. S.
Albinus' Tab. Uteri Gravidi, ii.
  || Among other works, consult J. Burns's Anatomy of the Gravid ty*
rvs.  Glasgowi 1799, 8vo. a work carefully and faithfully executed
                           Tt 
322
OF CONCEPTION AND PREGNANCY.
order of the ten lunar months, according to which pregnan-
cy is at present very conveniently calculated.
  578. As the uterus  immediately after impregnation al-
ways becomes  turgid,  (561) so, increasing from that pe-
riod in bulk  and weight, it descends into the upper part
of the vagina, still  retaining its  former figure during the
first three months, except that, perhaps, its fundus becomes
a little more convex, and  its anterior  portion somewhat
recedes from the posterior, and  that its cavity, before ex-
tremely small and  nearly triangular, becoming expanded
by the fluids of the ovum, accommodates itself to their sub-
globular form.
   The ovum itself,  which, about the termination of the first
month, is of the size of a pigeon's egg, and possesses both de-
cidua separate from each other, and the minute amnion se-
parate from the larger chorion, commonly attains, near the
end of the third month, the size of a goose's egg; the de-
cidua reflexa then closely approaches to the crassa, and  the
amnion to the chorion ; the  former is filled  with the fluid
which bears its name, and defends from  the pressure of the
womb the tender embryo, now very small in proportion to
it, scarcely, indeed, equal to the size of a young mouse, and
variable and  dependent* in situation.
   579. From the fourth month,  the  uterus becomes more
oval  or  subglobular,  and  its  neck gradually  softening,
shortening, and almost disappearing, or rather  distending
laterally, it tends upwards, and begins to rise  to the supe-
rior part of vthe pelvis.   At the same time  the  tubes ascend
with the convex fundus of the womb, and are extended
and elongated, but adhere to  the sides of the uterus so
* v. Doeveren. Sptcim. Observ. Academ. p. 104, sq. 
            OF CONCEPTION AND PREGNANCY.        323

 firmly,  that  half of  their length only is separate from
 it;  and,  at  first sight,  they appear to  arise  from  the
 middle  of the uterus,—a circumstance  which  gave occa-
 sion  to an erroneous opinion of the enormous  increase of
 the fundus of this organ.  After this period, the foetus ac-
 quires a size more  proportional to  the capacity  of  the
 ovum,  and becoming,  at the  same time, conglobated to-
 gether, acquires a more fixed situation, which it preserves
 to the end of pregnancy ; the head is inclined to  the chest,
 and the back bent, and generally rather opposite  to one side
 of the mother.
   580. In the middle of pregnancy,—at  the end of the fifth
 month, so great has  the size of the uterus become, that its
 fundus is nearly between the navel and pubis, and pregnan-
 cy becomes externally evident.  From this period, the foetus,
 by its motion, is generally more distinctly perceptible to the
 mother:  this circumstance, however, occurs at  no definite
 time.
  581.  During the remaining five lunar months, the uterus
 and foetus continuing to increase, the fundus of the former
 reaches the umbilicus about the sixth month; after the eighth,
 having risen higher,  it approaches  the scrobiculus cordis.
 In the mean time, the cervix is gradually obliterated, flatten-
 ed, and attenuated.
  582. In the tenth month, the uterus,  overwhelmed, as it
 were, with its own bulk, being eleven inches  in  length and
 nine or more in breadth, begins to subside.
  Each  decidua, but especially  the  reflexa  adhering to
the chorion, having  for  many  months been growing thin-
ner,   now  almost appears  a  net-work   of short  white
fibres.*
* On the various appearances of the decidua during the latter half of 
324       OF CONCEPTION AND PREGNANCY.

   The larger diameter of the placenta is now  nine inches ;
its thickness one inch ; its weight one pound or upwards.
  The length of the  umbilical chord is  generally eighteen
inches or more.
  The weight of a common full  grown foetus is  usually
seven pounds ; its length about twenty inches.*
  The quantity of the liquor amnii is  too variable to be
defined $ but when the foetus is strong, it seldom exceeds a
pound.
                        NOTES.

  (A) The  important contents of this  and the preceding
paragraph demand farther attention.
  Several questions occur.   1. What is the state of the fe-
male organs during the vehemence of desire ? 2. How far
does the semen masculinum penetrate ? 3. Do the Graafian
vesicles burst from the influence of  the semen masculinum,
or merely from  the act of copulation, the semen impreg-
nating only the contents of the vesicles after their escape
from the ovaria ? 4. At what period do the Graafian vesicles
burst ?
  1.  Mr. Cruikshank, on  inspecting  the genitals  of a
female  rabbit  during  heat, observed appearances nearly
similar  to  those  described  by  Harvey, Graaf,  Ruysch,
pregnancy, consult W. Hunter. Anat. of the gravid uterus, tab. xxiv.
fig. 3, 4. tab. xxix. fig. 4, 5. comparing with these, tab. xxix. fig. 2.
  * This weight and volume are remarkably large in proportion to the
mother, if compared with those of the  offspring of many other mam-
malia.  But, notwithstanding this, woman is so far from producing the
largest foetus, in this respect, among the mammalia, that she is far sur-
passed by some, especially of the bisulca. 
OF CONCEPTION AND PREGNANCY.
325
 Diembroeck, &c*  He found them all prodigiously turgid
 with blood ; the vagina was absolutely  of a  dark mulberry
 colour, and on  the ovaria were prominent spots, which  in-
jection proved  to be  vascular, and which were  swollen
 Graafian  vesicles; the contents of the vesicles, however,
 remained  transparent:  the  Fallopian tubes  were also
 nearly black, writhing in  an extraordinary manner, hav-
 ing  a strong peristaltic motion, and embracing the ovaria
 with their fimbriated extremity so closely as to lacerate
 on an  attempt  to disengage them.!   These  observations
 were all  confirmed by my friend  Mr. Saumarez-!   Dur-
 ing copulation, this state of the organs  must be carried  to
 the highest pitch of intensity.
   2. Harvey could never detect semen in  the uterus after
 copulation.^  Nor De Graaf in  the vagina.||  Verheyn
 found  a large quantity in the uterus  of a cow, six hours
 after copulation.^} Galen  always discovered it in the ute-
 rus of brutes after copulation.**   Lewenhoeck, in the case
 of rabbits.   Ruysch  found it not only in the uterus, but in
 the  Fallopian tubes  of two  women killed  in#the*act  of
 adultery.!!   Postellus, Riolan, Carpus, and Cheselden, also
 believed they found it in the uterus.!!  Haller once found
 it in the uterus of a sheep, forty-five minutes after coition,§§
  •Boerhaave.  Prtelectiones Acadcmica, with Haller's notes, T.vi.
p. 113. sq.
  f Experiments, &c. by W. Cruikshank. Philos. Trans. 1797-
  ! A new system of Physiology, &c. by R. Saumarez, vol. i. p. 337
  § Harvey.  De Generatione, p. 228, &c.
  || Regn.  De Graaf. T. 1. 310.
  fl Verheyn, Sup. Anat. tra. 5. cap. 3.
  *• Galen, De semine. 1. i. c. 2.
  ft Ruysch. Thes. Anat. p. 90. tab. vi. fig. I.
  \\ Boerhaave's Protect. Acad. Haller's note to p. 182. t. 6
  §§ Haller.  Elcmenta PhysioL T. 8. p. 22. 
326
OF CONCEPTION AND PREGNANCY.
 and  Mr. Hunter is said to have seen  it in the uterus of a
 bitch which he killed while  united with the male, by divid-
 ing the spinal marrow.*   Haller very  justly remarks, that
 some of those who assert that they saw semen  in the  ute-
 rus, probably, saw mucus only.  He inclines, however, with
 almost all physiologists, to  the  opinion  that  the semen
 does enter the  uterus.   The length of  the penis, the force
 of  emission, the  existence of a bifid glans with two  orifi-
 ces  in the penis  of those  male  animals,  the females  of
 which have two ora  uteri,! are circumstances  of no little
 weight in favour of the  opinion, that the semen does pene-
 trate at least as far as the  uterus.  But this we shall pre-
 sently examine farther-!
  3.  Dr.  Haighton, the present lecturer on physiology and
 midwifery at Guy's  Hospital,  with the  view of ascertain-
ing whether it is necessary to impregnation that the semen
  * Saumarez. 1. c. p. 429.
  f Account of the structure of the Wombat, by Sir E. Home. Phil.
 Trans. 1798.
  ! Mr. Saumarez observed in two instances, when two hours and a
half only had elapsed after coition, and before  corpora lutea were
formed, globular, pearl-coloured bodies, as large as a pea's head, which,
on being squeezed, burst, and discharged, to some distance, a very
subtle fluid.  Dr. Haighton commonly met with them.  Whether these
were semen, having undergone some change, is uncertain.
  The  well known instances of conception without the admission of
the male organ into the vagina, on account of the great strength of the
hymen, are sometimes cited against the opinion, that the semen passes
beyond the vagina.  I can scarcely say with what weight, because the
most minute portion of semen is  sufficient to impregnate.  Spallan-
zani mixed three grains of frog's  semen with a pound  and a half of
water,  and, with this, fecundated nearly all  the numerous posterity
contained in the threads taken from the female ; and, after mixing
three grains with even twenty-two pounds of water, he fecundated
 ome.   Dissertations, vol. 2. p, 191.  English  translation. 
            OF CONCEPTION AND PREGNANCY.         327

enter the Fallopian tubes, made a riumber of experiments on
the effects of tying and dividing the tubes in  rabbits at dif-
ferent periods relative to coition.* The peristaltic action of
the tubes, and their adhesion to the ovaria during the vene-
real ardour, argue strongly in favour of the semen being con-
veyed  along them, because they can hardly be supposed to
begin to occur at this period for the purpose of conveying
the contents of the Graafian vesicle, as this does not burst
till a considerable time  after  copulation.  Dr.  Haighton,
indeed,says that these changes  in the tubes did not take
place in   his  experiments till long after  copulation  (48
hours),—till the ovaria were about to discharge into them
their vesicular  fluids.  In  this  he agrees  with Bartholin,
De Graaf, Schurig, Deswig  and Lang, who maintained,
like  him, that  the  semen, at least as far as examination
went, does not enter the tubes.f   But Mr. Cruikshank and
Mr.  Saumarez, two of the  latest experimenters, assert the
contrary  in the detail of their  experiments, and, as Haller
remarks of the  old  partizans,  the  negative experiments of
the former  cannot overturn the positive testimony of the
latter, " Eorum experimenta negativa non possunt affirman-
tium fidem  evertere:" Sbaragli, Verheyn,  Hartman,  and
Duverney, could find no change in the state of the tubes
at any  time, although  their negative  observations  are
completely  overthrown  by the positive  observations of
all others who have  enquired  experimentally  into the
subject.   Besides, the great  abundance of  blood  in the
genital organs, during the  sexual  ardour,  must cause the
tubes to enlarge and apply themselves to the ovaria: this, as
  • Experimental Enquiry, &c. by John Haighton, M.D. Philos. Trans.
1797.                                          «
  t Haller. Elem- Physiol, and notes to Boerhaave, 1. c. 
328
OF CONCEPTION AND PREGNANCY.
Haller mentions upon the authority of Hartsoeker, occurs
even  in  the  dead   body  by  means  of  injection.—Dr.
Haighton, however,  to  prevent the semen  from passing
along  the tubes,  divided one  of  them  in virgin rabbits,
and, after the wound was healed,  admitted the animal to
the male.   The  ovarium on this  side contained  corpora
lutea  equally  with the other,  proving  that  the Graafian
vesicles had burst, although the semen could not possibly
have reached the ovarium.*  No foetus, however, was dis-
coverable in any  instance: on the other  side,  foetuses
were  found equal in number  to  the  corpora lutea.   Dr.
Haighton concludes  that  impregnation  may  take place
without the advance of semen into the  tubes.  And his
conclusion is just, according to his test of impregnation,—
the escape of the contents  of a Graafian vesicle.   But I
apprehend this to be no more deserving the title of a test of
impregnation than the emission of the semen masculinum.
Impregnation is that change wrought by means of the  male
semen in the  contents of a Graafian vesicle, which ena-
bles them to become a foetus.  Now this was never effected
when the tube was divided: although the presence  of cor-
pora lutea proved vesicles to have burst, yet a foetus was
in no one instance disovered:  in other words, the contents
of the Graafian vesicles  were in no one  instance impreg-
  * The divided end of the tube was found totally impervious.—The
expei'iment succeeded when one tube only was divided: the division of
both deprived the animal not only of fertility, but of sexual desire, and
even the division of one had this effect in some instances.—If the tube
was divided after coition, the result was the same, provided the opera-
tion was performed before the contents of the vesicles had entered it:
for if too much time had elapsed, the ova were transmitted to the uterus,
and grew to maturity. 
             OF CONCEPTION AND  PREGNANCY.         329

nated.   Hence I infer, with Mr. Saumarez,  that  the con-
veyance  of  semen  along the  tubes  is  requisite  to im-
pregnation.   But  Dr.  Haighton likewise  concludes, that
the bursting of the vesicle  is  the sympathetic effect of the
semen  in the  vagina or uterus.*   Now although  on the
side where  the  tube was  divided  the ovarium did dis-
charge the contents  of  some vesicles, it is not proved that
it did this through the operation of the semen  in the var
gina or uterus.   The venereal ardour alone was shewn  in
the observations  of Mr. Saumarez, as well  as  in those  of
Mr. Cruikshank, to produce, among  other great changes
in the  sexual  organs,  the enlargement of  the vesicles,!
   * " That the semen first stimulates the vagina, os uteri, cavity of the
 uterus, or all of them.
   By sympathy, the ovarian vesicles enlarge, project, and burst.
   By sympathy, the tubes incline to the ovaria, and, having embraced
 them, convey the rudiments of the foetus into the uterus.
   By sympathy, the uterus makes the necessary preparations for perfect.
 ing the formation and growth of the foetus, and,
   By sympathy, the breasts furnish milk for its support after birth."
   There  is reason, however, from one passage, to suppose that Dr.
 Haighton believes the semen to exert all its direct effects upon the va«
 gina. After dwelling upon the opinion opposite to his own, he cays,
 '* The difficulties which were opposed to the conveyance of the  semen
 by the tubes  were, as we should expect, intended to prepare the way
 for a different explanation j therefore, physiologists,  by a very natural
 transition of thought, were led to suppose that the presence of semen
 in the vagina alone was sufficient to account for impregnation ;"  and ho
 immediately proceeds to his experiments.
  f The state of the ovaria of women, who have  died  under  strong
 sexual passion, has been found similar to that of rabbits during heat,
In the body of a young woman, eighteen years of age, who had been
brought up in  a convent, and had every appearance of being a virgin,
Valisneri  found fire or six vesicles protruding in one ovarium, and tho
corresponding Fallopian tube redder and longer than usual, as he ha 3
                             Uu 
330        OF CONCEPTION AND  PREGNANCY.
and it is highly probable that in  copulation, where it is car-
ried to its highest point, it is  capable  of laying the foun-
dation for their rupture.   There is more reason to believe
the rupture of the vesicles to be the effect  of this than of
the specific action of the semen.   Hen birds often lay eggs,
incapable  indeed  of being  hatched,  although  separated
from  the  influence of the cock,  proving that the  oestrum
alone is sufficient in  them to apply  the tube to the ova-
rium and convey away an ovum.  Aristotle and Harvey
relate that many birds  lay  eggs  from  mere   titillation;
the latter proved  it experimentally in  the  thrush and  the
sparrow, and  in a favourite  parrot belonging  to his wife.
Blumenbach is decidedly  of opinion that  the  contents of
a  vesicle  may escape the ovarium, and a corpus luteum
be formed in virgins, not simply from the analogy of birds,
but also from the accounts  which we have of such  exam-
ples, corresponding in climate, age, and temperament, with
what should be naturally expected :  it is related of young
women, inhabitants of warm countries, and subject to hys-
terical affections.*
   How the semen operates upon the ovarian secretion is un-
known.  Whether it is directly mixed with it,  or whether
its influence is transmitted to  the  ovarium by sympathy, its
specific operation, both of fecundating and of transmitting
the paternal peculiarities, is a mystery impenetrably conceal-
ed from human curiosity.
frequently observed in animals during heat.  Bonnet gives the history
of a young lady, who died furiously in love with a man of low rank,
and whose ovaria w  e turgid with vesicles of great size.  Blancaard,
Schurig, Biendelius, Santorini,  and  Drelinaourt,  mention analogous
facts.  Haller's notes to Boerhaave's Prxlect. Acad.
  * See his note to paragraph 562. 
OF CONCEPTION AND PREGNANCY.
331
  4. The rupture of the ovarium does not occur till some
time subsequent to coition.  Mr. Cruikshank did not see
ova in the Fallopian tubes of rabbits,  or orifices in the cor-
pora lutea, till the third day from copulation,* nor ova in the
uterus till the fourth.   Dr. Haighton never found any
thing of a  regular  form in the uterus  before  the  sixth
day.
  (B)  An  instance of superfetation, of the description
granted by  Blumenbach, occurred  to  Mr. Blackaller  of
Weybridge.   A white woman, of very  gay character, left
her husband,  and  some time afterwards returned pregnant
to her  parish, and was delivered in the work-house of
twins, " one of which,"  says Mr. Blackaller, in an account
which he very handsomely sent me,  " was  born  of a
darker colour than I have usually observed the infants of
negroes in the West Indies ; the  hair quite black, with the
woolly appearance usual to them, with nose flat, and lips
thick ;" the second child had all the common appearances
of white children.
  The uterus has  been  sometimes  wanting,! sometimes
destitute of  anterior opening,!  and sometimes double,^
in which case we may imagine superfetation possible at any
period after the first conception, provided each uterus has a
distinct orifice.
  (C) During 57 years, about  78,000  women have been
delivered at the Dublin Lying-in-Hospital,  and the pro-
portion  of women  producing twins, or more, is about 1
in57i
 • De Graaf and Valisneri met with the same results.
 t Lieutaud, Sandifort, Morgagni.
 ! Louis.
 § Ephemerid. Natur. Curios. Dec. 3. Ann. 7 and 8. Obs. 35. Cent.
). Obs. 75. Philos. Trans, vol. 4. 1699. 
342         OF CONCEPTION AND PREGNANCY.

  The proportion of males to females, about 10 to 9.*
  (D) Fourcroy is almost the only author who has examin-
ed the blood of the foetus,!  and his observations, as Berze-
lius  remarks, " seem  to have  been made by chance, and
not to be deduced from any experiment;" "credible authors
have  asserted, that the eye  cannot distinguish  between
the arterial  and  venous blood of the  foetus."!    Bichat
could  observe  no difference  in  the  arterial and  venous
blood of the umbilical chords of several guinea pigs,  exam-
ined while the mother's respiration was still continuing after
an opening had  been made into the abdomen ; " les deux
sangs offroient une noriceur egale."!   So too in regard  to
dogs. ||
  The chick, however, in the egg, cut off  from all inter-
course with the mother, requires its blood to be purified
by the external air :  for if the shell is varnished, the chick
dies : and if, during the latter half of incubation,  the shell
is carefully  opened, the chorion,  to  use the eloquent lan-
guage of Blumenbach^ presents  the  most  beautiful spec-
tacle in the organic creation ; the arteries are  seen carry-
ing blood of a bright scarlet, and  the veins of a livid red.
* Sh-tches of the Medical Schools of Paris, by John Cross, p. 192.
\ Annates de Chimie. T. vii. p. 162.
j Animal Chemistry. Translation, p. 41, sq.
§ Becherckes Phisiologiques, p • 271.
y Analomie Generale, T. ii. 344.
*, Comparative Anatoviy. Translated by Mr. Lawrence. 
OF THE NISUS FORMATIVUS.
333
SECT. XL.
               OF THE NISUS FORMATIVU5.


