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PHYSIOLOGY  OF  DIGESTION
CONSIDERED WITH RELATION TO
THE PRINCIPLES OF DIETETICS.
       BY ANDREW COMBE, M.D.


FELLOW or THE ROYAL COLLEOE OF PHYSICIANS OF EDINBURGH j
  rHYIICIAIf EXTRAORDINARY TO THE O.UEEN IN SCOTLAND,
     AND CONSULTING PHYSICIAN TO THE KINO AND
            QUEEN OF THE BELGIANS.
  " Nor is it left arbitrary, at the will and pleasure of every man, to
do as he list; after the dictates of a depraved humour and extrava-
 fant phancy, to live at what rate he pleaseth ; but every one is
 ound to observe the Injunctions and Law of Nature, upon the pe-
nalty of forfeiting their health, strength, and liberty—the true and
long enjoyment of themselves."—Mainwatringe.
FRO* THE THIRD EDINBURGH REVISED AND ENLARGE* EDITIOW.  ^»B^v^
WITH ILLUSTRATIONS.
iw**V
        XEW YORK:  '      ^-----   |
WILLIAM H.  COLYEr/^RAY
    No. 5 Hague-street.

        BOSTON:
LEWIS &  SAMPSON,

          1844. 
ArtT^
 wx 
ADVERTISEMENT

               TO THE

        THIRD EDITION.
   The first edition of the present volume consisted of two
thousand  copies, and was exhausted in little more than five
months.   The second  extended to the very unusual number
of four thousand copies, and has now been for some weeks out
of print.  In the United States the work has also been twice
republished.  This success is very gratifying, and affords a
very encouraging indication that the importance of physiolo-
gical knowledge as a branch of general instruction is every day
becoming better understood and more extensively recognised.
  In the edition now in the hands of the  reader various im-
provements have been effected.   Of these the most important
has been the introduction of a new chapter, explaining more
fully the relation subsisting between the  different kinds of
food and the principal varieties of the human  constitution.
Several other improvements, of a still more extensive kind,
had also occurred to me, but long-continued indisposition has
prevented me from carrying them into effect.  In this uncer-
tainty, it seemed to me bette.r rather to reprint the work with
such alterations as I was able to make on it, than to defer its
appearance for an indefinite time ; and 1 trust that most of my
readers will concur in thinking that in this I have  decided
correctly.  With these  apologetic remarks, 1 must now leave
the work, with all its remaining imperfections, to the kind
indulgence of the public.

  Edinburgh, 25 Rutland-street,
October 15,1841. 
 
PREFACE.
   The present volume is essentially a continuation of tire
work of which the tenth edition has lately appeared, under the
■title of " The Principles of Physiology applied to the Preser-
vation of Health and to the Improvement of Physical and
Mental Education ;" and  its object is the same—namely,  to
lay before the public a plain and intelligible description of the
structure and usesof some of the more important organs of the
human body, and to  show how information of this kind  may
be usefully applied, not only in the prevention of suffering, but
in improving the physical, moral, and intellectual condition
of man.
   At first sight it may seem doubtful to many of my readers
whether I have not exceeded proper bounds in dedicating a
whole volume  to the consideration of the  single subject of
Digestion ;  but  the more  we consider the  real complication
of the function, the extensive influence which its  varying
states exercise at every period of life over the whole of the
bodily organization, and,  consequently, over our moral and
intellectual nature, and the degree  to which its  morbid de-
rangements undermine health, happiness, and  social useful-
ness, we shall become more and more convinced of the deep
practical interest which attaches  to a familiar acquaintance
with the  laws by which it is regulated, and of the necessity
of entering into their examination at sufficient length to ensure
the ready applicability of  our  knowledge in our general  con-
duct.  In  infancy errors  in diet and  derangement of the
digestive organs are admitted to be among the principal causes
of the striking  mortality which occurs in that period of  life.
In youth and maturity the same influence is recognised, not
only in the numerous forms of disease directly traceable to that
origin, but  also in the  universal practice of referring every
obscure or anomalous disorder to derangement of the stomach
or bowels.   Hence, too, the interest which has always beer-
felt by the public in the perusal of books on Dietetics  and
Indigestion ; and hence the prevailing custom of using purga-
tives  as  remedies for every disorder, very often with good,
but not unfrequently with most injurious effects.
  Numerous and popular, however, as writings on Dietetics
bave been, and excellent  as are many of the precepts which
have been handed down by them from the earliest ages, sanc-
tioned by the warm approval of every successive generation, 
 ,JT                      PREFACE.

  it is singular how very trifling their influence  has been, and
  continues to be, in altering the hahits of those  to whom they
  are  addressed.  In a general way, we  all acknowledge that
  diet is a powerful agent  in modifying  the animal economy ;
  yet, from our conduct, it might justly be inferred, that we either
  regarded it as totally devoid of influence, or remained in utter
  ignorance of its mode of operation, being left to the guidance
  of chance alone, or of notions picked up at random, often at
  variance with reason, and, it may be, in contradiction even
  with our own daily experience.
    In thus attempting to direct public attention to the more
  careful consideration of a subject which he  conceives to  be
  deeply interesting to their welfare, the Author does not enter-
  tain the  hope that  his work will immediately produce any
 perceptible change in .the general practices of society, or that
 he will so far  shake the force of habit as to induce many
 healthy men of mature age to forsake their accustomed regi-
 men merely because it is  at variance with the laws of Nature.
  But he is, nevertheless, willing to believe that,  among valetu-
 dinarians and the young of both sexes,, whose  habits are not
 formed, and numbers of whom err as much from ignorance  as
 from the force of passion, many may be found who will be glad
 to obtain the  guidance of knowledge  and principle in the
 regulation of their mode of life ; and that even  many parents,
 who may not have resolution enough to forsake mischievous
 indulgences to which they have long been accustomed, may,
 nevertheless, be anxious to avail themselves of any assistance
 on which they can depend for  the better bringing up of their
 children.  If in these expectations he is not too sanguine, the
 future  advantage to the  race  from the present diffusion  of
 dietetic knowledge is as  certain, and almost as encouraging,
 as if its  effects  were instantaneous  on both old and young.
. In the march of human improvement, months and years count
 but  as moments.  The men of to-day  will soon have acted
 their parts, and given place to those who are now with youth-
 ful energy adding to their  knowledge, and throwing off a
 portion of the prejudices of their fathers. They in their turn
 will speedily be succeeded by their  children,  and the appa-
 rently speculative but really practical discoveries of the one
 generation will thus become  the  established and  influential
 truths of the next.  In this way every individual change in the
 habits of society may be so slow and minute as at the moment
 to escape our notice, but it is not on that account the less real.
 Nobody who compares the coarse feeding and  riotous convi-
 vialities  of our forefathers, at  the beginning of last century,
  with the more refined and temperate habits of the present day,
 will think of denying that a prodigious step has been made  in
 the  interval even with respect to eating and  drinking, pro-
  cesses so often considered as beyond the influence of reason. 
PREFACE.                       V
And yet, if we were required to point out any single year of
the whole  century during which a marked reformation took
place, we should not be able to do so.  This being the case,
then, can we, their descendants, maintain that we are arrived
so nearly at perfection as to leave no room for corresponding
improvement in our day, however slow it may also be ?   My
conviction is so much the reverse, that it seems to me certain
that our onward  progress will continue through generations
yet unborn, with the same steadiness as it has  done through
generations long  since  gathered to their  fathers ;  and that
every attempt made to render man better acquainted with the
Jaws of his own  constitution, and thereby provide him with
fixed and better principles of action, will exert a positive and
decided influence on the progress of the race, proportioned in
extent to the truth, clearness, and general applicability of the
views which are unfolded. On such considerations do I ground
my hope that the present volume, notwithstanding its nume-
rous defects, will (in so far as  it  really imbodies truths of
practical importance) contribute in its own limited sphere to
the general end.
   The real cause of the little regard paid to dietetic rules—
and it is of consequence to remark it—is not so much indiffe-
rence to their influence, or even the absolute  want of valuable
information, as the faulty manner in which the subject is usual-
ly considered.  In many of our best works  the relation subsist-
ing between the human body on the one hand,  and the qualities of
alimentary  substances on  the other, is altogether  lost sight of,
although it is the  only solid principle on which  their proper
adaptation to each other can be based.  In  this manner, while
the attention is carefully directed to the consideration of the
abstract qualities  of the different kinds of aliment, little or no
regard is paid to the relation in which they stand to the  indi-
vidual constitution, as modified by age, sex,  season, and cir-
cumstances, or to the observance of the fundamental laws of
digestion.  And hence, although these conditions are not un-
frequently of much greater  importance to the general health
than -even  the  right selection of food, yet, when indigestion
arises from neglecting them, the food alone is  blamed, and
erroneous conclusions aro drawn, by relying  on which, upon
future occasions, we may easily be led into still more serious
mistakes.
   It is, indeed, from being left in this way without any guid-
ing principle to direct their experience,, and test the accuracy
of the precepts laid down to thein for the  regulation of their
conduct, that many persons begin by being bewildered by the
numerous  discrepancies which they met with between facts
and doctrine, between counsel and experience—and  end by
becoming entirely skeptical on the subject of all dietetic rules
                          •  1* 
 *I                     PREFACE.

 whatever, and regarding them as mere theoretical effusions,
 based on fancy, and undeserving of a moment's consideration.
   The true remedy for this state of things is, not to turn away
 in disgust and despair, but to resort to a more  rational mode
 of inquiry—certain that, in  proportion as we advance, some
 useful result will reward our labours.  Such, accordingly, has
 been my aim in the present publication , and if I shall be found
 to have been even moderately successful in attaining it, I shall
 rejoice in the confident conviction that others will be led to
 still more positive and beneficial results.   Utility has been my
 great object throughout.  In following  what I conceive to be
 an improved mode of investigation, I have in some instances
 placed known facts in a new point of view, and deduced from
 them practical inferences of considerable value and easy ap-
 plication : but beyond this I am not ambitious of originality ;
 and if I have anywhere used expressions which may seem to
 do injustice to others, it has been entirely without any such
 design, and, consequently, I will be prompt to  acknowledge
 my error and rectify the involuntary mistake.
   In the  previous  editions of this volume I stated that I had
 derived the  utmost advantage from a very valuable work  by
 Dr. Beaumont, an  American writer, which—though  faulty in
 its arrangement, and necessarily defective in many  essential
 particulars—contains an authentic record of some of the most
 curious  and instructive observations which have ever been
made on the process of digestion.  That excellent and  en-
lightened physiologist had the rare good fortune to meet with
 a case where an artificial opening into  the stomach existed,
through which he could see everything that took place  during
the progress of healthy digestion ;  and, with the most disin-
 terested  zeal and  admirable  perseverance, he proceeded  to
avail himself of the  opportunity thus afforded of advancing
human knowledgs,  by engaging the patient, at a heavy expense,
to live with him for several years, and become the subject of
numerous and carefully  conducted experiments.   Having,
through the kindness of a friend resident in the United States,
been early favoured with a copy of the original work, I felt so
strong a conviction of the superior value of investigations con-
ducted under circumstances so unusually free from the many
sources of fallacy inseparable  from experiments on  animals,
that at llie time I had almost  resolved to reprint it entire, both
 as an act of justice to Dr. Beaumont, and as a valuable con-
 tribution to  physiological science.  In the  belief, however,
 that a republication would immediately appear from some other
quarter, I abstained from doing so, and contented myself with
 making free use of  such parts of it as seemed most calculated
 to throw  light upon the practical questions which I was en-
 gaged in  discussing.  But after waiting in vain for two years. 
PREFACE.                     Til
and finding the interest excited in Dr. Beaumont's experiments
increased in proportion as their nature and value became more
extensively known by means of the extracts given in the pre-
sent volume, I felt it due to Dr. Beaumont to delay no longer,
and  accordingly republished  his work with the addition of
various explanatory and  practical notes,* and the high favour
with which it has been welcomed by the leading medical jour-
nals shows that I did not exaggerate its importance.
  Dr. Beaumont's work  being thus rendered accessible to the
English reader, I was anxious, ii) the present edition, to omit
as much of the matter formerly extracted from it as I possibly
could.  But, on making the attempt, I found the extracts every-
where  so mixed up with the practical conclusions which they
were used to enforce, that I could not leave them out without
materially weakening the argument.  I have, therefore, retain-
ed them ; and an additional reason for doing so was, that Dr.
Beaumont's volume is in the hands almost exclusively of pro-
fessional men, and is thus likely to remain almost as little
known to the  general reader as if it  were still confined in
circulation to the other side of the Atlantic.
  Objections may be stated to several of the repetitions which
occur in the following  pages.  The only apology I have to offer
for them is,  that I committed them deliberately, because they
seemed to me necessary to ensure clearness, and because the
intimate manner in which the different functions are connected
with each other sometimes made it impqssible to explain one
without again referring to  the rest.   My prime  objects being
to render the meaning unequivocally plain, and  impress the
subject deeply upon the reader's mind, I thought it better to
risk in this way the occasional repetition of an important truth,
than to leave it in danger of being vaguely apprehended or its
true value unperceived.   For these  reasons, it is hoped that
the fault—if such it is—will be leniently overlooked.

  * Experiments and Observations on  the Gastric Juice and the
Physiology  of  Digestion, by William Beaumont, M.D.,  of the
United States Army. Reprinted with Notes  by Andrew Combe,
M.D  1 vol. post 8vo  Edinburgh, 183S 
 
CONTENTS.
                         PART  I.
              PHYSIOLOGY OF DIGESTION.

                      CHAPTER I.
 GENERAL VIEW OF THE OBJECTS AND LAWS OF NUTRITION.
 Waste or loss of substance always attendant on action—In the ve-
  getable and animal kingdoms waste is greater than in the phy-
  sical—Living bodies are distinguished by possessing the power
  of repairing waste—Vegetables, being rooted in one place,  are
  always in connexion with their food—Animals, being obliged to
  wander, receive their food at intervals into a stomach—Nutrition
  most active when growth and waste are greatest—In vegetables
  the same causes which increase these processes also stimulate
  nutrition—But animals require a monitor to  warn them  when
  food is needed—The sense of Appetite answers this purpose—
  The possession of a stomach implies a sense of Appetite to regu-
  late the supplies of food.                                25-31

                     CHAPTER II.
         THE APPETITES OF HUNGER AND THIRST.
 Hunger and Thirst, what they  are—Generally referred to  the
  stomach and throat, but perceived by the brain—Proofs and illus-
  trations—Exciting causes of hunger—Common theories unsatis
  factory—Hunger sympathetic of the state of the body as well as
  of the stomach—Uses of appetite—Relation between waste and
  appetite—Its practical importance—Consequences of overlooking
  it illustrated by analogy of the whole animal kingdom—Disease
  from acting in opposition to this relation—Effect of exercise on
  appetite explained—Diseased appetite—Thirst—Seat of Thirst—
  Circumstances in which it is most felt—Extraordinary effects of
  injection of water into  the veins in cholera—Uses of thirst, and
  rules for gratifying it.                                  31-51

                     CHAPTER  III.
      MASTICATION, INSALIVATION, AND DEGLUTITION.
 Mastication—The teeth—Teeth, being adapted to the kind of food,
  vary at different  ages  and in different animals—Teeth classed
  and described—Vitality of teeth, and it3 advantages—Causes of
  disease in teeth—Means of protection—Insalivation, and its uses
  —Gratification of taste in mastication—Deglutition.        51-63

                     CHAPTER  IV.
ORGANS OF DIGESTION--THE STOMACH—THE GASTRIC JUICE.
Surprising  power of digestion—Variety of sources of food—All
  structures, however  different, formed from the same blood—Ge-
  neral view of digestion, chymification, chylification, sanguifica-
  tion, nutrition—The stomach in  polypes, in quadrupeds, and in
  man—Its position, size, and complexity in different animals—Its
  structure ; its peritoneal, muscular, and villous coats ;  and uses
  of each—Its.nerves and bloodvessels ; their nature, origins, and
  uses—The former the medium of communication between the
  brain and stomach—Their relation to undigested food—Animals 
 K                      CONTEXTS.

   not conscious of what goes on in the stomach—Advantages of thit
   arrangement—The gastric juice the grand  agent in digestion-
   Its origin and nature—Singular case of gunshot wound making a
   permanent opening into the stomach—Instructive experiments
   made by Dr. Beaumont—Important results.                63-99

                      CHAPTER V.
             THEORY  AND LAWS OF DIGESTION.
 Different theories of Digestion—Concoction—Fermentation—Putre-
   faction—Trituration—Chemical solution—Conditions or laws of
   digestion^Influence of gastric juice—Experiments illustrative of
   its solvent power—Its mode of action on different kinds of aliment;
   beef, milk, eggs, soups, &c.—Influence of temperature—Heat of
   about 100° essential to digestion—Gentle and continued agitation
   necessary—Action of stomach in admitting food—Uses of its
   muscular motion—Gastric juice acts not only on the surface of
   the mass, but on every particle which it touches—Digestibility
   of different kinds of food—Table of results—Animal food most di-
   gestible—Farinaceous next—Vegetables and soups least digestible
   —Organs of digestion simple  in proportion to concentration of
   nutriment—Digestibility depends on adaptation of food to gastric
  juice  more than an analogy of composition—Illustrations—No
  increase of temperature during digestion—Dr.  Beaumont's sum-
   mary of inferences.                                   99-129

                    .  CHAPTER VI.
    CHYLIFICATION, AND THE ORGANS CONCERNED IN IT.
Chyliflcation—Not well known—Organs  concerned in  it—The
  intestinal canal—Its general structure—Peritoneal coat—Mesen-
  tery—Muscular coat—Uses of these—Air in intestines—Uses of
  —Mucous coat—Analogous  to skin—The seat  of excretion and
  absorption—Mucous glands—Absorbent vessels—Course of chyle
  toward the heart—Nerves of mucous coat—Action of bowels ex-
  plained—Individual structure of intestines—The duodenum; jeju-
  num" ; and ileum—Liver and pancreas concerned in chyliflcation
  —Their situation  and uses—Bile, its origin and uses—The pan-
  creas—Its juice—The jejumim described-t-The ileum ; coacum ;
  colon ; and rectum—Peristaltic motion of bowels—Aids  to it—
  Digestion of vegetables begins in stomach, but often finished in the
  bowels—Illustration from the horse—Confirmation by Dupuy-
  tren.                                               129-152


                        PART II.

THE  PRINCIPLES OF DIETETICS VIEWED  IN RELATION
            TO THE LAWS OF DIGESTION.
                     CHAPTER I.
                     TIMES OF EATING.

The selection of food only one element in sound digestion__O.Lat
  conditions essential— Times of eating—No stated hours for eat-
  ing—Five or six hours of interval between meals generally suffi- 
CONTENTS.                       xJ
  clent; but must vary according to circumstances—Habit ha*
  much influence—Proper time for breakfast depends on constitu-
  tion, health, and mode of life—Interval required between break-
  fast and dinner ; best time for dinner ; circumstances in which
  lunch is proper ; late dinners considered ; their propriety depen-
  dant on mode of life—Tea and coffee as a third meal; useful in
  certain circumstances—Supper considered—General  rule as  to
  meals—Nature admits  of variety ; illustrations ; but requires
  the observance of principle in our rules.               153-175

                     CHAPTER II.
           ON THE PROPER QUANTITY OF FOOD.
Quantity to be  proportioned to the wants of the system—Appetite
  indicates these—Cautions in trusting to appetite—General error
  in  eating too  much—Illustrations from  Beaumont,  Caldwell,
  Head, and Abercrombie—Mixtures of food hurtful chiefly  as
  tempting to excess in quantity—Examples of disease from excess
  in servant-girls from the country, dressmakers, &c.—Mischief
  from excessive feeding in infancy—Rules for preventing this—
  Remarks on the consequences  of excess in grown persons—
  Causes of confined bowels explained—And necessity of fulfilling
  the laws which God has  appointed for the regulation of the animal
  economy inculcated.                                175-196

                     CHAPTER III.
CONDITIONS TO BE  OBSERVED  BEFORE AND  AFTER EATING.
General laws of organic activity apply to the stomach as well as to
  other parts—Increased flow of blood toward the stomach during
  digestion—Hence  less circulating in other organs—And, con-
  sequently, less aptitude for exertion in them—Bodily rest and
  mental tranquillity essential to sound digestion—Rest always
  attended to before feeding horses—Hence  also a natural aversion
  to exertion immediately after eating—Mischief done by  hurry-
  ing away to  business after meals—Severe thinking hurtful  at
  that time—Playful cheerfulness after dinner  conducive to  di-
  gestion—The mind often the cause  of indigestion—Its mode
  of operation  explained—Also influences nutrition—Illustration
  from Shakspeare—Importance of attending  to  this condition of
  health enforced.                                      197-207
                     CHAPTER IV.
   THE DIFFERENT KINDS OF CONSTITUTION AND OF FOOD
      CONSIDERED WITH RELATION TO EACH OTHER.

Man remarkable for the variety of his food; advantages of this —
  Man not guided by instinct to the choice of his food, but by ob-
  servation and experience ; his welfare thus intrusted to himself
  __Principle on which fitness of food ought to be determined; in-
  formation still much wanted—Nature of constitution to be con-
  sidered—Varieties of constitution or temperament; the lymphatic,
  nervous, sanguine, bilious, and mixed temperaments—Diet ought
  to be modified according to temperament; illustrations—Different
  kinds of food ; their classification and division into  animal and
  vegetable—Londe's propositions regarding their relative digesti-
  bility—Animal food and its varieties ; its chemical composition no 
XU                      CONTENTS.

  test oi Its dietetic qualities—Division into fibrinous, gelatinous,
  and urouminous meats—Adaptation of each of these to different
  temperaments, ages, and states of health—Vegetable aliments and
  their properties ; principal divisions of them, and general remarks
  on their use and adaptation.                           21W-231

                     CHAPTER V.
ADAPTATION OF  DIET TO CONSTITUTION, AGE, SEASON,  AND
                      MODE OF LIFE.
Food to be adapted to constitution  and circumstances—Diet must
  vary with time of life—Diet  in infancy—The mother's milk the
  best; substitutes for it—Over-feeding a prevalent error—Diet
  after weaning—Too early use of animal food hurtful—Diet of
  children in the higher classes too exciting ; and produces scro-
  fula—Mild food best for children—Incessant eating  very inju-
  rious—Proper diet from childhood to puberty—It  ought to be full
  and nourishing, but not  stimulating; often insufficient in board-
  ing-schools—Diet best adapted for mature age—Regimen powerful
  in  modifying the constitution, mental as well as physical—Far-
  ther investigation required.                           231-249

                    CHAPTER VI.
                        ON DRINKS.
Thirst the best guide in taking simple drinks—Thirst increased by
  diminution of the circulating fluids—The desire for liquids gene-
  rally an indication of their  propriety—Much  fluid  hurtful at
  meals—Most useful three or four hours later—The temperature
  of  drinks is of consequence—Curious fall of temperature in the
  stomach from cold water—Ices hurtful after dinner—Useful in
  warm  weather, when digestion is completed and caution used—
  Cold water more dangerous than ice when the body is overheat-
  ed—Tepid drinks safest  and most refreshing after perspiration-
  Kinds of drink—Water safe for every constitution—Wine, spirits,
  and other fermented liquors too stimulating for general  use, but          (
  beneficial in certain circumstances—Test of their utility. 250-263

                    CHAPTER VII.
      ON THE  PROPER REGULATION OF THE BOWELS.
Functions of the intestines—The action of the  bowels bears a na-
  tural relation to the kind of diet—Illustrations—And also to the
  other  excretions—Practical  conclusions from  this—Different
  causes of inactivity of bowels—Natural  aids to intestinal action
  —General  neglect of them—Great importance of regularity of
  bowels—Bad health from their neglect—Especially at the age of
  puberty—Natural means preferable to purgatives—Concluding
  remarks.                                            264-276
Ikdex.                                               277-237
                      WOODCUTS.
  Under-jaw, 52.—Thoracic and Abdominal Viscera, 68.—Human
Stomach, 69.—Stomach of a ruminating animal, 71.__Villous Coat
of the Stomach, 75.—Opening into the Stomach of  Alexis  St. Mar-
tin, 85.—Abdominal Viscera, 132.—Transverse section of the Abdo-
men, 133.—Lacteals and Thoracic Duct, 138.—Thoracic  Duct, 139.
—Contents of the Abdomen after removal of the Intestines 143,—!
Mucous Coat oi the Duodenum, 145. 
                       PART  I.
      PHYSIOLOGY OF  DIGESTION.

                    CHAPTER I.
GENERAL VIEW OF THE  OBJECTS AND LAWS OF NUTRITION.
Waste or loss of substance always attendant on action—In the ve-
  getable and animal kingdoms waste is greater than in the phy-
  sical—Living bodies are distinguished by possessing the power
  of repairing waste—Vegetables, being rooted in one place, are
  always in connexion with their food—Animals, being obliged to
  wander, receive their food at intervals into a stomach—Nutrition
  most active when growth and waste are greatest—In vegetables
  the same causes which increase these processes also stimulate
  nutrition—But animals require a monitor to warn them when
  food is needed—The sense of Appetite answers this purpose—
  The possession of a stomach implies a sense of Appetite to regu-
  late the supplies of food.
   Throughout every department of  Nature waste is the
invariable result of action.   Even the minutest change in
the relative position of inanimate objects cannot be effected
without some  loss  of substance.  So  well is this  under-
stood, that it is an important aim in mechanics to discover
the best means of reducing to the lowest possible  degree
the waste consequent upon motion.  Entirely to prevent it
is admitted  to be beyond  the power of man ; for however
nicely parts may be adjusted to each  other, however hard
and durable their materials, and however smoothly motion
may go on, still in the course of time loss  of substance
becomes evident, and repair and renewal become indis-
pensable to the continuance of the action.
   It is thus a recognised  fact, or general law of nature, that
nothing can act or move  without undergoing some change,
however trifling  in amount.   Not even a breath of wind
can pass along the surface of the earth without altering in
some degree the proportions of the  bodies with which it
comes into contact ; and  not a drop of rain can fall  upon a
stone without carrying away  some portion of its substance.
The smoothest and most accurately formed wheel, running
along the most level and  polished railroad, parts with some
portion of its substance  at every revolution, and in process
of time is worn out and requires to be replaced.  The same
effect is forcibly, though  rather ludicrously, exemplified in
the great toe of the bronze  statue of St. Peter at  Rome,
which in the course of centuries has  been worn  down to
less than half its original size by the  successive kisses of
the faithful;  and I venture to mention it, because it  affords
one of the best  specimens of the operation of a principle, 
 26      WASTE ALWAYS ATTENDANT ON ACTION.

 the existence of which, from the imperceptibly small effect
 of any single act, might  otherwise be plausibly denied.
   As regards dead or inanimate  matter, the destructive
 influence of action is constantly forced upon our attention
 by everything  passing around  us; and  so much human
 ingenuity is exercised  to counteract its effects, that no re-
 flecting person will dispute the universality of its operation.
 But when we observe shrubs and trees waving in the wind,
 ami animals undergoing violent exertion, for year after year,
 and yet  both continuing  to increase in  size, we  may be
 inclined, on a superficial  view, to regard living bodies as
 constituting exceptions to the rule.  On more careful ex-
 amination, however, it will appear that waste goes on in
 living bodies not only without  any intermission, but with a
 rapidity immeasurably beyond  that which occurs in inani-
 mate objects.   In the vegetable world, for instance, every
 leaf of a tree is incessantly pouring out some portion of its
 fluids, and every flower  forming  its own fruit and  seed,
 speedily  to be separated from, and lost to, its parent stem ;
 thus causing in a few months an extent of waste many
 hundred  times greater than what occurs in the same lapse
 of time after the tree  is cut  down, and all its living opera-
 tions are at a close.   The same  thing holds  true in  the
 animal kingdom.   So long as life continues, a copious ex-
 halation from the skin, the lungs, the bowels, and the kid-
 neys goes on without a moment's intermission ; and  not a
 movement can be performed which does not at least partially
 increase  the velocity of the circulatijn, and add something
 to the general waste.   In this way, during violent exertion
 several  ounces of the fluids of the  body  are  sometimes
 thrown out by perspiration in a very few minutes ; where-
 as, after  life is  extinguished, all the excretions cease, and
waste is limited to that which results from ordinary chemical
decomposition.
   So  far, then, the law that waste is attendant on action,
applies to both  dead and  living bodies ;  but beyond this
point a remarkable difference between them presents itself.
In the  physical or inanimate world,  what is once lost or
worn away is lost  for  ever.  There is no power  inherent
in the piston of the steam-engine by which it can repair its
own loss of particles ;  and consequently in the course of
time it must either be laid  aside as  useless, or be remo-
delled by the hand of the workman.   But living bo;!j<\s
 whether  vegetable or animal,  possess  the distinguishing 
        LIVING BODIES CAN REPAIR THEIR WASTE.      27

characteristic of being able to repair their own waste and
add  to  their own substance.   The possession of such a
power is, in fact, essential to their very existence.   If the
sunflower, which in fine weather exhales thirty ounces of
fluid between sunrise  and sunset, contained no provision
within its own structure for replacing this enormous waste,
it would necessarily shrivel and die within a few hours, as
it actually does when plucked up by the roots ; and, in like
manner, if man, whose system throws  out every day five or
six pounds of substance by the ordinary channels of excre-
tion, possessed no means of repairing the loss, his organi-
zation would speedily decay and perish.  This very result
is frequently witnessed in cases of shipwreck and other
disasters, where, owing to the  impossibility  of obtaining
food, death ensues from the body wasting away till it be-
comes incapable of carrying on  the operations of life.   In
some instances this waste has even proceeded so  far  that
three-fourths of the whole weight of  the  body have been
lost  before life became extinct.
  It is  impossible to  reflect on these facts, and  others of
a similar kind,  without having  the conviction forced upon
our minds, that in every department of nature expenditure
of material  is inseparable from  action, and that in living
bodies waste goes on so rapidly, and by so many different
channels, that life could not be maintained for any length
of time  without an express provision being made for com-
pensating its occurrence.
  In surveying the respective modes of existence of vege-
tables and of animals, with the view of ascertaining by what
means this compensation is effected,  the first striking dif-
ference  between them which we perceive, is the fixfty of
position of the one, and the free  locomotive power of the
other.   The vegetable grows, flourishes,  and  dies,  fixed to
the same spot of earth from which it sprang ; and, however
much external circumstances may change around it, it must
remain  and  submit to their influence.   If it be deprived of
moisture and solar heat and  light, it cannot go in search of
them, but must remain to droop and to perish.  If the earth
to which its roots are  attached  be removed, and a richer
soil be substituted than that which its nature requires, it
still  has no option.: it must grow up in.rank and unhealthy
luxuriance, in obedience to an impulse which  it cannot re-
sist.  At all hours and at all seasons it is  at homo, and in
direct communication with the soil from which its nourish- 
28        ANIMALS RECEIVE FOOD AT INTERVALS.

ment is extracted.   And  being thus without ceasing m
contact with its food, it requires no store-house in which to
lay up provision, but receives immediately from the earth,
and at every moment, all that is necessary for its sustenance.
  But it is otherwise with animals.   These not only enjoy
the privilege of locomotion, but are compelled  to use it, and
often to go  to a distance, in  search of food and  shelter.
Consequently, if their vessels of nutrition were, like those
of vegetables, in direct communication with external sub-
stances, they would be torn asunder  at every movement,
and the animals themselves exposed either to die from star-
vation, or to forego the exercise of the higher functions for
which their nature is  adapted.  But the necessity for a
constant change of place being imposed on them, a diffe-
rent arrangement became  indispensable for their nutrition :
and the method by which the Creator hasremedied the incon-
venience is not less admirable than simple.   To enable the
animal to move about, and at the same time to maintain a con-
nexion with its food, He has provided it with a receptacle
or stomach, where it is able to store up a  supply of mate-
rials from which sustenance may be gradually elaborated
during a  period of time proportioned to its  necessities and
mode of  life.  It thus carries along  with it nourishment
adequate to its wants ;  and the small nutritive vessels im-
bibe their food^rom the internal surface of the stomach and
bowels, where the nutriment is stored up, just as the roots
or nutritive vessels of vegetables do from the soil  in which
they grow.   The possession of a stomach or receptacle for
food is accordingly a characteristic of the animal system  as
contrasted with  that of vegetables ; it is found even in the
lowest orders of zoophytes, which in other respects are  so
nearly allied to plants.
   The sole objects of nutrition being to repair waste and
to  admit of growth, Nature  has so  arranged that within
certain limits it is always most vigorous when growth  or
waste proceeds with the greatest rapidity.   Even in vege-
tables this relation is distinctly observable.   In spring and
summer, when vegetative life is most active, and when
leaves, flowers, and fruit are  to be  formed and growth car-
ried on, nourishment is largely drawn from the soil, and the
elaboration  and circulation of the  sap are proportionally
vigorous ;  whereas in winter, when  the leaves and flowers
have passed away, and vegetable life is  in repose, little
nourishment is needed, and  the circulation "of the sap  is 
        RELATION BETWEEN WASTE AND NUTRITION.    29

 proportionally slow.  In accordance with these facts, every
 one will recollect how freely a shrub or a tree bleeds, as it
 is called, when its bark is cut early in the season, and how
 dry it becomes on the approach of winter.   It is the activity
 of  the circulation in summer which renders its temporary
 suspension by transplanting so generally fatal at that season ;
 whereas, owing to the comparative sluggishness with which
 it is carried on in winter, its partial interruption is then at-
 tended  with much less risk.
   In vegetables  the quantity of  nourishment taken in en-
 tirely depends on, and is regulated by, the circumstances
 in which they are placed.   When  they are exposed, as in
 spring and summer, to the stimulus of heat and  light, all
 their  functions are  excited, waste and growth are acce-
 lerated,  and a  more  abundant supply of nourishment be-
 comes indispensable to  their  health  and 'existence;  and
 hence, in a dry soil incapable  of affording a copious  sup-
 ply of sap, they speedily wither and  die.  Exposed to cold,
 on  the other hand, and shaded  from the light, their vitality
 is impaired, and  the demand for nourishment greatly di-
 minished.   This is uniformly the  case in winter ; and many
 circumstances show that the change is really owing to the
 causes mentioned above, and not to anything inherent in
 the constitution of the vegetable itself.  In tropical climates,
 for  example, where heat, light, and moisture abound, ve-
getable  life is ever active, and  the  foliage ever thick and
 abundant; and even in our  own northern region we are
 able, by artificial  heat, so far to anticipate the natural order
of the seasons, as to obtain the ripened fruit of the vine in
 the very beginning of spring.  The whole system of forcing
vegetables and fruit, so generally resorted  to  for the early
supply of our markets, is, in truth,  founded on the princi-
ple  we are now discussing ; and, by the regulated applica-
tion of heat, light, and moisture,  we are able  to hasten or
to retard, to a very considerable extent, the ordinary stages
of vegetable life.   But to ensure  success in our operations,
we  must be careful to proportion the supply of nourishment
to the state of the plant at the time.   If, by the application
of heat, we have  stimulated it to  premature growth  and
foliage, we must at the same time  provide for it  an ade-
quate supply of food, otherwise  its activity  will  exhaust
itself, and indue* permature decay.   Hence the regular
watering which green-house plants require.  But if we have
                          3* 
SO       ANALOGY OF VEGETABLES AND ANIMALS.

retarded its progress and lowered its vitality by excluding
heat and light, the same copious nourishment will not only
be unnecessary, but will probably do harm by inducing re-
pletion and disease.
  In  vegetables the absorption  of food is thus  regulated
chiefly by the circumstances  of  heat, moisture, and  light
under which  the  plant is  placed,  and  by the  consequent
necessity which  exists at  the  time for a  larger or smaller
supply of nourishment to carry on the various processes of
vegetable life.  According to. this arrangement, nutrition is
always most  active when  the greatest expenditure of  ma-
terial is taking place.   When growth is  going on rapidly,
and the leaves are unfolding themselves, sap is sucked up
from the earth in  immense quantity ; but when these  pro-
cesses are completed as summer 'advances, and almost no
fresh materials are required, except for the consolidation of
the new growth and the supply of the loss by exhalation,
a much smaller amount of nourishment suffices, and the sap
no longer circulates in the same profusion.   In autumn,
again—when the fruit arrives at maturity, the leaves begin
to  drop  off, and the activity of vegetable life suffers abate-
ment—nutrition is reduced to its  lowest ebb ; and in this
state it  continues till the return  of spring stimulates every
organ to new action, and  once more  excites a demand for
an increased  supply.
  Nor is the same great principle, of supply requiring to be
proportioned to demand, less strikingly apparent in animals.
Wherever  growth is  proceeding rapidly, or the  animal is
undergoing much exertion and expenditure of  material, an
increased quantity of food is invariably required ; and, on
the other hand, where no new substance is forming, and
where, from bodily inactivity, little  loss is sustained, a com-
paratively small  supply will  suffice.   But  as  animals are
subjected to much more rapid and violent transitions  from
activity to inactivity than vegetables are—and  thus require
to pass more immediately from  one kind and  quantity of
nourishment  to another, in order to adapt their nutrition to
the ever-varying demands made  upon the  system—they
evidently stand in  need of some  provision to enforce atten-
tion when  nourishment is necessary, and to enable  them
always  to proportion  the  supply to the  real wants  of the
body.   Not  being, like vegetables, in  constant connexion
with their  aliment, they might suffer from  neglect if  they
did not  possess some contrivance to  warn them in  tima 
         THE APPETITES OF HUNGER AND THIRST.       31

 when to seek and in what quantity to consume it.   But in
 endowing animals with the sense of Appetite, or the sen-
 sations of  Hunger and Thirst generally included under it,
 the Creator  has guarded  effectually against  the inconve-
 nience, and given to them a guide in  every way sufficienl
 for the purpose.
   The  very  possession  of a stomach or receptacle, into
 which food sufficient for a shorter or longer period can bd
 introduced at one time, and which we have already remark
 ed  as  characterizing all animals from the lowest  to  the
 highest, almost necessarily implies the coexistence of some
 watchful monitor, such as appetite, to enforce attention to
 the wants of the system, with an earnestness which it shall
 not be  easy to resist.   If this were not  the  case in man,
 for example—if he  had no motive more  imperative than
 reason to oblige him to take food—he would be constantly
 liable, from indolence and  thoughtlessness, or the pressure
 of other occupations,  to  incur  the penalty  of starvation,
 without being previously  aware of his danger.   But  the
 Creator, with that beneficence which distinguishes all His
 works, has not only provided an effectual safeguard.in the
 sensations  of hunger and thirst, but, moreover, attached to
 their regulated indulgence a degree of pleasure which never
 fails to insure attention to their demands, and  which, in
highly civilized  communities, is apt  to  lead  to  excessive
gratification.   Such being the important charge committed
to the  appetites of hunger and  thirst, it will  be  proper  to
submit to the reader, before entering upon the consideration
of the more complicated process of digestion, a few remarks
on their nature and uses.
                    CHAPTER II.
         THE APPETITES OF HUNGER AND THIRST.
Hunger  and Thirst, what they are—Generally referred to the
  stomach and throat, but perceived by the brain—Proofs and illus-
  trations—Exciting causes of hunger—Common theories unsatis-
  factory—Hunger sympathetic of the state of the body as well as
  of the  stomach—Uses of appetite—Relation between waste  and
  appetite—Its practical importance—Consequences of overlooking
  it illustrated by analogy of the whole animal kingdom—Disease
  Irom acting in opposition to this relation—Effect of exercise on
  appetite explained—Diseased appetite—Thirst—Seat of Thirst-
  Circumstances in which it is most felt—Extraordinary effects of
  injection of water into the veins in cholera—Uses of thirst, and
  rules for gratifying it.
  In the preceding, chapter  I endeavoured to show, fist, 
32        SEAT OF THE SENSATION OF HUNGER.
 that nutrition is required only because waste and a deposi-
 tion of new particles  are continually going on, so that the
 body would speedily become exhausted if its constituent
 materials were  not renewed ;  secondly, that  the sense oi
 appetite is  given to animals for  the  express purpose of
 warning them when a fresh supply of  aliment is needed
 as, without some such monitor, they would be apt to neglect
 the demands of nature ;  and thirdly, that vegetables  have
 no  corresponding  sensation, simply because, from  their
 being  at all times in  communication with the soil,  their
 nutrition goes on continuously in proportion as it is neces-
 sary, and without requiring any prompter to put it in action
 at particular  times.
  If these principles be  correct, it follows  that, in  the
 healthy state, (and let the reader be once for all made aware
 that in the following pages the state of health is always
 inplied, except where it is^otherwise plainly expressed,) the
 dictates of appetite will  not be every day the same, but
 will  vary according to the  mode of life and wants of the
 system, and, when fairly consulted, will  be sufficient to
 direct us both at what time and in what quantity we ought to
 take in either solid or liquid sustenance.   But to make this
perfectly evident, a few general observations may be required.
  It is needless to waste words in  attempting to describe
 what hunger and thirst are :  every  one has felt them, and
 no one could understand them without such experience,
 any more than sweetness or sourness could be understood
 without tasting sweet or sour objects.   Their end is mani-
festly to proclaim that farther  nourishment is required for
 the support of the system ;  and our first business is, there-
fore, to explain  their  nature and seat, in so far at least as
a knowledge of these  may4be conducive to our welfare.
  The sensation of hunger is commonly referred to  the
stomach, and that of thirst to the upper part  of the throat
and back of the mouth ; and correctly enough to this extent,
that  a certain condition of the stomach and throat tends to
produce them.  But, in reality, the sensations themselves,
like  all other mental  affections and emotions, have their
 seat  in the  brain, to which a sense of the condition of the
 stomach is conveyed  through  the medium of the  nerves.
 In this respect  Appetite  resembles  the senses of Seeing,
 Hearing, and Feeling ;  and no greater difficulty attends the
 explanation of the one than of the others.   Thus, the cause
 which  excites the sensation of colour is certain rays  of light 
HUNGER A MENTAL SENSATION.           33
striking upon the nerve of the eye ;  and the cause which
excites the perception of sound is the atmospherical vibra-
tions striking upon the nerve of the ear ;  but the sensations
themselves take place in the brain, to which, as the organ
of the mind, the respective impressions are conveyed.  In
like manner, the cause which excites appetite is an impres-
sion  made on the nerves of the stomach ; but the feeling
itself is experienced in the brain, to which that impression
is conveyed.  Accordingly, just as in health no sound is
ever heard except when the external vibrating atmosphere
has actually impressed the ear, and no colour is perceived
unless an object be presented  to the eye—so is appetite
never felt, except where, from want of food, the stomach is
in that state which forms the proper stimulus to its nerves,
and where the communication between it and the brain is
left free and unobstructed.
   But as, in certain morbid states of the brain and nerves-
voices and sounds  are  heard, or colours and objects  are
seen, when no  external cause is present to  act upon  the
ear or the eye—so, in disease, a craving is often felt when
no real want of food exists, and where, consequently, indul-
gence in eating can be productive of nothing but mischief.
Such an  aberration is common in nervous and mental  dis-
eases, and not  unfrequently adds greatly to their  severity
and obstinacy.  In indolent unemployed persons, who spend
their days in meditating on their own feelings, thi3 craving
is very common, and, from being regarded  and  indulged
as if it were healthy  appetite, is productive of many dys-
peptic affections.*
   If the correctness of the  preceding explanation of the
sensation of hunger be thought to stand in need of confir-
mation, I would refer  to  the very conclusive experiments
by Brrchet, of  Lyons,  as setting the question entirely at
rest.   Brachet  starved a dog for twenty-four hours, till it
became  ravenously  hungry, after  which  he divided the
nerves which convey to the brain a  sense of the  condition
of the stomach.  He then placed food within its reach, but
the animal, which a moment before was impatient  to be fed,
 went and lay quietly down, as if hunger had never  been
 experienced.   When meat was brought close to it, it began
 to eat;  and, apparently from having no longer any con-
   * Dyspepsia (from the Greek words 6vg, dus, bad, and Tzeirru,
 pepto, I concoct) is synonymous with indigestion. 
34      NERVOUS COMMUNICATION BETWEEN THE
sciousness of the state of its stomach--whether it was full
or empty—it continued to eat till both  it and the  gullet
were inordinately distended.   In this, however, the  dog
was  evidently impelled solely by the gratification  of the
sense of taste ; for, on removing  the food at the beginning
of the  experiment to the distance of  even a few  inches, it
looked  on with indifference, and made no attempt either to
follow  the dish or to prevent its removal.*
  Precisely similar results ensued when the nervous sym-
pathy between the stomach and brain was arrested by the
administration of narcotics.   A dog suffering from hunger
turned  listlessly from its food when a few grains  of  opium
were introduced  into its stomach.   It  may be  said  that
3uch a result is  owing to the drug  being absorbed  and
carried to the brain  through  the ordinary medium  of the
circulation; but Brachet  has proved that this is not the
case, and that the influence is primarily exerted  upon the
nerves.  To establish this point, two dogs of the  same size
were selected.   In one the nerves of communication were
left untouched, and in the other they were divided.  Six
grains  of opium were then given to each at the  same mo-
ment.   The sound  dog began  immediately to feel the
effects of the opium and became stupid, while  the  other
continued lying at^the fire-side for a long time, without any
unusual appearance,  except a little difficulty of breathing.
In like manner, when the experiment was repeated with
that powerful poison nux vomica, upon two dogs similarly
circumstanced, the  sound one fell instantly  into convul-
sions,  while the other continued for a long time as if no-
thing had happened.
   These results demonstrate, beyond  the  possibility of
doubt, the necessity of a free nervous communication be-
tween  the stomach and brain, for  enabling us to experience
the sensation of hunger.  The connexion between the two
organs is, indeed, more widely recognised in practice than
it is in theory;  for it  is a very common custom with the
 Turks to use opium for abating  the pangs of hunger when
 food is not to be had, and sailors habitually use tobacco
 for the same purpose.   Both substances act exclusively on
 the nervous system.
   The relation  thus shown to subsist between the stomach
   * Brachet, Recherches Experimental sur les Fonctions  du
 Systgme Nerveux Ganglionaire, chap. iii. Paris edition. 
  STOMACH AND BRAIN NECESSARY FOR ITS PERCEPTION. 35

and  the brain, enables us in some measure to understand
the influence which  strong  mental emotions  and  earnest
intellectual occupation exert over the appetite.   A man in
perfect health, sitting down to table with an excellent  ap-
petite, receives a letter announcing an unexpected calamity,
and instantly turns away with loathing from the food which,
a moment before, he was prepared to eat with relish; while
another, who, under  the fear of some misfortune, comes to
table indifferent about food, will eat with great zest on  his
" mind being relieved," as the phrase goes, by the receipt
of pleasing intelligence.  Excessive and absorbing emotion,
even of a joyful kind, has the same effect.  Captain Back
tells us, in the interesting narrative of his last journey, that
when he first heard of Captain Ross's return, " the thought
of so wonderful a preservation overpowered, for a time,  the
common occurrences of life.   We had  but just sat down
to breakfast, but our  appetite was gone,  and the day passed
in a feverish state of  excitement." (P. 245 )  In such cases
no one will imagine  that the external cause destroys  ap-
petite otherwise than through the  medium of the brain.
Occasionally, indeed,  the aversion to  food amounts to a
feeling of loathing and disgust, and even induces sickness
and vomiting—a result which depends so entirely on  the
state of the brain, that it is  often excited by mechanical
injuries of that organ.
   The analogy between the external senses and the appe-
tite is in various respects very close.  If we are wrapped in
study, or  intent on  any scheme,  we become insensible to
impressions made on the ear or eye.  A clock may strike,
or a person enter the room, without our being aware of
either event.   The  same is the  case with the desire for
food.  If the mind  is deeply engaged, the wants of  the
system are unperceived  and unattended  to—as was well
exemplified in the instance of Sir Isaac Newton, who, from
seeing the bones of a chicken lying before him, fancied that
he had already dined, whereas,  in reality, he had  eaten
nothing for many hours.   Herodotus ascribes so  much effi-
cacy to mental occupation in deadening the sense of hun-
ger,  that  he speaks of the inhabitants of Lydia having
successfully had recourse to gaming as a partial substitute
 for  food, during a famine of many years continuance.   In
 this account there is, of course, gross exaggeration ;  but it
 illustrates sufficiently well the principle under discussion. 
36        CAUSE OF THE SENSATION OF HUNGER.
   Many attempts have been made, but without much suc-
 cess,  to determine  what  the peculiar condition of  the
 stomach is  which excites in the mind the  sensation of
 hunger.  For a long time  it was imagined  that the pre-
 sence of gastric or stomach juice, irritating the nerves of
 the  mucous  membrane, was the exciting cause ; but it was
 at last  ascertained that, after the digestion of a  meal is
 completed, and the chyme  has passed into  the intestine,
 the  gastric  juice ceases to be secreted  till after a fresh
 supply of food has been taken in.*  It was next supposed
 that the mere  emptiness of the stomach was sufficient to
 excite hunger, and that the sensation arose partly from the
 opposite sides rubbing against each other.  But this theory
 is equally untenable ;  for  the stomach generally contains  a
 sufficient quantity of air to prevent the actual contact of its
 sides, and, moreover, it may  be entirely void of food, and yet
 no appetite be felt.   It may be laid down, indeed, as a ge-
 neral rule, that an  interval of rest must follow the termina-
 tion of digestion before the  stomach becomes fit to resume
 its functions, or appetite is experienced in  any degree of
 intensity ; and the length  of time required for this  purpose
 varies very much,  according to the mode of life and to the
 extent of waste going on in  the system.  In many diseases,
 too, the stomach  remains empty  for  days in succession,
 without any corresponding excitation of hunger.  Even in
 healthy  sedentary people, whose expenditure of bodily sub-
 stance is small, real  appetite is not felt till long after the
• stomach is empty, and hence one of  their most common
 complaints is the want of appetite.
   Dr. Beaumont suggests a distended state  of  the vessels
 which secrete  the gastric  juice as  the exciting cause of
 hunger, and thinks that this view is strengthened by the
 rapidity with which the juice is poined out after  a short
 fast—a  rapidity, he says,  which  cannot be  accounted for
 except by supposing the juice to have existed  ready made
 in the vessels or follicles by which it is secreted.  But this
   * It is  difficult, as in the above sentence, to avoid occasionally
 using expressions and referring to processes which have not pre-
 viously been explained ; but it would only lead to confusion and
 unnecessary repetition to stop at every page and introduce explana-
 tions, which, after all, the reader would scarcely understand on ac-
 count of their brevity.  In the present instance, therefore, where I
 allude to the process of digestion, it is better to refer the reader to
 the outline given at the beginning of Chanter IV., than to distract
 his attention by introducing it also here. 
        SYMPATHY BETWEEN SYSTEM AND STOMACH.     37

 theory is not more  satisfactory than the rest, for  in the
 sudden flow of saliva into the mouth of a hungry man on
 the unexpected appearance of savoury viands, we have an
 instance  of equally rapid  secretion where there was evi-
 dently no  storing up beforehand.   Besides,  there  is an
 obvious  relation  between appetite  and the wants  of the
 system, which is not always taken sufficiently into account,
 and which is, nevertheless, too important to be overlooked.
  If the body be very actively exercised, and  a good deal
 of waste be  effected by perspiration and exhalation from
 the lungs, the appetite becomes keener, and more urgent
 for  immediate gratification; and if it is indulged, we eat
 with a relish  unknown on other occasions, and  afterward
 experience a sensation of bien-itre or internal comfort per-
 vading the frame, as if every individual  part of the body
 were imbued with a feeling of contentment and  satisfaction,
 the very  opposite of the restless discomfort and depression
 which come  upon us, and extend over the whole system,
 when appetite is disappointed.  An amusing  example of
 the principle here inculcated is to be found in  the Corres-
pondence Inedite  de Madame du Deffand,* where she de-
 scribes her friend Madame de Pequigni  as  an insatiable,
 bustling  little woman who consumes two hours every day
 in devouring her  dinner, and "eats like a wolf."   But,
 then, remarks Madame du Deffand, by way of explanation,
 " II est vrai qu'elle fait un exercice enrage."
  There is, in short, an obvious and active sympathy be-
 tween  the condition and bearing of the stomach and those
 of every part of the animal  frame—in virtue of which.
 hunger is felt very keenly when the general system  stands
 in urgent need of repair, and  very moderately when  no
 waste has been suffered.   This principle is strikingly illus-
 trated during recovery from a severe illness.   " In conva-
 lescence  from an acute disease,"  as is well remarked by
 Brachet,  " the stomach digests vigorously, and yet the in-
 dividual  is always hungry.  This happens because  all the
 wasted organs and tissues demand the means of repair, and
 demand them from the stomach, which has  the charge of
 sending them ;  and, therefore, they keep up in it the con-
 tinual sensation of want, which, however, is, in this  case,
 only sympathetic  of the state of the body."t  In alluding
  * Vol. iii., p. 40. Paris, 1309.
  t Brachet, Recherches Experimentales sur les Fonctions du Syl
 tome Nerveux Ganglionaire, p. 181.
                          4 
 38     RELATION BETWEEN WASTE *ND APPETITE.

 to this  subject, Blaine observes, that " Hunger and thirst
 can only be satisfactorily explained by  considering them as
 properties  in  the stomach by which it sympathizes with
 the wants of the constitution ;  and  hence it is that food
 taken in invigorates, even  before  it can  be  digested."*
 Hence also the prostration of strength that is felt when the
 stomach has been for some time empty.
  This  sympathy is sometimes  singularly manifest even in
 disease.  In some  cases of affection of  the  mesenteric
 glands,  for example, where stomachic digestion remains for
 a time pretty healthy, and the general system suffers chiefly
 from the want of nourishment caused by the passage of the
 chyle into the blood being obstructed, the appetite continues
as keen and often keener than before ; because the system,
being in want of nourishment, and the stomach healthy,  all
its natural causes continue to act  as before ; and  accord-
ingly, when  food is taken, it is digested there as usual, but
 the chyle which is formed from it in the  intestine can  no
longer be transmitted  through  the swollen glands  in  its
usual healthy manner, to be converted  into nutritive blood
in the lungsr,  and the  system thus failing to receive the
required supply, recommences its  cravings almost as soon
 as if no food had been obtained.   When  the  disease has
advanced a certain length, however, fever  springs up, and
destroys both appetite and digestion.
  The effects of exercise also show very clearly  the con-
nexion between appetite and the state of  the system.   If
 we merely  saunter out for a given  time everyday, without
 being actively  enough engaged  to quicken the  circulation
 and induce increased  exhalation from the skin and lungs,
 we come in  with  scarcely any change of feeling or  condi-
 tion ; whereas, if we exert ourselves sufficiently to give a
 general  impetus to the circulation, and bring out moderate
perspiration, but without inducing  fatigue, we  feel a light-
 ness and energy of a very pleasurable description, and ge-
 nerally  accompanied by a strong  desire for food.   Hence
 the keen relish  with which the fox-hunter sits  down  to
 table  after a successful chase.
  This  intimate communion between the state of the sys-
 tem  and that  of the stomach is  a beautiful provision  of
 Nature, and is one of the causes of the  ready sympathy
 which has often  been  remarked as  existing between the
  • Blaine's Outlines of the Veterinary Art, third edition, p. 273 
        RELATION BETWEEN WASTE AND APPETITE.     39

stomach and all the other organs—in other words, of the
readiness with which they accompany it in its departure
from health, and the corresponding aptitude of their disor-
ders to produce derangement of the digestive function.  Ap-
parently for the purpose, among others, of  thus intimately
connecting the stomach with the rest of the system, it is
supplied with a profusion  of nervous filaments of every
kind,  which form a closely-interwoven nervous network  in
its immediate neighbourhood, and the abundance of which
accounts for the severe and often suddenly fatal result of
a heavy blow on the pit of  the stomach.
  Without pretending to determine what the precise con-
dition of the nerves of the stomach  is, which, when con-
veyed  to the brain,  excites the sensation  of appetite, I
think  it sufficient for every practical purpose if we keep
in mind, that the co-operation of the nervous system is ne-
cessary for the production of appetite, and  that there is a
direct sympathy between the stomach and  the rest of the
body,  by means of which the stimulus of hunger becomes
unusually urgent  where the bodily waste has been great,
although a comparatively short time  has elapsed since the
preceding meal.
  Appetite, then, being given for the express purpose  of
warning us when a supply of food is necessary, it follows
that its call will be experienced in  the highest intensity
when  waste and growth—or, in other words, the operations
which demand supplies of fresh materials—are most ac-
tive ;  and in the lowest intensity when, from indolence ant»
the  cessation of growth, the demand is least.  In youth,
accordingly, when bodily activity is very great, and a libe-
ral supply of nourishment is required both  to repair waste
and to  carry on growth, the appetite  is keener and less
discriminating than  at any other period of life, and, what
is worthy of remark, as another admirable instance of adap-
tation, digestion is proportionally vigorous  and rapid, and
abstinence  is borne with great difficulty ; whereas, in ma-
ture age, when growth is finished and  the mode of life more
sedentary,  the same abundance of aliment is  no longer
needed, the appetite becomes less keen and more select  in
its choice,  and digestion loses something of the resistless
power which generally distinguishes it in early youth.
Articles of food which were once  digested with ease, are
now burdensome to the stomach, and, if not altogether re- 
40       EVILS FROM NEGLECTING THE RELATION
 jected, are disposed of with a degree of labour and  diffi-
 culty that was formerly unknown.   Abstinence also is now
 more easily supported.
   When, however, the mode  of life in mature age is ac-
 tive and laborious, and the waste matter thrown out of the
 system is consequently considerable, the appetite for food
 and the power of digesting it are correspondingly strong ;
 for in general it  is onlv when the mode of life is indolent
 and inactive, and the  waste consequently small, that the
 appetite  and digestion are  weak.  So natural, indeed,  is
 the connexion between the two conditions, that exercise  is
 proverbially the  first  thing we think  of  recommending  to
 improve  the appetite and the tone of the digestive  organs,
 when these are  observed  to be impaired ; and where po-
 sitive disease  does  not exist, no other remedy is  half so
 effectual.  But,  as already noticed, exercise  to be  benefi-
 cial must be of a description  calculated to increase the
 activity of  the  secretions and excretions;  otherwise  it
 cannot place the system in a condition to require an abun-
 dant supply or excite vigorous  digestion.
   It is' highly important, to notice this natural relation
 between waste and appetite, and between appetite  and di-
 gestion ; because, if it be real, appetite must b'e the safest
 guide we can follow in determining when and how much
 we ought to eat.  It is true that in disease, and amid the
 factitious calls and wants  of civilized life, its suggestions
 are often perverted, and that hence we may  err in  blindly
 following everything which  assumes its semblance.  The
 conclusion  to be drawn  from  this, however, is,  not that
 the sense of hunger  will, if trusted to, generally mislead
us, but only that we must learn to distinguish its true dic-
 tates before we  can implicitly rely on its guidance.  If,
 when fairly consulted, its dictates  are found to  be  erro-
neous,  it will constitute the only known instance  where
the Creator has failed in the attempt to fulfil his own de-
 sign—an assumption  not  only repugnant alike to  feeling
 and to  reason, but, in fact, altogether gratuitous.  For the
 apparent discrepancies which  occasionally present  them-
 selves between the  wants of the system and the  dictates
of appetite, are easily explicable on  the more solid ground
of our  own ignorance and  inattention.
  Many practical errors arise from overlooking the  rela-
 tion which nutrition ought  to bear to waste  and  growth. 
BETWEEN WASTE AND APPETITE.          41
 Thus, it is no uncommon  thing for young men who  have
 experienced all the pleasures of a keen appetite and  easy
 digestion when growing rapidly or leading an  active life,
 to induce severe and  protracted indigestion, by continuing,
 from mere habit, to eat an equal quantity of  food either
 when growth is finished and the system no longer requires
 the  same  extensive  supply, or after  a complete change
 from active to sedentary habits has greatly diminished that
 waste which alone renders food necessary.  This is, in fact,
 one  of the  chief sources of  the  troublesome  dvspeptic
 complaints often  met  with among the youthful inhabitants
 of our larger  cities and colleges,  and ought not to be lost
 sight of in the physical education of the young.
   The  error, however, is  unhappily not confined to the
 young, but extends generally to all whose pursuits are of a
 sedentary nature.   There are numerous persons, especially
 in towns  and among  females, who, having their  time and
 employments  entirely  at their  own disposal, carefully avoid
 everything which requires an effort of  mind or body, and
 pass  their lives in a state of inaction entirely incompatible
 with the healthy performance of the various animal func-
 tions.  Having no bodily exertion to excite waste, promote
 circulation,  or stimulate nutrition, they experience  little
 keenness of appetite,  have weak powers of digestion, and
 require but a limited supply of food.  If, while inactive and
 expending little, such  persons  could be contented to-follow
 nature so far as not to provoke appetite by stimulants and
 cookery, and  to eat and drink only in proportion to the
 wants of the  system,  fliey would  fare comparatively well.
 But having no imperative occupation and no enjoyment from
 active and useful exertion, their time hangs heavily on their
 hands, and they are apt to have recourse to eating as the
 only  avenue to pleasure still open to them ;  and, forgetful
or ignorant of the relation  subsisting between  waste  and
nutrition, they endeavour to renew,  in  the present indul-
gence of appetite, the  real enjoyment which its legitimate
gratification afforded under different circumstances.  Pur-
suing the pleasures of the table with the same ardour as
before, they  eat  and   drink  freely and abundantly, and,
 instead of trying to acquire a healthy desire for food  and
 increased  powers  of digestion by exercise, they resort to
 tonics, spices, wine, and other stimuli, which certainly excite
 for the moment, but eventually aggravate the mischief by
                          4* 
 42    EVILS FROM NEGLECTING THE RELATION, ETC.

 obscuring its progress and extent.  The natural  result of
 this mode of proceeding is, that the stomach becomes op-
 pressed by excess of exertion—healthy appetite gives way,
 and morbid craving takes its place—sickness, headache, and
 bilious attacks become frequent—the bowels are habitually
 disordered, the feet cold, and the circulation irregular—and
 a state of bodily weakness and mental irritability is induced,
 which constitutes a heavy penalty for the previous  indul-
 gence.   So far, however, is the true cause of  all these
 phenomena from being perceived even then, that a cure  is
 sought, not in abetter regulated diet and regimen, but from
 bitters to strengthen the  stomach, laxatives to carry off the
 redundant materials  from  the system, wine  to  overcome
 the sense of sinking, and heavy lunches to satisfy the mor-
 bid craving which they only silence for a little.    Some, of
 course, suffer  in a greater and others in  a  less degree, ac-
 cording  to peculiarities  of constitution,  mode of life, and
 extent of indulgence ; but daily experience will testify that,
 in its main features, the foregoing description is  not over-
 charged, and that victims to such dietetic errors are to be
 met with in every class of society.
   The fact of Nature having meant the inactive and indo-
 lent to eat and drink  less than  the busy and  laborious, is
 established not only by the diminished  appetite and impair-
 ed digestion of human beings who lead a sedentary life, as
 contrasted with the keen relish and rapid digestion usually
 attendant on active exertion in the open air, but on a yet
 broader scale by the analogy of all other animals.  In no-
 ticing this relation, Dr. Roget remarks, that " the greater
the energy with which the more peculiarly animal functions
of sensation and muscular action are exercised, the greater
must be the demand for nourishment, in order to supply the
expenditure of vital force created by these exertions.  Com-
pared with  the torpid  and sluggish reptile, the  active and
vivacious bird or quadruped requires and consumes a much
larger quantity of nutriment.   The tortoise, the turtle, the
toad,  the frog, and  the chameleon  will, indeed, live for
months without taking any food."  " The  rapidity of de-
velopement,"  he continues, " has also great  influence on
the quantity of food which an animal requires.   Thus the
 caterpillar, which grows very quickly, and must repeatedly
 throw off its  integuments, during its continuance  in the
 larva state, consumes a vast quantity of food compared with 
        FULL DIET INCOMPATIBLE WITH INACTION.     43

the size of its body ;  and hence we find it provided with a
digestive  apparatus of considerable size."*   Hence, too,
the greater demand  for food in infancy  and youth when
growth and activity are both at their height.
  In thus insisting on regular bodily and mental activity as
indispensable to the enjoyment of a good appetite and sound
digestion, the attentive reader will not, I trust, be disposed
to accuse me of  inconsistency because, when  treating of
muscular  exercise in  the former volume,! I explained  the
bad effects, and inculcated the impropriety, of indulging in
any considerable exertion immediately before or after a full
meal.  It is true, as there mentioned, that exercise, either
in excess or at an improper  time, impairs the tone of  the
stomach; but it is not  on that account the less true that
bodily exertion, when seasonably  and properly practised, is
the best promoter of appetite and digestion which we pos-
sess ;  and it is only under the latter conditions that I now
speak of it as beneficial and even indispensable to health.
   In  a work like the present, it is obviously  impossible to
fence  round every general proposition with the numerous
limitations which an unusual combination of circumstances,
or a  departure from  the state of health, might demand.
And,  even if possible, it would not be necessary, as the laws
of exercise have  been so fully explained in the volume
alluded to, that their  rediscussion here  would unavoidably
involve much repetition from  its pages.  At the same time,
some  warning remark may be required to  prevent any risk
of misconception, as it might otherwise be  plausibly argued,
for example, that  there can be no such relation as I have
alleged between waste and appetite, because a European
perspiring under a tropical sun incurs great waste, and yet
loses  both appetite and digestive power.   To render this a
valid exception, it must be shown that the European is in-
tended by Nature to live in a tropical climate, and that  the
diet to which he accustoms himself is  that sanctioned by
experience as  the best adapted for his constitution ;  be-
cause, if neither is the case, his condition  under such influ-
ences must necessarily be more or less closely allied to the
state of disease, and therefore beyond the sphere to which
alone my remarks are  meant to apply.  But even in that in-
stance there is less contradiction than might  be imagined,
  * Roget's Bridgewater Treatise on Animal and Vegetable Phy-
siology, vol. ii., p. 112.
  t Principles of Physiology, &c., chapters IV. and V. 
44      FULL DIET INCOMPATIBLE WITH INACTION.
for the waste of the system, being chiefly fluid, excites—
not appetite, but its kindred sensation—thirst, to repair the
loss by an unusual demand for refreshing liquids.
   So  true is it that the Creator  has  established a relation
between action and nutrition, that when we attempt for any
length of time to combine a full and nutritious diet with
systematic  inactivity,  the derangement of health  which
generally ensues gives ample proof of the futility of  strug-
gling' against His laws.   Individuals, indeed, may be met
with,  who,  from some peculiarity of constitution,  suffer
less than the  generality of mankind from  making the ex-
periment ; but even those among them  who escape  best,
generally owe their safety to the constant use of medicine,
or to a natural excess in some of the excretory functions,
such as perspiration or the urinary or alvine discharges, by
means of which the system is relieved much in the same
way as by active exercise ; and hence the remark made by
Hippocrates, that severe perspirations arising during sleep
without any other apparent cause, are a sure sign that too
much nourishment  is made use  of.  In others, again, the
day of reckoning is  merely delayed, and there is habitually
present a state of repletion, which clogs  the bodily func-
tions, and may lead to  sudden death by some acute disease
wher  the individual is apparently in  the highest health.  I
am acquainted with several individuals of this description,
who, in the  absence of all bodily exercise, are accustomed
to live very fully—to eat in the morning a hearty breakfast,
with eggs, fish, or flesh—a good solid luncheon, with wine
or malt liquor, in the forenoon—a most substantial dinner,
with dessert and several glasses of wine, and afterward tea
and wine and water, in the evening—and who, nevertheless,
enjoy tolerably good digestion.  But this advantage is gene-
rally only temporary, and even when permanent can scarcely
be considered as a boon ; because it is gained at the  direct
expense either of a very full habit of body and  an unusual
liability to abdominal congestion  and  all its attendant evils,
or of frequent and profuse perspirations, and severe attacks
of bowel complaint, endangering life  ; so that, strictly con-
sidered, such cases are no exceptions to the general  rule.
   It is, then, no  idle whim of the physician to insist on
active  exercise  as  the  best promoter of appetite  and di-
gestion.  Exercise is, in fact, the condition"without which
exhalation and excretion  cannot go  on  sufficiently fast to 
DEFICIENT DIET AND EXCESS OF LABOUR.       45
  clear the system of materials previously taken in; and where
  no waste is incurred, no need of a fresh supply, and, conse-
, quently, in a healthy state of the system, no natural appetite,
  can exist.   It is, therefore, not less  unreasonable than vain
  for any one to  insist on possessing, at the same time, the
  incompatible enjoyments of luxurious indolence and a vigo-
  rous appetite—sound digestionof a hearty meal, and general
  health of  body  ; and no one who is aware of the  relation
  subsisting between  waste and appetite, can fail to perceive
  the fact, and  to wonder at  the contrary notion having ever
  been entertained.
    Among the  operative  part of the community we meet
  with innumerable examples of an opposite condition of the
  system, where,  from excess of labour, a greater expenditure
  of energy and substance takes place than what their defi-
  cient  diet  is able to repair.  It is true that the disproportion
  is generally not sufficient to cause that immediate wasting
  which accompanies actual starvation, but  its effects are,
  nevertheless, very palpably manifest in the depressed buoy-
  ancy, early old age, and  shorter  lives  of the labouring
  classes.   Few, indeed, of those who are  habitually sub-
  jected to  considerable and continued exertion survive their
  forty-fifth  or fiftieth year.  Exhausted  at  length by the
  constant recurrence of their daily task and imperfect nour-
  ishment, they die of premature decay  long before attaining
  the natural limit of  human existence.
    In those states of the system, again, such as fever, during
  the continuance of which most of the secretions are vitiated,
  and that of the gastric juice often entirely suppressed, and
  where food would consequently  be hurtful  rather  than
  advantageous, appetite is  scarcely felt, and  loathing often
  occupies its place.   But the moment that, by the diminu-
  tion of the disease,  the secretions and exhalations begin to
  return to their healthy state,  and nutrition is resumed,
  appetite begins to  be  again felt, and by and by becomes
  abundantly vigorous, in order to restore  the system to its
  former state.  The utmost caution, however, is still required
  in its gratification, as a  premature indulgence is almost
  certain again to stop the secretions and to produce a relapse.
  Ignorance of this principle among the community at large,
  and the consequent error of giving food when there  is no
  demand for it, and no gastric  juice  to digest it, often do
  more to defeat the  best laid plan of cure than the severity 
46        INFLUENCE OF DISEASE ON APPETITE.

of the disease  itself.  The sick  man's friends, in their
anxiety to support his strength, too frequently turn a deaf
ear to every caution which is suggested, arid  stealthily
administer  sustenance when the  system docs not require
it, and when it  serves  only to aggravate  the  danger and
increase the weakness of the patient.  Since the first publi-
cation of the preceding passage, I have  seen a striking
example of its truth.  The patient was gradually recovering
from inflammation of the chest, for the cure of which low
diet was for a time indispensable.   By way of supporting
the diminished strength, the relations began to give, prema-
turely and  clandestinely, about double the quantity of food
which was prescribed.  For twenty-four hours an increase
of strength was felt accordingly ;  but very soon it passed
into febrile excitement with a quick  pulse and increased
weakness.  A dangerous  relapse followed,  and its  cause
was then found out.  Abstinence was again enforced, and
tartar  emetic given to  excite  nausea.   To the surprise of
the very injudicious friends, the  excitement began  almost
immediately to  subside and the strength to improve where
they had just seen it fast giving way under a full diet.
  Appetite, it ought to be observed, may, like other sensa-
tions, be educated or trained to considerable deviations from
the ordinary standard of quantity and quality—and this ob-
viously for the purpose of enabling man to live in different
climates and under different circumstances, and avoid being
fixed down to one spot  and to one occupation.  In civilized
life, however, we are accustomed to take undue advantage
of this capability, by training the appetite to desire a greater
quantity of food'than what the  wants of the system require,
and stimulating its cravings by a system of cookery little
in harmony with  the  intentions of Nature.   But  this is
evidently an abuse, and no argument whatever against the
sufficiency  of its natural indications to lead us right.
  But the most common source of  the errors into which we
are apt to fall in taking appetite as our only guide, is  un-
questionably the confounding of appetite with taste, and con-
tinuing to eat for the gratification  of the latter long after
the former is satisfied ; just as the dog already mentioned
ate till the oesophagus was distended, although it did not
experience the slightest sensation of hunger.*  In fact, the
whole science of  a skilful cook is  expended in producing
                       * See p. 34. 
APPETITE A FAIR INDICATION OF WANT.       47
this  willing mistake  on our part; and  he is considered
decidedly the best artiste whose dishes shall recomend them-
selves most irresistibly to the callous palate of the gour-
mand, and  excite on  it such a sensation as shall  at  least
remind him of the enviable excellence of a natural appetite.
If we were willing to limit the office  of taste  to its proper
sphere and  to cease eating when appetite expressed content,
indigestion would be  a much rarer occurrence in civilized
communities than it is observed to be.
  Viewed, then, in its proper light, appetite is to tie regard-
ed as kindly implanted in our nature for the express end of
proportioning  the supply of nourishment to the wants  of
the system ; and if ever it misleads us, the fault is not in its
unfitness for its object, but  in the artificial training which
it receives  at our own hands,  and in our own habitual ne-
glect of  its dictates.   When we attend  to its real indica-
tions, we eat  moderately, and at such intervals of time as
the previous exercise and other circumstances render neces-
sary ;  and  in so doing we reap a reward in the daily enjoy-
ment of the  pleasure  which  attends the gratification of
healthy appetite.  But if we err, either  by neglecting the
timely warning which it gives, or by  eating more than the
system requires, mischief is sure to follow.   In the former
case  waste continues to  make  progress  till the body be-
comes exhausted; and in almost exact proportion do the
cravings of appetite  become  more and  more intense,  till
they pass into those  of uncontrollable hunger, which over-
throws all  obstacles, and  seeks  gratification at the risk of
life itself.   In the latter case indigestion, gloomy depres-
sion, and repletion with its concomitant evils, make  their
appearance, and either imbitter or cut short existence.
  Mischief sometimes arises also  from  people not being
sufficiently aware that, in common with other sensations,
appetite  may be so far deranged by disease as to give very
incorrect and  unnatural indications.   It often happens, for
example, that a patient shivers and complains of cold, when
we know by the thermometer that  the heat of the  skin is
really above instead of below the natural standard.  In like
manner, in some  morbid states of the nervous  system a
craving  is  often felt  which impels the patient to eat, but
which is not true hunger ; and here food, if taken, is digest-
ed with  great difficulty.  Occasionally, on the other hand,
no desire for food is  experienced when the  system really 
 48 APPETITE DISORDERED BY DISEASE--THIRST--ITS SEAT.

 needs it, and when it would be digested with ease if intro-
 duced into the stomach.   Esquirol alludes  to cases  of
 this description,  and I have met with similar  examples.
 Voison also mentions that, in the Hospital of Incurables,
 in Paris, there are some idiots so low in the scale of intel-
 ligence, as to make no attempt to take the food which is
 placed before  them, although they eat and  digest readily
 when fed by others.  Sometimes, again, appetite is  de-
 praved in quality, and the patient desiderates the most nause-
 ous and refiulsive kinds of food, such as earth, chalk, coals,
 or excrement.   There are states, too, in which the appetite
 is prodigiously increased,  and the patient consumes  incre-
 dible  quantities of food—which, however, are very imper-
 fectly digested.  Charles Domery,  for instance,  when a
 French prisoner, at Liverpool, consumed, in  one day, four
 pounds of cow's udder and ten pounds of raw beef, with
 two pounds of tallow  candles  and five bottles of porter;
 and, although allowed the daily rations of ten men, he was
 still not satisfied.  Baron Percy speaks of another man,
 who ate twenty-four pounds of~beef in as many hours, and
 thought nothing of swallowing a dinner prepared for fifteen
 German boors.   I once attended a patient who was afflict-
 ed with a similar  inordinate craving, and  whose only plea-
 sure was  in eating.  In  such  cases no restraint, except
 actual coercion, is sufficient to prevent indulgence ; but the
craving itself is as  much the product of disease as  the
shivering in the beginning of fever, and  can no more be
removed by reasoning than the sensation of cold can be re-
moved by telling a patient  that his skin is  thermometrically
warm.  But these, being cases of disease, do not in any
degree militate against the accuracy of the exposition above
given  of the healthy uses of appetite.
  The general considerations which I have just submitted
to the reader on the subject of appetite for food, apply so
closely to the sensation of Thirst, that to enter into any
detail concerning the latter would be little else  but  to be
guilty of repetition.  I shall, therefore, limit myself to a
very few remarks.
   Thirst is generally said to have its seat in the back of the
mouth and throat; but  the condition of these parts is mere-
ly a local accompaniment  of a want experienced by the
whole frame, and perceived by the nervous system.   Local
 applications, accordingly, go but a short way in giving re- 
          THIRST VARIES ACCORDING TO FOOD.        49

lief, while the introduction of fluids by any other channel
—by immersion in a  bath, by injection into the veins, or
through an external opening into the stomach—is sufficient
to quench thirst without the liquid ever touching the throat.
The affection of that  part, therefore, is merely a result of
the state of the system, and not itself the cause of thirst.
  Thirst, or a desire for liquids, is experienced in its great-
est intensity when the secretion and exhalation of the ani-
mal fluids is most active ;  and it is consequently most
urgent in summer, in warm climates, and in persons engaged
in severe exertion, particularly if exposed at the same time
to a heated  atmosphere.  Blacksmiths, glass-blowers,  en-
gineers,  and others, whose employment exposes them to
the heat of furnaces, and in whom perspiration is excessive,
are accordingly almost constantly under the influence  of
thirst;  whereas those who are  employed in professions re-
quiring only moderate exertion in a temperate atmosphere,
and in whom the fluid secretions are very moderate, rarely
experience  the  sensation in  an urgent degree.   For  the
same reason great loss of blood induces excessive and  in-
tolerable thirst; and  hence,  in the battle-field,  the  gene-
rous self-denial of him who passed the cup to his wounded
neighbour, without stopping even to moisten his own lips,
cannot be too highly appreciated.
   Thirst varies in intensity also according to the nature
of the food.  If the diet be hot and stimulating, such as
results from a free admixture of spices or salt, the desire
for drink is  greatly increased.   The  same  thing happens
if the food be of a dry and solid nature.  The purpose of
the increased thirst in the former circumstances is mani-
festly to dilute  and diminish  the excess of stimulant, and
thereby  prevent the  injury which it would otherwise in-
flict.   The  same principle explains the thirst experienced
by those who drink too much wine.   In instances of thi3
kind I have  heard great thirst in the evening and during the
night complained of  as habitual, without the  person even
suspecting that it  was owing to the wine ;  and yet, on ab-
staining from the  latter, the thirst very soon disappeared.
   Continued thirst, it is well known, is much more into-
lerable than continued hunger.   The mass of circulating
fluid in the  body is very great,  and, as the various  excre-
tions  consist chiefly of fluid matter, it necessarily happens
that, when  these have been eliminated for a considerable
                          5 
50   THIRST MORE URGENT THAN HUNGER—ITS USES.

time without any liquid  being received  into the system,
the proportion of solid matter  in the body becomes unduly
large.   The blood, consequently,  becomes  thicker and
changed in quality, and much more irritating than it is in its
natural state.  The craving of thirst is thus generally ren-
dered more urgent and overpowering than that of hunger.
  In Asiatic Cholera the watery portion of the blood, on
which  its  fluidity depends, is drained off with frightful
rapidity ;  and  the result  is, in the first place, an  almost
complete  stoppage of the circulation, and, in the  second,
a constant craving for drink to supply the place of the lost
serum, which  consists chiefly of water holding some of
the alkaline salts in solution.  This circumstance explains
in some degree the extraordinary effects which have been
produced, even in the worst  stages of the disease when
life seemed almost extinct, by injecting large quantities of
saline solutions into the veins.  Patients apparently on the
verge of existence, cold, pulseless, and inanimate, have, in
the course of a  few minutes,  been  enabled by this means
to sit up in bed, and  to  exhibit all  the  signs  of restored
strength and health.  The effect, it  is true, was  rarely
permanent, but for the time it was so wonderful  as often
to look like restoration from the dead.*
  Fluids taken into  the  stomach, it is proper to observe,
are not subjected to the slow  process of digestion, but are
absorbed directly into the system ;  so that, when we take
a moderate draught, the whole  of  it is imbibed from the
stomach in a very few  minutes.  Keeping in view this
fact, and the above striking illustration of the influence of
the condition of the blood upon  the body at large, it be-
comes easy to conceive why,  in a state of exhaustion from
abstinence, drink should be more speedily restorative and
refreshing than food.
  Thirst, like appetite for food, is intended  to direct us
when and in what quantity we ought to drink ; and so long
as we lead a life of ordinary  health and activity, and con-
fine ourselves to the fluids with which Nature provides us,
there is little chance of our going far  wrong  by listening
to its calls.  But when we become indolent and dyspeptic,
or resort to the use of fermented and stimulating liquors,
which excite a thirst not recognised by Nature, the prin-
  » For some very curious details on this subject, the reader mav
 eoniult the last edition of Dr. Mackintosh's Practice of Physic. 
MASTICATION.
51
ciple  ceases  to  apply.  As present,  however, my obser-
vations refer entirely to such simple drinks as water, and
to the state of health ;  and I shall touch upon other liquids
when treating of diet in a subsequent part of  the volume.
Many persons, without experiencing any real thirst, habitu-
ally indulge  in  potations of water or beer at  all hours of
the day, and  to an extraordinary extent, and feel unhappy
when suddenly restricted in  the indulgence.   But this
temporary discomfort ought not to be considered as indi-
cating that these potations are really necessary, because
the same result happens in the analogous instances of smok-
ing or snuffing.   All three are abuses and perversions of
Nature; and the uneasiness attending the sudden cessation
of the beer or water drinking  is no more a proof of either
fluid being required, than that consequent on  giving  up
cigar  smoking is an  indication that Nature designed  the
lungs for the reception of the impure effluvia of the tobac-
co leaf instead of the  fresh breezes of heaven.

                   CHAPTER III.
      MASTICATION, INSALIVATION, AND DEGLUTITION.
Mastication—The teeth—Teeth, being adapted to the kind of food,
  vary at different ages and in different animals—Teeth classed
  and  described—Vitality of teeth, and its advantages—Causes of
  disease in teeth—Means of protection—Insalivation, and its uses
  —Gratification of taste in mastication—Deglutition.
  Having seen that a regular supply of nourishment is
carefully ensured by  the  constantly returning  impulses of
Appetite, we come  next  to examine the  mode  in which
the food  is prepared  for becoming a constituent part of the
animal machine, and endowed with  the properties of life.
  The first important step in the complicated process  of
digestion, is  that by which the food, after being received
into the mouth, is mixed with  the saliva and  broken down
till it  becomes of a uniform pulpy consistence, fit for being
easily  swallowed and acted upon  by the gastric juice on
it sarrival in the stomach.   The term mastication, or chew-
ing, is used to denote this operation ; and the chief instru-
ments by which it is performed are  the  teeth, the jaws,
the muscles  which move the jaws, the tongue, and  the
Balivary glands.  On each of  these we shal offer a  few
observations.
   The teeth vary a good deal according  to  the kind of
food on which the animal is destined to  live ; but  in man 
62
DIFFERENT KINDS OF TEETH.
 and the higher orders of animals they may be divided into
 three distinct groups :  1st,  The incisor  or cutting teeth,
 being the eight broad and flat teeth with a sharp cutting
 edge seen in front of the upper and lower jaws, and marked
 I in the'subjoined wood-cut, which represents one-half of
 the lower jaw, and consequently only one-fourth of the whole
 number of teeth.   Thus we find only two incisors marked
.in the wood-cut, although there are eight of them in all,
 viz., two more are on the other side of the lower jaw,  and
 four corresponding ones in the upper.  2rf, The cuspidati,
 canine,  or dog teeth, being the  sharp-pointed, roundish-
 bodied teeth, four in number, one, C, in  contact with each
 of the outer incisor teeth, and called canine from being large
in the dog and  carnivorous animals, and used by them for
the purpose of seizing and tearing their food;  and, 3d, The
molares or grinders, B G, twenty in number, situated at the
back part of the jaw,  and so called from their office being
to grind or bruise the food subjected to their action.*   The
term grinders, however, is sometimes restricted to the three
back teeth on each side, marked G, and seen to have  double
roots and a broad grinding surface ; and the two, B, inter-
vening between them  and the cuspidati are  styled bicus-
pidati or double-speared, from bearing a greater resemblance
to a  double-headed canine tooth than to the other grinders.
  * In Latin cuspis signifies the point of a spear; canis, a dog • mola,
a mill; incisor, anything which cuts. 
          RELATION BETWEEN TEETH AND FOOD.       53

   The teeth are modified in different animals to suit their
 habits of life.   In herbivorous  animals  the canine  teeth,
 for which they have no use, are comparatively undeveloped ;
 whereas in  carnivorous  animals, which  tear their prey in
 pieces, the canine teeth  are large, powerful, and pointed,
 and  the incisors comparatively  small.   In  these  animals
 they constitute what are properly called the  tusks, and in
 some species they are of a truly formidable character.  The
 molar or grinding teeth  differ in like manner, according to
 the nature of the food.  In herbivorous and  granivorous
 animals they are large and powerful, and to increase their
 efficiency the lower jaw admits of considerable lateral mo-
 tion  in a horizontal direction ;  whereas, in carnivorous ani-
 mals, it admits of motion only upward and  downward, as
 in opening and shutting the mouth.  The lateral grinding
 motion is very  evident in ruminating animals, such as  the
 cow,  which, after having filled its stomach with provender,
 is generally seen to lie down and ruminate, or chew the cud
 as it  is catted—the rumination  consisting  in  bringing up
 small masses of herbage from the stomach, and submitting
 them to a thorough mastication or grinding  between its
 molar teeth before being again swallowed and digested.
   From this relation between the food and the organs of
 mastication, naturalists  can tell with certainty, by simply
 inspecting the teeth, on what kind of food the animal to
 which they belong is intended to live ;  and  as  the teeth of
 man partake of the characters of those of both herbivorous
 and carnivorous animals, there cannot be a doubt that  his
 diet was intended to be of a mixed kind, not confined ex-
 clusively to either the vegetable  or thfi animal  kingdom.
  Hard and resisting as the teeth appear, they must still be
 regarded as living structures. Anatomically speaking, each
 tooth is divided into three parts : the fang or root, implant-
 ed in  the socket of the jaw-bone ;  the neck, or portion en-
circled by the gum ; and the white crown, appearing above
the gum, and covered with enamel.
  The root of each tooth is perforated longitudinally by a
small canal,  through which the bloodvessels and nerve are
admitted to its central parts.  From these bloodvessels the
tooth derives its nourishment when growing; but they  after-
ward almost entirely disappear.   From the nerve it derives
that sensibility which makes us instantly aware of the con-
tact of bodies either too  hot or too cold with the teeth;
                            5* 
54
VITALITY OF THE TEETH.
and which, when  the  nerve  is diseased, gives rise to the
racking pain of toothache.
   So effectually is life maintained in the teeth by this pro-
vision of vessels and nerves, that a tooth newly extracted
from the socket of a young animal, and  implanted in  the
fleshy comb of a cock, has been found to adhere and retain
its vitality; and, in like manner, if, in  early life, a tooth
extracted by accident be immediately replaced in its socket,
it  will generally adhere and live.
   The visible part or crown of the teeth is covered with a
very  hard  white  ivory-looking  substance called enamel,
which serves to prevent it from being worn down by friction,
and into which neither bloodvessels nor nerves have been
observed to penetrate.   Owing to this structure,  the tooth
can be safely exposed without sustaining damage—a privi-
lege on which most persons will be disposed to place a
higher value after having experienced the pains consequent
upon injury of the  nerve from a portion of the enamel being
broken off.
   An obvious advantage attending the vitality of the teeth
is, that it enables them to accommodate  themselves to the
growth of  the jaw and the rest of the system at  the diffe-
rent periods of life.  In early infancy, when the human being
is designed to live exclusively on his mother's milk, which of
course requires no mastication, and, consequently, no teeth,
the latter are still imperfectly formed and entirely  hidden in
the jaw : it is only at the end  of some months that the front
or cutting teeth begin to appear ;  and the whole set of milk,
deciduous,  or falling-out teeth, twenty in number,' is  not
completed till about or after the third year.   In the course
of three or  four years more, however, growth has advanced
so far that  the first set of teeth no longer fill the jaw ;  and
they soo'n begin to be  displaced by the second or perma-
nent  set, the gradual  developement of which commences
at  that period of life, and is not finished till the appearance
of the last  four grinders or wisdom-teeth, about the age of
maturity.
   It is a curious fact, that the infant is born with  the rudi-
ments of both sets of teeth in the jaw at  the same time
although neither makes its appearance  till long after birth.
The permanent teeth lie in a  line under the milk-teeth, and
it is from their growth causing the gradual absorption of
the roots of the first teeth that the latter no  longer retain 
               PRESERVATION OF THE TEETH.           55

 their hold of the jaw, but drop out as soon as the others are
 ready to protrude.   In the preceding wood-cut the situation
 of the permanent teeth before they emerge  from the jaw is
 rudely represented at A, where the outer surface of the jaw-
 bone has been removed on purpose to show the appearance
 of the roots.   But nothing of this kind is to be found in the
 adult jaw, the  parts marked A being inserted in the plate
 merely to illustrate what was once the position which the
 permanent teeth occupied.
   The changes  in  the condition of the teeth, it may be
 remarked in passing, indicate clearly what species of food
 Nature has intended for us at different ages.  In early in-
 fancy, when no teeth exist, the mother's milk is the only
 nutriment required ; and in proportion7as the teeth  begin
 to appear, a small addition of soft farinaceous food prepared
 with milk may be made  with  propriety, and gradually in-
 creased.   But it is impossible to look  at the  small jaw,
 moderate muscle, and imperfect teeth of early life, without
 perceiving that only the mildest kinds and forms of animal
 food are yet admissible, and that the diet ought to consist
 essentially of soft and unirritating materials.   It is not till
 the permanent teeth have appeared, that a full  proportion
 of the ordinary kinds of butcher-meat becomes either bene-
 ficial or safe.
   The teeth, being living parts, and at the same time en-
 dowed with a mechanical function,  are liable  to injury in
 both capacities.  Being composed chiefly of earthy matter,
 such as phosphate  and carbonate of lime, the contact of
 strong acids decomposes their substance, and leads to their
 rapid decay.  Hence the whiteness produced by acid tooth-
 powders and washes is not less deceitful  than ruinous in its
 consequences ;  and hence also great caution is  necessary
 in swallowing the acid drops frequently prescribed by the
 physician, which  ought  never to be allowed to come into
contact with the  teeth.
   The teeth being constantly moistened  with  saliva, have
a tendency to become incrusted with the tartar or earthy
matter which it contains in solution, and which is separated
 from it partly by the evaporation of  the more fluid consti-
tuents in breathing, and partly by chemical decomposition.
As this incrustation not only destroys the  beauty of the
ieeth, but also promotes their decay,  it becomes an object
of care to remove it as soon as it is formed ; and the most 
56
PRESERVATION OF THE TEETH.
effectual mode of doing so is to brush the teeth regularly
twice a day—especially in the  morning, when the quantity
is greatest—with a brush  dipped in'soft  water, till eve^Y
particle is removed.  - The addition of any soft  impalpable
powder will assist in the effect; but nothing capable of
acting chemically on the teeth, or of injuring them by fric-
tion, ought ever to be resorted to.   Washing  the  mouth
after every meal is also a good preservative.*
  When the  teeth  are  not used for a time, and when di-
gestion is impaired, the quantity of tartar which  accumu-
lates on them  is very great.  Hence  they are always most
incrusted in the  morning, and in fevers and other affections
where no food is taken, and the stomach is  at the same
time disordered.   I  have seen one instance in which a thick
crust of tartar was removed by  a  dentist in the belief-of its
being a diseased tooth—the 'tooth itself on which it was
formed being left in the jaw perfectly sound.
  When the tartar is not duly removed, its presence injures
the teeth, irritates the gums, and generally leads, sooner or
later, to considerable suffering.   The regular washing and
brushing abovementioned ought, therefore, to be sedulously
practised at every period of  life, and taught  as a duty to
the- young.   When digestion  is very vigorous, the health
good, and the diet plain and containing a full proportion of
vegetable matter, the deposition of tartar seems to be di-
minished, and the teeth to be  naturally of a purer white.
Many rustics and savages thus possess teeth which would
be envied in a town.
   When  digestion  is impaired, and acidity prevails in the
stomach, the mucous secretions in the mouth also become
altered in character, and by their incessant contact injure
and even destroy the teeth.  From this cause we often see
the  teeth of young people  in a state of complete decay.
They are, in reality, the subjects of chemical decomposition,
  * M. Cadet de Qassicourt recommends thefollowing compound as
a safe and excellent dentrifice, viz., of white sugar and powdered
charcoal each one ounce, of Peruvian bark half an ounce, of cream
of tartar one drachm and a half, and of canella twenty-four grams,
well rubbed together into an impalpable powder.  He describes it
as strengthening to the gums and cleansing to the teeth, and as de-
stroying the disagreeable odour in the breath which so often arises
from decaying teeth ;  and, as ^.preventive of toothache, I have heard
washing the mouth and  teeth twice'a day with salt and water
strongly recommended by a gentleman who had both experienced
and observed much benefit from it. 
SALIVA AND ITS USES.
57
 smd eaten away by the  morbid secretions of the mouth ■
 and hence, in such cases, we generally find the individual
 complaining  of heat and soreness of the tongue, gums, and
 mouth, and occasionally of the teeth being "set on edge.1'
   Considered as living parts, the teeth require some addi-
 tional care.  In  that capacity they are exceedingly apt to
 suffer from sudden  changes of temperature.  Being from
 their solidity rapid conductors of heat, their internaf nerv«
 speedily becomes affected by the alternations of tempera-
 ture to which they  are  daily exposed, both in taking food
 and in the change from  a warm to  a cold atmosphere.  It
 is a not  uncommon practice, for example, to take a glass
 of cold wine or water immediately after finishing a plateful
 of very hot  soup ;  and  it is quite  usual to take  tea  and
 coffee and every  kind of meat as hot as they can possibly
 be swallowed—than which  practices it would  be difficult
 to imagine anything more hurtful to the teeth.
   For the same reason,  in going out at night from a warm
 room  to the cold air, it is desirable to  protect the teeth
 from the influence  of  the  sudden  change,  bv breathing
 through two  or three folds of a silk handkerchief or through
 a woollen comforter.  When the teeth and lower part of
 the face  are  left  exposed in such circumstances, rheuma-
 tism and toothache not unfrequently ensue from  the direct
 impression of the cold air upon parts rendered more sus-
 ceptible by the preceding heat.
   The great source of  injury to the teeth, however, both
 in childhood  and in mature  age, is disordered  digestion.
 If the health be good, and the stomach perform its functions
 with vigour,  the  teeth will resist much  exposure without
 sustaining  injury.  But  if these  conditions fail, they will
rarely continue long unscathed.
   It is almost always from the latter cause that, in infancy,
 teething  so oftea gives rise  to serious constitutional dis-
order.
   Something more,  however, than the mere action of  the
 teeth and jaws is required to prepare the morsel for being
swallowed.   If  we  take a   bit  of dry biscuit  or  mealy
potato  into the mouth, and attempt  td masticate it, we  en-
counter at first no  small difficulty from  the  stiffness and
 resistance of the dry mass,   and  feel instinctively that it
 would be in vain  to attempt  to swallow it, until moistened
either by continued mastication or by the admixture of fluid 
58             mast'ication--RUMINATION.

from without.   In ordinary states of the system, accord-
ingly, a fluid called saliva or spittle is  copiously secreted
and poured into the mouth for this very purpose ; and the
process by which its  due admixture with the contents of
the mouth is accomplished is called the  insalivation of the
food.
  To provide  this necessary fluid, and to connect its sup-
ply directly with the process of mastication to which it is
subservient, several glands for  its secretion  have been
placed in  the immediate  neighbourhood of the mouth and
jaws, in such  a way that  the latter cannot be opened and
shut without  affording them a stimulus, and still  farther
increasing the secretion which  the presence of the morsel
is  itself sufficient to begin.  From  this  arrangement it
follows, that the more perfectly mastication  is performed,
the more thoroughly does the morsel  become impregnated
with the salivary fluid, and the better fitted is it  rendered
for subsequent deglutition and digestion.
  The  apparatus of  mastication  varies according to the
kind of food on which the animal is destined to live ;  but
in the higher orders of animals it consists essentially of the
parts already mentioned.   In some animals, however, which
live on soft gelatinous food—as  the  whale—no  teeth are
to be found, because their peculiar power is not  required.
In others—as  the  granivorous  or grain-eating birds—the
grinding or triturating process is effected, not in the mouth,
but  in  the gizzard,  where the food (mixed  with gravel,
which  the animal is instinctively impelled to swallow for
the purpose) is effectually bruised and  softened  down  by
the strong muscles which constitute the greater part of  its
substance.   In these  instances  the gravel is the grinding
instrument, and without its presence  digestion cannot  be
carried on any  more than it could in man without the agency
of teeth.                                         6   J
  The degree  of mastication required  varies also according
to the mode  of life of the animal, and the digestibility of its
food.   Animal food, for example, being easy of digestion,
requires less  mastication  than vegetable  food,  which is
more  difficult.  This is so much  the  case, that most ani-
mals which live on fresh  vegetable matter spend half their
waking hours in  ruminating or  remasticating  the food,
which  they  have  already cropped  and  stored up for  the
purpose in one of their four stomachs.   To this necessary 
MASTICATION OF THE FOOD.
59
 act in them, Providence seems to have attached a high de-
 gree  of gratification, for the very purpose of ensuring its
 regular performance.
   Man, being  naturally omnivorous, or adapted  for the
 digestion of both animal and vegetable substances, holds,
 as it  were, an intermediate place in regard to the rapidity
 of mastication.   He is neither obliged to ruminate like the
 cow,  nor can he beneficially bolt his food with the rapidity
 displayed by birds of prey.  His object is merely to reduce
 the alimentary  mass to a soft  and  pulpy consistence, and
 digestion is promoted or retarded in exact proportion as he
 approaches or falls short of this point.  Hasty mastication
 is consequently  injurious, because it prevents the food from
 being sufficiently broken down and impregnated with saliva;
 and  the more uncommon error of protracted mastication is
 also injurious, owing to the undue dilution which the mass
 sustains from the overflow of the salivary secretion.
   Due mastication  being  thus essential to healthy diges-
 tion,  the Creator, as if to ensure its being adequately per-
 formed, has kindly so arranged, that the very act of mas-
 tication should lead  to the gratification of taste—the mouth
 being the seat of that sensation.  That this gratification of
 taste  was intended, becomes obvious when, we reflect that,
 even  in eating, Nature makes it our interest to give atten-
 tion to the process in which we are for the time engaged.
 It is well known, for example, that, when food is presented
 to a hungry man, whose mind  is concentrated  on the in-
dulgence of his appetite, the saliva begins to flow unbidden,
 and what he eats is  consumed with a peculiar relish and is
 easily  digested.    Whereas, if  food  be  presented  to an
individual who  has  fasted  equally long, but whose  soul is
 absorbed in some great undertaking or deep emotion, and
who is consequently  insensible to the gratification of taste,
it will be swallowed  almost without mastication,  and with-
out sufficient admixture with the saliva—now deficient in
quantity—and, therefore, lie on the  stomach for  hours un-
changed.  In this point of  view the peculiarly English
custom  of reading the  newspapers or magazines during
breakfast is more hurtful than one  would suppose ;  and
many  dyspeptics have been surprised at the benefit result-
ing from its discontinuance.   However, therefore, philoso-
phy and morality  condemn the undue cultivation of our
bodily appetites, it cannot be denied  that a certain degree 
 60              USES OF MASTICATION.

 of attention  to taste, and to the pleasures of appetite, r*
 both reasonable and beneficial ;  and it is only when these
 are abused that we oppose the intentions of Nature.
   From the existence of this intentional relation between
 mastication and the  salivary secretion, the  latter is always
 most  copious in those creatures whose food requires con-
 tinued mastication.   In ruminating animals,  accordingly,
 the salivary glands are numerous and of great size, while
 they are at the same time so situated that  the play of the
 muscles in the act  of rumination  communicates  to them
 a  proportionate stimulus.   In those, again, which do not
 masticate at  all, but swallow their  food  entire,  there is
 scarcely any salivary secretion, and  the glands appropriated
 to it are very small.  Birds, and many fishes  and  reptiles,
 belong to the latter class.
   From the foregoing explanation  of the object and con
 ditions  of mastication, the  reason will be apparent why
 fluids do not require to undergo that process, and also why
 dry, mealy substances stand in need of protracted chewing
 before they can be easily swallowed. When hot, spicy food
 is  taken into the mouth the secretion of saliva is immensely
 increased, obviously for the purpose of diluting the excess
 of stimulant before it shall be allowed to reach the stomach.
 But  when the food is of a  mild and  unirritating quality,
 much dilution is unnecessary, and-the secretion is accord-
 ingly moderate.
   The chief purpose of mastication, then, is evidently the
minute division of the aliment, so as to admit of its being
 easily acted upon by the gastric juice when received into
the stomach.   Dr. Beaumont, however, seems to me to go
too far in inferring,  that " if the materia alimentaria could
be introduced into  the stomach in a finely divided  state,
the operations of  mastication, insalivation, and deglutition
would not be  necessary."   It would require a more exten-
sive  range of experiments  than that which he has made,
to  prove  that  " aliment is as well digested and assimilated,
and allays the sensation of hunger as perfectly, when  in-
troduced directly into the stomach  (through an opening in'
the side) in a proper state of division, as when  the usual
previous steps have been taken."*  It is quite true that
 ♦ Experiments and Observations on the Gastric Juice and the
 Physiology of Digestion, by William Beaumont, M.D., of the United
 States Army, reprinted with Notes by Andrew Combe, M.D., Edin
 burgh, 1838. 
DEGLUTITION—THE GULLET.
61
 mastication and deglutition are chiefly mechanical process-
 es ;  but it is difficult to believe that so much care would
 have been taken to provide a proper supply of fluid of a
 constant and peculiar character like saliva, if water were
 capable  of answering the purpose as  well, and if saliva
 were useful only in lubricating the food.  There subsists,
 moreover, between the sense of taste  and the  power of
 digestion a certain  relation, which renders it more  than
 probable that the active gratification of the former durino-
 mastication is  favourable  to  the  production and  flow of
 nervous energy toward the stomach, and, consequently, in
 so far conducive to  the healthy performance of digestion
 that even in that point of view insalivation could  not easily
 be dispensed with.  Dr.  Beaumont's experiments, however,
 abundantly demonstrate that  Monte"gre, and  those  who,
 along with him, consider the saliva as the principal agent in
 digestion, have not a shadow of foundation for their opinion.
   When unmasticated food is introduced into the stomach,
 the gastric juice acts only upon its surface, and changes of
 a purely chemical nature sometimes commence in  its sub-
 stance  before its digestion can be effected.  Hence  often
 arise, especially in children, those pains and troubles, that
 nausea  and acidity, consequent on the continued presence
 of undigested aliment in the stomach.  By a peculiarity
 of constitution, however, the stomach will not long retain
 food which it  cannot dissolve.  After a number ol hours
 —varying, according to the  state of  health, from  one or
 two to ten, or even twenty—it is either  rejected  by vomit-
 ing, or transmitted unchanged to the intestine,  where its
presence irritates and gives rise to colic, flatulence, bowel-
complaints, and, in  delicate children, not unfrequently to
convulsions.   Hence another proof of  the importance of
slow and deliberate mastication.
  As soon as the morsel has been thoroughly masticated
and impregnated with saliva, it is ready for transmission to
the stomach.   To this part of the process the term deglu-
tition or swallowing  is applied.
  Immediately  at the back part of the mouth several pas-
 sages present themselves, leading in different directions—■
 one upward and forward into the nose, another downward
 and in front into the-windpipe, and a third  downward and
 behind into the oesophagus, gullet or meatpipe, and stomach,
 The last is the passage taken by the food ; and the violent 
63
DEGLUTITION.
 coughing and occasional suffocation induced when it acci-
 dentally passes  into the windpipe, are but a specimen of
 the serious evils which would be continually  occurring if
 some provision were not made to obviate the danger, while
 the rarity with which such accidents actually happen, proves
 the almost unfailing efficacy of that which has been devised.
   The passage of the food into the nostrils is prevented by
 the interposition of a moveable fleshy curtain or valve hang-
 ing down from the palate, and visible at the back part of the
 mouth;  this, in the act of  swallowing, is stretched back-
 ward, so as to extend to the back part of the throat,  and
 thus entirely shut up the opening into the nostrils.   The
 passage into the windpipe, again, is protected  by a cartila-
 ginous lid or covering called epiglottis, (from em, epi, upon,
 and y^urrtr, glottis, the tongue,) which projects backward
 from the. root of the tongue, and conducts the morsel over
 the glottis or opening  of the windpipe.  The epiglottis,.
 however, is greatly assisted in this operation by that rising
 upward arid forward of the gullet and windpipe to meet the
 morsel, of which we are conscious, and  which can be felt
 by  the hand  in  the  act of swallowing, and the effect of
 which is in some degree to hide the glottis under the back-
 ward  projection of  the  root of the  tongue,  and  allow the
 morsel to drop past it into the gullet.
   Once fairly  in the gullet, the course of the food into the
 stomach is easy enough.  The gullet is simply a round
 tube, made up of two rows of muscular or fleshy fibres,
 the one longitudinal and the other transverse and circular,
 with a soft moist lining membrane to facilitate the trans-
 mission of its  contents.   When  the morsel is introduced,
 its  upper part contracts involuntarily, and  pushes the mass
 downward ; the  portion now reached contracts in its turn,
and propels it farther; and so on in succession till it arrives
 at the stomach.
  Deglutition  or swallowing is thus a more complicated
 operation  than at first sight  it appears to  be.   On looking
at any person  eating, one is apt to think   that  the  morsel
passes along the gullet into the stomach by its own weight;
but we speedily perceive the error, when  we recollect that,
 in the horse and the cow, for example, the mouth is on a
 level with  the ground when feeding  or drinking, and that
 the morsel or water is consequently  propelled upward into
 the stomach against its own gravity.   It is well known also, 
TARIETY OF SOURCES OF FOOD.
63
and often made a matter of public  exhibition, that a man
can swallow even liquids when  standing on the crown of
his head, with! the natural position of the stomach reversed.
   Deglutition is easier and  quicker when  the  appetite is
keen, and the alimentary bolus or morsel is moist and pro-
perly softened.  It is slow and difficult when the morsel- is
dry and  mealy, and  the appetite nauseated.   In vomiting,
the action of the  muscular  fibres is inverted, or proceeds
from, the lower end  of the gullet toward the mouth ;  and
hence the object is  carried  upward instead of downward,
 as in the natural order.

                    CHAPTER IV.
ORGANS OF DIGESTION--THE STOMACH—THE GASTRIC JUICE.
Surprising power of digestion—Variety of sources of food—All
  structures, however  different, formed from the same blood—Ge-
  neral view of digestion, chymification, chyliflcation, sanguifica-
  tion, nutrition—The stomach in polypes, in quadrupeds, and in
  man—Its position, size, and complexity in different animals—Its
,  structure ; its peritoneal, muscular, and villous coats ; and uses
  of each—Its nerves and bloodvessels ; their nature, origins, and
  uses—The former the medium of communication between the
  brain and stomach—Their relation to undigested food—Animals
  not conscious of what goes on in the stomach—Advantages of this
  arrangement—The gastric juice the grand agent in  digestion—
  Its origin and nature—Singular case of gunshot wound making a
  permanent opening  into the stomach—Instructive experiment
  made by Dr. Beaumont—Important results.
   If, in the whole animal economy, where all is admirable,
 there be one operation which, on reflection, appears more
 wonderful than another, and  which evinces in a higher de-
gree the prodigious resources and power of the  Creator in
 fashioning everything to His own will, it is perhaps that by
 which the  same kind of nutriment is extracted from the
 most opposite varieties of food consumed by living beings.
 For, singular as it may appear,  recent researches  tend to
 establish the fact, that, eve(n in animals differing so widely
 in their  aliment as the herbivorous and carnivorous quadru-
 peds, the ultimate products  of digestion in both—the chyle
 and  the blood—are identical in composition, in so far at
 least as can be determined  by their chemical analysis.*
    Remarkable, .however, as  this uniformity of  result un-
 doubtedly is, it becomes still more striking when we con-
 template the variety of sources from which food is  derived
 for the  support of animal life.  To use the words of an able
     » See Koget's Bridgewater Treatise, note at p. 58, vol. ii. 
64     ALL STRUCTURES FORMED FROM THE BLOOD.

writer already quoted, " There is no part of the organized
structure of an animul or vegetable, however dense its tex-
ture or acrid  its qualities, that may not, under certain  cir-
cumstances, become the food of some species of insect, or
contribute in some mode to the support of animal life.
The more succulent parts of plants, such as the leaves or
softer stems, are the  principal sources  of nourishment to
the greater number of largeT quadrupeds, to multitudes of
insects, as well as to numerous tribes  of other  animals.
Some plants  are more particularly assigned as the appro-
priate nutriment of particular species, which would perish
if these ceased to grow :  thus, the silk-worm subsists almost
exclusively upon  the leaves of the mulberry tree ;  and
many species of caterpillars are attached each to a particu-
lar  plant, which they prefer to all others.  There are at
least fifty different species of insects that feed upon  the
common nettle ; and  plants of which the juices are most
acrid  and poisonous to the generality of animals, such as
euphorbium, henbane, and nightshade, afford a wholesome
and delicious food  to others."*   Nor are the precision  and
accuracy with which the same fluid—the blood—affords to
every structure of  the body the precise  species of  nourish-
ment  or secretion  which  its elementary  composition re-
quires, however  different  each may be from the  rest in
chemical  qualities, less  admirable and  extraordinary than
its own original formation from such a variety  of materials.
To bone  the  blood furnishes the elements of bone with
unerring accuracy  ; to  muscle the same blood furnishes
the elements  of muscle—to nerves the elements of nerve—
to skin the elements of skin—and to vessels the elements
of vessels ;—and yet,  while each of these differs somewhat
in composition from the others, the constituent elements of
the blood by  which they are furnished are everywhere the
same.
  Similar phenomena, indeed, occur in the vegetable world;
but this, instead of  diminishing our wonder, tends rather to
augment it.   The same elements, extracted from the same
soil, are converted into every variety of vegetable product__
into leaves of every shade of green, flowers of every form
and tint, and juices of. every quality, from the deadly poison
up  to bland  and life-supporting  milk.   Nay, even in  the
same plant—as in the poppy—we sometimes find the seeds
        * See Roget's Bridgewater Treatise, vol. ii., p. 59, 
               GENERAL VIEW OF DIGESTION.          65

and the capsule which covers them endowed with the mest
opposite properties.
  It would be very interesting to discover by what resources
Nature thus effects  the  production of  the same kind of
nutritive fluid or chyle from so great a variety of substances,
and apportions to every part the precise elements of which
it stands in need ; but it is doubtful whether  the human
faculties were  ever designed to penetrate  so far into the
modes of vital action, and, in the meantime, it will be better
for us  to confine our  attention to that branch of the inquiry
which  we  can  easily  comprehend, and  which bears a direct
reference  to our  own welfare.   We know already  that
certain organs  are concerned in the processes  abovemen-
tioned, and that  these organs act  under the regulation of
certain general  laws.  If we make ourselves  acquainted
with, and  carefully fulfil, these laws, we reap a rich reward
in the enjoyment of sound and vigorous digestion.  Where-
as, if, either from ignorance or from carelessness, we neglect
their fulfilment, we bring upon ourselves a severe  punish-
ment  in the form of dyspeptic or nervous disease.   As-
suredly, then,  alternatives like these ought to  excite some
desire for information in the minds even of the most indif-
ferent.
  Before, however, commencing a description of the organs
concerned in digestion, it will be  useful to take a  general
view of the different stages of preparation through which
the food passes, between its  reception into  the stomach and
its  assimilation, or ultimate conversion into a constituent
part of the animal body, and becoming endowed with the
properties of life.  The reader will thus be better  enabled
to understand  the meaning of various terms and  expres-
sions,  the  frequent use  which  it is  almost impossible to
avoid,  even in the beginning of our exposition.
  When the food is  received into the stomach, it  is there
subjected to the action of a  solvent fluid, called  the gastric
or stomach juice, (from yaarrjp, gaster, stomach,) by which
it is gradually converted into a soft grayish and pultaceous
mass, called chyme, {from xvp°Ci chymos, humour or juice ;)
whence the process is called chymification, or chyme-making.
The chyme, as fast as it is formed, is  expelled by the  con-
tractile power of  the  stomach into the duodenum, (from
duodenus, consisting of twelve, because it is supposed to ba
about  twelve inches  long,) or first portion of the intestines, 
66
GENERAL VIEW OF DIGESTION.
It there meets with the bile from the liver, and with the
pancreatic juice, which very  much resembles  the  saliva,
from the. pancreas or sweet bread, {nag, pas, all, and icptag,
kreas, flesh, it being of a fleshy consistence,) a large gland
which lies across the spine a  little below the stomach, and
is marked  P in the wood-cut  given in the chapter on Chy-
lification.  By t?he action of these two fluids the chyme is
converted  into two distinct portions—a milky white fluid
named chyle, {from x^og chylos, chyle,)  and a thick yellow
residue.   This process is  called  chylification, or chyle-ma-
king.   The  chyle is then  sucked in by absorbent vessels,
extensively ramified on  the inner membrane or lining of
the bowels,  and  sometimes named, from the white colour
of their contents, lacleals or milk-bearers, (from lac, milk.)
These lacteals ultimately  converge into one trunk, named
the thoracic duct or chestpipe,  (from its course lying through
the thorax or chest,) and which terminates, as  will be seen
in a cut in Chapter VI., in the great vein under the clavi-
cle or collar-bone, hence called subclavian vein, just before
the latter reaches the right  side of  the heart; and there
the chyle is poured  into the general  current of  venous
blood.
   But although thus  mingled with the blood, the chyle is
not yet sufficiently capacitated for its duties in the system.
To complete its preparation, it still requires to  be exposed
to the action of the air during respiration.  This is accord-
ingly  done  by its passing through the lungs  along with
the dark  and venous  blood,  which stands in  need of the
same change.  In the course  of this process both the chyle
and the venous  blood are converted into  red, arterial, or
nutritive blood, which is afterward distributed by the heart
through the  arteries, to supply nourishment and support to
every part of the body.   Hence the change which t3kes
place  in the  lungs is properly  enough named sanguification,
or blood-making. *
   The thickish  yellow residue left in the duodenum after
the separation of the chyle from  the chyme, is that  portion
of the food which affords no nourishment, and  which, after
traversing the whole length of the  intestinal canal, and
undergoing still farther change, is thrown out of the body in
the shape of faces  or excrement.  But in  this course  its
  * For a full explanation of the nature, importance, and  laws of
respiration, see the author's Principles of Physiology, &c., 10th edi.
tion, chap. iz. 
STOMACH IN THE LOWER ANttfALS.         6?
bulk is increased and its appearance changed, by the addi-
tion  of much waste  matter, which, having already served
its purposes in  the  system, is at last, as will be afterward
shown, thrown  out by the same channel.
  With this general  view of the nature of Digestion before
us, we can now examine more satisfactorily the structure
and  mode  of action of each of the organs concerned  in
effecting it.  Chymification being the first step in the com-
plicated process, we shall begin with the organ by which
it is  performed, namely, the Stomach.
  In the lowest'class of animals—the  hydra, for example,
which belongs to the order of gelatinous polypi, and abounds
in stagnant pools—the stomach is like a simple bag, devoid
of any peculiar organization ; or,  more properly speaking,
the  animal itself is  nothing more  than a living stomach ;
for the  minutest inspection can discover in it no trace  of
anything like vessels, nerves,  brain, lungs, heart, or other
known organ.   Even the experienced eye of Cuvier, aided
by a powerful microscope, could  detect in their structure
nothing more than a transparent parenchyma, full of darkish
grains or points, and offering no trace of any distinguisha-
ble organs.*  In form the animal somewhat resembles the
finger of a glove, the hollow in the centre  being appropri-
ated  for the reception of its food  ; and yet, with  all this
simplicity of structure,  it not  only moves and  swims, but
seizes its prey by  means of its tentacula, thrusts it into
its cavity, and digests it  visibly—" d vue d'ceil."  And what
is still more strange, when it is turned inside out,  the
surface which was formerly the exterior of the body, now
digests as actively and efficiently as if it had never served
any other purpose.
  Bloodvessels being merely pipes serving for  the convey-
ance of nourishment from the place where it  is stored  up
and  prepared, to those  more distant parts which stand in
need of it,  it is obvious that in animals of this  very simple
description, where every part of the internal surface  of the
body is  already in immediate contact  with its food, and
itself imbibes or absorbs directly all the nourishment which
it requires, they would be entirely superfluous,  and  accord-
ingly none  are to be found.
  Owing to this extreme simplicity of organization, a hydra
may be  cut into pieces, each of which will become a per-
           » Cuvier's Regne Animal, vol. ii, p. 296. 
68          THE HUMAN STOMACH DESCRIBED.

feet animal.  But in proportion as we ascend in the scale of
creation, the organization becomes  more complicated, and
the functions more  numerous and also more dependent on
each other;  so that, when we arrive at man—the highest
of all—we find that the loss or injury of any vital organ
puts a stop to, or impairs, the action of all the rest.   It is
impossible, however, in an  elementary work like this, to
trace the gradation through  the different series of animals.
We must confine our examination to man, and only borrow
from other creatures such illustrations as may be necessaij"
for throwing light upon the human structure. 
THE STOMACH.                  69
  In man, then, the stonwch is a  large membranous and
jnuscular bag, lying under the convexity of the lower ribs
of the left side, and stretching toward the right a little be-
yond the hollow commonly called the pit of the  stomach.
In shape it somewhat resembles the bag of a bagpipe, as
will be  seen from the annexed figure ; its  left  or larger
extremity being in contact with  the ribs, and its right or
narrow extremity situated under the pit of the stomach.
  The position of the stomach (Stm.) relatively to the chest,
bowels,  and liver, will be understood  by  inspecting the
figure on the preceding page.  It is separated from the cavity
of the chest by the diaphragm or midriff DD, with which its
upper surface is in immediate contact, and through which
the gullet passes to enter its left extremity.   Its right or
pyloric  extremity, marked P in  the subjoined  cut, lies
close to the lower surface of the liver, (Livr.,) the latter
being a little  displaced to show  its situation.   On the
lower surface it has the appearance of resting on  the intes-
tines, as if imbedded among their folds.
  The  parts of the stomach which have received names
and require to be noticed, are—the cardiac orifice, (marked
C in the following figure, and so named from being near the
     Ktap, hear, or heart,) in which the gullet terminates, and
^   through which food and drink are introduced ; P, the pylo- 
70           THE STOMACH VARIES IN SIZE.
rus, or pyloric orifice, (from irvlopog, pyloros, a gatekeeper,
because it allows none but digested food to pass out.) where
the intestine called  the duodenum  begins,  and through
which the chyme passes after digestion is completed, and
which, when the stomach is full, is nearly on a level with
the cardia,  although  when  empty it is lower; SS,  the
smaller arch or curvature ; and GGG, the greater arch or
curvature.   The spleen is  attached to that part of  the
larger arch marked with dotted points.   From the situation
of the cardia 0, and its  connexion with the gullet, it will
be at once perceived that this forms one of the points of
attachment by which the stomach is  retained in its place.
  In size the stomach varies much in different individuals,
as well as in different animals, according to the bulk and
quality of their food.   As a general rule, it is larger among
the labouring poor than among the rich, as  the former re-
quire a larger quantity of their inferior food  to obtain from
it an equal amount of nourishment.  For the same reason,
animals which subsist on vegetable substances have a very
capacious stomach, while those subsisting  on animal  or
concentrated food have  it simple and small.  In man  its
capacity  may be diminished or augmented  within certain
limits,  by corresponding modifications of diet.   In some
gluttons,  and in  cases of diseased  appetite, it has been
found of enormous dimensions;  but this   rule does  not
always hold, for the stomach is sometimes  smaller  than
usual  in  immoderate eaters, and  then  its  contents  pass
through only partially digested.
  In accordance with this relation between the capacity
and structure of the organs of digestion and the quality  of
food, the stomach and intestines are found to be very small
and short  in carnivorous quadrupeds  and   birds of prey,
which are intended to live on concentrated aliment.   The
same is  the  case  with  the  granivorous or grain-eating
birds,  as  their food also is contained  in a small bulk.  But
in  herbivorous animals—in the food of which the nutritive
principle  forms  a very small proportion  of the whole,  per-
haps not  one-twentieth, and  which, consequently, require a
large bulk of it for their sustenance—the digestive appara-
tus  is on a large scale, as any one may  conceive in a mo-
ment, by comparing the  portly protuberance of the cow
with the lank paunch of the greyhound.  The cow, in fact
Is little else but a living laboratory for  the  conversion of 
            STOMACH IN ■CMINATING ANIMALS.         71

vegetable into animal matter; and accordingly, not only is
its stomach  large and complex, but its intestinal canal is
nearly twenty-four times the length of its body ;  whereas,
in some carnivorous animals the  whole intestine does  not
exceed once their own leno-th.
  In ruminating animals, such as  the  sheep  and ox,  the
stomach, as  will be  seen from the annexed figure, not only
is large, to adapt  it to the  bulky  nature of their food,  but
is complicated  in its structure, to fit  it for effecting  the
great changes which vegetable aliment requires to undergo
before it can be converted  into blood.  It may indeed be
said to consist of four distinct stomachs conjoined.  In the
first of these, AA, termed  the paunch, the herbage is de-
posited  when  first swallowed after hasty and  ineffectual
mastication.  It there undergoes a kind of maceration or
sleeping in a fluid provided for the purpose ; after which it
passes from the paunch into a smaller bag, called the  reti-
culum, or  bonnet, B, which, in some animals, such as the
camel and dromedary, is designed exclusively as a reservoir
for water,  which being there stored up in large  quantities,
ready for use when wanted, fits them in a wonderful man-
ner for travelling through the arid deserts  where no water
is to be obtained, and where, without some such provision,
they would of course soon perish.   So admirably is the re-
ticulum adapted for this special purpose,  that the water con-
tained in it undergoes little or no change  either in quality 
72          STOMACH IN GRAIN-EATING BIRDS.
 or quantity, although if it were  collected in the ordinary
 digesting stomach, it  would be entirely absorbed  in  the
 course of a few minutes.   It is not even  mixed with the
 food which  is swallowed  after it, as the  animal has  the
 power of directing  solids  at once into  the other cavities.
 From the reticulum the alimentary mass is again returned
 to the mouth, there to be thoroughly masticated and mixed
 with  the saliva; after which  it descends  a second  time
 through  the gullet: but, instead of passing, as before, into
 the paunch, it enters the third bag, omasum, or many-plies,
 C, where it undergoes farther changes, and is then trans-
 mitted to the fourth portion, D, adjoining the pylorus, and
 named ab-omasum, or red-bag.   The last portion is exactly
 similar in structure and in function to the  simple stomach
 of man  and the other mammalia, and  is, in fact, the true
 stomach, the other three being merely preparatory organs.
    The first part of the process, by which the food is taken
 hastily into the paunch  and  afterward  sent back to the
 mouth  in   detached  portions  for farther  mastication,  is
 called rumination  or chewing the cud, and those  species
 which perform  it  are thence  called ruminating animals.
 Sheep and cows may be seen  lying  ruminating in pasture-
 fields after having cropped as much herbage  as fills the
 paunch ; and feeding is thus rendered to them a source of
 prolonged  enjoyment.
    In those  birds, again, which live on hard grain  and seeds,
 and possess no organs of mastication wherewith to bruise
, or grind them down, another modification  of the digestive
 apparatus  is found. '  Nature  has furnished them  with  a
 membranous bag, called  a crop or craw, into  which trie
 food  is  received, and where  it is slightly softened  by  a
 mucous  fluid secreted  from the surface of  the bag.   Thus
 prepared, it is  transmitted into an organ analogous to the
 stomach of other animals,  and called the gizzard, which
 has a very singular structure.  Its walls are composed of
 four distinct portions of thick  tough muscular substance, a
 large one at each  side of the cavity and  a small  one  at
 each end.   The inner surface of  the muscle is lined with
 an extremely callous  cuticle, approaching in hardness  to
  cartilage or horn.   When  the moistened grain is  introduced
  into  the gizzard from the  crop, the muscular walls of the
  gizzard  enter into  powerful action, and, by their alternate
  contraction and relaxation, bruise the  grains as between 
 STRUCTURE OF THE STOMACH—COATS OF THE STOMACH. 73

two grindstones.   In some birds their action is assisted by
a quantity of small gravel, purposely swallowed along with
the food ; and  it  is well  known  to  seamen that poultry
never thrive on a voyage, however well they may be fed,
if gravel or coarse sand, as well as food, be  not  placed
within  their  reach.   Mr. Hunter  has  counted  as  many
as a thousand  small  stones in the gizzard of a common
goose.*
   The  astonishing force with  which the  muscles  of the
gizzard act, and the resistance of its lining membrane, may
be  conceived from the experiments of Spallanzani and
Reaumur, who compelled geese and other birds to swallow
needles, lancets, and  other  sharp  metallic  bodies, and, on
afterward killing  them, regularly found  the points broken
off and the edges  blunted, without any  injury having been
sustained by the gizzard itself.
   In  structure, the stomach of both  man and animals
consists of three membranous layers or coats, of follicles or
glands, and of numerous bloodvessels and  nerves.
   The first or external  layer  is the  smooth, glistening,
whitish membrane, which is familiar  to all who have ever
seen  an animal opened, or a fowl drawn for cooking.  It is
a fold of the  tough shining membrane called peritoneum,
(frorn nepireivu, periteino, I extend round,) which lines the
abdomen, and constitutes the outer covering of all the ab-
dominal organs.   Its use is obviously  to  strengthen the
substance of the  stomach, to assist in  binding down this
and the other organs  in their respective situations, and, by
the smoothness and constant moisture of their surfaces, to
enable  them  to move upon each other, and adapt  them-
selves freely to their  different states of  emptiness and dis-
tention.
   The second, middle, or muscular coat consists of  fleshy
fibres, one layer of which, running longitudinally from the
cardia  to the pylorus, seems to be a continuation of the
longitudinal muscular fibres of the gullet:  another runs in
a circular direction,  embracing, as it were, the stomach
 from  one curvature to the other, and constituting what are
 called the transverse fibres.  A third  and more internal
 layer of this  coat, is spoken of by Sir  Charles Bell as  a
   * The above descriptions and figure are taken, with slight alt i ra-
 tions, from the Treatise on Animal Physiology in the Librar/ of
 Useful Knowledge.
                            7 
74
COATS OF THE STOMACH.
continuation of  the  circular  fibres of the gullet,  whici
divide  into two  parcels, the one  distributed over the  left
or larger end,  and the other over the pyloric or narrower
end.
  *The uses of the muscular coat have, as we  shall after-
ward see, a direct reference to the special function of diges-
tion.   By the  joint action of its  longitudinal and circular
fibres,  the stomach is enabled to  contract, and  shorten its
diameter in every direction, so as to adapt its  capacity to
the volume of its contents ; while, by their successive ac-
tion, or  alternate contraction and relaxation,  a kind of
churning motion is produced,  which contributes greatly ta
digestion by the motion which it imparts  to the food, and
the consequent  exposure which it effects  of every  portion
of it in its turn  to the contact of the gastric juice.
   The force and  rapidity of these muscular contractions
are modified by  the  more  or  less stimulant nature of the
food', the state of health,exercise, and other circumstances -T
but, according to Dr. Beaumont,  the ordinary  direction
in which they take place, and the course which they im-
part to the food, are as follows :
   The alimentary bolus or morsel, on entering the  cardiac
orifice, turns to the left, follows the line of the great  cur-
vature of the stomach toward the pylorus, returns in the
line of the smaller curvature, makes its appearance again
at the cardia, and then descends, as  before, to the great
curvature, to  undergo similar revolutions till digestion be
completed.   Each revolution occupies about  from one to
three minutes, and its rapidity increases  as  chymification
advances.
   In treating of muscular action in the former volume, I
pointed out (p.  122) the necessity of  the  co-operation  of
a nervous stimulus to produce the result; and remarked
that there are two kinds of muscles, one  called the volun-
tary, which contract at the command of the  will, and  the
 other  the involuntary, over which the will has  no  control,
 and which act only  in obedience to their  own  peculiar sti-
 muli.   Of the latter description  are the muscular fibres of
 the stomach.   They contract when the stimulus of food is
 applied to them, but we can neither contract  nor relax
 them by an effort of the  will, nor are we even conscious
 of their existence.
    It is, indeed, fortunate for us that the necessary  motion* 
MUCOUS COAT OF THE STOMACH.          75
«oT the  stomach are not intrusted  to  our guidance, like
those of the hand or foot.   Supposing that we were to eat
three meals a day, the digestion of each requiring three or
four hours—and  that its  management  depended entirely
upon our superintendence—our whole  attention would be
required to the process, to the exclusion of every  other
duty, for ten or twelve  hours a day ; and every time that
our thoughts wandered  for a few  minutes, digestion would
stand still, and the  stomach be  disordered by the chemical
decomposition of the food which would ensue, so that it
would be impossible for us to dedicate any time either to
business or to social  enjoyment.   But  from all these in-
conveniences  we are entirely freed, by the stomach  being
placed under  the dominion of the involuntary nerves, and
so constituted as to perform its functions without any aid
from our will.
   The third and  innermost coat,  called the mucous or vil-
 lous, is that smooth, unequal, velvety membrane, of a red-
 dish white or pale pink  colour,  which lines the internal
 surface of the stomach.   From being of much greater ex-
 tent than the other two coats, its  surface is thrown into
 ruga, plica, folds, or wrinkles, which are simple in man,
 but very marked in  some animals, as seen  familiarly in
 tripe.   The subjoined wood-cut,  from the Library of Use-
 ful Knowledge, will give some notion of their appearance.
 Near the pyloric  orifice the villous coat is doubled on itself,
lous coat is constantly covered with a very thin transpa-
rent viscid mucus, and its folds are always best seen in
fthose who die suddenly.  After disease when the stomach
is relaxed, they frequently disappear. 
78    N1RVE3 AND BLOODVESSELS OF THE STOMACH.