   583. Having simply  described  the  phenomena  of
conception, and the changes which  constant observation
shows to  occur both to the ovum and the  contained  foetus
during pregnancy,  we  now  proceed to  those powers,  by
which it appears that generation is effected.
   584. Even in our memory, some  physiologists of repu-
tation have  contented themselves with  roundly asserting
that true generation  never  occurs,  but  that the whole
human race pre-existed in  the genitals of our first parents,
in the shape of previously-formed germs, which become
evolved in succession.   Some of these imagined the germs
to be  the spermatic  animalcules  of the  male ;*  others
imagined them to exist in the ovaries of the mother.-j-
  • See W. Fr. v. Gleichen, 1. c.
  f v. c. The illustrious Haller, who plainly asserted, that all the
viscera, and  even the bones of the future ftetus,  nearly fiuid indeed,  and
therefore  invisible,  viere preformed,  before conception, in the maternal
germ.
  In support of this hypothesis, he argued chiefly from the continuity
of the membranes and blood-vessels between the incubated chick and
the yolk of the egg.   Opera minora. T. ii. p. 418, sq.
  But the more frequently I  have demonstrated the phenomena of in-
cubation, in  my Physiological Lectures, the less strength have I found
in this argument-  Nor can I sufficiently wonder how this great physi-
ologist could so constantly reject,  as almost  absurd, the inosculation. 
334
OF THE NISUS FORMATIVUS.
   585. This hypothesis  of  the  successive  evolution of
germs,pre-formed from the creation, must, if carefully exa-
mined, be rejected.*   Not only  is the superfluous and Use-
less  creation which is supposed,  of  innumerable  germs
never  arriving at evolution, repugnant to reason, but so
many  preternatural conditions!  and  such  a multiplica-
tion of natural powers! are  assumed,  that it  is perfectly
irreconcileable with sound physiology.
   Add to this, that,  of the phenomena  adduced  in  its
favour, no one  is sufficiently  consonant with  the truth of
nature to prove the hypothesis.^
   On  the other  hand, we have indubitable  observations
which refute it directly and completely.
   586. The less this  hypothesis  of  evolution,  as  it is
commonly termed, is  found  consonant  with fact and  the
rules of philosophizing, the  more strongly does  the oppo-
site opinion recommend itself to  our notice by  its simplicity
and correspondence with nature, supposing, as it does, not
an evolution of fictitious germina by conception, but a true
properly so called, of the vessels of the chick with those of the yolk,
while, at the same time, he admitted and defended a perfectly similar
inosculation in the connection of the human  ovulum with the gravid
uterus.  Elan. Physiol.  Lausanne, 1788, T. viii. P. 1. p. 94, comparing
p. 257.
  • v. L. P. Zweifel gegen die Entviickelungstheorie.—Aus der Franzbsischen
Handschrift von G. Forster. Gbtting. 1788, 8vo.
  f v. Kant's remarks  on these, in his Critik der  Urtheilskrqft, page
372.
  \ This defect  I have shown at  large in my Handbuch der Natur-
geschichte, page 15, sq 8vo. 1807.
  § Those who desire a fujjer demonstration of this and other assertions,
but briefly noticed in the present section, I refer to the work, uber den
Bildungstrkb, (third edit.) Gotting. 1791, 8vo. 
               OF THE NISUS FORMATIVUS.           335

and gradual formation  of a  new  conception  from  the
hitherto formless genital matter.
  587.  This true generation by  successive  formation has
been variously described by physiologists, but the follow-
ing we consider as the true account:
  1. The matter  of which organized  bodies,  and there-
fore the human frame,  is composed, differs from all other
matter  in this, that it  alone is subject  to the influence of
the vital powers.*
  2. Among the orders of vital powers, one is eminently
remarkable, and the  least disputable of  all,—which,  while
it acts upon that matter  hitherto shapeless, but mature, im-
parts to it  a form regular and definite, although varying
according to the particular  nature of  the  matter.  To
distinguish  this vital power from the  rest,  permit  us to
designate it by the term,—-nisus formativus.
  3. The  nisus formativus  occurs to  the genital matter,
when this is mature, and committed  to the uterus in a
proper condition and under proper circumstances, lays in
it  the  rudiments   of conception,  and  gradually forms
organs fitted for particular  purposes ; preserves  this struc-
ture during life, by nourishing (455, sq.) the body; and
reproduces  (459),  as far as  it can, any part accidentally
mutilated.!
  • See  Chr.  Girtanner, uber das Kantische Prinzip fur die Natur-
geschichte. Gotting. 1796, 8vo. p. 14, sq.
  f Here allow me to make three remarks :—
  1. I have used the expression, nisus formativus, merely to distinguish
it from the other orders of vital powers, and by no means to explain the
cause of  generation,  which I consider equally involved in Cimmerian
darkness as  the cause of gravitation or attraction, which are merely
terms given to effects known, like the nisus formativus, a posteriori. 
336
OF THE NISUS FORMATIVUS.
   588. We therefore think it very probable that those fluids,
 which, during a  successful coition,  are thrown into  the
 cavity of the uterus (527,  533, 45l), (A) require  a  cer-
 tain period for becoming intimately  mixed,  acted upon,
 and matured;  that, after this  preparatory  stage, the nisus
 formativus is excited  in  them,  vivifying and  shaping the
 hitherto shapeless  spermatic matter, partly into the  beau-
 tiful containing ovulum, (565) and partly into  the con-
 tainedjejnbryo; (569) and  that this is  the reason  of our
 inability, notwithstanding the present perfection of optical
 instruments, to  discover, during  the first weeks  after con-
 ception, any  thing more than shapeless  fluids, without
the faintest trace of the  form of an embryo, which, how-
ever, about the third month, as it  were, suddenly becomes
 observable.
   589. We should exceed the limits of these  institutions,
were we  to adduce many of the  arguments which may be
 drawn  from  facts, to illustrate,  as, in our  opinion, they
most clearly  do, the  great  influence  of the nisus forma-
tivus in generation. We will, however, venture to mention,
    2. The word nisus I have adopted chiefly to express an energy truly
  vital, and therefore to distinguish it, as clearly as possible, from powers
  merely mechanical, by which some physiologists formerly endeavoured
  to explain generation.
    3. The point on which the whole of this doctrine respecting the nisus
  formativus turns, and which is alone sufficient to distinguish it from the
  vis plastica of the ancients, or the vis essentialis of the celebrated Wolff,
  and similar hypotheses, is the union and intimate co-exertion cftvso distinct
  principles in the evolution of the nature of organized bodies,—of the physico-
-  mechanical, viith the purely telf.ological—principles which have
  hitherto  been adopted, but separately, by physiologists, in framing the-
  ories of generation. 
                OF THE NISUS FORMATIVUS.           337

 as briefly as possible,  a few,  whose  weight  will, on a
 litt'e close reflection, be sufficiently evident.
    590.  Such, in the  history of  hybrid animals,  is the
 singular experiment of  impregnating  those  whi  h are
 prolific, for many generations,  with male  semen   f the
 same species, by means of which  the  form of the   oung
 hybrids become  so  progressively  different  from tl.   ori-
 ginal  maternal  configuration, as  to approach  mo    and
 more to that of the  father, till,  by a  kind of ar   rary
 metamorphosis, it is absolutely converted into it.*
   591. Such, in  our knowledge of monsters, (which, ac-
 cording to  the  hypothesis of  evolution,  are  nearly all
 maintained  to have  pre-existed in the germs from the
 first  creation,)  is  the  well  known fact, that  among cer-
 tain domestic species  of animals,  and  especially among
 sows, monstrosities are very common, while in the ori-
 ginal wild variety they are extremely uncommon.
   592. While the phenomena of reproduction are all  much
 more explicable by the nisus formativus than by the pre-
 existence of germs for ever)7 part,  some  particular in-
 stances, (v. c. that of the nails, which,  after the loss of
 the  first phalanx of  the  fingers, have been known  to be
 reproduced on the neighbouring  middle  phalanx,!) admit
 evidently of no other solution.
   593. From an  impartial view  of each side of the  ques-
 tion,  it will  clearly appear, that  the  defenders  of  the
 germs must allow  to the male semen, not only an exciting
 power, as  they do, but likewise great formative powers,
and thus their doctrine stands in  need of the assistance of
the nisus formativus; while  our  explanation, on the con-
• Jos. G. Kblreuter. Dritte Fortsetz. der vorlSuf. Nachr. p. 51, sq.
f Tulpius. Observat. Med. L. iv. c. 55.
                        Xx 
338
OF THE NISUS FORMATIVUS.
trary, is sufficient, without the  aid  of pre-existing germs,
to explain the phenomena of  generation.   Nor  can  there
be any reason for multiplying the entia, as  they are called,
unnecessarily (B).
NOTES.
   (A) See note A. to section 39, near the end.
   (B) The nisus formativus produces  a  being generally
resembling the  parents, but  occasionally different.  This
subject will be fully treated of in the note on the varieties
of mankind.
   It  is not probable that the ardour of the  procreants
affects the energy of the offspring.  But from the  days of
Aristotle it has been remarked ,that bastards are very  fre-
quently endowed  with  great genius and valour, and both
ancient and  modern history certainly  afford  many such
examples,  and  the  circumstance   has been  commonly
ascribed to the  impetuosity of the parents during  their
embraces.   Shakspeare,  in  King  Lear,  introduces  Ed-
mund bursting into this indignant soliloquy :
             " Why bastard ? wherefore base ?
       When my dimensions are as well  compact,
       My mind as generous, and my shape as true,
       As honest madam's issue ?  Why brand they us
       With base ? with baseness ? bastardy ? base ? base 1
       Who, in the lusty stealth of nature, take
       More composition and fierce quality,
       Than doth, within a dull, stale, tired bed,
       Go to the creating a whole tribe of fops,
        Got 'tween sleep and wake ?"
                                      Act, 1. Sect. 2. 
              OF THE NISUS FORMATIVUS.           339

   Were this explanation satisfactory, the  first fruits of
wedded love would still be on an equality with illegitimate
offspring.  If a greater proportion of illegitimate than of
legitimate  persons  have really  rendered themselves illus-
trious, I  should attribute  their  superior energy  to the
strength of their parents  constitutions, as the weak and
delicate  cannot be supposed  so frequently  to  yield  to
unlawful passions as the vigorous, and  to the necessity in
which such individuals usually find  themselves  to rely
upon their own exertions. 
340         OF  LABOUR AND ITS SEQJJ£L£.
SECT. XLI.
             OF LABOUR AND ITS SEOJIELjE.


  594.  The foetus,  formed by  the powers  already  de-
scribed, and having reached the period of full maturity,
has to come into the world by means of labour.*
  595.  This critical period occurs  naturally  (and physi-
ology treats solely of natural occurrences) at  the end of
the tenth lunar month  from  conception,  i. e. about  the
39th or 40th week.
  596.  At that time, the pregnant woman is  impelled to
bring forth  by an absolute  necessity,  less under the in-
fluence  of the will than  any  other  voluntary function
(287).
  597.  Physiologists have differed  in  their  explanations
of the  causes of  so  determinate and  sudden an event.
After all, the exciting cause of labour must be ascribed to
an eternal law of  nature, hitherto equally  inexplicable as
so many other periodical phenomena in nature ; v.  c. the
metamorphosis  of insects,  the  stages of exanthematic
fevers,  crises, &c. &c. nor has the mature ovum been in-
aptly compared, ceteris paribus, to fruit, which, when ripe,
falls almost  spontaneously to the ground, from the con-
striction of  those vessels which  previously conveyed its
* J. J. Rbmer. Partus naturalis brevis expositio.  Gotting. 1786,8vo- 
OF LABOUR AND ITS SEQJJEL.*.         341
nourishment.    And in fact it has been remarked, that
the human  placenta, at  the approach of labour, is con-
tracted, and, as it were, prepared for its separation from
the uterus.
  What is usually urged respecting the utmost expansion
of the uterus, and other similar excitements to labour, is
refuted by many circumstances, and,  among the rest, by
the numerous examples of extra-uterine, whether tubal or
ovarian, conceptions, in which,  at the  expiration of  ten
months from impregnation, the uterus, notwithstanding its
vacuity, is seized with the customary, though indeed fruit-
less, pains.*
   598.  Besides this exciting cause, other very powerful
efficient causes are requisite, as must be manifest from  the
relation of the ovum to the uterus.
   We are persuaded that the proximate and primary  cause
is solely the vita propria of the uterus (42, 547).
   Among the  remote, the  most important  appears  to be
the respiratory  effort, excited principally  by the great con-
nection! of the intercostal nerve with the rest of the nervous
system.
   599.  We formerly noticed (582) that, during  the  latter
periods of pregnancy, the uterus somewhat subsided, by
which circumstance the form of the abdomen  is somewhat
changed, and the inconveniences induced  during advanced
pregnancy, in the function of respiration, are relieved.  At
the same time,  the vaginal mucus (543) is secreted  more
abundantly, the vagina itself is relaxed, the  columns of
ruga? are almost obliterated, the labia pudendi swell; finally,
  • I have recorded a remarkable instance of this kind in the Comment-
Soc. Scient.  Gottingens. Vol. viii.
  f v. Camper's Demonst. anat. pathol. L. 11. p. 9. 
 842         OF LABOUR  AND  ITS SEQUEL/E.

 near the approach of labour, the os uteri  gradually dilates
 into a circular opening.
   600.  The phenomena  of labour  generally  observe  a
 regular order of invasion and cessation,* whence accou-
 cheurs  have divided  them into  stages, Of which  the
 moderns enumerate four, although they define them va-
 riously.
   601.  In the first, the true pains occur, peculiar in their
 nature,  proceeding  from  the  loins  downwards, in  the
 direction  of the uterus  (recurring at intervals, indeed,
 during  the whole  of labour, with various degrees of vio-
 lence and frequency), at first mild, when they  are  called
 warning, and the os uteri  begins  evidently to dilate.  At
 the same time the abdomen falls still more, the urine  is ur-
 gent, and abundance of mucus flows from the soft and  tumid
 genitals.
   602.  In the second, the pains, increasing, are  called pre-
paring, and, from the  compressing effect of the respiratory
 organs  by means of a strong inspiration, a segment of the
 lower part  of the  membranes  of  the ovum  is  protruded
 through the uterine orifice into the vagina.
   603.  In  the third, the  pains,  becoming more  excruci-
 ating, are  called labour pains, and  act  with  still more
 violence upon  the uterus, which is  driven downwards,
 and compressed against the foetus, so  that  the protruded
 segment of membranes  becomes extremely tense, is burst
 asunder, and  the  greater  part of the liquor  amnii es-
 capes.
   604.  Finally, in the fourth and last stage, the pains, be-
 coming dreadfully violent and agitating,] are accompanied
* v. Smellie's Set of anatomical tables. tab. xi.—xv.
t Although, even among my own countrywomen, the symptoms, 
OF  LABOUR AND  tTS SEOJJELjE.          34J
with great exertions of the woman herself; almost always,
too,  with  shivering,  shrieking, tremor of the  knees, &c.
The head of the child,  now on  the  verge of birth, pene-
trates, and  the  face first appears,  the  vertex usually ad-
hering under the arch of the pubis, and the rest of the head
in the mean time  being farther propelled, and revolving
around the impacted vertex as around an  axis.   Thus the
child comes into the world in the midst of a red discharge,
consisting of a  second  portion  of the liquor amnii  mixed
with blood.
   605.  Soon after the expulsion of  the child, the after-la-
bour commences, attended  with a painful though much less
violent exertion, and followed by another hemorrhage, from
that part of the  cavity of the  womb*  to which the placenta
had adhered by  means of the decidua crassa.!
described under these four stages, vary greatly in violence and propor-
tionate duration; nevertheless, however naturally they take place, they
universally, (excepting some extremely rare cases,) so far surpass, even
under the most favourable circumstances, the pains experienced by do-
mestic brutes in their labours, that, I trust, no one, who has frequently
witnessed labours in both, will seriously doubt the immense difference
between the two in this respect.
  * B. S. Albinus' Tab. uter. gravid, vij.
  Wm. Hunter's Anat. of the gravid uterus. Tab. x. fig. 3.
  t Nic. Massam,  and all since  his time, denominate this portion of
the womb, during, or shortly after, pregnancy, the cotyledons,  from the
analogous appearance observable in the gravid uterus of sheep or goats,
in which similar cavities facetabulaj exist, receiving what are called
the glandular corpuscles of the chorion, corresponding with the foetal
portion of the human placenta.
  Whatever was hollow, like an  acetabulum, was called kotv^h, by
the ancients.   Vide  J.  Cammerarii,  Comm.  utriitsque  lingua,  256,
.184. 
344
OF LABOUR A*ND ITS SEOJJELjE.
  605. Immediately that both burthens are expelled, the
uterus begins gradually to contract, until  it acquires  its
original form, and very nearly its original dimensions.
  607. For about a week after labour, the lochia are dis-
charged, for the  most part very  similar to the catamenia,
but rather more copious, especially if the mother does not
suckle her offspring.   About the  sixth day, their red co-
lour becomes fainter,  and  afterwards  is  converted into
white.  At  the same time the uterus is liberated  from the
ramenta  of  the decidua,  and having thus  completed the
function of pregnancy,  is  again ready for menstruation  or
conception. 
OF THE MILK.
34.'
                    SECT. XLII.


                     OF THE MILK.


   608. The breasts, most  sacred  fountains,  and, as Gel-
lius Favorinus,  the  philosopher, elegantly calls them, the
educators of the human race, are intimately connected with
the uterus in various ways.  The functions  of neither can
properly be said to exist during infancy :  at puberty, both
begin to flourish,—when the catamenia appear, the breasts
assume some degree of plumpness :  from that period they
undergo either  simultaneous changes,—the  breasts begin-
ning to swell and secrete milk during the pregnancy of the
womb ;  or alternate changes,—the catamenia ceasing while
the child is suckled,  or the  lochia  becoming copious  if
the child is not suckled, and s.  p.   Finally, when  age
creeps on, the function of each absolutely  ceases,—when
the catamenia disappear, both the uterus and the breasts
become  equally inert.   I omit pathological phenomena ;
v. c. those which occur in irregular menstruation, leucorr-
hoea, after extirpation of the ovaria,  and in other morbid af-
fections.
   609.  If this intimate connection is kept in  view, we shall
not be astonished that nearly every description  of sympathy
formerly mentioned (56) exists between these organs of the
female thorax and abdomen.*
  • J  Anemaet De mirabili qute mammas inter et uterum intercedit tym-
pathia. L. B. 1784, 4to.
                         Yy 
346                  OF THE MILK.
  610.  The  influence of  the anastomatic sympathy be-
tween  the  internal mammary and  epigastric artery,*  al-
though  formerly  overrated,!  is  evinced  by the  change
which the latter experiences in its diameter during pregnan-
cy and lactation.
  611.  Both the uterus and mammae appear to have a kind
of affinity for the chyle, observable in many  diseases, and
nearly always in new-born children.
  612.  The breast of women,! belonging to the  most cha-
racteristic marks of the human female, both by its form du-
ring the flower of age, and by the longer continuance of this
form after the period of suckling, than occurs in any other
female animal, is composed of a placentiform series of con-
glomerate glands, divided by numerous furrows  into larger
lobes, and buried in a mass of fat;  the anterior  part swells
out particularly with a firmer description of fat, over  which
the skin is exceedingly thin.
  613.  Each  of these lobes  is  composed of still smaller
lobes, and these of acini, as they are termed, to  which the
extreme radicles§ of the lactiferous ducts adhere,  deriving
a chylous fluid from the ultimate twigs of the internal mam-
mary arteries.
.  614.  These radicles, gradually  uniting,|| form  large
  * Eustachius. Tab. xxvii. fig. 12^'
  Haller. Icon. Anat. fasc. vi. tab. i.
  ! As G. R. Boehmer properly remarks. De consensu uteri eum mam,-
mis causa lactis dubia. Lips. 1750, 4to.
  \ A. B. Kblpin, De structura mammarum. (Triphisw. 1765. 4to.
  Athan.  Joannidis, Physiologia: mammarum muliebrium specimen.
Hal.  1801. 4to.
  §v. C.  Avolo's two plates at the end of Santorini's  posthumous
works.
  || v. Mich. Girard, Tab. i.  annexed to the same plates of San.
torini. 
                      OF THE MILK.                  347
trunks, corresponding  in  number with  the lobes,  about
fifteen in each breast.   These  are every where dilated  into
large  sinuses,  but  have  no  true  anastomosis  with each
other.*
  615. These trunks terminate in  very delicate excretory
canals, which are collected  towards the centre,  by means
of cellular  substance,  into the  nipple,-]  which, supplied
with  extremely  fine blood-vessels  and nerves,  is capable
of a curious erection on  the approach of certain  external
stimuli.
  616. The nipple is surrounded  by the areola,] which,
as well as  the  nipple,  is  remarkable for the colour§ of
the reticulum under  the cuticle,||  and contains  sebaceous
follicles.^]
  617. The secretion of the breast is the milk, well known
in colour, watery, somewhat fatty,  rather sweet, bland, re-
sembling  in all  respects the milk of domestic animals, but
subject to infinitely greater varieties in the proportion of its
constituent  parts, and far more difficult of  coagulation, from
the great quantity of salt which it  contains, and affording no
trace of volatile alkali.**
  * J. Gottl. Walter's Observ. Anat. p. 33. sq.
  f Santorini's Tab. posth. viii.
  \ Ruysch. Thes. i. tab. 4. fig. 4.
  § In pregnant women, especially during the first pregnane}', the nip-
ples are usually yellow.  In the Samojede women, although virgins,
Klingstaedt asserts that they are quite black. M£m. sur les Samojedes
et les Lappons. p. 44.
  || B. S. Albinus' Annotat. Acad. L. iii. tab. iv. fig. 3.
  If Morgagni's Advers. Anat. 1. tab. iv. fig. 2.
  •• Fl. J. Voltelen (Prxs.  Hahn), De lacte humano observations che-
mi ex.  L. B. 1775. 4to.
  Parmentier and Deyeux, Precis d*Experiences et Observations sur  l/s 
348
OF  THE MILK.
   618. When coagulated by means of alcohol, it  discovers
the same elements as the  milk of other animals.   Besides
the aqueous  halitus  which  it  gives off when fresh and
warm, the serum, separating from the caseous part, contains
sugar of milk,* acetic  acid mixed with phosphate of lime
and of magnesia, and with  oil  and mucus.   The buty*
raceous cream is said to consist of globules  of various and
inconstant size, their  diameter  ranging  between ¥^7 and
F^ of a line.f (A)
   619. The analogy between chyle and blood, and between
both  these  fluids and milk,! renders  it probable that the
milk is a kind of reduced chyle, again  separated  from the
blood before  its complete  assimilation.    This idea is
strengthened by the frequent existence in the milk of the par-
ticular qualities of food previously taken,§ and by the chy-
lous appearance of the  watery milk afforded by the breasts
during pregnancy, and immediately after labour.)!
diffe'rentes especes du lait. Argent. 1798. 8vo.   Thenard, in the Annates dr
Chimie. T. lix. p. 262.
  • Marc. L. WiUiamoz, De sale lactis essentiali. L. B. 1756. 4to.
  f Senac. Tr. du coeur.  Vol. ii. p. 276. ed. 2.
  Fr. v. P. Griuthuisen.   Untersuch.  uber den Unterschied zmisehen
Eiter und Schleim durch das  Microscop.  Monach. 1809.  4to. p. 16.
fig. 15.
  ! Compare J. Theod. Van de Kasteele.  Dim. de analogia inter  lac
tt sanguinem. L. B. 1780. 4to. and Alex. Wilson, on the analogy be-
tween milk and chyle, in his Observations relative to the influence of the
climate, p. 97.  sq.
  § v. among a host of witnesses, Kblpin, in Pallas', Neuen nordischen
Beytr'dgen. Vol. ii. p. 343.
  || Many arguments induce me to  believe, that the .lymph  of the
absorbents is of much importance in the secretion of milk.
  For instance( the swelling of the subaxillary glands, almost always
observable during the first months of pregnancy. 
OF  THE  MILK.
349
  620.  The  reason why  this bland nourishment  of the
foetus becomes,  by  continued  sucking,  more  thick and
rich,  is probably  the  abundance of  lymphatics  in  the
breasts.   Those  vessels  continually  absorb more  of the
serous part of the milk, in proportion as  its secretion is
more copious and lasting, and, by again pouring this por-
tion into the mass of blood, promote the  secretion (477) :
after ablactation they take up the residual milk, and  mix it
with the blood.
  621.  The milk  is secreted in greatest quantity immedi-
ately  after delivery; and,  if the  infant sucks, amounts to
one or two  pounds every twenty-four hours, until the men-
ses, which usually cease during suckling, (556) return.
  Occasionally virgins, and new-born infants  of either sex,
nay even men,* as well as the adult males of other mamma-
lia,! have been known to furnish milk.
  622. The abundance of milk excites  its excretion, and
even causes it to flow  spontaneously : but pressure,  or the
suction of the child, completes its discharge.
  But especially the remarkable fact, that in advanced pregnancy, when,
from the womb compressing, through its size, the large and numerous
lumbar plexuses of lymphatics, the legs have swollen, this ocdematous
tumour so completely disappears, immediately after labour, that the
calves of the legs hang almost flaccid, from the lymph finding no impe-
diment in the lumbar plexuses, and rushing upwards; and a more copious
secretion of milk instantly ensues upon the progress of the lymph.
  The momentary thirst (330) experienced en applying the child to the
breast,  from the absorption of fluid in the fauces, may be also men-
tioned.
  • This is asserted to be very common in Russia. Comment. Acad. *.■.
Petropolit. Vol. iii. p. 278. sq.
  f I have spoken of this at large in the Hannoversich Magazin. 178?".
p. 753. sq. 
850
OF THE MILK.
                       NOTES.
   (A) The lower portion of cows' milk that had stood some
 days was found by Berzelius* to have a specific gravity of
 1.033, and to contain
     Water.......928.75
     Cheese, with a trace of butter  -    -     -     28.00
     Sugar of milk.....35.00
     Muriate of potash.....1.70
     Phosphate of potash      -                     0.25
     Lactic acid, acetate of potash, with a trace of
         lactate of iron -----      6.00
     Earthy phosphates       -                     0.30