  In addition to the folds just described, the mucous coat
contains a great number of spheroidal glandular bodies or
follicles, some  of  them scarcely  larger than pin-heads,
which  lie immediately  beneath  and almost incorporated
with it, and which are  most  numerous near the pylorus.
Physiologists are not entirely agreed whether the fluid se-
creted  by these follicles be the gastric juice, or merely the
mucus already referred  to as lubricating the internal sur-
face of  the stomach.   The latter, however, is the opinion
generally entertained, and the one  which is supported, as
we  shall afterward see, by the strongest evidence ;  the
gastric juice being, in fact, secreted directly from the ca-
pillary  or hair-sized vessels in which the minute branches
of the arteries terminate.
  Of  the nerves  and bloodvessels supplying the  stomach
it is unnecessary to say much.   We shall afterward have
occasion to notice the  former at some length, and to the
general reader the origin and distribution of the blood-
vessels are as unimportant as  they would be  difficult of
comprehension;  for the nature of the  red blood is  the
same  by whatever artery it  is supplied, and that of the
dark blood the same by whatever vein it is returned  to the
heart.   All that it  is important to know is, that the  sto-
mach  receives a large supply of blood by means of nume-
rous bloodvessels, the principal of which, as represented
on the wood-cut at page 69, follow  the  course of  GG the
greater and SS the smaller curvatures, and send off innu-
merable small branches  as they proceed  to  every part of
the stomach.  The coronary  artery and the pyloric branch*
of the hepatic or liver artery  go to the smaller curvature,
while another branch of the hepatic, and one from the sple-
nic or spleen artery, are ramified on the  larger curvature.
  In determining the uses of the internal or villous coat
of the stomach, we  must begin by considering separately
that of each of the elementary structures of which it is
composed—its follicles, bloodvessels, and nerves—and the
nature of the peculiar secretion, the gastric juice, to which
it gives rise.
  The follicles pour  out the bland viscid mucus which
lubricates the internal coat, and protects it in some degree
from sustaining injury by the immediate contact of irritating
bodies.  When  the follicles  are diseased,  as in  what is
called water-brash, they sometimes throw out a large  quan, 
            BLOODVESSELS of the stomach.          77

lity of a ropy transparent fluid, which oppresses the stomach
and impairs digestion.
  The bloodvessels of the stomach, like those of every
other part, are more or less active according to the energy
of its functions at the time.  In treating of the laws of exer-
cise  as applicable to all living parts,* I took considerable
pains to  point out the relation  which  the Creator has
established between the activity of every organ and the
energy of its vital functions.  When the brain is exercised
and  the  mind active,  an  augmented flow of blood takes
place toward  it to support its increased action, of which
the throbbing  temples  and fiery complexion of a man in a
paroxysm of rage are familiar examples.  When it is inac-
tive  and the  mind  indolent,  a  diminished flow of blood
occurs.  In like manner, when the muscles are called into
vigorous action, the circulation of the blood through them
is quickened, and their nerves are more than usually ex-
cited : greater waste of material is caused by the increase
of activity,  and more  blood, consequently, is required to
repair the waste and sustain their tone.  This law was so
well known to the older writers, that it was announced by
them as  an axiom in the very comprehensive  phrase,  Ubi
stimulus, ibi affluxus—" Wherever a stimulus  is, there is
also an afflux."
  The stomach  forms  no  exception  to this general law of
the  animal economy.   When it is  empty  and  idle, it is
contracted upon itself into comparatively small bulk, and
its bloodvessels become shortened and  tortuous in a corres-
ponding  degree.   The result is both a diminution  of their
calibre and a slower  circulation through  their  branches.
But when the stomach is  full and active the bloodvessels
have free scope, their tortuosity  disappears, their diameter
enlarges, and the circulation through them becomes quicker,
and fit for the rapid secretion of the mucous and gastric
fluids in the quantities which we have seen to be required
for  the  fulfilment of  digestion.  Accordingly,  when  the
latter process is  going on, the small  arterial branches
ramified  on the mucous  coat of the stomach  become so
multiplied and distended, as to impart to it a deeper  red
 colour than it has when the stomach is empty.   The in-
 creased  afflux of red or arterial blood to the stomach during
 digestion is not merely inferred from the analogy of  other
  * Principles of Physiology, 10th edition, &c, pp. 153, 192, and 302.
                           7* 
7S
NERVES OF THE STOMACH.
 organs.  Many opportunities have occurred of ascertaining"
 the fact; and, as I shall have occasion to  mention, Dr.
 Beaumont very often saw it take place.
   A corresponding change occurs in the  veins of the sto-
 mach during digestion.  Their diameter becomes enlarged,
 their course more straight, and the current of blood through:
 them  more rapid.   As the minute or capiUary extremities
 of the arteries open upon the inner surface of the stomach,
 and there exhale a fluid  secretion, so the corresponding
 venous capillaries likewise open upon the same surface, and
 inhale  or absorb  fluid, which they carry into the general
 circulation.  The rapidity with'which this absorption some-
 times takes place is almost incredible ; for a large draught
 of water may be thus taken up in a few minutes.  Fluids
 mixed with camphor or  other strong-scented  substance
 have  been given to animals as an experiment, and,  on
 killing them shortly afterward, the peculiar smell has been
 detected in the blood.  Most liquids are thus not digested,
 but simply absorbed.
   Rapid, however, as the process is, poisons which  enter
 the system by absorption do not act by any means so in-
 stantaneously as  those which directly affect  the  nervous
 system.
   In regard  to the peculiar influence which each of the
 nerves ramified on the stomach exercises on its functions,
much difference of opinion still prevails.   We may,  how-
ever, gather some useful notions by adverting to the  diffe-
rent sources whence they are derived, and comparing  these
with the purposes for which we know from  analogy that
different kinds of nerves are  required.
   Strictly speaking, the  nervous filaments supplied to the
stomach proceed from three distinct sources, and may be
held to fulfil as many distinct  uses.   In apparent accordance
with this, we observe three,  if not four, distinct classes of
 operations going on in that organ, each of which may, from
 analogy, be presumed to require  a distinct nerve for  its
performance.   These are, first, the pleasurable conscious-
 ness attendant on the presence of wholesome  food  in a
 healthy stomach, and which  becomes painful and disagree-
 able when the stomach is diseased or the food of improper
 quality; secondly, the peristaltic or muscular motion which
 commences the moment food is swallowed, and continue*
 till digestion  is completed ;  and, lastly, the  different pro* 
       DIFFERENT USES OT THE STOMACHIC NERVES.    79

Cesses of circulation, nutrition, secretion, and absorption,
which go on in the  component tissues of the stomach and
support its life.   To these ought perhaps to be added the
sensation in which  the feeling of appetite originates, and
which  we  have already  seen to be  connected with the
pneumogastric nerve.  But as it is still uncertain whether
it and the first of the three  now named may not be modifi-
cations of the same thing, I shall not insist on considering
them as different.
  Although we cannot  state positively  what particular
nerve presides over each of  these functions, it  may be
mentioned  that strong  presumptive  evidence has  been
adduced, particularly by Brachet, to show  that the pneumo-
gastric* nerve is charged with the involuntary motions of
the stomach, as well as  with the sense of  its condition.
Food being the  natural stimulus of that  organ, as light is
of the eye, its presence alone, without and even against the
will, suffices to produce the contraction of its muscular coat;
and, accordingly, the more stimulating the food, the more
rapid and vigorous is the  muscular contraction which it
excites.  So far, indeed,  do the stomachic nerves respond
to their own stimuli, that, if nauseous  or other irritant and
indigestible substances  be swallowed, the action of the
muscular coat becomes so violent as to excite sympatheti-
cally the simultaneous contraction of the diaphragm and
abdominal muscles, to aid in their immediate expulsion by
vomiting; and  this  is the reason why  such substances are
in common use as emetics.
  Magendie doubts whether  these  movements are in any
measure dependent upon nervous influence ; but the fact of
their being so  seems to be proved by the experiments of
Gmelin and Tiedemann, who found them constantly pro-
duced when the pneumogastric nerve was irritated either
by the scalpel or by the contact of alcohol.   Brachet also,
who examined the subject with great care, obtained similar
results ;  and  the only plausible  argument  against  their
conclusiveness consists in the double function which seems
thus to be assigned to a  single nerve—that of conveying
to the brain a sense  of the state of the stomach, and that of
imparting motion to  its muscular fibres.   Brachet, however,
turns this charge into an additional proof; for, on careful
  * From nvevpov, pneumon, a lung, and yaorep, gaster the sto-
mach, or lung and stomach nerve. 
80        USES OF THE PNEUMOGASTRIC NERVE.
 dissection,  it appears  that  the pneumogastric  nerve  is
 really a compound of two distinct sets of fibres, intimately
 connected no doubt in structure and in function,  but  each
 essentially distinct in  its origin, and so  far fitted for a
 peculiar office.
   When the pneumogastric or chief nerve of the stomach
 is tied  or cut  through, and its  ends  separated  so as to
 interrupt  the flow of nervous energy  toward that organ,
 digestion is either  entirely arrested or  greatly impaired.
 By the  greater  number of physiologists  this  result is
considered to arise from the consequent stoppage of  that
gentle and continued agitation of the alimentary mass in the
stomach which is necessary for  its thorough impregnation
with the gastric  juice, and which we have  seen to depend
on a stimulus communicated to its muscular coat by  that
nerve.   By some, however,  this explanation is  regarded
as incorrect.  Magendie and Dr.  Holland, for  example,
say that they have sometimes observed digestion continue
even after the division of the nerves  ; and that, when it
is retarded or impaired, the  result arises  only from  the
troubled state of respiration which the  cutting of the nerve
induces at the same time.   To this, again, it is answered,
that Dupuytren has divided the nerve below the part where
the pulmonary branches are given off, and,  consequently, left
respiration unimpaired ;  but that still digestion was arrested,
provided a portion of it  was cut out so as not to allow  the
current  of nervous  influence to continue :  for if the  two
ends of the nerve be left nearly in contact, it appears that
little interruption of its action takes place.
  Here, however, I cannot help observing, that, in drawing
conclusions from experiments of this nature, the constitu-
tional disturbance inseparable from the infliction of exten-
sive wounds on living animals is seldom  taken sufficiently
into account.  As regards digestion, for example, it is not
to be expected that that function can  be carried  on with
all the  regularity of health when the  animal is  suffering
severe pain, even although the stomach be  left untouched.
Brachet, indeed,  has shown, by direct  experiment,  that
 digestion may be interrupted almost as effectually by making
 an incision on the side or thigh, (provided it be sufficiently
 deep and  painful to excite  constitutional disturbance,) as
 by cutting the pneumogastric nerve itself.   This being  the
 case, we must not be loo hasty in considering every appa- 
USES OF THE PNEUMOGASTRIC NERVE.        81
rent result as inseparably and exclusively connected with
the individual  injury under our  notice at the time ;  we
must repeat  our observations under every variety of cir-
cumstances, and be careful to separate the accidental from
the essential, before admitting the inference to be correct.
It is, in fact,  this unavoidable source of vagueness which
so often renders  experiments on  living animals as incon-
clusive as they are inherently cruel.
   But after making every allowance on this account, the
experiments on digestion have been so  frequently repeated
and so extensively varied, that the general results  already
noticed may safely be regarded as demonstrated.   On all
hands, accordingly, the necessity of the co-operation of the
nervous energy in effecting it is admitted ; for no one se-
riously denies the fact, that retardation or total cessation
of digestion ensues, when the flow of the nervous fluid to-
ward the stomach is prevented by the division and separa-
tion of the cut ends of the pneumogastric nerve, or by the
operation of narcotics and the other disturbing causes already
alluded  to.   It is true that the mode in which the nerve
acts is not yet  ascertained, although the fact of its neces-
sary co-operation is rarely disputed.   As, however, the di-
rection of a current of galvanism to the cut end of the nerve
next the stomach suffices to re-establish digestion after that
process  has been suspended by the interruption of the ner-
vous influence consequent on its  division, we may reason-
ably infer  that, in the healthy state, the nerve merely trans-
mits to the stomach a stimulus or energy generated for the
purpose either  in the  brain or in the spinal marrow and
ganglia—that the nerve, in short, acts only as a condutor,
and does  not originate  the influence  which it evidently
imparts.   In several of Brachet's cases, indeed, as well as
in those of Tiedemann, the continued irritation of the  cut
end of the nerve proved sufficient to carry on digestion to
a certain point, by affording, in another way, the necessary
stimulus to the muscular contractions of the  stomach :  for
in all these experiments  digestion was found to have  ad-
vanced almost in exact proportion to the degree of admixture
which had been effected of the food with the gastric juice
—an admixture now ascertained  to be produced chiefly by
the contractile power of the stomach itself.
   The  muscular contractions of the  stomach being thus
under the guidance of the pneumogastric nerve, what are 
82         USES OF THE SYMPATHETIC NERVE.
called its vital functions—those by which its life is sustain-
ed—viz., circulation, nutrition,  secretion, and  absorption,
are generally considered to be carried on under the influence
of the great sympathetic or ganglionic nerve, so called from
its v«ry extensive ramifications being supposed to bring the
different parts of the system into relation with each other,
and  which, accordingly, is found to exist in animals that
have  neither brain nor spinal marrow, nor nerves  of volun-
tary motion.  In  man, however, the sympathetic nerve'
receives filaments from the sentient or feeling part of the
spinal marrow, probably for the purpose of connecting more
intimately the organic with the higher functions of animal
life.   But as much obscurity still prevails on  this subject,
and, moreover, we have no direct control over the  action of
the ganglionic nerves, I shall not detain the reader with any
conjectural discussion, but rather request his attention  for
a moment U the circumstance that it is through the medium
of the nervous  communications above hinted at  that the
very remarkable influence which all must have experienced
and observed as constantly exerted by the  mind and sto-
mach on each other, is kept up—an influence so powerful
in its effects on both bodily and mental health,  as to require
special notice  when we shall treat of the practical applica-
tion of the present exposition.
  The importance of the nervous agency in effecting diges-
tion has been  denied, because we are not conscious of the
presence of food in the stomach.  B ut in health the want
of such consciousness is aprivilege, and not a defect; and it
has been admirably pointed out by Dr.  Southwood  Smith*
that, in  possessing, as we do, the distinct consciousness of
a pleasurable feeling  in the stomach after  indulging in a
suitable meal,  we have all that is desirable for either utility
or enjoyment.   If we were aware of the presence of every
portion  of food  v/hiph the stomach contains,  and of the
changes occurring in each, our attention would be so dis-
agreeably and  unprofitably  taken up, that we would pray to
be delivered from the annoyance.   Where,  however, from
disease or the  food being inappropriate, the stomach is  in-
jured by what is eaten, consciousness  then  becomes pain-
ful for the express purpose  of warning us that mischief has
been done, and that  we must take means for its  removal.
In some kinds of dyspepsia, indeed, the sensibility becomes
            » Philosophy of Health, voL i., p. 80. 
       RELATION OF NERVES TO UNDIGESTED FOOD.    "83

exalted to an extraordinary degree.  Barras, who suffered
intensely from this cause, says of himself '• the sensibility
of the stomach increased  to a surprising extent ;  instead
of organic it became animal, to use the expression of Bichat.
Everything which took place in the principal organ of di-
gestion became as palpable to sense as if it had taken place
on the organ of touch, and the  presence of aliment was per-
ceived as clearly as if it had been under my hand."*
  The nerves of the stomach, it ought to be remarked, have
a direct relation to undigested but digestible substances ;
or, in other words, undigested  food forms their natural and
appropriate stimulus.  In consequence of this arrangement,
when any body incapable of digestion is introduced into its
cavity, distinct uneasiness is speedily excited, and an effort
is soon made to  expel it  either upward by the mouth  or
downward by the bowels.   It is in this way that bile in the
stomach excites nausea,  and that tartar  emetic produces
vomiting.  The nerves of the bowels, on the  other hand,
are constituted with relation to the presence of digested food,
and, consequently, when anything escapes into them from
the stomach  in an undigested state,  it becomes to them a
source of irritative ex«itement; and hence the colicky pains
and  bowel-complaints which so commonly attend the  pas-
sage through the intestinal canal of such undigestible  sub-
stances as fat, husks of fruits,  berries, and cherry-stones.
   Such, then, are the component parts of the  stomach, and
such the uses which they individually fulfil ; but before we
can  consider them in their combined form,  there  is still
another agent, and an important one in digestion, which has
already been repeatedly named, and  which, though not  a
portion of the stomach, yet plays too conspicuous a part in
its operations not  to require some separate notice—the  gas-
tric OR STOMACH JUICE.
   The existence  of a solvent fluid in the stomach has long
been  known  and its uses suspected ;  but  for  our  first
accurate acquaintance with its propensities  and  mode of
action we are indebted chiefly to the sagacity and persevering
zeal of Spallanzani, who investigated the subject with great
care and success about the middle of last century.   Con-
sidering the peculiar difficulties by which the  inquiry is
 surrounded, it i3 offering  no trifling homage to that distin-
guished observer  to say, that, by means of numerous, varied,
             * Cyclop. Pract. Med., voL ii., p. 635. 
 84    SINGULAR CASE OF WOUND IN THE STOMACH.

 and well-devised  experiments on  man  and  animals, he
 succeeded in overcoming most of the obstacles which had
 baffled the ingenuity of his predecessors, and in obtaining
 results, the general accuracy  and importance of which are
 now appreciated  more and more highly, in proportion as
 our knowledge advances and opportunities  present them-
 selves of bringing them to the test  of experience.
   It is rarely, indeed, that we can actually see what  is going
 on in a healthy stomach ; but in a few instances this advan-
 tage has been enjoyed, and turned to account in investiga-
 ting the phenomena of digestion.  By far the most  instruc-
 tive example of this kind which has  ever occurred, came
 under the  observation of Dr.  Beaumont  of the American
 army ; and as that gentleman eagerly embraced the oppor-
 tunity so unexpectedly afforded him of testing the prevailing
 doctrines  by a series of experiments, continued during a
 period of several years, and  under various  conditions of
 health and external circumstances, I  shall so frequently
 have occasion to refer to his  observations, that it  will be
 useful to give a brief outline of the case before entering
 farther  upon the  subject, in order that the  reader may be
 enabled to judge for  himself what weight  is due  to Dr.
 Beaumont's evidence on any disputed point.
   Dr. Beaumont, while stationed  at  Michillimackinac, in
 the Michigan territory, in 1822, in the military service of
 the United States, was called upon to take charge of Alexis
 St. Martin, a young Canadian of eighteen  years  of age,
 good constitution and robust  health, who was accidentally
 wounded by the discharge of  a musket on 6th June, 1822.
   " The charge," says Dr. Beaumont, " consisting of pow-
der and duck-shot, was received in the left side, at the
distance  of one yard from the muzzle of the gun.  The
contents entered  posteriorly,  and in an oblique direction,
 forward and inward ; literally  blowing off integuments and
muscles to the size of a man's  hand,  fracturing and carrying
 away the anterior half of the sixth rib, fracturing the fifth,
 lacerating the lower portion of the left lobe of the lungs, the
 diaphragm, and perforating the stomach."
   On the fifth day  sloughing  took  place ;  lacerated por-
 tions of the lung and stomach  separated, and  left a perfora-
 tion into the latter,   " large  enough to' admit the  whole
 length of the middle finger into its cavity ; and also a pas-
 sage into the chest half as largo as his fist.'"   Violent fever 
LEAVIKG A PERMANENT OPENING INTO ITS CAVITY,  85
and  farther sloughing ensued;  and for seventeen  days
everything swallowed passed out through the wound, and
the patient was kept alive chiefly by nourishing injections.
By and by the fever subsided, the wound  improved in ap-
pearance, and after the fourth week the appetite became
good, digestion regular, the evacuations natural, and the
health of the system complete.   The orifice, however, never
closed;  and at every dressing the contents of the stomach
flowed out, and its coats frequently became  everted or
protruded so far as to equal  in size a hen's egg, but they
were always easily returned.  The  above figure exhibits
the appearance of the wound  after it was healed.   The
circumference of the wound, E E E L, extended to about
twelve inches ; and the opening into the stomach, AAA,
nearly in its centre, was about two inches below the  left
nipple F.   The folds of the villous coat are visible at B C.
   Some months after,  St. Martin suffered extremely from
the death and  exfoliation of portions of the injured ribs and
their  cartilages, and his life was  often in jeopardy  ; but,
through the skill and unremitting care with which he was
treated  by Dr. Beaumont, he ultimately recovered, and in 
86     SINGULAR CASE OF WOUND IN THE STOMACH,

April,  1823, was going about, doing light work and rapidly
regaining strength.
  On 6th June, 1823, a year from the date of the accident,
the injured parts were all sound, except the perforation into
the stomach, which was now two and a half inches in cir-
cumference.  For  some months thereafter the food could
be  retained only by constantly wearing a compress and
bandage; but  early in winter  a small fold or doubling  of
the villous  coat began to appear, which gradually increased
till  it filled  the  aperture and acted  as a valve, so as com-
pletely to prevent any efflux from within, but  to  admit  of
being easily pushed back by the finger from without.
  Here,  then, was an admirable  opportunity  for experi-
menting on the subject of digestion, and for observing the
healthy and undisturbed operations of nature free from the
agony of vivisections, and from the sources of fallacy in-
separable from operating on animals.  Dr. Beaumont was
sensible of its value, and accordingly pursued his inquiries
with the most praiseworthy  perseverance and disinterested-
ness.  Having been fortunate enough to obtain a copy of his
work, I shall not hesitate to make free use  of its contents.
  Dr. Beaumont began his experiments in May, 1825, and
continued them for four or five months, St. Martin being
then in high health.  In the autumn St. Martin  returned
to Canada, married, had a family, worked hard, engaged as
a voyageur with the Hudson's Bay Fur Company, remain-
ed there  four years, and was then engaged, at  a great ex-
pense, by Dr. Beaumont to come and reside near him  on
the Mississippi, for the purpose of enabling him to complete
his  investigations.   He came accordingly in August, 1829,
and remained till March, 1831.  He then  went  a second
time to Canada, but returned to Dr. Beaumont in Novem-
ber, 1832, when the experiments were once more  resumed,
and continued till March, 1833, at which time he finally left
Dr. Beaumont. He now enjoys perfect health, but the orifice
made by  the wound remains in the same state as in  1824.
  Dr. Beaumont describes the aperture in St. Martin's sto-
mach as being situated about three inches to the left of the
cardia, near the left  or superior termination of the  oreat
curvature.  When the stomach was nearly empty, he was
able to examine its cavity to the depth of five or six inches
by artificial distention.  When it was entirely  empty, the
stomach  was always contracted on itself, and the  valve 
    LEAVING A PERMANENT OPENING INTO ITS CAVITY.  87

generally forced through the orifice, together with a portion
of the mucous membrane equal in bulk to a hen's egg.
After sleeping for a few hours on the left side, the protruded
portion  became so much  larger as  to spread " over the
neighbouring integuments five or six inches in circumfer-
ence, fairly exhibiting the natural ruga, villous membrane,
and mucous coat, lining the gastric cavity.  This appear-
ance is almost invariably exhibited  in the morning before
rising from bed."   Such was the very favourable subject on
whom Dr. Beaumont's observations and experiments were
made, and such were the numerous opportunities which he
enjoyed for repeating  them and verifying their  accuracy.
Having given this outline, we now return to the conside-
ration of the gastric juice, on  the  origin and qualities of
which it removes any uncertainty which previously existed.
  In treating of the properties of the gastric juice, I shall,
on all disputed points, give a decided preferencfe to the ob-
servations of Dr. Beaumont over those of any other physio-
logist ;  because, although a few  cases have occurred in
which, from external wounds, direct access has been given
to the interior of the  stomach,  and Richerand and others
have availed  themselves of the opportunities thus afforded
of adding to  our knowledge of  the digestive process, still,
in most of them  which have been recorded, the patients
were  a  comparatively  short time  under  observation, and
were  not sufficiently re-established in  health to admit of
either extensive or conclusive  experiments being made.
Whereas, in  the case which Dr. Beaumont had the  good
fortune  to meet with, the  patient remained under his eye
for several years, and in the enjoyment of the most robust
health ;  so that ample time and opportunity were afforded
for every variety of experiments which reflection could sug-
gest, and for their subsequent repetition under such modi-
fications as seemed to be requisite for clearly distinguishing
the accidental from the constant and essential result.  In
addition to these reasons, it_ ought to be  added,  in justice
to the American physiologist, that, from the excellent judg-
ment with which he carried on  his investigations, and the
scrupulous care with which  he announces his results and
separates facts  from theory, it  is impossible  not to place
great confidence both in his  personal  qualifications as an
observer, and in  the general accuracy of his  statements.
Moreover, as he enjoyed the rare advantage of seeing what 
88           PECULIARITIES OF GASTRIC JUICE.
       he describes  to have taken  place  in the stomach during
       healthy digestion, his evidence comes before us with the
       strongest possible,claims on our attention.*
          The first disputed point which is conclusively settled by
       Dr. Beaumont is, that the gastric juice does not continue to
       be secreted between the intervals of digestion, and does not
       accumulate to be ready for acting upon the next meal.   By
       inducing  St. Martin to fast for some hours, and then plac-
       ing him with the opening in the left side exposed to a strong
       light, so as to give a distinct view  of the cavity of the sto-
       mach, Dr. Beaumont found its only contents to consist of
       a little viscid and occasionally slightly acidulated mucus
       mixed with saliva, and  in  no instance did he perceive any
       accumulation of the proper gastric juice.   The same results
       had, indeed, been obtained by Tiedemann and other physio-
       logists before the publication of Dr. Beaumont's memoir ;
       but the evidence of the latter is so much more direct and
       incontrovertible, that it  may  justly be regarded  as setting
       the question for ever at rest.
          Having proceeded so far, Dr. Beaumont next endeavour-
       ed to discover at  what  time the gastric juice begins  to be
       poured out, and under what  conditions its secretion is car-
       ried on ;  and here again ocular inspection afforded him sa-
       tisfactory results
         * I cannot help thinking that, if St. Martin be still alive, which is    \
       most likely, some effort should be made either by the government
       or by a public subscription, to bring him over to this country, and,
       under the  direction of a competent committee, subject him to such
       farther experiments as may be necessary to complete the investiga-
       tion.  A similar opportunity may never again occur, and it would,
       therefore,  be a disgrace to the science of the nineteenth century to
       allow it to pass unimproved.  In a former edition I suggested that
       the Royal  Society should take the necessary steps for this purpose ;
       but they, it appears, want funds.  At the Newcastle Meeting of the
       British Association for the Promotion of Science, in 1838, a commit-
       tee recommended a grant of £200 from the general funds in aid of
       this object ; but at the suggestion, it is said, of the noble president,
       who considered such inquiries " disgusting," the recommendation
       was unfortunately negatived ! If my suggestion shall ever be acted
       upon, special care should be taken not to injure St. Martin's health
       by withdrawing him entirely from his accustomed diet and mode of
       life, otherwise the whole value of the experiment may be lost—the
*       object being to ascertain the laws and conditions of hkalthy diges-
       tion.  In throwing out this suggestion, I need scarcely add, that I
        am far from undervaluing what Dr. Beaumont has accomplished,
        and that I  consider it no disparagement to him to say, that  he has
        left some subjects of interest connected with the inquiry still unde-
        termined. 
          MODES OF OBTAINING GASTRIC JUICE.        89

  It has already been remarked, that, on pushing back the
valve which filled up  the  opening into  the  stomach, the
cavity within became visible to a considerable extent; and
that when St.  Martin lay over for a time on the left side,
a portion of the villous coat, large enough to exhibit several
inches of its surface, generally protruded.   Owing to these
circumstances,  Dr. Beaumont could  easily observe what
changes occurred, both when food was swallowed  in the
usual way,  and when it was introduced at the opening left
by the  wound.   Accordingly, on examining the surface of
the villous coat with a magnifying  glass, he perceived an
immediate change of appearance ensue whenever any ali-
ment was brought into contact with it.   The action of the
neighbouring bloodvessels was  instantly  increased, and
their branches  dilated so as to admit the red  blood  much
more freely than before.  The colour of the  membrane con-
sequently changed from a pale pink to  a deeper red, the
vermicular or  worm-like motions of the stomach became
excited, and innumerable minute lucid points and very fine
nervous and vascular papillae could be seen  arising from the
villous coat, from which distilled  a pure,  colourless, and
slightly viscid fluid, which collected in  drops on the very
point of the papilla? and trickled down the sides of the sto-
mach till it mingled with the food.  This afterward proved
to be the secretion peculiar to that organ, or, in other words,
the  true gastric juice; the rnucous  fluid  secreted  by the
follicles, which some have mistaken for it, is not only more
viscid, but wants altogether the acid character by which it
is generally distinguished.
  Pursuing his experiments, Dr. Beaumont then found that
the contact, not only of food, but of any mechanical irritant,
such as  the bulb of a thermometer, or other indigestible
body, invariably gave rise to the  exudation of the gastric
fluid from these  vascular  papillae;  but  that  in the  latter
cases the secretion always ceased  in a short time, as soon
apparently a-3 the organ could ascertain that the foreign body
was one over which the gastric juice had no power.   But
the small quantity obtainable in this way is perhaps  more
pure and free from admixture, and, therefore, better adapted
for examination, than any which can be produced under any
other circumstances.
   Various  methods have been employed for procuring the
gastric fluid in a state of purity.   Pieces of  dry sponge, en-
                          8* 
90
ELEMENTS OF GASTRIC JUICE.
closed in a small hollow perforated ball with a string attach-
ed to it, have been swallowed both by man and by inferior
animals, and afterward withdrawn to have the juice express-
ed from them.   In some  instances the stomachs of crimi-
nals and animals killed after fasting have  been opened, and
the secretion collected.   At other times the juice has  been
procured by voluntary or artificial vomiting.  None of these
methods is equal to that employed by Dr. Beaumont; but
of the three  the first is unquestionably the best, because,
although no gastric juice previously exists, the very contact
of the ball excites the secretion of a quantity sufficient to
moisten the sponge.  In the second mode  of proceeding,
any  portion of juice secreted in consequence of a stimulus
applied after the stomach is open, must necessarily be very
small, and rendered impure by the large admixture of mucus
which it will contain; while by the third method, as the
gastric  juice does not exist ready made in the  stomach,
either none but  merely mucus will be procured, or it will
be expelled mixed with  the food  or substance which had
previously  elicited its secretion.
  Gastric juice, in its purest form,  and unmixed with any-
thing except  the small portion of mucus from which it can
never be obtained entirely free, is described by Dr. Beau-
mont to be a clear transparent fluid, without smell, slightly
saltish, (probably from the admixture of  mucus,) and very
perceptibly acid.   Its taste, he says, resembles that of thin
mucilaginous water, slightly acidulated with muriatic acid.
It is readily diffusible in water, wine, or  spirits,  and effer-
vesces slightly with alkalis—a direct proof of its acid na-
ture.   It coagulates albumen, and is powerfully antiseptic,
checking the  progress of putrefaction in  meat.   When
pure it will keep for many months,  but when diluted  with
saliva it becomes fetid in a few days.  According to  Pro-
fessor Dunglison,  to whom  some  was submitted by  Dr.
Beaumont for analysis, it contains free muriatic and acetic
acids—phosphates and muriates with bases of potassa, soda,
magnesia, and lime—together with  an animal matter solu-
ble in cold but  insoluble  in hot water.   Tiedemann and
Gmelin, again, describe it as composed principally of mu-
riatic and acetic  acids, mucus,  saliva, osmazome, muriate,
and sulphate of soda, with little or no albumen ; and, ac-
cording to  Nthe same physiologists,  the proportion of  acid
is always  greatest when  vegetables or  other substances 
THE GASTRIC JUICE A SOLVENT OF FOOD.      9t
of difficult digestion constitute the chief part of the diet.
Other chemists give an analysis somewhat  different from
either of these ; a circumstance which was, indeed, to be
expected, considering not only the differences caused by
variations of diet and of health, but also the necessarily diffe-
rent degrees of purity of the fluid submitted to examination.
  The most remarkable property of the gastric juice  is
unquestionably the power which it possesses of dissolving
and reducing to the appearance of a soft thickish fluid mass
everything in the shape of food which is submitted to its
action—while it  exerts no perceptible influence on living
or inorganic  matter;  for, so far as is yet known, nothing
which is  not organized, or which  is still alive, can serve
as nutriment for  the animal frame.   Water is  the only in-
organic  body which is taken into  the  system for its own
sake, and all mineral and other inorganic productions enter
it as component  parts of previously organized substances
of either an animal or a vegetable nature.  To a great ex-
tent, indeed, vegetation seems to be merely a process for the
conversion of inorganic matter into a proper nutriment for
the support of animal life ;  and many species of animals
seem in their turn to be little else than living machines for
the conversion of vegetable substances into a nutriment fit
for other species by which they are intended to be devoured
It is true that, in some parts of South America, the natives,
pressed by  want, consume  quantities  of a  soft  unctuous
clay, which  is, of course, destitute of organization; but
as there is every reason to believe that no nourishment is
derived from it, and that it merely serves to allay the pang3
of hunger, such  instances form no exception of  the gene-
ral rule.
  It would have been easy for the Creator to bestow such
a structure on all animals, as to make them subsist entirely
on vegetable aliment.  But the arrangement which He has
seen fit  to  adopt  is  the source  of an  infinitely  greater
amount of active enjoyment that what could otherwise
have existed.  Had there been no beasts of prey, the world
would soon have been overrun with herbivorous  creatures
to such an extent, that their numbers would speedily have
become excessive in reference to the possible supply of
food, and there would  have  been infinitely more suffering
from starvation and disease, than what actually arises out
of their existing relation to  each other.  On the present 
 92    ACTION OF GASTRIC JUICE ON THE STOMACH.

 plan there is ample food and enjoyment for all;  and when
 the time does  arrive when one  animal  must become the
 prey of another, the deprivation of life is  in most cases un-
 foreseen,  and the suffering which  attends it is in general
 only momentary in duration.   There is thus both complete
 enjoyment of life while it lasts, and a great additional field
 opened for the  support  of an immense  class of animals,
 which, with their present constitution, could not otherwise
 have existed at all.*
   The gastric juice, as already remarked, has no power
 over living animal matter—a most wise and admirable pro-
 vision, since  otherwise it would at once have attacked and
 destroyed the very organ which  produces  it.   This is the
 reason why certain worms are able  to exist in the stomach
 of man and other animals ; and if it were  possible for an
 oyster swallowed directly from the shell to continue to live,
 it would  also effectually resist every attempt at digestion.
 But it, in common with most other beings, soon perishes
 in circumstances so foreign to its habits ;  and when once
 dead, the gastric juice assumes  the mastery,  and speedily
 converts it into chyme.
   If anything could have opened Monte"gre's eyes to the
 fallacy under which he laboured in considering the  gastric
 juice as almost identical with saliva, the circumstance we
 are now to mention would have sufficed.   When a person,
 previously in good health, dies by a violent death, or when
 an animal is  killed soon  after a meal, it very often happens
 that, on opening the body after an interval of  some hours,
 the stomach  is found to be eroded, and its contents poured
 into the cavity of the  abdomen, precisely as if a hole had
 been  formed in it by ulceration.  It was long before the
 reason of  this was discovered  ; but at length it was ascer-
 tained to  arise from the action of gastric juice {the abun-
 dant secretion of which  was provoked by the immediately
preceding meal)  upon the substance of  the stomach, now
 subjected to its power  from being  deprived of life.   This
 fact has been so often  verified, that it is by all admitted as
 incontrovertibly true.f   If, therefore, the gastric juice be
  * The reader will find the same line of argument most eloquently
 and successfully pursued by'Dr. Buckland in his admirable Bridge-
 water treatise on " Geology considered with reference to  Natural
 Theology," which appeared subsequently to the first edition of thii
 volume.
  f Professor Carsewell, of the London University, has rendered an 
GASTRIC JUICE ANTISEPTIC.             93
 merely saliva  and mucus, we might expect to find after
 death distinct traces of similar results from the contact of
 saliva within the mouth or gullet; bufrtere no such erosion
 is ever witnessed, nor, as Montegre himself admits, does
 saliva exert any solvent power whatever over dead animal
 matter out of the body.   These facts appear quite sufficient
 to convince any unprejudiced mind.
   The power  of  coagulating milk, and albumen or  the
 white of eggs, is  another  remarkable property of the gas-
 tric jmce—and one so familiarly known, that in  dairies an
 infusion of the  stomach of the calf is in common use, under
 the name of runnet or rennet, for curdling milk.  In infants,
 also,  we know  that the nurse's milk has scarcely reached
 the stomach before coagulation takes place;  a fact which
 leads many experienced mothers to infer that the infant is
 already suffering from acidity, and to counteract the sup-
 posed evils by repeated   doses  of magnesia—which, of
 course, do more harm than good.  The coagulation of milk
 in the stomach is  so  far from being a morbid process, that
 milk cannot be  properly digested without it.  By the separa-
 tion and absorption of the fluid whey, the  curd is reduced
 to a proper consistence for being acted  upon, both by  the
 gastric juice itself and by the contractions of the muscular
 coat.
  The gastric juice is also powerfully antiseptic;  that is to
 say, it prevents animal substances  from becoming putrid,
 and even renders  sweet such as have advanced a conside-
 rable way toward  putrefaction.   Dr. Beaumont  mentions
 that the pure juice will keep unchanged for  almost  any
 length of time ;  and, according to Spallanzani, meat may be
 preserved in it  without  taint for five or six weeks, or even
 longer.  This  antiseptic  tendency of the gastric fluid  ac-
 counts for the circumstance that little or no mischief results
from  the common practice among epicures, of not making
use of game till the putrefactive process is advanced farther
 than is agreeable to the1 palates of  the uninitiated.

essential service to practical medicine, as well as morbid anatomy,
 t>y demonstrating, in an excellent paper published in the 34th  vo-
 lume of the Edin. Med. and Surg. Journal, that softening and ero-
 sion of the stomach,  considered by Broussais and  others as always
 results of inflammatory irritation during life, are generally caused
 py the digestive action of the gastric juice after death.  The essay
is well worthy of an attentive perusal: but it would carry me too far
 to notice it here at greater length. 
94    GASTRIC JUICE VARIES ACCORDING TO FOOD.

   The qualities of the gastric juice are so directly adapted
to the natural food of the animal, that flesh introduced into
the stomach of an ox or a sheep,  for example, undergoes
scarcely any change ; while vegetable food,  on the other
hand, remains equally undigested in that of a beast of prey.
Thus, " when a hawk or an owl has swallowed a small bird,
in the stomach of which have been seeds, these bodies are
not dissolved by  the gastric fluid,"* but pass through the
intestines unaltered.   Man, the dog, and some  other crea-
tures, possess the power of digesting all sorts  of aliment,
whether vegetable or animal, and  are hence  called omni-
vorous or all-eating ; but even in  them the relation which
the properties of  the gastric juice  bear  to the qualities of
the food chiefly or exclusively used is so close, that, when
a widely different kind is suddenly resorted to, indigestion
is the  almost inevitable consequence—because  then the
gastric juice has not had time to acquire its requisite adap-
tation to the new materials on which it has to act.   Hence
also the  danger  arising from  suddenly eating  a full  meal
after having been  long famished.  The stomach, accustomed
for a time  to the smallest quantity, is no longer able to pro-
vide gastric juice sufficient for the purposes  of digestion ;
and, being irritated  by continued craving, its secretions are
vitiated and its sensibility  exalted to such a degree as to
require  the wisest management to enable it to regain  its
healthy tone.
   Trie gastric juice of carnivorous animals differs even in
its chemical constitution from  that of the herbivorous ;  a
circumstance which accounts for the difference  observed in
their action.  In  the former, such  as that  of birds of prey,
serpents, and fishes, no free or uncombined acid can  be
detected, although it is invariably found  in the gastric fluid
of vegetable-eaters.   In crows and dogs, on the  other hand,
and such  animals as can live on either  kind of aliment, it
is never acid, except when they have  been fed chiefly  on
grain or plants.   In man the same relation has, by nume-
rous experiments, been ascertained to exist.
  But although, in every class of living beings, the gastric
juice is constituted with a direct relation to its natural food,
still its qualities may be so much  modified by a very gra-
dual change of diet, as to fit it for digesting aliment of a
  * Macgillivray's Description of the Rapacious Birds of Great Bri-
tlin, p. 24 
GASTRIC JUICE VARIES ACCORDING TO FOOD.
95
very dissimilar or opposite kind.   Thus, in the natural state,
the stomach of a sheep exerts scarcely any action on beef
or mutton ;  but if the change from the one kind of food to
the other be made  by  slow degrees, the gastric juice will
in the end become so essentially altered as to enable it to
digest  both.   In this  way, as  is  mentioned by Delabere
Blaine,* a horse at the Veterinary College was supported
for some time  by animal matter alone ; while others have
subsisted on dried fish  or  on milk.   It has been  shown
also, by John Hunter, Spallanzani, and others, that eagles,
falcons, owls, pigeons,  and  domestic fowls may for  a time
be fed on aliments altogether foreign to their natural habits.
But these facts only show  the extent to which Nature will
go, on  an emergency, for the preservation of life ; and  no
more indicate  the  equal fitness of both kinds  of aliment,
than the fact of some  men being able to stand for a few
minutes on their heads proves an inverted position to be
the natural attitude of the  human race.
   In consequence of this adaptation of the gastric juice to
the nature of the food,  it is obvious that sudden and extreme
changes from one kind of diet to another must be injurious,
because the stomach has not time to modify its secretions
sufficiently  to  meet the  altered  demand  made upon  its
powers.  This, accordingly, is one of the  reasons why so
much caution is used in bringing horses info condition after
having been for some time in the  pasture-field.   When
they have previously been on  dry food in the  straw-yard,
corn may be  given with greater safety: so that it is  the
change, not so much  in  quantity as  in kind  of aliment,
which causes the risk.   And on this  account, when a horse
is to be put upon hard food, after having been fed on grass
or other succulent vegetables, Blaine recommends, not only
that hay and corn should  be given in very small quantity
at first, but  that the hay should be moistened and the corn
mixed with bran  and  mashed;  by  which  means  having
acquired a greater analogy to grass, it will  be  more easily
acted  upon  by the gastric juice, which has been previously
adapted for green food.
   Even in man the gastric juice undergoes considerable
modifications, not merely according  to the kind of aliment
habitually used, but also according  to the time of life, the
 wants of the system, the season of the year, and the state of
           * Blaine's Veterinary Art, 3d edit., p. 247. 
96     GASTRIC JUICE VARIES ACCORDING TO FOOD.

the health ;  so that, while sudden and great changes from
one kind of diet to another are positively hurtful  on  the
one hand, absolute uniformity is not  less objectionable on
the other, because it leads  to so great  a uniformity in  the
quality of the gastric juice habitually secreted as to render
it  incapable of acting with due effect on any accidental
variety of food, to which a change of circumstances may
compel us.
  Many attempts have been made to ascertain to which of
the elements of the gastric juice its power is chiefly to be
ascribed, and  experiments have been  instituted on them
individually to discover which of them is most nearly analo-
gous to it in effect. 'From the general results, it  appears
that acetic acid (vinegar) and muriatic acid  have  a wider
range of influence, and produce solvent effects more closely
resembling those of gastric juice, than any  other known
substances.   Both of these acids, it will be recollected, are
constituent  elements  of the gastric fluid ; and it has, in
consequence, been argued that to them it is indebted for
all its energy.   And, indeed, without laying too much stress
on this real or supposed analogy, it  is impossible  to over-
look the  well-known fact, that scurvy and a highly  alkaline
state of the system are generally induced by a diet  restrict-
ed for a long time to animal food alone, and are  prevented
or cured most easily by a free use  of lemon juice or of
vegetable matter, either fresh or fermented.  In these cir-
cumstances the vegetable acid is probably efficacious, both
by directly improving digestion and by combining with the
excess of the alkaline salts already existing in the  system.
It is worthy of remark, too, that in weak  stomachs acidity
is almost invariably induced by the use of vegetable food,
possibly to some  extent  for the very purpose of effecting
its digestion ; for it has  been ascertained beyond  a doubt,
that in herbivorous animals the gastric juice always con-
tains some free or uncombtned acid—and in man also, after
living much on vegetables for some  time.
   The necessity  of acid for the chymification of vegetable
food affords an explanation of the fondness which  the Ger-
mans  and  Dutch display for saur-kraut—or cabbage  in a
 state of  acetous  fermentation—and of its alleged  easy di-
 gestibility.   It explains also the general use  of vinegar
 along with salads, cucumbers, oysters, salmon, and other
 substances of difficult digestion, and shows that its utility 
        GASTRIC SECRETION VARIES FROM DISEASE.      97

is  not imaginary, but loudly proclaimed by Nature's own
acts.
  Another important principle, which Dr. Beaumont con-
ceives to be established by his numerous experiments, and
which forced itself upon him by degrees, is, that in health
THE  GASTRIC SECRETION ALWAYS BEARS A DIRECT RELA-
TION TO THE QUANTITY OF ALIMENT NATURALLY REQUIRED
by the system ;  so  that if more than this be taken, there
will  necessarily be too small a supply of the juice for the
digestion of the whole.  The principle  here laid  down is
in perfect harmony with the sympathy which we have seen
to exist between the  stomach and the rest of the body, and,
therefore, not only is highly probable in itself, but, if sound,
will prove a most valuable guide in the practical regulation
of diet.  The number of phenomena which  it explains, and
its general applicability to daily use, afford no small pre-
sumption of its  truth.  When, for example, we eat more
than the wants of the system require, indigestion  will fol-
low, because there will be more food in the stomach than
what the quantity of gastric juice provided is able to dis-
solve ;  the proportion of the juice secreted being in relation,
not to what we eat, but to the actual wants of the  system,
which, in the case supposed, we have  greatly exceeded.
Here a remarkable harmony will be perceived between  the
quantity of the secretion and the true indications and uses
of appetite  as  a guide to diet, explained in a preceding
chapter, (p. 38.)
   The gastric  secretion and the appearance of the villous
coat  undergo great  modifications during disease, and on
this  subject  also Dr. Beaumont's observations are highly
valuable ; because, instead of merely inferring, as others are
obliged to do, he enjoyed the privilege  of seeing  with his
eyes  what was actually going on.  In the course of his at-
tendance on St Martin he found that, whenever a  feverish
state was induced, whether from  obstructed perspiration,
from undue excitement  by stimulating  liquors, from over-
loading the stomach, or from fear, anger, or other mental
emotion depressing  or  disturbing the nervous system, the
villous coat became sometimes red and dry, and at other times
pale and moist, and  lost altogether its smooth and healthy
appearance.  As a necessary consequence, the usual  secre-
tions became vitiated? impaired, or entirely suppressed ; and
the  follicles from which, in  health, the  mucus which pro-
                           9 
 98        GASTRIC JUICE DEFICIENT IN DISEASE.

 tects the tender surface of the villous coat is poured out,
 became flat  and flaccid, and no longer yielded their  usual
 bland secretion.   The nervous and vascular papilla?, thus
 deprived of  their defensive shield, were then  subjected to
 undue irritation.  When these diseased appearances were
 considerable, the system  sympathized, and  dryness of the
 mouth, thirst, quickened pulse, and other symptoms  show-
 ed themselves ; and no gastric juice could be procured
 OR EXTRACTED EVEN ON  THE APPLICATION OF THE USUAL
 STIMULUS OF FOOD.
   These facts, if correctly observed,  are  of  extreme im-
 portance ; and, from  the  care  with which  Dr.  Beaumont
 pursued his  investigations, and  their accordance with the
 facts recorded by preceding physiologists,  I do not  think
 their general accuracy can be called in question.  The dry,
 irritated appearance of the villous coat, and the absence of
 the healthy gastric secretion in the febrile state, not only
 explain  at once  the want of appetite, nausea, and  uneasi-
 ness generally felt in the  region of the stomach, but show
 the folly of attempting  to sustain strength, by forcing the
 patient  to eat when food Cannot be  digested,  and  when
 Nature instinctively refuses to receive it.
   Before dismissing  this part of the subject, it may be re-
 marked, that the alleged sympathy of the stomach with the
 wants of the body  has been denied, because  the sense of
 hunger disappears  the moment food  is  swallowed, or the
 stomach is distended even with clay or saw-dust, although
 the actual wants of the  system cannot by possibility have
 been supplied in either case.  But these facts seem to me
 rather to justify the inference that a  sympathy does  exist.
 Hunger ceases when food is taken, simply because now the
'condition of  the stomach  is  in the desired relation to the
 state of  the body, and  the  nerves consequently feel and
 transmit this impression td the more distant parts.   In the
 other case, again, it ceases because the stomach cannot at
 first distinguish what is food from what is not ;  and, there-
 fore, when  distended, expresses content,  because  it feels
 satisfied that it has been  honestly dealt with, and got what
 it wanted.   But whenever it discovers the cheat, which it
 does in no long time, hunger returns, and can be properly
 appeased only by digestible substances.   Dr. Beaumont,
 indeed, expressly mentions, that, although  the gastric se-
 cretion  commences the   moment  any  indigestible  body 
EXPLODED THEORIES OF DIGESTION.         99
touches the mucous surface of the stomach, it invariably
ceases  soon after  discovering that  the substance  is one
over which it has no power—thus strongly confirming the
existence of the sympathy.  Here it may be also proper to
observe, that,  from the  frequent and  pointed  references
which I have  made  to  the  results obtained by Dr. Beau-
mont,  some of my readers have  imagined  that I claimed
for him the merit of the  original  discovery of  all  the
truths which his experiments tend to establish.   Nothing,
however, was  farther from my intention, and, accordingly,
on page 84 I  speak distinctly of his having eagerly em-
braced the opportunity  afforded  him of " testing the pre-
vailing doctrines "  on digestion;  and on page 88 and other
places I state  that  the  same  results had previously been
arrived at byTiedemann and other observers, but that  the
evidence in their favour  adduced  by Dr.  Beaumont was
"more direct  and incontrovertible," and,  therefore, more
conclusive, than theirs—a position wholly at variance with
any claim of discovery on his part.  Indeed, the utter ab-
sence of pretension in Dr. Beaumont's work is one of its
most pleasing  characteristics.

                     CHAPTER V.
            THEORY AND LAWS OF DIGESTION.
Different theories of Digestion—Concoction—Fermentation—Putre-
  faction—Trituration—Chemical solution—Conditions or  laws of
  digestion—Influence of gastric juice—Experiments illustrative of
  its solvent power—Its mode of action on different kinds of aliment;
  beef, milk, eggs, soups, &c—Influence  of temperature—Heat of
  about 100° essential to digestion—Gentle and continued agitation
  neeessary—Action  of stomach in  admitting food—Uses of its
  muscular motion—Gastric juice  acts not only on the surface of
  the mass, but on every particle which  it touches—Digestibility
  of different kinds of food—Table of results—Animal food most di-
  gestible-Farinaceous next—Vegetables and soups least digestible
  —Organs of digestion  simple in proportion to  concentration of
  nutriment—Digestibility depends on adaptation  of food to gastric
 juice  more' than an analogy of composition—Illustrations—No
  increase of temperature during digestion—Dr. Beaumont's sum-
  mary of inferences.
   Before  entering upon  the  consideration of the theory
of digestion which  naturally evolves  itself from the facts
expounded in the preceding chapter, it may be of advantage
to turn for a moment to the various theories which have
prevailed since the  subject first attracted the attention of
the learned. 
100        EXPLODED THEORIES OF DIGESTION.

  Hippocrates regarded digestion as a kind of concoction or
stewing; and many of his followers believed that it is ef-
fected in the stomach by the agency of heat alone, much
in the same way as food is  cooked over a fire.  It is quite
ascertained that heat favours  the process, but it is pure
absurdity to maintain that that agent alone will accomplish
digestion.
  Others of the older physiologists contended that chymi-
fication results from simple fermentation of the alimentary
mass, and referred to the gas disengaged during difficult
digestion as a proof that the process of fermentation goes
on.   But it is now demonstrated that  the  tendency  of
healthy digestion is rather to arrest than to induce fermenta-
tion, and that the latter takes place only when disease exists,
or when  more food  has been swallowed  than the quantity
of gastric juice secreted by the stomach is able to dissolve.
Moreover, the  products  of digestion and of fermentation
are so extremely different, that  it is  impossible to believe
them to originate from the same chemical action.
  The next theory which prevailed  considered  digestion
to be the result of the putrefactive process.   The single
fact, that the gastric juice not only arrests putrefaction, but
even restores to sweetness meat in which that process is
begun, is sufficient to  demonstrate the wildness  of  such a
supposition.
  Another set of physiologists imagined that trituration
would account best for  all the  changes occurring in the
food  during  digestion ;  and, consequently,  regarded the
chyme as a sort of emulsion formed by the intimate mix-
ture of the aliment with the juices of the stomach, just as
an emulsion is  formed by rubbing down almonds  in a mor-
tar.   The  advocates of this theory referred for proofs, not
only to  the contractile  motions  of the stomach  already
noticed,  but to  the  muscular  apparatus  for  trituration
which forms so remarkable a feature in the gizzard of gra-
nivorous birds.  But, in  adopting this conclusion, they
forget that in  birds the  triturating apparatus does not di-
gest, but serves, like the organs of mastication in man and
quadrupeds, merely to bruise the  grain on which the ani-
mal lives.  In birds, in fact, digestion begins only after the
trituration is finished.
   A more recent and much more accurate view of diges-
tion, is that which considers it  as neither more  nor less 
CONDITIONS REQUIRED FOR DIGESTION.      101
■than  a chemical solution  of  the food in the gastric juice.
This  theory is supported by a greater number of facts and
experiments  than any  other;  but, although  substantially
correct, it is perhaps too exclusive and limited in its princi-
ples.   It  is  true  that, by the  agency of gastric juice on
food  out of the body,  a change very similar to chymifica-
tion can be effected on it;  but when we remember  that
chyme, or  the result of real digestion, is  essentially the
same in its elementary or  component  principles, whatever
be the kind of food from  which it is formed—and that, as
yet, we  are   acquainted  with  no  purely chemical agent
which, if  applied to  different substances, gives rise to the
same uniform product—we shall be more willing to believe
that chymification is neither a purely mechanical  nor a
purely chemical  operation ;  but  the result of  a vital  pro-
cess,  to which both  mechanical  and chemical forces  con-
tribute, and which no  action or  combination of inanimate
matter can either exactly imitate or supersede.
   To enable  ourselves to appreciate correctly the nature
of digestion,  we must begin  by considering the conditions
essential for  its  performance, or without which it cannot
be carried on.
   The first  indispensable requisite is an adequate supply
of gastric juice, and its thorough admixture with every par-
ticle of the food on which it is to operate.  The second is
a steady temperature of about 98° or 100° Fahr ; and the
third is the  gentle and continued agitation of the alimen-
tary mass in  the stomach while digestion is going on.
   In  illustration of the influence of the first  condition, I
may refer to the experiments already mentioned as having
been  made by Spailanzani, Stevens, and others, to show
the solvent power of the  gastric juice  on food  even out of
the boay.  Spailanzani states that, when small portions of
well-masticated beef or mutton are placed in a vial with a
due proportion of gastric juice, and the requisite tempera-
ture and gentle agitation are  secured by placing the vial in
the arm-pit, the appearances  presented at the end of a few
hours are  extremely analogous  to  those observed in the
natural process of chymification; the  meat being in both
cases converted into the soft grayish mass of a pultaceous
consistence called chyme.
   Dr. Beaumont, who  was well  aware of the  importance
of  Spallanzani's  researches,  and of the almost  universal
                            9* 
 102      AN ADEQUATE SUPPLY OF GASTRIC JUICE.

 adoption of his views by succeeding physiologists till con-
 fidence in their  accuracy was for  a time shaken  by the
 bold  and  fallacious  assertions of Montegre,  felt that the
 opportunity afforded him by St. Martin's wound  for verify-
 ing  or disproving the experiments on which these views
 were  founded, was much too valuable to be  lost.   He
 therefore  entered upon a long series of investigations, of
 which the following is an imperfect, though I  hope instruc-
 tive, abstract:
   To  test the reality of the  solvent powers ascribed to
 the gastric juice, Dr. Beaumont  withdrew from St. Mar-
 tin's stomach about one  ounce of it, obtained after a se-
 venteen hours' fast,  by introducing  first a thermometer to
 induce the secretion, and then a gum-elastic tube to carry
 it off.  Into this quantity, placed in a vial, he introduced a
 piece of boiled recently-salted beef, weighing three drachms.
 He then corked  the  vial  tightly, and immersed it in water
 raised to the temperature of 100°, which he had previously
 ascertained to be the heat of the stomach when  the secre-
 tion was going on.  In forty minutes digestion had dis-
 tinctly commenced on the surface  of the beef.  In fifty
 minutes the fluid became quite opaque and cloudy, and
 the texture of the beef began to loosen and separate.  In
 sixty minutes chyme began to be formed.   In one hour and a
 half the muscular fibres hung loose  and  unconnected, and
 floated about in shreds.   In three hours they had diminished
 about one-half.   In five hours only a few remained  undis-
 solved. In seven hours the muscular texture was no  longer
 apparent;  and in nine hours the solution was  completed.
   To  compare the progress of digestion in  the natural
 way with these results, Dr. Beaumont, at the time of com-
mencing the experiment just described, suspended a piece
of the same beef, of equal weight  and  size, within the
stomach by means of a string.  At the end of the first
half hour it presented the same appearances as  the piece
in the vial ; but when Dr. Beaumont drew out the  string
at the end of an hour and a half, the beef had been com-
pletely digested and  disappeared,  making a difference of
result in point of time of nearly  seven  hours.  In both
the solution began on the  surface, and agitation accelerated
its progress, by removing the external coating of chyme as
fast as it was formed.  When the  experiment was repeat-
ed with chicken instead of beef, the solution  was slower, 
ACTION ON GASTRIC JUICE.
103
from the greater compactness of the chicken not allqwing
the gastric  fluid to penetrate  its  substance so readily.
Had the beef and chicken been masticated  before being
subjected to  experiment, the difference between them in
the rapidity  of digestion would probably have been less.
  To ascertain  still more accurately  the difference be-
tween natural and artificial digestion, (the one in and the
other out of the stomach,)  Dr. Beaumont put  twelve
drachms of  recently-salted boiled beef into a vial, with the
same number of drachms  of fresh  gastric juice obtained
through the opening of the stomach after a fast' of eighteen
hours ; and  then placed the vial in  a basin of water  on a
sand-bath, where he kept  it at the heat of 100° Fahr.,
and continued to agitate it gently.  Digestion soon com-
menced and went on uniformly for about six hours, when
it ceased.  One-half of the meat was then dissolved, and
the texture  of  the remainder loosened and tender—re-
sembling the same kind of aliment when ejected from the
stomach partly digested some hours after a meal, as  fre-
quently seen in cases of indigestion.   On weighing the
undissolved portion which remained after all action  had
ceased, six drachms and twelve grains of the beef were
found to have been digested by twelve drachms* or nearly
double its weight, of  gastric juice.  It thus appears that
a given quantity of gastric fluid can digest only a relative
proportion of meat ;  so that, when more is eaten  than
what there is juice sufficient  to dissolve, stomachic disor-
der must necessarily follow.  In this latter case Dr. Beau-
mont found that the addition of fresh juice causes digestion
to be resumed.
  To discover what influence would be  exerted  on  food
masticated, swallowed, and mixed with the gastric juice
in the usual way, and then withdrawn  from the  stomach,
Dr. Beaumont gave St. Martin an ordinary dinner of boiled
salted beef, bread, potatoes, and turnips, with a gill of pure
water for drink ; and twenty minutes afterward  drew off
through the  opening about a gill of the  contents of the
stomach into an open-mouthed vial.  In this short space
of time digestion had already commenced, thus negativ-
ing the common notion  that an hour elapses before it be-
gins.   The vial was now placed in a water-bath, al a tem-
perature of  100°, and continued there for five hours.  Ex-
amined at the end of that time, the whole contents were 
 104        MODE OF ACTION OF GASTRIC JUICE,

 found to be dissolved.   On then extracting an equal quan-
 tity of chyme  from the stomach, and comparing it with
 the solution in the vial, little difference was  observable
 between them,  except  that the  process had been some-
 what more rapid in than  out of the stomach.   But this expe-
 riment is remarkable in another point of  view, as showing
 that in the short space of twenty minutes enough  of gastric
 juice had been secreted for the entire completion of digestion.
   With a view to  verify these results, and  also to disco-
 ver the comparative digestibility  of different kinds of  ali-
 ment,  Dr.  Beaumont  gave St.  Martin  for dinner eight
 ounces of recently-salted lean beef, four ounces of potatoes,
 some bread, and four ounces of boiled  turnips.   After  fif-
 teen minutes he withdrew a  portion  of the contents of
 the stomach, and found  that some of the  meat had already
 been  slightly digested.   In a  second  portion,  withdrawn
 at the end of forty-five minutes, fragments of the beef and
 bread were perceptible,  and in  a still more  advanced state
 of digestion ;  the meat was in small shreds, soft and pul-
 py, and the fluid containing it had become more opaque
 and gruel-like   in  appearance.   When two hours  had
 elapsed a third quantity  was taken out,  at which time near-
 ly all the meat  had  become chymified  and  changed into a
 reddish brown  fluid ; but small pieces  of vegetable matter
 now presented themselves for the first  time, but  in a state
 of digestion so  much less  advanced than the meat, that
 their peculiar structure  was still distinctly visible.  Some
 of the second and third portions,  put into a vial and treat-
 ed in the  usual way, advanced to complete digestion, as
 in  the  other  experiment,  except that the process was
slower, and  that a  few vegetable fibres  remained to  the
last undissolved ; thus confirming the general opinion that
vegetables  are   more difficult  of digestion  than animal
substances.
  The mode of solution by the  gastric juice  varies ac-
cording to the nature of the food on which it acts.  We
have seen that it gradually reduces solids  to a soft  and
 fluid state ;  but  its  effect on milk and albumen is diffe-
 rent.   It begins by  coagulating them,  so as to give them
 the requisite consistence for being affected  by the  muscu-
 lar  contractions of  the  stomach,  and impregnated with
 the juice.   Fifteen  minutes  after St.  Martin had drunk
 half a pint  of milk, a portion  taken out of the stomach 
ACTION OF GASTRIC JUICE ON LIQUIDS.       105
   by Dr.  Beaumont  presented  the appearance  of  a fine
   loosely-coagulated substance, mixed with  a semi-transpa-
   rent whey-coloured fluid.   A drachm of warm gastric juice
   poured into two  drachms  of  milk, at a  temperature of
   100°, produced a precisely similar appearance  in twentv
   minutes.   In another experiment, when  four ounces of
   bread were given  along with a pint of milk, and the  con-
   tents  were  examined at the end of  thirty minutes,  the
   milk was coagulated, and the bread reduced to a soft pulp
   floating in a large  proportion of fluid.  In two hours  the
   whole was digested.
     When the white or albumen  of two eggs was swallowed
   on an empty stomach, small white flakes began to be  seen
   in about ten or fifteen minutes, and the mixture soon as-
   sumed an opaque  whitish appearance.  In an hour and  a
   half the whole had disappeared.   Two drachms of albumen,
   mixed with two of gastric juice out of the stomach, under-
   went  the same changes, but in a rather longer time.
     When the food is chiefly liquid, as when soup is taken
f   either alone or in large proportion, the more fluid part is
   speedily absorbed, to fit the remaining nutritious portion for
   being better acted  on by the gastric juice and  muscular
   power of the stomach ; but in impaired digestion the re-
   quisite absorption of the fluid part does not go on so rapidly.
   Fifty minutes after St. Martin had dined on vegetable soup,
   beef, and bread, Dr. Beaumont found the stomach to contain
   a pulpous mass, like thick gruel in consistence, and of  a
   semi-gelatinous aspect.   The fluid portion had been absorb-
   ed to  such an extent, that the remainder was even thicker
   than is usual after eating  more solid food.  From many
   similar observations, Dr. Beaumont infers it to be a general
   law, that soups and liquids cannot be digested till they are
   formed into a thicker mass by the absorption of their watery
   part—as till then  they are too liquid~to be easily acted on
   by the gastric  juice.  Hence their unfitness for weak sto-
   machs, and the impropriety  of large libations of tea or coffee
   at breakfast by persons whose digestion is bad.  During
   recovery from illness, chicken-tea, beef-tea, and soups are
   often useful, simply because the system then requires the
   liquid to  make up its lost blood.
      Unfortunately Dr. Beaumont made few experiments on
   the action of gastric juice upon  vegetables ; and, in the few
   recorded, he generally contents himself  with  noting the 
106   INFLUENCE OF TEMPERATURE ON DIGESTION.

length of  time required for their solution, which generally
proved considerably longer than for animal substances. , In
one experiment,  however,  he states, that an  hour after
giving St. Martin  nine ounces of raw, ripe,  sour apples,
the stomach was  full of fluid and pulp, "quite acrid, and
irritating the  edges of  the aperture, as is always the  case
when he cats acescent  fruits or vegetables."   In an hour
and a half the contents were  still more  sharp and acrid,
and the pulp of  the apple  visible.  At  the end  of  two
hours the"  stomach was empty, but the mucous membrane
exhibited  an  irritated  appearance.  With farinaceous ve-
getables, however, the results were different.   Thus, when
a pint of thick, rich, boiled sago, sweetened with sugar, was
given, the whole was digested in less than two hours, and
there was neither  acrimony of the  gastric  contents nor
smarting of the edges  of the Wound ; on the contrary, it
seemed peculiarly grateful to the stomach, and rendered
the mucous membrane soft, uniform, and healthy.   The
same results followed  a repetition of the  experiment, and
also when a pint of soft custard was taken.  In some states
of  the stomach, it  is true, even farinaceous food excites
acrimony  and irritation, but rarely in the same  degree as
the other  forms of vegetable aliment.
   Such being the  influence of gastric juice on different
aliments at the natural heat of the body, we have  now
to ascertain,  in  the second place, what share the high
temperature has in the  result.
   To determine  this point, Dr. Beaumont  took out  two
ounces of gastric juice, and divided it into two equal  por-
tions, in separate vials.   He added to each an equal weight
of masticated fresh beef;  and placed the  one in a bath at
the temperature of 99°, and the other in the open air at
34°.  As  a contrast to these, he placed beside the latter a
third vial,  containing the same weight of masticated meat
in,an ounce of clear water.
   In  two  hours the meat in the warm vial was  partially
digested;  that  in  the cold gastric juice was  scarcely
changed ;  and the third portion, in the cold water, seemed
only a little macerated.  In six  hours the meat in the warm
vial was half digested, while that in the  two others  had
undergone no farther alteration.  The gastric juice in the
first viaPhaving by this time dissolved as much as it could
of the beef, four drachms  more were  added from the  stc- 
       INFLUENCE OF TEMPERATURE ON DIGESTION.    107

mach, and the  vial was replaced in the bath.   Digestion,
which had previously ceased, was now resumed, and went
on as steadily as if it had not been interrupted ; thus show-
ing,  in a striking manner,  the  impropriety of exceeding
in our meals the  quantity for which  alone a sufficiency of
gastric juice can be provided.
  At the  end  of twenty-four hours  the  three portions
were examined.  That contained in the warm  juice was
completely dissolved, and presented the usual appearances.
The portions contained in the cold  juice and in the  cold
water very much resembled each other, and exhibited no
appearance whatever of chyme.   They were macerated or
softened, but not digested.  These experiments, and others
of a similar nature, show  clearly that a temperature equal
to ordinary blood-heat is requisite for chymification.
  To make sure that it was the low temperature alone
which prevented the occurrence  of digestion in the experi-
ment detailed, Dr. Beaumont now placed the vial containing
the meat which had been exposed without effect for twenty
hours to  the action of the cold  gastric  juice on a water-
bath at the  ordinary  blood-heat.   In a very  short  time
" digestion commenced, and advanced regularly as in the
other parcels."  The same results were always obtained
from a repetition  of these experiments, so  that  they  may
be held  as perfectly conclusive in establishing  the  essen-
tiality of heat to the digestive process.   Common obser-
vation, indeed,  establishes this truth.  Dr.  Kitchener, for
example, after  stating that  " a  certain degree of heat  is
absolutely necessary to excite and support a regular process
of digestion," remarks that, "when the  circulation is lan-
guid and  the  food difficult of  solution in aged persons
and  invalids, even external  heat will considerably assist
concoction, and the application of the calefacient concave
(stomach warmer) will enable the digestive organs to over-
come refractory materials, and convert them into laudable
chyle."*
   Thirdly.—The necessity of gentle and  continued agi-
tation for  the accomplishment of digestion  is so obvious
from the preceding exposition,  that  it requires no direct
experiments to establish it.   When  portions of meat were
suspended  in the stomach, by a string so short  as to pre-
vent them from being fully subjected to the motion already
   »  Art of Invigorating and Prolonging Life, 3d edition, p. 180. 
108    INFLUENCE OF THE MUSCULAR CONTRACTION

described as always going on during digestion, the  action
of the gastric juice was confined almost entirely to their
surface, and a longer  time was, consequently, required for
their solution than when they were left at liberty.  In like
manner, when meat  out of the stomach was placed  in a
vial containing gastric  juice,  its solution  was  uniformly
accelerated by gentle agitation, which acted  simply by
removing the coating of chyme as it formed on the surface,
and thus affording to  the gastric fluid an easier access to
the undigested portions below.  Accordingly, when  in one
of Dr. Beaumont's experiments two ounces of unmasticated
roasted beef were introduced through the external aperture
into the stomach, and held by a string, only one-half of it
was digested  in four hours, evidently from  the want of
mastication  confining the  action of the gastric juice  to
the surface of the mass, and because the string prevented
it from following the regular motions of the stomach.
   Having now made the reader sufficiently  acquainted
with the agents concerned in,  and the conditions essential
to, the performance of digestion out of  the body, we have
next to exhibit the same  agents and  the  same conditions
in their ordinary operation in the living being, and to describe
the beautiful arrangements by which they are respectively
and unerringly regulated.
   It has been already  shown  that, in  endowing us with
appetite, Nature has intended both to ensure by its means a
timely provision for the  wants  of the system, and to guard
against our eating more  than enough to  supply them.  We
have also seen that, within certain limits,  the quantity of
gastric juice secreted bears a direct relation to the quantity
of food consumed ; that when the food exceeds considerably
the real  necessities of  the system, a part of it remains
undigested,  because the stomach  is  unable to secrete a
sufficiency of  fluid for the  solution of  the whole, and that,
as a  necessary consequence,  indigestion  follows.   This
being the  case, we may expect to find  all the arrangements
of Nature made  with  a view to prevent us from  hastily
filling the stomach to  repletion, without  being fully warned
beforehand of the  error we are committing.   And such,
accordingly, is the fact.
   Considered in  this light, the processes  of mastication,
insalivation, and deglutition are not only useful in prepa-
ring the morsel for the future action of the gastric juice, 
OF THE STOMACH ON DIGESTION.         109
but, by transmitting  the food to the  stomach  in  small
portions at a time, likewise serve the important secondary
purpose of preventing its too  rapid or excessive distention.
To this good end, indeed, the stomach itself contributes,
as has been distinctly shown by Dr. Beaumont.  In the
natural state of that organ a regular and gentle contraction
of its whole fibres and cavity follows the introduction of
each  individual morsel,  and  it is not till the relaxation
consequent on that contraction takes place, that another is
willingly admitted.    This arrangement was more  than
suspected  by other  physiologists, but it remained for the
American experimenter  to demonstrate its  existence and
purposes.   It  is  true that,  during a hurried repast, for
example, food may be rapidly introduced into the  stomach
by an active effort of the will, but it is precisely in such
circumstances that we are apt to eat too much,  and that
indigestion follows ; because,  from no time  being allowed
for the secretion  of the requisite quantity of gastric juice,
and its proper  mixture with  each portion of the  aliment,
the stomach is placed in an  unnatural situation, and its
nerves cannot  receive the same  impression of " enough
eaten,"  which is  designed by Nature to  arise only from
the one being  duly proportioned to, and  mixed with, the
other.  The advantage of the natural arrangement is, there-
fore, confirmed rather than refuted  by what may at first
appear an exception.
   When Dr. Beaumont depressed the valve in St. Martin's
stomach, and  introduced a few spoonfuls of soup at the
orifice, he observed the ruga? or folds of the mucous mem-
brane to close gently upon it, gradually diffusing it through
the gastric cavity, and completely preventing the  entrance
of a second quantity till  this diffusion was effected—when
relaxation again took place, and admitted of a farther supply.
When solid food was introduced in the same way, either in
larger pieces or finely divided, the same gentle contraction
and grasping motion were excited, and continued from fifty
to eighty seconds, so as  to prevent more from being intro-
duced without  considerable force till the  contraction was
at an end.  When St. Martin was so placed as to admit
of the cardia or upper orifice of the stomach  being brought
into view,  and was then  made to swallow a morsel of food
in the natural  way, a similar contraction  of the stomach,
and closing of its fibres upon the bolus, was Invariably 
 110      ADMIXTURE OF FOOD AND GASTRIC JUICE.

 observed to take place; and, till this was over, a second
 morsel could not be received without a considerable effort.
 And accordingly, when,  either from haste or hunger, we
 disregard the order of Nature, and hurriedly gulp down food
 without due mastication, and without allowing time  for the
 regular contraction  of the stomach,  we necessarily ex-
 pose ourselves to the  risk, both of overloading  it and of
 ultimately impairing its digestive power.
   Such being the provision made for ensuring the gradual
 admission of food into the stomach, the next requisite is
 its proper admixture with the gastric juice.
   Food being the appropriate stimulus of the secreting ves-
 sels of the stomach, the moment  the alimentary morsel
 comes into contact with the mucous  membrane, the ac-
 tion of the latter, as was formerly pointed out, becomes in-
 creased ;  its bloodvessels are distended, its colour deepens
 to a brighter red, and the gastric juice immediately begins to
De poured out.   The muscular fibres of the stomach, being
 acted upon by the same stimulus, next  come into play, and
 execute their specific function of alternate contraction and
 relaxation.   By these means the aliment speedily becomes
 impregnated with the gastric fluid, and  undergoes the influ-
 ence of that continued gentle  agitation already described
 as essential  to digestion, and which seems to have  for its
 chief object the careful admixture of every portion of the
 nutriment with the quantity of  gastric  juice necessary for
 its solution.   The particles  of food are  thus continually
 changing  place, and if the quantity taken be not to great
 for the power of the gastric juice which  the stomach can
 supply, chymification goes on equally throughout; so that,
 if the contents of the stomach be withdrawn in from thirty
 minutes  to an hour after  a moderate meal, they will be
 found to consist of perfectly formed chyme and  particles
 of food, intimately  mixed and blended,  in larger or smaller
 proportions, according to the vigorous or enfeebled  state
 of the digestive organs, and the quality of the aliment it-
 self.   So effectually, indeed, has the admixture of food and
 solvent juice taken place in this short time, that, as already
 shown, when a portion is removed  from the stomach and
 placed in an appropriate vessel, digestion will commonly
 continue in it, provided it be placed in a proper temperature
 and subjected to gentle and continued  agitation.
   It is the impossibility of its being adequately acted upon 
         ADMIXTURE OF FOOD AND GASTRIC JUICE.     Ill

by the muscular contractions of the stomach which renders
fluid and highly concentrated nourishment, when exclusively
used, so difficult of digestion ; and hence the reason why a
certain bulk and consistence given to whale oil, for example,
by the admixture of such innutritious substances as vege-
table fibre, bran, or even saw-dust, make it a more accep-
table and digestible article of food to the inhabitants of the
northern regions, than when it is consumed in its pure state.
In like manner, in civilized society, bread, potatoes, and
vegetables are useful, not less by giving the requisite bulk
and consistence to the rest of the food, than by the nutri-
ment which they contain.  Soups, jellies, arrow-root, and
similar substances are, for the same reason, more easily di-
gested when eaten along with bread or some bulkier aliment,
than when taken alone, especially if used for some  time.
  The motion  which we have seen to be excited in the
stomach by the entrance of aliment  is at first  very gentle
and  slight; but in proportion as digestion proceeds or the
organ is distended, it becomes more rapid and energetic;
and  then it serves the additional  purpose of gradually pro-
pelling  the chyme through the pylorus into the intestine,
there to be farther prepared and converted into chyle.   The
necessary churning or agitation of the food is, from the pecu-
liar  situation of the stomach, greatly assisted by the  play
of the diaphragm and abdominal muscles during inspiration
and  expiration ; and the diminution of the vivacity and ex-
tent  of the respiratory movement which always attends des-
pondency and grief, is one source of the enfeebled digestion
which notoriously accompanies or follows  depression of
mind.   The same cause also leads necessarily  to an unfa-
vourable condition of the blood  itself, which  in its turn
weakens digestion in common  with every other function ;
but the muscular or mechanical influence is that which  at
present chiefly concerns us.   On the other hand, the active
and  energetic respiration attendant  on cheerfulness  and
buoyance  of spirits, adds  to the  power of digestion, both
by aiding the motions of the stomach  and by imparting  to it
a more richly constituted blood.   If to these causes be add-
ed the increase of nervous stimulus which pleasing emotions
occasion in the stomach, (as in  the muscles, and organs of
secretion generally,) we shall have no difficulty  in perceiv-
ing why digestion goes on so well in  parties where there is
much jocularity and mirth.   " Laughter," says Professor 
112      GASTRIC JUICE ACTS ON EVERY PORTION
 Hufeiand, of Berlin, " is one of the greatest helps to diges-
 tion with which I am acquainted ;  and the custom prevalent
 among our forefathers, of exciting it at table by jesters and
 buffoons, was founded  on true medical principles.  In a
 word, endeavour to have cheerful and merry companions at
 your  meals : what  nourishment  one receives amid mirth
 and jollity will certainly produce good and light blood."*
   Exposed to the  action of all the  agents above enume-
 rated, and to the increased nervous and vascular excitement
 which are necessary during digestion, a  singular change
 soon commences in the  food, and goes on till chymification
 is completed.  After a little while  the  contents of the
 stomach, whatever their nature and variety, begin to be
 converted into a substance of a homogeneous, soft, grayish,
 and viscid appearance, of a sweetish, fade, and slightly acid
 taste, but which still preserves some  of the qualities of the
 food,  and is called  chyme.  The chyme  always forms on
 that part of the food with which the  gastric juice  is in im-
 mediate  contact; and, in proportion  as it is produced, it is
 carried gradually onward by the gentle motion of the sto-
 mach  toward the pylorus, where, consequently, it always
 exists in the greatest quantity.   At the cardiac or left end
 of the stomach it is most sparingly found, both  because
 digestion is there only beginning, and because the chyme is
 speedily  removed from it and carried away toward the py-
 lorus.
  The doctrine hitherto generally received,  and  held  by
Dr. Wilson Philip and others as demonstrated, is, that " the
layer of food lying next to the surface of the stomach  is
first digested, and in proportion as this undergoes  the pro-
per change, and is moved  by the  muscular action of the
stomach, that next in turn  succeeds, to undergo the same
change."   Dr. Beaumont,  however,  declares that, what-
ever may be the case in  rabbits and other animals on which
Dr. Philip's experiments were  made, such was  not  the
order  observed in the stomach of Alexis St. Martin—and
such, he naturally infers, is not the order in the human sto-
mach in general.  Nor is such, I may add, the order which
either experience or a correct view of the antecedent cir-
cumstances  and physiological conditions ought to lead  us
to anticipate.   When vomiting, for instance, occurs an hour
  » Art of Prolonging Human Life, English edition.  London, 182a
P. 282 
              OF FOOD WHICH IT TOUCHES.           113

or two after a meal composed of, different ingredients has
been swallowed, no such separation into digested and un-
digested portions is to be found, but the whole are observed
to have undergone changes proportioned to their degrees
of digestibility, whether they were eaten first or last.
   In conformity with this view, Dr. Beaumont  mentions,
that, when, St. Martin swallowed a mouthful of any tena-
cious food after the digestion of the preceding meal was con-
siderably advanced, he always saw it first pass toward the
great curvature of the stomach, and then disappear.  In a
minute or two it reappeared, more or less broken  down,
and mixed with the general alimentary mass ; and in a short
time longer it was so much  changed as entirely,to lose its
identity.  From these and numerous other facts, Dr. Beau-
mont infers, that " there is a perfect admixture of the whole
ingestae during the  period of alimentation and chymifica-
tion ;" and that " the whole contents of the stomach, until
chymification be nearly complete, exhibit a heterogeneous
mass of solids and fluids—hard  and soft, coarse and fine,
crude andchymified—all intimately mixed, and  circulating
promiscuously through the  gastric cavity, like the mixed
contents of a close vessel, gently agitated or  turned in the
hand."  (P.  112.)  As we proceed  we shall  meet with
various indirect proofs of these statements being correct.
   If Dr. Beaumont's observations on this subject are accu-
rate, we may expect to find  that chymification commences
on the surface of each individual fragment of the food, and
is not confined to the outer surface of the entire alimentary
mass, as stated  by Dr. Philip.   Such, accordingly, is the
fact.   When Dr. Beaumont extracted a portion  of the food
through the  opening half an hour or  an hour after eating,
he invariably found it composed of perfectly formed chyme
and particles of food intimately mixed and blended ; and
in these  experiments every portion  of the  aliment was
already so completely supplied with gastric juice, that its
chymification proceeded till the whole was digested with
no other aid  than  that of the requisite heat and agitation.
   When  a meal is taken  before the preceding one is out
of the stomach, digestion is  observed to be disturbed.  Dr.
Wilson Philip explains this by stating, that the newly swal-
lowed food becomes imbedded in, and occupies the centre
 of, the  older  and half-digested mass, where it remains dis-
 tinct and  untouched till the former meal is entirely disposed
                         10* 
114     GASTRIC JUICE ACTS ON EVERY PORTION
 of.  A more logical explanation, however, and one more in
 harmony with  facts,  is  offered by  Dr.  Beaumont,  who
 ascribes  the disturbed digestion  to  the supply of gastric
 juice having been entirely taken up by the first meal, and to
 the stomach, now comparatively exhausted, being unable to
 secrete a fresh  supply for the second—seeing that, in ordi-
 nary circumstances, its vessels secrete only enough  to meet
 the real  wants  of the system.  Dr. Beaumont adduces, in
 confirmation of this view, the fact that  many children, and
 most cooks, are in the habit of eating small quantities of
 food almost evoryhour or two without  their digestion suf-
 fering materially, because then the amount of gastric juice
 secreted is quite equal to  the chymification of the whole
 quantity  taken.
   Reasonable as this inference appears from the facts stated
 by Dr. Beaumont, I cannot help thinking that there is some-
 thing more in the constitution of the stomach than the mere
 deficiency  of gastric juice,  which renders the too early in-
 trusion of new  food hurtful.  We know, for example, that,
 at the commencement of digestion, the muscular contrac-
 tions of the stomach are comparatively slow and feeble, and
 that as chymification advances they become rapid  and ener-
 getic, as  if to remove the chyme as fast as it is formed.  If,
 then, new  food, for which the feebler  movement  is  best
 adapted,  be introduced when digestion is far advanced and
 the energetic motion going on, may not this disproportion
 be itself an impediment, and co-operate with the deficiency
 of the gastric juice in disordering digestion'?  Moreover,
as the  stomach, in common with every other organ  intend-
 ed for alternate  activity and repose, is always more or lesa
fatigued by the  active fulfilment of its function, its  prema-
 ture excitement by new food must add to  its exhaustion
and weaken its power, (in  the same way in  which  fresh
muscular exertion adds to the exhaustion of muscles already
sufficiently exercised,) and, consequently, lead to imperfect
digestion.
   Th% same principle which explains the necessity of re-
pose for  repairing the vascular and nervous energy of the
 stomach, when  these have been excited and exhausted by
 the labour of digestion, also affords a solution of the ques-
 tion why the appetite does not return as  soon as the  sto-
 mach is empty,  but  begins to be felt only after the latter
 has enjoyed a period of repose, varying in duration with tha 
              OF FOOD WHICH IT TOUCHES.           115

mode of life, the state of health, and the nature of the pre-
vious meal.
  If we regard chymification as going on at the surface of
every individual portion of the food, we at once see that
the constant  motion  of the stomach serves, not only to
affect the original mixture of the food with the gastric juice,
but to remove  the chyme from the surface of  each little
fragment of the alimentary mass  in  proportion  as it is
formed, and by this very removal to expose a fresh surface
of the fragment to the contact of the mucous membrane,
thereby enabling it to excite a farther secretion of the gas-
tric juice, where, as  sometimes happens, the  stomach is
unable to provide a sufficient quantity from the beginning.
In this way the formation and removal of chyme go on from
the very first,  although, of  course, more slowly than after
the gastric solvent has had time to act.   It is generally said
that an hour elapses before any chyme is formed ; but Dr.
Beaumont  has detected its existence at a much  earlier
period, and is of opinion that, from the uniform and constant
decrease in the contents of the  stomach, which begins as
soon  as the food is  swallowed, chymification commences
almost  immediately.   This decrease, though slow at first,
becomes gradually accelerated, till the whole mass is con-
verted into chyme.   Apparently in harmony with this more
energetic action, the acidity of the gastric fluid  also be-
comes greater, and affords a greater stimulus, in proportion
as digestion advances.
   As  formerly explained, the thickish, semi-fluid, grayish
chyme  into which  the aliment  is converted, is gradually
impelled toward the pyloric extremity of the stomach.  On
its arrival there the pylorus, or valve between the stomach
and the intestine called the duodenum, opens  and  allows
the chyme to pass into the intestine.   But, by a curious
mode  of sensibility, if any portion of  undigested food be
mixed  with it, the pylorus contracts  upon it, refuses it
egress, and throws  it back into the stomach  for farther
digestion.
   If, however, anything really indigestible finds its way into
the stomach, and presents itself at the pylorus—or if the
stomach has temporarily lost  its digestive power, and the
food remains  in  it for  many hours unchanged—then the
pylorus, after  repeatedly refusing egress, at last opens and
allows it to pass into the gut.  So marked is the contractile 
116         COMPARATIVE DIGESTIBILITY OF
impulse toward the pylorus when  digestion is  going on,
that Dr. Beaumont found even the bulb of his thermometer
carried down with a steady and considerable force.
  Such are the direct conditions requisite/or the fulfilment
of digestion : but there remain others, of an indirect kind,
which also require to be noticed.   Of these, a due supply
of arterial blood and nervous energy is the most  remarka-
ble; but as both  produce  their effect by modifying  the
secretions and motions of  the stomach,  already described
as the direct requisites of digestion, it will save a good deal
of repetition if, for the present, we  take their influence for
granted, and reserve their farther elucidation till we come
to treat of the practical applications of the preceding expo-
sition.
  Having thus obtained  a  comprehensive view of the
agents employed in effecting digestion, and of the changes
produced by it on different kinds of food, we find another
important subject of investigation,  immediately connected
with the process,  presenting itself—the comparative diges-
tibility of different kinds of food.  Dr. Beaumont did not
neglect this branch of the inquiry ; but the experiments
which  he performed for its  elucidation  are, like those of
most of his predecessors, deprived of great part of their
value by the vague  way in  which they seem to have been
conducted, and the common omission of all particulars in
regard to those  conditions which  are  known to exert  a
powerful influence on the progress  of digestion.
  The following table, which I have arranged in a more
lucid order than Dr. Beaumont has done, exhibits the ge-
neral results of all the experiments made upon St. Martin
posterior to  1825 ; and the average is deduced from thosa
which were  performed when  the stomach was  considered
by Dr. Beaumont to be in its natural state,  and St. Martin
himself subjected  to ordinary exercise. 
DIFFERENT KINDS OF FOOD.
117
TABLE  showing the Mean  Time of Digestion of the
              different Articles of Diet.
	Mode	Time re-
Articles of Diet.	of	quired for
	Preparation.	Digestion.
Rice - ...	Boiled	H. M. 1
Pig's feet, soused	Boiled	1
Tripe, soused ...	Boiled	1
Eggs, whipped ...	Raw	1 30
Trout, Salmon, fresh	Boiled	1 30
Trout, Salmon, fresh -	Fried	1 30
Soup, barley ...	Boiled	1 30
Apples, sweet and mellow	Raw	1 30
Venison steak	Broiled	1 35
Brains ....	Boiled	1 45
Sago.....	Boiled	1 45
Tapioca -	Boiled	2
Barley - •	Boiled	2
Milk ....	Boiled	2
Liver, beef's, fresh -	Broiled	2
Eggs, fresh ...	Raw	2
Codfish, cured, dry ...	Boiled	2
Apples, sour and mellow	Raw	2
Cabbage, with vinegar	Raw	2
Milk ....	Raw	2 15
Eggs, fresh -	Roasted	2 15
Turkey, wild -	Roasted	2 18
Turkey, domestic -	Boiled	2 25
Gelatine - -	Boiled	2 30
Turkey, domestic -	Roasted	2 30
Goose - - -	Roasted	2 30
Pig, sucking •	Roasted	2 30
Lamb, fresh ...	Broiled	2 30
Hash, meat and vegetables	Warmed	2 30
Beans, pod -	Boiled	2 30
Cake, sponge	Baked	2 30
Parsnips	Boiled	2 30
Potatoes, Irish	Roasted	2 30
Potatoes, Irish -	Baked	2 30
Cabbage, head	Raw	2 30
Spinal marrow -	Boiled	2 40
Chicken, full grown	Fricassee	2 45
Custard -	Baked	2 45
Beef, with salt only	Boiled	2 45
Apples, sour and hard •	Raw	2 50
Oysters, fresh ...	Raw	2 55
Eggs, fresh	Soft boiled	3
Bass, striped, fresh . - -	Broiled	3
Beef, fresh, lean, rare -	Roasted	3
Beef steak -	Broiled	3
Pork, recently salted -	Raw	3
| Pork, recently "salted	Stewed	3
 
118          COMPARATIVE DIGESTIBILITY OF
TABLE showing Mean Time of Digestion—continued.
	Mode	Time re-	
Articles of Diet.	of	quired for	
	Preparation.	Digestion.	
Mutton, fresh ...	Broiled	H. 3	M.
Mutton, fresh ...	Boiled	3	
Soup, beans ...	Boiled	3	
Chicken soup ...	Boiled	3	
Aponeurosis ...	Boiled	3	
Cake, corn ....	Baked	3	
Dumpling, apple Oysters, fresh ...	Boiled	3	
	Roasted	3	15
Pork steak ...	Broiled	3	15
Pork, recently salted	Broiled	3	15
Mutton, fresh	Roasted	3	15
Bread, corn	Baked	3	15
Carrot, orange -	Boiled	3	15
Sausage, fresh	Broiled	3	20
Flounder, fresh	Fried	3	30
Catfish, fresh ...	Fried	3	30
Oysters, fresh - •	Stewed	3	30
Beef, fresh, dry ...	Roasted	3	30
Beef, with mustard, &c.	Boiled	3	30
Butter ....	Melted	3	30
Cheese, old, strong	Raw	3	30
Soup, mutton ...	Boiled	3	30
Oyster soup ...	Boiled	3	30
Bread, wheaten, fresh	Baked	3	30
Turnips, flat ...	Boiled	3	30
Potatoes, Irish ...	Boiled	3	30
Eggs, fresh ...	Hard boiled	3	30
Eggs, fresh ....	Fried	3	30
Green corn and beans • •	Boiled	3	45
Beet -	Boiled	3	45
Salmon, salted -	Boiled	4	
Beef, fresh, lean	Fried	4	
Veal, fresh ...	Broiled	4	
Fowls, domestic ...	Boiled	4	
Fowls, domestic	Roasted	4	
Ducks, domestic ...	Roasted	4	
Soup, beef, vegetables, and bread	Boiled	4	
Heart, animal ...	Fried	4	
Beef, old, hard, salted -	Boiled	4	15
Pork, recently salted - .	Fried	4	15
Soup, marrow bones -	Boiled	4	15
Cartilage - " - . .	Boiled	4	15
Pork, recently salted -	Boiled	4	30
Veal, fresh ....	Fried	4	30
Ducks, wild ...	Roasted	4	30
Suet, mutton	Boiled	4	30
Cabbage, with vinegar -	Boiled	4	30
Suet, beef, fresh ...	Boiled	5	3
Pork, fat and lean	Roasted	5	15
Tendon ....	Boiled	5	30
 
               DIFFERENT KINDS OF FOOD.    s        119

  This table is very interesting, but the results must nAt
be too much relied upon, or regarded as  representing the
uniform rate of digestibility.   We have already seen that
chymification  is greatly influenced by the  interval which
has elapsed since  the  preceding  meal, the  amount of ex-
ercise  taken, the keenness of the appetite, the state of the
health  and mind, the completeness of  the mastication, the
state of rest or exercise after eating, and various other cir-
cumstances ; and, above all, the quantity swallowed, in pro-
portion to the gastric juice secreted.  And, consequently, if
an experiment be made without regard to these conditions,
and  without anything  being recorded,  except the time oc-
cupied in digestion in the individual  case, the conclusions
deduced from it may be most fallacious.  The very aliment
which, taken in full quantity, remains on the stomach for
hours,  may, in a smaller quantity,  be entirely digested  in
one-third of the time.  Thus, in the  foregoing  table, two
and a  half hours are   set down as  the average period re-
quired for the chymification of jelly ; and yet, in one of Dr.
Beaumont's experiments, we find that eight ounces of that
substance were entirely digested  in  one  hour.   So that,
if all the  other conditions are not carefully kept in view at
each trial, the results cannot  possibly be held  as  conclu-
sive.
   It may be said  that, on the  occasion just alluded to, St.
Martin's digestion must have been particularly good—and,
in truth, it seems to  have  been  so; for at nine  o'clock,
a. m., he breakfasted  on  soused tripe,  pig's feet, bread and
coffee, and yet one hour  later no vestige of any  of  these
savoury things remained in  the stomach.  What  renders
 this result the more  remarkable, is the  fact, that, in an-
other  table, a simple breakfast of coffee  and  bread is set
down  as  having  required  four hours for its digestion.
The rapid disposal of the same elements with the addition
of soused tripe and  pig's  feet, instead of disproving my
position,  evidently strengthens it, by showing that, if from
any cause the digesting power varies in  intensity, the re-
 sult obtained  from the  experiment  on one kind  of food
 cannot, with any  show of reason, be  considered as an ac-
 curate index of its rate of digestibility in comparison with
 that of other kinds.
   This neglect of the other conditions is accordingly the
 circumstance which throws a doubt  over the results, not 
120         COMPARATIVE DIGESTIBILITY OF
only of Dr. Beaumont's experiments, but of those of every
other inquirer.  Dr. Beaumont, indeed, candidly  admits,
that his were performed for the purpose of demonstrating
other important  principles  connected with digestion, and
not at all with the view of determining the comparative
rates of digestibility of different kinds of aliment; and, in
alluding to the various requisites for a satisfactory series
of experiments,  he himself justly  states, that this would
be a Herculean task which it would  take years to accom-
plish.  In considering the following general results, then,
the reader ought to bear in mind  that they are only pro-
bable and approximative, and not strictly demonstrated or
certain.
  As a general rule, animal food is more easily and speedi-
ly digested, contains a greater quantity of nutriment in a
given bulk, and, therefore, satisfies hunger  for  a longer
time  than  either  herbaceous  or farinaceous food;  but,
apparently from the same  cause,  it  is also more heating
and  stimulating.  Minuteness of division  and tenderness
of fibre are shown by Dr.  Beaumont's experiments to be
two grand  essentials  for the easy  digestion of butcher-
meat ; and the different kinds of fish, flesh, fowl, and game
are found  to vary in  digestibility  chiefly in proportion as
they approach or depart from these two standard qualities.
   Farinaceous  food,  such as  rice, sago, arrow-root  or
gruel, is  also  rapidly  assimilated,  and proves less stimu-
lating to  the system than  concentrated animal food ;  but
as it affords no scope  for the due  action of the muscular
coat of the  stomach, its  exclusive use for  any length  of
time seldom fails to weaken that organ and  impair diges-
tion.   For the same reason, however, it becomes a very
appropriate  aliment, where stomachic irritation  already
exists.  When  the stomach is  in  a healthy  state,  milk is
digested almost as  easily as farinaceous food, and is equally
unstimulating.
  The other kinds of vegetable  substance are the slowest
of all in  undergoing digestion,  and  very  frequently  pass
out of the stomach and through the bowels comparatively
little  changed ;  and  hence  the uneasiness which their
presence so often excites in the  intestinal canal, especially
in persons of weak digestion, owing to the nerves of the
intestines having a relation to chyme or digested food, and
not  to substances  which resist  the  action of the  gastric 
       DIGESTIBILITY OF DIFFERENT KINDS OF FOOD.   121

juice.   In a given bulk they contain less nutriment, and
excite the system less, than any other kind of food ; so
that they are well adapted for the diet of those in whom
it is necessary  to avoid every kind of stimulus, and who
are not subjected to great muscular exertion ; but to a per-
son undergoing hard labour they afford inadequate support.
  Liquids—soup, for example—do not call into play the
muscular coat of the stomach, and are so slow of digestion
where that organ is already weakened, that they often give
rise to acidity ; and hence they are unfit for most dyspep-
tic  patients.  Before the gastric juice can act upon them,
the fluid part must be  absorbed and the mass thickened
to a proper consistence for undergoing the usual churning
motion.   On examining the contents  of the stomach an
hour after St. Martin had dined on beef soup, Dr. Beau-
mont found  that  on one  occasion  the absorption of the
watery part had been carried so far as to leave the remain-
der of even  a  thicker consistence than after an ordinary
solid meal, but a similar result follows only when the diges-
tive powers are very vigorous.   When drink'is swallowed,
it also is carried  off by absorption, and is not digested or
allowed to pass through the pylorus.  One purpose of this
provision seems  to be  to prevent the gastric juice from
being rendered inefficient by too much dilution.
  When the food on which an animal lives  is of a highly
concentrated kind, and  contains much nourishment in  a
small bulk,  the apparatus of organs provided for its diges-
tion is on a correspondingly small scale in point of extent.
Thus, in carnivorous  animals, whose food is, bulk for bulk,
the most nutritions of all, the stomach and  intestines are
simple and short, the latter not exceeding in length  more
than from one to four or five times that  of the body.  In
herbivorous animals, on  the  other  hand, whose  food  is
sparingly nutritious, and, therefore, requires to have a large
bulk or  volume, the stomach, as we saw in a former chap-
ter, is greatly more  complicated, and the  length of the
intestines enormously increased.  Man,  being intended to
feed on both animal  and vegetable substances, possesses
an  organization which holds an intermediate  place between
the two extremes.   In him neither are  the intestines so
short as in  carnivorous  animals, nor  have  they the com-
plexity  and length characteristic of the herbivorous—thus
rlearly  showing the intentions of Nature in regard to his
                           II 
 122      WHY ANIMAL FOOD IS MORE DIGESTIBLE

 food, and at the same  time allowing  him  a considerable
 latitude of adaptation  when  the force  of  circumstances
 for a time denies turn access to any variety.
   Animal food being in general more  quickly digested
 than vegetable, and a simpler organization being sufficient
 for  its conversion  into  chyme, many physiologists  have
 inferred that  this is owing solely to its being  already of
 an animal nature,  and, therefore, requiring  scarcely  any
 change to fit  it for becoming a constituent part  of the
 living fibre.  But I agree with Dr. Beaumont  in thinking
 that this explanation is more gratuitous than philosophical,
 and that the process of chymification implies  almost as
 complete a change in the  one instance  as  in  the other.
 In both the operation of the gastric juice seems  to be en-
 tirely analogous.  In both a complete solution takes place,
 and the chyle'into which animal food is ultimately convert-
 ed, bears no greater resemblance to the future animal fibre
 than  does that produced from vegetable aliment.   Thus
 the chyle of a  horse, which lives exclusively on vegetables,
 has  quite as great  a resemblance to its  future muscle, as
 that of a tiger, a lion, or a fox has to  its future produce.
 Besides,  whether the food be animal or vegetable, the ul-
 timate result of digestion is always  the  formation of new
 animal matter; but in the  former case the  nutritive par-
 ticles  are mixed up with a  smaller proportion  of innutri-
 tious matter than in the latter, and, consequently, a larger
 quantity of them can be  extracted from a given bulk in  a
 shorter time, than in the case of vegetables.   There are,
 most  probably,  also minute differences  in  the chemical
 composition of the  chyle derived from  different kinds of
 food ;  but its general nature—its fitness for  forming  new
 animal tissue—and that of  the process by which it is pro-
 duced, are always the same.
   Animal food, it is true, affords a more stimulating nutri-
ment than farinaceous and other kinds of vegetable aliment,
and hence it is  avoided in diseases of excitement.   But it
 seems to me that this stimulus is owing, not only to its own
inherent properties,,but also to its more highly concentrated
state, and to the much greater quantity of chyle which is
derived from it  than from an equal  bulk of  vegetable ali-
ment.  From the numerous experiments of injecting water,
poisons, and other substances into the veins,  performed by
Magendie and others, we have direct  proofs that the sain* 
THAN VEGETABLE.                123
 agent which, introduced rapidly into the system, will some-
 times act so powerfully as to destroy life, will excite scarce-
 ly any perceptible disorder if introduced very slowly.   Ana-
 logy, therefore, bears us  out in believing that  the rapid.
 admixture of very nutritious chyle with the blood may over-
 stimulate the system, when its more gradual introduction
 would have produced no such effect.   At  the same time,
 there can be no doubt that there is also a greater inherent
 stimulus in animal than in  vegetable aliment.
   It seems to be partly for the purpose of obviating the evil
 of the too  rapid introduction of nutriment, and  partly for
 that of varying  the stimulus, that Nature  has rendered a
 certain bulk of food advantageous to digestion, and decreed
 that no animal can long retain its  health if fed on  highly
 concentrated aliment alone.  Dogs fed on oil  or  sugar,
 which are almost wholly converted into chyle, become dis-
 eased and die in a few weeks ; and, as Dr. Paris has acutely
 remarked, the very capacity of our digestive organs is a proof
 that Nature never intended them  for the exclusive recep-
 tion of highly concentrated food.   Dr. Paris refers to post-
 horses fed chiefly on beans and corn, as instances among the
 lower animals of the insalubrity of too condensed nutriment,
 and shows that they live constantly on the brink of active dis-
 ease, and every now and then require bleeding, laxatives, and
 emollients, to keep them in condition.   Sportsmen, boxers,
 and others, who train themselves for severe exertion, are ad-
 ditional examples showing that a similar mode of living in-
 duces a morbid tension of the system which cannot be long
 kept up without danger.   The Kamtschatdales sometimes
 live with impunity for months on fish-oil, by wisely mixing it
 up with saw-dust or other indigestible vegetable fibre, which
has the double advantage of diluting the food and of afford-
ing due scope for the action of the muscular coat, and thus
placing the food in more perfect harmony with the constitu-
tion of he stomach.
  If the preceding explanation of the more  rapid digestion
 of animal than of vegetable substances, and the higher sti-
 mulus which they afford, be correct, the common notion of
 the former being more digestible than the latter, solely be-
 cause there is a greater.analogy between animal food and
 the system which it goes to nourish, and, therefore, a smaller
 change to be undergone,  necessarily  falls  to the ground.
 If it be true—which  it seems to be—that,  in the natural 
124        DIGESTIBILITY OF FOOD EXPLAINED.
state, in a temperate climate, animal food is more easily
digested than vegetable, the fair inference ought rather to
be that the system requires  the former in larger proportion
than the latter, and that the gastric juice is purposely con-
stituted with reference to this circumstance.  Accordingly,
in the  Arctic Regions, where the climate renders great  sti-
mulus  necessary, animal food, of to us the most indigesti-
ble kind—that consisting  of pure fat and oil—is eaten in
immense  quantities  and  digested  with  enviable facility ;
while in India and other tropical climates, where much less
stimulus is required, the natives digest  vegetable aliment
with at least equal ease and satisfaction.
  If, as Dr. Paris imagines, animal food owes its digestibi-
lity simply to its possessing " a composition  analogous to
that of the structure which it is designed to supply," and,
therefore, requiring  " little  more than division and depura-
tion,"  instead of the alleged " complicated series of decom-
positions and recompositions which must be effected before
vegetable matter can be animalized of assimilated to the
body,"*—it follows that butcher-meat must in all climates
and situations be more digestible than vegetables; and that
raw meat, which has the greatest analogy of all to the struc-
ture of the body, must require still  less digestive power for
its  solution and assimilation  than  cooked meat.   These
propositions, however, are wholly at variance with experi-
ence :  in particular,  the effect of cooking is unquestionably
to induce a change of composition subversive of the analogy
on which Dr. Paris rests his opinion.
  That the easier digestibility of animal food in man arises
chiefly  from its  greater adaptation to the  qualities  of  the
gastric juice, and not from any such  analogy as that now
alluded to, is rendered still more probable by the fact, that
in him the gastric fluid contains  scarcely any free acid, ex-
cept where the diet has consisted for some  time principally
of vegetables; whereas it always contains a  considerable
proportion of acid in herbivorous creatures.  In the latter,
moreover, the analogy is quite as great between animal sub-
stances and their own structure as in man, and yet to a cow
beef is  much more indigestible than grass, notwithstanding
the " decompositions and recompositions " which the latter
is supposed to require before becoming animalized.  Dr.
Beaumont is, therefore, quite justified in maintaining, that
                  ♦ Paris on Diet, p. 93. 
HEAT OF STOMACH DURING DIGESTION.      1251
the process of digestion implies as complete a solution and
recomposition in the case of animal as of vegetable sub-
stances ; and that the rapidity with which the chyrhification
of either is effected  depends  more on' its adaptation to the
properties of the gastric juice provided  by Nature for  its
solution, than on the closeness of resemblance oj its own
composition to that of the body of which it is to become a part.
  Another prevalent notion—that the digestive apparatus
is simpler and shorter in  carnivorous  than in herbivorous
animals, merely because their  food  is  more analogous in
composition to their  own bodies, and therefore requires less
perfect digestion—seems to me equally unfounded, and to
be negatived by the  fact that, in the grain-eating birds, in
the constituent  elements  of  whose food there is no such
analogy, the  intestines, nevertheless, scarcely exceed  in
length those of carnivorous  birds—a circumstance at va-
riance with the notion of  length being necessary solely  on
account of the great  elaboration required for the conversion
of vegetable  into animal substance.  The true principle—■
and it is important to notice it,  as  the error is generally
adopted—appears to be, that where  the food of the animal
contains much nutriment in a small bulk, there the stomach
and intestinal canal are simple and short;  but  where,  on
the contrary, it  contains  little nutriment in a large  bulk,
there great capacity,  complexity, and  length become re-
quisite to enable the animal  to elaborate a sufficiency  of;
nourishment for its  subsistence, by taking in the requisite
quantity from which  it is to be derived.   Accordingly, in
the elephant and some other herbivorous animals we find
the capacity to depend, not on the length, but on the  width
and  increased surface of  the intestine,  or, in other words,
on the greater calibre of its cavity ; whereas, in some  fishes
which  live on  very concentrated aliment,  the intestinal
canal is not much more than the length of the body—thus
showing that the common opinion on the subject is utterly
untenable:
   Before concluding his  experiments on the agents em-
ployed in digestion, Dr. Beaumont made many observations
with a view to ascertain whether any increase of tempera-
ture occurs during that process.  By introducing a ther-
mometer with a long stem at the external opening into St.
Martin's stomach, both before and during chymification^he
succeeded in obtaining very accurate  information on this
                            11* 
126      dr. beaumont's general inferences.
 point.  In two or three of the  experiments the heat of the
 stomach seemed to be increased after taking food, but in
 by far the greater  number the temperature remained  the
 same.  It appears, however, that the variations of the at-
 mosphere  produce a sensible  change on-the heat of  the
 stomach—a dry air  increasing and a moist air diminishing
 it.   The ordinary temperature may be estimated at  100°
 Fahr., and in several instances it was higher at the pyloric
 than at the cardiac end.  On one cloudy, damp,  and rainy
 day the thermometer rose only to 94°, and on another  to
 96° ; whereas next day,  when the weather was clear and
 dry, it rose to 99°, and on that following, when the weather
 was both clear and cold,  to 100°.  On several occasions it
 rose as high  as 102°, and once to 103° ; but these were
 after exercise, which was always observed to cause an in-
 crease of two'or three degrees.   We have already seen that
 artificial digestion is entirely arrested by cold, and is re-
 sumed on raising the temperature to ordinary blood-heat.
   Such, then, are the phenomena and conditions of healthy
 digestion, and such is the light thrown  upon them both
 by  the valuable publication of  the American  physiologist.
 Before leaving this branch of the subject, however, it may
 be  useful to lay before the reader, as a kind  of summary,
 the principal inferences deduced by Dr. Beaumont from his
 numerous experiments and observations. But in doing so I
 shall attempt to arrange the results in their natural order;
 for in the original work they are given without  reference
 either to logical sequence or to time.

  INFERENCES FROM DR. BEAUMONT'S EXPERIMENTS AND
                    OBSERVATIONS.*
 1. That hunger is the effect of  distention of the  vessels
       that secrete the  gastric juice.
 2. That the  processes of mastication, insalivation,  and
       deglutition, in an abstract point of view, do not in
       any way affect  the digestion  of the food ; or, in
 * The inferences are given in Dr. Beaumont's  own words, and
the italics also are his. It is needless to say that Dr. Beaumont does
not  present these inferences as  discoveries. Most of them  were
known before ; but he has the merit of adding greatly to the strength
of the evidence on which they rest, and of substituting certainty
for doubt in many instances. The very title of " Inferences " which
he modestly gives them, implies that he does not even consider them
as proved, and still less as discoveries ; although a learned review
erof the first edition charges him with this presumption. 
         BR.  BEAUMONT^S GENERAL INFERENCES.      127

      other words, when food is introduced directly into
      the stomach in a finely divided state, without these
      previous steps, it is as readily and as perfectly di-
      gested as when they have been taken.
3. That saliva does not possess the  properties of an ali-
      mentary solvent.
4. That the  agent of chymification is the gastric juice.
5. That the pure gastric juice is fluid, clear and  transpa-
      rent ; without odour ;  a little salt; and perceptibly
      acid.
!6. That it contains free muriatic acid,  and some  other
      active chemical principles.
 7. That it is never found free in the gastric cavity ; but
      is always excited to discharge itself by the intro-
      duction  of food or other irritants.
8. That it is secreted from vessels distinct from the mu-
      cous follicles.                               i
9. That it is seldom obtained pure, but is generally mixed
      with mucus,  and sometimes  with saliva.   When
      pure it is capable of being kept for  months, and per-
      haps for years.
i. 3. That it coagulates albumen, and afterward dissolves the
      coagula.
11. That it checks the progress of putrefaction.
12. That it  acts as a solvent of food, and alters its pro-
      perties.
13. That, like  other chemical agents, it commences its ac-
       tion on food as soon a3 it comes in contact with it.
14, That it is capable of combining with a certain and fixed
       quantityof food, and when more aliment is present-
       ed for its action than it will dissolve, disturbance of
       the stomach, or  " indigestion," will ensue.
15  That its  action is facilitated by the warmth and motions
       of the stomach.
16  That it becomes intimately mixed and blended with the
       ingestae in the stomach by the motions of that organ.
17. That it is  invariably the  same substance, modified oniy
       by  admixture with other fluids.
•18. That the motions of the stomach produce a constant
        churning of its contents, and admixture of food and
        gastric juice.
19. That these motions are in two directions, transversely
        and longitudinally. 
128     dr. Beaumont's- general inferences.

20. That no other fluid produces the same effect on foorj
       that gastric juice does;  and that it is the only sol-
       vent of aliment.
21. That the action of the stomach and its fluids is the same
       on all kinds of diet.
22. That solid  food, of a certain texture, is easier of di
       gestion than fluid.
23. That animal and farinaceous aliments are more easy
       of digestion than vegetable.
24. That the  susceptibility of digestion  does not, however,
       depend altogether upon natural or chemical distinc
       tions.
25. That digestion is-facilitated by minuteness of division
       and tenderness of fibre; and retarded by opposite
       qualities.
26. That the ultimate principles of aliment are always the
       same, from whatever food they  may be obtained.
27. That chyme is homogeneous, but variable in its colour
       and consistence.
28. That, toward the latter stages of chymification, it be-
       comes more acid and stimulating, and' passes more-
       rapidly from the stomach.
29. That the inner  coat of the stomach is of a pale pink
       colour, varying in its  hues according to its full or
       empty state.
30. That, in health,  it is sheathed with mucus.
31. That the appearance of the interior of the  stomach, in
       disease, is essentially different from that of its healthy
       state.
32". That stimulating condiments are injurious to the healthy
       stomach.
33. That the use of ardent spirits always produces disease
       of the stomach if persevered in.
34. That water, ardent Spirits, and most other fluids, are
       not affected by the gastric juice, but pass from the
       stomach soon after they have been received.
35. That the quantity of food generally taken is more  than
       the wants of the system require  ; and that such ex-
       cess, if persevered in, generally produces, not only
       functional aberration, but disease  of the coats of
       the stomach.
36. That bulk as well as nutriment is  necessary  to the-
       articles of diet. 
NATURE of CHYLIFICATION.
lira
37. That bile is not ordinarily found in the stomach, and is
       not commonly necessary for the digestion  of the
       food ;  but,
38. That when oily food has been used it assists its digestion.
39. That  oily food is difficult of digestion, though  it con-
       tains a large proportion of the nutrient principles.
40. That  the digestibility of aliment does not depend  upon
       the quantity of nutrient principles that it contains.
41. That  the  natural temperature of the stomach is about
       100° Fahrenheit.
42. That the temperature is not elevated by the ingestion
       of food.
43. That exercise elevates  the temperature ; and  that sleep
       or rest, in a recumbent position, depresses it.
44. That gentle exercise facilitates  the digestion  of food.
45. That the  time required for that purpose is various, de-
       pending upon the quantity  and quality of the food,
       state of  the stomach, &c.;  but that the time ordi-
       narily required for the disposal of  a moderate meal
       of the fibrous  parts of meat, with  bread,  &c, is
       from three to three and a half hours.
   A few more inferences are given, trht are here  omitted
because  they refer exclusively to the chyle, which  has not
yet been treated of.   The first is  probably erroneous, and
the second and seventeenth are, perhaps, too strongly ex-
pressed.   A complete change of diet, for example, causes
some variation in the gastric juice, although the latter in-
ference, taken in a literal sense, affirms the contrary.

                     CHAPTER  VI.
    CHYLIFICATION,  AND THE ORGANS CONCERNED IN IT.
Chyliflcation—Not well known—Organs concerned  in it—The
  intestinal canal—Its general structure—Peritoneal coat—Mesen-
  tery—Muscular coat—Uses of these—Air in intestines—Uses of
  —Mucous coat—Analogous to skin—The seat of excretion  and
  absorption—Mucous glands—Absorbent vessels—Course of chyle
  toward the heart—Nerves of mucous coat—Action of bowels ex-
  plained—Individual structure of intestines—The duodenum; jeju-
  num ; and ileum—Liver and pancreas concerned in chyliflcation
  —Their situation and uses—Bile, its origin and uses—The pan-
  creas—Its juice—The jejunum described—The ileum ; ccecum ;
  colon ; and rectum—Peristaltic motion of bowels—Aids to  it—
  Digestion of vegetables begins in stomach, but often finished in the
  bowels—Illustration from the horse—Confirmation by Dupuytren.
    The  conversion  of food into chyme, an operation which,
 2.6 we have  seen, takes place in the stomach, is only one 
 K39           NATURE OF CHYLIFICATION.

 •f the series of changes which aliment undergoes before-
 becoming fit to be assimilated with the living  body ; and
 the next process which we have  to notice is chyliflcation,
 er that by which, chyme is converted into chyle.
   In  proportion as chyme is formed from the  food, it is.
 gradually  propelled, as already shown, through the pyloric
 orifice of  the stomach into the duodenum or beginning of
 the small intestine.   On its arrival  there it is acted upon
 by the bile from the liver and the  pancreatic juice from the
 pancreas;  and  the result is the separation of the chyme
 into two distinct substances—the one a milky-white fluid
 called chyle, which is absorbed into the system, and forms
 nutriment; and the other a yellowish and more consistent
 mass, which is the  indigestible  remains of  the food, and
 which, after traversing the whole length of the intestinal
 canal, and being  there mixed with the waste matter sepa-
 rated  from,the blood in order to-be thrown out  of the system
 through the same channel, is at  last expelled in the form
 of faces or excrement.
  If physiologists experience much difficulty in satisfactorily
 explaining all the phenomena of  chymification  or  stomach
 digestion, the reflecting reader will not be surprised to learn
 that they are  still more puzzled to account for those of
 ehylification or intestinal digestion.  The organs concerned
 in the latter are so deep-seated and inaccessible during
 life, that very few opportunities occur of obtaining accurate
 information on  the subject; and, therefore, in what follows,
 I shall not enter into disputed or  intricate details, but con-
 fine myself to such general views as are not contested, and
 as the reader  may easily understand.  Fortunately, igno-
rance of this branch of the inquiry is of less practical  inv
portance than  if  it extended to stomachic digestion also ;
because such is the  harmony between all the parts-of  the
 system, that whatever conduces to the perfect accomplish-
ment  of the first stage of the process, chymification, is in so
far equally conducive  to the proper fulfilment of ehylifica-
tion or intestinal digestion.
  The simple fact, indeed, of our having no direct control
 over the process of ehylification, and  of our being able to
modify it only by varying, through the medium of the sto-
mach, the  elements out of which chyle is to be formed and
the mode in which they shall be digested, is  a proof that,
practically  speaking,  it is chiefly the laws or conditions of 
INTEST1NAT. CANAT..               131
 stomachic digestion which are intended to regulate our con-
 duct ; and that, in obeying them, we in reality obey also
 those of intestinal digestion.
   The organs concerned in ehylification are the duodenum,
the liver, and the pancreas ; but, in order to avoid repetition,
 I shall, in describing  the first, notice also the remainder of
 the intestine.
   The intestine or intestinal canal,  as represented in the
 subjoined figure, begins at the pyloric orifice of the stomach
 P, and after many windings and turnings, called convolutions,
■(from the Latin word  convolutus, rolled or folded together,)
 terminates in the rectum or straight gut  Y, at the external
 orifice, called the anus.  Although  continuous throughout
 its whole extent, the intestinal tube is, nevertheless, divided
 by anatomists into six portions, to each of which a different
 name is assigned : the distinction between some of these
is more nominal than reaj, but it still continues to be made
 on account of its convenience.
   The first grand division is into the small and great intes-
 tines ; the former beginning at the stomach, including  all
the convolutions marked R S S S S—and the latter begin-
 ning at T, where the  small intestine terminates, and inclu-
 ding the large gut  U TJ U U X Y Y, which surrounds, and
 is partly hidden by, the other bowels.
   The  small intestines, again, are  subdivided into three
 portions—the duodenum, the jejunum, and the ileum ; and
 the larger, in like manner, into three portions—the caput
 ccecum or simply  the caecum,  the colon, and the rectum.
 Of the whole length, the small intestines constitute by much
 the greater part, and  they differ somewhat from the larger
 in function as well as in magnitude.
   In structure, the intestines  exhibit a great analogy with
 the stomach.  They  consist, in common with it, of three
 coats or layers of membrane ;  the outer or peritoneal—the
 middle or muscular—and  the internal, mucous, or villous.
   The peritoneal coat is  the white,  firm, smooth, shining,
 and moist membrane, seen on the outside of the intestine
 on opening  the cavity of the abdomen.   It serves both as
 a support and as a medium of attachment to fix the intes-
 tine in its place.   By its smooth, soft, and  lubricated sur-
 face, it admits readily of the change of place among the bow-
 els necessarily produced by respiration, exercise, and even
 by different degrees of distention of the bowels themselves. 
 
              INTESTINE--THE MESENTERY.          133

Every time we breathe an undulating  motion is commu-
nicated to the whole intestines, which facilitates their action,
but which could not take  place unless  they were capable
of gliding  easily and freely over  each  other.   The peri-
toneal coat, being  strong, extensible, and elastic, is very
useful also as a support to the other coats.
  The peritoneal coat, after forming the outer covering of
the intestine, represented by the dotted line round the circle
I in  the  subjoined figure, is continued from it in  the
form of a  double membrane (represented by the two dotted
lines)-toward the spine S, to which it is first firmly attach-
ed by cellular substance;  after  which the folds again se-
parate, each being continued or reflected, as it is called, over
the whole  inner substance of the cavity of the abdomen
                                   in the  course shown
                                   by the dotted line, the
                                   figure itself represent-
                                   ing a transverse sec-
                                   tion of the abdomen.
                                   By this arrangement
                                   two importantobjects
                                   are attained.  First,
                                   the abdominal perito-
                                   neum AP forms a soft
                                   lubricated surface cor-
                                   responding to that of
the bowels themselves ; and, secondly, a firm  point of  at-
tachment  for the bowels is secured, by which they may  be
supported in their proper places, and at the same time ad-
mit of some change of position.   The floating portion of the
peritoneum M, by which the attachment is effected, is called
the mesentery, (from fieoog, mesos, the middle,  and evrepov,
enteron, intestine.)   But the intestinal canal being so much
longer than the portion of the spin* to which the mesentery
is attached, the latter is necessarily disposed in folds con-
verging toward  the spine, something  like the  folds  of a
fan converging toward its narrow end.  In this way the me-
sentery, besides serving as a support to the gut, serves also
to receive  and afford protection to the numerous  vessels,
nerves, and lacteals which are copiously ramified on every
portion, particularly of the  6mall intestines.  This feature,
however, will be better understood by inspecting the wood-
cut on page 138, representing a portion of the  bowel 11,
                          12
 
134          INTESTINE—MUSCULAR COAT

as attached to the 3pines by the mesentery M M, along which
the absorbent vessels or lacteals LKL are seen to pass from
the gut toward the thoracic duct T D.
   The portion of peritoneum by which the small intestines
are fixed to the  spine,  constitutes what is properly called
the mesentery.   That portion by which the larger  bowel is
attached is called the mesocolon, from its enclosing the colon;
but in other respects the membrane  presents no difference.
   The muscular coat is composed principally of transverse
and longitudinal fibres, and  its sole object  here,  as else-
where, is to effect motion.   By the alternate contraction of
the two kinds of fibres, the contents of the gut are  gradual-
ly propelled in a downward direction, just as we see a
motion propagated from one  end of a worm to the other;
and hence  it is sometimes called the vermicular or worm-
like motion, (from vermis} a worm.)  Some nauseating sub-.
stances, such as emetics, have  the power of inverting  the
order of the muscular  contractions, and directing  the, con-
tents upward instead of downward—whence vomiting ulti-
mately arises.   Other  substances, again, have the property
of exciting the natural action to a higher degree,  and con-
sequently propelling the contents faster downward—in other
words, of purging.   Rhubarb, aloes, and similar laxatives,
especially when  combined with tonics, act in this way, and
are, consequently, best adapted for obviating the  kind of
costiveness which arises from imperfect intestinal  contrac-
tion.   In a natural mode of life the muscular coat  is great-
ly aided in its operation by the large  abdominal and thoracic
muscles, brought powerfully and frequently into play during
active exercise and employments.    When this aid is with-
drawn, as it is in sedentary people,  the intestinal action
often  proves insufficient for  the purpose; and.hence  the
costiveness which is so invariable  an attendant  on most
females, literary men, and others, whose occupations deprive
them of active muscular exercise in the open air.   In fe-
males the use of tight  stays  renders the free expansion of
the chest and corresponding motion  of  the abdomen  al-
together impossible,  and thus aggravates the evils of their
sedentary mode of life.   Hence also the peculiar fitness, in
such cases, of the class of purgatives above alluded  to, in
preference to those of a saline nature, which act chiefly by
stimulating the mucous surface to farther secretion.
   In addition to the ordinary longitudinal  and transverse 
INTE8TINE—MUCOUS COAT.
135
 fibres, the colon presents three remarkable muscular bands
 running along its whole  length, and one of which is repre-
 sented  on the colon in  the figure  on page  132.   On the
 rectum all the three  bands are  seen.   It is in the colon
 and rectum that the feculent matter accumulates before it
 is thrown out of the  bowels, and  these bands  are useful
 chiefly by adding to their propelling power.
   The natural tendency of muscular fibre being to contract,
 it may  naturally be supposed  that, after the intestine  is
 emptied, its opposite sides will come into contact, and, by
 thus obliterating the cavity altogether, present an obstacle
 to the subsequent passage of any solid  matter.   But, on
 inspecting the abdomen after death, we rarely meet with
 any considerable portion thus contracted ; and, in general,
 the  whole intestines  are distended to  a greater or  less
 degree, according to circumstances.  The agent by which
 this effect is brought about,  is one known more  familiarly
 by the inconveniences and pain to which it gives  rise when
 in excess, than by its proper uses, which are, nevertheless,
 important.  I allude to the  presence of  air in the bowels,
 which is  as necessary  to  their healthy action  as  their
 muscular  contraction itself.   Air, in fact, by its expansive
 energy, forms the  antagonist power to the muscular coat,
 and serves to dilate the bowel after the requisite contraction
 has propelled its contents.  A certain degree of distention,
indeed,  not only  is a stimulus to farther muscular con-
traction, but is useful in facilitating the passage of the
subsequent portions of  the  feculent matter ;  and hence
the injection of air into the bowels in  large quantity has
lately been employed successfully in overcoming obstinate
constipation.
   The  mucous, internal, or villous coat of the  intestine,
also resembles in many respects that of the stomach.  It is a
 soft, velvety membrane, full of wrinkles or folds through the
greater  part of its course, by means of which its  surface is
 greatly increased  in extent, so  as to afford ample space for
 the ramification of the bloodvessels, nerves, and absorbents,
 with which it is very  plentifully supplied.  The cut on  p.
 145 will convey some idea of its appearance, as seen in the
 smaller intestine.   So far as nutrition is concerned, the
 mucous coat is the truly essential  part of the bowel.   It
 alone is in direct  contact with the chyme, and in its cavity
 the bile and pancreatic juice perform their respective parts, 
 136           INTESTINE—MUCOtJS COAT.

 and give rise to the formation of chyle, which is afterward
 transmitted from its surface into the general system.  The
 peritoneal and muscular coats are  useful only in affording
 protection, and communicating the power of propelling its
 contents.
   The mucous coat appears, on examination, to be so entire-
 ly continuous with the skin, that no line of demarcation can
 be detected between them, either at the mouth or at the
 anus.   In structure they greatly  resemble each other, and
 the sympathy between them is well known to be very rapid
 and intimate.   Eruptions on the skin, for  example, are
almost always owing to disorder of the digestive  organs ;
 and bowel-complaint, on the other  hand, is often produced
by a sudden chill on the surface.   In like manner, in enor-
mous  eaters, like those formerly mentioned, an immense
exhalation takes place from both  the skin and the bowels,
 and in many  instances the one supplies  the place of the
 other in a considerable degree.  We have seen, moreover,
 that in the lowest  tribes of animals the digesting surfaces
 and skin are  not only  undistinguishable, but actually con-
vertible into each other by the simple process of turning the
 animal inside out, when each will perform the function of
 the other as well as if it had never done anything else.
   In  common with the  skin,  too, the  mucous coat  is
 charged with the double function of excretion and absorp-
 tion.  For the former,  it is eminently fitted by its  plentiful
supply of blood, and by the great number of minute vessels
ramified on its surface, from the extremities of which the
excretion takes place.   It is by this channel that  much of
the waste matter requiring to be  removed from the body is
thrown out.  Being poured into the cavity of the  intestine
from the small arterial branches, it mixes there with the
indigestible residuum of the food  and bile, and, united with
them, forms the common fa?ces or excrement.  When the
blood  is suddenly repelled  from the surface by a chill, and
 thiown in upon these vessels  in large quantity, the natural
excretion is sometimes increased to  such an extent as to
 constitute bowel-complaint;  while, at other times, that
 peculiar form of action  is induced which constitutes inflam-
 mation.   The local stimulus of some  kinds of food, and
 of many medical substances, also excites the secretion to
 unusual activity.  Salts, for instance, have this effect, and
 thus often produce numerous fluid evacuations, the sub- 
               INTESTINE—MUCOUS COAT.            137

stance or materials of which did not before exist  in the
bowels ; and hence the  mistake  into which many fall, of
taking more medicine on the ground of this effect proving
that much stuff was lodged  in the bowels—when, in  fact, it
was not only removed but created  by the physic.  It is from
exciting  a fluid discharge  of this description, that  salino
purgatives are so useful for lowering the tone of the system
when that is required ; but, for the same reason, they are
most improper where relaxation and debility already  exist.
In Asiatic cholera almost the whole fluids of the bodyare
carried off by this channel,  leaving the blood too thick in
consistence to circulate longer through the smaller vessels.
  The excretions from the  minute arterial  branches rami-
fied on the internal coat are  mingled with a bland fluid from
the mucous follicles, the evident use of which is to protect
from injury the sensitive surface  of the intestine.   Occa-
sionally,  however, the mucous secretion becomes so  abun-
dant and viscid as to adhere with unusual force, and to
impede the formation and absorption of the chyle, and even
the action of the usual purgatives.  Worms are then com-
mon, and cannot be  expelled, except  by remedies  which
tend to remove the mucus in which they live imbedded.
  To fit the  mucous coat for its office of absorption, an
immense number of minute vessels, called  absorbents, are
ramified on its internal surface, the nature and purposes of
which  are analogous  to those  mentioned in the former
volume  when  describing the functions  of the skin.*  In
both structures the  absorbents are small capillary or hair-
sized vessels, so infinite in number that at least one goes
to every little point or papilla.   Those which open upon
the inner surface of the smaller intestines, and which suck
in or absorb the  chyle,  are called lacteal absorbents, or
simply the lacteals or milk-vessels, (marked LLLL  in the
subjoined  wood-cut,) from  the white  colour of the   chyle
shining through them and giving  them the  appearance of
vessels full of milk.   In  that part of  the gut they are so
numerous that every minute point of  the villous coat may
be seen, by the aid of a microscope, to contain one with its
mouth open to receive the chyle as  fast as it is formed.
Even in the colon  the absorbents are  numerous ; but, as
all traces of chyle have there disappeared, they are  much
fewer than in the smaller intestines.   In the colon they
           • Principles of Physiology, &c, chap. ii.
                        12* 
138   INTESTINE—MUCOUS COAT—ITS ABSORBENTS.
serve chiefly to remove  the  more  watery portions of the
intestinal contents, by which means the faeces are rendered
                        TD
more solid and less bulky, and, therefore, better adapted for
being retained for a time without inconvenience.  It some-
times happens that, when food or medicine cannot be swal-
lowed in the usual way, life is preserved by injecting it into
the bowels ; in which case the absorbents of the large gut
become active, and carry it into the system.  Strong soups,
milk, opium, laxatives, and other remedies are  often admi-
nistered in the same way, when any reason exists  against
giving  them by the mouth.
  There are absorbents in every structure of the body,
because there are everywhere waste particles  to be taken
up and removed;  but, except in the case of the lacteals,
their contents are limpid or colourless, and hence in other
places  they are called  lymphatics : in almost  every other
respect, however, the two classes of vessels are analogous
to each other.
  The peculiar property by which the minute  lacteal ves-
sels imbibe or take up the white chyle is not well  understood.
From the fact in physics, that liquids rise in capillary tubes,
the  inference  has been drawn that absorption  in living 
INTESTINE—MUCOUS COAT—ITS ABSORBENTS.   139
Vessels also takes place from capillary attraction.  But in
the animal body the application of the principle is undoubt-
edly modified by the properties peculiar to organization,
and one of the most remarkable proofs of this is the circum-
stance of the absorbent vessels in different situations having,
to some extent, a specific adaptation to the qualities of the
substances upon which they are severally destined to act.
At one time, indeed, it  was supposed that the principle of
exclusive adaptation was so complete that every absorbent
vessel was permanently shut to everything except its own
                              peculiar object, and  that,
                              from amid many elements,
                              each selected its own with
                              unerring tact.  But of late
                             j it has been proved that the
                              absorbents  are less rigidly
                              discriminating than  was
                              previously  supposed,  and
                              that substances are readily
                               taken up by them which
                              Nature   never  intended
                              them to receive.  In mix-
                              ing madder with  the food
                              of fowls, for example,  for
                              the purpose of dying their
                              bones, the colouring mat-
                              ter of the root is taken up
                              without difficulty  by the
                               absorbents  along  with the
                               chyle,   although  madder
                               was certainly never intend-
                               ed to be their natural sti-
                               mulus.  But even admit-
                               ting  this  latitude in  its
                               fullest extent, there  still
                               exist a  fitness and pecu-
                               liarity of relation between
                               the absorbents and  their
                               proper objects, which ren-
                               ders the latter more acces-
                               sible to them than to any
                               foreign  body.
                                  The lacteal vessels  are
 
 140  INTESTINE—CONVERSION OF CHYLE INTO BLOOD.

 most easily seen an hour or two after a meal;  because they
 are  then  fully distended with chyle, even in their smaller
 branches.  The  latter, indeed, may then be distinctly traced
 proceeding from the different  portions of intestine, and gra-
 dually coalescing into larger  trunks, as seen  at L L in the
 figure  on p. 138.  These,  again, terminate  in the vessel
 called the thoracic duct, (the  beginning of which is seen at
 TD in the same figure,) by which the chyle is conveyed al-
 most in a direct course along the spine, and which "is repre-
 sented at  D D D D in the cut on p.  139.   On its arrival at
 the upper part of the chest, the thoracic duct crosses over
 and  opens into the subclavian vein  S, just before the latter
 reaches the right side of the heart, so that the chyle is there
 poured into the circulating current  of the venous blood.
   Such is the course of the chyle.   But the  lacteal absor-
 bents, in their progress from the intestine to the thoracic
 duct, pass through the small glandular bodies called the
 mesenteric glands, (M G, p.  138,) where some change, the
 nature of which is not at all understood, is produced upon the
 chyle, but which seems,  nevertheless,  to be of importance
 to its constitution.   Where these glands are hardened and
 enlarged,  as they often are in scrofulous children with large
 prominent bellies and thin  bodies, nutrition is  greatly im-
paired, although  the appetite and stomachic  digestion re-
main comparatively unaffected.
   The reason why the chyle  is carried so far, to be poured
into  the current  of the venous blood just before the  latter
reaches the right side of  the heart, is, on consideration,
 not less obvious than cogent.   Chyle itself is not fitted to
become a  constituent part of the animal frame.  Before it
can become so it must be converted intoblood; and this can
be effected only  by exposing  it to the  action of the  air in
the air-cells of the lungs in a  state of intimate mixture with
the venous blood.  This admixture, again, is ensured by
 the gradual way in which the chyle advances along the
 thoracic duct and falls into the circulating current almost
 drop by drop ; and it takes place just before the dark blood
 has finished its course, and is again subjected to complete
 aeration in its passage through the lungs.  As explained in
 the former volume, this aeration is  so indispensable to the
 renovation of the old and the formation of new  blood, that
 whenever it is rendered imperfect, either by obstructions
 in the lungs themselves or  by the absence of a sufficiently 
     INTESTINE—CONVERSION OF CHYLE INTO BLOOD.  141-

 pure air without, the result is invariably injurious to health;
 because  the blood, being no  longer  properly constituted,
 becomes incapable of furnishing  a healthy  stimulus and
 nourishment to all the parts of the body.  Hence the rapid
 " decline"  which follows  the appearance of  pulmonary
 consumption, and other diseases affecting the structure and
 interrupting the  functions of the lungs.
   Everybody knows as a fact that bad  air is hurtful, and
 that wasting disease of the lungs is attended with rapid loss
 of flesh and strength ; but the manner in which these effects
 are produced is  not so familiarly known.  Yet, in a practi-
 cal point of  view, a knowledge of the principle is highly im-
 portant.   Properly considered, respiration is in reality the
 completion of digestion.   The stomach may convert the
 food into chyme,  the small intestines  may convert the
 chyme into  chyle, and the absorbents may take up the latter
 and duly convey  it into the circulating system ;  but, unless
 it undergo the necessary change in the air-cells of the lungs,
 it will not constitute good blood nor afford due nourishment
 to the body.  Hence it is that  those among the working
 classes who are  much confined in an impure and insalubri-
 ous atmosphere, even when plentifully supplied with food,
 are generally thin and ill nourished ; and hence those who,
 along with good  digestion, have small narrow  chests and
 very limited respiration, are commonly found to be consti-
tutionally lean—while those who, along with good digestion,
have amply  developed lungs and free and powerful respira-
 tion, are at the same time remarkable for proportional
vigour of nutrition and stoutness of body.  It is on this ac-
 count that in chronic pulmonary  disease recovery is always
 to be distrusted, unless,  along with the disappearance of
 the prominent symptoms, restoration of the ,lost flesh occurs.
 If nutrition remains impaired, however great the relief may
be in other  respects, there  is reason to believe  that the
 lungs are still so  extensively diseased as  to injure their
 functions, and that, on the application of any fresh exciting
 cause, the dormant mischief will resume its  activity.  In
 such cases,  when stomachic digestion is sound, a full diet
 generally over-stimulates the  system, by pouring into the
 blood more chyle than the lungs  are able to assimilate ;  in
 consequence of which it is diffused over the whole body in
 an imperfect state of preparation.
   The mucous  membrane is, like the skin, well provided 
142
INTE3TINS—DUODENUM •
with nerves, and has a mode of sensation peculiar to itself.
Every villous point, indeed, has a nervous fibre ramified on
it, to give it the necessary sensibility to its own stimuli.
It is true, we are not conscious in health of the impressions
made on the intestinal nerves; but this, as already shown
in describing  the stomach, is  a privilege and not a defect.
They recognise their  appropriate  stimuli,  and cause the
necessary actions to follow without requiring aid from the
will.  But when they meet with substances which ought
not to be there, such as pieces of undigested food, or foreign
bodies which have no natural relation to their constitution,
they immediately indicate uneasiness, and excite the mus-
cular contractions to rid them of the offending cause.
   To secure full and natural action in the intestinal canal,
several principal conditions are  thus necessary, failure of
any of which may impair their activity.   The first condition
is well-digested chyme and chyle ;  the second, a due quan-
tity and quality of mucous and vascular  secretions from the
villous coat; the third, full contractile power  in the mus-
cular fibres of the intestine, and free action of the abdominal
and respiratory muscles; and the last, a due nervous sensi-
bility to receive impressions and communicate the necessary
stimulus. And hence, when the bowels act imperfectly, it is
of importance to ascertain to  what cause the inability is to
be ascribed,  that an appropriate treatment may be devised.
   Such are the general structure and uses of the intestinal
canal; but there are modifications in its individual portions,
on which it may be right to offer a few additional  remarks.
We shall begin with the duodenum.
   The duodenum (from duodeni, twelve, being considered
equal in length to twelve finger-breadths) commences at the
pyloric orifice of the stomach, from which it  crosses over
under the lower surface of the liver, toward the right side ;
it then descends in front of the right kidney, and there form-
ing a  second  curve,  it proceeds  again toward  the left, and
a little beyond the spinal column terminates in the,  jejunum.
It thus describes a course like the letter C, and has its con-
vexity turned toward the right, while the pancreas or sweet-
bread (P P)  lies in  the space  enclosed by its concavity.
To enable the reader to form some  notion of the relative
position  of these parts, I have  introduced  a wood-cut  on
the next page, showing the situations  and appearance of
the different organs after the intestines, as in  the figure on 
 
144             INTESTINE—DUODENUM.
 page 132, have been removed from the body.  The letters
 LLLL point out the inferior surface of the liver,  a little
 raised from its natural position to show the gall-bladder G
 and the pancreas P P, round the  right end of which  the
 duodenum is curved.   S indicates the spleen, with a vacant
 space over it, in which the stomach  lies.  The kidneys K
 K  lie one on each side of the spine;  and the two pipes
 UU are the ureters which convey their secreted fluid  to
 the bladder B.  The letters A A indicate  the great  artery,
 (the aorta,) through which the nutritive blood  descends to
 supply the bowels and lower parts of the  body ; and V V
 mark the corresponding vein, (the cava,) by which the dark
 blood returns  from the extremities toward  the heart.  R is
 the beginning of the  rectum or straight gut seen at Y Y in
 the cut on page 132.
  The duodenum, being'thus  in the immediate vicinity of
 the spine, is fixed firmly down in its position  by the con-
 necting membrane, and is not left to float  loosely in  the
 cavity of the abdomen or belly.  Had it not been  tied
 down in this  way, it  would not only  have acted  by its
 weight as a continual drag upon the stomach and disturbed
 its  functions,  but likewise have been constantly altering
 its  own  relation  to  the  pancreatic and hepatic  (or liver)
 ducts, and thereby  affecting  the flow  of  their respective
 fluids into its cavity,  by which the chyliflcation  would
 have often been interrupted.
  The duodenum is much smaller in diameter  than the
 stomach, but  large than  the  jejunum or ileum; and  its
muscular coat is also thicker.   From its size and the  im-
portance of the changes effected in it, it has been con-
sidered  by some  as  a  secondary stomach or  ventriculus
succenturiatus.  Its mucous coat, which has a soft velvety
feel, presents a greater multitude of  the folds or  plaits  al-
ready described, and which have for their object to extend
its surface and delay the passage  of the  chyme.   Some
notion of their appearance may be formed from  the sub-
joined wood-cut.  These folds or ruga are called valvula
conniventes or folding valves, and are inherent in the na-
 ture of the mucous coat, and not produced by  mere folds
 of the whole  thickness of the intestine, consequently they
 exist even  when the latter is distended.  They are com-
 paratively few  in number in the part of the  duodenum
 near the stomach, and  gradually multiply in  the  course 
                 DUODENUM AND LIVER.              145

downward till they arrive at the maximum of developement
at its lower end and in the jejunum : they again diminish in
the ileum, and disappear altogether in the large gut.  The
bloodvessels and nerves of the  duodenum are extremely
numerous, and indicate the importance of its functions.
  The duodenum serves to receive the chyme as its issues
from the stomach, and  to prepare it for the farther changes
which it is about to undergo.  But as other organs, namely,
the liver and pancreas, are directly concerned along with
the duodenum in effecting ehylification, it will be proper
to take a cursory view of them  also before describing  the
rest of the intestine.
  The liver (LLLL, p. 143)  is a very large  glandular
body lying under the short ribs of the right side, immedi-
ately below the diaphragm or midriff, to which it is attach-
ed by strong ligamentary bands, which  sustain its weight
and keep it  in  its place.   Its office  is to secrete the bile,
but it differs in one  important particular from every other
secreting organ.   Its secretion is derived, not, as in other
instances,  from the arterial  or  nutritive blood,  but from
the venous or exhausted blood, which is collected from all
the abdominal organs, and transmitted  through  it for this
purpose on its way back to the heart.   From this pecu- 
146        THE LIVER—BILE—ITS NATURE.

liarity it is legitimately enough inferred, that the liver served
the double purpose of providing a fluid indispensable for
ehylification and the proper action of the  bowels as or-
gans of excretion, and also of separating from the venous
blood useless> or spent  materials,  which  require  to be
thrown out of the system.  The influence  of the bile as
a stimulant to the bowels is proved by the fact, that cos-
tiveness ensues when it is deficient  in quantity, and an
opposite condition  when  the  secretion is  redundant, as
during the heat of autumn.
  Bile is  a bitter, viscid, greenish-yellow fluid, the taste
and  general  appearance of which are familiar  to  most
people,  and the  office  of  which in the animal economy
must  be  one of no  small moment, if it be justly charge-
able with even a tenth part of the catalogue of human ills
which are laid  to its account.  Its secretion seems to go
on continuously ;- but the quantity produced depends much
on the amount of venous blood which is circulating through
the liver  at the time.  Hence, in health, it  is always
greatest soon after a meal; because, as we have already
seen, the supply of blood in both the arteries and the veins
connected with digestion is  then at its maximum.
  But as the secretion  of the bile is constantly going on,
and its presence  in  the duodenum' is required  only when
the latter contains chyme, a contrivance becomes requisite
for storing it up in the interval, to be ready for  use  when
wanted.  This is effected by the small shut sac or bag G,
named the gall  (or bile) bladder, which  adheres to  the
lower surface of the liver, and is always most full after  a
fast of some duration.   The bile contained in the gall-
bladder  is  generally more  viscid,  dark, and bitter than
that which  proceeds directly from the liver—apparently
from the absorption  of its more fluid parts.  It is in this
bag that gall-stones, as they are called, are sometimes form-
ed, and it is their passage through the narrow tube in which
it terminates that causes the acute pain so often complain-
ed of in that affection.
  From the livrr the bile is conducted into the duodenum
through a membranous tube, of about the  diameter of  a
qjuill, and which is called the biliary or hepatic  duct.  Iri
its course a similar pipe, called the  cystic dhtct,  (from
Kvarig, kystis, a bladder,) from the gall-bladder, unites with
it into one trunk, like the two limbs of the letter Y ; and 
               THE PANCREAS—ITS JUICE.            147

diis trunk enters the duodenum by an orifice common to it
and the pancreatic duct:
   In the healthy state bile is to be found only in the duode-
num, and not in the stomach ;  although one would suppose
the contrary from the familiar way in which we speak of
the stomach being oppressed with bile, and of our being
" very bilious."  When  vomiting is excited, either artifi-
cially or by illness, we, no doubt, often bring up plenty of
bile.  Sometimes this bile has been existing in the stomach
and causing nausea ;  but very often it is brought into the
stomach solely by the inverted action  which constitutes
vomiting,  and was consequently placed there by the very
remedy which is supposed to have cleared  it away.  The
process of vomiting is accompanied by  an  inverted action
of  the intestinal canal, whereby it propels its contents up-
ward  instead of downward, and thus the bile is, as it were,
forced from  the duodenum into  the stomach, instead  of
being propelled downward and  expelled in  the  usual way.
Hence, in sea-sickness, for example, the first fits of retching
generally  bring up nothing but food or mucus—the real
contents of the stomach—and it is  only after continued
straining  that  bitter bile makes its  appearance.   In  the
healthy state fat or  oily food often  causes the presence
of bile in the stomach, as if its aid were  necessary there for
the accomplishment of digestion.
   The pancreas,  or sweetbread, P P, is  a large  oblong
gland, which lies  across the spine,  and secretes  a fluid
almost identical with the saliva.   Its duct, as stated above,
enters the duodenum along with the biliary duct, so that
the two fluids meet at their entrance, which takes place at
the first curvature of the intestine, at the distance of about
one-third of its whole length from the stomach.
   The bile and pancreatic juice  thus poured out together
are both  requisite  for the formation of chyle, and  appa-
rently modify the action of  each other.   The  bile being
somewhat of an unctuous nature, and the pancreatic juice
somewhat alkaline, their union  forms  a kind of sapona-
ceous compound,  which is less irritating and more easily
incorporated with the chyme  than pure bile.
    In proportion as the chyme is  formed and expelled from
 the stomach, it is  received  into  the duodenum, where it
 probably  undergoes some farther change  even before  ar-
 riving at the entrance of the biliary and pancreatic ducts 
148          INTESTINE—JEJUNUM—ILEUM.