                                                1000.00

   The supernatant cream contained
     Butter.......4. 5
     Cheese       ------      3. 5
     Whey.......92. 0
   (B)  It may be worth while here to take a general  view
of the subject of generation.
   Life  never  occurs  spontaneously in  matter,  but is
always  propagated   from  an  organized  system already
endowed  with it.    Such,  at least, appears to  be the
inevitable  conclusion from  the  facts within  our  obser-
vation.    No  instance  has  been  known of a plant or
animal  of any  species, whose  mode  of propagation is
ascertained, ever springing  up  spontaneously;  and  al-
though  in  many  cases   the  origin cannot  be  disco-
vered,  yet surely our inability  to  discover the mode of
* Medico-CJiirurgical Transactions. V. iii. 
OF THE MILK.
351
propagation does not justify  us in  denying  the existence
of it;  but  the  general  analogy,  the  discovery  of  the
modes in which many  species  propagate, which were  for-
merly adduced  as  instances  of  spontaneous generation,
and  the occasionally   manifest source  of the  difficulties
which obstruct our enquiries, lead necessarily  to  the belief,
not  of  the absence of the faet, but of our deficient  pene-
tration.*
  The  simplest  mode of  increase  is by the detachment
and  independent existence of  a portion of a  system.   In
this  way trees,!  polypes, some worms,  and many animal-
cules,!  multiply.
   Next comes the  formation  of  the  rudiments of a per-
fectly new  being by  the system  of  another.   Thus  we
have the  seed of vegetables,  the ova  and foetus of  ani-
mals.   This occurs by means of  two  matters, which in
some examples are furnished by  the same, and in others
  * See Cuvier's Anatomie Compare'e.—Generation.
      f  Hie plantas tenero abscindens de corpore matrum
        Deposuit sulcis ;  hie stirpes obruit arvo,
        Quadrifidasque sudes, et acuto roborc vallos :
        Sylvarumque alise pressos propaginis arcus
        Expectant, et viva sua plantaria terrd.
        Nil radicis egent alise : sumraumque putator
        Haud dubitat terra referens mandare cacumen.
        Quin et caudicibus scctis, mirabile dictu,
        Truditur € sicco radix oleagina ligno.
                                  Virgil.  Georgica. Lib. ii.
  | See  Spallanzani's admirable Observations et Experiences sur les Ani-
malcules.  He found a small portion detach itself from the bodies of
some, the bodies of others split longitudinally, of others transversely, of
others both longitudinally and transversely,  into four  parts ; and  the
new animalcules soon acquired the size of the parent, and experienced
the same changes in their turn. 
352
OF THE MILK.
by different  systems.  The  vegetable  kingdom  affords
innumerable instances of  the former,  the acephalous mol-
lusca and the echinus are examples  in  the  animal king-
dom.*   Both the vegetable and animal  kingdoms  abound
in instances of the latter.  Here again  there are three va-
rieties.   The fluid  of the male may be  applied to the  ova
of the female after they are discharged from her body, ae
in fish  of the  bony  kind and cephalopodous  mollusca ;
while being discharged,  as in the  frog and toad ;  or it
may  be conveyed to  the  female system, and this either
without the  contact  of the male, as in  vegetables, where
the wind, insects,  Sec. convey it,  or by means of copu-
lation,  as  in  the mammalia,!  birds,  most  reptiles,  and
some fish.
   In the mammalia, one  copulation is sufficient for only
  • It is singular, that some hermaphrodites do not impregnate them-
 selves, but mutually impregnate, and are impregnated by, others ; such
 are the gasteropodous mollusca, and many worms.
  f Ladies were treated formerly more politely than at present.   An
 accidental pregnancy was often attributed to the warmth of imagina-
 tion, the influence of demons, and many other circumstances, supposed
 equally powerful as the deed of kind.  Venette, in his Tableau de
 VAmour conjugal, has inserted an Arret Notable de la cour du Parlement
 de Grenoble, which, upon the attestation of many matrones and sages,
femmes, and docteurs of the University of Montpellier, that women often
 fall pregnant spontaneously, declares a lady, who had brought forth a
 son, although her husband had been absent four years, to be a woman
 of worth and honour, and the child to be the legitimate heir of Monsieur
 the husband.
  Virgil believed that mares were sometimes impregnated by the west
 wind.
        Vere magis (quia vere calor redit ossibus) illx
        Ore omnes versse in Zephyrum, stant rupibus altis 
OF THE MILK.
353
one conception ;  among poultry its effects are  so  exten-
sive,  that a  hen turkey  will lay the whole season after
one intercourse with  the  cock ; in the aphis, and  some
monoculi, it is sufficient for  the impregnation of several
generations.
  The ovum after its formation may be  nourished by  a
fluid  enclosed within the same  case, and  is then hatched
out of the body by the common  temperature, as in insects,
or by that of the parent, as in birds, or hatched within the
body  of  the mother,  as  in serpents; or  it may be nou-
rished by a substance shed around it in the womb, as in
the kangaroo, or by means of  an attachment of some of its
vessels to the maternal system,  as in the mammalia; some
animals being thus oviparous, others ovo-viviparous, and
others viviparous.
  The mode of nourishment  after birth is various.   Some '
are able, without any peculiar  arrangement, immediately to
support themselves,  for the wisdom of nature ordains  the
delivery of each species of animals at that season of the year,
when every thing is in the most  favourable state for admi-
nistering to the necessities of the offspring.
  Others, many insects for example, are born in the midst
of food,  the parent  having instinctively deposited the egg
in nutrient matter, either found or carefully collected by
her.
  Others have food collected daily by the parents.  Others,
as all the dove kind,  are  fed by a substance secreted from
Exceptantque leves animas : et sxpe sine ullis
Conjugiis, vento gravida: (mirabile dictu)
Saxa per et scopulos et depressas convalles
Diffugiunt
                                 Georg. Lib. iii
                   Z/ 
354
OF THE MILK.
the crops of both parents* ;  others by a fluid secreted by
peculiar glands belonging to  the female only.   The instinct
which leads the parent carefully to tend the offspring ceases
at the period, when the system of the offspring is sufficiently
advanced to supply its own exigencies.
  • Hunter, On a secretion in the crops of breeding pigeons for the nourish-
ment of their young.  Observ. p. 235. 
BEFORE AND AFTER BIRTH.
355
                     SECT.  XLIII.

   OF THE  DIFFERENCES IN  THE SYSTEM  BEFORB  AND
                      AFTER BIRTH*.

   623. From what has  been said relatively  to the func-
tions of the foetus  still  contained within  its  mother, and
immersed as it were in a warm bath,  there  must evidently
be a considerable difference  between its animal functions
and those of the child which is born, and capable of exerting
its will.  The chief points of difference we shall distinctly
enumerate.
   642. To begin with the blood and  its motion : this  fluid
is remarkable, both  for  being of a  darker red, incapable
of becoming  florid on the contact of atmospheric air, and
for coagulating less readily and  perfectly than after birth!-
Its course  too is very different in the foetus,  whose circu-
lation is connected with the placenta, and who has never
  * On the subject of this section consult, among numerous others,
Trew, De differ, qvibusdam inter homincm natum et nascendum interceden-
tibus. Norimb. 1736.4to.
  Andr. and Fr. Roesslein (brothers), De differentiis inter fa turn et
adultum- ibid. 1783, 4to.
  Ferd. G. Danz. Zerglicderungskunde des ungebohrnen Kindes mil Anmerk.
von. S. Th. Soemmering, Francof. 1792. 2 vols. 8vo.
  Also Theod  Hoogeveen,  De foetus humani mortis- L. B.  1784. 8vo.
p. 28. sq.
  J. Dan. Herholdt, De vita imprimisftttus humani.  Havn. 1802. 8vo. p.
61. sq.
  And Fr Aug. Walter, Annotat. Academ. already quoted, p. 44.  sq.
  t Fourcroy. Amales de Chimic T. vii. p. 162. sq 
 356       OF THE DIFFERENCES IN THE SYSTEM

 breathed,  from  its course  after the  cessation of this con-
 nection  with the  mother,  and after respiration has taken
 place*.
   625.  First, the umbilical vein coming from the placenta,
 and penetrating the ring  properly called umbilical, runs
 to  the liver,  and pours  its  blood  into  the sinus of  the
 Vena porta-,  the branches  of which remarkable  vein  dis-
 tribute one  portion  through  the liver, while  the ductus
venosus  Arantii! conveys tbe rest directly to the inferior
 vena cava.
   Both canals,—the end of the umbilical vein contained  in
the  abdomen  of the foetus, and  the venous duct, become
closed after the division of the  chord, and the former is
converted  into the round ligament of the liver.
   626. The blood arriving at the right side  of the  heart,
from the inferior cava, is in a great measure prevented from
passing  through the lungs,  and  is derived into the left  or
posterior auricle of the  heart, by means of  the Eustachian
valve and  the foramen ovale.
   627. For,  in the foetus,  over the opening  of the inferior
cav?, there is extended a lunated valve], termed, from its
  * Compare Herm. Bernard  De eo quo differt circuitus sanguinis fatus ab
>'do hominis nati. Reprinted in Overkamp's collection. T. i.
  Jos.  Wenc. Cziknnck,  De actuosa hominis  nascituri vita s. circulat-
fcetus ab hominis nati diversitate-  Reprinted in Wasserberg's collection.
T. iv.
  Sabatier,  at tlie end of his  Tr, Complet, d'Anat. Vol. iii. p. 386. sq.
1781. and in the Memoires Mathemat. et Physiques de I'Institut. T. iii.
p. 337.  sq.
  But especially J. Fr. Lobstein, in the Magasin Encyclope'dique. 1803.
T. iii. Vol. Ii. p. 28 sq.
  t Arantius,  De humanofatu libetlus. 97.
  Compare  B. S Albinus's Explicatio tabular. Eustachii. p. 164. sq.
  t Haller,  De va'vula Eustachii. Gotting. lr38 4io. 
BEFORE AND AFTER BIRTH.
357
discoverer*,  Eustachian, which usually disappears as ado-
lescence proceeds, but, in the foetus, appears to direct! the
stream of blood coming from the abdomen towards an open-
ing, immediately to be mentioned, existing in the septum of
the auricles.
   628.  This  opening  is denominated  the foramen  ovale],
and is certainly the chief cause why the blood which streams
from  the inferior cava is poured into the left auricle,  during
the diastole of the auricles.  A falciform^ valve, placed
over the foramen,  prevents its return, and appears likewise
to preclude its course into the left auricle,  during the systole
of the auricles.  By means of this valve, the foramen gene-
rally  becomes closed, in early infancy, in proportion as the
corresponding Eustachian valve decreases, and it more or
less completely disappears!!.
   629. The  blood which enters the right auricle and ven-
tricle principally  proceeds  from the  superior cava,  and
flows but in  a very  small  quantity into  the lungs,  while,
from the right ventricle, which,  in  the foetus,  is  remarka-
bly thick and strong for this purpose, it pursues its course
  • Eustachius, De vena sine pari. p. 289. Opuscula. tab. viii. fig. 6. tab.
xvi. fig. 3.
  | J. F. Lobslein, De valvula Eustachii. Aug. 1771. 4to.
  | Haller,  De for amine ovali  et  Eustachii  valvula.  Gotting.  1743.
fol. c. f. ae. and much more copiously in his Opera Minora.  T. i.
p. 33. sq.
  § For an account of the opinion of C. Fr.  Wolff*, who regards the
foramen ovale as another mouth of the inferior cava, opening into the
left auricle,  in the same manner as the mouth commonly known opens
into the  right.   Vide Nov. Comment. Acad. Scient. Petropol. t.  xx.
1775.
  || H. Palm. Leveling, De valvula Eustachii et for amine ovali. Anglipol.
1780. 8vo. c. f. ae. 
358       OF THE DIFFERENCES IN THE SYSTEM
directly to the arch  of the aorta,  by means of the ductus
arteriosus*,  which is, as it were, the chief branch of the
pulmonary  artery.    A few  weeks after birth this  duct
becomes obstructed,  and converted into a kind  of dense
ligament.
  630.  The blood of the aorta,  being destined to return, in
a great measure, to the mother, enters the umbilical arteries,
(572) which pass  out on each  side of the urachus, at the
umbilical opening, and, after birth, likewise become imper-
forate chords!.
  631.  As the function of the lungs scarcely exists in the
foetus,  their  appearance  is  extremely different from  what
it is after the  commencement of respiration.   They are
proportionally much smaller,  their  colour is  darker,  their
substance  denser,  consequently their  specific gravity is
greater,  so that, while recent and sound, they sink in water,
while, after birth, they,  ceteris  paribus,  swim upon its
surface!.  The  right lung  has the peculiarity  of dilating
during  the first inspiration rather  sooner than the  left§.
The  other  circumstances  attending the commencement
of  respiration were  described  in  the  section upon  that
function.
  * B. S. Albinus' Annot. Acad. L. ii. tab. vii. fig. 7.
  f v. Haller's Icones Anat. fasc. iv. tab. iii. vi.
  \ This is not the proper place for explaining the conditions under
which this occurs, and the cautions therefore requisite in giving an
opinion in a court of justice, founded on the examination of the lungs.
  Among many other writings, the very important posthumous paper of
Wm. Hunter may be consulted, in the Medical Observ. and Enquiries.
Vol vi. p. 284. sq
  § Portal in the Mem. de I'Acad des Sc. de Paris 1769. p. 555. sq.
  Metzger, De pxlmone dextro  ante sinistrum respirante-  Regiom.
1783 4to. 
BEFORE AND AFTER BIRTH.
359
   632. From our remarks upon the nutrition of the foetus,
 it is clear that  its alimentary tube and chylopoietic system
 must be very peculiar.   Thus, v. c.  in an embryo a few
 months old, the large intestines  very nearly resemble  the
 small;  but during the latter half of pregnancy, being turgid
 with meconium, they really deserve the epithet  by which
 they are commonly distinguished.
   633. The meconium is a saburra, of a brownish green
 colour, formed  evidently from the secreted fluids of  the
 foetus, and chiefly from its bile, because it is first observed
 at the period corresponding to the  first secretion of the bile ;
 and in monstrous cases, where the liver has been absent, no
 meconium, but merely a small quantity of colourless mucus,
 has been found in the intestines.
   634. The cacum is extremely different in the  new born
 child from its future form, and continued straight from the
 appendix vermiformis, &c*
   635. Other similar differences  we have  already spoken
 of, and shall now pass over.  Such are the urachus (573),
 the membrana pupillaris (262), the descent of the testes in
 the male (510, sq.)
   Some will be treated of more properly in the next section.
 Others, of little moment,  we shall entirely omit.
   636.  This is  a favourable   opportunity for briefly no-
 ticing some remarkable parts, which  are, out of all pro-
 portion, larger in the foetus, and appear to serve important
 purposes  in  its economy, although their  true  and prin-
 cipal  design deserves still  further investigation.   They
 are usually styled glands, but their parenchyma is  very
 different from true glandular  structure, nor has any ves-
tige of an  excreting  duct  been  hitherto  discovered  in
• B.S. Albinus' Annotat. Acad. L. vi. tab. ii. fig. 7. 
360       OF THE DIFFERENCES IN THE SYSTEM

them.  They are the thyreoid, the thymus, and the supra-
renal glands*.
   637. The thyreoid gland] is  fixed  upon the cartilage of
the same name belonging to the  larynx, has two  lobes, is, as
it were, lunated!, and full, not  only  of blood,  in which it
abounds in the foetus, but of lymphatic fluid, and  becomes,
as age advances, gradually less juicy§.
   638. The thymus is a white and very tender structure,
likewise bilobular,  sometimes completely  divided into two
parts, occasionally containing a remarkable cavityll, placed
under the superior part of the  middle  of the  sternum,
always ascending  as  far as  the neck  on each side^j, of
extremely great  proportionate size in the foetus, abound-
ing  in  a milky fluid, becoming gradually absorbed in
  * Vide F.  Mechel's  Abhandlungen  aus  der mensehlichen  u.  verg-
leichenden Anatomic Halle. 1806. 8vo.   He makes it probable, that
these three organs contribute to the chemical functions of the nervous
and hepatic systems, and thus diminish the quantity of hydrogen and
carbon.
  j- Cajet. Uttini, De glanduloe thyroidece usu, in the Comment, instituti
Bononiens. Vol. vii. p. 15. sq.
  | Haller's Icones Anat. fasc. iii. tab. 3.
  §J. Ant.  Schmidtmuller, uber die Ausfuhrurgsgunge  der Schilddr'use.
Landshut. 1804. 8vo.
  || Aug. Lud. de Hugo, De glandulis in genere et speciatim de thymo.
Gotting. 1746. 4to. fig. 2.
  Morand the younger, in the Mtmoires de I'Acad. des  Se. de Paris.
1759.  tab. 22—24.
  Vincent Malacarne, !n the Memorie della Societa Italiana. T. viii.
1799.  P. i. p. 239. sq.
  Sam.  Chr. Lucae, Anatomische Untcrsuchungen der Thymus. Francof.
1811.  4to.
  % Haller's Icones Anat. I.e. 
BEFORE AND AFTER BIRTH.
361
youth,  and  frequently  disappearing  altogether  in  old
age.*
  639.  The supra-renal glands, called also renes succen-
turiati and capsulae atrabiliariae,  lie under the diaphragm
on the upper  margin of  the  kidneys,!  ^rom which,  in the
adult,  they are rather more distant, being proportionally
smaller.   They are full of a dark fluid of a more reddish
hue in  the foetus  than in the adult. (A)
                         NOTE.

   (A)  It  is  singular  that Blumenbach  should omit  te
notice one of the most striking peculiarities of the foetus__
the very great proportionate bulk of its  liver.  The pro-
digious  size of this organ arises from the distribution of
four-fifths  of the blood  of the umbilical  vein through it,
and . probably, as some think, in a certain  degree, from the
great  quantity  of meconium in its  biliary ducts.   After
birth, no blood is  conveyed by the umbilical vein, and the
expansion  of the thorax readily expresses the  abundance
of meconium; hence the liver must diminish.
   This peculiarity, as well as the great size of the thyreoid
thymus, and  supra-renal  glands, probably serves  some
purpose hitherto undiscovered, but an  evident good effect
results  from it,  in relation to the organs of the thorax.
  * Hewson's Experimental enquiries. P. iii. passim.
  ! See Eustachius their discoverer. Tab. Lii. iii.  and tab. xii. fig.  I
10. 12.
  Haller's Icones Anat. fasc iii. tab. vi.
  Malacarne, 1. c.
                           A  3 
362     OF THE DIFFERENCES IN THE SYSTEM,  &C.

In  the foetus the  lungs  are completely devoid of air, and
consequently there cannot be much, if any, circulation of
blood  through the  pulmonary artery and  veins, and  the
liver by its  magnitude protruding the  diaphragm upwards
renders  the  capacity of the chest  correspondendy small,
and at the same time it contains an immense proportion of
blood.   After birth, the diminished size of the liver allows
a  great increase to  the  capacity of the  chest;  not only
is full inspiration  allowed, and consequently a free passage
to  the  blood of the pulmonary vessels during inspiration,
as  Haller remarks,* but a certain  degree of permanent
dilatation of the lungs  is allowed, (for much air remains
in  the  lungs after  every expiration), and as the liver con-
tains,  immediately  after birth', so much smaller a portion
of the  blood of  the system than before,  the greatly in-
creased supply required by the  lungs is thus afforded.f
See Note B. Sect. 8.
  * Elementa Physiologix. T. 8.
  ! See Mr. Bryce's excellent paper on this subject in the Edinburgh
Mfd. £? Swg. Journal, 1815, Jan. 
OF THE GROWTH AND DECREASE OF MAN.         563
                    SECT. XLIV.

      OF THE GROWTH, STATIONARY CONDITION, AND
                    DECREASE OF MAN.