From the numerous folds or wrinkles which line the inner
surface  of  the  duodenum and impede  the  motion of its
contents, and also from the intestine itself being more fixed
down, and less subjected to the influence of the movements
of respiration, the progress of the chyme along its surface
is very slow.  Every particle  of chyme is thus allowed to
receive  its  share of the bile and pancreatic juice as  it
proceeds on its course, and time is afforded for the requisite
changes taking place.
  By simply stating that, in the duodenum, the chyma
becomes mixed with the two fluids just mentioned, and that
the result is its separation into a fluid, milky, and nutritive
portion, named  chyle, which  is absorbed by the lacteals,
and a darker yellow-coloured  thickish mass which remains
in the bowel, we communicate to the reader almost every-
thing that is known on the subject.   Theories and conjec-
tures could be added,  but scarcely any facts of a  very
positive nature.
  The remainder of the small intestine,, namely, the jeju-
num (from jejunus, fasting or hungry, because it is generally
empty) and the ileum? (from ei'Aeu, eileo, I twist or turn
about,) marked RSSSS  in the cut on p. 132, are  merely
continuations of the duodenum,  and have  precisely tha
same number of coats and  the same  general structure.
Their inner surface presents the same kind of folds or ruga,
whereby the extent  of the mucous membrane  is increased,
and ample  space given for the ramifications of bloodvessels
and the origin of the absorbents by which the chyle is sucked
up  and carried  into the system.   Exhalation or exudation
also goes on from  their  surface, and in bowel-complaints
often becomes so excessive as in a few days to reduce the
patient to the extremity of emaciation  and weakness.
  As the contents of the jejunum and  ileum  advance, the
proportion  of chyle in them becomes smaller and smaller,
and the residual matter becomes more and more consistent,
yellow, and fetid—approaching,  in  short, to  the ordinary
appearance of  excrement when expelled from the body.
In accordance with these changes, the number of absorbent
vessels and the distinctness  of the villous folds gradually
diminish as we proceed downward, till, on arriving at the
 termination of  the  ileum in  the colon or great gut, they
 altogether  disappear, and the  contents  assume the colour,
 smell,  and appearance- by which excrement or feculent
 matter is characterized.               '' 
INTESTINE--COLON.
149
  The division between the small and great intestines is
indicated, not only by marked differences in their diameter
and external appearance, but also by an internal valve placed
between them, the object of which is to prevent the contents
of the colon from following a retrograde course and return-
ing to the ileum.  It is also worthy of notice, that the colon
is not a gradually enlarged continuation of the ileum.  On
the contrary, the latter enters  the side of the colon  almost
at right  angles  to its course, at a little distance from its
commencement.   The small  portion of the celen  which
thus lies  at one side  of the  entrance  of the ileum, and
which has, of course, no opening at its extremity, is thence
called the caput caecum, coli, or blind head of the colon, or
simply the caecum.   Its position is at T in/the figure on p.
132, but it is hidden by the folds of the ileum.
  The colon, (from kol?i.ov, coilon, hollow,) or great gut UUU
in the  same figure, constitutes not more than one-fifth in
length of the intestinal canal.   It begins at the lower part
of the right side of the belly, at T in the cut on page 132 ;
rises  upward on the same side toward the liver;  crosses
over to the left side in  contact with the stomach ; descends
along the left side  ©f the abdomen ; makes a turn at UWX
like an italic s, (and hence called sigmoid flexure,) while
lying on  the left  haunch-bone ; and lastly, terminates in
the rectum or straight gut YY at the anus.   Being fixed
by local attachments, the colon remains always in the same
situation, and thus describes a figure not unlike a square,  s
in the centre of which lie the  whole of the smaller intes-
tines.   In the cut referred to the  left  portion  is  hidden
behind them.
   The  diameter of the colon  is about  double that of  the
small intestines.  In  structure it  is analogous to  them,
having three coats ;  but the valvula connivent.es,  or folds of
the mucous coat, are no longer to be seen, and with them
all traces of chyle and chyle-bearing vessels also disappear
The colon serves  more as a reservoir for waste or excre-
mentitio'us matter than as  a  vital organ.   Absorption is
carried on from its inner surface, but through the medium
of  lymphatic absorbents and minute venous ramifications,
and not of lacteals.  Hence not only food, but  medicine,
are frequently administered by being injected into the rec-
tum, and life has been saved in this way when nothing could
be given by the mouth.
                          13* 
 150   INTESTINAL DIGESTION OF VEGETABLE FOOD*.

   The passage of the intestinal contents from the stomach
 downward is affected chiefly by the peristaltic or vermicular
 motion, that is, the successive muscular contraction of the
 middle or fleshy coat, already frequently adverted to ; and
 this, in  its turn, is greatly aided by the constant, but gen-
 tle, agitation which the whole digestive apparatus receives
 during the act of breathing, and during exercise of every
 description.   In inhaling air into the lungs, the diaphragm
 is depressed, the bowels are pushed down, the walls of the
 belly  yield,  and  it  becomes protuberant.    When air is
 thrown  out from the lungs, the  diaphragm  rises into  the
 chest, the bowels follow, and the belly  becomes flattened
 and drawn in.   The stomach and bowels are thus placed
 between, and  receive a never-ending impulse from, two
 bodies differently placed and in continual motion.  During
 exercise breathing is deeper, and muscular contraction
greater in power  and in extent;  and hence the assistance
afforded is also increased.  Those who  take no  exercise,
 or who have the chest and bowels confined and bound down
by tight stays and bandages, lose this natural stimulus, and
 have, in consequence, the bowels obstinate and troublesome.
   The great extent  and capacity of the intestinal canal in
 herbivorous animals, and others living on bulky and innu-
tritions food, have been already noticed and their reason
explained.  Perhaps it ought to be added, that an additional
reason is the fact, that the digestion of vegetable  nutriment
is not, like that of animal food, completed in the  s'tornach,
but in the intestines.  It is familiarly known, for example,
that when digestion is weak, fruits and fresh vegetable ali-
ments often  pass  through the  bowels very little changed ;
and that, even at the best,  they  are digested more slowly
than animal food.  On examining the bodies of animals at
different intervals from the time of feeding, the distinguish-
ing fibrous structure of vegetable food is observed to dimi-
nish in proportion to its distance from the stomach, and it
does not finally disappear till it is nearly arrived at the end
 of its course.  From this  it has been  inferred, that  the
 digestion of vegetable matter is only partially accomplished
 in the stomach, and that it requires the aid of the intestinal
 juices for its completion.   Delabere Blaine  arrives at the
 same conclusion, from considering  the peculiar digestion
 of the horse.   In the horse the  stomach is a simple  bag,
 of very moderate size, and yet  that animal  not  only can 
        INTESTINAL DIGESTION OF ANIMAL FOOD.     151

drink a gallon or two of water at a time, but can eat a much
larger quantity of hay or grass  than its stomach seems to
be capable of containing.  Blaine explains this, by stating
that, in reality,  oats and hay are not  long retained in the
stomach, and that, after receiving the requisite  supply of
gastric juice, and  undergoing its influence to some extent,
they are gradually propelled toward the duodenum, where
their digestion  is continued, but not completed  till long
after being subjected to the action of the bile and pancrea-
tic juice, and passing through  the remainder of the small
intestine.   It is owing, he adds, to this speedy  evacuation
of the  stomach that the horse is less inclined to drowsi-
ness, and  less  incommoded by active exercise, soon after
meals,  than almost any other animal.
  The late  Baron Dupuytren had several opportunities of
observing something analogous to this in  the humam sub-
ject.  He  had, at various  times, under his care, patients
in whom an opening into the intestine had taken place at
different distances from the stomach, and through which
the intestinal contents readily escaped.   On giving several
kinds of food at one meal, he remarked that they presented
themselves at the wound in the  inverse order of their di-
gestibility.   Thus, fresh vegetables always  made their
appearance first,  still  retaining  much  of  their peculiar
structure ;  while animal substances  either did  not appear
at all, or were so much altered  in appearance  as scarcely
to be recognised.   In the natural evacuations, however, the
vegetable structure was generally imperceptible ; so that
a  considerable change must have taken place on it as it
advanced through the bowels, after passing the seat of the
wound.   Londe had occasion to remark the same thing in a
lady in whom an opening into the intestine existed.  When
she ate cutlets or chicken, digestion was so far  advanced
before they reached the opening, that their identity could
not be recognised.   But when she ate spinage, carrots, or
vegetable soups, these articles arrived at the orifice scarce-
ly at all changed.   In this patient also vegetable substances
passed rapidly out of  the stomach.   Thus salads, prunes,
apples, and spinage made their appearance at the opening
in about an hour; while the remains of animal food  never
appeared  in less than three hours.  Londe, indeed, lays it
down as a principle, that where the wants of the system are
not great,  the  digestion or alteration of  innutritious sub- 
S52
CONCLUDING REMARKS.
stances, such as stewed or raw fruits, carrots, &c, " begins
only in the ileum"  He adds, that he "has always seen
these substances resist the  action of the acid and mucous
juices of the stomach, as well as that oT the pancreatic and
biliary secretions."*
   From the circumstance of vegetable aliment containing
Utile nourishment and muck indigestible matter, it naturally
happens that a larger  quantity  of refuse  remains to be
thrown out of  the bowels  when it constitutes the chief
part of the diet, than when animal or farinaceous food,
which contains much nourishment and little  indigestible
matter, is  used.  Hence, as a general rule, the bowels act
more freely, or are more open,  in  the former than in the
latter case ; and hence the common saying, that milk, eggs,
jellies, and meat are binding.  They have  the appearance
of being so, chiefly because they are almost wholly absorb-
ed.   But as neither the stomach nor the bowels are adapt-
ed in structure for very concentrated food, such articles
cannot be  long used  with  advantage.   Brown and  rye
bread, and fruits, are in repute for relieving a costive habit
of body, and their usefulness  is  explicable on the same
principle.   They leave a large residue  to be thrown out of
the system, and this residue forms the natural stimulus of
the bowels, and, consequently, excites them to freer action.
This effect is probably aided also by the stimulus which the
indigestible refuse imparts to the  mucous  glands, increas-
ing the lubricating secretion, and giving additional facility
to the propelling powers.
   In the preceding exposition of  the  structure and func-
tions of the organs of digestion many omissions necessari-
ly occur, and many questions of much  intrinsic interest are
passed over with very little notice.   But a minuter survey
was incompatible with both the objects and the limits of
the work.   My great aim was, not so  much to extend the
bounds of physiology, but to turn to a useful purpose what
is already  known in  regard  to one of its  most important
departments, and to interest a larger class of people in its
cultivation.  If I have said enough to make the points of
doctrine on which  I have touched intelligible to the ordinary
reader, and to  impress him with a just sense of their prac-
tical value, 1 shall have accomplished the utmost I  have
sought to attain.                                    x
         * Londe, Elemens d'Hygiene, tome ii., p. 16. 
153
                      PART II.

THE PRINCIPLES OF DIETETICS VIEWED IN RELATION
            TO THE LAWS OF DIGESTION.
                     CHAPTER I.
                    TIMES OF EATING.
The selection of food only one element in sound digestion—Othe*
  conditions essential- Times of eating—No stated hours for eat.
  ing—Five or six hours of interval between meals generally suffi-
  cient ; but  must vary according to circumstances—Habit has
  much influence—Proper time for breakfast depends on constitu-
  tion, health, and mode of life—Interval required between break-
  fast and dinner ; best time for dinner ; circumstances in which
  lunch is proper ; late dinners considered ; their propriety depen-
  dant on mode of life—Tea and coffee as a third  meal; useful in
  certain circumstances—Supper  considered—General rule as to
  meals—Nature  admits of variety ; illustrations ; but requires
  the observance of principle in our rules.
   Having, in the first part of  the present work, traced the
progress of the food through its successive  stages  of pre-
paration for becoming a constituent element of the animal
frame, and examined the structure  and  nature of the vari-
ous  organs engaged in digestion, I shall now endeavour to
turn the exposition  to account, by making it, as  far  as pos-
sible, subservient to a closer and more rational observance
of the laws of digestion, and to a better adaptation of diet
and regimen to different ages, sexes, and constitutions, than
that which is generally prevalent.   I am deeply sensible of
the  imperfections which will  abound in  this part  of  the
work ;  but, at the same time, I am so strongly impressed
with the urgent importance of  the subject, and with  the
 success which will infallibly attend its farther investigation
 on sound physiological principles, that I consider the like-
 lihood  of personal failure to  be of secondary  importance,
 when compared  with the benefits which will accrue to
 society  from the exertions of others  whose labours  may
 be  more profitably directed by an acquaintance with  the
 guiding principles unfolded in these, pages.
   According to the popular notion of dietetics, the selection
 of the proper kind of food seems to be considered  the only
 condition required  for the  enjoyment of healthy digestion.
 Hence medical men are constantly questioned whether  this
 or  that article of diet is good  or bad for the stomach, while 
 154           INTERVAL BETWEEN MEALS

 curiosity rarely, if ever, extends so far as to inquire in' what
 circumstances  the one ought to be preferred to the other,
 or whether Nature  has  annezed  any other conditions  to
 sound digestion which also it may be expedient to  know
 and to observe.   In  reality, however, the choice of aliment
 is but one out of many circumstances which require  to be
 attended to ;  and it often happens that the same food which
 is digested with ease when the collateral conditions are ful-
 filled, will remain for hours on the stomach unaltered  when
 they  are neglected.   It is essential, therefore, that  these
 conditions should be known and attended to.   Even  when
 we have ascertained what kind  of food is most suitable for
 the individual,  the limes and quantities in which  it  ought
 to be taken  are still important  points to be  determined.
 However well regulated the diet maybe in other respects,
 if we eat either more or  less  frequently,,or in  larger  or
 smaller quantity, than the wants of the system require, diges-
 tion  and nutrition will speedily suffer.  It will be proper,
 therefore, to begin our inquiry by explaining the principles
 according to which the  times  of eating ought to be ar-
 ranged.
   Times of Eating.—If we look to the exposition of the
 objects  of eating already given in treating of  appetite, it
 will  be obvious that Nature intended us to regulate our
 meals by the  demands of the  system, and  not to eat  at
 stated hours as a matter of course,  whether nourishment be
 required or not.  If we are engaged in occupations which
 induce a rapid expenditure of material, or if growth is going
 on  so fast as to require  unusually ample supplies,  food
 ought to be taken both more frequently and in larger quan-
tity than when  we  are differently circumstanced ;  or,  in
other words, food ought to bear a relation to the mode of life
and circumstances of the individual, and not be determined
by a reference to time  alone.
  In  reality, however,  the  animal economy is  constituted
 with  so strong a tendency to periodical activity, that, after
 growth is completed and the waste of the system becomes in
 some  measure definite and regular, as great an approxima-
 tion as possible oujrht to be made to fixed times of eating.
 In general little difficulty and much advantage  attend the
 arrangement;  because, where the  mode of life is nearly
the same throughout a whole class, the same waste will go
on, anu^ consequently, the demand for a supply of nourish- 
TO BE DETERMINED BY CIRCUMSTANCES.      155
ment in all the individuals composing it will be felt at nearly
the same intervals, subject only to such variations as are
induced by original differences of age and constitution.  As
regards each class, therefore, regularity in the recurrence
of meals is not less natural than advantageous ; and it  is
only when we attempt to combine a given order of diet with
different  and even incompatible modes of life,  that Nature
refuses to sanction the arrangement.
  So strong, indeed, is  the tendency to periodicity in the
system, that appetite returns for a time at the  accustomed
hour, even after the mode of life, and consequently the wants
of the system, have undergone a change; and if not gratified
it again  subsides.  Ultimately, however, its call  becomes
too urgent to admit of being a second time disregarded.
  Nature has accorded  to man considerable latitude in fix-
ing the interval within which the demands of appetite must
be gratified, and in this provision has obviously had in view
the  infinite  variety of circumstances  in which he may be
placed in the discharge of his  numerous duties.   As a ge-
neral rule, and in mature age, five or six hours should elapse,
between one meal and another—longer if the  mode "of life
be indolent, shorter if very active, as during the  efferves-
cence of childhood and  youth.  Digestion  occupies from
three to  five hours, according  to the nature and abundance
of the meal and  the state of health ; and the  stomach re-
quires an interval of rest after, the process is finished, to
enable it to recover its tone, before it can again enter upon
the vigorous performance of its function.   Appetite, accord-
ingly, does not begin to show itself till some time  after the
stomach has become empty ; and if food be  taken before it
has  recovered its  tone by repose, the  secretion of gastric
juice and the contraction of its muscular fibres  will be alike
imperfect, and digestion consequently become  impaired.
If, again, food be taken before the digestion  of the preced-
ing meal be completed, the result will be still worse ; be-
cause  the whole of  the gastric juice which the  stomach
can  secrete being already engaged in the  solution of the
first meal,  the  one  subsequently taken  will necessarily
remain unsupplied, and, consequently, liable  to undergo the
same chemical change—fermentation—which would occur
in  it if exposed out  of the stomach to an equal degree  of
heat and moisture.   And, therefore, Dr.  Kitchener,  in
alluding to the advantages arising from giving  the stomach 
156       INFLUENCE OF TRAINING ON EATINO.
    an occasional rest, truly and forcibly remarks that,  " unless
    the constitution is so confoundedly debilitated  that the cir-
    culation will not run alone, abstinence is the easiest—
    cheapest—and best cure for the disorders which arise from
    indigestion or intemperance."   In these  cases,  indeed,
    abstinence is to  the exhausted stomach what  repose is to
    the wearied muscles, and hence the benefits which result
    from its judicious observance.
      The interval between each  meal ought  to be longer or
    shorter in proportion to the quantity eaten, and to the age
    and more or less active habits of the  individual; and it
    would be absurd  to fix the same standard for all.  A young
    growing  person  requires frequent supplies of  nourishing
    food  to furnish  the materials  of growth.   For a  similar
    reason a strong labouring man, whose system is subjected
    to great waste from being engaged all day in hard work,
    will  require  not only  more  frequent  but more  copious
    meals than an indolent and sedentary man  ;  and those
    who  eat very little will-require to eat at shorter intervals
    than those  whose meals are heavy.  An invalid on restrict-
    ed diet may thus require  to eat every four hours, where,
    with a more copious diet, once in six hours would  be suffi-
    cient.   Some, indeed, are so constituted as to require only
    one or two abundant meals in twenty-four hours.
       Early training exercises great power over the stomach
    as well as over the mind.   In  savage life,  where the sup-
    plies of food are precarious, a  single meal  may be copious
    enough  to  serve for two or  three days  together.  The
    monks of  La Trappe make it part of their religion to eat
    only  once a day, and nothing but vegetable food—unless
    when sick, in which case milk is allowed ; but it  is long
f   before  they become reconciled  to the restriction.   Some
    years ago  I travelled for three days in a French diligence
    with  one of the  order, then on his way from Italy to the
    Monastery  of La Trappe,  near Nantes, and observed that
    he scrupulously  adhered  to his  single  meal.    He had a
    dispensation, however, authorizing him to  eat animal food
    and use wine during his journey ; and I was  surprised at
    the extent to which  he  availed himself  of  the permission,
    by devouring at  one time a store  sufficient to last for a
    week instead of a day.  But, as in the case of the  boa
    constrictor  in similar circumstances, a  deep lethargy im-
    mediately succeeded, and it was not till four or five hours 
BEST TIME FOR BREAKFAST.
157
afterward that his almost apoplectic features became again
animated and expressive : iong before next meal, however,
his renewed appetite betrayed itself by expressive glances
toward the comforts of the breakfast-table.
   Nature, then, has fixed no particular hours for eating,
but has established principles easy  of discovery and of ap-
plication, by which, with a little reflection, we  may readily
adapt our regimen to our respective  ages, constitutions,
and habits.   According to these principles, whenever the
mode of life is uniform and the expenditure of the system
pretty equable, fixed hours for meals may  be safely adopt-
ed ;  but where these are irregular, the  intervals between
meals ought also  to vary, and the safest  guide will  then
be the recurrence of true appetite—a sure sign that the
system is in need of a supply.
   Meals, then, ought to be  early or late in proportion to
the habits of  the individual.  If, adhering to  the order of
Nature, we work by day and sleep by night, an  early break-
fast, an early dinner, and an early evening meal  will un-
doubtedly be the most conducive  to sound digestion and
the enjoyment of  health.  But if, against  the laws of Na-
ture,  we rise  from bed  late  in  the forenoon, reserve our
activity till late  in the  afternoon, and do  not  go  to  sleep
till two  or three hours before daybreak, then assuredly
the late breakfasts and dinners of  the fashionable  society
of the present day will be the  best for our comfort  that
can be devised.   Here the grand error is in the unnatural
mode of life which renders  very  late  meals necessary.
But so long as such a mode of life is persisted  in, it would
only add to its injurious effects to  attempt to combine it
with the observance of  the early hours of  eating suited to
those who live in conformity with nature.  This principle
is often lost sight of by medical men.
  The proper time for taking breakfast ought  to be regu-
lated  by the  individual constitution and  habits.   Those
who eat  supper ought not to breakfast till one or two hours
at least after  rising ; but persons  who dine late  and eat
nothing afterward, and whose digestion is vigorous, require
breakfast sooner.   Individuals of a delicate frame are often
unable for either bodily or mental exertion  in the morning,
and are invariably injured by any attempt at active exercise
or serious thinking before breakfast;  but strong  healthy
persons,  and  invalids  in whom  digestion is  slow rather 
 158  SUSCEPTIBILITY GREATEST BEFORE BREAKFAST.

 than diseased,  may enjoy, and  even be benefited by, two
 or  three hours of activity before their morning meal, es-
 pecially if accustomed  to eat supper.  Keeping the phy-
 siological principle in view, a little  experience will enable
 any one to decide what time is the most suitable for himself.
 As a general rule, perhaps, breakfast about half an hour
 or an hour after rising will be found most beneficial; but
 those who rise  very early will do well to follow the French
 custom  of taking  a  cup of coffee  or tea,  and  bread, on
 getting up. and  reserve their appetite for a more substantial
 breakfast  three hours later.   This is an invaluable rule for
 students,  who often  seriously impair their  digestive func-
 tions by studying for hours in the morning, regardless of
 the craving of the system for nourishment and support.
  If exposure of any kind is to be  incurred in the morn-
 ing, whether to the weather or to the causes of disease, it
 becomes a matter of much importance that breakfast or
 some substitute for  it should be taken previously.  It is
 well known that the system is more susceptible of infec-
 tion, and of the influence of cold, miasma, and other mor-
 bid causes, in the morning  before eating than at  any other
 time ; and hence it has become a  point of duty with all
 naval and military commanders, especially in bad climates,
 always to give  their men breakfast  before  exposing them
 to morning dews or other noxious influences. - Sir  George
 Ballingall even  mentions a regiment quartered in  New-
castle, in  which typhus fever was  very prevalent, and in
which, of all the means  used to check its progress, nothing
proved so successful as an early breakfast of warm coffee.
In aguish countries,  also, experience has shown that the
proportion of sick among  those  who ate  exposed  to the
open air before getting anything to eat, is infinitely greater
than among those who have been fortified  by  a  comforta-
ble  breakfast.   Where  there is any delicacy of constitu-
tion, the risk is of course increased.
  The cause of this susceptibility in the  morning is not
difficult  to he discovered.   It arises from  the craving ac-
 tivity of the absorbents excited by the wants of the system,
 and the  length of time which has elapsed since the preced-
 ing supply.   If we suppose the previous  meal to have
 taken place  at  six o'clock in the evening,  the process of
 nutrition,  the  various secretions, and the  exhalation of
 waste matter from the lungs, kidneys, and skin, must have 
        ABSORPTION MOST ACTIVE IN THE MORNING.    159

been carried on for the twelve to fifteen hours between that
time and the usual  hour of breakfast upon the nourishment
taken in during the preceding day.  The result is, that the
stomach, duodenum, and upper intestine, from which chiefly
fresh  nutriment is obtained, have been for some  time en-
tirely  empty, and are, consequently, without any means of
supplying the loss which the system has sustained  during
the night.  In these  circumstances, if food be taken, the
absorbents, refreshed by repose and  stimulated by want,
act vigorously, and imbibe the chyle as fast as it is formed.
But if legitimate food be denied to them, the same  prone-
ness to energetic action will impel them to imbibe  any
morbid  or  other  agent which may be  presented  to them.
When the  system is fully replenished, on  the other hand,
the natural stimulus of the  absorbents is withdrawn,  and,
consequently, noxious effluvia,  even when present  in  the
air, are less likely to  be imbibed than under opposite cir-
cumstances.  It is from this constant  relation between the
wants of the system  and the state of the absorbents  that
our first daily meal is almost universally of a  more  fluid
and less substantial description  than any of the  subsequent
ones,  an the great  loss of fluid by exhalation  during  the
night  causes a natural demand for liquids in the morning;
while our active exertion and loss of solids during the day
create a proportionate demand for a more substantial repast
in the afternoon.
   The function of absorption, then, is  at  its highest pitch
of activity in the morning, simply because every part of the
frame is craving  for a supply to  repair the losses which it
has sustained ;  and if the  body  be exposed to miasma or
other impurities, they will be much more easily and speedily
absorbed by the  skin, the  pulmonary membrane, and the
stomach, before eating, than after the absorbents have been
supplied with their  legitimate  food.   This is  the  true
theory of the greater susceptibility of infection and other
poisonous influences when  the stomach is empty.
   So rapid is absorption  from the stomach in the  morning,
that 1 have repeatedly seen nine tumblers of a saline  mi-
neral water taken at eight o'clock, and a very hearty break-
fast finished within  half an  hour after the water was drunk !
When  in  bad health a few years ago, I  observed  almost
equal expedition  in my own person.   I took half  a pint of
ass's  milk  at seven o'clock, and, in consequence of cough- 
 160  DELICATE PERSONS SHOULD BREAKFAST EARL*.

 ing  violently, was  frequently seized with  vomiting and
 retching within twenty minutes  after taking it;  but only
 twice or thrice was any portion of the milk perceptible, al-
 though  the stomach was entirely emptied.  This was even
 more remarkable than  the other case, inasmuch as milk
 undergoes digestion, which vteter does not.  In allusion to
 this rapidity of absorption, Sir Francis Head, in speaking of
 the quantity of the chalybeate waters swallowed of a morn-
 ing at the Brunnens of  Nassau,  humorously remarks, that
 "one would think that this deluge of cold water would leave
 little room for tea  and  sugar;  but, miraculous as it may
 sound, by the time I got to my ' Hof there was  as much
 stowage in  the vessel as when she sailed: besides  this,
 the  steel created an  appetite which was very  difficult  to
 govern."*
   In setting out early  to travel, a  light  breakfast before
 starting is a great protection against colds and subsequent
 fatigue  or exhaustion.   I am quite  aware that robust and
 healthy men can  and do take much active exercise before
 breakfast with apparent impunity, if not  benefit, and I have
 often done so myself; but experience ultimately taught me
 that I became sooner exhausted on continuing the exertion
 through  the  day, than  when  I  began  by eating a little.
 During the first winter of my studies in Paris, I  regularly
 attended the surgical visits at the Hotel  Dieu, which began
 at six o'clock in  the  morning  and  lasted tiff nine or fre-
 quently half-past nine.   Not being then aware of the prin-
 ciple under discussion, I  ate nothing till my return  home ;
but I felt more weariness before the day was done  than
the mere exertion ought  to have produced.  At last, on
noticing for a time  the regularity with which many of the
work-people  passing along paid their respects at a small
 Bhop, the only one then open, where fancy rolls were sold,
 along with wine and brandy, I thought  of following their
 example  to the extent of trying how far  a roll would add
 to my comfort.  I soon found great reason to be pleased
with the expedient; and discovered that I was  not  only
less  exhausted during the day, but more able to follow the
lecture which concluded the visit, and in possession of a
 keener appetite for breakfast at my return ; and ever since
 I have  acted on the  principle now inculcated, and with
 marked benefit.   I was then  astonished  at  the regularity
           * Bubbles from the Brunnens of Nassau 
      EXPOSURE MOST HURTFUL BEFORE BREAKFAST.   161

with which  the  Parisian workmen  seemed to take their
morning allowance of brandy on  their way to their labours,
apparently for the very purpose of getting that wholesome
energy which they ought to have sought in food alone.
  During the prevalence of cholera both here and on  the
continent, it was often remarked that a large proportion  of
the attacks  occurred in the  morning, in persons who had
gone to bed  apparently well.   Chronic invalids and persons
of a delicate habit of body are also familiar with the fact
of the animal heat and  general vigour diminishing toward
morning.  When reduced in strength by pulmonary com-
plaints, I often passed  the night in comparative comfort,
sure to awake about four  or five o'clock with a feeling of
chill and absence of animal  heat, which I could not dissi-
pate till after receiving  sustenance.
  From these facts, the general inference is clearly war-
ranffd, that delicate persons ought to have some kind of
food soon after rising, and that even those who are robust
will act wisely in not exposing themselves unnecessarily to
fatigue, infection, or other morbid  causes, without having
previously  supplied  the wants of the system, either par-
tially by a cup of coffee, tea, or milk, or entirely by a regu-
lar  breakfast.  Where  fever, for example, is  in a family,
the danger  of infection will  be  much greater to a person
going directly from his own bed to  the bed-side of the  pa-
tient, than to one who first takes  the precaution of drinking
were it only a cup of coffee.   I have elsewhere noticed  the
safety which Captain Murray obtained for his crew in  the
West Indies, partly by attention to  this rule;  and  have
likewise referred to the  experience of Sir George Ballingall
in the prevention of fever by a similar expedient.
   In  boarding-schools  for the  young  and growing, who  '
require plenty of sustenance and are often obliged to rise
early, an early breakfast  is almost  an  indispensable con-
dition of health.   On the continent, in similar  establish-
ments, seven o'clock is the  common hour for breakfast,
especially in summer.
   In recommending what I conceive ought to be the general
rule, let me not be understood as wishing to  extend  it so
far as to advise  those whose constitutions admit of two or
three hours'  activity  before breakfast,  to abandon what
experience  proves to be beneficial to them.  My only wish
is, to help those who are  in doubt as to choosing the plan 
162             BEST TIME FOR DINNER.
 which is most likely to be of advantage, and to relieve those
 who are already suffering from ignorance.
   The morning meal being comparatively a light one, and
 the stomach being then in high vigour, digestion  goes on
 briskly, so that appetite revives within a shorter time than
 after  the more substantial dinner.   Accordingly, in all na-
 tions  and classes of  society not perverted from  the course
 of nature, a longer interval than five  hours rarely elapses
 between breakfast and dinner.  Our  forefathers  dined  at
 noon, as  our sailors continue to do  at  the  present day.
 Over  no small portion of the continent of Europe the same
 primitive hour is still adhered to ; and among the labouring
 population of Great Britain one or two o'clock is the com-
 mon  dinner-hour, eight  or nine being that of breakfast.
 Even  the rich  manufacturers of Manchester  and other
 English towns continue to this day to  dine at one  o'clock ;
 and the very universality of  a mid-day meal among those
 who  rise  early,  is itself a strong presumption in favour  of
 its propriety, and of its being in harmony with the laws  of
 the animal economy.
   To prevent business from interfering unduly with diges-
 tion,  it was formerly the custom in  Edinburgh to shut  up
 shops and counting-houses for two  hours in the middle  of
 the day ;  and in Switzerland I have  seen  the same practice
 followed.  The members of the family being then assembled,
 relaxation and enjoyment take the place of the cares of the
 world ;  and the result is highly satisfactory.  The appetite
 is keen enough to induce them to eat with zest all that Na-
 ture requires, while it wants  the resistless force which  is
given  by a fast of eight or nine  hours.  There is, conse-
quently, slower  mastication, less  cramming,  and a  much
earlier return of the aptitude for business ;  while at the same
time the mental  and bodily faculties are  refreshed  by the
interruption of their accustomed  labour, and the affections
cherished  by  healthful  domestic  intercourse  taking  place
before too much weariness is induced to permit of its being
enjoyed.   In  England  such weariness is a very common
occurrence.   The parent and husband, exhausted by the
eager  pursuit of wealth during the  livelong day, returns
home  in the evening  jaded and harassed,  and little able  to
 take pleasure or interest in the enjoyments of his wife and
family.  Hence, indeed,  too  often  arise  indifference and
 unhappiness between those whom Nature has formed as  if
on purpose to suit each other. 
BEST TIME FOR DINNER.
163
  In  enterprising commercial communities—in London
and Liverpool, for example—it is a common practice  to
hasten away to the counting-room immediately after an early
breakfast;  to remain there in active employment from nine
or ten  o'clock in the morning till six o'clock in the evening,
and then to hurry home to  a late dinner at six or seven
o'clock ;  by which time the vital functions have become  so
far exhausted as to create a  strong desire for indulgence in
something stimulating both in food and drink.   If this desire
be gratified, immediate relief will be obtained, and a tempo-
rary feeling of comfort pervade the frame; but nothing can be
more erroneous than to regard this as a proof of the indul-
gence being beneficial.   The organization soon gets  accus-
tomed to the stimulus ; its susceptibility becomes impaired
by the  frequency with which  the latter is administered ; and
in a short time indigestion is the inevitable consequence.
  The evils attendant on this course of life  are not unfre-
quently aggravated by the preposterous means resorted to
for their prevention.   Having some  vague notion that ex-
ercise  improves digestion, and not being at all aware that
there is an improper as well as a proper  time for taking it,
many persons, after being exhausted by seven or eight hours'
confinement to the counting-house, proceed  to take  a walk
of four or five miles  before going home to dinner, and thus
utterly throw away the little strength that was left to them,
and are filled with disappointment on finding their appetite
and digestion worse than before.*  Dr. Paris mentions the
case of a clerk in a public office who brought upon himself
all the horrors of dyspepsia and  melancholy by following
this plan.  He breakfasted at nine, went to his office at ten,
continued there till five, walked till seven, and then dined.
He was  cured in six  weeks, by  adopting a more rational
regimen and dining at three, o'clock.
   Many females and  delicate persons injure their powers of
digestion by delaying  their exercise till  the system is too
much  exhausted  to profit by it.  In boarding-schools, from
the desire which  is felt to have all the lessons over before
allowing any play, the same error is often committed, and
with pernicious effects on the health of the pupils.
   As  a general rule,  then, not more  than five hours ought
to intervene between breakfast and dinner.  If the mode
  * Respecting the  proper regulation of exercise, see The Princi-
ples of Physiology, 10th edition, chapter vi. 
164
BEST TIME FOR DINNER.
 of life be such as involves great activity in the open air, or
 the period of life be one of rapid growth or filling up, (as
 during youth  or convalescence  from  illness,) the  interval
 may with propriety be shortened ; whereas, if the mode of
 life be sedentary, and unattended  wiih  much  activity of
 nutrition, the  interval may be ci>n-id"r»bly protracted with-
 out much inconvenience.   Much also ought  to depend on
 the natural rapidity or slowness of  digestion.   In some
 constitutions ehylification gojs on so  slowly that  the  indi-
 vidual can pass with ease eitjht or ten hours without food  ;
 whereas, in others it is so rapid that a fresh supply becomes
 necessary in half the  time.   Spnllanzani himself was an
 example of  the former kind ; for in him digestion  went on
 so slowly that he was unable for study till five or  six,hours
 after even a very spare dinner   The proper  rule  in every
 case is, to take  dinner at such  an  interval after  breakfast
 as the return of healthy appetite indicates,  whether  that
 interval be longer or shorter than the average specified.
   That,  according to this rule, the  general time for dinner
 ought to be somewhere about five  hours  after an ordinary
 breakfast, is evident from the almost universal  return of
 appetite  at the end of such an  interval,  and from the fact
 that  many,  through sheer  inability  to resist  longer the
 wholesome  cravings of nature,  are in the regular practice
 of eating dinner at that time,  but,  to save appearances,
 give  it the name of luncheon;  by which means they hold
 themselves entitled to the enjoyment of a second and  more
 substantial dinner later in the day.
   Invalids,  dyspeptics, and  all  who, possessing  vigorous
digestion, wish to  retain it,  will do well  to  follow the in-
 tentions  of  Nature,  and observe the intervals which she
has appointed.   Those who  disregard them, and still digest
without difficulty, have reason to be grateful to Providence  ;
but they may  rest assured that they will longer enjoy (heir
privilege, and better evince their gratitude,  by regulating
their conduct according to the ordinary laws  of the animal
 economy, than by presuming too much on their  supposed
 exemption from trie bad  consequences of  their  habitual
 infringement.
   Supposing nine o'clock to be  the hour of breakfast, the
 natural dinner-hour would thus be two o'clock ;  and such,
 accordingly, is that sanctioned by the most  extended ex-
 perience, and  which ought to  be adhered to by all whose 
BEST TIME FOR DINNER.
165
occupations will admit of its observance, and who wish to
enjoy the highest health of which they  are susceptible.
  Artificially arranged, however, as society now is, whole
classes of the community,  from business and other causes,
find it impossible to dine till much later in the day.  The
question then comes to be—As we cannot implicitly follow
the system  laid down by Nature, what is the nearest approxi-
mation which we can make to it 1   Ought we to eat nothing
till we can  find time to dine at five, six, or seven o'clock;
or ought we rather to take a light luncheon  at the natural
time, about one or two o'clock, and delay  eating a more
substantial  meal till the later hour at which alone we can
find leisure to digest it 1
  From the exposition already given, the reader will have no
difficulty in determining that the latter is the preferable plan.
If we leave the stomach too long empty,, its powers, as well
as those of the system at large, are liable to become impair-
ed from exhaustion;  ahd, therefore, when  dinner cannot
be taken earlier than seven or eight hours after breakfast,
most people  will find  it advantageous  to partake of some
slight refreshment in the meantime—enough to blunt the
keenness of appetite, but not entirely to destroy it.  When
the  individual  is exposed to much bodily exertion in the
open air, or is at the  period of rapid growth, a  portion of
animal food, or an ordinary luncheon, taken  in moderation,
may be allowable, and even requisite ; but where the habits
are sedentary and the constitution formed, a bit of bread or
biscuit, and a glass of water, will be far more serviceable.
Many people, from want  of any better occupation, make
a pastime  of filling their  stomachs every forenoon at the
pastry-cook's, with as little regard to its powers and neces-
sities as if digestion  were meant merely as an  appendage
to  taste ;  and think  themselves  entitled  to complain of
their defective appetites, and the great discomfort which
attends the subsequent indigestion of a heavy dinner.   To
relieve the weakness, arising not from  exhaustion but from
the oppression of satiety, they resort to  wine, as if by adding
 fuel to the fire they could hope to extinguish the flame !
   Even in fashionable life  the  superiority of Nature's ar-
 rangements over those of man is so far acknowledged, that
 it is an almost universal  rule for children to dine  in  the
 middle of the day ; and  there cannot be a doubt that the
 practice is attended with manifold advantages to the young, 
166
BEST TIME FOR DINNER.
 although, as  regards their moral training, these would be
 greatly increased were they to associate at meals with their
 parenis,  instead of  being left entirely to the company  and
 management of servants.
   Here I cannot refrain from earnestly soliciting the atten-
 tion of the reader to the injury inflicted on the young by the
 irrational mode of life and education to which they are now
 subjected.   As growth  and nutrition are  in them in their
 highest activity, it follows that at no period of life  is strict
 adherence to the laws of the animal economy of  so much
 moment, because, if the youthful system does not receive
 at the proper intervals the supplies of food of which it stands
 urgently  in need, it must necessarily be  impaired  in tone,
 and  become  more  liable to the inroads of disease.   The
 completed and compact frame of an adult may  resist for a
 time delay or irregularity in its  supplies, but the undeve-
 loped and susceptible organization of the young suffers from
 the very  first, and the evil increases  in proportion as the
 aberration from  the order of Nature  is repeated.   Hence
 reason, affection, and enlightened benevolence all concur
 in enforcing a strict adherence to an  early dinner-hour for
 the young.   On no account whatever ought it to be delayed
 beyond one or two  o'clock.   And yet, if  we examine the
 customs  of  society, especially  in  the middle and higher
 ranks resident in towns,  we find the school occupations so
 irrationally arranged, that, while the children are obliged to
 breakfast early, even in winter, to reach them in time, most
 of them find it impossible to dine till five  or six o'clock—
 eight or nine  hours  after  their first meal, instead of four or
five.  And when stunted growth, feeble digestion, delicacy,
or bad health results as the natural consequence of exhaus-
tion, instead of ascribing it  to its true  cause—the depri-
vation  of sustenance—and  trying  to cure it by a better
regulation of  the diet, it is usual to leave the evil  to do its
worst, and to content ourselves with complacently lamenting
the degeneracy of the age, and  boasting of the  marvellous
constitutions  and hardihood of  the children of our day,
whom neither wind nor weather could hurt.  If it were a
 favourite  colt or dog whose training we were  superintend-
 ing, the folly  of  shutting it  up all day in a confined atmo-
 sphere, and denying it food at proper intervals, would stare
 us in the  face.  But, in our vain conceit, we act as if degra-
 dation were implied in the admission that in man health and 
                BEST TIME FOR DINNER.             167

growth are regulated by the same physiological laws as in
animals, and as if we  were better pleased that disease and
death should follow than that we should study and obey the
laws which God himself has appointed for our guidance.
  The evil,  however, is the source  of much suffering and
disappointment; and  as it cannot be corrected until  the
public is rendered fully aware of its existence and influence,
it cannot  be too often brought under its notice, or  too
strongly condemned.   The teacher alone has not the power
of providing a remedy.  The concurrence and co-operation
of the parent are indispensable ; but both combined could
easily effect such a distribution of the time and business
of the  school, as to leave  at least a couple  of hours in the
middle of  the day appropriated to dinner and play after it in
the open air.  It is no valid objection to say that in winter
the day is too short  to allow the " sacrifice " of so much
time.  The shorter it is,  the greater is  the  necessity for
making the most of it by adequate attention to the laws of
health.  The real " sacrifice " of time is when health is im-
paired and progress retarded by undue confinement and depri-
vation  of exercise in the open air.   The very shortness  of
the day, indeed, implies that we should employ the hours of
darkness in in-door occupations, and make  the most of the
daylight' by going  out while we have  it;  and I have  no
doubt that, as society advances, this truth  will be felt and
acted upon to the great advantage and delight of the young.
  An additional, and with right thinking people an irresis-
tible, reason for reforming  this  error in education is, that,
while it injures the physical system, and in delicate consti-
tutions seriously affects the health, it is scarcely less hurt-
ful to the mind, for which the sacrifice is made.  Experience
bas shown that the excessive cultivation of the intellectual
faculties in the young to  the disregard of  the laws of the
physical organization, is productive  of  evil even to the in-
tellect.   When schooling  and tasks are continued daily for
many successive hours, the attention flags and the vigour of
the mind becomes impaired instead of being increased.   In
this w iy the progress made is in the long run much smaller,
and acquired at  a much greater risk of health and life, than
when  appropriate  intervals are  allowed, not only for eat-
ing  meals at the times required by the wants of the  sys-
tem, but also for the enjoyment of adequate muscular exer-
cise in the, open  air.  In  some schools,  where a  more 
163
BEST TIME FOR DINNER.
 rational system has been tried, where  the confinement  to
 school has been lessened by one-half, and the time for meals
 and exercise has been doubled,  as  well  as  arranged on
 sound physiological principles,  the results have been not
 only improved health and  increased  physical activity, but
 also more rapid intellectual progress and a more perfect
 developement of mental vigour.   In the one case  the mind
 is exhausted by the  continued and monotonous strain upon
 the attention, and  the body from want of exercise, food, and
 pure air.   In the other the mind is strengthened by strong
 calls which rouse  and agreeably stimulate attention,  while
 the body  also gains  in vigour from receiving  nourishment
 at the right time,  and obtaining that  muscular exercise  in
 the open air without which health cannot long be preserved.*
   Supposing it to  be made an imperative condition of .our
 social existence that we shall rise after mid-day, and not go
 to bed till a late hour in the morning, the present fashion
 of dining at seven or eight o'clock  becomes much  more
 rational than is commonly imagined by those who declaim
 against it without regard to the concomitant circumstances.
 It is, no doubt, most absurd and hurtful for a man who rises
 at seven or eight  o'clock, breakfasts  at nine, and goes to
 bed at  eleven, to delay dining till seven in the evening  ; but
 it by no means follows  that seven is a bad dinner-hour for
 a person who rises at twelve or one o'clock, breakfasts at
 two, and goes to bed at three in the morning.   The inter-
 val between the breakfast at one and dinner at seven o'clock
 is the same as between breakfast at nine and dinner at three,
 namely, six hours—which is little more than enough.  The
 error lies not in the hours chosen for meals, but in the  utter
perversion of the whole system oj living, by which night is
converted into day, and the business of life is  postponed
five or  six hours beyond the time appointed by the Creator
for its performance.  So far from the late dinner being hurt-
ful in such circumstances, it would be perfectly proper if the
mode of life which  leads to it were itself imperative.  Under
the present perverted system, accordingly, it is only the sti-
 mulus and support  which the late dinner affords that enable
 the victims to withstand the fatigue even for a single week.
  No one has a stronger sense of the injury done to society
 by the  wide departure from the laws of Nature by which its
  * The reader will find this subject more fully discussed in the
 tenth edition of The Principles of Physiology, &c. 
                 BEST TIME FOR DINNER.             169

present arrangements are characterized, and no one is more
anxious to contribute all that is within his power to reform
them, than the writer of these  pages ; but,  in returning to
the order of Nature, the whole mode of life must be amend-
ed and brought into harmony with the laws of the animal
economy ; and no real  progress will  be made  by merely
altering the horir of dinner, while the conditions which have
led to the existing arrangement are left unchanged.
  In the country, even among the higher classes, a greater
approximation to the order of Nature is observable than in
towns.  The inducements to sleep away the day and to be
awake during the night are diminished ; bodily exercise and
exposure to the open air are more indulged in ;  the appe-
tite becomes keener and digestion more  vigorous ; and, as
a necessary result, meals are taken an hour or_two earlier.
But, throughout all  these changes, the  general feature of
having some kind of refreshment, either luncheon or dinner,
within four, five, or six hours after breakfast, may be pretty
accurately traced.
   If business admits of it, and the person  can  then com-
mand two hours of relaxation, the best plan, unquestionably,
is to dine about five  or six  hours after breakfast.  But if
this be impossible, and an active exertion of mind or body
must  be continued for several hours longer, it  will be far
better to eat some light refreshment in the forenoon, and to
postpone dinner, not  only till business is over, but till half
an hour or an hour's repose has allowed its attendant excite-
ment or fatigue to subside.  By this means the stomach will
enter upon its duties with vigour, and the dinner be digested
with greater comfort and despatch than if  we sit down to
table  the moment our work is finished.   In this way the
tedious quarter of an hour preceding the announcement of
" dinner " is far from being lost to the subsequent digestion.
   Very few people, indeed, can eat a good dinner and return
immediately to bodily or intellectual labour with continued
impunity.  On  this  account,  actors,  for example,  whose
vocation requires exertion of  both mind and  body, almost
all either dine very early, or take their chief meal at night
on their  return  home, the latter being  the more common
practice.  Students, literary men, and persons intently en-
gaged in business, are very apt to damage themselves by
neglecting relaxation at and after meals.
   The time for dinner ought, then, to vary according to
                           15 
170
USES OF TEA AND COFFEE.
the constitution, occupations, and mode of life of the indi-
vidual ; and the nearer the whole of these can be made to
approximate to the intentions of Nature, the  more vigorous
will be the powers  of digestion, and  the more complete
the nutrition of the body ;  and,  consequently,  the  more
easily will the stomach recover the tone which it may have
lost from previous mismanagement.  In attempting to cure
indigestion, notwithstanding the most scrupulous adherence
to the rules given for the proper selection of  food, if we set
at defiance all the other conditions of healthy digestion, our
adherence will be of little avail.   Whereas,  if we fulfil the
laws of our constitution, by rising from bed in the morning,
obtaining a healthy appetite  ana  lively circulation by the
regular exercise of the various functions of mind and body
in a free and pure atmosphere, eating moderately, and en-
joying social relaxation after our meals, digestion will be
so far  strengthened  that no very rigid observance of  any
particular kind of diet will be necessary ; it being always
understood, however, that we shall not exceed in quantity
what the wants of the system require.
   It would be a waste of time to discuss gravely whether tea
and coffee ought to be allowed in the evening.  Custom has
already decided the point, and experience has shown that,
in moderation,  they rather promote than impede  digestion.
But when strong and taken in quantity,'especially by persons
of a sanguine or nervous constitution and weak  digestion,
they are decidedly hurtful.   Many ruin their health and in-
duce severe nervous depression from the  abuse of strong
green  tea, at the very time when they profess to know no
cause to which their misery can be ascribed.  Literary men,
artists, and actors, and  other public performers who  are
subjected at times to great intellectual or moral excitement,
also suffer very frequently from the abuse of tea  or coffee.
When the dinner is early—say at one, two, or three o'clock
—a light meal of tea and  bread in the  evening is very
suitable, as it saves the necessity of eating a heavier sup-
per.  If the individual be accustomed to much active exer-
tion in the afternoon, so as to cause considerable waste in
the system,  and especially if  he be young, a  small addition
of animal  food  may be made with  great propriety to  the
evening meal.  But. on the other  hand, when the dinner is
late, or little exertion is incuned after it, tea or coffee ought
to be used more as a diluent than as a meal. 
        PROPRIETY OF- A THIRD MEAL CONSIDERED.    171

   The French drink a  single cup of strong coffee without
cream immediately after dinner, and find digestion go on
all the better for it.  It acts as a strong stimulant, and cer-
tainly increases the feeling of comfort  for the time.   Like
all other stimulants, however, its use is attended with the
disadvantage of exhausting the sensibility of the part on
which it acts, and inducing weakness.   This inconvenience
is not felt to the same  extent, indeed,  after coffee as after
spirits, but still  it exists ; and it is infinitely better that
the stomach  should be brought up to do its own work un-
grudgingly, than  taught  to  dppend upon assistance from
without; and, therefore, such assistance ought to be reserv-
ed for the  relief of occasional exhaustion, instead of being
resorted to as a regular indulgence.   The French partake
of a much greater variety of dishes at one meal than we
are  accustomed to do, and  may thus require  the  aid  of
coffee to keep the stomach from actual rebellion.  But the
proper  way to obviate  this necessity, is  obviously to eat a
more simple and moderate meal.
   In determining whether a third meal ought to be taken,
either as tea or as supper, the general  principle already laid
down will be very useful.  If dinner  be sufficiently early
to admit of digestion being completed and of the stomach
being afterward recruited  by repose,  and if the mode of
life be active, so as to  occasion a natural return of appetite
before the day is done, the propriety of a third meal cannot
be questioned.  But if dinner be late, and  there  be too
short an interval between it and bed-time to admit of diges-
tion  being finished and the appetite renewed,  then every
additional  mouthful swallowed is sure to do mischief.  The
farmer who dines at two o'clock, for example, and, after
walking about his fields for three or four hours in the after-
noon, comes home in the evening with a genuine and un-
deniable  appetite, has a  legitimate right to an additional
 supply of  wholesome  food  before betaking himself to  his
 couch ; because a sufficient interval has elapsed to allow
 the stomach to recover itself from the labour of digesting
 his dinner, and  the continued waste of the system requires
 to be replaced.   In like  manner, the  man of fashion who
 dines at seven o'clock, and frequents  assemblies till threo
 or four in the morning,  is well  entitled to some kind of
 supper about one or  two o'clock, and  could scarcely  get
 through his laborious duties without farther sustenance from 
m
TIME FOR  MEALS.
 either food or wine, or both.   Even in his case  six hours
 may thus intervene between dinner and supper ;  and we
 know that, on an average, the digestion of a moderate meal
 is finished in four or five hours.   The chief difference be-
 tween him and fhe farmer is, that the farmer reaps health
 and sound digestion from adhering in his hours to the insti-
 tutions of the Creator, and that the man of fashion impairs
 his constitution and  enfeebles his  digestion—less by the
 improper  intervals at which he  eats, than by his wide de-
 parture from the order of Nature in the perverse mode of
 life which he adopts.
   If, following the  precepts of ultra-temperance,  we dine
 early, live actively, and go to bed with the stomach entirely
 empty, we may sleep, but our dreams will scarcely be more
 pleasant,  or our sleep more tranquil, than if the stomach
 were  overloaded.   A gnawing sense of vacuity is felt in
 such  circumstances,  which is apt to induce restlessness,
 and nervous impatience and irritability.   I have repeatedly
 seen these unpleasant symptoms dispelled, and sound sleep
 obtained,  by no other prescription than a cupful of arrow-
 root an hour or two  before bed-time.
   Where tea is made to constitute a meal,  supper is  alto-
 gether superfluous,  except in early life, and  in the  case of
 those who lead a very laborious existence and observe very
 early  hours.   In youth waste, growth, and nutrition  are
 so  active,- that a moderate supper is often  indispensable,
 especially when the muscular system is freely exercised in
 the open  air.  But it ought to be of a  light  nature, and
 taken at least an hour or two before going to bed.  If din-
 ner be taken early, and tea be used in the  afternoon, not
 as a meal, but merely as a diluent,  a light supper will  be
very proper.
  In short, the grand rule in  fixing the  number and  pe-
 riods of our  meals is, to proportion them to  the real wants
 of the system, as modified by age, sex, health, and manner
 of life, and  as indicated by the true returns of appetite;
 and, as an approximative guide, to bear in mind that, under
 ordinary circumstances of activity and health, three, four,
 or five hours are required for the  digestion of a full meal,
 and one or two hours more of repose before the stomach
can again become fit for the resumption of its labours.    If
 the meal be  temperate and the mode of life natural, diges-
 tion will be  completed  in from  three to four hours, and 
TIME FOR MEALS.
I?3
one hour  of rest will  serve to restore  its tone ; but  if
the quantity of  food be  great, or the general habit3 be
those of indolence,  digestion may be protracted to five or
six hours, and two  or more be  required  for subsequent
repose.   It  is, therefore, utterly absurd  and inconsistent
with the laws  of Natnte  to pretend, as many writers have
done, to lay down rules which  shall apply to every indivi-
dual and to every variety of circumstances.  As already
mentioned, rules  applicable  to  classes may be prescribed,
because there is a considerable similarity  in the circum-
stances  of all the individuals comprehended in each  ; but
even there numerous exceptions must occur, which can be
judged  only by the  standard of the individual constitution.
   The  Creator,  indeed, has obviously never intended that
we should be bound  down  to  the  rigid observance  of a
very strict order in  diet ;  but, to fit us for the  ever-vary-
ing circumstances in which we  are placed, has wisely and
benevolently allowed  us  considerable latitude, and  made
appetite to  vary in  the extent  and  earnestness of its de-
mands in proportion to  the  waste  to  which we  are sub-
jected for the  time.   It is astonishing how rapidly a healthy
frame accommodates itself  even to great changes  when
temperance is duly observed, and a proper regard is paid
to the intimations of appetite.
   In  suiting my own  mode  of life to the  circumstances
under which I have at various  times  been  placed, I have
repeatedly, even as  an  invalid, made sudden changes  in the
hours of eating, with no  farther injury than temporary dis-
comfort ;  but, then, I always adhered to  the general prin-
ciples above insisted on.   It was by some of these experi-
ments that my attention was first drawn to the great  influ-
ence of the"accessory conditions in retarding or promoting
digestion.   At one  time, on altering my place of residence
from Aix  to Marseilles, I changed at once  from breakfast-
mo- at eight o'clock, dining  at  two, and  taking tea in the
evening, to  breakfasting at eleven and dining at six.   For
the first few days I felt uncomfortable  from waiting so long
in the morning; but, by following the plan of taking  a cup
of coffee  and  a crust  of bread  soon  after  risit.g, and at-
tempting  no considerable bodily exertion till after break-
fast, every feeling of inconvenience ceased, and the system
completely  adapted itself to the change.   Three months
afterward  I embarked on  the Mediterranean, and  again
                           15* 
174     PRINCIPLES ON WHICH THE NUMBER AND
 passed  at once  to breakfasting between seven and eight
 o'clock, dining about noon, and taking tea in the evening,
 which I continued to do for  some time  after arriving in
 Italy.  On my way home the hours of eating were never
 two days the same, and yet I did  not suffer.  If breakfast
 was early, I ate it with relish.   If it was late, I had  re-
 course to a biscuit  or some dried fruit early in the  morn-
 ing, to sustain the system in the meantime, and was ready
 for it when it came.  In the  same way, if dinner was  to-
 day at one o'clock,  I took it when it was offered, and had
 recourse to some refreshment in the evening ;  if to-morrow
 it was postponed till eight o'clock, which sometimes hap-
 pened, the refreshment came in the forenoon, and a mode-
 rate meal was taken in the evening.
   In these changes, however, it will be remarked, that  the
 laws of digestion were, in reality, much less infringed as to
 time than one  might imagine from  merely hearing that I
 dined one day at noon and the next day at eight  o'clock
 in the evening.   At whatever  hour  the meal was taken,
 the real, wants of the system  were supplied when they
 manifested themselves in the form of appetite, and the  re-
 quisite intervals were observed.   If a substantial breakfast
 was taken at eight  o'clock, then  a corresponding interval
 elapsed before another meal followed at one or two.   If,
 again, the morning allowance was  trifling, then the real
breakfast  followed  at  an interval correspondingly short,
namely, at eleven o'clock.   So also with dinner.   And if
dinner was at one o'clock, tea followed at the distance  of
six or  seven hours ;  whereas,  if dinner came at six  or
seven o'clock,  a refreshment preceded and nothing follow-
ed it, and the  results were comfort and sound digestion.
If, however, we yield unguardedly to the impulse of appe-
tite in travelling, and eat and drink plentifully instead  of
temperately, no arrangement of hours  that we can make
will render our situation either pleasant or healthful.
  While, therefore, it seems to be  obvious beyond a doubt,
that those who live according to the laws of Nature and
begin their activity with  the morning, should  breakfast
betimes, dine early in the day, and take a  lighter meal  in
 the evening, and that those who do so  will reap a reward
 in health and vigour of mind and body unattainable to the
 same extent by  those  who live differently, and convert
 night into day—it would be not less hurtful than absurd 
TIME OF MEALS OUGHT TO BE DETERMINED.     175
tu prescribe the same  hours for meals to all, whatever
their periods of activity and whatever their modes of life;
and  I cannot help thinking, that it is the preposterous at-
tempt to generalize too much which, losing sight of true"
principle and the modifications whicn it requires in indivi-
dual cases, ha-s brought dietetic precepts into disrepute, and
led to the belief that the  rules laid down are merely  arbi-
trary assumptions, resting  on no solid foundation in the
human constitution, or in the designs of our Creator.
  As experience is the best guide  to knowledge, I  may
be allowed to add,  that, when travelling on the continent
in health  and strength, I suffered more from  feverish fa-
tigue and  stomachic discomfort, induced  by ignorant in-
fringement of the laws of digestion,  than I ever afterward
did,  even  from more  continued exertion when travelling
as an invalid under a better  regulated system  of  diet.   I
did  not, in  either case, make any exception to the meals
which awaited our  arrival at the inns, or to the hours at
which they were served.  The chief difference was, that,
when well, I ate till my appetite was fully satisfied, under
the  notion  that,  in travelling, a  full diet is necessary to
enable  one to withstand the fatigue ;  and that, as an in-
valid, on the other hand, I  ate more sparingly, and, if the
regular meal  was much later than usual, had  recourse to
biscuit, fruit, or a slice of  cold  meat, as an intermediate
refreshment, to prevent the  stomach becoming exhausted
from too long a fast.  Following the dictates of experience,
I have long adhered to the  latter plan, and am convinced
that  few who have tried both will long prefer the former.