  640.. .N otHing more remains at present than to survey
at one view the natural course of the life of man, whose
animal functions we  have hitherto arranged in classes and
examined  individually,  and  to  accompany  him  through
his principal epochs  from his birth  to his grave.*
   641.  The commencement of formation appears to happen
ubout the third week from conception (569), and genuine
blood  is  first observable about the  fourth, the life of the
foetus at this period being extremely faint (82) and almost
merely that of a vegetable ; the  motion  of the heart (98),
under fortunate circumstances, has been  observable  at this
time in the human  embryo,! though  long  ago  detected
by  Aristotle  in  the incubated  egg,! and since  his time
denominated the punctum saliens.
  The original form  of the embryo  is simple,  and, as it
were, disguised, wonderfully different from the perfect con-
 "* Vide Const. Anast. Philites De decremento seu de marasmo senili. Hal.
1808. 8vo.
  t Vide J. De .Muralto,  in the Ephemerides -V. C. Dec.  ii. ann. i. p.
305.
  Roume de St. Laurent, in Rozier's  Obs. et nufm. s. la physique.  Juillet,
1775, p. 53.
  £ Aristotle's Hist. Animal. L. vi. cap. 3. Opera. Vol. ii. p. n>?6. 
364       OF THE GROWTH  AND DECREASE OF  MAS.
4
formation of the human frame, which deserves to  be re-
garded  as  the grandest effect of the nisus formativus, and
at which it arrives  by gradual changes or,  if  we may so
speak,  metamorphoses  from a more simple to a more per-
fect  form.*
   642. The formation  of human  bone]  begins,  if we  are
not  mistaken, in the seventh or  eighth  week.   First  of
  *  Hence,  as I have remarked  in  another place,  (—Nova  Litteraria
 Goettingensia, a. 1808, p. 1386—), human monsters are sometimes  met
 with, so strongly  resembling the form of brutes,  because the nisus for-
 mativus, having  been  disturbed  and obstructed  from some cause or
 other, could not reach the highest pitch of the human form, but rested
 at a lower point  and  produced  a bestial  shape. On the contrary, I
 have never once  found among brutes a true  example of monstrosity,
 which, by a  bound of the nisus formativus,  bore  any analogy to the hu-
 man figure.
  For fuller information  in regard to the resemblance of the very  early
 human embryo to  the larvae  of reptiles, and  in  some measure to the
 foetuses  of quadruped mammalia, consult   after  Harvey  De general.
 animal, p. 184, 235, sq. London, 1651, 4to.—Grew's  Cosmol. sacr. p. 37,
47,_Lister De humoribus. p. 444, and others, especially Autenreith, Ob-
servat. ad  histor. embryon.  faciendum.   P. i. Tubing,  1797, 4to.—Fr.
 Meckel, both in the Auffutz zur menschl. u.  vergleich. anat.  p. 277, sq.
and in the Beytriig zur vergleich. anat. p. 63, and  clsewliere,  and Const.
 Anast. Philites, 1. c.
  + I say of human bone; for in the incubated chick, it commences much
later,__at the beginning of the ninth day, which  corresponds with the
seventeenth -week of human pregnancy.
  Observations,  therefore,  made on  the incubated chick,  must not be
hastily applied to the formation  of the human embryo,—an  error  com-
mitted by the great Iluller himself, who  clearly asserted that what he
had demonstrated in regard to the incubated cluck, -was equally applicable  to
 other classes of animals and to man himself.  -
  This opinion gained so much ground subsequently, that  some   phy-
sicians who endeavoured to settle the  f jrensic  disputes respecting pre- 
          OF THE  GROWTH AND DECREASE  OF MAN.      365

 all, the  osseous fluid forms its nuclei in the clavicles, ribs,
 vertebrae, the  large  cylindrical bones of  the extremities,
 the lower jaw, and  some  other bones of the face, in the
 delicate reticulum of some flat bones of the skull,—of  the
 frontal  and occipital,  but less early in the parietal.  In
 general,  the growth  of the  embryo,  and indeed of  the
 human being  after birth,  is  more rapid as the age is less,
 and vice versa.^K)
   643. About  the middle of  pregnancy, certain fluids be-
 gin to be secreted, as Xhtfat (486) and bile.  In the course
 of the seventh  month,  all the organs of the vital,   natural,
 and animal functions  have made such progress,  that if the
 child happens to be born at this period, it is  called, in  a
 common acceptation of the word,  vital, and regarded as  a
 member of society.
   644. In the foetus,  near its full growth, not only is the
 skin covered by a caseous matter, but delicate hair  appears
 upon the head, and  little nails  become visible;  the  mem-
 brana pupillaris  splits (262);  the  cartilaginous  external
 ear becomes more firm and  elastic; and in the  male  the
 testes descend. (510 et seq.)
   645. About the end of the  tenth lunar month, the child
 being  born,  (595),   undergoes  besides  those  important
 changes of nearly its  whole economy, which were formerlv
 described at large,  other alterations in  its external ap-
pearance ; v. c. the  down which covered  its face at birth,
 gradually disappears,  the wrinkles are obliterated, the anus
 becomes concealed between the swelling nates, Sec.
mature labour, deduced their arguments from this hasty comparison of
the periods of this  incubation  with those of human pregnancy.  Vide
v. c. Hug. Marrcti's  Consultation au  snjet d'un erfant, &c. Divion.
1768, 4to. 
 366     OF THE GROWTH AND  DECREASE OF MAV

   646. By degrees the  infant learns to employ its mental
faculties  of perception,  attention,  reminiscence,  inclina-
 tion, &c.  whence, even  in the early months,  it  dreams,
 and s. p.*
   647. The organs of the external senses  are gradually
 evolved and  perfected,  as the external  ear, the  internal
 nares, the  coverings  of  the eyes, viz.  the supra orbital
 arches, the eyebrows, &c.
   648. The bones of the  skull  unite more firmly;  the fon-
 ticuli  are by degrees  filled  up; and about  eight  months
 after birth,  dentition commences.
   649. At this period the  child is ready to be weaned, its
 teeth being intended  to  manducate solid food  and not to
 injure the mother's breast.
   650. About the end of  the  first year,  it  learns to rest
 upon its feet and stand  erect,—the highest characteristic
 of the human body.!
   651. The  child now  weaned from its mother's breast
 and capable of using its  feet, improves and  acquires more
 voluntary  power daily:  another  grand  privilege of the
 human race  is  bestowed upon it,—the use of speech,—the
 mind  beginning to pronounce, by  means of the  tongue,
the ideas with which it is familiar.
   652. The twenty milk teeth by degrees fall  out about
 the seventh year, and a  second dentition  produces, in the
course of years, thirty-two permanent teeth.
  653.  During  infancy, memory  is more  vigorous  than
  * Consult Ticdcmann  Uber die Entwickelung der seclenf Uhigkeiten bey
Kindem, in the Ilessisch. Beytr.  Vol. ii. P. ii. iii.
  j- (ier.  Vrolik (prxs.  Brugmans) Diss,  de homine  ad statum  gres-
cwnque erectum per corporis fabricam  dispositio.   Ludg.  Bat.  1795,
8vo. 
        OF  THE GROWTH AND DECREASE  OF MAN.      367

the other faculties of the mind, and  much more powerful
• han at  any  other period  in tenaciously receiving  the
impressions of objects :  after  the fifteenth year, the fire of
imagination burns most strongly.
  654. This more lively state of the imagination  occurs
very opportunely  at puberty,  when  the  body, undergoing
various remarkable changes,  is being gradually prepared
for the exercise of the sexual functions.
  655. Immediately after the period when the breasts of
the adolescent girl have begun to swell,  the  chin  of the
boy  is covered with down, and the phenomena of  puberty
manifest themselves in either sex.  The girl begins  to men-
struate, (554),—an important change in the  female  eco-
nomy, accompanied  among other  circumstances,  ncarlv
always by an increased brightness of the eyes and redness
of the lips,  and by more evident sensible qualities of the
perspiration.   The boy begins to secrete genuine semen
(527), and, at the same  time, the beard* grows more abun-
dantly, and the voice becomes remarkably grave.
   By the spontaneous internal voice  of nature, as it were,
the sexual instinct (71) is  now for the  first time  excited,
and  man,  being  in the flower of his age, is capable of
sexual connection.
   656.  The period of puberty cannot be exactly defined:
it varies with climate and temperament,! but is generally
  * The fabulous report, even at this day prevalent,  respecting the
want of beard among some American nations,  I refuted by  a host of
witnesses in the Gotting. Magaz. ann. ii. P. vi. p. 418 et seq. For I
have adduced instances  from the whole of America, both  of nations
who allow their beard to  grow, at least, in part;  and of others,  who,
upon indubitable authority, pluck out  their beard by peculiar instru-
ments, &c.
  ! I have inserted in the Bib!. Medic, vol. i. p. 558 et seq. an account 
368      OF THE GROWTH AND DECREASE OF MAN".
more  early in the  female;  so that  in  our  climate,  girls
arrive at  puberty about the fifteenth year, and young men,
on the contrary, about the twentieth. (B)
   657.  Soon  after  this, growth terminates ; at  various
periods  in different  climates,  to say nothing of particular
individuals and families.* (C)
   658. The epiphyses  of the  bones hitherto distinct from
their diaphyses,  now become intimately united, and, as  it
were, confounded with them.
   659. At manhood,—the longer and more  excellent  pe-
riod of human existence, life  is, with respect to the  cor-
poreal functions, at  the highest  pitch (82), or, in other
words, these  functions  are  performed  with the greatest
vigour and constancy ;  in regard to the  mental functions,
the grand prerogative of mature judgment  is now afforded.
   660. The approach of old  age] is announced in women
by the cessation of the catamenia (556), and not unfre-
communicated to me by G. E. ab Haller, of procreation  in a Swiss girl
only nine years of age.
  * For man has no peculiar privileges of not experiencing the effects of
climate in common with other organized bodies, which are commonly
known to arrive at their growth much later, caeteris paribus,  in cold than
in warm climates.
  As to the  giants of Patagonia  and  the dwarfs of  Madagascar, men-
tioned by Commerson, I have reduced the exaggerated accounts of the
former to a true statement, and have  shewn that the  latter are diseased
Cretins, in my Treatise De gen. hum. var nativ. p. 253, 260. ed. 3.
  | J. Bern. Fischer's Tract, de senio ejusque morbis. Ed. 2. Erf. 1760,
8vo.
  Benj. Rush's  Medical Inquiries & Observations.  Vol. ii.  Philadel.
1793, 8vo. p. 295, sq.
  Burc. W. Seder's Anatomix c. h. senilis specimen. Erlang. 1799, 8vo.
Const. Anast. Philites. 1. c. 
          OF THE GROWTH  AND DECREASE OF MAN.        369

fluently by an appearance of  beard upon  the chin;* in
men,  by  less alacrity to copulate :  in  both, by a senile!
dryness  and   a   gradually  manifested  decrease  of  vital
energy.
   661. Lastly, the frigid  condition of  old age is  accom-
panied by an increasing  dulness of both the  external and
internal senses, a  necessity for longer sleep,  and  a torpor
of all  the functions of the  animal economy.   The hairs
grow  white and partly fall off.  The teeth gradually drop
out.   The neck  is no  longer  able to  give due support to
the  head,  nor the legs  to the  body.    Even  the  bones
themselves—the  props of the machine—in a manner waste
away, he]
   662. Thus we are conducted to the ultimate line of phy-
siology,—to death without disease,^ to the senile tv$<*.va.<rt*.,
which it is the first  and  last object of  medicine  to  pro-
cure, and  the cause of which  must be self-evident from
our preceding account of  the animal economy.^}
   * Vide J. Burlin. De fxminis ex suppressione mensium barbatis.  Altorf,
 1664,4to.   This remarkable phenomenon, which deserves further in-
 vestigation, is  analogous to a change frequently remarked in  female
 birds, which, after ceasing to lay eggs, lose the feathers peculiar to their
»sex and acquire those characteristic of the male.  Examples of this oc-
 cur in the columba cenas, phasianus colchicus,  pavo cristatus, otis  tarda,
 pipra rupicsla, anas boschas, &c.
   ! Joach. II. Gernet. De siccitatis senilis effectibus. Lips. 1753, 4'o.
   % I do not here repeat what I have said at  large in my  osteological
 Work, p. 36, sq. upon the remarkable wasting of the bones of old men.
   § G. Gottl. Richter. De morte sine morbo.  Gotting. 1736, 4to.
   •fl J. Oo3terdyk Schacht.  Tr. qua senile fatum  inevitabili necessitate ex
 hum. corp. mechanismo sequi demonstratur.  Ultraj. 1729, 4to.
   Matt. Van  Geuns  De  morte corporea et causis moriend'. L. B. 1761, 4to.
 reprinted in Sandifort's Thesaurus, vol. iii:
                               B  3 
376       OF THE GROWTH AND DECREASE OF MAN.

   663. The phenomena  of a moribund  person* are cold-
ness of the extremities, loss of brilliancy in the eyes, small-
ness and  slowness of the pulse, which  more and more fre-
quently  intermits, infrequency of respiration,  which  at
length terminates forever by a deep expiration. •
   In the  dissection  of  other  moribund  mammalia  the
struggle of the  heart may be perceived; and  the right
auricle and ventricle  are found to live rather longer  than
the left, (117).
   66I. Death  is manifested by the  coldness and rigidity
of the body, the flaccidity of the cornea, the open state of
the  anus, the lividness of the  back,  the depression and
flatness of  the  loins  (59, Note),  and  above  all,  by  an
odour truly  cadaverous.!   If these  collective  marks are
present, there  can be  scarcely room for the complaint  of
Pliny, that one ought not to  believe even  a dead man.!
   665. It is  scarcely possible to  define the natural  period
of life, or, as it may  be termed,  the  more  frequent and
regular limit of  advanced  old age.§  But by an accurate
  C.  G. Ontyd. De morte et varia moriendi ratione.  Lugd. Bat. 1791
8vo.
  Curt. Sprengel's Instit. medic. T. 1. Amst. 1809, p. 289, sq.
  • See the successive  progress of the phenomena of death observed in
himself, a man of middle age, dying of dysentery, in Moritz magaz. zur
Erfahrungs Seden-Kunde.  vol. i. P. I. p. 63, sq.            .
  ! Durondeau in the Nouveaux Me'm. de VAc. de Bmxellcs. vol. i. 1788
p.i.
   i C. Himly's Commentatio (which gained the royal prize) mortis his-
toriam causas et signa sistens.  Gotting. 1794, 4to.
  Sol. Anschel's Tkanatologia s. in mortis naturam, causas, genera, species,
et diognosin disquisitiones, il>. 1795, 8vo.
  § Among other well known treatises on this subject, consult J. Gesner
De termino vitx.  Tigur.  1743, reprinted  in the Excerptum Italicx  et
Hdveticx litterat- 1759,  T. iv. 
          OF THE GROWTH AND DECREASE OF MAN.      371

examination of numerous bills of mortality,  I have ascer-
tained a remarkable  fact,—that  a very large proportion of
Europeans  reach  their eighty-fourth year,  while,  on the
contrary, few exceed it (D).
  666.  On  the  whole, notwithstanding  the weakness  of
children, the  intemperapce  of adults, the violence of dis-
eases,  the fatality of accidents,  and  many  other circum-
stances,  prevent  more than perhaps seventy-eight persons
out of a thousand from dying of old age, without disease,
nevertheless,  if human longevity*  be compared,  caeteris
paribus, with the duration of the life of any other known
animal  among the mammalia, we  shall find that of all the
sophistical whinings  about the misery of human life, no
one is more unfounded than that which is commonly made
respecting the shortness of its duration (E).
                        NOTES.

   (A) For a minute account of ossification 1 refer to Mr.
Howship's papers  in the sixth and seventh volumes of the
Medico-Chirurgical Transactions, and more particularly to
a review of the first paper in the first number of the Annals
of Medicine and Surgery.
  (B) Instances  continually occur  in both sexes of early
puberty,  sometimes joined with very rapid growth.   The
  * Bacon de Verulamio.  Historia vitx et mortis. Opera, vol. ii. p. 121,
sq. London, 1?40, fol.
  Chr. W. Hufeland's Makrobhtik^ T. 1. p 90. and elsewhere.  Edit. 3
■805. 
372       OF THE GROWTH AND DECREASE OF MAN.

mind however does not usually keep pace with the body,
(or rather  the brain with the rest of the body)  and such
individuals have commonly  short lives.   Some males arc
reported  to  have  been  adult  before  the completion of
their  first year.  One  of the  earliest examples of female
puberty  is   given   in  the  Medico-Chirurgical  Transac-
tions  :*  the  girl began to  menstruate  when  not  three
vears of  age, and  soon  after acquired large breasts, broad
hips,  Sec.  Schurig relates that  a little couple, each nine
years of  age, married and begot a son.f
   The  activity of the grand organs of  generation,—of the
testes  in the male  and  the ovaria  in the  female, pro-
duces  the  great changes  in the  rest of  the generative
organs  and  in the system at large at the period of puberty,
for  if  they  are previously  removed, these  changes  do
not   occur,   and  they   appear   in   general   proportional
to the  evolution and activity of those organs.!  This is
well  known  in regard  to animals and  man.   We perhaps
have no  well  authenticated  instance  of  the  castration ot
a woman,§  but  when  the ovaria  have been  found  defici-
ent,  the   signs  of  puberty  have  not  appeared,^  while
            * Vol. iv.            ! Spermatal. p. 186.
  t I say generally, because, for instance, the greatest evolution  of the
testes is often accompanied either with little  beard, or a small  larynx,
or some analogous circumstance, while the other marks of manhood are
strikingly manifested •,  and vice versa.   A boy only six years of age
vithoiit any premature evolution of the organs of generation, is recorded
to have had a beard.  Philos. Trans, vol 19.
  § A castrator of sows and other animals in Germany  is said to have
been  so enraged with his daughter for giving  loose reins to her passions,
as to have resolved to extinguish them, and to have completely sue
ceeded by removing her ovaria.  " Ita  bilis mot a est, ut aperto latere
castraret  pullam, quam ab eo tempore nulla testigit veneris cupido."
Cocrhaave's Prxlect. Acad. T. vi. p. 127
   fl Philos.■Trans, vol.95. 
        OF THE GROWTH AND  DECREASE  OF MAX.     S73

the absence of  the  uterus  has not been attended by any
deficiency in  the  general  changes.*  I  must think with
Moreau]  that  many phenomena have  been  ascribed  to
sympathy with  the  uterus  which are really  referrible  to
the ovaria.
   Mr. Hunter made an experiment respecting the removal
of  one  ovarium only.   He took two young  sows in  all
respects  similar to  each  other,  and after removing  an
ovarium  from one he admitted a boar of the same farrow
to each and allowed  them to breed.  The perfect sow bred
till she was about  eight years old,—a period  of almost six
years, in which time she  had thirteen farrows, and in  all
one hundred and  sixty-two pigs;  the other bred till she
was six years  old,—during  a space of more than  four
years, and in that  time she  had eight  farrows and in  all
seventy-six pigs.  Thus  it would appear that each ovarium
is destined to produce a certain number only of foetuses,
and that  the removal of one, although  it does not influ-
ence  the  number  of foetuses produced by the other, causes
them to be produced in a shorter time.!
   (C) Not only  do instances  of early  puberty and full
growth  frequently  occur,  but likewise  of deficient and
exuberant growth.   Dwarfs  are  generally  born  of the
same size as other children, but after  a few years  they
suddenly cease  to grow.  They are said to be  commonly
ill-shaped, to have large heads, and to be stupid or mali-
cious,^ and  old age comes upon them  very early.  The
  * Memoires de la Societe1 Me'dicale dyEmulation. Paris. Tom. 2.
  f Hist aire naturelle de la femme. T. 3.
  * An experiment to  determine the effect of extirpating one ovarium upon
the number of young produced.  Obs- p. 157-
  § «It will not be easy to produce me an instance of any one giant or of 
 S74     OF  THE  GROWTH  AND  DECREASE OF MAN.

 three foreign dwarfs  lately exhibited in London, two men
 and one woman, had certainly large heads and  flat noses,
 but in other respects were well made.  The tallest of the
 three seemed  a sulky  creature, but the woman was very
 ingenious and obliging, and Simon  Paap, the least of the
 three,  appeared   very  amiable.   He  was  twenty-eight
 inches  high and  twenty-six years old.   They were not re-
 lated to  each other, and  the  relations of all were of the
 common size.  Their  countenances were those  of persons
 more advanced.  The  smallest dwarf on  record was only
 sixteen inches  high, when thirty-seven years of age.*
   The  tallest  person authentically  recorded has never ex-
 ceeded nine  feet,  according to Haller.
   The  young  man from Huntingdonshire also lately exhi-
bited in  London was  of  remarkable height.   Although
only  seventeen ydars  of  age,  he  was  nearly eight feet.
 He had a sister of extraordinary height, and many of his
family  were very tall.   He was, as is usual,  bom of the
ordinary  size,  but soon began  to grow rapidly.  He  ap-
peared  amiable,  and  as acute as most youths of his age
and rank.  Giants and dwarfs providentially seldom reach
their  fortieth  year and have  not  very  aetive  organs  of
generation.!
any one dwarf perfectly sound in heart and mind, i. e. in the same degree
with a thousand other individuals who are regularly constituted.  Great
mental weakness is the usual portion of giants, gross stupidity that of
dwarfs."  Lavater's Physiognomy.
  • Haller. Elementa Physiologix. T. 12. lib. 30.
  | As the period of growth is so short  in dwarfs, and the period of
childhood so short in those who reach puberty early, it is to be expected
that their old age will be premature—thajt their stationary period and
decline will  be likewise short.  Giants do not, like dwarfs, 1  believe,
die from premature old age, but from exhaustion,- 
        OF THE GROWTH AIM) DECREASE OF MAN.     375

  (D) Our countryman  Parr married when  a  hundred
and twenty years of age, retained his vigour till a hundred
and forty,  and died at a hundred and fifty-two from  ple-
thora induced by a change  in his diet.  Harvey who  dis-
sected him, found no decay of any organ,*  and had  not
Parr become an inmate of the Earl of Arundel's  family in
London, he probably would have lived many years longer.
Our  other  countrymen  Jenkins, who  lived  a hundred
and  sixty-nine  years,  is  perhaps the  greatest  authentic
instance of longevity.
   It  is unnecessary to observe  that the height and the
age of men at present are the same as  they have been for
thousands  of years.  It is  a common custom to magnify
the past.   Homer who flourished almost  three  thousand
years ago, makes his heroes hurl stones in battle which
                 i      oo'  tv'o y* a.niS^t pi'go/eii

   Yet  the  giant who was the terror of the  Israelites,  was
not probably more than nine feet in  height,  and  David,
who  slew him, and was  nearly cotemporary with Homer's
heroes, says,  " The days of our years are threescore and
ten;   and if by  reason  of strength  they be  forescore
years,  yet is  their strength labour and sorrow;  for  it  is
soon  cut off and we fly away."!
   (E)  The functions of  the human  machine having  now
been  fully described,  it may be  of advantage to consider
it in its relation to other  animated systems, and to review
the chief varieties in which it appears.
  Hopkins Hopkins, -weighing never more than 181bs. and latterly but
12, died of pure old age at seventeen, and one of his sisters, but twelve
years of age and  weighing only I81bs. at the time of her death had all
the marks of old age.  Gentleman's Magazine,  vol. 24, p. 191.
  * Philos. Trans, vol. 3 16??.      t Iliad, lib. S.      t Psalm 9«. 
SI6              GRADATION OF OBJECTS,

   Numerous authors   have  remarked that  a  gradation
 exists among all the objects of the universe,  from the Al-
mighty Creator,  through  arch-angels and angels,  men,
animals, vegetables and inanimate matter, down to nothing.
          " Vast chain of being which from God began,
            Natures ethereal, human, angel, man,
            Beast, bird, fish, insect, what no eye can see,
            No glass can reach, from infinite to thee,
            From thee to nothing."*
  Yet this gradation deserves not the epithet regular or in-
sensible.  " The highest being not infinite must be, as has
been often observed, at an infinite distance below infinity."
" And in this distance  between finite and. infinite there  will
be room for ever for an infinite series of indefinable exist-
ence.   Between the lowest positive existence and nothing,
wherever we suppose existence to cease,  is another chasm
infinitely deep;  where there is room  again  for  endless
orders  of  subordinate  beings,  continued  for ever   and
ever,   and yet infinitely superior to non-existence."  " Nor
is  this all.   In the scale, wherever it begins or ends,  are
infinite vacuities.  At whatever distance we suppose  the
next order of beings to be above man,  there  is room  for
an intermediate  order of beings between them, and if for
one order then for infinite  orders ;  since every thing that
admits of more  or less,  and consequently all the  parts of
that which  admits  them,  may be infinitely divided.  So
that as far  as we  can  judge, there may be room in  the
vacuity, between any two steps of the scale,  or  between
any two points of the cone,  for infinite exertion of infinite
power."!
  * Pope's Essay on Man, Epistle 1.
  f Dr. Johnson's Rcviezv of a Fret Enquiry into the nature and origin oj
nil. 
INANIMATE BODIES.
   In  fact,  at  how vast a distance do we  see the innate
 mental properties of man  standing  above those of the
 most sagacious animal: how immensely does the volition
 of the lowest animal raise it above the whole vegetable
 kingdom ;  and how deep  the chasm  between the vital
 organisation of the meanest vegetable and a mass of in-
 animate matter.   Gradation must be admitted, but it  is
 far from regular or insensible.  Neither does  it regard
 the perfection, nor so much the degree, but the excellence
 and combination, of properties,—man, placed at the sum-
 mit of the terrestrial gradation, by the excellence of his
 mind and the combination of the  common properties of
 matter, of those  of vegetables and of those  of animals,
 with those  peculiar to himself, is surpassed by the dog
 in acuteness of smell and by the oak in magnitude, nor is
 he more perfect than the gnat or the thistle in its kind.
   Bodies consist of particles endowed with certain pro-
 perties, without which their existence cannot be conceiv-
 ed, viz. extension and impenetrability; with others which
 proceed indeed from their existence,  but are capable of
 being  subdued by opposing energies,  viz. mobility, in-
 ertness ; and  with others neither necessary to their ex-
 istence nor flowing from it, but merely superadded; for
 example,  various attractions  and repulsions,  various
 powers of affecting animated systems.
  Inanimate bodies have no properties which arc not ei-
ther analogous to these or dependent upon them ; are for
the most part  homogeneous  in their composition, and
disposed to be flat and angular, increase by external ac-
cretion, and contain within themselves no causes of
decay.
  Vegetables, in  addition to the properties  of inanimate
matter, possess those of Life, viz. sensibility  (without
                         C .1 
378
VEGETABLES.
perception) and contractility ;* their structure is beauti-
fully organized, and their surfaces disposed to be round-
ed ;  they grow by internal deposition,  and  are destined
in their nature for a period of increase and  decay.
   Animals, in  addition to the properties  of vegetables,
enjoy Mind, the indispensable attributes of which are,
the powers of consciousness,  perception, and volition ;
the two former without the latter were, like vegetable or
organic sensibility without contractility, useless, and the
latter could not exist without the two former, any more
than vegetable  or organic contraction could occur with-
out sensibility; nor can the existence of  mind  be con-
ceived without the faculties of consciousness, perception,
and volition, any  more than the existence of matter with-
out  extension and impenetrability.  The possession of
mind by animals necessarily implies the presence 'of a
brain for its performance, and of a  nerve or nerves for
the purpose of j conveying impressions  to this brain, and
volitions from it  to one  or more voluntary muscles.   A
system which  is  not thus gifted certainly deserves  not
the name of animal.!
  * By the former,  stimuli act upon them,  and by the latter, they
upon stimuli:—by the sensibility and contractility of the vessels, sub-
stances are taken up by the roots, circulated through the system, and
converted into the various parts of the vegetable.  Yet this does not
imply perception or will; the sensibility and contractility of the ab-
sorbents and secretories of our own system  carry on absorption and
secretion without our consciousness or volition.
  j I cannot conceive an animal without perception and volition; nor
can I conceive these in an animal without a brain, any more than the
secretion of bile without a liver, or something analogous.  I contend
not for the name, but the thing.  Comparative anatomists indeed af-
firm,  that many  internal worms and all the class of zoophytes have no
nervous system.  But comparative anatomy is yet imperfect, the ex^. 
ANIMALS.
379
   Notwithstanding the vast interval which of necessity
exists between the animal and vegetable  kingdoms, the
lowest animals approach as nearly as possible in organi-
sation, and consequently in function, to vegetable simpli
city. They possess merely consciousness, perception and
volition, with the instinct for taking food, and multiply by
shoots,  fixed like vegetables  to  the  spot which tLey in-
habit.   The five  senses, instincts, memory,  judgment,*
amination of minute parts is extremely difficult, and new organs are
daily discovered.  Blumenbach, after  remarking that, except those
animals which inhabit corals, and the proper zoophytes, most genera
of the other orders of  the class of vermes are found to possess a dis-
tinct nervous system, adds: "Although former anatomists have ex-
pressly declared  in several instances  that no such  parts existed."
(Comparative Anatomy, cxvi. F.) Again, some beings are denominat-
ed animals without any very satisfactory reason.  Where the nervous
system of an animal cannot be readily detected,  its presence may be
inferred from motions evidently voluntary,  such  as the  retraction of
worms into  the earth upon the approach of footsteps,  proving the ex-
istence of an organ of hearing, a brain and nerves ; motion in a part
directly stimulated, as the contraction of an hydatid upon being punc-
tured, is no proof of an animal nature, for this is common to vegeta-
bles, for instance, the leaves of the Dionxa Muscipnla, which contract
forcibly on  a  slight irritation.  It may likewise be inferred from the
presence of a stomach, because where  there is a stomach, the food is
taken in, not by absorbing vessels constantly plunged in it, but by a
more or less complicated and generally solitary opening regulated by
volition.  John Hunter contended that the stomach was the grand
characteristic of the animal kingdom.
  * I see daily instances of reason in animals;  to the  sceptical 1 offer
the following anecdote, in the words of Darwin.  " A wasp on a gravel
walk had caught atfy nearly as large as itself. Kneeling on the ground,
I observed him separate the tail and the head from the body part, to
which the wings were  attached.  Ik- then took the body part in  his
paws and rose about two feet from the ground with it;  but  a gentle 
u80
ANIMALS.
and locomotive power,  with  the  necessary  organs,  arc
variously superadded, and endless varieties of organiza-
tion constructed, so that air and water, the substance and
the surface of the earth, are all replenished with animals
calculated  for their respective habitations.*
 breeze, wafting the wings of the fly, turned him round in the air, and
 he settled again with his prey upon the gravel.  I then distinctly ob-
 served him cutoff with his mouth  first one of the wings and then the
 other, after which he flew away with it, unmolested with the wind."
 Darwin's Zoonomia.—Instinct.  Consult the works of the two Hubers
 Stir les abei/es and Sur les fourmis.
   * An error has been committed, not only in supposing the  gradation
 regular, but in supposing every  species of  animal to constitute a dis-
 tinct step in the gradation.   "The whole chasm in nature," says Ad-
 dison, ("Spectator, JYo. 519, J " from a plant to a man, is filled up with
 divers kinds of creatures, rising one above another, by such a gentle
 and easy ascent, that the little transitions and deviations from one
 species to another are almost insensible."  " All quite down  from us,"
 remarks Locke, (Essay on the Human Understanding, B. 3. c. 6.J
 " the descent is by easy steps,  and a continued series of things, that
 in each remove differ very little one from the other.  There  are fishes
 that have wings, and are not strangers to the airy region; and there
 are some birds, that are inhabitants of the water, whose blood is  cold
 as fishes, and their flesh so like  in taste, that  the scrupulous  are al-
 lowed them on fish days.  There are animals so near of kin both to
 birds and beasts,  that  they are in the middle between both: amphi-
 bious animals link the terrestrial and aquatic together, seals live at
 land and at sea, and porpoises have the  warm blood and entrails  of a
hog; not to mention what is confidently reported of mermaids or sea-
 men."   Now the various kinds of animals  do certainly run  into each
 other; no two  are so different, but that daily discoveries are made of
 a third intermediate.  But connection is not gradation.  Many kinds,
 for instance, birds and beasts,  and the intermediate ones  by which
 they are united, are all on a level  in point of excellence, so  that  a
 single step in the gradation may comprehend a great number  of kinds ;
 —the whole vegetable kingdom  forms but one step. 
MAN.
381
  Man, besides the common properties of animals, has
others, which raise him to an immense superiority.  His
mind is endowed with powers of the highest order which
they have not, and his body being, like the bodies of all
animals, constituted in harmony with the mind, that the
powers of the latter may have effect, differs  necessarily
in many points of construction from the body of every
animal.  Well might the greatest of all uninspired poets
exclaim, " What a piece of work is man ! How noble in
reason! how infinite in faculties!  in form and moving
how express and admirable ! in action how like an angel!
in apprehension how like a god ! the beauty of the world !
the paragon of animals !"*
  The true  ourang-outang (simia  satyrus)  approaches
the nearest of all animals to the human subject. Curious,
imitative, covetous, social, placing sentinels  and dispos-
ing themselves in a train  for the propagation  of alarm,
sometimes seeming to laugh,! walking occasionally erect,
defending themselves with sticks and stones, copulating
face to face,! carrying their  young either in their arms
or on their backs, possessing  teeth of the same number
and figure as our own,  and very lascivious in regard to
our species, the ourang-outangs at first sight afford, if any
 if the genus can afford, a little probability to the  opinion
of a close connection between monkeys  and the human
race.   Uncivilized men, too, make a slight approach in
many corporeal particulars, as we  shall hereafter find, to
  * Shakspeare. Hamlet.  Act 2, Sc. 2.
  ! Le Cat (Traite" de VExistence du fluide des nerfs. p. 35,J  asserts
'hat he had seen the jocko (Simia TroglotydesJ both laugh and cry
■  f Fouchc d'Obsonville.  Obs. pV'nr sur les mcevrs d'anim. etra7tger'
p. 167 
 382     MENTAL CHARACTERISTICS OF MAN.

the structure of other animals, and since also the circum-
stances of their existence call into action few of the pecu-
liar mental powers of our nature, they have been adduced
in corroboration of this opinion. But an attentive exami-
nation displays differences of the greatest magnitude be-
tween the human and the brute creation. These we shall
review under two divisions, the first embracing the mental,
and the second the corporeal characteristics  of mankind.
   In judging  of the  mental faculties of mankind, not
merely those should be considered which an unfortunately
situated individual may display, but those which all the
race would display, under favourable circumstances.  A
seed and a pebble may not on a shelf appear very dissi-
milar, but if both are placed in the earth, the innate cha-
racteristic energies of the seed soon become conspicuous.
A savage may in the same manner seem little superior to
an ourang-outang, but if instruction is afforded to both,
the former will gradually develop the powers of our na-
ture in all their noble superiority, while the latter will
still remain an  ourang-outang.  The excellence of man's
mind demonstrates itself by his voice and hands.   Wit-
ness the infinite variety and the depth of thought express-
ed by means of words : witness his greafreasoning pow-
ers, his ingenuity, his taste, his conscientious,  religious,
and benevolent  feelings, in his manufactories, his galleries
of the fine arts, his halls of justice, his temples, and his
charitable establishments. Besides the qualities common
to all animals, each of which he, like every animal,  pos-
sesses  in a degree peculiar to himself, and some indeed
in a degree very far surpassing that in  which any animal
possesses  them, for instance, benevolence, mechanical
contrivance,  the sense for music, and the general power
of observation and inference, he appears exclusively gifted 
CORPOREAL  CHARACTERISTICS OF  MAN.
383
with feelings of religion and jtfstice, with taste, with wit,
and with the faculty of comparing things, and diving into
their causes.*
   The corporeal characteristics of mankind are not less
striking and noble.!  Among the beings beheld by Satan
in  Paradise,
           " Two of far nobler shape, erect and tall,
           Godlike erect, with native honour clad
           In naked majesty seemed lords of all."*

   The erect posture is.natural and peculiar to man.§  All
nations walk erect, and among those  individuals who
have been discovered in  a wild and solitary state, there
is no well authenticated instance of  one whose progres-
sion was on all fours.   If we attempt this mode  of pro-
  * Consult Spurzheim's System of Physiognomy, passim.
  ! Consult  Blumenbach's Treatise De Generis  Humani Varietate
Nativa.  Sect. 1.  De hominis a coeteris animalibus differentia.
  t Milton's Paradise Lost.  Book iv. 288.
  § There is no necessity to attempt the refutation of the ridiculous
opinion, that man is destined to walk on all fours. But I do so for the
purpose of displaying many peculiarities of our structure.
  It is almost incredible that any thinking man could have entertain-
ed it for a moment. Yet such is the fact, and it was in vain even that
Hudibras, after proving to his mistress  by his beard that he was no
gelding, urged his erect posture in proof that he was not a horse.
           " Next it appears I am no horse,
           That I can argue and discourse,
           Have but two legs, and ne'er a tail—
           Quoth she, That nothing will avail;
           For some philosophers of late here
           Write, men have four legs by nature,
           And that 'tis custom  makes them go,
           Erroneously but upon two."
                             Hubidras.  Part ii. Canto I. 
384    C0RP0R1.AL CHARACTERISTICS OF  MAN.

gression, we move either On the knees or the points of the
toes, throwing the legs obliquely back to a considerable
distance; we find ourselves insecure and uneasy; our eyes,
instead of looking forwards, are directed to the ground;
and the openings of the nostrils are no longer at the lower
part of the nose, in a situation to receive ascending odo-
rous particles, but lie behind it. Our inferior extremities
being of much greater length in proportion to the superior,
and the trunk than the posterior, of animals with four ex-
tremities, even in children in whom the proportion is less,
are evidently not intended to coincide with them in move-
ment;  they are much stronger than the arms, obviously
for the purpose of great support; the presence of calves,
which are found in man alone, shews that the legs are to
support and move the whole machine; the thigh bones are
in the same line with the trunk ; in quadrupeds they form
an acute angle; the bones of the tarsus  become hard and
perfect sooner than those of the carpus, because strength
of leg  is required for standing and walking  sooner than
strength of arm and hand for labour; the great toe is of
the highest importance to the erect posture, and is be-
stowed exclusively on mankind.   The  superior extremi-
ties do not lie under the trunk, as they would if destined
for its support, but on its sides, capable of motion towards
objects in every direction ; thet fore arm  extends itself
outwards, not forwards, as in quadrupeds, where it is an
organ of progression; the hand is fixed not at right angles
with the arm, as an instrument of support, but in the
same line, and cannot be  extended to a right angle with-
out painfully stretching the flexor tendons ; the superior
extremity is calculated in the erect posture for seizing and
handling objects, by the freedom  of its motions, by the
^-ent length of the fingers above that of the foes, and by 
       CORPOREAL CHARACTERISTICS  OF MAN.    385

the existence of the thumb, which, standing at a distance
from the fingers, and bending towards them, acts as an
opponent, while the great toe is, like the rest, too short
for apprehension, stands in the same line w ith them, and
moves in the same direction.   Quadrupeds have a strong
ligament at the back of the  neck, to sustain the head; in
us there is no such thing, and our extensor muscles at the
back  of  the neck are comparatively very weak.*  They
have the thorax deep and narrow, that the anterior ex-
tremities may lie near together, and  give more support;
the sternum too is longer, and the ribs  extend consider-
ably towards the pelvis, to maintain the  incumbent visce-
ra ; our thorax is  broad from side to side, that the arms,
being thrown to a distance,  may have  greater extent of
motion,  and riarrow from the sternum to the spine ;  and
the abdominal viscera, pressing towards the pelvis, rather
than towards the surface of the abdomen, in the erect at-
titude, do not here require an osseous support. The pelvis
is beautifully adapted in us for supporting the bowels in
the erect posture ;  it is extremely expanded, and the sa-
crum and os coccygis bend forwards below : in  animals it
does not merit the name  of pelvis;  for, not  having to
support the abdominal contents, it is  narrow,  and the
sacrum inclines but little to  the pubis. The nates, besides
extending the pelvis upon the  thigh  bones in  the erect
  * As the head is connected with the trunk farther back in animals
than in us, the small length of lever between the occipital foramen
and the back of the head, and the length of the head below  the fora-
men, require all this power; but in us, much more upholding power
than we have at the back of the neck would be required for all-four
progression, as the spine would be connected with the head horizon
tally.
                         n s 
386    CORPOREAL CHARACTERISTICS OF  MAN.

state of standing or walking, allow us to rest while awake
in the sitting posture, in which the head and trunk being
still erect, our organs of sense have their proper direction
equally as in walking or standing: were we compelled to
lie down like brutes,  while resting  during the waking
state, the different organs of the face must  change their
present situation, to retain their present utility, no less
than if we were compelled to adopt the horizontal pro-
gression ; and, conversely, were their situation so chang-
ed, the provision for the sitting posture would be com-
paratively useless.
   While some, perversely desirous of degrading their
race, have attempted to remove  a  grand source of dis-
tinction, by asserting that we are constructed for all fours,
others,  with equal perverseness and ignorance, have as-
serted that monkeys are destined for the upright posture.
Monkeys, it is true, maintain the erect posture less awk-
wardly than other animals with four extremities, but they
cannot maintain it long, and, while in it, they bend their
knees and body; they are insecure and tottering, and glad
to rest upon  a stick;  their feet, too, instead of being
spread for support, are coiled up, as if to grasp some-
thing.  In fact, their structure proves them to be neither
biped nor quadruped,  but four-handed animals.  They
live  naturally in trees, and are furnished with four hands
for grasping the branches and gathering their food.  Of
their four hands, the posterior are even the more perfect,
and  are in no instance destitute of a  thumb,  although,
like  the thumbs of all the quadrumana, so  insignificant,
as to have been termed by Eustachius " omnino  ridicn-
lus ;" whereas the fore hands of one variety (simia pa-
niscus) have not this organ.
   It vas anciently supposed that man, because gifted with 
         CORPOREAL CHARACTERISTICS OF MAN.   387

the highest mental endowments, possessed the largest of
all brains.*  But as elephants and whales surpass him in
this respect, and the  sagacious  monkey and dog  have
smaller brains than the comparatively stupid ass, ox and
hog, the opinion was  relinquished by the moderns, and
man was said only  to  have the largest brain in propor-
tion to the size of his body.  But as more extensive ob-
servation proved canary and other birds, and some va-
rieties of the monkey tribe, to have larger  brains than
man in proportion to the body, and several mammalia to
equal him in this particular, and as  rats and mice too
surpass the dog, the horse, and the elephant, in the com-
parative bulk of their brains, this opinion gave way, in
its  turn, to that of Soemmerring,—that man possesses
the largest brain, in comparison with the nerves arising
from it.  This has not yet been contradicted, although
the  comparative size of the brain to the nerves origin-
ating from  it,  (granting that they originate from it)  is
not an accurate  measure of the faculties, because the seal
has in proportion to  its nerves  a larger brain than the
house dog, and  the porpoise than the ourang-outang.
   As the human brain is of such great comparative mag-
nitude, the cranium is necessarily very large, and bears  a
greater proportion to the face than in any animal.  In an
European, a  vertical section of the  cranium is almost
four times larger than that of the face, (not including the
lower jaw); in the monkey, it is little more than double ;
in most feres, nearly equal; in the glires, solipedes, pe-
cora and belluse, less.  The faculties,  however, do not
depend  upon this proportion,  because men  of great ge-
  * Consult Spurzheim, 1. c. on the correspondence  between the
mind and the proportion of the brain in several particulars. 
388     CORPOREAL CHARACTERISTICS OF MAN.

nius, as Leo, Montaigne, Leibnitz,  Haller, and  Mira-
beau, had very large faces, and the sloth  and seal have
faces larger than the stag, horse, and ox,  in proportion
to the brain, and the proportion is- acknowledged by Cu-
vier to be not at all applicable to birds.  We are assist-
ed in discovering the proportion between the  cranium
and face by the  facial angle of Camper.  He draws two
straight lines, the  one horizontal, passing through the
external meatus auditorius and the bottom of the nos-
trils, the  other  more perpendicular,  running  from the
convexity of the forehead to the most prominent part of
the upper jaw.   The angle which the latter,—the proper
facial line, makes with the former, is least in the human
subject, from the comparative  smallness of the  brain and
the great developement of#the mouth and nose in ani-
mals.   In the human  adult this angle is 85°; in the
ourang-outang 67°; in some quadrupeds 20°; and in the
lower classes of vertebral animals, it entirely disappears.
  Neither is it to be regarded as an exact measure of the
understanding, for persons of  great intellect may have a
prominent mouth; it shows merely the projection of the
forehead, while the cranium and brain may vary greatly
in size in other parts; three-fourths  of quadrupeds,
whose  crania differ extremely in other respects, have the
same facial angle; great amplitude of the frontal sinuses,
as in the owl and hog, without any increase of brain,
may diminish  it, and for this  reason  Cuvier draws the
facial line from  the internal table of the frontal bone.
  In proportion as the  face is elongated, the  occipital
foramen lies more posteriorly; in man consequently it is
most forward.   While in man it is nearly in the  centre
of the base of the cranium, and horizontal, and has even
sometimes its anterior margin  elevated, in most quadru- 
       CORPOREAL CHARACTERISTICS OF MAN.    389

peds it is  situated at the extremity of the cranium ob-
liquely, with its posterior parts turned upwards, and is
in some completely vertical.  On this difference of situa-
tion, Daubenton founded his occipital angle.*  He drew
one line from the posterior  edge of the foramen to the
lower  edge of the orbit, and another in the direction of
the foramen, passing between the condyles, and intersect-
ing the former.  According to the angle formed, he es-
tablished the similarity  and  diversity of crania.  The in-
formation derived from it  in  this respect  is very im-
perfect, because it shows the differences of the occiput
merely.  Blumenbach remarks, that its variations are in-
cluded between 80° and 90° in most quadrupeds, which
differ very essentially in other points.
   The want of the  os intermaxillare  has been thought
peculiar to mankind.   Quadrupeds, and even  the ape
tribe, have two bones  between the superior maxillary,
containing the dentes incisores when  these are  present,
and  termed ossa  intermaxillaria, incisoria, or  labialia.
Its universal existence in them, however, is not satisfac-
torily established.  Man alone has a prominent chin: his
lower jaw is the shortest, compared with the cranium;
and its condyles differ  in form, direction, and articula-
tion, from those of any animal:  in no animal  are  the
teeth arranged in such  a close and uniform series;  the
lower incisores, like  the jaw in which they are fixed, are
perpendicular,—a distinct characteristic of man, for in
animals they  slope backwards with the jaw bone;  the
canine are not longer than the rest, nor insulated, as  in
monkeys; the molares  differ from those of the ourang-
• Memoires de VAcademie des Sciences de Paris, 1764. 
390   CORPOREAL CHARACTERISTICS OF MAN.