                    CHAPTER II.
            ON THE PROPER QUANTITY OF FOOD.
Quantity to be proportioned to the wants of the system—Appetite
  indicates these—Cautions in trusting to appetite—General error
  in  eating too much—Illustrations from  Beaumont, Caldwell,
  Head,  and Abercrombie—Mixtures of food hurtful chiefly as
  tempting to excess in quantity—Examples of disease from excess
  in  servant-girls from the country, dressmakers, &.c.—Mischief
  from excessive feeding in infancy—Rules for preventing this—
  Remarks on the consequences of  excess in grown persons-
  Causes of confined bowels explained—And necessity of fulfilling
  the laws which God has appointed for the regulation of the animal
  economy inculcated.
  The  next important  step in the regulation of diet is, te
determine the quantity which ought to be eaten. 
176       TOO MUCH FOOD IS USUALLY TAKEN.
   To ensure easy digestion and sound health, the quantify
of food ought always to be proportioned to the wants of the
system ;  but this can be done only by a constant reference
to the constitution and circumstances of the individual, and
not by attempting to lay down any standaru as admitting
of universal application.
   We have seen that, where waste  is  great and growth
active, an abundant supply of food is required, and that, is
accordance with this relation, it  is in such  circumstances
that  the  desire  for  food is  most keenly felt.   Generally
speaking, appetite is a safe guide as to quantity ; but, in fol-
lowing its dictates, we must take  special care neither to eat
so fast as to prevent it from giving timely intimation that
we have  had enough, nor to confound the mere gratification
of taste, or the yearning of a vacant mind, with the natural
craving of unsatisfied want.   Dr. Beaumont's  remarks on
this  subject  are characterized by so much  soundness of
judgment, that no- apology  can be required for  soliciting
the attention of the  reader to the fallowing very pertinent
extract from his work :
   "  There is no subject of dietetic  economy,"  says Dr.
Beaumont, " about which people err so much as that which
relates to quantity.   The medical profession, too, has been
accessory to this error, in giving directions to dyspeptics to
eat until a sense of satiety is felt.   Now, this feeling, so
essential to be  rightly understood, never  supervenes until
the invalid  has eaten  too much, if he have an  appetite,
which  seldom fails  him.   Those even who are not other-
wise predisposed to  the complaint, frequently induce a di*-
eased state of the digestive organs by too free indulgence
of the appetite.   Of this fact the medical profession are,
generally, not sufficiently aware.   Those who  lead seden-
tary  lives, and whose circumstances will permit of what  is
called  free living, are peculiarly  obnoxious to these  com-
plaints.  By paying  particular attention to their sensations
during the ingestion of their meals, these complaints may
be avoided.   There appears to be a sense of perfect intelli-
gence conveyed from the stomach to the encephalic centre,
which, in health, invariably  dictates what quantity of ali-
ment (responding to  the sense of hunger and its due satis-
faction) is naturally required for the purposes of life ; and
which, if noticed and properly attended to, would prove th©
EAQtit salutary monitor of health,  and  effectual preventive 
INDICATIONS OF A SUFFICIENCY OF FOOD.      177
of disease.  It is not the sense of satiety, for this is beyond
the point  of healthjul indulgence, and is Nature's earliest
indication of an abuse and overburden of her powers to re-
plenish the system.   It occurs immediately previous to this,
and may be known  by the pleasurable sensation of -perfect
satisfaction, ease, and quiescence of body and mind.   It  is
when  the stomach  says enough, and  is distinguished from
satiety by  the difference of the sensations—the former feel-
ing enough—the latter too much.   The first  is produced by
the timely reception into the stomach of proper aliment, .in
exact  proportion to the requirements  of Nature, for the
perfect digestion of which a definite quantity  of gastric juice
is furnished by the proper gastric apparatus.   But to effect
this  most agreeable of  all sensations  and conditions—the
real  Elysian satisfaction of the reasonable epicure—rtimely
attention  must be paid  to the preliminary processes, suca,
as thorough mastication and moderate or slow deglutition.
These are indispensable to the due and natural supply of
 the  stomach at the stated periods of alimentation ; for  if
food be swallowed  too fast, and pass  into the stomach im-
perfectly  masticated, too much is  received in a short time,
and  in too imperfect a state  of preparation  to be  disposed
of by the  gastric juice.
   " The  quantity of gastric juice, either contained in its
proper vessels or in a state of preparation in  the circulating
fluids, is  believed to be in exact proportion to the proper
quantity of aliment required  for the due supply of the sys-
tem.   If a more than ordinary quantity of food be taken, a
part of it  will remain undissolved  in the stomach, and  pro-
duce the  usual unpleasant symptoms of indigestion.   But
if the  ingestion of a large quantity be in proportion to the
calls of nature, which sometimes happens after an unusual
abstinence, it is probable that more than the usual supply
of gastric juice is  furnished ; in which case the  apparent
excess is  in exact ratio to the requirements of the economy,
and never fails to produce a sense of quiescent gratification
and  healthful enjoyment.  A great deal depends on habit
in this respect.  Our  Western  Indians,  who frequently
undergo long abstinence from food, eat enormous quantities,
when  they can procure  it, with impunity."*

  * Experiments and  Observations on the Gastric Juice and Phy-
siology of Digestion, by William Beaumont, M.D.  Reprinted with
notes by Andrew Combe, M.D.   Edinburgh, 1838, pp, 54-56. 
178
rNTEMPERANCE IN EATINO
   If the purposes for which eating is necessary be kept ire
 mind,  the keen appetite and vigorous digestion observable
 in growing youths, and in those who undergo much active)
 exercise in the open air—and the weaker appetite and fee-
 bler digestion observed during  the  middle  period of life,,
 especially in persons of sedentary habits—will appear to be
 in strict harmony with the wants of  the system in the res-
 pective circumstances.   But, from no attention being paid
 by either the old or the young to the principle by which the
 supply of nourishment ought to be regulated, and the hasto
 with which every one labours  to appease  the cravings of
 hunger, it may be affirmed, as a general fact, that mankind
 eat greatly more than, is required for their sustenance ;  and
 the  indigestion thereby induced  is a salutary provision of
 Nature  to prevent the  repletion which would otherwise-
 ensue-.                                   «
   Sir  Francis Head, in his humorous book entitled Bubbles
 from  the Brunnens of Nassau, by an  Old Man, expresses
 his astonishment  at the " enormous quantity of provisions '*
 which the invalids and sojourners at these watering-places
 u so placidly  consume;" and, after noticing  " the heavy
 masses which constitute the foundation of the dinner, and the
 successive layers of salmon—fowls—puddings—meat again
 —stewed fruit—and, lastly, majestic legs of mutton—which
 form the lighter superstructure^" he adds, " Nothing which.
 this world affords could induce  me to feed in this gross
 manner.  The pig which lives in his sty would have some
 excuse, but it is really quite shocking to 3ee any other ani-
 mal overpowering himself at mid-day with such a mixture
 and superabundance of food." (P. 71.)   In another page he
Teturns to the  subject, and quaintly enough remarks, " that
 almost every malady to which the human frame is subject
 is, either by highways or byways, connected with the sto-
 mach ; and I must own, I never see a fashionable physician
 mysteriously counting the pulse of a plethoric patient, or,'
 with a silver spoonon his tongue, importantly looking down
 his red inflamed gullet, (so properly termed by Johnson ' the
 meat-pipe,') but I feel a desire to exclaim, ' Why not  tell
 the  poor gentleman at  once—Sir, you've eaten too much,
 you've drunk  too  much, and you've  not  taken  exercise-
 enough !'   That  these are the main causes of almost every
 one's  illness, there can be no greater proof than that those
 •avage nations which live actively and temperately hav» 
A PREVAILING ERROR IN SOCIETY.        179
only one great disorder—death.  The human frame was
not created imperfect—it  is we ourselves who have made
it so ;  there exists  no donkey in creation so overladen as
our stomachs; and it is because they groan under the weight
so cruelly imposed  upon them, that  we see people driving
them before them in herds to drink at one little brunnen."
(P. 91-2.)
   Our supposed " Old Man " is by no means singular in his
opinions.  The celebrated Roman physician Baglivi, who,
from practising  extensively among Catholics, had  ample
opportunities of observation, mentions that in Italy an un-
usually large proportion of the sick recover during lent, in
consequence of  the lower diet which is  then observed as
part of their religious duties.  This fact is at once a testi-
mony in favour of temperance, and a proof of the assertion
that excess  in quantity is a prevailing error in society.
   Professor Caldwell, of  the United States, in ene of his
vigorously conceived and very instructive essays, inveighs
eloquently against  the intemperance of his countrymen in
eating as well as in drinking, and tells them that one Ame-
rican consumes  as much food as two  Highlanders  or two
Swiss, although the  latter are among the stoutest of the
race.   " Intemperate eating," says he, " is perhaps  the
most universal fault we commit.  We are all guilty of it,
not occasionally, but habitually, and almost uniformly from
the cradle to the grave.   It is the bane alike of our infancy
and youth, our maturity and age.  It is infinitely more com-
mon than intemperance in drinking ; and the aggregate  of
the mischief it does is greater.  For every reeling drunkard
that disgraces our country, it contains one hundred gluttons
—persons, I mean, who  eat to excess  and suffer  by tha
practice."  " How, indeed," he afterward  exclaims, " can
the case be  otherwise, while children and youth are regular-
ly taught, hired, bribed, or tempted to over-eat themselves
from their birth !   Do  you ask me for  evidence in proof
of this charge1?  Go to our dining-rooms,  nurseries, fruit-
 shops, confectionaries, and pleasure-gardens—go even t<J
 sick-rooms—and you will find it in abundance.   You will
 witness there innumerable scenes of gormandizing, not only
 productive of disease in  those  concerned in them, but in
 many instances offensive  to beholders.  The frightful  mesa
 often consists of all sorts of eatable materials that can be
 collected and crowded together; and its  only measure is 
180
INTEMPERANCE IN EATlNfl
the endurance of appetite and the capacity of the stomach.
Like the ox in rich pasture-ground, or the swine at his swill-
trough, men stow away their viands until they have neither
desire nor room for any more.   I do not say that such eat-
ing matches always and everywhere occur among us.   But
I do say that they occur too frequently, and that they form
fit subjects for caricature  pictures, by European tourists, of
our domestic manners.  I add, however, that similar scenes
present  themselves  in every country I have visited, where
provisions are abundant and cheap."*
  This is a strongly drawn picture, but, with a modification
in degree, it is perhaps not less applicable to our own and
other European countries than to the United States.   The
" Old Man's " description of German feeding is, in its main
features, essentially the same ; and, so  far as my observa-
tion and experience go,  it  is only in a less degree that we
fall short of our brethren in America.   As a general rule,
we also exceed, though  not to the  same  extent.  This is
owing partly to our more advanced civilization, and partly
to the greater difficulty of  procuring the means of excess ;
and if 1 have resorted to Germany and the United States
for the  most striking illustrations of the principle, it is not   t
from want of examples at home, but because we are so much
more alive to the errors of our neighbours than to our own,
that the principle involved  in their commission will be more
readily  recognised when pointed out in them than when its
perception is made to imply condemnation of  ourselves.
   It is  a trite observation,  that medical  men are constantly
exclaiming against the eating propensities of their patients,
and inculcating the practice of temperance.   An eminent
physician of the  present day  says, " I believe that every
stomach, not actually impaired by organic disease, will per-
form its functions if it receive  reasonable attention ; and
when we consider the  manner in which  diet is generally
conducted, both in regard  to quantity and to  the variety of
articles of food and drink which are mixed up into one
heterogeneous mass, instead  of being astonished at the
 prevalence of indigestion, our wonder must rather be, that,
 in such circumstances, any stomach is capable of digesting
 at all    In  the regulation  of diet much  certainly is to be
   * Transylvania Journal of  Medicine for September, 1832, p. 313
  Bee also Dr. Caldwell's excellent Thoughts on Physical Education,
 and the True Mode of Improving the Condition of Man ; reprinted
 for A. & C. Black, Edinburgh, 1836. 
A PREVALENT CAUSE OF INDIGESTION.       181
done in dyspeptic  cases, by attention to the quality of the
articles that are taken ;  but I am satisfied that much more
depends upon the quantity ; and I am even disposed to say,
that the dyspeptic  might be almost  independent of any
attention to the  quality of his diet, if he rigidly observed
the necessary  restrictions in regard to quantity."*   The
latter opinion, which is in perfect harmony with Dr. Beau-
mont's observation of the power of digestion being limited
by the amount of gastric juice which the stomach is capa-
ble of providing—an amount varying with the wants of the
system, and, consequently, with the mode of  life—is also
forcibly, though quaintly, supported by a late popular writer,
who affirms that " it is your superfluous  second courses,
(which are  served up more to gratify  the pride  of  the
host than the appetite of the guests,) that overcome the
stomach  and paralyze digestion, and  seduce  children  of
larger growth to sacrifice the health and comfort of several
days—for the baby pleasure of tickling their tongues for a
few minutes with trifles  and custards "t
   Cornaro,  Cheyne, and others, have, most absurdly,  at-
tempted to  determine a standard  quantity of food  for  all
mankind, and have  fixed it at the lowest  possible limit.
The very attempt, however, is inconsistent with  the  laws
of the animal economy  ; since  the  supply required must
necessarily vary, not only  according  to  the age, sex, and
constitution of the  individual, but according to the mode
of life and  the circumstances by which he is surrounded :
and it" would be, therefore, not less injurious than unnatural
for any one to adhere to  the same invariable proportion.   I
have seen several  instances in which  young men have suf-
fered considerably  from  adopting for a time the low scale
of diet recommended by  Cornaro, or from living exclusively
on  vegetables, without  regard to the  urgent demand for a
full supply of nourishing food necessarily excited  by the
active bodily exertion in which they engaged.
  . Mixtures of different kinds of food are strongly condemn-
ed by almost all writers  on dietetics  as injurious  to diges-
tion.   They seem  to  me, however,  to produce  mischief
much  more  by the  inducement to excess in quantity which
vaiiety affords, than by  the mere mixture of different sub-
stances. In a healthy stomach indigestion is rarely, if ever,
 » Abercrombie on Diseases of the Stomach, &o.  1st edition, p. 73,
 J The Art of Prolonging and Invigorating Life.  3d ed., p. 168. 
182     FOOD TO BE PROPORTIONED TO ACTIVITY.
induced by eating several kinds of food at one meal, provided
the total amount consumed be not beyond the wants of the
system, and do not exceed the due proportion to the quantity
of gastric juice which the stomach is able to provide.  When
only one dish is partaken of, there is less temptation to ex-
ceed in quantity than where several are tried.
  The first intimations of satisfied appetite are unquestion-
ably the best warning we can have when to stop eating.
If we do not go beyond this point, the subsequent sensa-
tions are pleasurable and invigorating,  and, after a brief in-
terval, we are perfectly disposed to return to active exertion.
But if we eat more  than  enough, fulness and oppression
are almost immediately experienced,  and a considerable
time must elapse before either mind or body can effectually
resume its activity.
  Where, from  long over-indulgence  or  other causes, the
appetite cannot be safely followed as a guide in regulating
the quantity of food, we shall  not err very far if  we pro-
portion our meals to the amount of the preceding exercise.
When this has been active and in the  open air, and waste
has consequently been  considerable, a liberal allowance of
food will  be  more easily  digested than  perhaps half the
quantity would be after a week's inaction.  Hence it is a
great error to devour the same quantity of food daily, what-
ever our mode of life and bodily exertion may be ; because
" the strong food which the strong action of strong bodies-
requires will soon destroy weak ones, if the latter attempt
to follow the example of the former; instead of feeling in-
vigorated, their stomachs will be as oppressed as a porter
is with a load that is too heavy for him—and under the
idea of swallowing what are called strengthening nourish-
ing things, will very soon make themselves ready for the
undertaker."*'  And yet nothing is more common than to-
see persons who have passed from a life  of varied  activity
to one of a purely sedentary nature, continue to eat—merely
because they have been accustomed to- it—as much  food
as if  they were still engaged in constant bodily exertion.
Many females of the higher and middle classes, who scarcely
ever stir out of doors, except to church, nevertheless make
as hearty meals twice or thrice a day as if they were under-
going pretty severe exertion ;  but they sooner or later  reap
their reward, and,  after groaning for a  time under the bur-
             * Art of Invigorating,. &c, p. 171. 
        ADAPTATION OF DIET TO CIRCUMSTANCES.     183

den which they have placed upon their own shoulders, they
either obtain relief by the forced  adoption of a temperate
regimen, or "fall into the hands of the undertaker."
   In  towns we often observe the bad effects of over-feed-
ing in young female servants recently  arrived from  the
country'.  From being accustomed to constant exercise in
the open air, and to  the comparatively innutritious diet on
which the labouring classes subsist, they pass all at once,
with appetite, digestion, and health in their fullest vigour,
to the confinement of a house, to the impure atmosphere
of a crowded city, and te a rich and stimulating diet.   Ap-
petite, still keen, is freely indulged ;  but waste being dimi-
nished,  while nutrition  is increased, fulness is speedily in-
duced, followed in its turn by inflammatory disease or fever,
which sometimes cuts  short  life, where, with better ma-
nagement, health might have been preserved  for  years.
In many  instances, again,  life is saved by the digestive
powers being the first  to give way, and refusing either to
receive or to concoct the same quantity of aliment  as be-
fore,  and the patient then escapes with the minor evils of
protracted  indigestion.  This latter result ensued in  an
instructive  case mentioned by Heidler, where a moderate
acquaintance with the laws of the  animal economy might
have saved months  of suffering, and even of danger, to the
patient.—" A  young woman of  a healthy constitution,
brought up in all the simplicity of country habits, passed at
once, on her marriage,  to a less active mode of life,  and to
a much more elegant table.   In  a short  time she began ta
complain of irritability,  lassitude, various spasmodic  sensa-
tions, and habitual constipation.   Hypochondria was soon
added  te the  ether symptoms ;  her hope of becoming a
mother being always deceived, an additional glass of wine,
Dark, and other tonics  were ordered.  The evil increased.
The  patient became melancholic, and believed that she was
always swallowing  pins.   In the course  of the year she
became so emaciated and yellow, that her mother,  who had
 not se"en  her for eleven months, could scarcely recognise
 her.   After an eighteen months' course of purgatives and
 two courses of Marienbad-water, she entirely recovered."*
 If the medical adviser  first consulted in this case  had pos-
 sessed the slightest acquaintance with the principle I have
   * Heidler, Marienbad, et ses differens moyens curatifs dans les ma
 ladies chroniques, p. 62. 
184     ADAPTATION OF DIET TO CIRCUMSTANCES'.
been explaining, he would no more have regarded wine and1
tonics  as the best remedies for the  oppressive languor of
excessive feeling, than he would have sought to extinguish
a flame by pouring oil into the fire.
   The operation of the same principle is equally conspi-
cuous  in girls sent from the country to the work-rooms of
fashionable milliners and dressmakers in the larger towns.
Accustomed to constant and varied activity in the open air,
they are  transferred at  once to confinement all  day, and
even to a late hour at night,  in the impure atmosphere of
a crowded work-room, and there engaged in sedentary oc-
cupations of the  most monotonous description, which, so far
from allowing them any opportunity of enjoying adequate
muscular exercise,  scarcely admit of their  even changing
their position. Under such circumstances little waste takes
place,  and the appetite and digestive powers both give way,
because less food is now required to repair the diminished
loss.   If the individual adapts her eating to her change of
circumstances, she may escape severe disease ; but if, as
generally happens, from pure ignorance, she continues to
eat to the same extent as before, headaches, sickness, bilious
disorder, and indigestion will be among the smallest of her
evils, and she will have reason to be thankful if she does
not become  the  victim of confirmed bad health.    In esta-
blishments of this description the provision of the means of
exercise, even by dumb-bells, shuttlecock, or otherwise, in
a large room with open windows for a few minutes, several
times a day, would  not  only  prevent  much suffering, but
even repay itself in an economical point of view, by produc-
ing an increased aptitude for work and less frequent absence
on  account  of illness.  In these days of wide-spreading
philanthropy, considerations of this kind ought to be more
attended to.
  The necessity of proportioning the supply of food to the
expenditure  incurred and to the mode of life, is still farther
illustrated in the case of individuals changing from an agri-
cultural or other employment carried on in the open air in
the country, and involving no very great bodily labour, to one
of a mechanical  kind carried on in an impure atmosphere
in a city, and requiring a severe and continued muscular ex-
ertion.   It is a matter of experience, for example, that the
stout young men from the country, who  are generally se-
lected  as apprentices for the laborious occupation  of letter 
ERRORS OF DIET IN INFANCY.           185
press printing, almost uniformly break down during the first
ten or twelve months, and it is only after some years' train-
ing that they are able to withstand the  fatigue.   The viti-
ated atmosphere  in  which they work  has some share in
producing this result, but  the chief cause is undoubtedly
the inadequacy of their ordinary diet to repair the great ex-
penditure of muscular energy to which they are  habitually
subjected, and for which they have not been previously pre-
pared.   In the office where this volume is printed, four
strong and healthy lads were engaged  in the summer of
1835 as pressmen, and put to work along with an equai
number of experienced men.  Before the following February
every one of the former had been laid up from sickness for
weeks, although the whole of them are of the most sober
and steady habits ;  while not one of the older  and more
experienced men felt any inconvenience from his exertions.
This very instructive fact is also deserving of attention, as
corroborating what I have elsewhere said in Tegard to the
necessity of proper management during the period of transi-
tion from youth to manhood—a  period during two or three
years of which more good or more mischief may be done
to  the human constitution  than during almost any other ten
years of life.*  That, in times past, pressmen have suffered
at least as much from their own mismanagement as from
the nature of their  employment, is rendered  probable by
their proverbial dissipation.   In utter ignorance  of  the
structure and laws of the animal economy, they not unnatu-
rally sought to relieve the exhaustion under which they suf-
fered,  by the stimulus of  spirituous  and other intoxicating
liquors, instead of seeking it—where only it can  be effectu-
ally obtained, and at a cheaper rate—in a more wholesome
and nourishing diet.  It is gratifying to perceive, however,
that in this, as in many other  trades, the progress of know-
ledge is already leading to the prevalence of more rational
ideas, and to the consequent formation  of better habits.
   There is no period of life during which it ^s  of greater
importance to follow the intentions of  Nature in the regu-
lation  of diet, both as to quantity and  quality, than  during
the earliest part of childhood ;  for at no period is the neglect
 of them more fatal.  Surprise is sometimes expressed at
 the number of children who are carried off before complet-
  * Principles of Physiology, &c., tenth edition, chap, x., p. 290, and
chap, iiii
                          16* 
186          ERRORS OF DIET IN INFANCY".
 ing their first or second year ; but  when wc consider  the
 defective  education  and entire ignorance  of the human
 economy, not only of the nurses and servants  to  whoso
 care the yTJung are intrusted, but of the parents themselves.
 our wonder ought  to become greater that so many survive
 than that so many die.  There is, perhaps, not one mother
 in ten thousand who, before becoming such, has ever in-
 quired into the nature and wants of the newly-born infant,
 or knows on what principles its treatment ought to be direct-
 ed ; and hence the hurtful and superstitious notions of the
 human economy which still linger in the nursery, long after
 they have ceased to  prevail in the world of science.
  Those whose opportunities of observation have been  ex-
 tensive will agree with me in opinion, that at least one-half
 of the deaths occurring during the first two years of exis-
 tence are ascribable to mismanagement and to  errors in
 diet.   From pure  ignorance many mothers consider every
 expression of  uneasiness as an indication of  appetite, and
 whenever  a child cries  they  offer  it the breast  again,
 although ten minutes may not have  elapsed since its pre-
 ceding repast.  Nothing  can be more injurious  than this
 custom.   It overloads and oppresses the stomach—excites
griping and bowel-complaints, restlessness and fever—and
not unfrequently leads to fatal disease in the brain.  It does
harm also  by  withdrawing the mother's notice  from  the
real source of uneasiness.
  It is  astonishing,  indeed,  with what exclusiveness of
understanding eating  is regarded even by intelligent parents
as the grand  solatium or panacea  for all  the pains and
troubles which afflict the young.   If a child falls  over a
stone and bruises its  leg, its cries are immediately arrested
by a sugar-biscuit stuffed into its open mouth.  If its temper
is discomposed by  the loss of a toy, it is forthwith soothed
by an offer of  sweetmeats, the ultimate effect of  which is
to excite colicky pains in its  bowels, which  are worse than
the  original  evil, and  for which, in their turn, it is presented
with " nice peppermint drops," or some other equally plea-
 sant antidote.  Because the  mouth is open when the child
 is crying,  and the mouth leads to  the stomach, parents
 jump to the conclusion  that it is open for the purpose of
 being filled, and proceed to cram it accordingly ; forgetting
 all  the while that  the mouth leads  also to the windpipe,
 and may be open for the  admission of air to the  lungs as 
             CONSEQUENCES OF OVER-EATING.         187

Well as of food to  the stomach—and that if they stuff it
with cake or pudding when it is open only for the reception
of air, they run the risk of suffocating the little  innocent
when their only wish  is to  sooth him.  Everybody must
have seen fits of convulsive cough induced by fragments of
food being drawn into the windpipe in such circumstances.
  To confound crying and the expression of pain with the
cravings  of hunger, is far from being a  matter of indiffe-
rence to  the child.  If food be given when it wishes only
to be relieved from suffering, the offending cause is left in
activity,  and  its effects  are  aggravated  by the additional
ill-timed distension of its stomach.  But so far is this im-
portant truth from being sufficiently impressed on the minds
of parents and nurses, that nothing is more common, when
the infant refuses to swallow more, but still continues to
cry, than to toss it in the nurse's arms, as if on purpose
to shake down its food, and then resume the feeding-   And
in such attempts it is  too true that the perseverance of the
nurse often gets the  better of the child, and forces it at
last to receive the food at which it really loathes.
  In  the former editions of this work  I  took considerable
pains to  point out  the  principles  according to which diet
ought to be regulated during the first months of  life ; but
as  the subject has since been very fully discussed in my
Treatise on the Physiological and Moral Management of
Infancy, of which  a new edition has been lately published,
I have thought it unnecessary to enter into farther detail here.
  That the prevalence of over-eating is  a general error in
society, especially among the sedentary classes, is strongly
presumable, even  without direct  proof,  from two almost
characteristic circumstances—namely, the frequency  of
indigestion in one  or other of its  numerous forms, and the
almost universal use  of purgative medicines, with a view
to remove from the system the superfluous materials which
have  been poured  into it without any natural demand.
  It is perfectly certain that, in the natural state of man, the
bowels are quite able to act  regularly without the aid of
laxatives.  If they are not, the Creator must have failed in
accomplishing his aim—a conclusion which no rational mind
can arrive at.   If, on  the other  hand, they are  intended
and constituted to  act without external  aid, it necessarily
follows that a wide departure from the order of nature  must
have taken place somewhere, to produce the  inactivity 
 188         CONSEQUENCES OF 0VER-EATIN9.

 which is now so generally complained of, especially among
 the middle  and higher classes, and  among  females.   On
 the principle we have laid down, of nourishment requiring
 to be proportioned to waste, it will not be difficult to explain
 in what this departure consists.  It is in the mode of life
 being by far  too sedentary to admit either of the natural
 waste, which alone renders nourishment necessary, taking
 place, or of that constantly recurring contraction and relaxa-
 tion of the abdominal and respiratory muscles, which have
 been  pointed out  as  aiding so effectually  the  peristaltic
 motions of the intestinal canal.  If, in conformity with the
 diminished wants of the system, we reduce the quantity of
 food and increase  the exercise, neither the  oppression of
 repletion nor the  need of opening  medicine  will be felt.
 But if, along with  diminished  exhalation and diminished
 muscular  action, we persevere in eating copiously of nutri-
 tious aliments, either digestion must fail, the system become
 too full, or  some  artificial stimulus be given to  aid  the
 bowels in expelling its superfluous aliment.
   Such, accordingly, are the results observable in every-day
 life.  One  is saved for a time from  more serious  evils by
 his stomach becoming enfeebled, and refusing to digest the
 excess of nourishment which it receives.  In another, whose
 digestion is more vigorous, the system becomes full and ex-
 cited to the brink of active orinflammatory disease, a sudden
 attack of which hurries him to the tomb.   While a third gets
 rid of the load  by  stimulating the bowels to  higher action
 than is natural to the mode of life ;  in other words, artificial
 waste is excited by purgatives, to supply the place of that
which  ought to result from the active use of the bodily
powers, and which alone renders a full diet proper or safe.
   It is not enough, then,  to sit by the fire, blame Nature,
 and lament over our unfortunate constitution, which obliges
us to make such constant use of medicine.    In the great
 majority of instances Nature is more willing  to do her part
 than we are to do ours, and all that she requires of us is, to
 fulfil those  conditions without which she is powerless, and
 we are sufferers and unhappy.  If we  exercise our minds
 and bodies  in healthful occupation, and seek to inhale the
 pure atmosphere which God has spread around us, so as to
 impart that gentle impulse  to the stomach and bowels which
 I have  already  described as necessary to their action, we
 shall have no need of laxatives to assist them.  But if we 
            CONSEQUENCES OF OVER-EATIXG.    «    189

choose  to neglect His laws, and to live in bodily inaction
within doors, and  thus  deprive  the bowels of  all natural
aid, let us at least  take  the  blame to ourselves, and not
unjustly throw it upon the Ruler whose injunctions we thus
practically despise.   And if, while leading this inactive life,
we continue to gratify taste by eating much more than waste
requires, and thus stand in  need of purgatives to enable us
to throw off the load, let us at least be jpst, and, instead of
lamenting over a defective  constitution, let us deplore the
ignorance which has hitherto blinded us to the perception
of the truth, and led us to blame a Being whose arrange-
ments are so evidently intended for our happiness.
   During the active years of childhood and youth, when
a strong instinct impels to much locomotion in the open
air, how rarely do we find  the stimulus of purgatives ne-
cessary  to the proper  action of the bowels, except after
errors in diet, or some  unusual accident!   And  what is it
that  induces imperfect activity in later years,  if not the
change  in the habits, occupations, and mode of life 1  If
the lively and bounding girl, whose loose and unconstrained
attire admits of the  freest  motion and fullest respiration,
passes in a few months  from the exuberant and  playful
indulgence of her feelings,  intellect, and muscular system,
to the quiet and composed inaction and confined dress ot
a sedate young lady, who  never walks  out, except at a
measured pace to school or to church, is it really wonder-
ful that, with an undiminished diet, her stomach and bowels
should begin to act with less vigour, and that, in time, her
constitution should be so far impaired as to render neces-
sary  the constant use of laxatives 1   The stomach and
bowels,  in fact, are regarded very much as if  they were
independent powers residing within us, and placed  there
purposely for our molestation.   So many  heavy charges
are continually brought against them, that they can scarcely
ever  be  found in the  right.  They are blamed for every act
of mischief which cannot  be clearly proved against any
other organ ; and yet, influential as they are in affecting our
comfort, they are treated  by us with very little care or cere-
mony.  Their powers and wishes are consulted in nothing,
but their backs are loaded,  at the caprice of their owners,
worse,  as  Sir F.  Head  observes, than any pack-horse;
nevertheless, we abuse them most emphatically  when they
sink to the  earth overwhelmed by the weight imposed on 
190
DIET IN MATURE AGE
them.   They are, in short, the scape-goats which must bear
all our physiological delinquencies, and save us the pain of
blaming ourselves.  If they feel uneasy after a heavy meal,
it is not we who are to blame for having eaten it.'  No ; it
is the fish which lies heavy on the stomach, or the  stomach
which  is unfortunately at war  with soup, or potatoes, or
come other well-relished  article   We  have  nothing to do
with the mischief, except as meek and  resigned sufferers.
We never eat more than  enough.   We never devour lob-
sters, or oysters, or salmon, or  cheese, or anything which
experience has told us our enfeebled stomachs cannot digest!
We  are too  prudent and self-denying for that.   And yet,
somehow or another, our stomachs  get hold of all  these
things  in spite of us. and we must pay the same penalty as
if we had eaten them deliberately, and with malice prepense!
The case  is hard, no doubt, that we cannot  lead  indolent
and slothful  lives, and yet enjoy the incompatible luxuries
of having the appetite of a rustic and the  digestion of a
tiger:  but, since we are  so  unfortunately constituted that
we must act like rational creatures or suffer the penalty,
would  it not  be a wise proceeding to set a better watch on
the stomach, and try to subject it to  more effectual control 1
  In mature  and middle age, after  the effervescence and
boisterous activity of youth are over, still greater caution
than before becomes requisite.  Growth no longer goes on,
and  nourishment is needed  merely  to supply waste ; and,
accordingly, the appetite becomes less keen and the power
of digestion les6 intense.   If the individual continues from
habit to eat as heartily as before, even after changing to a
sedentary  mode of life, the natural  vigour of the digestive
system may  enable it to withstand  the  excess for a time,
but ultimately dyspepsia, or some form of disease dependant
on indigestion, wiil certainly ensue.   The attempt to com-
bine the appetite and  digestive power of early youth with
the altered circumstances  and comparative  inactivity of
mature age,  is the true source of the  multitude of  bilious
complaints, sick headaches,  and other analogous ailments,
now so common and  so fashionable in  civilized  society;
and  they will never be got rid of so long as  their exciting
causes are allowed to operate with unrestricted freedom.
   There is  one form  in which adults pay a very heavy
penalty for attempting to combine the  enjoyments of full
living  with an inactive mode of life, and to which, from its 
ADMITS OF CONSIDERABLE VARIETY.       191
frequency, it may be useful to direct  special attention.   I
allude to abdominal congestion,  or that state in which the
circulation through the abdominal veins becomes sluggish
or partially obstructed, and ultimately induces either chronic
indigestion, with great depression of  mind, or other affec-
tions  of a  painful  and  intractable nature.  In  the  great
majority of instances  this  is the true source of the very
common  affection  known  by the name of internal  piles,
which is not only the frequent cause of much suffering and
bad health, but which, when once fully established, can  be
cured only by one of the most painful  operations within the
whole province of surgery.
  But while  habitual temperance in eating and the  adap-
tation of diet to the mode of life are thus strongly inculcated,
I am  far from recommending that we  should calculate with
scrupulous minuteness the weight or bulk of every morsel
that we eat.  The stomach, like every other^organ of the
body, is,  for the wisest  purposes, allowed a certain range,
within which it may exercise its functions without injury
to health ; and it is only in virtue of  such  a power that it
can adapt itself to the different circumstances in which  an
individual may be placed.   If every trifling change in the
quantity or quality of food  were  to be followed by mischie-
vous consequences, no one could retain health for a single
day;  and if the stomach had no power of  partially adapt-
ing itself  to a particular kind of aliment, every change  of
place  and of climate must soon have been attended by the
loss of health and life ; because there  are scarcely any two
places or countries in which precisely  the same food would
be set before us.
  According to this law of adaptation, which, of  course,
has its limits, the stomach may be accustomed to the recep-
tion of either a larger  or a smaller quantity of food than
the necessities of the system require.   If it is accustomed
to too much, and less than  usual be allowed, an unpleasant
feeling of vacuity will arise, accompanied by a  craving for
more  ; but after a few days the  unpleasant sensation will
disappear,  and the feeling  of satisfaction be as great as if
a large meal had been taken, and digestion will become
more  healthy and vigorous ; whereas, if merely to gratify
the temporary craving, more food continues to be  taken
than  the system requires, ultimate bad health  will be the
inevitable result. 
 192        INDIGESTION OFTEN A SAFEGUARD

   This is precisely the error which is generally fallen into.
 The stomach is accustomed, during youth, to receive and
 digest  a larger quantity of food than is requisite to carry on
 growth and repair the ordinary waste of the system after
 maturity has been attained.  From custom, however, we
 continue to fill it as liberally after growth is completed and
 waste is diminished, as we did  before, when  both  were at
 their height.   And if by any chance we eat less for a day
 or two, we mistake the temporary sense of emptiness for
 an indication of appetite, and are not  satisfied till it is re-
 moved.  The natural consequence is, that we educate the
 stomach to demand  more food  than the system requires,
 and more than it can itself continue to digest; and hence
 the numerous evils  which we  daily  witness as fruits of
 indigestion.
   In thus punishing us with the pangs of dyspepsia  as  a
 warning to more  reasonable conduct, Providence displays
 the purest beneficence.  To place this in a clear point of
 view, let us  suppose digestion to continue perfect, notwith-
 standing the daily reception of an excess of food into the
 stomach, the result will necessarily be the regular formation
 of an undue quantity of chyle ; this, in its turn, will produce
 an excess of blood throughout the whole system ; and  the
 individual will thus exist with all his functions in a  state of
 constant oppression, and in continual danger of the  rupture
 of a bloodvessel, till, from mere fulness, some active disease
will be excited, requiring the instant and vigorous  use of
the lancet for its relief, or very probably cutting short life.
If, then, man cannot subject his appetites to  the control of
reason, some other check  against repletion must  be  pro-
 vided ; and, fortunately for us, such a check  is frequently
found in  the  refusal  of the stomach to continue to digest
 the superfluity of food.  In practical life we meet, in fact,
with both results.  There are some persons constituted
 with such vigorous powers of digestion, that no quantity of
 food ever seems to  oppress their  stomachs.  If they eat
 habitually more than is required to supply waste and  sustain
 the system, they speedily suffer from repletion, or some one
 or other of the diseases arising out of its existence, such as
 abdominal obstruction, piles, inflammation,  apoplexy, he-
 morrhage, enlargement of the heart, or morbid growth in
 some organ of the body.  In the greater number, however,
 of those who exceed in quantity, the stomach itself becomes 
BY WARDING OFF GREATER EVILS.         193
 enfeebled by the over-exertion to which it is subjected, just
 as  the muscles do from excess of labour ; and the conse-
 quence is  impaired  digestion,  which  prevents  the  food
 from being duly converted into chyle, and thus protects the
 system from the fulness which would otherwise be induced.
 Accordingly, it is a familiar truth, that  those who eat  most
.are not always the best nourished ; and that, on the con-
 trary, the stoutest men are often those who eat  compara-
 tively little, because that little is thoroughly digested.
   It  is, therefore, of  great importance to be able to  read
 aright the instructions of Nature, and to act in conformity
 with their meaning.   In practical benefit to ourselves it will
 make a great difference whether we regard indigestion as
 merely an accidental and capricious occurrence unconnected
 with conduct, or as purposely meant to warn us from con-
 tinuing to act against laws instituted  to secure  our well-
 being and happiness.  In the former  case we may go  on
 unsuspectingly in the road to destruction till it is  no longer
 in our power to turn back ;  whereas, in the latter, we can-
 not feel a single pang of indigestion without being reminded
 of  some aberration from the path of duty, and seeking to
 return by the shortest way.   It is too true that, even when
 aware that we are  going wrong, we do not  always choose
 to retrace our steps; but it  is not  less true  that we shall
 be  more likely to fulfil the  laws of Nature when we are
 made  acquainted with  their existence  and intention, than
 when left to the guidance of ignorance  alone.   It must be
 observed also, that hitherto mankind have not been taught
 the requisite knowledge till after their habits of action  were
 formed ; and, therefore, no  inference can be  drawn  from
 their conduct in circumstances so unpropitious, which can,
 with  any fairness, be held as applicable to the time when
 knowledge shall be communicated  to  the young as an in-
 dispensable part of a  useful  education.
   If over-feeding be the prevailing error among the middle
 and higher classes of the community, the opposite  condition
 is as unquestionably that of a large proportion of the labour-
 ing poor.   Pressed upon on*all sides by the powerful com-
 petition both of constantly improving  machinery and of a
 superabundant population, the manual  labourer is impelled
 to  undergo an amount of ever-recurring bodily exertion
 which far exceeds  the  natural powers  of his constitution,
 even when supported by the fullest  supply of nourishment;
                          17 
194   DIET OF THE LABOURING CLASSES DEFECTIVE.

and when, as often happens along with this excess of labour,
his food, from inadequate wages, the number of his family,
or his own injudicious management, is defective in quantity
or in quality, the consequences to his health and happiness
are disastrous in the  highest degree.
   To those who have never reflected on the subject, it may
seem  like exaggeration to  say, that, as a general fact, at
least nine-tenths of the lower orders  suffer physically, mo-
rally, and intellectually from being over-worked and under-
fed : and yet I am convinced that the more the subject shall
be investigated, the more deeply shall we become impressed
with the truth and importance of the statement.   It is true
that very few persons die from actual starvation ; but it is
not less  certain that thousands  upon  thousands  are  an-
nually cut off, whose lives have been greatly shortened by
excess of labour  and deficiency of nourishment.  It is a
rare thing for a hard-working artisan to arrive at a good
old age.   Almost all of them become prematurely old,  and
die off long before the  natural term of life.   It  is in  this
way that, as remarked by Dr. Southwood  Smith, the mor-
tality of  a country may be  considered  as an accurate in-
dication  of  the misery of  its inhabitants.  According to
Villerme, the rate of mortality among the poor is sometimes
double that among the rich.  Thus it is found, he says,  that
in a poor district in France one hundred die, while in a  rich
department  only  fifty are carried off; and that, on taking
into account the  whole population of France,  a child born
to parents in easy circumstances has the chance of  living
forty-two and a half  years, while  one born of poor parents
can look for no more than thirty.*
   These  are striking facts, and  their truth is  amply con-
firmed by the registrar-general's annual reports  to parlia-
ment of the births,  marriages, and deaths  occurring in
England and  Wales.   Many causes concur   to  produce
this  melancholy  result; but among the  principal is  un-
questionably the disproportion  so generally  existing be-
tween toil and nutrition   In the army the  operation of
the same principle has long been  recognised in the inferior
strength and  health  of the  privates compared  with  the
officers.   The officers, being  better fed, better clothed,
and better lodged than the common soldiers, bear up  suc-
cessfully against fatigue and temporary privations by which
           * Smith's Philosophy of Health, chap. iv. 
      MORAL AS WBLL AS PHYSICAL DETERIORATION.  195

the latter are overwhelmed.   During epidemics, too, the
poor, from their impaired stamina, almost invariably become
victims  in  a proportion far exceeding  that  of the more
wealthy classes.   This is, no doubt, partly owing to their
greater intemperance and want of cleanliness ;  but even
these  vices often derive their origin from  the same root—
the want of adequate repose and comfortable sustenance.
  The bad consequences of defective nourishment are not
confined  in their operation to the  bodily constitution of the
labouring poor.   Their minds also are deteriorated.  The
pressure of poverty is unfavourable to the  growth of refine-
ment  and morality, and crime and turbulence are never so
much to be dreaded as during times of scarcity, and manu-
facturing or agricultural  distress.   Bodily health, satisfied
appetite, and peace of mind are great promoters  of  indivi-
dual morality and  public tranquillity ;  and whenever these
are encroached upon in any great class of the  community,
discontent and crime are sure to follow.   Even as I write,
fresh and irresistible evidence  of  this great truth has just
appeared (August, 1841) in a circular addressed to mem-
bers of parliament by the association for  procuring an
OFFICIAL INQUIRY  INTO THE PAOPERISM OF SCOTLAND,  and
from  which it will be sufficient for my present purpose to
quote only a few  lines.   At page 4 it is said, " Of the
effect of the extensive destitution at Glasgow on crime, no
farther evidence than the following extract from a letter of
Captain  Miller to  this committee, will be  required by those
who are aware of  the character and public services  of that
officer:
   " Should farther information of any kind  regarding the
state of pauperism here be required, I  shall be  glad  to
furnish it if in my power, as  I think it imperatively neces-
sary, not merely  on the ground of.humanity, but also  as a
means of repressing crime, that some better provision should
be made for the destitute poor, and particularly  in the popu-
 lous  districts of  the country.   I need scarcely say,  that,
 from the nature of my duties, I have opportunities of seeing
 the actual wants and privations  of the poor, and the ten-
 dencies of these on their moral condition, to an  extent not
 falling under the  eye of every one, and which induces me
 the  more, though I can  ill spare time,  to wish to be  of
 service, if I  can, in meliorating their condition."  With
 this  testimony before us, it will  scarcely be denied that in 
 196       RESULTS FROM DEFECTIVE NUTRITION.

 legislation the principle  here inculcated  is far too little
 attended to, and that laws are consequently enacted merely
 for the suppression of the result, while the source from
 which it springs is left altogether unnoticed and  in  the
 fullest activity.
   Among  the  poorer  classes the children as well  as  the
 parents suffer  much,  both physically  and morally, from
 insufficient food.   Their diet, being chiefly of a vegetable
 nature, and consisting of porridge, potatoes, and soups, with
 very little butcher-meat, proves far from adequate to carry
 on vigorous growth in the one or repair waste in the  other ;
 hence arise in the young an imperfect developement of the
 bodily organization, a corresponding deficiency  of mental
 power, and a diminished capability of resisting the causes of
 disease.   In work-houses  and dther charitable institutions
 ample evidence of these  deficiencies obtrudes itself upon
 our notice, in the weak and stunted forms and very mode-
 rate capacities of  the children.   Under an impoverished
 diet, indeed, the moral and intellectual capacity  is deterio-
 rated as  certainly  as the bodily; and a full exposition  of
 this fact, and the  principles on which it is founded, would
 be a great public benefit.
   Even  among the children of the wealthier  classes a
 sufficiency of nourishing food is not always provided with
 the care  which it deserves. Both in families and in  board-
 ing-schools it is no  uncommon practice to stint the healthy
 appetites of the young, or to feed them  with  soups and
 other eatables which contain too little nutriment in propor-
 tion to their bulk.   I am acquainted with many instances
 of this most injudicious error, and have seen scrofula and
 severe digestive affections brought on by persevering in it
through sheer ignorance,  and  even in the  belief  that such
 " temperance " was healthful.   Where adequate exercise
is  permitted, and  the food is plain and nourishing, hurtful
excess in eating will rarely occur, at least in healthy chil-
dren. 
197
                   CHAPTER III.
CONDITIONS TO BE OBSERVED  BEF0RT3 AND AFTER EATING.
General laws of organic activity apply to the stomach as well as to
  other parts—Increased flow of blood toward the stomach during
  digestion—Hence less  circulating, in other organs—And, con-
  sequently, less aptitude for exertion  in them—Bodily rest  and
  mental  tranquillity essential to sound  digestion—Rest  always
  attended to before feeding horses—Hence also a natural aversion
  to exertion immediately after eating—Mischief done by hurry-
  ing away to business after meals—Severe thinking hurtful at
  that time—Playful  cheerfulness after dinner  conducive to di-
  gestion—rThe  mind often the cause of indigestion—Its mode
  of operation explained—Also influences nutrition—Illustration
  from  Shakspeare—Importance of attending to this condition of
  health enforced.
   Having now discussed the principles by which  the num-
ber and  quantity of our  meals ought to be regulated, we
have next to consider the conditions required for the healthy
performance of digestion after the  aliment has reached the
stomach, and to deduce from  them such practical rules as
shall tend to facilitate  the  accomplishment of the process.
   Among the circumstances  which favour digestion, the
observance of bodily rest and mental tranapillity for some
time before  and after every meal  is perhaps the most im-
portant ; its influence depends on  a well-known  law of the
animal economy, already frequently alluded to, but to which,
that it may be fully understood, I must again shortly refer.
   Whenever any living part is called into vivid action, an
increased flow of blood and of nervous energy  toward  it
immediately commences, to enable  it to sustain the requisite
degree of excitement,  and continues till some time  after
 the activity has ceased.  In accordance with this law, when-
 ever food is swallowed, the lining membrane of the stomach
becomes suffused with blood, and,  owing to the greater dis-
 tention of its vessels, its colour changes from a pale pink to
 a deep red hue.  After digestion  is completed and the un-
usual  supply of blood is no longer required, the vessels again
 diminish, and the  colour  returns  to its original  tint.   In
 St. Martin's stomach  these changes were  so often  seen
by Dr. Beaumont, as  to render their occurrence as  fully
 demonstrated  as any circumstance  with which we  are
 acquainted.   Even had  they never been seen, the simple
 examination of the structure of the  stomach would lead
 us directly to the  inference  that it receives  an  additional
 supply of blood when engaged in digestion ; for the very
                            17* 
 198      GENERAL laws OF ORGANIC ACTIVITY.

 act of its distention by food renders the course of its blood-
 vessels less tortuous, and the flow of blood through them,
 consequently, more  easy and rapid.   In the case of the
 stomach, indeed,  the increased  circulation  is doubly re-
 quired ; not only as in other parts  to enable it to act with
 greater vigour, but also to supply the very copious secretion
 of gastric and  mucous fluids  necessary  for digestion, and
 which we have seen to commence the moment food touches
 the mucous  coat.   The quantity of gastric  juice actually
 secreted at each meal cannot easily be determined ;  but as
 more than an equal weight of it is required for the solution
 of food out of the  stomach, its amount must be very consi-
 derable.  Indeed we know that, on one  occasion when St.
 Martin  dined on  broiled mutton and bread without any
 liquids, the  gastric secretion was so  copious, that half an
 hour afterward the " stomach was as full of fluids as when
 he drank a pint immediately after eating ;"* and, as the
 whole of this  must  have been  derived directly from the
 blood circulating through the vessels  of  the  stomach, they
 must necessarily have received a very large supply to enable
 them to furnish it.
   It  is obvious, however, that the great  afflux of blood
 which takes place  toward the stomach and intestines during
 digestion, cannot occur without a  corresponding diminution
 in the quantity circulating on the surface and in other dis-
 tant parts of the body, attended, of course, with a diminished
 power of action in them.  Hence,  for some time after a
 full meal, there is  an inaptitude for vigorous thinking and
 bodily exertion, a depression of respiration, and, in delicate
 persons, a degree of  coldness or  chill felt  over the whole
 body.   But,  under ordinary circumstances, this depression
 is  not of long continuance.  After the requisite  secretions
 have  been provided  for  the  solution  of  the food and the
 formation of the chyle, a reaction  and  change in  the distri-
 bution of the blood, now partially renewed by the admixture
 of nutritive  chyle, ensue, and, by the stimulus which they
 afford, soon fit  the person for the  active resumption of his
 ordinary duties.
   That  this impaired activity of  the other functions after
 a full meal is natural, and intentionally  arranged by  the
 Creator, is plain, both from its universality among all kinds
 of animals and from  the mode in which it  is produced.
  * Beaumont's Experiments and Observations, &c, Edin., 1838,
p. 185. 
      QUIET REQUIRED BEFORE AND AFTER EATING.   199

Among the lower creatures the sluggishness  induced by
eating increases in proportion to the degree in  which they
gorge themselves with food.   The  boa constrictor, after a
plentiful repast,  slumbers for a week ;  and the glutton of
our own species, in similar circumstances,  drops into a
stertorous sleep of several hours.  If active exertion im-
mediately after a full meal be rendered  compulsory by any
external cause,  such as the presence of danger urging to
flight, the aliment  often  remains for hours in the stomach
undigested.  Again,  the very distention of the stomach
inseparable from a hearty  meal, necessarily impairs the
activity of several of the functions, by directly pressing upon
the vessels which supply their organs with  blood, and,
consequently, diminishing the stimulus essential  to  their
activity.
   The obvious  practical inference  to be deduced from a
consideration of the principle under discussion is, that rest
of body and tranquillity of mind  for  a  short time, both
before and  after eating, are necessary and  conducive to
healthy digestion.   If we have been engaged in severe and
fatiguing  bodily exertion just before sitting down to a meal,
digestion  is impaired in  two way3; and it would  be well
for dyspeptics to attend  to  the  fact.   The stomach  itself
participates directly in the general weakness caused by the
bodily fatigue ;  and, in the next place, the blood, which was
flowing copiously  through the vessels of the  muscles to
keep  up their unusual action, still  continues to do so,  be-
cause a sufficient interval  has  not elapsed to allow  the
excitement to subside and a new distribution to take place
toward the organs concerned in f digestion.   The conse-
quence is, that the stomach does not receive  blood  enough
to carry on its increased action, and furnish gastric juice
with  sufficient rapidity, or in sufficient quantity, to mix with
the whole of the food ; and that the  nervous energy, already
partially  exhausted  by  over-excitement in the  remoter
organs, is imperfectly supplied to the stomach, the tone and
action of  which are thus so far impaired as to render it no
longer  able to carry on  digestion with its usual  success.
Nearly the same result ensues when we have been engaged
in  anxious mental application  just before  eating; an»i,
accordingly, when we are fatigued with  mental or bodily
labour, we are naturally impelled to  seek repose  before
sitting down to table.   If we yield to this  instinctive 
300   PROPRIETY OF A SHORT REST BEFORE BATING

prompting, and refresh ourselves by a rest, we  not only
enjoy better what we eat, but also digest it with an ease and
comfort unattainable by swallowing our food the  moment
our labour is at an end ;  and hence the wisdom and advan-
tage of appropriating half an hour to any light occupation,
such as dressing, before sitting down to dinner.   If, how-
ever,  we  have  previously been engaged only  in very
moderate  exercise, or amusing  reading, an  interval of
repose is  not  required, because  then  there  is no  undue
excitement elsewhere to retard the necessary flow of blood
and nervous energy toward the internal organs.
  The practical  rule of avoiding  serious  exertion of mind
or body immediately after eating, which  is directly dedu-
cible from the physiological law  above explained, has long
been acted upon  in our treatment of the lower animals ; and
no one who sets  any value on the lives of his horses or dogs,
ever allows it to be disregarded with respect to them.  And
yet the same man who would unhesitatingly dismiss his
groom for feeding his  horse  immediately after a  fatiguing
chase or a gallop home, would probably think nothing of
walking into the house and ordering dinner to be instantly
served for himself  in  similar circumstances.   In  the army
the difficulty of managing recruits on a march, in this res-
pect, has often  been remarked.   Fatigued with  the day's
exertions, they are impatient for food, and, when they get it,
can scarcely refrain so long from devouring it as to admit of
its being even  moderately cooked.  They  consequently
labour under the double disadvantage of  eating before the
system  is in a sufficient  state of repose  to benefit by the
supply, and of having the food itself in a condition unfit for
easy digestion.   The  old campaigner, on the other hand,
instructed by former  experience,  restrains  his  appetite,
systematically kindles his fire, cooks his victuals, and makes
his arrangements for the night with a coolness of delibera-
tion which surprises the recruit;   and he is amply repaid for
his temporary self-denial,  by  the greater enjoyment  and
support which he derives  from   the very same  materials
which the impatience  of the  other  has  caused him in  a
great measure to waste.
   Let any one who doubts the advantages resulting from
attention  to this rule, consider for a moment its universal
and scrupulous observance by postmasters and jockeys, and
think whether these are persons likely to  throw away time 
ANIMALS INACTIVE AFTER EATING.        201
and trouble on a useless ceremony.  When a horse is taken
out of harness, an interval of repose is always allowed, that
the excitement of the system may have time to subside ; and
then not only an eager appetite  but an active digestion are
sure  to follow.   Many a valuable horse has been killed by
being prematurely fed after fatiguing exercise,  and man
himself  is no exception to the rule.   He not only enjoys a
meal with superior  relish, but digests it better, when due
repose has removed  the fatigue and excitement of exertion.
Even after continued activity of mind, a  period of tranquil-
lity or of gentle bodily exercise is eminently conducive to
the healthy action  of the  stomach, precisely because  it
favours  the new distribution of the circulating blood  which
that process requires.
   In accordance with this law of digestion, there is through-
out the whole animal creation  a marked aversion to acti-
vity for  some time after a full meal, although man, eager in
the pursuit  of  gain  or the gratification  of other passions,
often sets it at defiance, and engages in bodily or mental
labour both  immediately before and after  meals;  but, in
return,  he receives his reward  for  despising the authority
of Nature, in a severity of suffering from which the animals
which he treats so much better  than himself are by his care
entirely exempted.   Nowhere,  for example, does man hur-
ry off to business so immediately as  in the United  States
of America, and nowhere  does he bolt his food so much
as if running a race against time.   The consequence  is,
that nowhere do intemperate eating and dyspepsia prevail
to the same enormous amount.   Even in England, accord-
ing to Dr. Caldwell, the extent of transgression cannot be
compared wi(h what is witnessed among our Transatlantic
brethren ; and  the result shows, that if  we in Britian suf-
fer from indulging our fondness for good things, the com-
paratively deliberate way in which we set  about enjoying
them serves  as a partial safeguard, and exempts us from
a portion of the punishment which our brethren bring down
upon themselves by the hurry with which they first  devour
their food and then set off  to work.   Rapid eating  almost
invariably leads to overloading  the stomach ;  and when to
this  is added a total  disregard  of  the quietude  necessary
for digestion, what  can be  expected to  follow but  invete-
rate dyspepsia ?  Nowhere, accordingly, are indigestion
and  its  consequences so  universally met  with as  in  the 
202   LENGTH OF REPOSE REQUIRED AFTER EATING.

United States ; and from the latest accounts the evil seems
to be rather increasing than abating.
   The  reason why wounds,  blood-letting, bathing, and
other circumstances which tend to disturb the  regularity
of the circulation, are so hurtful after a full meal will now
be apparent.   The effect of wounds and blood-letting is to
give rise to  an  instantaneous  change in the distribution
of the blood, and to deprive  the  stomach of that which
is now  doubly required.  Bathing,  whether hot or cold,
has  an analogous effect ;  and  so,  indeed, have  all violent
and  sudden bodily or mental shocks.
   It must not,  however, be imagined that the  period  of
repose necessary to ensure healthy digestion extends over
the whole lime of the continuance of food in the stomach.
After a moderate meil, and in  ordinary health, the concen-
tration  of  the vital powers  in  that  organ, and  their pro-
portionate  depression in  other parts  of the  body,  rarely
continue, at least in a very marked  degree, beyond  the
period usually allotted to the siesta, or sleep  after dinner,
in warm climates and even in Italy and Spain—namely,
an hour or an hour  and a half.  When the meal has not
exceeded the bounds of moderation, a sufficient  quantity
of gastric juice for the digestion of the whole  is secreted
generally within the first hour ; after which  time, conse-
quently, the same quantity of blood  is no  longer  required
to be directed  toward the  stomach, but may beneficially
be distributed to such other  parts as, from their  activity,
more immediately require its aid.  If the muscular system
is to be  employed in labour or locomotion, the  blood  can
now be spared to sustain its activity ;  if the mind is to be
engaged in intellectual pursuits, it can now be sent  to the
brain without robbing the stomach.   The same principle,
of course,  applies to all the  other organs ;  and it is, there-
fore, chiefly during the first hour, till  all the gastric juice
be provided and  the chymification  of the food be fairly
commenced, that tranquillity of mind and inaction of body
are so assential.
   As already mentioned, the reality of increased circula-
tion in  the vessels  of  the stomach during digestion  has
been established by  ocular demonstration, as well  as  by
analogy.  The  increase in  the supply of nervous energy
which takes place at the same time is, however, scarcely
less certain, although, from  its nature, incapable of being 
      CONDITIONS FAVOURABLE TO NERVOUS ENERGY.   203

seen.  It is the almost characteristic feature of the  ner-
vous system to be excited by stimulus to increased action ;
and we formerly saw that, when the nerves of the stomach
are cut and the  flow of nervous influence  is arrested, di-
gestion instantly suffers.   But the same principle holds in
the nervous as in the  circulating system.  Energetic ac-
tion cannot be kept «p in two distant parts of the body at
the same time.   If the intellect be  intently occupied in
profound and absorbing thought, the  nervous energy will
be concentrated in the brain, and any demands made on
it by the stomach or muscles will be very imperfectly at-
tended to.   If, on the  other hand, the stomach be actively
engaged in digesting  a full meal, and  some  subject of
thought be then presented  to the mind, considerable  diffi-
culty will be felt in pursuing it, and most probably  both
thought  and digestion will be disturbed.  If the mental
effort required be easy and agreeable, and the meal  be  a
very temperate  one, there  will be much less difficulty in
simultaneously proceeding with both, because compara-
tively little nervous energy will then suffice for them.   Still,
however, each will go on more efficiently if not interfered
with by the other.
   When the  mind is active  and vigorous,  and properly
exercised in all its  departments of feeling and affection as
well  as of intellect, the nervous influence which the brain
produces is not only more abundant, but of a more healthful
and  invigorating quality.   Hence the well-known preser-
vative and restorative  influence of  cheerful dispositions
and gratified activity of mind, and hence the depressing,
morbid, and often fatal effects of corroding care, grief, and
apprehension, on every organ of the body.  Hence,  too,
the weak digestion and sallow complexions of literary  men
and hard students,  who suffer severely from  transgressing
this  law of the animal economy, by habitually engaging
in occupations requiring much exertion of  mind, not  only
soon after, but even during the very act of swallowing their
meals.   In this way many delicate persons suffer from the
peculiarly English practice of regularly reading the news-
paper during the act of eating breakfast.   Ignorant of the
connexion subsisting between the different functions  and
of their laws of action, such persons  cannot  be convinced
in time of the mischief they are doing, even  after its  ope-
ration has been explained to them.  In the conclusion, 
204   CONDITIONS FAVOURABLE TO NERVOUS ENERGY

however, experience teaches many  whose  reason is in-
sufficient for  their guidance, and  forces them to a closer
conformity with  the dictates of  nature, when obedience is
almost too late to be of benefit.
  The prodigious influence of the nervous  system on di-
gestion is familiarly and unequivocally exhibited in almost
every case of dyspepsia which each succeeding day brings
under the notice of the physician.   He knows well from ex-
perience that the diet may be selected with every care, its
quantity duly proportioned, and exercise rigidly practised,
and yet all his curative treatment fail even  to  relieve, un-
less his patient be at the same time freed from the pressure
of care, and due attention be devoted to the observance of
mental and bodily repose after every meal.
  The heavier the meal, the greater is the desire for abso-
lute rest, and the less advantageously can active exertion be
encountered.  When the  stomach is loaded, the whole vital
energies seem to be concentrated in it to enable it  to cope
with  the task imposed npon it.   But when we eat tempe-
rately, there  is less  necessity for entire quietude of  mind
and body.  Accordingly, if we  do not experience the  same
dislike to  exertion after a light forenoon lunch which we
do after a heavy late dinner, the reason is simply, that less
blood and gastric juice, less nervous energy, and less  vigo-
rous action in the stomach are required to  digest in the one
case than in  the other.
  Among  operative manufacturers, who are much within
doors, and who are allowed only  a few minutes for meals,
indigestion is very prevalent.  Ordinary labourers are better
treated in this respect, as they are allowed one hour for
breakfast  and another for dinner.  To most of  them the
walk to and from their own houses is almost as good  as, if
not better  than, absolute rest, because it varies their  posi-
tion, is taken leisurely, and costs no effort.
  Those who are compelled by circumstances to active exer-
tion immediately after a meal, or  whose minds are intently
occupied in thought or emotion, will find their only safety in
eating less than when  differently situated.  The  stomach,
having less labour imposed upon  it, will require less blood
and  less nervous  energy, and, consequently, less of both
will be abstracted from the other organs which are also in
activity, and requiring their assistance.  Travellers, literati,
and other actively engaged men, know this rule by  experi- 
    STATE OF MIND VERY INFLUENTIAL ON DIGESTION. 205

ence, and some of them have specially noticed its  impor-
tance.   Richard Cumberland, for example, in speaking of
his own habits, says :  " Nature has given me the hereditary
blessing of  a constitutional and habitual temperance, that
revolts against excess of any sort, and never suffers appetite
to load the  frame.  I am,  accordingly, as fit to resume my
book or  my pen the instant after my meal as I was in the
freshest  hours  of the morning."*  This  compatibility  of
temperate eating with activity did not escape the acute ob-
servation of Hippocrates.
   The state of the mind, indeed, exerts a powerful influence,
not only on  the stomach, but on the whole process of nutri-
tion, and greatly modifies the  quantity which may be safely
eaten.   If  the mind be gay and  joyous, appetite will  be
comparatively keen, digestion effective and  rapid, and nu-
trition complete.  Examples of this  kind  abound in child-
hood,  and  among an  easy-minded, well-fed  peasantry ;
whereas, if the mind be harassed  by care and anxiety, or
devoured by grief, envy, jealousy, or other troublesome and
disquieting  passions, the healthy calls of appetite will  be
scarcely known, and digestion and nutrition will be  equally
impaired ;  for it is literally true that " indigestion, or, to use
the term of the day, a  Bilious attack, as often arises from
over-exertion or anxiety of mind, as from refractory food."t
This fact is exemplified on a  large scale in every commer-
cial country, and especially in times  of public distress and
political  change.   Shakspeare obviously had the principle
in view when he made  Caesar exclaim—

     " Let me have men about me that axe fat,
       Sleek-headed men, and such as sleep o' nights.
       Yond' Cassius has a lean  and hungry look ;
       He thinks too much : such men are dangerous.
         Antony.   Fear him not, Caesar, he's not dangerous;
       He is a noble Roman, and well given.
         Ctesar. Would he were fatter: but I fear him not:
       Tet if my name were liable to fear,
       I do not  know the man I should avoid
       So soon as that spare, Cassius.  He reads much.
       He is a great observer, and he looks
       Quite through the deeds of men ;  he lories no plays,
       As thou  dost, Antony ; he hears no music,
       Seldom he smiles, and smiles in such a sort
       As if he mocked himself, and scorned his spirit

            ♦Cumberland's Memoirs, vol. ii., p. 204.
            t Art of Invigorating Life, 3d. ed., pi. 73.
                           18 
206 ACTION OF MIND ON DIGESTION TO BE ATTENDED TO.

       That could be moved to smile at anything.
       Such men as he be never at heart's easo
       While they behold a greater than themselves,
       And, therefore, are they very dangerous."