.outang, and of all the genus simia, by their singularly ob-
tuse projections.
  The slight hairiness of the human skin in general, al-
though certain parts, as the pubis and axillae, are more
copiously furnished with hair than in animals; the situa-
tion of the  heart lying not upon the  sternum, as in qua-
drupeds, but  upon the diaphragm,  on account of our
erect position, the  basis turned not as in  them to the
spine, but  to the  head, and the apex to the left nipple;
the omnivorous structure of the alimentary canal; the
curve of the vagina corresponding with the curve of the
sacrum formerly mentioned, causing woman to be not,
as brute females are, retromingent; perhaps the hymen;
the singular structure of the human uterus and placenta;
the length of the umbilical chord, and the existence of the
vesicula  umbilicalis till the fourth month; the extreme
delicacy  of the cellular membrane; the absence of the
allantois, of the panniculus carnosus, of the rete mirabile
arteriosum, of the suspensorius oculi; and the smallness
of the foramen incisivum, which is not  only  very large
in animals, but generally double ;  are likewise structural
peculiarities of the human race.
  Man alone can live in almost every climate; he is the
slowest in arriving at maturity, and, in proportion to his
size, he lives the longest; he  alone  procreates at every
season, and, while in  celibacy,  experiences  nocturnal
emissions.   None but the human female menstruates.
  Man,  thus  distinguished  from  all other terrestrial
beings, evidently constitutes a  separate species,—fact
harmonizes with the Mosaic account of his distinct crea-
tion.  For " a species  comprehends all the individuals
a which descend from each other, as from a common pa-
" rent, nnd those which resemble them as much as they 
VARIETIES OF MANKIND.            391
 " do each  other," and no animal  bears such  a resem-
 blance to man.*
    He  is subject, however, to great variety, so great in-
 deed, that some writers have contended that several races
 of men must have been originally created.  We shall now
 examine the principal of these varieties.

                 The most  generally  approved division
, of mankind is that of Blumenbach.!  He makes five va-
 rieties;  the Caucasian,  Mongolian, Ethiopian, Ameri-
 can, and Malay.   The following are the characteristics
 of each.
    1. The Caucasian. The skin white; the cheeks red,
 —almost a peculiarity of this variety; the hair of a nut
 brown, running on the one hand into yellow, and on the
 other into black, soft, long, and undulating.
    The head extremely symmetrical, rather globular; the
 forehead moderately expanded; the cheek bones narrow,
 not prominent, directed downwards from the Malar pro-
 cess of the superior maxillary bone;  the alveolar edge-
 round ; the front teeth of each jaw placed perpendicularly.
    The face oval and pretty straight; its parts moderate-
 ly distinct; the nose narrow and slightly aquiline, or at
 least its dorsum rather prominent;  the mouth small; the
 lips, especially the  lower,  gently  turned out; the eh in
 full and round;—in short, the countenance of that style
 which we consider the most beautiful.
    This  comprehends  all Europeans, except  the Lap-
 landers, and the rest of the Finnish  race, the western
 * Cuvier. Discours Preliminaire aux reclierches sur les ossemens For-
tiles des Quadrupedes.
 i De generis humani vQrietate nativa. Sect iv. 
392
VARIETIES of mankind.
 Asiatics as far as the Obi, the Caspian, and the Ganges,
 and the people of the North of Africa.
   M. de Virey subdivides this variety into two parts :*
 the one with  very light skin and hair and  great muscu-
 lar strength, including most European nations, as  the
 Cimbri and Scandinavians,  Teutoni,  Celts, properly so
 called,  Goths, Saxons, Icelanders, Britons,  Normans,
 Francs, Italians, Greeks, and Celtiberians,  and even  the
 Galatae or Asiatic Gauls, who have spread themselves in%
 Asia  Minor, the Morea, Georgia, and  Circassia: the
 other not so  light, including the Vandals, Illyrians or
 Sclavonians, Getae, Sarmatae, Gepidae, Thracians,  Rus-
 sians, Turks, Tartars of the Crimea, Scythians, Persians,
 Arabians, Moors, and even  the Cisgangetic Hindus.
  2. The Mongolian. The skin of an olive colour; the
 hair black, stiff, straight and sparing.
  The head almost square ;  the cheek bones  prominent
 outwards;  the space  between the eyebrows, together
 with the bones of the nose, placed nearly in the  same
horizontal plane with the malar bones ; the superciliary
arches scarcely perceptible; the osseous nostrils narrow;
the fossa maxillaris shallow; the alveolar  edge arched
obtusely forwards; the chin somewhat projecting.
  The face broad and flattened, and its parts consequent-
ly less distinct; the  space between the eyebrows  very
broad as well as flat; the cheeks not only projecting out-
 wards, but nearly globular;  the aperture of the eye-lids
narrow, linear; the nose small and flat.
  This comprehends the remaining Asiatics, except the
 Malays of the extremity of the Transgangetic peninsula;
the Finnish races of the North of Europe,—Laplanders,
* Histoire JWitxtrelle du genre humain, Tom. 1. Sect. i. 
varieties of  mankind.
393
 &c.; and the Esquimaux diffused over the most northern
 parts of America,  from Bhering's Strait to the farthest
 habitable spot of Greenland.
   In this  M. de Virey makes three  subdivisions :  the
 first short, weak, barbarous and cowardly, and lean  and
 brown even in cold and temperate climates, embracing all
 the circumference of the Arctic pole, Spitzberg, Petzora
 and Greenland, the  Esquimaux, Tschutches,  Kamtschat-
 kans, Koriaks, Ostiaks, Gakats, Jukagres, Samoides,  and
 Laplanders : the second, for the most part horridly ugly,
 embracing the Eluths andCalmucks, Tunguses, Baskirks,
 true Cossacks, Kirghises, Tschouvachs, Burats, Soonga-
 rees, the Mantchoos people of the north of  China,  and
 the Tanjutic tribes of Thibet:  the third,  less ugly,  en-
joying  a more southern climate and fixed abodes, em-
 bracing the Chinese, Japanese, Coresians, Tonguinese,
 Cochinchinese, the people of Jesso, many of Thibet, the
 Siamese, 8cc.
   3.  Ethiopian.  The skin black ; the  hair black and
crisp.
   The head narrow, compressed laterally; the forehead
arched; the malar bones projecting forwards;  the osseous
nares large ;  the malar fossa behind the infra-orbitar fo-
ramen deep; the jaws lengthened forwards ; the alveolar
edge narrow, elongated, more elliptical;  the  upper front
teeth  obliquely prominent ; the lower jaw large and
strong; the cranium usually thick and heavy.
  The face narrow,  and projecting at its lower part;  the
eves prominent; the  nose thick and confused with the
projecting cheeks;  the lips, especially the upper, thick ;
the chin somewhat receding.
  The legs in many instances bowed.
  This comprehends the inhabitants of Africa, with  the
                        F, 3 
394
varieties of  mankind.
exception of those in the northern parts, already included
in the Caucasian  variety.
   M. de Virey here  also makes two subdivisions ; the
one embracing the people of the equatorial parts of Afri-
ca, of Nigritia and Guinea, the  Madingos, Jaloffs, Caf-
fres, Galla, the inhabitants of Conjo,  Angola, the coast
of Zanguebar,  Monoemugi, the interior of Madagascar
and of New Guinea, and lastly, the Papoos : the other of
an olive tint, nearly approaching to black, embracing the
Hottentots,  the Namaguese, nearly the whole of New
Holland and some neighbouring islands, as New Caledo-
nia and the island of the Quirds.*
  4. The American. The  skin of a copper colour; the
hair black, stiff, straight and sparing.
  The forehead short; the cheek bones broad, but more
arched and rounded than in the  Mongolian variety, not,
as in it, angular and projecting outwards;  the orbits ge-
nerally deep; the  forehead and vertex frequently deform-
ed by art; the cranium usually light.
  The face broad, with prominent cheeks,  not flattened,
but with every part distinctly marked, if viewed in pro-
file ; the eyes deep;  the nose rather flat, but still promi-
nent.
  This comprehends  all the Americans,  excepting the
Esquimaux.
  5. The Malay. The skin tawny; the hair black, soft,
curled, thick, and abundant.
  The head rather narrow; the forehead slightly arched;
the parietal bones prominent;  the  cheek bones not pro-
minent;  the upper jaw rather projecting.
  * The inhabitants of these islands are not included by Blumenbach
in the Ethiopian, but in the Malay variety. 
VARIETIES of  mankind.
395
   The face prominent at its lower part; not so narrow as
in the Ethiopian variety, but the features, viewed in pro-
file, more distinct;  the  nose full, broad,  bottled at  its
point; the mouth large.
   This comprehends the inhabitants of the Pacific,  Ma-
rian, Philippine, Molucca, and Sanda isles,  and of the
peninsula of Malacca.
   General Remarks.  The colour of the hair thus appears
somewhat connected with that of the skin, and the colour
of the iris is  closely connected with that of  the  hair.
Light hair is common  with  a  white and thin skin only,
and  a dark thick skin  is usually accompanied by black
hair; if the skin happens to  be variegated, the  hair also
is variegated ;  with  the milk  white skin of the albino, we
find hair of a  peculiar yellowish white tint;  and where
the skin is marked by reddish freckles, the hair is red.
When the hair is light,  the  iris is  usually blue ;  when
dark, it is of a brownish black; if the hair loses the light
shade of infancy, the iris likewise grows darker, and when
the hair turns grey, in advanced life, the iris  loses much
of its former colour ; the  albino has no more colouring
matter in his iris than in his  skin, and it therefore allows
the redness of its blood to appear; those animals  only,
whose skin is subject to varieties, vary in the  colour of
the iris;  and if the hair and skin happen to be  variegated,
the iris is observed likewise variegated.*
  • The hair is frequently of different shades in different parts.  John
Hunter remarked, that the iris in animals agrees  principally with the
colour of the eyelashes.  However various the colour of the hair in
horses, the iris, he also observes, is always of the same.  But then the
hair is always of the same at birth, and the skin does not participate in
its subsequent changes, being as dark in white as in black horses.  In
cream-coloured horses, indeed, there is an exception, the iris agrees 
396
varieties  of mankind.
   The  Caucasian variety of  head, nearly round,  ib the
mean of the rest, while the  Mongolian,  almost square,
forms one extreme, having the American intermediate ;
and the Ethiopian the other extreme, having the Malay
intermediate between it and the Caucasian. .
   The  Caucasian variety of  face is also the mean, while
the Mongolian and American, extended  laterally,  form
one extreme,  and  the  Ethiopian and Malay, extended
inferiorly, constitute the other.  In the first of each ex-
treme,  viz.  the Mongolian and Ethiopian, the features
are distinct, while in the second, viz. the American and
Malay, they are confused.
   Although this division of mankind is well founded and
extremely useful, it is liable,  like every artificial division
of natural objects,  to many exceptions.   Individuals be-
longing to one variety  are  not unfrequently observed
with some of the characteristics of another ;*  the charac-
with the hair, but then the foals are originally cream coloured, and the
skin is cream coloured.  Hunter, Ont/ie colour of the pigmentum of the
eye in different animals.  Obs. 247.
  * " Sooty blackness is not peculiar to the Ethiopian, but is occasion-
" ally found in other varieties of men very different and remote from
"each other, in the Brazilians, Californians, Indians, and some South
" Sea Islanders ; and among the latter, the new Caledonians form an in-
" sensible transition with the chesnut coloured inhabitants of Tongata-
" bu, from the tawny Otaheitans to the black New Hollanders. Blumen-
"bach, De generis humani varietate nativa. Sect. 43.
  " Some tribes of Ethiopians have long hair (Bruce on the Galla;
"African Institution on  the people of Bornan;) on the contrary, some
" copper coloured people have the crisp hair of the Ethiopian.  (The
" inhabitants of the Duke of York's island, near new Ireland ; Vide
" Hunter's Historical Account of the  Proceedings at Port Jackson ,-J
" again, the hair of the New Hollanders, specimens of which I have
" now before me, is so perfectly intermediate between the crisp hair of 
VARIETIES  OF  MANKIND.
397
teristics of two  varieties are often intimately blended in
the same individual (indeed all the  four varieties run
" the Ethiopian and the curly hair of the islanders of the Pacific ocean,
*' that there has been much diversity of opinion, from the first Dutch
" to the latest English travellers, to which of the two varieties it should
" be referred.  As to the varieties of  colour existing among nations
" whose hair is usually black, we have sufficient authority for asserting,
" that numerous instances of red hair  occur in all the three last vari-
" cties."   1. c. sect. 52.
  " The Caffres and the people of Congo have hair not unlike that of
" Europeans.  Even the Foulahs, one  of the Negro tribes of Guinea,
"have, according to Mr.  Park, soft, silky hair; on the other hand, the
" inhabitants of many  other countries resemble the Africans in their
" hair, as the savages of New Guinea, Van Diemen's land, and Malli-
" collo.  And in the same island, some of the people are found with
"crisp and woolly, others with straight hair,  as in the New Hebrides.
"In New Holland, there are tribes of each character, though resem-
" bling in other particulars."   Pricliard's Researches into the Physical
History of Man.  p. 83.
  " Many tribes of the Negro race approach very near to the form of
" Europeans.  The Jalofts of Guinea,  according to Park, are all very
" black; but they have not the characteristic features of the Negro—
" the  flat nose and thick lips : and Dampier assures us that the natives
" of Natal in Africa have very good limbs, are  oval visaged, that their
" noses are neither flat nor high, but very well proportioned; their teeth
" are  white, and  their aspect altogether graceful.  The same Author
" (Dampier's Voyages J informs us, that their skin is black, and their
" hair crisped.  Nor are others of this diversity more constant.  In the
" native race of Americans, some tribes are found, who differ not in the
"characters in question from Europeans. Under the 54° 10'of north la-
" titude," says Humboldt," at Cloak-bay» in the midst of copper-colour
"ed Indians, with small long eyes, there is a tribe with large eyes, Eu-
" ropean features, and a skin less dark than  that  of our peasantry."
Humboldt's Essay on JWw Spain, translated. 1. c. p. 62.  note b.
   " The features of the inhabitants of the Friendly Islands are very
" various, insomuch that it is scarceh possible to fix on any general 
398
VARIETIES OF MANKIN».
 into  each other by insensible degrees ;)* and" instances
 continually occur of deviation in one or more particulars
 from the appearances characteristic of any variety;] so
 that the assemblage, rather than individual marks, must
 frequently be employed to determine the variety.
   Particular Remarks.   The Caucasian variety is pre-
 eminent  in  all  those mental and corporeal particulars
 which distinguish man from animals. The general aspect
 is dignified; the men appear formed for valour and con-
 templation,  the women for every sweet attractive grace.
 The cranium is very capacious; the area of the face bears
 to its area but a proportion of one to four, and projects
 little or not at all at the lower parts : the intellectual fa-
 culties are susceptible of the  highest cultivation.  Philo-
 sophy and the fine  arts flourish in it as in their proper
'soil: to it revelation was directly granted.
   The Ethiopian variety, when instructed by the Cauca-
 sian, has produced  instances of mental advancement great
" likeness by which to characterise them, unless it be a fulness at the
" point of the nose, which is very common.  But, on the other hand,
" we met with hundreds of truly European faces, and many genuine
"Roman noses among them."
  "Similar examples," remarks Blumenbach  on this passage, (Cook's
last voyage.  Vol. 1. 382. 1. c.  § 55.  note.)  " are observed,  among
" Ethiopian and American nations ; and, vice versa, the resemblance
" of individual  Europeans to Ethiopians  and Mongoles is very fre*
" quent, and has become even proverbial."
  • " The Tartars of the  Caucasian variety  pass, by means  of the
" Kirghises and neighbouring people,  into the Mongoles, in the same
" manner as these, by means of the people of Thibet, into the Indians,
" by means of the Esquimaux, into the Americans, and, by means of
" the Philippine Islanders, even in some measure into the Malays."
Blumenbach. 1. c. § 86.
  t See note, page 396. 
VARIETIES OF MANKIND.
39v>
 indeed, but inferior  to  what the latter is capable of at-
 taining.  u There scarcely  ever," says  Hume, " was a
  civilized nation of that complexion, nor even an indi-
 " vidual, eminent either in action or speculation.   No
 ' ingenious  manufactures amongst   them, no arts, no
 " sciences.   On the  other hand, the most rude and bar-
 " barous of the whites, such as the ancient Germans, the
 "present Tartars, have  still something eminent about
 " them,  in their valour,  form of government, or some
 " other particular."*  Blumenbach, however, possesses
 English, Dutch  and Latin poetry,  written by different
 negroes, and informs us, that, among other examples of
 distinguished negroes, a native of Guinea, eminent for
 his integrity, talents, and learning,  took the degree of
 doctor in philosophy, at the University of Wittenberg;'
 and that Lislet, of the Isle of France, was chosen a cor-
 responding member  of the French Academy of Sciences.
 " Provinces of Europe," says he, " might be named, in
 " which  it would be no  easy matter to discover such
 " good  writers, poets, philosophers,  and correspondents
 " of the French Academy; and on the other hand, there
 " is no savage people which have distinguished them-
 " selves by such examples of perfectibility, and even ca-
 " pacity for scientific cultivation, and, consequently, that
 " none can approach more nearly than the negro to  the
 "• polished  nations of the globe."f This mental inferiority
 is attended of course by  a  corresponding  inferiority of
 the brain.   The circumference, diameters, and vertical
 arch of the cranium being smaller than in the Eui-opean,i;