   Even experience must have taught every one with what
zest we sit down to enjoy the pleasures of the table, and how
largely we incline to eat, when the mind  is free, unburden-
ed, and joyous, compared with the little attention we bestow
on our meals  when  we are overwhelmed with anxiety, or
have the whole energies of the mind concentrated on some
important scheme.   There cannot be a doubt, indeed, that
the over-exertion and excitement, or absolute inertness, of
mind, in which sedentary people are generally immersed,
contributes greatly,  along with  the want of muscular ex-
ercise in  the open air, to impair the tone-of the digestive
organs.   In this way, as it is not less justly than forcibly
remarked by Dr.  Caldwell, " dyspepsia commences perhaps
as often in the brain as in the stomach.   Possibly oftener.
That this is true of the disease  in Europe will scarcely be
denied, after a fair examination of the facts connected with
it.  It is there almost  exclusively a complaint of the stu-
dious and the  scheming, who, over-tasking their brains, in-
jure them by  toil.   Among  the husbandmen of England,
who steadily pursue their tranquil mode of life, regardless
of the fluctuations of stock, the bickerings of party, the fate
of political measures, and the changes of place, dyspepsia
is almost a stranger."   "  In the cities  the  same is, in a
great measure, true of merchants, manufacturers, and me-
chanics, who are engaged in a regular and well-established
business, which is fully understood by them, where the risk
is slight  and the  profits sure, and  no disquieting anxiety
attends it.  Such individuals have a good digestion, and
bear the marks of it.   But with literary men, officers  of
state, dealers in scrip, daring  adventurers, and anxious and
ambitious projectors of improvements, with these and every
other  brain-worn class of  persons, the case  is different.
Dyspepsia is their torment, and they exhibit deep traces of
it in their lean  frames and haggard countenances.  Yet are
they much more select in their diet, both a3 respects quan-
tity, quality, and cooking, than  the classes to whom dys-
pepsia is  unknown.   This fact is notorious, and has been
so for centuries.  Nor tin it be attributed, I think, to any
other cause but excessive and deleterious cerebral irritation 
REPOSE AFTER MEALS.
207
 in  the one case, and an exemption from  it in the other ;
 and this cause seems sufficient to solve the problem."*
   In denouncing active exertion  of mind  or body  immedi-
 ately after eating as inimical to digestion, it  is not meant
 that we  should go to sleep or indulge in absolute  listless-
 ness.  A weak constitution may require something like
 complete repose, but a person in ordinary health may in-
 dulge in a ieisurely saunter or pleasant  conversation not
 only without injury but with positive benefit ;  and  perhaps
 there is no situation in which digestion goes on so favour-
 ably as during the cheerful play of sentiment  in the after-
 dinner small-talk of a well-assorted circle   The  nervous
 stimulus sent to the stomach is then of the most healthful
 and invigorating description, and  even the dyspeptic, if on
 his guard against a heavy meal, forgets his woes amid the
 unwonted vigour of  his functions.
   It is true that thousands who habitually neglect the ob-
 servance of the condition here adverted to, continue to live
 and digest for years  without appearing to suffer much from
 their conduct.   But it is not less true that there are many
 more who bring wretchedness and disease  upon themselves
 and their offspring in the  vain attempt to counteract the
 intentions of Nature, and that there are comparatively few
 even of  the former so happily constituted  as to escape en-'
 tirely unscathed.   Most frequently the evil consequences
are only  accumulating, and when  they are summed up at
the end  of years, the victim finds himself more  severely
punished than he had ever expected to be.   In this respect
the consequence resembles that arising from breathing in  a
vitiated  atmosphere.  The  effect may not be perceptible
for a lime ;  but if God has ordained a pure air to be best
adapted  for respiration, we have the infallible  authority of
His  omniscience  for believing  that one which is  vitiated
must be  less wholesome, although His beneficence has so
constituted us, that  the injury resulting from  it is  gradual
in its infliction, for the  very purpose of giving us time to
escape.   In like manner, if bodily and mental relaxation
are favourable to digestion, we have  the  same infallible
guaranty that every departure from them must be in so far
hurtful, however slowly the effect may develope itself.

      * Caldwell's Thoughts on Physical Education, p. 94. 
208
                    CHAPTER IV.
   THE DIFFERENT KINDS OF CONSTITUTION AND OF FOOD
      CONSIDERED WITH RELATION'  TO EACH OTHER.
Man remarkable for the variety of his food ; advantages of this —
  Man not guided by instinct to the choice of his food, but by ob-
  servation and experience ; his welfare thus intrusted to himself
  —Principle on which fitness  of food ought to be determined ; in-
  formation still much wanted—Nature of constitution to be con-
  sidered—Varieties bf constitution or temperament; the lymphatic,
  nervous, sanguine, bilious, and mixed temperaments—Diet ought
  to be modified according to temperament; illustrations—Different
  kinds of food ; their classification and division into  animal and
  vegetable—Londe's propositions regarding their relative digesti-
  bility—Animal food and its varieties ; its chemical composition no
  test of its dietetic qualities—Division  into fibrinous, gelatinous,
  and albuminous meats—Adaptation of each of these to different
  temperaments, ages, and states of health—Vegetable aliments and
  their properties ; principal divisions of them, and general remarks
  on their use and adaptation.
   The next subject  which  presents itself  for examination
is the kind of food best adapted for the  support and nourish-
ment of man.
   Man, considered as an organized  being, is almost as re-
markable for the great variety of substances which he ren-
ders subservient to his own  support, and the great variety of
ways in which he prepares  them for his use, as, considered
in his mental constitution, he is remarkable for the number
and nature of his moral and intellectual endowments.   In
the  former respect, indeed, he forms as great a contrast
with many of the lower animals as he does in the  latter.
Under the  guidance of a  special instinct, most animals
select at once that kind of food which Nature has destined
for their use, and abide by it through life with a constancy
which dreams not of change.  Man,  on the other  hand,
impelled by the love of variety, not only exerts his ingenuity
to the uttermost to give new forms  to  his food  by means
of cookery, but  ransacks  every  quarter of  the  habitable
globe, and lays earth,  sea, and air under  contribution for
the supply of his table  and  the gratification of  his palate.
  This difference in the mode of action of the instinct for
food in man and  animals bears a direct relation to the cir-
cumstances in which  he and they are respectively intended
to exist.  As a general rule,  the lower animals are restricted
to a comparatively limited locality or climate, and the whole
course of their lives runs on  in one almost unvarying round.
They consequently neither require nor seek for any unusual 
           RELATION OF FOOD TO CONSTITUTION.       209

change of diet, except under the pressure of actual want.
With  man, however, the case is widely different.   He is
often called  upon to quit the country of his birth, and to
expose himself to such vicissitudes, even when livino- under
the same climate, as would render continued existence im-
possible, if he also were restricted to uniformity of diet.   In
him, consequently,  appetite is not  an instinct which  points
unerringly to the proper objects of its own gratification.  It
is a blind impulse which can be safely guided only by the
aid of knowledge and  reflection.  Without these to direct
us in our choice of food, surrounded as we are by many
substances endowed with the most opposite qualities, and
the external appearance of which affords no clear indication
of their wholesomeness or insalubrity, we would stand in
the midst of creation far more defenceless than any of the
inferior  animals, and would frequently perish  poisoned by
our own ignorance, where, under our present constitution,
it is easy for us to  find both  safety and support.   It is for
ourselves, then, to decide whether we will earn health and
comfort by making ourselves acquainted with  the proper-
ties of the different kinds of food, and  conforming  to the
principles by which their use ought to be regulated, or risk
the loss of both by indolently  giving  ourselves up  to the
blind guidance of appetite, and eating whatever comes in
our way.  I need  not waste argument to show that the
former alternative is that which will recommend itself to
every reasonable being.
   In judging of  the fitness of any aliment as an article of
diet, we must not rest  satisfied with inquiring into its own
properties alone.   It is essential also to take into account
the nature of the living and organized system upon which it
is to act, and the relation in which these stand to each other.
The bodily constitution differs so widely indifferent persons,
that the food which is  appropriate in one instance  may be
very much the reverse in another.  Even at different ages
and under different circumstances of health and occupation,
the same food which formerly proved salubrious, may now
prove detrimental to the  very same individual.   The true
philosophy of diet,  then, I cannot refrain from repeating,
consists far less,in an abstract acquaintance with the pro-
perties of different alimentary substances, than in the power
of accurately  adapting  the kind of food to the peculiarities
of the individual constitution at the lime it is administered.
                          18* 
210        GENERAL VIEW OF THE DIFFERENT
Viewing the latter, consequently, as the great object to bo
attained, we shall  offer a few remarks, first, on the nature
and varieties of  the human constitution ;  secondly, on the
different kinds of food and their distinguishing properties ;
and, thirdly,  on  the principles which ought to guide us in
attempting to adapt the one to  the other.   To do full jus-
tice to these topics would  require an extent of detail incom-
patible  with  the limits  of a work like this,  and  also  an
extent of knowledge  which as yet does  not  exist.   But,
notwithstanding my inability to treat them in the way their
importance deserves, I think  it better broadly to avow that
inability, and direct the  attention of others to the means of
increasing  our knowledge, than to conceal  the deficiency
by passing it over in silence.  It is  true that we cannot
hope ever to obtain rules  of conduct  strictly and minutely
applicable to every individual,  because to do  so would  re-
quire us to investigate the action of every variety of food
upon every form of constitution  under every possible variety
of circumstances—a proceeding obviously beyond the limits
of the human powers. But for practical purposes, fortunate-
ly, do such extreme minuteness of research is required, and
we may safely rest satisfied with  a knowledge of principles
far less difficult of discovery, and, at the same time, easily
applicable, by the  aid of reflection, to all the ordinary va-
rieties and conditions of man.
  Principal varieties of the human constitution.   On ex-
amining the structure and .mode of action of the  human
body in different individuals and at different ages, remarka-
ble  differences  are observable  in the relative proportions
which the various organs and functions bear to each other,
and to the system of which they form a part.   In one-indi-
vidual the head  and nervous system predominate over the
rest of the organization, and impart to the whole a character
of unusual sensibility.    In  another  the nervous  system
appears  feebly  developed, and  the body presents  the soft
rounded form and  slow  heavy action arising from the pre-
dominance of the  lymphatic  vessels ; while in a third the
muscular or sanguineous organs are in powerful proportion,
and impart a vigorous and enduring energy to all the bodily
functions.   Strictly speaking, every person possesses a con-
stitution peculiar to himself, and arising out of the peculiar
relation which the different  parts of his organization bear
to each other.   But, speaking in  a more general sense, we 
CONSTITUTIONS OR TEMPERAMENTS.       211
meet with many constitutions which resemble each other so
much in their essential features, that, for all practical pur-
poses,  they may be  advantageously grouped together  and
considered  as identical.  Tn this sense four great  class-
es of constitutions  or temperaments may be described as
primary or fundamental;  because, according to the propor-
tions in which they  are combined  in  any individual,  all
the others  may be  compounded from  them.  These four
primary temperaments are, 1st, the lymphatic ; 2d, the ner-
vous;  3d, the sanguine; and, 4th, the  bilious.  The tem-
peraments arising from the combination of two or more of
these are termed the mixed or  compound  temperaments,
and they derive their distinctive names  from those of their
constituent elements. Thus, a predominace of the nervous
and lymphatic elements  constitutes  the nervous-lymphatic
temperament; a mixture of the sanguine  and nervous, the
sanguine-nervous; or a mixture of the sanguine and bilious,
the sanguine-bilious temperament, and  so on, always plac-
ing first in  order the name of the temperament which ap-
pears to be in the ascendant.
  The lymphatic temperament is distinguished by the pre-
dominance of the white vessels or lymphatic system, the full
rounded heavy  form, fine transparent skin, soft hair, imper-
fectly formed blood, languid circulation and expression, flac-
cid and feeble muscles, and general  inactivity of mind and
body.  The nutritive functions predominate in activity over
all the  others, and hence the increasing tendency to indo-
lent inaction which is the natural concomitant of stoutness
arising from full living, and which is seen in  perfection in
the torpor or hybernatmg animals on the  approach of winter.
In infancy and childhood, when rapid nutrition is required,
the lymphatic temperament is well marked ; but at that age
it is modified in many of its features by the activity of the
nervous system.  As a general rule, also, it is more preva-
lent  in women  than  in men, and hence  one cause of  the
greater addiction of the  former to sedentary pursuits.
  From the inferior  activity accompanying the lymphatic
temperament, individuals in whom it predominates are unfit
for  continued or severe  exertion, and,  when roused by a
strong stimulus, their excitability is soon exhausted.   The
habitual tendency is to indolent inaction, or  the dolce far
niente.   As a natural consequence, the peculiarities of this
temperament are aggravated by a sloppy, soft, and unstin.u- 
212 NERVOUS, SANGUINE, AND BILIOUS TEMPERAMENTS.

lating  diet,  and diminished  by the use of  concentrated,
nourishing, and rather stimulating food.
   The nervous temperament is characterized by the pre-
dominance of the brain and  nerves, and, consequently, by
high nervous sensibility or excitability.  It is most remar-
kable in  females of the higher ranks and abounds most in
highly civilized communities.  It is distinguished by deli-
cacy of fibre, fine thin skin,  sharp expressive features, fine
hair, susceptibility of external impressions, and high activity
soon wearing itself out.  Hence vivacity  alternating with
depression and a tendency to extremes.   In children  the
nervous temperament is also well marked, but in them, as
in women, its influence is generally modified by  a mixture
of tho lymphatic  constitution.  The  late  hours, heated
rooms, and numerous excitements of modern society assist
greatly in the production and aggravation  of the evils con-
sequent on  an  excess of the nervous  temperament.   To
correct this tendency, a mild and plain but nourishing diet,
a tranquil mode of life, regular but not excessive occupation
of mind and  body, ample exercise in \he  open air, and
bathing are highly useful.
   The sanguine temperament is indicated  by the predomi-
nance of the apparatus of sanguification, the large capacity
of the chest, the volume and susceptibility of the heart, the
abundance and  richness of the blood, and great  develope-
ment of the bloodvessels, a fine skin, fine light or reddish
hair, florid complexion, and elastic activity of mind and body.
Under the use of stimulants and exciting food this activity
is  apt to  pass into  inflammatory  action, and hence a mild
and unexciting diet is the most appropriate.
   The bilious temperament is that in which the biliary and
muscular functions  seem  to predominate,  and is indicated
by a dark yellow or brownish complexion, short, datk, crisp
hair, a dry lean habit of body, well defined and firm muscles,
prominent veins, a dry, brown, rather coarse skin, expres-
sive dark  eyes, and general energy of constitution.   The
characteristic feature of this temperament  is that of endur-
ing activity, not passing  so easily into excitement as the
nervous,  nor yet so easily exhausted as the sanguine.
   Such are what may be called the primary temperaments ;
but the varieties arising out of their admixture in different
proportions are very numerous.   Thus, from the combina-
tion of the lymphatic and sanguine, a temperament is  de- 
RELATION OF FOOD TO TEMPERAMENT.      213
rived which participates in the qualities of both, and which
is very common in childhood and in women.  In like man-
ner, the bilious may be combined  with  the nervous,  and
produce a mixed temperament, characterized  by a keener
sensibility than the pure bilious, and a more sustained  and
energetic activity than the pure nervous.   In the same way
other modifications of temperament may be formed ;  but
for a more full explanation of them, I must refer the reader
to any of the standard works on physiology.
   Such being  the great  variety of constitutions among
mankind, and so strikingly different being, in  many of them,
the predominant properties by which they are respectively
characterized, the  reader will at once perceive that the kind
of diet  which is suitable for one person may prove very
unsuitable for another of a dissimilar temperament; and
hence, when laying down dietetic rules, the necessity already
referred to of attending, not only to the qualities of the food
itself, but to those of the constitution for which it is recom-
mended.
   When the original temperament is of a strongly marked
kind, the influence of diet and of external circumstances in
modifying it is very limited ;  and then our chief aim ought
to be to adapt the mode of life to  the peculiarities by which
it is distinguished.   For example, if a youth possesses  the
characteristic features of an energetic bilious and sanguine
temperament, prudence recommends that we should enjoin
moderation in the use of stimulants, and place him in a pro-
fession  affording ample scope for mental  and  muscular
activity.  If we neglect these indications, and engage him
in purely sedentary pursuits, and  allow him  a free and  ge-
nerous  diet, his health will soon fail, and he will sigh in
misery for liberty and activity.  If, on the other hand, we
restrict a slow lymphatic youth to a very mild and soft diet,
and  place  him  in  a situation requiring promptitude and
energy of action and an ever-wakeful attention, he also will
suffer ;  because the plain and unstimulating food which is
very appropriate for a person of a highly excitable tempera-
ment, will depress still farther his already feeble energies,
and prove insufficient for the support of his  health.  If,
again, a stimulating regimen be pursued by  a person of an
already  excitable temperament, the high natural activity will
probably be carried so far as sooner or later to induce disease.
Hence it is indispensable, especially in the proper training 
214      THE KIND OF FOOD OUGHT ALWAYS TO

of the young, that due regard be paid to the adaptation of
the diet to the peculiarities of individual constitutions from
the earliest period of life.
   When the temperament is of a mixed kind, the influence.
of regimen and education in modifying the original constitu-
tion is much greater, and, consequently,  much may be done,
by judicious treatment, to remedy defects or improve what
is gopd.   This is especially the case when, in the measures
we adopt, we take advantage of the natural modifications
of temperament which take place, to a greater or less extent,
as growth and life  advance.  During  the  transition from
infancy to childhood,  for example, the temperament which
was at first almost purely lymphatic, and  marked by the
predominance of the nutritive functions, and a tendency to
almost constant  sleep, becomes gradually more  and  more
nervous as the feelings  and  general  sensibility awaken to
activity.   At a later stage, again, the temperament becomes
modified  by the  increasing developement of the  organs of
sanguification, as evidenced by the  enlarged  capacity of
the heart, lungs,  and  chest; and, in accordance with this
change,  the nervous  sensibility becomes  less acute, the
desire for bodily activity increases, until,  with many,  it
becomes almost a passion.   When growth is fairly  com-
pleted, and active nutrition  and abundance of rich blood
are less urgently required, the steady and enduring activity
of the bilious temperament comes proportionally more into
play,  and is more appropriate to the increasing gravity of
the duties which then  occupy the mind.   Accordingly, it is
only in mature age that  its principal features are found in
their,most marked form.  In each of  these stages some
modification of diet is  required, if we wish to aid the efforts
of nature and to obain the highest degree of health and effi-
ciency; of which  the constitution is susceptible.   As yet,
however, little attention has been paid to this subject, and
much remains to be ascertained with regard to it.
  In adapting the mode of living to particular constitutions,
it will be of  great assistance to us to have a clear percep-
tion of the precise  object we wish to attain, and  know
whether we  should  develope or repress the predominant
temperament.  For example, if a child be characterized  by
a highly lymphatic temperament, we  can be at no loss to
determine that every  effort  should be made to repress its
predominance, and to  increase the proportion of the san« 
           BE ADAPTED TO THE TEMPERAMENT.        215

guine, bilious, and nervous elements.   With this view a dry,
airy locality, with a good exposure, should be selected, and,
instead of slops, broths, and bulky food being recommended,
the diet should be  composed  chiefly of concentrated and
moderately  stimulating  aliments, such  as  beef, mutton,
curries, spices, coffee, &c,  given in moderate  quantity
and at proper intervals.   If. however, the person be of a
purely nervous temperament, the same course of manage-
ment  would be highly injudicious, as it would increase the
tendencies  which are already in excess.  In this latter case
mild nourishment and the avoidance of excitement would
be the most appropriate.  In constitutions of a mixed kind,
again, the best regimen  is that which includes sufficient
variety to sustain the respective functions in due and pro-
portionate activity.   But if from any cause it be considered
desirable to cherish any individual element of a mixed tem-
perament more than another, the regimen ought,  of course,
to be modified to meet that exigency.
   If we now inquire how far the  diet of the young is re-
gulated in families  by a reference  to peculiarities of con-
stitution, we  shall find that no such thing is thought of by
parents, except during sickness ;" and that children of every
age and temperament are brought up  on precisely the same
kind of food; or, if any difference be made, it consists in
the liberty sometimes granted to a  child to eat more or less
of any particular dish, according as  taste or caprice  may
direct its choice.   And yet there is abundant evidence to
show, that great and permanent good or evil may  be effect-
ed according to the fitness or unfitness of the diet to which
the individual is thus accidentally  subjected,.  At another
time I hope to be  able to return to this branch of the sub-
ject with more advantage to the reader; but at present I
must  pass on to  the consideration of the different kinds of
food which are used for the nourishment of  man.
   The different  kinds of food may be classified  according
either to their elementary composition, as  ascertained by
chemical analysis, or to their general properties, as ascer-
tained by observation.   In the present state of our know-
ledge the "latter is  the only ground of classification which
can be of any practical use in the regulation of diet, and
is, consequently, that which we shall prefer.
   With the exception of air and water, no substance which
is not itself  organized, or, in  other words, which has not 
 216    CHANGES ON ANIMAL AND VEGETABLE FOOD

 already constituted a part of some animal or vegetable, can
 be used as food, or serve for the nourishment of man.  Even
 the various earths and salts which enter into our composi-
 tion, ana  which are not found in water or air, are derived
 exclusively from the other organized substances which we
 consume in the form of food.   The first great division  of
 aliments, therefore, is  into animal and vegetable ; but before
 treating of the respective properties of each in their relation
 to the  human system, it will be useful to make a few ad-
 ditional remarks on the comparative readiness with which
 they are acted upon in their progress  through the stomach
 and intestinal canal.
   From the experiments of Dr. Beaumont, already so often
 referred to, it appears that animal and vegetable aliments
 are very differently acted upon by the digestive organs  of
 man.   Animal food, subjected to the influence of the gastric
 juice, becomes so entirely  converted into chyme as to pre-
 sent no trace of its original organization on its expulsion
 from the stomach ; but with vegetable aliments it is other-
 wise.  On their  expulsion from the  stomach they are,  in
 general, found to be only partially changed, and to retain
 some trace at least of their distinguishing structure, which,
 indeed, they often do not lose entirely till they have advanced
 a considerable way in their progress through the intestinal
 canal, and there undergone what may with propriety be call-
 ed the  completing process  of intestinal digestion.
   Instances are very rare, indeed, in which, as in St. Martin,
 the process of healthy stomach digestion is laid open to our
view ;  but those in which  some of the changes produced
in the food as it passes through the intestinal canal may be
examined  are less  unfrequent.  Obstructions occasionally
occur in different parts of the intestines themselves, which,
from interrupting the passage of their contents, would prove
speedily fatal, if Nature did  not in some instances  avert
the danger by forming a new and  direct outlet, by means
 of which the residue of the food continues to escape through
 the coats  of the bowel  to the external surface, either for
 the remainder of life or till the natural channel be restored.
 As these openings into the  gut occur sometimes  higher up
 and at  other  times lower down, it is  obvious  that a good
 deal of information may be obtained by  observing and  com-
 paring the different appearances which the intestinal  con-
 tents present on their escape, according to the portion of 
             IN THE STOMACH AND BOWELS.          217

the bowel in which the opening is  situated.   M. Londe,
the well-known writer on Hygiene, has availed himself more
extensively and carefully of the occurrence of such oppor-
tunities of increasing our knowledge than any other observer
with whom I am acquainted, and, therefore, it will be not less
an act of justice to him than  advantageous to the reader,
to direct attention  to his results.  M. Londe's "Conclusions,
indepd, may be relied upon  with  considerable  confidence,
as their accuracy is confirmed, not only by their accordance
with  Dr. Beaumont's observations,  but by the direct and
concurrent testimony of Professor Lallemand, of Montpel-      \
lier, and  Mons.  Bouillaud, of Paris, who also investigated the
subject with care and success.  The propositiens in which
M. Londe has imbodied his  results (already briefly referred
to at p.  151) are as follows  :
   " 1st, Animal food appeases hunger more completely, and
for a longer time, than vegetable food.   This fact has been
observed in all  times and places, and no proofs are required
to substantiate its truth."
   " Idly, Animal substances are better fitted for being acted
upon by the digestive organs than  vegetable aliments ; or,
in other  words, they are better calculated than vegetables
to excite the assimilating powers of the stomach.  The fol-
lowing is a  proof:  The residue which one of my patients,
Madame Laf****, evacuated by the artificial opening of the
bowel was  such, when  she  had eaten chicken or cutlets,
that it was impossible for me to find in it anything analogous
to the original substance.  On the contrary, when Madame
Laf**** had eaten spinage, herb soup, or rich soup with
carrots, I recognised the  different vegetables, on their escape
by the opening, so essentially unaltered, that both the pa-
tient  and myself could easily distinguish the  spinage from
the other herbs which the soup contained.   Comparative
anatomy, indeed,  seems to confirm this proposition, as
Nature  has multiplied  and  enlarged the digestive organs
of herbivorous  far  beyond those of carnivorous  animals.
This  fact alone ought to have excited a suspicion that the
leguminous vegetables are converted into chyle with greater
difficulty, and are more  refractory to the  digestive organs,
than animal food."
  " Zdly, Animal substances remain longer in the digestive
tube than vegetables.  Tbe  proof is, that, in my patients,
salads, prunes,  apples, and spinage always appeared at the
                           19 
 2'IST    CHANGES ON ANIMAL AND VEGETABLE FOOD

 wound at the end of an hour, while the animal food irevew
 reached it in  less than three hours."  At first sight the
 reader may imagine the second and  third propositions to
 be at variance, but they are not so in  reality.  Vegetable
 substances leave the stomach sooner than animal, but then
 they leave it  only imperfectly digested.   Animal  food re-
 mains longer on the stomach, but it  leaves it completely
 converted into chyme.
   " 4ithly, Both animal and vegetable aliments  remain in
 the digestive tube longer in proportion as they contain more
 nutritive juices, and as the state of that tube enables it to
 extract a larger quantity of these juices.   The proof is the
 fact just mentioned, that animal aliments remain longer than
 vegetable.   Other proofs  are, that several tjimes  I  gave
 Madame Laf**** a portion of vermicelli, with water and
 butter, and also panada ; neither of which ever arrived at
 the wound in  less than  two hours, and then in a state not
 recognisable.   We have seen, however,  that prunes and
 salads appeared at the end of one hour, very little changed,
 and that hunger soon returned1.  Again, the residue of boiled
 beef arrived at the external  opening sooner than that of
 meat done on the gridiron.  Another  fact is, that during
 five days I prescribed to one of my patients, at each meal,
 either a beefsteak, a cutlet, or the wing of a fowl, but always
 added either  prunes, spinage, or salad.  In this case the
 vegetable matter uniformly made  its  exit about an hour
 after, while the animal food remained,  and, after undergo-
 ing a  complete change,  was expelled by the natural outlet.
 The same thing occurred when fat carrot-soup was given.
 The carrots alone appeared at the wound, while the animal
 soup and the bread remained in the intestine.  It seems as
if  the digestive canal, anxious to get rid of the vegetables,
from  which it could extract  nothing, and constantly con-
 tracting to drive them away, took the opportunity which the
 accidental hole afforded of expelling them altogether ; while
it retained, by a sort of predilection or elective attraction,
the animal matter which could repay the expense of its
labour."   Precisely similar  results  were obtained by Dr.
Beaumont in his experiments on the relative digestibility
of animal and vegetable food in the stomach of St. Martin.
   " blhly, It is probable that the use of  aliments 'which are
not easily assimilated developes the power of the muscular
coat of the stomach, as it contracts incessantly to transmit 
             IN THE STOMACH AND BOWELS,          218

4hem to the intestine ; and it is probable-that the same class
<}f aliments leaves the mucous coat in a state of inaction.
On the contrary, the use of a diet composed chiefly of sub-
stances in.which the nutritive principles are  very concen-
trated, excites strongly the action of the mucous membrane,
and gives little scope,to the muscular coat.  These results,
however, are only inferential, and cannot be the subjects
of observation."
  " 6th, With regard to the influence which the cohesion of
alimentary substances has on their manner of acting, I have
observed that, the quantity of nutritive juices being equal,
the aliment which has least cohesion traverses the digestive
canal most rapidly.  In  proof of  this,  I have frequently
given, by  spoonfuls, eggs imperfectly boiled, and without
bread, to  the patients above referred to, and the  residue
was  evacuated  by the wound in one hour and three-quar-
ters  after the eggs were  eaten.  Hard-boiled eggs,  on the
contrary, were always much longer of arriving at the orifice.
When, on the other hand, any two aliments contained  very
unequal  proportions of nutritive  matter,  the  influence of
cohesion becomes scarcely perceptible, and  that which is
most nutritive remains longest in the digestive canal, even
when its cohesion is  very  small.  For example, when
stewed or raw fruits, or  boiled vegetables, such as carrots
or turnips, were given, they arrived at  the orifice  in one
hour ; whereas the residue of strong  concentrated soup,
in which there  was no cohesion, did not reach it till two
hours, or nearly three,hours when bread was  added."
   " 1th,  The alteration which  the food undergoes  in the
alimentary canal  also bears a relation to the  wants of the
other organs, a fact which requires to  be kept in mind,
otherwise the results obtained will occasionally seem to be
opposed  to those  already enounced.   For example,  after
having subjected one cf  my patients for several days to  a
strict and  severe  regimen, 1 gave him various  vegetable
aiiments in small quantity, and all of thens appeared greatly
altered.   I gave  even a  salad  a la scarole without bread,
and  in one hour afterward a yellow residue of a creamy
consistence began to flow from the wound, but not a trace-
of the salad  could be detected in it.   As this experiment
was one of the first which I made, I concluded, contrary
to the opinion of M. Lallemand, that herbaceous vegetables
Are  entirely changed  by the digestive organs; but I  had 
220  CHANGES ON ANIMAL AND VEGETABLE FOOD, ETC.

soon occasion to recognise both my own error and the accu-
racy of the results presented by that admirable observer."
  " 8/A, When the wants of the organization are not urgent,
the digestion or alteration of substances which are difficult
of assimilation, such as carrots, fruits, leeks, and many other
vegetable aliments, commences only  in the Hewn.   I have
always found these  substances  resist the action of  the
gastric juice and mucous secretions, as well as that of the
pancreatic and biliary secretions:"   When, however,  the
system is really  in  want  of  nourishment,  digestion,  as
already noticed, begins sooner and proceeds faster.
  " 9th, Cookery acts by diminishing the cohesion of some
kinds of food and increasing that of others.   It acts also
in modifying their smell and taste, which might  otherwise
prove repugnant  to  the stomach and paralyze its action.
Cookery also deprives some aliments of certain soluble bit-
ter, acrid, or poisonous properties, which might be injurious
to the stomach and even to life. With respect to the stimu-
lating or sedative properties which cookery imparts to food,
it may be remarked that, when stimulants are added,  diges-
tion is more  rapid, and a new vigour is more quickly diffused
through all the body.   When sedative properties are given
to the food, it mav either  not stimulate sufficiently to be
digested at all, or, 'if it is digested, it may lower the tone of
all the functions.  In general, the  least  cooked aliments
are those which precipitate vital action the least."
  " \0th,  The spontaneous  alteration which  alimentary
substances undergo is, within due limits, a very efficacious
means of increasing their digestibility,  but it renders them
at the same time  somewhat less nutritive.  This sponta-
neous alteration acts in two ways.   It first very evidently
disunites their principles and impairs  their cohesion,  and
afterward developes  stimulant properties in the nutritive
matter.  It  is on  this principle that, to render  meat tender
and digestible, we allow it to undergo the first stage toward
decomposition.  For  the same reason, we allow bread to
ferment.  In like manner,to rendercheese more stimulating,
and to convert it into a digestive seasoning, we allow it to
acquire a high degree of alcalescence."*  The digestibility
of many kinds of food is thus increased, but their nutritive
power is at  the same  time  diminished.
   I have already mentioned, that,  in  the present state of our
  * Londe, Nouveaux Elemens D'Hygjene* 2d edit.* voL ii., p. 3& 
          CTHEMICAL ELEMENTS OF ANIMAL FOOD.      221

knowledge,  we can derive little dietetic aid from any clas-
sification based on the chemical composition of alimentary
substances.   All the varieties of animal food, for example,
are composed of different proportions of the same chemical
elements, viz., carbon, hydrogen, oxygen,  and  nitrogen, to
which, in certain structures, phosphorus, sulphur, iron, and
some earthy salts are added  in small quantity.   But we
cannot infer what the dietetic  qualities of any particular
kind are, merely from knowing which of  these  elements
predominates in its  compositon.   To  render  this more
intelligible,  I may add that  fibrin, which constitutes the
principal part of flesh or muscle, albumen, which forms the
white of eggs, and gelatine, so well known in the forms of
jelly and glue, possess very different properties, and yet are
all  composed of carbon, oxygen, hydrogen, and  nitrogen,
or,  in other  words, of pure charcoal  and three kinds of air
cr gas, the different  proportions of which give rise to'the
distinctive properties of each.  For  example—
                  Carbon. Hydrogen. Nitrogen. "Oxygen.
    Fibrin consists of   53.36    7.02     19.934   19.635
    Albumen, .    .   52.883    7.54     15.705   23.872
    Gelatine,  .    .   47.831    7.914    16.993   27.207
  It may seem strange that such small  differences should
produce so great a difference in the resulting compounds ;
but when we consider that the air which we  breathe is
composed of merely different  proportions  of the same ele-
ments  as nitric acid or  aquafortis,  which corrodes  and
destroys the living structure, our surprise will cease.  The
atmosphere consists of 79 parts of nitrogen to 21 of oxygen,
whereas nitric acid is composed of 70 parts of oxygen to 30
ef nitrogen,  and yet  what a difference in their properties !
  It appears, then, that a knowledge of the merely chemical
composition of any animal substance throws very little light
on its eligibility as an article of diet.   We cannot infer, for
instance, that, because fibrin contains more carbon and less
oxygen, it must, therefore, be more  stimulating or more
nutritious than gelatine.   Experience alone can teach us
the qualities of either, and determine their relative fitness
for individual constitutions.   The case is, however, diffe-
rent with what is called in chemical language the proximate
or compound animal principles, such as fibrin, albumen, and
gelatine, which enter, in different proportions, into the com-
position of every animal tissue.  Each  of these principles
                          19* 
wz
FIBRINOUS ALIMENTS)1.
 possesses distinct properties, which may be modified by th*
 presence of  the others, but which  can still be  recognised
 more or less  easily in every animal part, according to the
 proportion which it bears to the rest.   On this very circum-
 stance, indeed, the best practical classification of the diffe-
 rent varieties of animal food is founded, because the general
 properties of each as  an article of diet can be  inferred with
 tolerable  accuracy from the relation which its predominant
 principle  bears to those which are  subordinate.
   Acting in accordance with  this standard, most writers
 on dietetics  classify  all the  kinds  of  animal food into the
 fibrinous, gelatinous, and  albuminous, according  as fibrin,
 gelatine, or albumen  predominate in their composition, and
 for ordinary  purposes the  arrangement is  sufficiently ac-
 curate.  To  these, however, the class of fishes requires to
 be added.
   Fibrinous  aliments.—Fibrin is that whitish and tenacious
 mass which constitutes the solid part  of coagulated  blood,
 and which appears almost free from colouring matter in what
 is called  the huffy coat or white surface  of  blood  drawn
 during active inflammation.  It is most easily obtained by
 stirring recently drawn blood with a stick,  to which it
 adheres in proportion as it coagulates.   From this coagulum
 the colouring particles may be removed by washing with
cold water, the residue being fibrin nearly pure.
   Fibrin enters largely into the composition of the muscles,
and indeed, with the addition of some gelatine and albumen,
forms their principal ingredient.  Hence all kinds  of flesh-
meat are essentially fibrinous aliments, and they differ from
each other chiefly in the different proportion which the fibrin
bears to  the  other  ingredients in each.  Thus beef and
mutton  are   more purely  fibrinous than  veal and  lamb,
because in the former, and  in most animals of mature age,
the fibrin  exists  in  larger  proportion  to the gelatine  and
albumen than in  the latter and in young animals.
   Fibrin is considered the most nutritive of all the  alimen-
tary principles, or, in  other words, it contains the largest
quantity of nourishment in the smallest bulk.   Fibrinous
aliments, accordingly, remain longer in the digestive  tube
than any others  ; and, during their digestion, they excite
the circulation in a higher degree in  the vessels of the
mucdus coat, and cause a more abundant secretion of the
fluids required for  their solution.  They are also  mors 
FIBRINOUS ALIMENTS.
22^
completely altered in composition, and  leave  less residue
in the  bowels, than other kinds of  food ;  but from these
very circumstances they are also the most stimulating of
all aliments, and  those which  most excite the production
of animal heat, and afford  the best  support under severe
exertion and great exposure to cold  or inclement weather.
On this account, the kinds of meat which contain fibrin in
its most concentrated form constitute the most appropriate
food  in the arctic  regions, and the quantities in which they
are consumed and digested  are  such as in our temperate
climate would altogether overpower the system.  For the
same reason, fibrinous aliments are too exciting to be used
with the  same freedom in warm climates, or during hot
Weather, as in cold climates, or during winter.
   The kinds of meat in which fibrin  principally abound are,
beef, mutton, pork, wild boar, venison, hare,  duck, goose,
&c.   Generally speaking, those meats which are dark in
colour  contain more fibrin and osmazome than those which
are paler.   For example, beef contains much  more than
veal or pork, and  goose more than fowls or turkey.  Those
kinds,  also, the fibres of which cohere most firmly, contain
most fibrin.
   Such being the effects of the fibrinous principle, it follows
that  the properties of the various kinds of animal food, and
their fitness as articles of diet, will depend very much on
the proportion which the fibrin bears to their other elements,
and on the degree to which the system requires excitement
and support.   If the individual is subjected to severe exer-
tion, or is of a soft, sluggish, lymphatic temperament, which
stands in need of a healthy stimulus, beef,  mutton, and
game,  in which fibrin  abounds, will  be very  appropriate ;
whereas, if he is naturally of a full,  sanguine,  and irritable
habit of  body, and not subjected to much  exercise, those
kinds which  contain the smallest quantity of fibrin—such
as chicken, fowl, turkey, and other white-fleshed animals
—will  be much more suitable.   For the same reason, red
meat i3 more appropriate as an article of food in  winter,
and  white in summer.
   In determining the  diet of invalids and convalescents,
the  same principle of  selection may be very usefully ap-
plied.   From over-anxiety to impart strength, it is a com-
mon practice to give a weak and excitable invalid a dinner
of beefsteaks or  roast meat, because these are know to be 
*'24               GELATINOUS MEATS.
more nourishing to a person in robust  health  than fish or
chicken ;  and surprise  is often expressed that,  notwith-
standing this excellent diet, debility makes progress, and
flesh is  lost  rather than gained.   Whereas, if the  excita-
bility of such invalids, and the invariable tendency of strong
fibrinous food to  increase that excitability, were kept in
view, it would speedily be discovered that a gross error
has been committed, and that the milder white  meats would
give more real  support, simply from being better fitted to
the then state of the constitution.
   The mistaken practice here noticed often arises from two
very different things—digestibility and fitness  as an article
of food—being confounded  together.   The stomach may
haye no difficulty whatever in digesting a slice of roast
meat, and yet the latter be very ill suited  to the state of the
system  at the time ;  while, on the other hand, a meal of
fish  or of vegetables may be very  slowly digested,  and yet
be in every  way the best adapted to the then bodily condi-
tion.  So that, in selecting a proper diet, we must not be
guided only by the abstract properties of the articles chosen,
but constantly have in view their  relation to the individual
constitution and circumstances of the person who is to use
them.
   Gelatinous meats are so called  from containing a large
proportion of jelly or gelatine.  Gelatine is found in the
muscles, skin, ligaments, tendons,  membranes, and bones ;
but it abounds most in the flesh of young animals, as, in veal
or lamb, of which we have a  familiar example in the jelly
found in cold veal pies.  It is also procured in large quan-
tity from the skin, ligaments, and tendons,  especially of
young animals.   The very name  calfs-foot jelly indicates
this  origin ; and glue, which is an impure  gelatine, is well
known to be procured chiefly by boiling scraps  of dried skin
till the whole of their gelatine is extracted.
   Veal, lamb, fowl, and the young of most animals in which
the colourless predominate over the red particles of the blood,
constitute the principal varieties of gelatinous meats.   In
their effects  on the system they are slower of  digestion,
less exciting, and less heating  than fibrinous aliments.   In
weakened constitutions, consequently, they often  require
to be combined with stimulants, such as  spices, to rouse
the stomach to their digestion.  Without  this precaution,
they sometimes pass quickly through the intestines almost 
GELATINOUS MEATS.
22b
unchanged, and thus seem to have a laxative effect, when
it is their want of stimulus that is alone in fault.
  Gelatinous aliments, when properly digested, are very
nutritious, without  being stimulating.   They  fill up the
system rapidly, but  without  communicating to it the same
enduring vigour as fibrinous meats.  From the above pro-
perties, gelatinous food ought to be preferred where a ten-
dency to excitement exists and requires  to be moderated.
It is well adapted, for example, to persons of a dry, irrita-
ble  constitution, to  excitable children, and to those whose
muscular labour is not so great as  to require more stimu-
lating or nutritious  food.  For  the same reason, it  is well
adapted to persons recovering from illness, and to whom the
red or fibrinous meats would prove too stimulating.  Ac-
cordingly, chicken tea, chicken, calPs-foot jelly, lamb, veal,
and other gelatinous aliments are  in common  use among
invalids ; not because they are more digestible  than beef
tea, roast beef, or  mutton-chop,  (for, in reality, they are
digested more slowly,) but because they are  less stimula-
ting, and, therefore, safer, and less apt to excite a relapse.
Indeed,  from this very want of stimulus, they are apt to
disagree with weak stomachs, unless seasoned with a good
deal of spice or vinegar ; and hence the practice of sending
slices of  lemon to table along with them, and also that of
adding vinegar to their sauces.
   Gelatinous meats are peculiarly ill adapted to persons of
a sluggish, lymphatic constitution, or living in a low, damp
situation, because  in both  instances they afford an inade-
quate stimulus to the circulation.   They suit best for indi-
viduals of a very  excitable temperament, or living in a high
 and dry locality,  where support is wanted, and the animal
vigour requires  to be soothed  rather than excited.  And,
consequently, in determining their fitness in any individual
 case, we must be guided entirely by the effect we wish to
 produce.  As a  general rule, gelatinous  meats promote the
 action of the bowels more than fibrinous.
    Many experiments have been made, especially in France,
 to  ascertain whether gelatine, m  the form of soup made
 from bones, and  eaten along witn bread,  is sufficient to con-
 stitute the sole  or principal nourishment  of  man.  The
 question is one of great importance in an economical point
 of view, especially in public institutions in which  this kind
 of aliment has, from its cheapness and supposed salubrity, 
22S         EXPERIMENTS ON THE NUTRITIVE
been long in extensive  use.   The following  is an outline
of the results obtained by  Messrs. Edwards and Balzac,
whose experiments  may be regarded as perhaps the most
trustworthy, although they cannot be said to have entirely
settled the question:
  When dogs were fed upon bread and a soup or solution
of gelatine, they gradually became thinner and weaker, till
they at last perished "when reduced to about one-sixth of
their original weight.   But if soup made from meat  was
substituted for that of gelatine, even  when  the weakness
was extreme, recovery speedily followed, and in seven days
the  dogs regained the  whole of their lost weight.   This re-
sult is the more remarkable, because the only appreciable dif-
ference  between the  two kinds of soup consists in the
almost evanescent principles  which give flavour and smell
to the one, and the  absence of which leaves the other com-
paratively vapid and  tasteless.  On farther examination,
M.  Edwards found  that a very small addition of these ap-
parently insignificant  principles sufficed to render gelatine
soup  as nutritive as that  made entirely from meat.   This
singular fact was demonstrated, by first feeding  a young
dog on  meat and bread for twenty-three days, and noting
the regular increase of its weight during that time.   The
same dog was then fed  for  thirty days on'gelatine  and
bread.  During  this time  it lost, not  only all its recently
acquired, but also one-fifth of its  original  weight.   Two
table-spoonfuls of soup made from horse-flesh, containing,
of course, the sapid and odorous principles, were then added
to fourteen of the gelatine soup twice a day, and formed
with the bread into a  soft paste.   This slight addition of
four table-spoonfuls, in twenty-four hours, of the meat soup,
differing from the other only in its sapid and odorous prin-
ciples, sufficed completely to restore the animal.   From the
very first meal there was an increase of weight, rapid growth
commenced, and in twenty-five days the dog had gained
considerably more than its original weight, and was in the
enjoyment of vigorous health and strength.   These remar-
kable results show how great a difference of dietetic proper-
ties may arise from even  the slighest change of chemical
composition, and how  necessary it is to have recourse on
all  occasions to actual observation before deducing general
conclusions from apparent analogies of nature.
  From the whole of  his experiments, M. Edwards infers, 
              PROPERTIES OF GELATINE SOJP.         227

"1.  That gelatine alone is insufficient  for alimentation.
2. That, although insufficient,  it is not unwholesome.   S.
That gelatine contributes to alimentation, and is sufficient
to sustain it  when it is  mixed with  a due proportion of
other products, which would themselves prove insufficient
if given alone.   4.  That gelatine  extracted  from bones
being identical with that extracted from other parts ;  that
bones being richer in gelatine than other tissues, and  able
to afford two-thirds of their weight of it, there is an incon-
testible advantage in making them serve for nutrition in the
form of soup, jellies, paste,  &c. ; always, however, taking
care to provide a proper admixture of the other principles
in which the gelatine soup is defective.   5. That, to render
gelatine soup equal in nutritive and digestible qualities to
that prepared from meat alone, it is sufficient  to mix  one-
fourth  of meat soup with three-fourths of gelatine soup, and
that, in fact, no difference is perceptible between soup  thus
prepared and that made solely from  meat.  6. That, in pre-
paring soup in this way, the great advantage remains, that,
while the soup itself is  equally nourishing as meat soup,
three-fourths of the meat which would be required for the
latter,  by  the common process of making soup, are saved
and made useful in  another way, as  by roasting, &c.  7.
That jellies ought always to be associated with some other
principles to render them both  nutritive and digestible."*
   From these results it  may be inferred  that the  practice
followed in most of our prisons and charitable institutions,
of making soup from  ox  heads, bones, and the  coarser
pieces of  meat, is judicious as regards both wholesomeness
and  economy; because, while  the   bones, especially if
broken into fragments,, yield a large quantity of nutritious
gelatine, the meat attached to them  is quite sufficient to
supply the required proportion  of the  more volatile princi-
ples.   The additional admixture of barley and other vege-
tables  also increases its  digestibility and nutritive power.
   Albuminous aliments, or those in  which  albumen  pre-
dominates, are at once easily digestible and very nourish-
ing.   Albumen itself is found in  the blood and  various
other parts ; but it exists nearly pure in the white of eggs.
In its  liquid  state it is colourless and transparent,  without
smell  and with little taste.   It coagulates or becomes firm
by boiling or heat, and is more digestible the nearer it ap-
     ♦ Londe's Elemens dHygiene, 2d edition, voL ii., p. 73. 
223
ALBUMINOUS ALIMENTS.
proaches to the  liquid state.  Of this we have a familiar
proof in the superior digestibility of soft over hard-boiled
eggs-
  Albuminous aliments are highly nutritious without being
stimulating, and hence are very appropriate  in  excitable
nervous constitutions, and during convalescence from dis-
eases characterized by excitement and irritability.   For the
same reason, they  are  inappropriate for persons of a lym-
phatic temperament, or undergoing great exposure or severe
labour.   In their coagulated state they are more difficult
of-digestion, but support the strength better: and  hencie
the use of  hard-boiled eggs, by sportsmen and  travellers.
I need  scarcely add that, for persons  of  a bilious  or san-
guine temperament, engaged in sedentary occupations, and
with no outlet for  their activity, albuminous  and gelatinous
are preferable to the more stimulating fibrinous aliments.
  Eggs of all kinds constitute  the largest  class of albu-
minous aliments,  and, when perfectly  fresh, and  not over-
done, they generally agree well  even with weak stomachs.
When  long kept, however, they  are  often productive of
heat and irritation.
   Oysters are another of the albuminous articles of diet
in very common use.   In their fresh state, and eaten along
with the salt water contained in their shells, they prove
very digestible ; but when boiled or stewed,  they become
tough  and resisting, and lie long on the stomach.
  Brains  owe their digestibility and nutriment  chiefly to
the  albumen which they contain ; and with  many people
are a favourite food.
  Those  of the albuminous aliments, such as  eggs and
brains,  which possess  no stimulant properties, are  consi-
dered by Londe to be very suitable where the stomach is
irritable, and during convalescence, where  much nourish-
ment is required.   He thinks them well  adapted also for
old  men, females, and literary people.   Those  of them,
again, which, like the oyster, are of a stimulating nature,
are suitable enough in cases of impaired digestion, but de-
cidedly hurtful  where the mucous membranes are in an
irritable state.
   In addition to fibrin, gelatine, and albumen, animal sub-
stances contain  another principle of a very peculiar nature,
called osmazome.   It is this principle which gives to roast
and broiled meats their distinguishing taste and dark colour. 
FISHES CONSIDERED AS ALIMENTS—VEGETABLE FOOD. 229
Jl is not  found at all in the flesh of very young animals,
but forms as they advanced in age.  It is far  more abun-
dant sn red than in white  meat, and, indeed, forms one of
the chief distinctions between them : and it is its absence
which gives the want  of  taste and colour to  chicken and
veal tea,  as  compared with beef tea.  Its influence on
digestibility and nutrition has been  already shown in the
experiments of Dr. Edwards on  the nutritive qualities of
gelatine in soup.
  There still remains  to  be noticed another class of  ani-
mal aliments, in which the fibrinous, gelatinous, and albu-
minous principles appear in nearly equal proportions, viz.,
Fishes.
  Fishes, as  remarked by Londe,  differ  also from  the
mammalia and birds in containing no osmazome, and, con-
sequently, in wanting  that savoury and  exciting principle
which gives the peculiar zest to  roast meat, and are, con-
sequently, well adapted for those who require  nourishment
without stimulus.   Those fishes which are firm  affil co-
herent in  their texture, as compared with  others, are the
most difficult of digestion, and contain the largest propor-
tion of fibrin.
  Fish, generally speaking, is digested slowly, but without
difficulty.  From its nourishing without stimulating, it is
not well  adapted for persons of a lymphatic  and  inactive
constitution, but it is very suitable for those of an energetic
or excitable temperament, such  as the bilious or nervous-
bilious, especially when no great bodily exertion is incurred.
For the same reason, it is often a safe aliment during con-
valescence from illness, where animal food cannot be ven-
tured upon with safety.
   The second great division of  alimentary substances in-
cludes tho.se belonging to the vegetable kingdom; but on
the properties of these I must be very brief.   For practical
purposes  they may be subdivided-into Farinaceous  and
Leguminous, the former  including wheat, rice, potato, ar-
row-root, and the different kinds of grain ; and the latter
all green or fresh vegetables and fruits.
   Farinaceous food is both easily digestible and highly nu-
tritious.  In the experiments of  Dr. Beaumont, sago,  rice,
and arrow-root in  quantities  of  a pint,  were  found, when
well boiled, to be entirely digested in little more than an
hour.   In this respect it  differs  from  ordinary vegetables.
                            20 
230          VEGETABLE FOOD AND FRUITS.

which, as we have seen, often pass into the intestine com-
paratively unchanged.   Londe remarks that farinaceous
aliments pass out of the stomach most rapidly and afford
least nourishment when most fermented.   They are, how-
ever,  the most nutritious of all vegetable substances,  and
neither excite the circulation nor increase the animal heat.
This effect becomes very apparent when we pass  at once
from an animal to a farinaceous diet.  The circulation  and
all the other functions become lowered.
  Fresh vegetables and fruits contain a very large propor-
tion  of water in their  composition, and  hence they are
much less nourishing than animal or farinaceous food.   But
for this very  reason,  they are very unexciting, and may be
used  with  great  advantage in inflammatory states of the
system and during hot  weather.   Even in temperate cli-
mates a due admixture of fresh vegetable food  seems to
be highly conducive to health, especially  during  summer.
In the arctic regions, however, it affords too little stimulus
to be used in any quantity, and hence the universal prefer-
ence  among the  natives of a purely animal diet.  In the
winter of our own climate, also, the desire for vegetable
food is less active than in  summer, and hence the greater
use of meat during that season.
   In the United States of America an active and numerous
sect has of late years sprung up under the auspices of  Syl-
vester Graham against the use of animal food in any form
or quantity, and in favour of the exclusive  use of vegetable
aliment and  water as the natural food of  man.   Already,
as has been done with  so much  effect by the friends of the
Temperance cause,  societies have been  formed,  tracts
printed, and missionaries sent  forth in aid of this principle.
Numerous examples have also been published by Dr. Alcott
and others of restored and improved health, arising from the
exclusive use of vegetable food  where every other means
had failed ; but I cannot help thinking that both Dr. Alcott
and  Sylvester  Graham have  unconsciously argued  their
cause with too much  of a one-sided and exclusive zeal, and
advocated  conclusions which  a  larger and less  equivocal
experience would disown.   They have, however, brought
forward a mass of valuable information bearing upon a  very
important question connected with the welfare of man,  and,
whether they are right or wrong in their leading principle,
they deserve the gratitude of the public for their exertions. 
         ADAPTATION OF DIET TO CONSTITUTION.      231

If health permits, I  trust to be enabled in a future edition
to do greater justice to their views, by entering into more
detail on this part of the subject;  but I must for  the  pre-
sent content  myself with remarking, that vegetable food and
fruit might, with propriety, be used  by the middle and richer
classes  in this  country to a greater  extent than it is, and
that it is really wanted as one of the means of counteracting
that tendency to  constipation  which  is now so prevalent
among them.*  A very general  prejudice exists against even
the moderate use of vegetables, on  the supposition that they
are  indigestible and  unwholesome,  where, in  truth, it  is
excess in the quantity of food eaten that is alone to blame.
If the diet be moderate in quantity and duly adapted to the
habits of the individual, a fair proportion  of vegetables will
be digested without difficulty, and prove more advantageous
to the general  health than a diet composed exclusively of
either animal or  vegetable food.  In the next chapter  I
shall briefly touch upon the adaptation of diet to constitution,
age, season,  and  mode of life ; but  I may here mention,
that, in preparing  the preceding observations for the press,
I have derived much assistance from the excellent wori of
M. Londe, already repeatedly referred to, and which I can-
not but recommend  to the professional reader as the best
we possess on the general subject of Hygiene.

                     CHAPTER  V.
ADAPTATION  OF DIET TO CONSTITUTION, AGE, SEASON, AND
                      MODE OF LIFE.
Food to be adapted  to constitution and circumstances—Diet  must
  vary with time of life—Diet in infancy—The mother's  milk the
  best;  substitutes  for it—Over-feeding  a prevalent error—Diet
  after weaning—Too early use  of animal food hurtful—Diet of
  children in the higher classes too exciting ; and produces scro-
  fula—Mild  food best for  children—Incessant eating very inju-
  rious—Proper diet from childhood to  puberty—It ought to be full
  and nourishing, but not stimulating  ; often insufficient in board-
  ing-schools—Diet best adapted for mature age—Regimen powerful
  in modifying the constitution, mental as well as physical—Far-
  ther investigation required.
   After the exposition contained  in the preceding chapter,
 it will,  I trust, be  considered unnecessary to adduce any far-
 ther evidence to show that, in practice, a distinct modifica-
 tion of diet  ought to be  adopted for  every marked  variety
 of constitution, as, unless a proper  relation subsists between
 the qualities of the food and the nature of the system which 
232     ADAPTATION OF FOOD TO CONSTITUTION.

it is intended to nourish, due advantage cannot be obtained
from its  use.  For example, the highly concentrated and
stimulating food which  is found necessary for  the  proper
sustenance of the trained pugilist or sportsman, whose mus-
cular frame is in high developement and constant exercise,
would  prove far too exciting to the slender and irritable
constitution of a person whose characteristic feature is the
predominant activity of the brain and nervous system.   In
like manner, the generous and  stimulating diet which suf-
fices to merely rouse a phlegmatic organization  to ordinary
energy, would prove by  far too nutritive for a person of a
florid and sanguine  temperament,  whose predisposition is
already toward  inordinate activity.
  Viewed in this  light, the necessity of adapting the diet
and regimen to the individual constitution and mode of life,
becomes so obvious to reason  as to excite surprise that it
should ever have been neglected.   But, strange to say, al-
though the ancient writers attached much importance to the
subject, the relation between diet and constitution, as a prac-
tical consideration, has, of late,  been so entirely overlooked,
and sound physiological principle has been so little consult-
ed in the proper adaptation of the one to the other, that we
are at  this moment in possession of very little information
of any value regarding it, and a long time must elapse be-
fore more can be supplied.   My own observations are not
yet sufficiently matured to warrant my submitting them to
the public ;  and, therefore, the following imperfect remarks
are subjoined, rather in the hope of exciting inquiry than of
satisfying the curiosity of the reader :
  Where the constitution is of  a mixed nature, or a com-
pound of two or more of the temperaments already described,
a diet composed of animal and  vegetable aliment in nearly
equal proportions is, under ordinary circumstances, the best.
But  where any one temperament predominates, the diet
ought to be  modified accordingly.  Where, for example,
the  sanguine constitution prevails, characterized by a florid
complexion, great  activity, strong action of  the heart and
bloodvessels, and a consequent  liability to diseases of  ex-
citement  and inflammation, the  food ought to be habitually
of a kind calculated rather to sooth than to stimulate.
Red meat, spices,  wines, and fermented liquors ought  be
used sparingly ; and the principal support  to be derived
from refreshing soups, fish, fowls, mucilaginous vegetables, 
         DIET TO BE ADAPTED TO TIME OF LIFE.       233

acidulous fruits, and-diltiting  drinks.  In the case of lym-
phatic persons, on  the other hand, where the circulation is
weak and slow, and all the functions are feeble, the system
is benefited by  the stimulus of a larger proportion of ani-
mal food, especially red meat and game ;  while vegetables,
soups, and fluids of all  kinds prove relaxing  and hurtful.
Aromatics and spices, however, are useful, as is also wine
in moderation, and conjoined with adequate exercise.
  If, again, the individual presents a highly nervous tem-
perament, characterized by delicacy, unusual sensibility to
impressions, and  great  excitability, without  proportionate
strength, such as is often seen in females and in men of ge-
nius, care ought to be taken not to make use of a heating or
stimulating regimen.   White meat, such as fish and fowl,
are more suitable than the kinds in ordinary use.   Spices
are also hurtful, but farinaceous and mucilaginous aliments,
and ripe  fruits, are generally admissible—always supposing
that moderation in quantity is  attended  to, and  that the
mode of life is, in other respects, regular and rational.
  Where the dark energetic  bilious temperament predomi-
nates, and much bodily  activity in the open air is  enjoyed,
more latitude in  the  choice  of food is admissible than in
any other constitution.   If, however, much and continued
exertion  be required,  a full supply of animal food  becomes
indispensable for the due support of the system, and the
strength cannot  be adequately  supported on vegetables
alone.   In such circumstances a  moderate allowance of
wine or other stimulus is borne with less  detriment, if not
with more advantage, than where the temperament is essen-
tially nervous.
   On this subject, however,  there is still so much need for
inquiry, that I shall for the present only refer the reader to
the general principles explained in  the preceding chapter,
and urge upon him the necessity of rendering our knowledge
more complete, by diligent and discriminating obversations.
  There is no  kind of alimentary substance of which it can
De said  absolutely, that it is  always proper for  the suste-
nance of man.  To be serviceable, the food  must, as we
have seen, be adapted, not only to the constitution, but to
the age, state of health, and mode of life of the individual,
and to the climate and season of the year.   The same diet
which, administered to an adult, is healthful and nutritious,
may prove irritating and  injurious  to a child; and, in like
                           20* 
234      DIET TO BE ADAPTED TO TIME OF LIFE.
 manner, the stimulating animal diet which in winter is highly
 grateful to the system of a hard-working unexcitable labour-
 er, may prove utterly destructive of health when indulged
 in during summer by an inactive and excitable female.  It
 becomes, therefore, an  object of deep interest to determine
 the principal causes and states of the system which render
 modifications of diet necessary.
   Amonor these modifying causes, the varying state of the
 body at different periods of life ought certainly  to be con-
 sidered as one  of the most  influential.   The  differences
 observed in  the constitution of the same person at different
 ages are at least as great as those subsisting between diffe-
 rent individuals at the same age.  In infancy the lymphatic
 and nutritive functions greatly predominate  over the  mus-
 cular ; and  if the highly animalized food which suits the
 latter were then freely administered, it would infallibly in-
 duce disease, and fail  to afford the requisite nourishment.
 In manhood, again, when muscular activity and nutrition are
 at their height, the lymphatic system in abeyance, and the
 person subjected to laborious exertion, the mild  food of in-
 fancy would be equally  misplaced.  In advanced age another
 change of constitution occurs.  The soft tissues of  early
 life have disappeared, and the whole frame is dry and  wasted
 —a  condition which, in  its turn, requires food  of a diffe-
 rent kind from that fitted for either of the preceding stagee.
   With regard to the diet during the first two years of life,
it would be  superfluous to repeat here the exposition given
in the preceding editions  of this  work.  In my Treatise
on the Physiological and Moral Management of Infancy,
since published, the reader will find the subject  discussed
in all  its requisite details.   I may, however, remark, that
even the state of the digestive organs at different  ages is
sufficient  to indicate a  corresponding modification of diet
to be proper for each.  In early infancy, for example, when
no teeth exist, and the muscles which  move the jaws are
 still small and comparatively powerless, and  mastication is
 consequently impossible, milk, from the mother's breast, is
 manifestly the only food intended by nature for its use ;  and,
 so long as it can be obtained of healthy  quality and in suffi-
 cient quantity, no other ought  to be substituted in its place.
   The appearance of the first incisor teeth, however, is an
 indication that the digestive organs have now become suffi-
 ciently developed to admit of small portions of barley water 
DIET IN INFANCY.
235
panada, thin arrow-root, or milk and  water, being  given
two  or  three  times  daily in addition  to the nourishment
drawn from the mother's  breast, if the latter be at all de-
ficient.   But  great care must be taken neither to exceed
in quantity nor to give the food too rapidly ;  for otherwise
the stomach will become too full, and be weakened by the
efforts it is obliged to make.  I have  already pointed out
the importance of attending to this rule ; and, in accordance
with it, Nature, by arranging that the milk shall flow only
by slow degrees, has taken care that, in suckling, the child
shall receive  its food very gradually.  The very appear-
ance of the teeth indicates a preparation of  the  digestive
functions for more substantial aliment; and by beginning
cautiously the use of small quantities of such simple articles
as those above-named, and gradually increasing them ac-
cording to the wants of the system, an excellent preparation
will be°made for the process of weaning, which would other-
wise, by its suddenness, be  attended with serious risk  to
both parent and child.
   After the  child has been  weaned, panada, gruel, thin
arrow-root, tapioca, sago, rusk, or crust of bread may be
allowed along with the fresh  milk  and water and  sugar,
which ought still to constitute the principal part of the food ;
and one  or other ought to  be preferred according to its
effects.  When these are given in moderate quantity, and
not too frequently, they generally agree well;  but in some
delicate children they cause acidity, flatulence,  and griping.
In this case  a proportion of  weak chicken broth, or beef
 tea freed from fat and thickened with rusk, soft-boiled rice,
 or arrow-root may be added.
   The same kind of food ought to be continued till  after
 the appearance of the canine or dog-teeth.  When these
 have fairly protruded, a portion of soft-boiled  egg may be
 given as an introduction to the use of a more completely
 animal diet.   In general, solid animal food ought not to be
 allowed in  any quantity till all the teeth have appeared and
 the digestive powers be fully adequate to its assimilation.
    In this respect there are two errors which ought  equally
 to be avoided.  If animal food be given too early or in too
 great quantity, the system becomes excited, and diseases
 of irritation are apt to be produced, which impede nutrition,
 and lead ultimately to the production of scrofula and other
 organic  changes in the glands and bowels,  and not unfre- 
236        EVILS FROM ILL-REGULATED DIET.
quently also in the brain  and lungs.   In these instances
the child generally eats heartily, but, nevertheless, continues
thin, and is subject to frequent flushing and irregularity of
the bowels, headache, and restlessness.  His mind partakes
of the general  irritability  of the  system,  and peevish im-
patience takes the place of the placid good-humour natural
to healthy childhood.  In this state the ordinary diseases
of infancy—measles, scarlet fever, and hooping-cough—are
often  attended with an unusual and dangerous degree of
constitutional  disturbance ;  and, when inflammation takes
place, the necessary depletion is borne with difficulty, and
the system does not easily rally.
  The consequences now enumerated, and the error from
which they spring, are most frequently met with in the mid-
dle and higher classes of society.  Aware that animal sub-
stances contain the largest proportion of nutriment in a given
bulk, but ignorant of the relation subsisting between particu-
lar kinds of food and particular states of the  system, and
which, in practice, can never be safely overlooked, the fond
parent naturally imagines  that the more nutritious the food
and the larger the quantity administered,  the stronger and
healthier will the child become. No suspicion is entertained
that strong diet may overpower weak  organs, and thus in-
duce the very evils which it is sought to avoid ;  whereas, by
adapting the quality and quantity of the food to the condi-
tion of the system, the assimilating powers may be gradually
invigorated, and healthy nutrition be completely ensured.
  Among the wealthier classes  imperfect nutrition  most
generally arises from excess in  quantity, or a too stimu-
lating quality,  of food;  but among  the lower classes from
deficiency in quantity or  quality, added  to scantiness of
clothing, want of cleanliness, and imperfect  ventilation.
And hence Sir James Clark, in treating of the prevention
of scrofula and consumption in early life, lays  great stress
on the proper  regulation of diet, and  shows that, even in
families free from all hereditary taint, a morbid condition
of the system extremely favourable to the production of both
diseases, is speedily brought about by continued mismanage-
ment of diet; and both the public and the profession are
deeply indebted to him for drawing attention to the extensive
influence of dyspeptic ailments in  paving the way for the
future inroads of a deadlier disease.   It is true that it has
long  been the fashion to ascribe  all bodily and mental dis. 
EVILS FROM ILL-REGULATED DIET.        237
orders to bile, indigestion, or the state of the bowels ; but
the rationale of the result has seldom been perceived, or
turned to any good account in improving  preventive or
remedial treatment.   Sir James Clark's treatise, however,
presents a remarkable exception, and may be referred to as
a most instructive specimen of cautious and discriminating
medical inquiry.
  But although the premature use of animal food is thus
injurious, a  certain proportion of it  becomes essential to
health after the organization has  become  sufficiently de-
veloped ; because  the instruments of mastication are now
fully adequate to their office, and the stomach is no longer
oppressed by the effort of digesting it.   To make it safe,
however, even at that age, ample exercise and exposure to
the open air are indispensable.  By undue  confinement to
the house or to school, and deficient exposure to the air, a
degree of general delicacy may be kept up which is incom-
patible with the daily use of  a stimulant animal diet.  The
waste occasioned by bodily  action being then  too limited
to require the copious  supply of any very nutritious sub-
stances ; if these be freely allowed, they serve only to op-
press the digestive functions and impair the health.
   The prevalent and pernicious custom of tasking the minds
and confining the bodies of children for many hours in suc-
cession at home  and in  schools, at a time of life when the
growth of the body and the  welfare of the  system require
frequent and playful exercise in the open air, and perfect
freedom from care and  excitement of mind, is the fruitful
source of much future bad health,  and is eminently calcu-
lated to defeat the object aimed at by parents, namely, the
mental excellence of the  child.   The premature exertion
of intellect to which it is stimulated by the constant excite-
ment of emulation and vanity, far from strengthening, tends
to impair the health and tone of the brain, and of all the
organs depending on  it; and hence we rarely perceive the
genius of the school manifesting in future years any of the
superiority which attracted  attention in early life ; but we
find him, on the contrary, either sunk below mediocrity, or
dragging out a painful existence, the victim of indigestion
and melancholy.  On the other hand, some of the most dis-
tinguished men  who  ever lived were in childhood  remar-
kable only for health, idleness, and apparent stupidity. The
illustrious Newton was, by  his own  account, an idle and 
238
DIET IN YOUTH.
inattentive boy, and " very low in the school," till he reach-
ed twelve years of age ;  and the young Napoleon himself
is described as " having  good health, and  being  in other
respects  like other boys."   Adam Clarke was considered
" a grievous dunce" when a boy, and was seldom praised
by his father, except for his ability in  rolling large stones,
which his robust frame and good health enabled him to do.
Shakspeare, Gibbon, Byron, Scott, and Davy were  in like
manner undistinguished  for precocious genius, and were
fortunately allowed to indulge freely in those wholesome
bodily exercises, and  that freedom of mind, which  contri-
buted so much to their future excellence.   The mother of
Sheridan, too, long regarded him as " the dullest and most
hopeless of her sons."
  Among the many who give great promise in early life,
and whose talents are then forced by  ill-judged cultivation
into precocious maturity, how few live to  manhood  to reap
the reward of their exertions, and  how few of those who
survive preserve their superiority unimpaired !  Tasso  was
early distinguished, and wrote his immortal epic at twenty-
two years of age, but his life was miserable and his reason
disordered,  and he  died at  fifty-one.  Pascal is another
example of the same result, and Kirke White and many
Others might be named were it necessary.*
   Expedience, indeed, amply demonstrates that precocious
and excessive activity of  intellect and vivacity of feeling are
most powerful impediments to healthy and vigorous diges-
tion, and, consequently, to  a sufficient nutrition.  In early
life, therefore, when not only health but future usefulness
depend mainly on  the completeness and vigour with which
the system shall  proceed  toward  its  full  developement,
the preservation of the  digestive organs by suitable diet,
exercise,  and regimen,  ought to be  a primary object of
attention  with every  sensible  parent.  Even as regards
superiority of mind, the healthy developement of the  body
is of essential importance, as the only sure foundation on
which mental excellence can be built ; because, so  long as
mind  and body are intimately connected with  each other,
the former must continue to be affected by every change in
  * On this and kindred subjects, the reader will find much valu-
able information in  Mr. Brigham's Remarks on the Influence of
Mental Cultivation and Mental Excitement upon Health ; reprinted,
with excellent practical Notes, by the lateDr. Robert Macnish 2d
edition, Glasgow, 1836. 
DIET TO BE ADAPTED TO MODE OF LIFE.      239
the condition of the organization on which it depends.   We
enjoy acuteness of vision by preserving  the  eye in  high
health, and exercising it regularly and moderately ;  and, in
like manner, we can obtain and preserve intellectual power
only by preserving the health of the brain, and exercising it
in conformity  with its natural constitution.
   Instead, then, of  feeding the closely confined and  exci-
table children of the middle  and higher classes from  early
infancy on quantities of stimulating animal  food, and  even
giving them wine and fermented liquors, we shall act-more
in accordance with the laws of Nature by restricting them,
during the three or four earliest years of childhood, chiefly
to a mild farinaceous diet, with a  small allowance of meat
on alternate days ;  and by seeking to increase their diges-
tive power and bodily vigour by constant exercise in the open
air, before giving them a more solid diet.  By these means
the developement of the organization, the keenness of  appe-
tite, the tone of digestion, and the desire  of, and fitness of
the system for, animal food will increase in  regular propor-
tion, and a free supply of that species of aliment will even
become necessary to carry on the growth.  In short, it must
ever be remembered, that strength is to be obtained, not
from the kind of food which contains most  nourishment in
itself, but from that which is best  adapted to the condition
of the  digestive organs at the time when  it  is taken.
1   Children who are prone to bodily exertion, and live almost
entirely in the open air, as many of those of the lower orders
do, and who display no  unusual sensibility or  activity of
mind, or, in other words, no  unusual  irritability  of the ner-
vous system, not only bear but require a larger proportion
of animal food than  their more delicate and sensitive  com-
panions.   Not only is their digestion more vigorous, but the
waste going on in the system is much greater and the nu-
tritive functions are more  active ; the need, consequently,
for nourishing food,  and the desire to procure it, are propor-
tionally increased.   Hence it happens that, in the wealthier
classes of society, young children suffer most  from  over-
feeding ; while in the poorer classes they suffer chiefly from
the opposite  cause.   In both, defective nutrition is  the
result;  but the modes in which it is brought about are very
different.
   One of the most pernicious habits  in which children can
be indulged is that of almost incessant eating.   Many mo- 
240           INCESSANT EATING HURTFUL.
thers encourage it from the facility with which, for a time,
the offer of " something nice " procures peace.   Even from
infancy the child ought to be gradually accustomed to eat
only when hungry, and when food is really required.  After
two years of age, an interval of four hours between meals
will rarely be more than enough; and to give biscuit, fruit, or
bread in the meantime, is just subtracting from the diges-
tive power of the stomach.   Like almost every organ of the
body, the stomach requires a period of repose after the labour
of digestion; and, accordingly, in the healthy state, the sen-
sation of appetite never  returns till it  has been for  some
time empty.  To give food sooner, therefore, is analogous
to making  a weary traveller walk on without the refresh-
ment of a halt.
  It is a great  mistake to suppose that children would not
be quiet or contented without such indulgence.   On the con-
trary, they  wodld be healthier and happier were  the opposite
system steadily pursued.  The greatest obstacle  to be en-
countered is the ignorance of the nurse or mother, and her
want of resources for the entertainment and exercise of the
child's  bodily and mental faculties.   If these  be  duly at-
tended to, the child will  not think of eating till the return
of appetite enforces the demand ;  whereas, if it be left idle
and neglected,  everything will  be carried to its mouth, as
its only remaining resource against absolute inanity.  So
true is this, that I should regard that nurse as unfit for her   •
employment, who should complain that her charge, other-
wise in good health, is incessantly craving for something to
eat.   In this respect children are like adults.   Give them
something  to do and to think about,  and  they will  seek
meat only when hungry.   But leave them idle  and listless,
and eating will become their chief subject of contemplation.
  In a matter so important  as the rearing of children, one
would imagine  that every mother and nurse would be anx-
ious for instruction on  the nature, functions, and  wants of
the being committed to their fostering care.  And yet it is
notorious how rarely either one or other of them possesses
any but the crudest notions  of the animal economy, or can
give reasons for the practices they recommend, or modify
them in any degree to suit modifications of circumstances
and constitution.   In  reality the wonder comes to be, not
that so many children dio, but that so many survive their
early mismanagement. 
    THE YOUNG REQUIRE NOURISHING BUT PLAIN DIET. 241