  * Hume's Essays, Part 1. Essay 21. Note M.
 f Beytriige zur Naturgeschichte. p. 118. Vide Rees's Cyclopaedia.
 t Soemmcrring.  De basi cranii et originibus nervorum cranio egre-
d>entivn. 
400
VARIETIES OF MANKIND.
and the forehead particularly being narrower and falling
back in a  more arched  form, the brain in general, and
particularly those parts which are the organs of intellect
properly so called,* must be of inferior size. The orbits
on the  contrary, and the olfactory  and gustatory, or ra-
ther masticatory organs, being more amply evolved, the
area of the face  bears a greater proportion  to the area of
the skull,—as 1. 2. to 4.;  the proportion is greater in the
ourang-outang, and in the carnivora nearly equal.f The
senses  here situated, as well as that of hearing,  are re-
markably  acute, and the corresponding  nerves,  at least
the first, fifth, and facial, of great size4       *-
   The  ossa nasi lie so  flatly  as to form  scarcely  any
ridge;  the  face, as we have formerly seen,  projects con-
siderably at its lower part;§ the lower  jaw is not only
long, but extremely strong; the chin not only not promi-
  * Spurzheim's Physiognomical system.
  ] Cuvier's Logons d''Anatomic Comparee.
  $ Soemmerring.
  § Camper. (Dissertation physique sur les differences reelles, que pre-
sentent les traits du visage  chez les hommes de diffirens pays et de dif-
fe"rens ages J gives the following proportions of the facial angle.
       European.......80 or 90
       Chinese........75
       Negro    ..-.-.--70
       Ourang-outang.....-    42
  Mr. White (Essay on the regular gradation,J states  them rather
differently.
       Monkey........40 to 50
       Oui-ang-outang......50   60
       African........60   70
       American      -    -.....70   75
       Asiatic   -        ......75   80
       European              -                     80   90 
VARIETIES OF MANKIND.
401
nent, but even receding, and the space between it and
the lower teeth is  small, while that between the upper
teeth and the  nose is  large; the meatus auditorius  is
nearer the  occiput,—more remote from the front  teeth
than in the  European;  the foramen magnum  occipitale
lying farther back, the occiput is  nearly in a line with
the spine ; the body is slender, especially in the loins and
pelvis, whose cavity likewise is small; the length of the
fore-arms and fingers bears a large proportion to that  of
the os humeri;  the os femoris and  tibia are more con-
vex, and the edge of the latter, which, in consequence  of
hearing the  remark from my  friend  Mr. Fyfe, of Edin-
burgh, I have frequently examined in living negroes, is
very sharp ; the calves are placed high; the os calcis, in-
stead of forming an arch, is on a  line with  the other
bones of the foot, which is of great breadth; the toes are
long; the penis large, and frequently destitute of frsenum.
   Mr. White, from whom many of these remarks are
derived, describes the testes  and scrotum as small, but
this does not accord with my own experience; the skin
is thicker;* and finally the term of  life shorter, than  in
Europeans.
   Nearly all these facts demonstrate a greater  affinity  of
the Negro than of  the European to the brute creation.
But so slightly  inferior to the Caucasians, and so im-
mensely  superior to the most intelligent  animals, the
poor negro might justly class those of us, who philosophi-
cally  view him  as merely  a better kind of monkey,  or
  • The  temperature of the Negro is said to be two degrees cooler
than  that of Europeans ; and the voluptuous, therefore, to prefer a
Negress  in  summer, a fair Circassian  in spring and autumn, and an
European brunette in winter.
                          F 3 
402
VARIETIES OF MANKIND.
who desire to traffic in his blood, not only below himself,
but below apes in intellect, and tigers in feeling and pro-
pensity.
        " Indica tigris agit rabida cum tigride pacem
        " Perpetuam. Ssvis inter se convenit ursis."*
  The Malays  have but little hair upon the chin, and
possessing a great developement of the parts of the head
above the ears,  are,  as might be  expected,! signalized
for their treachery, cunning, and ferocity, and their pas-
sionate fondness for poetry.
  The Mongolians are remarkably square and robust;
their shoulders high; their extremities short and thick.
  The Americans  have small hands and feet, and are
nearly destitute  of  beard.  Shorter in the forehead  than
the Mongolians, they have not so great intellectual dis-
tinction.
  Not only have the five varieties their distinctive cha-
racteristics, but the different nations comprehended in
each  variety, have  each their peculiarities, both mental
and corporeal: among the Caucasians, for example, the
Germans, French,  Spaniards and English, are extreme-
ly different from each other.   Nay, the  provinces of the
same country differ,  and the families of the same  pro-
vince, and, in fact, every  individual has his own pecu-
liar countenance, figure, constitution, form of body, and
mental character.
* Juvenal. Sat. L. xv. 163.
f Spurzheim's Physiognomical System 
VARIETIES OF MANKIND.
403
   A qjjestion here presents itself.—Are the differences
 among mankind to be  ascribed to the influence of va-
 rious causes upon the descendants  of two;—or of more,
 but  all similar, primary parents ;—or to original differ-
 ences in more than  two primary parents ?  If considera-
 tions a priori, analogical and direct facts, and the history
 of mankind,  corroborate in conjunction the first supposi-
 tion, there will be  no necessity to have  recourse to the
 bolder second, nor to the third,—the boldest of the three.
   Our inquiries on this point should be prosecuted, as
 well as all inquiries into nature, without reference to re-
 velation.   Lord Bacon has observed, that the  union of
 religious  and philosophical  investigation is often detri-
 mental to the cause of truth.*
   If we resolve to  make religion and philosophy harmor
 nize before we are  certain of being perfectly  acquainted
 with the meaning of the sacred text, or masters of all the
 facts necessary to establish legitimately  a philosophical
 opinion, the one or the other, or  perhaps both, will be
 strained and distorted.  The truth will be more readily
obtained, if we examine the  sense of scripture, indifferent
to the conclusions  of philosophy,  and inquire  into  na-
ture, indifferent to the pronunciations of  revelation.
They must ultimately  agree; for the works and the voice
of the Almighty cannot  contradict  each other.   But this
agreement should be spontaneous ; assured that it  will
ultimately occur, its  absence  should have  no  other in-
fluence upon our minds, than to  stimulate us to farther
inquiry, convincing us that either our conclusions  are
illegitimate,  or  our facts deficient; but not inclining us
to deviate in the least  from  the severest and most inde-
* Cogitata et visa. 
404
VARIETIES OF  MANKIND.
pendent mode of investigation, nor to force the scriptm t.
from its well established signification.
   On the point before us, the Bible speaks positively and
clearly, without the possibility of various interpretation or
corruption of the text, and not only in the account of the
creation, but incidentally in  many other places.*  It is
  * The writer of the article Man, in Rees's Encyclopxdia, remarks,
that the book of Genesis does  not clearly assert that Adam and Eve
were the parents of mankind.   If we read the whole Bible, we shall
find our descent  from Adam and Eve frequently alluded to, both in
the Old and New Testament,  and not merely as an indifferent fact,
but as one of the fundamental truths of revelation; and thus any sup-
posed obscurity in the book of Genesis completely dispelled. His ob-
ject, however,  seems not to charge Moses with obscurity, but with
contradiction.  He says,—' We are told, indeed, that " Adam called his
" wife's name Eve, because she was the mother of all living."  But in
' the first chapter of Genesis we learn, that  God created man, male
' and female, and this seems to have been previously to the formation
' of Eve, which did not take place till after the garden of Eden had
c been made. Again, we are informed,  in the fifth chapter of Genesis,
' that " in the day God created man, in the likeness of God, created
" he him ; male and female, created he them ; and blessed them and
" called their name Adam, in the day when they were created.'" Now
the second chapter of Genesis is a recapitulation,  and, at the same
time, a more circumstantial detail of what  is contained in the first.
In the  first, the man and woman are said to have been created on the
sixth day;  in  the second,  we are further informed how and in what
order each was formed,—that the man was formed  of the dust of the
earth,  and  placed in the garden of Eden, (planted, it appears from
perusing the whole of the second chapter, before his creation, no less
than before that of Eve)  where he  fell into a deep sleep, during
which the woman was formed from a part of his  body.  Is this ob-
scure or contradictory ?
   ' We find also that Cain,' continues this writer, (in the words of
 Mr. White, of Manchester) ' after slaying his brother, was married,
 ' although it does not appear that Eve had produced any daughters 
                 VARIETIES  OF MANKIND.             405
                                                   »'

delightful to find nature and history investigated already
so far, as to harmonize with the  statement of holy writ:
•before this time.'  "Cain went out from the presence of the Lord,
" and dwelt in the land of Nod, on the east of Eden.  And Cain knew
"his  wife, and she conceived and bare Enoch."  Indeed, it is  said,
(ch. 5. v. 4.) that  " the days of Adam,  after he had begotten Seth,
" were eight hundred years, and he begat sons and daughters." ' This,
' it should seem, took place after the birth of Seth, and consequently,
' long after Cain had his wife ;  for Seth was not born till  after the
• death of Abel.  If Cain had sisters prior to that period, from amongst
' whom he might have taken a wife, it is singular, as some persons
* may allege, that Moses should not have noticed them.'  By no means
singular.  Moses relates a few most important  circumstances  only,
just sufficient to carry on the history from the creation;  the first six
chapters comprehend a period of no  less  than  sixteen hundred and
fifty-six years.   Although the marriages of Adam's descendants are
continually alluded to, yet, as the successions and periods of the births
of the men only were important to his history, he does not,  I believe,
individually mention, during the first nineteen  hundred and fifty years
of his history, the daughter of any particular person.  His silence, ::»
this particular,  is conspicuously seen in the fifth chapter; for exam-
ple, where, after mentioning the birth of the first son, and the amount
of the subsequent years of the father's life,  he  merely adds,  " and be-
gat sons and daughters ;" not only in regard to Adam, but to his de-
scendants.  He passes over in silence even individual sons, when they
constitute  no link,  and  are  connected with no remarkable circum-
stance, in his history of our race.
  I, as a  believer in the divine origin of Christianity, and, I trust,
from  rational conviction, earnestly entreat this writer, and all others,
who  are inclined to despise the Scriptures, to distinguish between
Christianity and  sanctified cant, and  to suspend their unbelief and
sarcasms, till they have dispassionately studied at least the four gos-
pels,  and the works of Bishops Butler and Watson, of Paley,  Dr. Malt-
by, and Mr. Leslie.
  • Hume  owned to a clergyman, in  the bishopric of Durham, that he
' had  never read the New Testament with attention.'!       .
       ] (Boswell's Life of Johnson, Vol. ii. p.  7- fifth edition.) 
 406            VARIETIES  OF MANKIND.

 but we shall detail the arguments, independently of this
 consideration.*
   A priori, I think, the universal simplicity of nature's
 causes would  induce us to  imagine, that as, if the vari-
eties among us are accidental, two individuals were evi-
 dently sufficient for the production  of the  rest of  man-
 kind, no more than two were originally created.   Nor
 can I conceive it possible to deduce a contrary presump-
 tive argument, from the length of time during which im-
 mense portions of the earth  must  have thus remained
 unpeopled.   One of nature's objects seems the existence
 of as much life as possible, whether animal or vegetable,
 throughout the globe.   For this purpose, every species
 of animal and vegetable possesses an unlimited power of
 propagation, capable of filling the whole  world, were op-
 portunity afforded it.  The  opportunities of exertion are
 indeed very scanty,  compared with the  power;  one ve-
 getable, one animal, stands in the way of another;  even
 the impediments to  the increase of some, act through
them as impediments to others.   The  constant tendency
 of the power of multiplication to exert itself seizes every
opportunity the moment it is presented,  and thus nature
  * All the animals of each species appear descended from one stock,
for the animals of the two hemispheres are all of distinct species, ex-
cepting in the northern regions, where a communication is very expli-
cable.  The same is true of the  animals of the arctic and antarctic
regions : prevented, like the more equatorial animals of the two he-
mispheres, by the intermediate climate, from communicating with
each other, they are all of distinct species.  In islands remote from
continents, either no quadrupeds are found, or such as have been con-
veyed thither, or such as are different from  any others ;  while in isl-
ands  near continents, the quadrupeds are the same as  in the neigh-
bouring country. 
VARIETIES  OF MANKIND.
407
 constantly teems with life.   The slow increase of man-
 kind could not interfere with this apparent object of na-
 ture ; the deficiency of our race must have invariably
 been fully compensated by  the opportunities which it
 afforded for the multiplication of other existences: for
 that man alone was not designed to fill the  earth is shown
 by the vast tracts of land still but thinly peopled.   The
 infinitely rare opportunities afforded for the maturity of
 the intellectual and moral powers, born with every human
 being, may afford still greater surprise than the extent of
 country  unoccupied by man.   After all,  the originally
 great length of  life must  have contributed so much to
 man's multiplication, that were food sufficiently supplied,
 he might very speedily have  covered the earth.
   Analogical and direct facts lead us  to  conclude, that
 none of the differences among mankind are so great as to
 require the belief of their originality.
  Animated beings  have a general tendency to produce
 offspring resembling themselves, in both mental and cor
 poreal qualities.

          " Fortes creantur fortibus et bonis ;
          " Est in juvencis, est in equis patrum
          " Virtus : nee imbellem feroces
          " Progenerant aquilse columbam."*

  An exception occasionally occurs, much more frequent-
ly indeed in the domestic than the wild state,—the off-
spring differs in some particular from the parents ; and,
by the force of the general tendency, transmits to its off-
spring its own peculiarity.  By selecting such examples,
a breed peculiar in colour, figure, the form of some one
• Horace, L. iv. od. 4. 
408           VARIETIES OF MANKIND*
part, or in some mental quality, may be produced. Thui>,
by killing all the black individuals which appear among
our sheep, and breeding only from the white, our flocks
are white; while, by an opposite practice, pursued in
some countries, they are black : thus a ram, accidentally
produced on a farm in Connecticut, with  elbow-shaped
fore-legs, and a great shortness and weakness of joint
indeed in all four  extremities, was selected for propaga-
tion, and the «v*«» breed, unable to climb over fences, is
now established :* thus some breeds of hares have horns
like the roebuck : the Dorking fowl has two hind claws ;
and fowls indeed are bred in every conceivable variety.f
Individuals,  distinguished from others by no greater dif-
ferences than  those which thus  spring  up accidentally,
cannot be supposed to belong to a separate species. Upon
the comparison of these differences depends the analogi-
cal argument first employed by Blumenbach.   Finding
the ferret (mustela furoj  to  differ from  the pole cat
(putorius) by the redness of its eyes, he concludes it is
merely a variety of  the same species,  because instances
of this deviation are  known to occur accidentally  in other
animals;  but he concludes the African elephant is of a
  * Thomson's Annals of Philosophy, No. 2.
  ] The offspring most frequently resembles both parents, but the
proportion of resemblance to each is extremely various, some children
favouring the father most,  some the mother, though  all sufficiently
resembling each to preserve a family likeness; some stamped by any-
accidental singularity of one parent, others not; and it is remarkable,
that the resemblance to the parents,  whether  in  regard to usual or
singular peculiarity, is occasionally not observed in the  immediate
offspring, but reappears in the third, or even some later generation 
VARIETIES  OF MANKIND.
409
 species distinct from the Asiatic, because the invariable
 difference of their molar teeth is of  a description which
 naturalists have never found accidental.  Now there ex-
 ist among mankind no differences greater than what hap-
 pen occasionally in individual species of animals.
   The colours of the animals around us, horses, cows,
 dogs, cats,  rabbits, fowls, are extremely various, black,
 white, brown, grey, variegated.
   The hair of the wild Siberian sheep is close in sum-
 mer,  but rough and curled in winter ;* sheep in Thibet
 are covered with the finest wool, in Ethiopia with coarse
 stiff hair ;f the  bristles of the hog in Normandy are too
 soft for the manufacture of brushes;] goats, rabbits, and
 cats of Angouri,  in Anatolia, have very long  hair,  as
 white as snow and as soft as silk.§
   The head of the domestic pig differs as much from that
 of the wild animal, as the Negro from the  European  in
 this  respect ;|| so the head of the Neapolitan horse, deno-
 minated ram's head, on account of its shape, from that of
 the Hungarian animal, remarkable for its shortness and
 the extent of its lower jaw ;** the cranium of fowls at
 Padua is dilated like a shell,  and perforated by an im-
 mense number of small holes ;ff cattle and sheep, in some
parts of our own country, have horns, in others not;  in
Sicily, sheep have enormous horns :]]  and in some in-
  * Pallas.  Spicileg. Zoologica.       ] Blumenbach. 1. c. § 28.
  M. c.          § 1. c.          || 1. c.          **  1. c.
  j-j- Pallas.  Spic. Zool. fasc. iv. p. 22. Sandifort. Museum Anattmi-
cum acad.  Lugd. Batav. T. 1. p. 306.
  *\ Blumenbach. 1. c. § 30.
                         G .1 
410
VARIETIES OF MANKIND.
stances, this animal has so many, as to have acquired the
epithet polyceratous.
  The form of other parts is no less various.  In  Nor-
mandy, pigs have hind legs much longer than the fore ;*
at the Cape of Good Hope, cows have much shorter legs
than in England ;f the difference between the Arabian,
Syrian, and German horses  is  sufficiently known; the
hoofs of the pig may be undivided, bisulcous, or trisul-
cous.
  These are regarded by naturalists as but accidental
varieties; yet they equal or surpass the varieties existing
among mankind.  We are consequently led by analogy
to conclude, that the differences of nations are not origi-
nal, but acquired;  and  impose no necessity for believing
that more than one stock was at first created.
  Direct facts harmonize with this conclusion. All races
run insensibly one  into another, and therefore innumera-
ble intermediate examples occur, where the distinction
between two varieties  is lost.  Again,  no peculiarity
exists in any variety, which does not show  itself  occa-
sionally in another; many instances of these facts have
been related in the notes to page 396.  The difficulty of re-
garding the negro as of the  same stock with  ourselves
vanishes, on viewing these circumstances, and on reflect-
ing that he and ourselves are two extremes, one of which
may have sprung from the other, by means of  several
intermediate deviations, although experience may not
justify the belief, that  any single deviation could be of
sufficient magnitude.   An instance, however, is related,
in the Philosophical Transactions,  of a  black  family,
which lived where  Europeans had never approached, and
* Blumenbach, 1. c. § 30.
fl.c 
                VARIETIES OF MANKIND.            411

from time to time produced a white child.*   Lastly, all
the varieties breed together readily and  in  perpetuity,|
—an assertion which  cannot be made in regard to any
different species of animals.
   The  cause of the differences of  our species  has been
more or less sought for in climate,  alone, or in  conjunc-
tion with other external circumstances, by Aristotle, Hip-
pocrates, Cicero,  Pliny,  Plutarch, Galen, nearly all the
Greek  and  Roman historians,  and  poets,  Montaigne,
Montesquieu, Buffon, Zimmerman,  Blumenbach,  Dr.
Smith,  of America, &c.  Lord Kaimes has denied the
power of these circumstances to produce the diversities
of either mind or body; and Hume  has expressly written
an essay, to prove  the  insufficiency of climate with re-
spect to the varieties of national character.  Now the in-
tensity  of light  unquestionably  affects the colour of the
surface, although not to the degree of Ethiopian black-
ness; heat the texture and growth of the hair; and quan-
tity of nourishment the size. But the effects of these cir-
  * Two blacks, marrying, produced a white child; the woman, fear-
ing her husband's  resentment, endeavoured to conceal it from him.
The man, however, insisted upon seeing the  infant, and finding it
white, said,  * I love it the better for that; for my own father was a
« white man, though my grandfather and grandmother were as black
'as you and myself; and although we  come from a place where no
«white people were ever seen, yet there was always a white child in
•every family that was related to us.' Phil. Trans. Vol. 55.
  An instance  is likewise very credibly stated of an adult negress,
who, from no evident cause, grew white, and, in the course of fifteen
years,  became scarcely inferior in any part of her surface to an Euro-
pean.  Phil.  Trp,ns. Vol. 51.
  f An instance has already been mentioned of what is a still strong-
er argument,—the simultaneous production of two individuals of dif-
ferent varieties by the same mother 
412
VARIETIES OF MANKIND.
cumstances are superficial, even on animals  necessarily
less  protected  against  their influence than man.  The
skulls of foxes belonging to northern regions are not dif-
ferent from those of  France or Egypt: the tusks of the
elephant, and the horns of the stag and rein deer, may
acquire  a larger size when the food is more favourable
to the production of ivory or horn, but the number and
articulations of the bones, and the structure of the teeth,
remain  unaltered.*  Nor are these changes any  more
than those  induced by mechanical means, as pressure,
division, &c. transmitted to the offspring: the child of
the most sunburnt  rustic is born equally fair with other
children; even all the children among the  Moors are
born white, and acquire the brown cast of their  fathers
only if  exposed  to the sun ;| although the Jews have
most religiously  practised the rite of circumcision from
the days of Abraham,  their foreskin  still  remains to be
circumcised. Were it therefore true that all dark  nations
are the  inhabitants  of hot climates, as the confined know-
ledge of the ancients justified them in  believing, it would
still be  untrue that the change effected, for instance, in
the colour of the parent's skin, had descended to  the off-
spring.   But modern discovery has made  us acquainted
with light nations,  inhabiting the warmest regions, with
dark nations inhabiting the coldest,  and  with others of
various shades of colour, although in the same climate.:):
  * Cuvier. Discours Priliminaire aux Rtcherches sur les Ossemens
Fossiles des Quadrupedes. Natural varieties only are meant.  Local
situation can produce the most intimate structural diseases,- witness
Cretinism.
  ] Poiret's Voyage en Barbaric T. i. p. 31. Vide Blumenbach, 1. c.
  t Lord Kaimes, M. de Virey, and Dr. Prichard, have quoted many , 
VARIETIES OF MANKIND.
413
Nor are the varieties  of mankind  more connected with
the  varieties of food.   In the present state of our know-
ledge, it is impossible fully to account for them.
instances of these facts.   • We found,' says Humboldt, * the people of
' the Rio Negro swarthier than those of the lower  Orinoco, and yet
' the banks of the first of these  rivers enjoy a much cooler climate
' than the more northern regions. In the forests of Guiana, especially
'near the sources of the  Orinoco, are  several tribes of a whitish com-
' plexion, the Guiacas, Guajaribs, and Arigues, of whom several ro'-
' bust individuals, exhibiting  no  symptom of the asthenical malady
* which characterizes Albinos, have the appearance  of true Mestizos
' Yet these  tribes have never mingled with Europeans, and are sur-
' rounded with other tribes of a dark  brown hue.  The Indians, in the
'torrid zone, who inhabit the most elevated plains of the Cordilleras,
' of the Andes, and those who, under the 45° of south latitude, have as
' coppery a complexion as those who, under a burning climate, culti-
* vate bananos in the narrowest and deepest vallies of the Equinoctial
' region. We must add, that the Indians  of the mountains are cloth-
' ed, and were so  long  before the conquest; while the Aborigines,
* who wander over the plains, go quite naked, and are consequently
* always exposed to  the perpendicular rays of the sun.  1 could never
»observe that in the same individuals those parts of the body  which
* were covered were less  dark than those in contact with a warm and
' humid air.  We every  where perceive that the colour of the Amcri-
* can depends very  little on  the local position in which we see him
 * The Mexicans, as  we have already observed, are more swarthy than
 ' the Indians  of Quito and New Granada, who inhabit a climate com-
' pletely analogous, and we even see  that the tribes dispersed to the
• north of the Kio Gila are less brown than those  in the neighbour-
' hood of the kingdom of Guatimala.   This deep colour  continues to
 • the coast nearest to Asia ; but under the  54° 10' of north latitude, at
' Cloak bay, in the midst of copper coloured Indians, with small long
 'eyes,  there is a tribe with  large eyes, European  features, and skin
 ' less dark than that of our peasantry.' Political  Essay on JVev> Spain,
 translated.
   The Jews  settled in the neighbourhood of Cochin 'are divided in-
 ' to classes,  called  the Jerusalem or white Jews, and the ancient or 
+14
VARIETIES
OF MANKIND.
   Widi civilization and barbarism, however, they appear
intimately connected. We should beforehand be inclined
to suppose that the most excellent developement of every
animated  species would be effected where  all its wants
were best supplied, its powers all duly called  forth, and
all injurious or unpleasant circumstances least prevalent:
and vice versa.  But experience teaches us that no change
can by  any  means be  brought  about in  an individual,
and transmitted to the offspring: the causes  of change in
a species must therefore operate, not by altering the pa-
rents, but by disposing them to produce an offspring more
or less different from themselves. Such is Mr. Hunter's
'black Jews.'—' The white Jews look upon the  black Jews as an in-
* ferior  race, and not as a pure cast, which plainly demonstrates that
' they do not spring from a common stock in India.'
  The white appear to have resided there upwards of seventeen hun-
dred years. Buchanan's Christian Researches in Asia, 219, &c.
  Dr. Shaw and Mr. Bruce describe a race of fair people in  the
neighbourhood of Mount Aurasius, in Africa, who, * if not so fair as
' the English, are of a shade lighter than that of any inhabitants to
' the southward of Britain.  Their hair also was red, and  their eyes
' blue.'  They are imagined to be descendants of the Vandals. Bruce's
Travels.
  The  Samoiedes, Greenlanders,  Laplanders,  Esquimaux, &c.  are
very swarthy;  nay, some of the Greenlanders are said to be as black
as Africans.
  ' Do we not in fact behold,'  says the learned and eloquent  M. de
Virey, ' the tawny Hungarian dwelling for ages under the same pa-
' rallel, and in the same country with the  whitest nations of Europe;
• and the red Peruvian, the brown Malay, the nearly  white Abyssini-
' an, in the very zones  which the blackest people in the universe in-
' habit.  The natives of Van Diemen's land are black, while Europeans
 of the corresponding northern latitude are white, and the Malabars,
' in the most burning climate, are no browner than the Siberians. The
I 
VARIETIES OF MANKIND.
415
view of the  question,* and it is certainly  confirmed by
every fact.   Uncivilized nations exposed to the incle-
mency of the weather, supported by precarious and fre-
quently unwholesome food, and having none of the distin-
guishing energies of their nature called forth, are almost
universally dark coloured and ugly; while those who en-
joy the blessings of civilization, i.e. good food and cover-
ing, with  mental cultivation  and enjoyment, acquire in
the same proportion the Caucasian characteristics.   The
different  effects of different degrees of cultivation, says
Dr. Smith, ' are most  conspicuous in those countries in
* which the laws  have made  the most complete and per-
* manent division  of ranks. What an immense  difference
' exists in Scotland  between the  chiefs and the common-
4 alty of the highland clans.  If they  had been separately
' found in different countries, the  philosophy of  some
1 writers would have ranged them in different species.  A
1 Dutch, who have resided  more than two centuries at the Cape of
' Good Hope, have not acquired the sooty colour of the native Hotten
' tots ; the Guebres and Parsees, marrying only among themselves, re-
' main white in the midst of the olive coloured Hindus.' Histoire J\ra-
turelle du genre humain, par J. T. Virey. Tome premier, page 124.
  * " As animals are known to  produce young which are different
from themselves  in colour, form, and disposition, arising from what
may be called the unnatural mode of life, it shews this curious power
of accommodation in the animal economy, that, although  education
can produce no change in the colour, form, or disposition of the ani-
mal, yet it is capable of producing a principle, which becomes so na-
tural to the animal  that it shall beget young different in colour and
form ; and so altered in disposition, as to be more easily  trained up
to the offices in which they have been usually employed; and having
these dispositions suitable to such changes of form "  Hunter's Ob-
servations, tic. on the wolf, jackall, and dog. 
410
VARIETIES O* MANKIND.
 4 similar distinction takes place between the nobility and
 4 peasantry of France, Spain, of  Italy, of Germany.  It
 * is even  more conspicuous in eastern  nations, where a
 ' wider difference exists between the highest and the low-
 4 est classes in society. The naires or nobles of Calicut, in
 * the East Indies, have, with the usual ignorance and pre-
 4 cipitancy of travellers, been pronounced a different race
 ' from the populace; because the former, elevated by their
 ' rank, and devoted only to martial studies and achieve-
 * ments, are distinguished by that manly beauty  and ele-
 * vated stature, so frequently found with the profession of
 4 arms ; especially when united  with nobility of descent;
 ' the latter poor and laborious, and exposed to hardships,
 ' without the spirit or the hope  to better their condition,
 4 are much more  deformed and diminutive in their per-
 * sons, and in their complexion much more  black.  In
 4 France, says Buffon, you may distinguish by their aspect
 4 not only the nobility from  the peasantry, but the supe-
 ' rior orders of nobility from the inferior, these from citi-
 1 zens, and citizens  from peasants.'—The field  slaves in
 America, continues Dr. Smith, 4 are badly clothed, fed,
4 and  lodged, and live in small huts on the plantations,
 4 remote from the example and society of their superiors.
 4 Living by themselves, they retain many of the customs
 4 and manners of their ancestors. The domestic  servants,
 4 on the other hand, who are kept near the persons, or
 ' employed in the family of their masters, are treated with
 4 great lenity, their service  is  light,  they are fed and
 4 clothed like  their superiors,  they see their manners,
 ' adopt their habits, and insensibly receive the same ideas
 4 of elegance and  beauty. The  field slaves are in conse-
 4 quence slow in changing the aspect and figure of Africa.
 4 The domestic servants have advanced far before them in 
VARIETIES OF MANKIND.
417
4 acquiring the agreeable and regular features,  and the
4 expressive countenance of civilized society. The former
4 are frequently  ill shaped, they preserve, in a great de-
4 gree, the African lips, and nose and hair. Their genius
4 is dull, and their countenance sleepy and stupid.  The
4 latter are  straight and well proportioned, their hair ex-
pended to  three or four, sometimes even to six  or eight
' inches : the  size and shape of their mouth handsome,
4 their features regular, their capacity good, and  their
4 look animated.'*
   Dr. Prichard has 4 been assured, by persons who have
4 resided in the West Indies, that a similar change is
4 very visible among the Negro slaves of the ihird and
4 fourth generation in those islands, and that the first ge-
4 neration differs considerably from the nati ves of Africa.'j
   The South Sea Islanders, who appear to be all of one
family, vary according to their degree  of cultivation.
The  New  Hollanders, for example,  are savages, and
chiefly black ; the New Hollanders are half civilized, and
chiefly tawny; the Friendly Islanders are more advanced,
and are not quite so dark ; several are lighter than olive
colour, and hundreds of European faces are found among
them.
   The  people of Otaheite and the Society Isles are the
most civilized and the most beautiful:  the higher orders
among them have a light complexion,  and  hair  flowing
in ringlets ; the lower  orders, less cultivated,  are less
pleasing.
   44 The same superiority," says Captain King,:}: 4 which

  * On the Causes of the Variety in the Complexion and Fisrure of the
human species, p. 85. sq.
  f 1. c. p. 227. note.
  i Cook's Voyages. Vol. 3. book 5. ch. 7 
418
VARIETIES OF MANKIND.
 4 is observable in the Erees (nobles) throughout the other
 4 islands, is found also here (Owyhee.) Those whom we
 ' saw were, without exception,  perfectly well formed;
 4 whereas the lower sort, besides their general inferiority,
 4 are subject to all the variety of make and figure  that is
 4 seen in the populace of other countries."
   Climate, however, has not been shewn to have no ef-
 fect : but its power, being greatly inferior to that of civi-
 lization  and barbarism, cannot  strongly manifest itself,
 when acting in opposition to these. In fact, a diminution
 of the sun's influence does dispose to the production of
 light  varieties : the  inhabitants  of hilly situations are,
 caeteris paribus, fairer than the people below, and persons
 of the same tribe and degree 6*f civilization are whiter in
 the northern parts of Europe and Asia, than their more
 southern neighbours; whiteness, too, is very common in
 the north, among  animals, which, nearer the equator,
 are variously coloured.  A pair of brown mice, kept in
 a dark place, generate a white offspring.
  Perfection, in other words, the highest compatible point
 of utility or agreeableness, or of both, is nature's univer-
 sal aim in her productions, but it is in general obtained
 slowly,  and the more so, in proportion to the excellence
 or degree of the qualities to be perfected.  Animals and
 vegetables  have to pass one period, before they burst into
 birth, and  another, before their full powers and propor-  *
 tions are reached ;  and man, whose perfections are very
 excellent, arrives at his acme very late.
  It is in this respect with  species as with individuals,—
 their improvement is  gradual.  In conformity with these
observations, we must  suppose  that man was once far
below the excellence of which he  is susceptible,—that 
VARIETIES OF MANKIND.
419
this was to be acquired slowly; and that, in consequence,
the Caucasian variety did not once exist.
   If we believe that he was  created in perfection, we
must believe, that, after the fall,  his nature experienced
the general change; that he became destitute and wretch-
ed,  and  destined to reach perfection  by slow degrees.
That he was once black, is rendered extremely probable,
by the analogy  of  animals,  among which  Mr. Hunter
remarked,  that the changes of colour were always from
the darker to the lighter tints.*
   It would appear  also, from history, that  the most an-
cient people  of the  earth, from whom Europeans are de-
scended, were genuine  Ethiopians or Negroes.f
  * 'Animals, living in a free and natural state, are subject to few de-
 ' viations from their specific character;  but nature is less uniform in
 ' its operations, when influenced by culture.  Considerable varieties
 •are produced under such circumstances; of which the most frequent
 * are changes in the colour.
  ' These changes are always, I believe, from the dark to the lighter
 ' tints;  and the alteration very gradual  in certain species, requiring,
 • in the  Canary-bird, several generations ; while  in the crow,  mouse,
 « &c. it  is completed in one.  But this change is  not always to white,
 ' though still approaching nearer to it in  the young than in the parent;
 ' being sometimes to dun, at others to spotted, of all the various shades
 ' between the two extremes. This alteration in colour being constantly
 ' from dark to lighter, may we not reasonably infer, that in all animals
 ' subject to such variation, the darkestof the species should be reckoned
 « nearest to the original; and that, where there are specimens of a parti-
.' cular kind, entirely black, the whole have been originally black? With-
 ' out this supposition, it will be impossible, on the principle I have stat-
 «ed, to account for individuals of any class being black. Every such vari-
 «ety may be considered as arising in the cultivated stateof animals.' Hun-
 ter, On the colour of the pigmentum nigrum of the eye.  Obs.  p. 243.
   f See Pritchard's Physical History of  Man.  Ch. vii. viii. ix.
   I shall take this opportunity of noticing monsters 
420
VARIETIES OF MANKIND.
   The history of mankind  supports the same inference,
as considerations a priori, and analogical and direct facts.
All the  nations  of  the  earth appear  to have branched
forth from one quarter.   Dr. Pritchard  has traced them
with great learning and judgment, and as the subject has
  Mr. Lawrence has collected most of the remarkable and well authen-
ticated instances ef monsters, in a paper published in the fourth volume
of the Medico-Chirurgical Transactions. To this 1 refer for examples.
He divides monstrosity into unnatural formation, unusual position of
certain organs, deficiency, redundancy, and a mixture of these.
  No one, in the present day, would ascribe monstrosity to any thing
else than an error in the original materials of the embryo,—to a mix-
ture of the whole or a part of the materials of two or more embryos,
to a deficiency in the materials, or to a derangement of  them.  (See
Sect. xl.  587. 3. 588. 591)
  Culture, we find, produces alterations'in animated beings  If it pro-
ceeds no, farther than to afford a supply to all  the natural wants of a
system, it improves the species, as is exemplified daily in vegetables.
"It may certainly be laid down, says Mr. Hunter, (1. c. p. 245. note.)
as one of the principles or laws of nature,  to  deviate under certain
circumstances.   It may also be observed, that  it is neither necessary,
nor does it follow, that all deviations must be a falling off: it appears
just the contrary; therefore we may suppose, that nature  is  improving
its works, or, at least, has established the principle of improvement in
the body as well as  in the  mind."  If, however, luxurious abundance
is supplied, or important natural habits of the system prevented, as is
not rarely the case in domesticated animals  and civilized man, devia-
tion may advance beyond improvement, and actually become degene-
ration or monstrosity. Hence the commonly known fact (591) of mon-
sters being  frequent among domesticated animals, and rare among the
wild. As man, by his depravity, commits errors and excesses of every
 description, unnecessarily mingling ill effects  with the benefits of ci-
 vilization,  no wonder  that monsters are common among the human
 species. The evils of civilization are not necessarily united with it,
 and, great as they are, they fall infinitely short of its benefits. Without
 civilization population must be wretchedly small, exigencies and com-
 forts miserably supplied, and none of the noble characteristics of the 
VARIETIES OF MANKIND.
421
not  been  made  by myself a matter of original research,
and is far too extensive to be handled here as it deserves,
I  must refer to his work, which is both the most recent
and the best, contented with simply inserting his conclu-
hcart and mind fully called forth :  in the uncivilized state, on which
Mr. Lawrence  is disposed to bestow such eulogies,  this gentleman's
superiority would not have been conspicuous.
  Mr. Lawrence, I mention it with pain, draws, from the occurrence of
monsters, an argument  unfavourable to the belief of the goodness of
the Almighty.  This, I am aware, is not the place to ' assert eternal
providence, and justify  the ways of God  to man ;' but, in recommend-
ing the student to a work, it is my duty  to guard him against its dis-
advantages.  " Neither should we overlook these productions, (says
this  gentleman) in our attempts to infer, from the phenomena of na-
ture, and particularly from organized beings, the character of the cause
which has produced them. Creatures so imperfectly constructed, as to
be incapable of independent vitality, and consequently perishing imme-
diately after they are born ;  and those whom the malformation of some
organ draws, after a life of  pain and misery, afflicting to themselves,
and burthensome to others, to a premature death, offer an apparent
exception to the inferences  which have been drawn from the animal
kingdom in general, concerning some attributes of the  creating pow-
er."  " Archdeacon Paley has passed over the subject in silence."
   The world,  it must be remembered, is governed, not by partial, but
by general laws, and the least reflection will shew, that any alteration
which  a  human being could propose in  them  would produce infinite
mischief.  In particular circumstances, however, the good they gene-
rally cause is certainly converted into evil.  Hunger is one of the
great sources of activity and enjoyment among men and animals ; but,
 in particular circumstances, where it cannot possibly be gratified,  it
is a torment.  The laws of each species of organic formation produce
the beautiful animated system ; but these same laws, under particular
'hwarting circumstances,—when crossed by other general laws,  pro-
duce monsters.  The case of monsters is but one of numerous similar
 "samples ; and although  the great Paley has not noticed this example
 individually,  he notices all  such in general.  "Contrivance proves 
422
VARIETIES OF  MANKIND.
sion,  which is the same as Bryant's, although founded
on different principles.
  " The countries,  bounded on the east and west by the
Ganges and the Nile,  on the north by the Caspian  lake,
       design; and the predominant tendency of the contrivance indicates the
       disposition of the designer.  The world abounds with contrivances;
       and all the contrivances which we are acquainted with are  directed
       to beneficial purposes.  Evil, no doubt, exists; but is never, that we
       can perceive, the object of contrivance.  Teeth are contrived to eat,
       not to ache; their aching now and then is incidental to the contri-
       vance, perhaps inseparable from it, or even, if you will, let it be call-
       ed a defect in the contrivance ; but it is not the object of it.   This  is
       a distinction which well deserves  to be attended to.   In describing
       implements of husbandry, you would hardly say of the sickle, that  it
       is made to cut the reaper's fingers, though, from the construction of
       the instrument, and the manner of using it, this mischief often hap-
       pens.   But if you had occasion to  describe instruments of torture or
       execution, this engine,  you would say, is to extend the sinews; this
       to dislocate the  joints; this to break the bones ;  this to scorch the
       soles of the feet.  Here, pain and misery are the very objects of the
       contrivance. Now nothing of this  sort  is to be found in the works of
       nature.  We never discover a train of contrivance to bring about an
       evil purpose.  No anatomist ever discovered a system of organization
       (i e. no species of system of organization, for the laws of the forma-
       tion of an individual are the general laws of the  species to which it
       belongs) calculated to produce pain and disease ; or, in explaining the
       parts of the human body, ever said, this is to irritate ; this to inflame ;
       this duct is to convey the gravel to the kidneys ; this gland to secrete
'      the humour which forms  gout.  If,  by chance, he come at a part of
       which he knows not  the use, the most he can say is, that it is useless:
       no one ever suspects that it is put there  to incommode, to annoy, or to
       torment.  Since then God hath called forth his consummate wisdom,
       to contrive and provide  for  our happiness, and the world appears to
       have been constituted with this design at first, so long as  this consti-
       tution is  upholden by Him, we must in reason suppose the same de-
       sign to continue."  Moral Philosophy, vol. i. p. 76. 
VARIETIES  OF MANKIND.
423
and the mountainous ridges of Paropamisus and Imaus,
and on the south by the Erythraean sea, or Indian ocean,
appear to have been the region, in  which mankind first
advanced  to civilization.   It is  highly probable,  that
these countries were the primitive abode of  our species,
in which alone, therefore, it can properly be considered
as indigenous.
   " In the first ages, previous to the origin of the most
simple arts, while men were as yet too rude to acquire  *
their  sustenance by hunting, (or, if we receive the scrip-
tural  account of the deluge, before the. woods were filled
with  wild animals,) they apparently obtained their food
chiefly by fishing along the sea shores, or depended for a
still more  precarious supply on the scanty fruits of the
earth.  In this state,  they would, of necessity,  lead a
  Even where evil is produced, such is the mighty universal plan, that
it proves not simple, solitary evil, but becomes the cause of innumer-
able good effects.  A severe misfortune  has often  converted a proud
and prejudiced  man into  one of modesty and candour.  Again,  the
stupendous wisdom and the benevolence of the Almighty are conti-
nually manifested, in the operation of one general law, preventing the
particular evil  resulting  occasionally  from the clashing effects of
others. ^ Thus,  the greater number of monsters perish in the womb;
of those which are born, many die the moment of their birth, or a few
days afterwards; of those which survive, many die during childhood;
and of those few which grow up, very few reach, and perhaps none,
whose singularity is very great, pass, the middle period of life,  and
their organs of  procreation are often languid, if not perfectly ineffi-
cient :  nor,  in fact, do I believe, from my observation, that many of
them are at all less happy than other people.
  But I blush to think it has been necessary to advocate the cause of
the Almighty.  Can any one refuse to
       Find tongues in trees, books in the running brooks,
       Sermons in stones, and good in every thing > 
424
VARIETIES OF MANKIND.
wandering life,  and extend themselves widely.   Differ
ent tribes of ichthyophagi, or of roaming savages, were
scattered on each side of the primitive region, wherever
an easy progress lay open to them, along the coast or
through the woods of Africa, and around the shores of
the Indian islands  of  New Guinea, and  Australasia.
The descendants of these dispersed races are still found
in the same abodes, nearly in their original unimproved
condition, savages and negroes, such as we have seen
that the stock of their ancestors, the primeval inhabitants
of Egypt and India, were.
   " These were  the most ancient colonies, which emi-
grated into the distant parts  of the earth.   Accordingly,
they exhibit no affinities with the central nations, in their
languages, manners, or superstitions.   For they went
forth when language was as  yet imperfectly formed, be-
fore manners had acquired  any peculiar character,  and
previous to the age of idolatry.
   " The condition of mankind, in their primeval seats,
improved. They became hunters, and  afterwards shep-
herds.  Sabaism, or the worship of the  heavenly  bodies,
now prevailed among them.  Some tribes of hunters, and
perhaps of shepherds, ascended the chain of Paropamisus,
and spread themselves gradually over the  high  central
plains of Asia, on one side into Siberia and Scandinavia,
and on the other into Kamtschatka, and through the adja-
cent, and probably then connected, continent of America.
These are the Mongoles, and  other similar races, whom we
have traced through Asia and the north of Europe,  and
the primitive inhabitants of the New World. In the lan-
guages of these nations, though much diversified, and very
imperfect in structure, a certain degree of affinity  may be
clearly marked.  In their superstitions, vestiges remain of
the primitive Sabaism, even in their more distant settle- 
VARIETIES OF  MANKIND.
42 j
inents.  Their  physical characters  resemble*.  In other
particulars, proofs may be collected in many remote re-
gions, of the common origin of these races.
  " Meanwhile  agriculture  was invented in Asia,  and
the division of  labour connected with the institution of
casts, which  seems to have extended through  all the
primitive regions, gave a new character  to human so-
ciety.  The establishment  of a governing  or military
class, and of a  sacerdotal class, gave birth  to political
order.  The priests mingling allegory and fable with the
early Sabaism, and with the relics of genuine theism and
true  historical  tradition, which had probably been  pre-
served in a few families,  formed a complex system of
mythology.  The mysteries were invented.  Philosophy
began to be cultivated, and a more perfect language was
formed.
  " The Celtae  under their  Druids, a branch of the east-
ern hierarchy, advanced into the  furthest west, where
perhaps  some vestiges of  previous colonists may be
found.  They carried with them the mysteries, the doc-
trine of metempsychosis, the rites of polytheism, the  phi-
losophy, and the language of the east.
  " The Pelasgian and Thracian races established them-
selves  in Asia  Minor and  passed the Hellespont  into
Thrace.  The former colonized Greece  and Italy; the
latter passed to the northward of the  Danube  into the
Dacian or Getic country.  Tribes of this nation wander-
ed at a later period through the  forests of Germany,
where  they multiplied and  encroached upon the Celtae.
Lastly, the Medes, delighting in  their herds of  horses,
advanced through the Euxine borders into Scythin and
Sarmatia.
                         T :' 
426           VARIETIES  OF MANKIND.

  " That  all these nations, the  Celts,  the  Pelasgi, the
Goths, and the  Sarmatse, were comparatively late colo-
nists from Asia, we may safely assert, when we consid-
er the strong affinities discoverable in their systems, in
their religious rites and doctrines, and  in their dialects,
which are dearly branches of the Sanscrit and old Per-
sic, and  when  we  remark that most of them may  be
traced in history still preserved, from their primitive
settlements  in the East."
   Our inevitable conclusion thus  coincides with the
Mosaic account—that the whole  human race is the off-
spring of the same parents.
THE END. 
 
 
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