   From the age of six or seven years up to that of puberty,
when the animal activity is at its height, growth in full pro-
gress, and the nutritive functions in their greatest vigour, a
larger proportion of animal food and a more generous diet
become necessary  to the enjoyment of health and vigour;
but they must still be  accompanied by ample exercise and
free exposure, otherwise  they will tend only to clog and
impede  the functions of life.  At  that age the  teeth and
other organs concerned in digestion have become developed
and fit for the assimilation of a richer aliment, and the rapid
growth which takes place renders an abundant provision of
the latter  in a manner indispensable.  It is then that  the
healthy  youthful appetite demands quantity as well  as
quality, and that digestion goes on  with an ease and vigour
which the dyspeptic parent  contemplates with a covetous
and regretful eye.
   At that age, indeed, the nutritive functions are so predo-
minantly active for the purpose of  carrying on growth, and
supplying  the rapid waste caused by youthful activity, that
if the natural craving for exercise  in the open air be freely
indulged, and due  attention be given  to the developement
of the bodily frame, the young may be very safely  left to
choose for themselves both the quality and quantity of theit
food.  In  such circumstances the  natural taste inclines so
essentially to the preference of plain substantial nourish-
ment, that there is very little risk of excess being commit-
ted.   But where the parents are intent only on the intel-
lectual advancement of their children, and accustomed to
subject them daily to many successive hours of confinement
and study, with only an hour or so of relaxation in the open
air, as is too commonly the case both with those educated at
home and in boarding-schools, an artificial state of being is
induced, which makes the rule no longer applicable, and ren-
ders necessary a more careful attention to dietetic regimen.
   Among the higher classes of society the unrestricted use
of the most exciting kinds and preparations of animal food
and the  daily use of wine, are the means generally resorted
to for the removal of  the delicacy thus engendered ;  but
when we consider the real state of  the case, no remedy can
seem more preposterous.  The evils to be corrected  are
imperfect  nutrition and the want  of strength.  The  im-
perfect nutrition, however, is caused, not by deficient food,
but  by impaired powers of digestion and assimilation, and
                          21 
242
ERRORS OF DIET IN YOUTH.
 these suffer only because the lungs are denied the free air,
 the muscles their necessary exertion, the brain its cheerful
 recreation, and the circulation the healthy stimulus which
 these united conditions infallibly produce.  Instead, there-
 fore, of oppressing a weakened stomach by administering
 stronger food than it has the power of digesting, the natural
 way of proceeding would  be to prescribe at first a milder
 and less stimulating diet—to improve the tone of digestion
 by fulfilling the conditions  above referred to—and then, in
 proportion as the stomach was  strengthened, to adopt  a
 more nourishing diet, suited to the increased efficiency of
 all the animal functions.
  By running counter  to this method, and using highly sti-
 mulating food improperly, many young people of the weal-
 thier classes incur as much suffering from imperfect nutri-
 tion, and the diseases  to which it predisposes, as if they
 were really the victims of an impoverished diet.   Sir James
 Clark, after making some  very judicious remarks on the
 influence of bad  digestion in inducing the consumptive con-
 stitution of body, expresses himself strongly on the evils to
 which I have just .alluded.  " Food in  excess," he says,
 " or of a kitid too exciting for the digestive organs, may also
 induce tubercular  cachexia—a circumstance which is not
 sufficiently attended to—I  may say, not generally under-
 stood, even by medical  men; nevertheless, I hold it to be
 a frequent cause of scrofula, and believe that it  produces
 the same effect on the system  as a deficient  supply."—
 " The imperfect digestion and assimilation in the one case,
and the inadequate nourishment in the other, being equally
injurious ; the forms and general characters which the dis-
ease assumes may differ, but the ultimate result will be the
same in both cases.   The  adaptation of the food, both in
quality and  quantity, to the age of  the individual, as well
as to the powers of the digestive  organs, is too little con-
sidered ; and the evil consequences of this neglect are often
evident in the children of  the wealthy classes of society,
who are allowed an unrestricted use of  the most exciting
kinds of animal food."*
  The opposite error, of not providing a  sufficiently nour-
ishing diet for the young, is, often from  kind but  mistaken
views, much more prevalent than it ought to be, particular-
ly in female boarding-schools, where, as already mentioned,
    * Clark on Pulmonary Consumption and Scrofula, p. 330. 
         ADAPTATION OF DIET TO CONSTITUTION.      243

the system of diet is frequently insufficient for due suste-
nance and  growth ; and where, consequently, the natural
expression  of impaired  health,  if not actual disease, is a
marked feature in the aspect of most of the  pupils.   So
defective, indeed,  is the common school management  in
this and other respects,  that we have the best authority for
considering it as a rare  exception for a girl to return home
in full health after spending two or three years  at an ordi-
nary English boarding-school.*
   It is true that much of this result is owing to excessive
confinement, neglect of cheerful exercise, ill-ventilated sleep-
ing apartments, and other depressing influences ;  but  to
these that of an insufficient diet may often be added ; and
when it does exist, it acts with  double force from  the im-
paired digestion, which seldom fails  to ensue where the
laws of health are so widely outraged.
   I have seen some striking instances of incurable scrofu-
lous disease, induced by the depressing influence of misfor-
tune added to the want of a sufficient supply of nutritious
food.  After the  mercantile disasters  of  1825-6,  many
cases of this kind occurred, especially in families  whose
sensitive feelings induced them  to shrink from public obser-
vation, and to suffer the severest privations rather than allow
their situation to become known.  In these cases the tone
of the general health first became reduced, and then local
disease was  easily excited by any trivial cause.  In  one,
the structu-e of the bones and joints became disorganized,
and amputation of the  limb preserved  life, but could not
prevent other parts of the osseous system from being attack-
ed.  In another, caries  of the bones of the foot  ensued, but   " ,
the  constitution  itself  was  so  thoroughly tainted  that  no
operation could be performed with even momentary success,
and, after much  suffering,  the patient  died.   The same
causes undermined  the health of another member of the
same family, and led to his death, from consumption, at  an
early age.
   In regard to the diet best adapted to different constitu-
tions in mature age, I have  already confessed  that I have
little new information to offer.   In determining the question,
several other circumstances besides the mere temperament
 require to be considered.  A more or less  laborious mode
of life, for example, will require a more or less nutritious
   * Dr. Forbes in Cyclop. Pract. Medic, vol. i., p 693, foot-note. 
244      ADAPTATION OF DIET TO CONSTITUTION.
diet, whatever the original habit of body may be.   In like
manner, if any temperament be in excess, and we wish to
repress its predominance, the same kind of food  which is
suitable for it in a lower degree will no longer be applicable.
Thus, when the lymphatic constitution is predominant, and
our object is to diminish its ascendency and stimulate the
system to greater vigour, a larger proportion of solid nour-
ishing food, combined with increased exercise, will be pro-
per than if there were no such excess.  Where, on the other
hand, the  nervous or sanguine temperament preponder-
ates, a plainer and less exciting regimen will be necessary
than where the, constitutional tendencies are  more equally
balanced.
  The power we possess of modifying the constitution by
well-directed regimen is very great, and  only requires to
be sufficiently investigated to have due importance assigned
to it in conducting physical education.   This is well ex-
emplified  in the art of training,  where diet and exercise are
reduced to a practical science for the attainment of certain
results, and with remarkable success.   In the hands  of  a
trainer, the breathless and oppressed frame of a person over-
burdened  with lymph and fat speedily becomes converted
into an active, firm, and well-conditioned organization, ex-
hibiting a promptitude of action of both mind and body the
very opposite of its former  manifestations ; and  if such  a
change can be effected, by rigid adherence to rules, in the
course of two or three months, we may easily conceive the
degree of improvement which would follow the uniform ob-
servance of proper regimen and dietetic precepts in ordinary
society.   In improving the moral and intellectual as  well
as physical condition of the working-classes, the influence
of food, air, and exercise will  soon be discovered to pos-
sess a degree of importance of which at present scarcely  a
suspicion is entertained.  They constitute, in fact, the  very
foundation of systematic  education ;  and mere intellectual
cultivation will fail to produce its full beneficial results, till
the organization by which the mind operates be itself im-
proved by a treatment in harmony with its own constitution.
   If it be impossible for me to  communicate  sufficient in-
formation to enable each of my readers at once to determine
beforehand the kind of diet which is likely to suit him best,
it will give him at least some satisfaction to know that the
fulfilment of the conditions of healthy digestion, already 
       VEGETABLES AND SOUPS BAD FOR DYSPEPTICS.   245

explained, is of even greater importance than the selection
of the proper kind of food.  By observing personally, how-
ever, what kind of food agrees best with the stomach and
constitution, and  at the same time attending  to the laws of
digestion, the probability of causing mischief by an ill-select-
ed diet will  be greatly diminished.  When we refrain from
eating too much  and  at  unreasonable hours, and are not
conscious of any undue oppression or discomfort after our
meals, but, on  the contrary, feel  light or refreshed, and,
after a time, ready for renewed exertion, we may rest as-
sured that the food which we have taken is wholesome and
suitable for  us, whatever be its nature and general  effects.
Whereas, if, without committing any excess or other dietetic
error, we experience the opposite sensations  of oppression,
langour, and uneasiness, we may be just as certain that our
food, whatever  its general character  for lightness  and di-
gestibility, is not wholesome or suitable for  us under our
present circumstances.   So that, with a little care and
trouble, we shall rarely be at any loss to find out what we
ought  to  eat and what to avoid ; and, accordingly, it is
notorious  that  indigestion from a wrong choice of  food is
induced at least nine times by wilful  indulgence, for once
that  it occurs from errors originating in ignorance  alone.
If the proper quantity of food be not exceeded, and the other
conditions of digestion be  carefully fulfilled, no serious con-
sequences will  result from any  accidental mistake in its
selection.
  After the  full exposition of the laws of digestion given
in the first part of this work, I need hardly add that, al-
though there are very few articles of diet which a  person
in health,  and leading a sufficiently active life, may  not eat
with impunity,  there are,  nevertheless, some  which ought
to be preferred, and others which  ought to be avoided, by
those whose  digestion is impaired.  Thus, as we have seen,
vegetables are,  generally speaking, slower of digestion than
animal and farinaceous aliments,  and, consequently, when
digestion is feeble, are liable to remain in the bowels till
acetous fermentation takes place, and gives rise to  acidity
and flatulence.   Fat and oily meats are nearly in the same
predicament, and hence both form unsuitable articles of diet
for dyspeptics.   Soups and liquid food are also  objection-
able, both because they are ill adapted for being properly
acted upon by the gastric  juice and by the muscular fibrea
                          21* 
246    VEGETABLES AND SOUPS BAD FOR DYSPETICS.

of the stomach, and because they afford insufficient nour-
ishment.  From the former cause they frequently impair
the digestive functions; and from the latter they induce
diseases of debility which it is difficult to subdue.  Daily
experience furnishes examples of stomachic disorder from
eating  soups, especially  as  preliminary  to an otherwise
substantial dinner ; and the fatal epidemic which prevailed
a few years ago in the Milbank Penitentiary, was distinctly
ascertained to have  been partly caused by an insufficient
and too liquid diet.  It is common, indeed, to see heart-
burn and indigestion of recent origin cured simply by giving
up soups and vegetables,  and diminishing  the quantity of
liquid taken at breakfast and tea.
  When, from the state of health or other causes, chicken
tea, beef tea, veal broth, or other kinds of soup require to
be given, their digestibility will  generally be promoted by
the addition of bread or rice to give them consistency, and
by taking little  or no other food along with them.  Even
vegetables, when taken alone, are sometimes digested with-
out difficulty, where, if mixed with other substances, they
disorder the stomach.  Dr. Abercrombie mentions a very
remarkable instance of this kind in  a gentleman who " had
been for many years a martyr to stomach-complaints, sel-
dom a day passing in which he did not suffer greatly from
pain in his stomach,  with flatulency,  acidity,' and the usual
train of dyspeptic symptoms ; and, in particular, he could
not taste a bit of vegetable without suffering from it severely.
He had gone on in  this  manner for years, when he was
seized with complaints in  his head, threatening apoplexy,
which, after being relieved by the  usual means, snowed
such a constant tendency to recur,  that it has been neces-
sary ever since to restrict  him to a diet almost entirely of
vegetables, and  in very moderate  quantity.   Under this
regimen, so different from his former  mode of living, ho
has continued free from any recurrence of  the complaints
in his head, and has  never been known to complain of his
stomach."*   In this case,  however, both the very moderate
quantity of vegetable food to which  the patient restricted
himself,  and  possibly also the gradual adaptation of the
gastric juice to  the nature of the food,  had no small share
in the subsequent improvement of his digestion.
  Dr. Beaumont mentions, as a general result from his ex-
  * Abercrombie on Diseases of the Stomach, &c, 1st edit, p. 73. 
         VEGETABLE FOOD A CAUSE OF ACIDITY.      247

periments on St. Martin, that vegetable  food is slow of
digestion ; but it is much to be regretted that he gives the
particulars of only one or two trials, which lead to no very
important results.   In one of these already mentioned, St.
Martin ate " nine ounces  of raw, ripe, sour apples at  2
o'clock 35 minutes.   At 3 o'clock 30 minutes the stomach
was full of fluid and pulp of apples, quite  acrid,  and irrita-
ting the edges of the aperture, as is always the case when
he cats acescent fruits or vegetables."*  In another instance
ten ounces of raw cabbage were given, and  in  two hours
not a particle of it was to be found in the  stomach ; while,
on a third occasion, half a pound of raw cabbage, cut fine, and
macerated in vinegar, disappeared in little more than one
hour and a half!  If in the latter experiments the cabbage
were  really digested, and not merely  propelled  out of the
stomach into the intestine, we shall be forced to admit that
we have still much to learn concerning the digestibility of
different kinds of food, for the result is contrary to all ge-
nerally received opinions.   When vegetables are allowed,
great stress is commonly laid upon the necessity of their
being thoroughly cooked ;  and yet, according to these ex-
periments, raw  cabbage is very nearly as digestible as soft-
boiled rice or sago !   It is strange that Dr. Beaumont should
not have remarked this anomaly, which he seems not to have
done, since he neither attempts to explain it nor alludes  to
it as anything extraordinary.  My own  suspicion  is, that
the cabbage was not entirely digested, but had merely passed
through the pylorous into the intestine.
   Dr. Beaumont's testimony in favour of farinaceous ve-
getables is, however, more precise  and satisfactory.   In
some of his experiments  St.  Martin digested completely
a full meal of boiledrice, seasoned with salt, in a single hour.
 Soft  custard and boiled  rich sago, sweetened with sugar,
and taken in quantities of a pint each time, were disposed
of with nearly equal despatch, and " there was no acrimony
of the gastric   contents,  or smarting of the edges of the
 aperture, during their chymification, as  is usual in most
vegetable and farinaceous aliments ;" on the contrary, the
 sago " seemed peculiarly grateful to the  surface of the sto-
 mach, rendering the membrane soft, uniform, and healthy."t
   * Beaumont's Experiments and Observations on the Gastric Juice
 and the Physiology of Digestion. Reprinted with Notes by Andrew
 Combe, M.D.  Edinburgh, 1839, p. 259.
    f Beaumont's Experiments and Observations, &c., p. -2o7. 
248 PLAIN ANIMAL FOOD USEFUL IN WEAK DIGESTION.

In  these instances, it ought to be remarked, nothing else
was eaten at the same  time ;  so that the stomach was not
oppressed by quantity.
  In early life, when digestion is vigorous, the system ex-
citable, and the habits  peculiarly  active, a full  proportion
of vegetable and farinaceous  food  is proper and salutary.
Morning and evening  meals  of this description, prepared
with milk, or taken along  with it,  are very useful—animal
food being reserved for dinner alone.  But as age advances
and excitability diminishes, and perhaps also as habits of
activity and  exposure  to  the open air are  changed,  the
same proportion of  vegetable and  farinaceous food can no
longer  be digested so easily, and, therefore, ought not to be
continued.
  Pastry, rich cakes, puddings, and other articles contain-
ing much fatty or oily matter in their composition, are per-
haps the most  generally indigestible of all kinds of food,
and, consequently, ought never to be eaten when the tone
ef the  stomach  is impaired.   There are states, however, in
which  oily  articles seem to agree better than lean.   I have
seen very fat fried bacon, foT example, digested with ease
at breakfast, where even a small potato would have disor-
dered the stomach.   It is very difficult to afford any  expla-
nation  of the  fact, which, however,  is not uncommon.
Perhaps  it  is dependant on a  peculiar state of the biliary
secretion, for Dr. Beaumont  often remarked that the pre-
sence of bile in the stomach  facilitates the digestion of fat
and oily aliments, and  that, even  out of  the stomach, gas-
tric juice dissolves suet faster when a little bile is added to
the mixture than when the juice is pure.   He  mentions,
moreover, that he never found bile in the stomach, at least
during  health, except when food of an oily kind had been
eaten ; and, in accordance with this, I have generally no-
ticed that fried bacon agrees best with what are  called
"bilious "  subjects.  Still, however, the quantity must be
small,  otherwise it will prove injurious.
  Plain,  well-cooked animal  food, not too recently killed,
and eaten in moderate quantity with bread, rice, or roasted
potatoes, forms  one  of the most easily digested meals which
can be  devised for a weak stomach.  Sometimes, however,
potato  induces  acidity  and flatulence, and ought not to be
used.  Ve~nison and most kinds of game are very suitable
in the  same circumstances. 
EXPOSITION OF PRINCIPLES AIMED AT.       249
  In some  conditions of  the  system, where considerable
irritability prevails, and the mode of life is not sufficiently
active, red highly animalized meat proves too stimulating
although easy of digestion.  The same thing happens du-
ring recovery from illness; and hence fish, chicken, and
other white  meats which excite less and are digested more
slowly, are often allowable where beef, mutton, pork, &c,
cannot be taken with impunity.  For the same reason, white
and young meats  are the best adapted for the excitable
systems of the young.
  It would  be  easy to  fill many  pages with disquisitions
about the preference due to individual articles of food, were
such the purpose which I had in view.  But books devoted
to this  branch of  the subject  abound, and  are already  in
general  circulation ; and as I have nothing new to  add  to
what  is contained in them, and to the general .view given
in a preceding chapter, it would be making a needless de-
mand on the patience of the reader merely to repeat what
is to be  found in so many other works.   My object is the
exposition of practical principles rather than of minute
details ;  and my great aim is  to  enable  every intelligent
person to understand, not  only what digestion is, but the
laws by which it is regulated, so that he may know at once
why it is for his advantage to  adhere to one course of con-
duct in  preference to another in regard to it—whv, in dif-
ferent situations, diet requires to be modified in order  to
adapt it more effectually to the varying wants of the system
—and,  lastly, t'he circumstances or rules by which such
modifications ought to be determined.  If I have succeeded
in the attempt to explain any or all of these principles suf-
ficiently to render them susceptible of a practical application
by the reader, not only will  I  be greatly pleased, but the
advantage to him will  speedily convince  him that  I have
acted judiciously in forsaking the beaten path, and drawing
his attention to truths of still greater importance to his wel-
fare than those which are  most commonly treated of undei
the title of Dietetics. 
250
                    CHAPTER VI.
                       ON DRINKS.
Thirst the best guide in taking simple drinks—Thirst increased by
  diminution of the circulating fluids—The desire for liquidsgene-
  rally an indication of their propriety—Much  fluid hurtful  at
  meals—Most useful three or four hours later—The temperature
  of drinks is of consequence—Curious fall of temperature in tho
  stomach from  cold water—Ices hurtful after dinner—Useful  in
  warm weather, when digestion is completed and caution used—
  Cold water more dangerous than ice when  the body is overheat-
  ed—Tepid drinks safest and most refreshing after perspiration-
  Kinds of drink—Water safe for every constitution—Wine, spirits,
  and other fermented liquors too stimulating for  general use, but
  beneficial in certain circumstances—Test of their utility.
  On the subject  of drinks two questions naturally occur.
When ought we to drink ?  and, What ought we to drink?
On both I shall offer a  few very brief remarks.
  In the first part of this volume I  endeavoured  to show
that  the sensation of thirst is given for  the  express  pur-
pose  of impelling us to  take liquids whenever the wants
of the system  require  them,  and that,  in all  ordinary cir-
cumstances, we  cannot  have a  better  or  a  safer guide.
Such is the general case ;  but,  exposed as  we are to nu-
merous deviations from  the  intentions  of  Nature in our
ways of living, a  few precautionary  observations  may not
be without  use.   *
  The quantity  of fluid separated from  the blood  and
thrown  out of the system, in  the course of twenty-four
hours, by perspiration, exhalation from the lungs,  the  uri-
nary  discharge, and the  various  other  secretions, is very
great; and  were not the  loss as regularly supplied by the
ingestion  of liquid, either as  food or as drink, the blood
would speedily become so thick as to be unfit for  circula-
tion.  This actually happens in spasmodic cholera, in which
the  serum or watery portion of the blood  passes ^F through
the  bowels with such rapidity as to  cause the  entire sup-
pression  of the urinary secretion, and  in  which, conse-
quently, the urgency of  thirst  is almost always excessive.
In the healthy state, however, the loss of  fluid  is never
too  rapid, unless under severe exertion  or  exposure  to  a
very high temperature,  both being circumstances in which
it is well known that thirst becomes urgent in proportion
to the necessities of the frame.
  In  proof of the  sensation of thirst  being greatly depen-
dant upon the quantity  of fluid  circulating in the  vessels, 
             RULES FOR GRATIFYING THIRST.          251

Professor Dunglison, of Maryland, refers  to the fact, men-
tioned by Dupuytren, that he " succeeded in  allaying the
thirst of animals by injecting milk, whey, water, and other
fluids into their veins ;" and to Orfila's statement,  " that,
in his  toxicological experiments, he frequently allayed, in
this way, the  excessive 1 hirst of animals to which he had
administered poison, and which were incapable of drinking,
owing to the oesophagus having been tied.  He found, also,
that the blood of animals was more and more deprived of
its watery portions as the abstinence from liquids was more
prolonged ;"*  and hence the greater thirst naturally expe-
rienced under such circumstances.
   As a general rule, then, the desire for liquids will in it-
self be an indication of their propriety ;  but, in gratifying
it, we should be careful not to drink so fast  as either to
distend the stomach beyond proper bounds,  or to disturb
the progress of digestion by undue  dilution too soon after
eating.  Many persons, from habit rather than thirst, im-
pair  the tone of the stomach by drinking largely  during
or immediately  after meals, and thus relaxing the mucous
coat,  and probably affecting the quality of its secretions.
If the gastric juice be greatly diluted by extraneous  fluids,
it is  natural to suppose that its  solvent power must  be di-
minished ; but, whether this explanation be sound or not,
the practice of drinking frequently is certainly hurtful, and,
therefore, we ought to avoid it.
   Experience  proves that a  moderate  quantity of liquid
during a meal  is beneficial; and  if we drink little at a
time, the risk of  exceeding the proper limit will be very
small.  Dyspeptics, however, ought to be on their  guard
against taking  too much, as they are apt to be misled by
uneasy sensations in the region of  the stomach, which are
relieved for a moment, but  afterward aggravated,  by the
free  dilution of the food.   Those  also who live well,  and
are in the habit of  taking wine daily whether the system
requires it  or  not,  often fall into the error  of excessive
indulgence in liquids to mitigate the thirst and irritability
which the unnecessary use of stimulus never  fails  to in-
duce, especially at night. The continual dilution, however,

  * See Professor Dunglison's Elements of Hygiene, p.  324, in
Which the reader will find a great variety of very useful information
on all the branches of the subject.  The remarks on the different
kinds of food and drink are among the best which I have met with. 
252         RULES FOR GRATIFYING THIRST.
 adds to the mischief, by increasing the debility of the stomach,
 and, as pointed out in the chapter on Thirst, the only effec-
 tual remedy is to adapt the diet and regimen to the real wants
 of the constitution.  Except in disease, a continually recur-
 ring thirst must proceed from mismanagement, and it is to
 be satisfied by an improved and rational regimen, and not by
 oceans of fluid, which only weaken the stomach still more,
 and aggravate the craving they  are meant to cure.
   The opinion is very  prevalent, that mild drinks may be
 taken with most advantage about three or four hours after a
 solid meal; and, certainly, the almost universal use of tea
 or coffee about that time appears to sanction its soundness.
 Theoretically, too, we might expect this result; for diges-
 tion is then nearly over, and any food  remaining in the sto-
 mach is already in a fluid state.   Many objections, however,
 have been made to both tea and coffee as an evening beve-
 rage, but most of them  seem to  me to apply to their undue
 quantity and strength rather than to  their temperate use.
 When made very strong, or  taken  in large quantity, espe-
 cially late in the evening, they not  only ruin the stomach,
 but  very  seriously derange  the health  of the  brain and
 nervous system.
   The question of drink is of little importance as  regards
 breakfast.  During the  night the chief  expenditure of the
 system—by perspiration, urine, and exhalation from thelungs
 —is of a fluid nature, and hence there is a marked  and ge-
 neral preference of fluids as part of our first meal.   In this
 country, accordingly, tea, coffee, and chocolate are in almost
 universal use for breakfast, and no other liquid is required
merely as drink.  If, from the mode of life or other causes,
thirst be excited  in the forenoon, no valid objection can
be urged against its moderate and reasonable gratification.
  The temperature at which  liquids are taken  is a matter
of perhaps greater consequence than it is usually considered.
As regards the teeth, we have already seen that  either very
cold or very hot substances coming  into contact with them
are apt to be injurious.   As regards the stomach, the same
principle holds true ; and when we  consider the multitude
and intricacy of its nervous connexions with other vital or-
gans, we can scarcely be surprised at  even sudden death
 Deing frequently caused by drinking ice-cold  water when
 the body is weakened by exhaustion and profuse perspiration.
 Of the various subjects connected with digestion on which 
         TEMPERATURE OF DRINKS CONSIDERED.      25$

T)r. Beaumont has thrown light by his experiments on St.
Martin, this is  one of the  few which  he has omitted to
investigate with his usual diligence and accuracy ;  a cir-
cumstance  which is the more remarkable, because an inci-
lental observation of his own seems, from its singularity, to
lave been well calculated to direct his attention to its con-
lideration.   On the occasion alluded to,  when  a gill of
water, at the temperature of 55° Fahr., was received into
the empty stomach, in which the thermometer previously
indicated a heat of 99°, Dr. Beaumont remarked that  it
immediately diffused itself over  the interior  surface, and
brought down the temperature to 70°, at which it stood for
a few minutes,  and then began again to rise very slowlv.
It was not  till thirty minutes had elapsed, and all the water
been for some time absorbed, that the mercury regained its
former  level of 99°.  This  is an important fact, and it  is
curious  that Dr. Beaumont did not think of following it up
by a regular series of experiments, to ascertain the effects
of cold and hot drinks on the progress of digestion and on
the general system.   It is well known, for example, that a
copious draught of cold water, taken in a state of perspira-
tion and fatigue, is often instantly fa'tal; but its  operation
has never been satisfactorily explained.   The above experi-
ment, however, throws some light on it; for if a single gill
of water at 55° (which is not by any means a low tempe-
rature).is able to reduce the heat of the stomach in a mo-
ment by no less than twenty-nine degrees, when  neither
fatigue  ner perspiration is present to add to its effect, the
influence of a large quantity, such as is usually drunk by
harvest-labourers and others who die of it, and  at  a still
lower temperature, must undoubtedly be much more power-
ful and permanent, especially when the bodily energies and
means of resisting the shock are impaired by  previous labour
and exhaustion under a burning  sun.   In these cases the
shock necessarily Arising from such  a sudden and  exten-
sive fall of temperature is greatly increased by the position
of the stomach in the very centre of the vital organs, to all
of which it is most intimately linked by  the numerous ner-
vous connexions given for the express purpose of extending
jiie range and direction of its sympathies.
   Keeping in mind the great depression  of  temperature
paused  by swallowing so small a quantity of cold water, and
also the ascertained fact that a heat of about 100° is requisite
                           22 
854          ICES HURTFUL AFTER A MEAL.
for healthy digestion, we shall have no difficulty in acconnt-
ing for the frequent injurious  consequences  arising from
considerable quantities of ice-cream being hastily eaten, as
they  often  are, at  the end of a substantial dinner.  The
immediate effects of the rapid abstraction of heat to which
they give rise in the stomach, are the instantaneous contrac-
tion and diminished action of its bloodvessels, the conse-
quent stoppage of the gastric secretion, diminished sensibility
of its nerves and muscular  fibres, and, lastly, disturbance
of the heart and neighbouring vital organs, both by sympathy   ,
and by the direct abstraction of their heat.   Such, at least,
are the consequences which flow from  the application of
cold to parts exposed to observation,  and partially  verified
by Dr. Beaumont in the case of the stomach ; and if  the
analogy holds throughout, as  there is every reason to  believe,
we cannot wonder  that the free use of ice-cream at the end
of a  good dinner or supper  should retard  and even arrest
digestion in a  person delicately constituted.
  In thus condemning the free use of ices at the end of  a
substantial meal, I do not, however, mean to say that a few
tea-spoonfuls of them, eaten slowly, and allowed to acquire
a higher  temperature before reaching  the stomach, will do
permanent injury  to a person  in health and  in the enjoy-
ment of sound digestion.  Many eat them in  this way and
are little the worse; partly  from the subsequent reaction,
as in bathing,  being sufficient to counteract the depressing
influence, and  partly from a person in vigorous health being
able  to throw off causes of  disease from which those who
are less robustly constituted suffer severely.  My belief,
however, is, that the tendency of ices, taken  in such cir-
cumstances, is to produce  mischief.   A healthy person, for
example, may possess vigour enough to escape injury from
immersion in cold water, caused by the ice giving way when
•kating ; but as well might  it be inferred, on that account,
that a similar immersion would be generally innocuous, and,
even salubrious, as that all  may safely eat ices  freely  be-
cause a given  individual has done so  with impunity.   Dr.
Beaumont's experiment with the cold water shows clearly
that the effect is to  lower the vital tone of the stomach ; and,
guch being the case, those whose digestion is  weak ought
to be careful against impairing it still  farther by the use of
ices.   In some instances, however, it is not improbable that
they help to neutralize the bad effects of hot  soup, and
Other dishes eaten at too high a temperature. 
           ICE USEFUL WHEN PROPERLY USED.        255

  The use of cold or iced water in hot weather and in warm
climates, when digestion is not going on and exhaustion is
not present, is so far from  being  necessarily hurtful, that,.
with proper caution, it may prove both grateful and refresh-
ing.  In Italy, accordingly, ice is considered  so much a
necessary of life in summer, that in Naples and other places
the confectioners are punished by a fine if they allow their
supply to fall  short.   In Virginia, too, where, we are told
by Professor Dur.glison, it was very common some years
ago for the  labourers in the harvest-field to be killed by
drinking copiously of spring-water while overheated, case3
of death have become extremely unfrequent since the cus-
tom was introduced of  supplying  them with ice.  When
water was taken, it was always hastily and in large quan-
tity, so that the immediate effect on the system was greater
than could possibly  arise  from  the small quantity of ice
which is  required for quenching thirst.  The very slow-
ness, indeed, with which ice melts, not only prevents much
being taken, but causes the water procured from it to reach
a higher and  safer temperature before  it arrives at the
stomach.*  Hence, when  ices are taken, the more slowly
they are eaten, the more refreshing and salubrious will they
become, because the  less violent will be their action  upon
the nerves, bloodvessels, and membranes of the stomach.
From the close sympathy  existing between the stomach
and the  skin, a single tea-spoonful of  ice-cream, suddenly
swallowed when the body is weak and perspiring, will pro-
duce as  instantaneous  a sense  of chill as a pail of cold
water dashed  over the  surface ;  and, on account of this
very power over the vital actions of the stomach, ice has
of late been cautiously and beneficially  prescribed to subdue
inflammation  of that  organ.
   Liquids, such as  soup, tea, and coffee, taken  at a very
 high temperature, are  also injurious,  but not in the  same
degree-.   They relax the  mucous membrane  and weaken
 the action of the  muscular coat, and  in so far tend to im-
 pair digestion.  The fittest temperature for both solid and
 liquid food is perhaps about the natural heat of the body,
 or a little above 100°.   Dr. Dunglison, however, and  some
 other physiologists, regard hot fluids as  stimulating to the
 stomach, and,  therefore, conducive to digestion; but  he
 admits that debility is their ultimate effect.
           * Dunglison's Elements of Hygi&ne, p. 331. 
256       TEPID DRINKS SAFE AND REFRESHING.

  When great thirst  has  been excited, either by bodily
labour or by external heat, it will generally be more effec-
tually as well as safely  quenched by drinking moderately of
tepid than  of cold fluids.   A tepid draught—a cup of  tea,
for example—produces no disturbing action in the stomach,
and, being immediately absorbed, supplies  the  deficiency
of liquid without changing the  balance of the circulating
fluids, thus relieving thirst very much in the same way as
Dupnytren did by  injecting tepid  water into  the veins ;
whereas cold drink, by the suddenness  of its impression,
disturbs the balance of the circulation, and excites a degree
of reaction which increases the original discomfort.  If the
system is at the same time weakened by fatigue, cold drinks
are always injurious.
   Of late years a change in the treatment of horses in this
respect has taken place.  Formerly it used to be considered
dangerous to give water to a horse in a state of perspiration.
Now, however, it is a common practice  to ai'low post and
stage-coach  horses a  little water  before  their run is com-
pleted, however warm they may be : but, in the first place,
the quantity allowed is small, and is always given before
the  strength is exhausted ; and, in the  second place, the
excitement of the  subsequent exercise  prevents any con-
siderable disturbance in the balance of circulation, and thus
ensures the safety  of the animal.  If even the same mode-
rate quantity were  given at the end of the stage, and the
horse were then allowed to rest, inflammation would almost
inevitably result.
   The  same principle applies to the human  frame, and af-
fords an easy explanation of the occasional instances we see
of persons heated by exertion drinking cold water without
injury.   If the exertion have been merely sufficient to pro1
duce excitement without fatigue, and heat without debilita-
ting perspiration, and especially if it be resumed after the
draught, little or  no harm will ensue.   But if exhaustion or
fatigue have been induced, and the individual be allowed to
drink freely of the  cold water and then rest,  the probability
of mischief resulting from it will be greatly increased. Many
accidents  result  from  losing  sight of  this distinction, and
from acting alike in circumstances so essentially different.
   On the  subject of the  kind of drink  which ought to be
 taken, a great deal might be said, were it necessary to dis-
 cuss here  the  qualities of all the liquors that are in use. 
            EFFECTS OF FERMENTED LIQUORS.         257

But as my purpose is very different, a few general remarks
will be enough.
   Water  is a safe drink for all  constitutions, provided it
be resorted to in obedience to the dictates of natural thirst
only, and  not of  habit, and with the precautions already
pointed out; but, unless the desire for it is felt, there is no
occasion for  its use during a meal, for the mere purpose
of obeying a general rule.   Toast and water, whey, beer,
barley water, aerated and soda water, and other liquids of
a similar  kind, which  are little stronger than pure  water,
may be used, according to the same general  principle, by
those who prefer them and find them agreeable to the sto-
mach.   But with regard to such fermented liquors as porter,
ale, spirits, and wine, much greater restriction is necessary,
because  much good or  evil may be done by them  when
properly  or  improperly administered.
   The primary effect  of all distilled and fermented liquors
is, to stimulate the nervous system and quicken the circula-
tion.   In all conditions, therefore, in which the  action of
these requires to be increased or supported, they are calcu-
lated to be useful ; and, on the contrary, where it requires
to be soothed and abated, they are sure to be prejudicial.
To show the utility of this  principle as a standard, we shall
notice a few of its applications.
   Among the higher classes it is common to give children
an allowance of wine every day from a very early age.   To
determine the propriety of doing so, let us examine what
is then their constitutional state.
   In infancy and childhood  the circulation is rapid and
easily excited, and the nervous  system is strongly  acted
upon even by the slightest  external impressions.  Hence
slight causes of irritation readily excite febrile and convul
sive disorders.  The object of the parent, therefore, is not to
stimulate, but  rather to abate, nervous and vascular action.
Wine, accordingly, is not  only unnecessary, but positively
detrimental to children, and it is wrong to  accustom them
to it.  There are individual children, no doubt, who are sg
imperfectly and  sluggishly constituted as to require  some
stimulus to rouse the system to healthy action, and to whom
wine is beneficial as a medicine.   But these are the excep-
tions to the  general rule, and to them it should  be given
only under medical sanction.
   In vouth the natural tendency of the constitution is still
                          22* 
258    WHEN ARE STIMULATING LIQUORS USEFUL T

to. excitement; and, consequently, as a general rule, the
stimulus of fermented liquors is injurious.   During  rapid
growth, however, the animal  functions are sometimes so
enfeebled by the great demands made upon them, that not
only a full supply of nourishing food, but also an allowance
of wine and  malt liquor, is required for a time to sustain
their  energy.   In this case the  beneficial influence of the
fermented drinks is apparent, by their giving tone to the
system without raising the pulse or increasing nervous sen-
sibility ; but  whenever any of these effects is produced,
their employment ought to  be discontinued.
  In mature  age, when digestion is good and the system
in full vigour, if the mode of life be not too exhausting, the
nervous functions and general circulation are in their best
condition, and require no stimulus for their support.  The
bodily energy is  then  easily sustained  by nutritious food
and a regular regimen, and, consequently, artificial excite-
ment only increases the wasting of the natural strength.
Where, however, the system has been long accustomed to
the use of wine, it will, in general, be better to leave it off
gradually than to make a sudden change.  In old age, when
the powers of life begin to fail, moderate stimulus may be
ttsed  with evident advantage.
  If  it be said that this doctrine amounts to a virtual pro-
hibition of wine and stimulant liquors, I admit at once that,
where the  whole animal functions go on healthfully and
energetically without them, their  habitual use is, in my
opinion, adverse to the continuance of health.  But there
are many constitutions so inherently defective in energy, as
to derive benefit from a moderate daily allowance of wine :
and there are many situations in which even the healthiest
derive additional  security from its occasional use.   If, for
example, a healthy person  is exposed to unusual and con-
tinued exertion in the open air, or to the influence of anxious
and depressing watchfulness, a  moderate quantity of wine
along with his  food may become the means of warding off
actual disease, and enabling him tobearupuninjurcd, where
without it he would  have given way.   This preservative
influence has been so often experienced, that it is impossi-
ble to deny its reality.
   While, then, I  consider stimulating liquors of eveTy kind
as both useless and hurtful, where without them the system
is healthful and  energetic, I  can see no reason why their 
WINE PREFERABLE TO SPIRIT8.         259
temperate use in circumstances of an opposite nature ought
to be denied.   Many weak constitutions and many invalids
are benefited by wine, and all that can reasonably be de-
manded is, that it  shall not be abused.
   Continued and  severe  exertion, whether of body or of
mind, often exhausts the system so much as to render the
temporary use of wine, and even of spirits, not only innocu-
ous, but positively beneficial;  but in these cases they should
be considered as medicines, and care ought to be taken not
to carry the stimulus too far.  That, in some circumstances,
stimulus is really required, is accordingly shown by the  ease
with which the system bears its effects.   I have known a
delicate lady, during recovery from fever,  take to the extent
of a bottle of Madeira in  twenty-four  hours, without  pro-
ducing the least undue excitement of either the mind or the
pulse, but rather the contrary—it soothed  the  mind and
reduced the pulse  ; and  this 1  take  to be the true test of
its propriety in all  circumstances.
  The same principle explains the  well-known fact, that
many sportsmen, who, while living  a sedentary life in town,
are easily  affected  by even a small quantity of spirits, yet
bear triple the quantity, with  apparent  impunity, under the
influence of inspiriting exercise  in a pure mountain-air  : on
resuming their  former  habits, the spirits again affect them
as readily  as before.
  As a support to the system in  cases  which require it,
wine, is in general, far preferable to spirits of any description.
The former, when  seasonably used, communicates a more
healthful and permanent tone to the frame ; while spirits
impart a strong and unnatural stimulus, which is sooner or
later followed  by collapse and debility—and hence the in-
cessant craving for more when the system has once been
accustomed to them.  Ardent spirits, therefore, ought to be
used only as a medical remedy.   At present, however, this
is  so  far from  being the case, that they are resorted to on
all  occasions, afflictive and convivial, as if they were a
specific  against every evil.  Among the poor  especially,
whiskey or gin  is considered a sovereign  remedy for every
disease.  Even to infants it is administered with a reckless.
ness which savours strongly  of barbarism, and the  conse-
quences are, as might be expected, deplorable.  Among the
higher classes, too, brandy and strong stimuli are in more
frequent use than  they ought  to  be ; and medical men 
260      EFFECTS OF SPIRITS ON THE STOMACH.
 should be on their guard against directly or  indirectly en'
 couraging, in their patients, a practice so utterly destructive
 to  both physical and  moral happiness.  For, in  some  in-
 stances, it is to be feared that the stimulant bitters and anti-
 spasmodics, so generally had  recourse to in indigestion and
 nervous diseases, have had an  unsuspected share in the
 formation of a habit of intemperance.
   Of late years great exertions have been  made, both in
 this country and in America, to warn the public against in-
 dulging in the use of ardent spirits ;  and powerful medical,
 as  well as moral, facts and arguments have been adduced
 to demonstrate the unspeakably greater advantages of tem-
 perance.  These efforts have been followed with astonish-
 ing success, and the good which has been already effected
 is immense.   In  Ireland especially, the reformation in the
 habits and morals of the people  under the total abstinence
 system so energetically and eloquently advocated by Father
 Matthew, almost surpasses belief from its extent and uni-
 versality, and must be highly gratifying to every philanthro-
 pic mind.  It  is  probable, however, that the good  thus
 effected would be still farther increased and rendered more
 permanent, if  we did not confine ourselves  so exclusively
 to  the  mere inculcation of  abstinence  from intoxicating
 liquors, but concerned ourselves  more  in improving the
 general character, as the surest road  to reformation, and in
providing resources by means of which the nformation, when
 once effected, may  be fully confirmed.   The temperance
 which  is produced  by elevation  of mind and an improved
 State of moral feeling, will be not only much more beneficial
 in its consequences, but infinitely more proof against temp-
 tations, than that which is observed merely in fulfilment of
 a vow ;  and unless something be made to come in the place
 of the  enjoyment which  is withdrawn, the danger of a re-
lapse will continue to/be great.   The importance of this
principle is perhaps not sufficiently recognised in the other-
wise valuable labours of Temperance  Societies.
  Many  persons  imagine that spirits, taken in moderate
quantity, cannot be injurious, because they feel no immtdi/tte
 bad effects from their  use.   If the fundamental principle
which I have advanced is sound, and if all the functions of
the system are  already vigorously executed without the aid
of spirits, their use can  be followed  by only one effect—
morbid excitement;  and it is in vain to contend agdinst this 
         EFFECTS OF SPIRITS ON THE STOMACH.       2f>i

obvious truth.   The evil attending their  unnecessary use
may not be felt at the moment, but, nevertheless, it is there ;
and for demonstrative proof of the fact we are again indebt-
ed to Dr. Beaumont.   On examining St. Martin's stomach
after he had been indulging freely in ardent spirits for several
days, Dr. Beaumont found its mucous membrane covered
with erythematic (inflammatory) and aphthous (ulcerous)
patches, the secretions vitiated, and the gastric juice di-
minished in quantity, viscid and unhealthy ; although St.
Martin still complained of nothing, not even of impaired
appetite.  Two days later, when the  state of matters was
aggravated, " the inner membrane of the stomach was un-
usually morbid, the erythematic  appearance more extensive,
the spots more livid than usual; from the surface of some
of them exuded small drops of grumous blood ; the aphthous
patches were larger and more numerous—the mucous cover-
ing thicker than common,' and the gastric  secretions  much
more vitiated.   The gastric fluids extracted were mixed with
a large proportion of thick ropy mucus, and a considerable
mucopurulent discharge  slightly tinged with blood, resem-
bling the discharge from the bowels in some cases of dysen-
tery.  Notwithstanding  this diseased appearance of the
stomach, no very essential aberration of its functions was
manifested.   St. Martin  complained of no symptoms indi-
cating  any general derangement of the system, except an
uneasy sensation and a tenderness at the pit of the stomach,
and some vertigo, with dimness and yellowness of vision,
on stooping down and  rising again ;  had  a  thin yellowish
brown coat on his tongue, and his countenance was rather
sallow ; pulse uniform and  regular, appetite good ;  rests
quietly, and sleeps as usual."*
  I have marked part of this quotation in italics, because it
cannot be too attentively considered by  those who contend
that the stimulus of spirits is not injurious to the stomach
or general health, unless where the mischief shows  itself
by palpable external signs.   Here we have  incontestable
proof, that  disease of the stomach was induced, and going
on from bad to worse, in consequence of  indulgence in
ardent spirits, although no  prominent symptom made its
appearance, and St. Martin was, in his general habits, a
healthy and sober man.   And  if such be  the results of a
  * Beaumont's Experiments and Observations, &c., reprinted by
Andrew Combe, M.D., p. 250. 
 262           STATE OF STOMACH IN FEVER.

 few days of intemperance in a person of a sound constitu-
 tion, it is impossible to deny that continued indulgence must
 be followed by more serious evils, whether these show them-
 selves from the first by marked external signs or not
   After a few days of low diet and the use of mild diluents,
 the coats of St. Martin's stomach were seen to resume their
 healthy appearance ; the secretions became natural, the gas-
 tric  juice clear and abundant, and the appetite voracious.
 Dr. Beaumont adds, that, in the course of his experiments,
 diseased  appearances of a similar kind were frequently
 observed—generally, but not always, after some appreciable
 cause.   " Improper indulgence in eating and drinking has
 been the  most common precursor of these diseased condi-
 tions of the coats  of the stomach.   The free use of ardent
 spirits, wine,  beer, or any intoxicating liquor, when  conti-
 nued for some days,  has  invariably produced these morbid
 changes.   Eating voraciously or to excess, swallowing food
 coarsely masticated or too fast," " almost invariably produce
 similar effects, if repeated a number of  times in close suc-
 cession."  (P. 252 )   These observations require no com-
 ment ; their practical bearing must be obvious to all who
 are willing to perceive it.
   Dr. Beaumont had  also frequent occasion to remark, that,
 when stomachic disorder, attended with febrile symptoms,
 was present, the mucous coat of the stomach presented dis-
 tinct appearances  of disease.  He frequently saw it, for ex-
 ample, red, irritable, and dry ;  and, on the food touching it,
 no gastric juice exuded, and, consequently, any  food taken
 lay long  undigested.   But after the  diseased  action was
 subdued by  regimen and medicine, the  gastric juice again
 flowed readily, and digestion went  on as vigorously as be-
 fore.  Even anger and violent  mental  emotions sometimes
 produced  these appearances, and gave rise to temporary
 indigestion.   These observations show the futility, not to
 say mischief, of administering food during fever and other
 diseases by way of supporting the strength, when,  from the
 deficiency of the gastric juice, it cannot be digested, and
 can only add to the existing irritation.    In this  state, how-
 ever, bland fluids are appropriate;  because they allay irri-
tation, and are almost entirely  absorbed, without requiring
to be digested.
  The condition of the stomach above  described, and the
consequent failure  and vitiation of the gastric secretion, in- 
EFFECT OF DRAMS.
263
duced  by drinking ardent spirits, and by general intempe-
rance, explain at once the miserable digestion and impaired
appetite of the habitual drunkard ;  and it would be well for
those who  are in  danger of becoming the victims of the
habit, were they early impressed with some of these stri-
king and important truths.
  If it be asked whether I go the length of proscribing all
fermented liquors,  from table-beer upward, I  answer that I
do not;  I merely  mean  that, where the general health is
perfect without them, they ought not  to be taken, because
then their only effect is  to produce unnatural  excitement.
But  wherever the  constitution or health is so  deficient, or
the exertions  required by the mode of life are so great, that
the  system cannot be sustained in proper vigour  without
some additional stimulus,  I would  not only sanction, but
recommend the use of either wine or such other fermented
liquor  as should be found by  experience to  support the
strength, without  quickening the circulation,  exciting  the
mind, or disordering the  digestive functions.   If, however,   0
any of these effects be produced, I would consider its occur-
rence as a proof that the stimulus is  inappropriate, and can-
not be too soon discontinued, or at least diminished to 3uch
a quantity as  shall be consistent with the ordinary action
of the animal functions.
  It may be  alleged  that a glass of brandy  after a heavy
dinner facilitates digestion, and, therefore, cannot do harm.
I admit  at  once, that, when we eat too much, or fill the
stomach with indigestible food,  a dram of  brandy, from its
temporary stimulus, enables us to get rid of the load sooner
than we  could do without it.  But  it seems to me.that a
far wiser plan would  be, to abstain from  eating what  we
know to be oppressive to the stomach ; and  that by this
means we  shall attain our end infinitely better than  by
first  eating a heavy meal and  then taking a stimulus, the
efficacy of  which  is  diminished by every repetition of its
use.   If we were  compelled to  exceed the bounds of mo-
deration in eating, there would be some  apology  for our
conduct. 
264
                   CHAPTER VII.
      ON THE PROPER REGULATION OF THE BOWELS.
Functions of the intestines—The action of the bowels bears a na-
  tural relation to the kind of diet—Illustrations—And also to the
  other  excretions—Practical  conclusions  from  this—Different
  causes of inactivity of bowels—Natural aids to intestinal action—
  General neglect of them—Great importance of regularity of
  bowels—Bad health from their neglect—Especially at the  age of
  puberty—Natural  means preferable to purgatives—Concluding
  remarks.
  Having now taken a general view of the objects, nature,
and laws of digestion, and of the structure  and rriode of
action of the various organs concerned in its performance,
and made ourselves acquainted  with the principles on which
our conduct ought to be regulated, so  as to second the in-
tentions of Nature for our welfare and happiness, I have
only to  add a few practical remarks on  the proper manage-
ment  of the  bowels, and then conclude.
  The proper uses of the intestines are, as we  have seen,
to serve, 1st, for the performance of  ehylification ;  2dly,
for the  absorption of the  nutritive chyle ; and, 3dly, as  a
reservoir for  the  indigestible residue  of the food, and  an
outlet for both it and  the effete  matter which requires  to
be thrown out of  the  general  system.  The processes  of
ehylification  and  absorption having been treated of in  a
former chapter, it  is in the last capacity only we have now
to consider the intestinal canal.
  Besides the bowels, there are  several other channels by
which the waste materials of the  body pass out.   The most
important of these  are the skin, the lungs, and the kidneys ;
and in certain circumstances, where the action  of the one
is impaired  or repressed,  the  natural  alliance subsisting
among their respective functions, enables the rest to come
to its assistance, and  even for a time  to supply its  place.
Thus, when, by continued exposure to  cold, the exhalation
from the skin is much diminished, the blood is thrown  in
upon  the internal organs in larger quantity, and, as  a con-
sequence, the urinary secretion and the exhalation from the
lungs are both increased, and full relief to the system is
temporarily obtained.  During hot weather, on the  other
hand, when  the  skin is  in high action and perspiration
flowing freely, the urinary  secretion  is  greatly lessened.
The same principle applies equally to the case of the bowels;
and hence the sudden application of cold to the surface of 
        N THE PROPER REGULATION OF THE BOWELS.   265

the body, and consequent suppression of perspiration, often
increase the intestinal secretions to such an amount as  to
induce  bowel-complaint.   On the other hand, the excited
action of the bowels by laxatives tends equally to diminish
.the activity of the skin; and hence, indeed, one source  of
the cooling effect of saline purgatives administered in fever
and inflammations.
   The  bowels  being  thus the outlet  of  the indigestible
portion of the food, and of waste matter from the system,
it follows that in health their action ought to bear a rela-
tion . to the kind of aliment used, and  to  the state of the
other excretory functions  ;  and,  consequently, that what
may constitute healthy action at one time, and in  one indi-
vidual, may be very far from presenting the same character
at another  time, and in a different individual.  If, for ex-
ample, a person be fed chiefly on milk,  rice, or farinaceous
aliment, which  is almost  entirely appropriated to the pur-
poses of nutrition, and leaves very little residue, the bow-
els, having little to throw  out, will naturally  act  seldomer
and less fully than when the diet consists chiefly of bulky
and innutritious vegetables, which leave a  large portion of
indigestible matter to be  evacuated.   Most persons are
aware of the difference of effect between the two kinds  of
diet, but, from not being acquainted  with  the principle  on
which it depends, are apt  to conclude that, because in the
first case the bowels act  less,  therefore they ought to  be
assisted by laxatives.   The inference,  however, is  by  no
means necessarily sound ; because the diminished  intestinal
action consequent on an exclusively farinaceous diet is then
the natural and healthy result*;  and accordingly, where such
diet is required, and is not used in excess, the mere costive-
ness  is  attended with no  injury to the  constitution.   The
proper  conclusion  to be drawn from it is,  that the perma-
nent  and  exclusive  use  of  concentrated  food is  not  in
harmony with the structure and functions of our digestive
and assimilating  organs,  and  that,  therefore, instead  of
continuing their use, and merely resorting  to purgatives to
excite  an action for the removal of a  residue which does
not  exist,  reason  requires that  we should  select a diet
better adapted to the constitution and laws of the organiza-
tion by which it is to  be acted  upon.
   The same remark applies to those who are accustomed
to dine chiefly  on  animal  food, and rice or bread, without
                            23 
266       THE ACTION OF THE BOWELS BEARS A

any sufficient admixture of herbaceous or other innutritioue
substances.  If, in such  circumstances,  the aliment  ia
almost entirely converted into nourishment and absorbed,
it follows, as a  matter of necessity, that  little  will  remain
to be thrown out of the body, and that the bowels will act
less than with a different kind of diet.   If the  state of the
constitution at the time be  such as to require the exclusive
use of this kind of aliment, forced action of the bowels by
purgatives  will not be needed, because their slowness will
be  natural  and healthy.  But if it be  not, then the  proper
remedy is, not to excite the bowels by irritating purgatives,
but to remove  the cause  of the intestinal inactivity  by
changing the system of diet.
  It may be answered to  this, that  there are many in-
stances in which the stomach is unable to digest any vege-
table or innutritious food, and in  which,  consequently, the
diet cannot be altered without injury.   I  admit that, in the
present state of society, where  the  laws  of  the  animal
economy are so generally  disregarded, cases  of this  kind
are common; but their number would be greatly reduced
if  a proper  mode of life were systematically adopted, and
that regard paid to the conditions of health which their in-
trinsic importance deserves.  There  are  very few indivi-
duals who, when in health,  and with the  aid of a proper
regimen, cannot digest aliment suited to the  natural con-
stitution of the stomach and bowels; and when such cases
do  occur, they constitute exceptions  to  the general  rule,
and must, of course, be  treated either by the use of laxa-
tives, or  such other  remedies as  the circumstances  may
require.
  As the frequency and  amount of the intestinal evacua-
tions  may  thus vary according to  the nature of  the  diet,
without necessarily involving aiiy  disturbance of health, so
may they also vary according to the state of the other ex-
cretions ;   and  hence, again, is evident  the absurdity of
considering the same standard  as applicable  alike to all
persons, times, and circumstances.  If, from continued ex-
ertion, perspiration is kept unusually  active, the excretion
from the bowels may be proportionally diminished, not only
without injury,  but  even with advantage to the  health ;
because, if the  same waste were to go on by the bowels as
before, and the increased exhalation from the skin  also  to
continue, the system  would speedily become reduced.  In 
        NATURAL RELATION TO THE KIND OF DIET.    267

consumption, for example, exhausting bowel-complaint and
profuse perspiration are frequently observed to alternate,
and whatever remedy is given  to check the one generally
aggravates the other.   But if both were to run their course
together, instead of singly, how much more rapidly would
the system be undermined !
  From this relation between the different excretory func-
tions  it follows that,  when  sluggishness of the bowels is
induced by excess  in another excretion, the first step ought
to be  to remove or diminish the unnatural stimulus which
has occasioned that excess, before  attempting, by means
of purgatives, to force the bowels  to act.  If the cause
which has produced the deviation from the due proportion
of the excretion be left unabated, the only effect of strong
laxatives will be, not to relieve, but to irritate and weaken.
  The mere fact of the bowels not being emptied so fre-
quently as usual,  is, therefore, when taken by itself, no
evidence that they ought  to  be stimulated by medicine.
Before coming to this conclusion, we ought to determine
clearly whether the diminished action results from morbid
sluggishness of the intestinal canal, or is the natural result
of an accidental change of diet, or temporary excess in the
other excretions ;  because the remedy which is appropriate
and efficacious in  the one case, may be  altogether inappli-
cable  to the  other.    Where  it  arises entirely  from  the
aliment leaving little residual matter to be thrown out, the
health may suffer  from the  diet being inappropriate, but it
will not suffer merely from the diminished action of  the
bowels.   Whereas, when the diet is of the ordinary mixed
kind, and the costiveness proceeds from  morbid inaction,
then  general derangement of the  system will be induced,
unless the bowels be  attended, to and their natural action
restored.   This distinction  ought never to be lost sight of.
   Judging from the prevalent notions on the subject, from
the universal reference of all kinds of bad health to derange-
ment of the stomach and bowels as their source, and  from
the scarcely  less  universal use of purgatives as remedial
agents, one would be  apt to suppose  that, to ensure health
and long  life, nothing more was required than to procure,
no matter by what means, an intestinal evacuation regularly
 every day ; and the  inference would, to a certain extent,
 be confirmed by the acknowledged extensive utility of laxa-
 tive  medicines.   The real state of the case, however, is 
 268     DIFFERENT CAUSES OF INACTIVE BOWELS.

 not quite so simple ; and as it is of importance that it should
 be understood, I shall attempt to explain it as clearly as I
 can.
   We have seen that inactivity of the intestinal canal may
 arise from the use of too concentrated aliment, and from
 excess in the other  exertions.   In the great  majority  of
 cases, however, the  cause is  very different.   In general,
 the diet  is sufficiently varied and abundant, and the balance
 of functions sufficiently equal, to leave a considerable quan-
 tity of alimentary residue  and  effete matter to be thrown
 out by the bowels ;  and if it is not regularly expelled, some
 obstacle  of a different kind must exist, which, in the first
 place, ought to be removed, before we can expect to suc-
 ceed in restoring the natural action.   To  learn what that
 obstacle  is, let us turn  our attention for a moment  to the
 natural means  by which the intestinal evacuations are ef-
 fected.
   The progress of the intestinal contents along their canal
 depends, first, on  their  affording the necessary stimulus  to
 excite the contraction of the muscular coat;  secondly, on
 the assistance derived from the free action of the abdominal
 and respiratory muscles, not only  during  respiration, but
 during every kind of bodily exercise ; and, thirdly,  on the
 inner surface of the intestine being duly lubricated with the
 mucous secretion.   If any or all of these conditions be un-
 fulfilled,  the inevitable result will be morbid sluggishness of
 the intestinal action, and the various consequences depen-
 dant on it;  and hence,  when the evil exists, the first point
 to be determined is the  nature of the cause by which it  is
 produced.
   As already remarked, farinaceous, gelatinous, and other
 concentrated aliments do not afford the requisite stimulus
 to the muscular fibres of the intestine; because they are
 in a great measure absorbed, and leave little to be thrown
 out.  If,  therefore, concentrated food be the cause of cos-
 tiveness,  the proper remedy is to alter the diet, and to have
 recourse  to other means  only where that proves insufficient.
 If, again, the inactivity  of  the  bowels proceeds  from the
 food not being sufficiently digested, and from their contents
 being on  this account inadequate to excite them to healthy
 and regular action, it follows, as a necessary consequence,
 that, before we can expect to  obtain intestinal regularity,
digestion must  be improved by steady perseverance in a 
        DIFFERENT CAUSES OF INACTIVE BOWELS.     269

proper regimen, and such other means as may be required
to restore the tone of the stomach.   It is in cases of this
description that the practitioner is most frequently consulted.
If he and the patient are satisfied with simply procuring
relief, he has  ready means at hand in  any of the ordinary
purgatives.   But if a cure is their object, they must go back
to the root of the evil,  and begin by restoring the diges-
tive  organs to health as the first step toward permanent
success.
   The observance of a proper adaptation between the quan-
tity of the food and the  state of the  digestive organs and
mode of life is, then, not less essential to the proper action
of the bowels than to that of the stomach.   If we eat more
than the  system requires, the bowels become oppressed and
weakened  by their load ; and it is in  such  circumstances
that  purgatives afford immediate relief by the  removal of
the superfluity, and, by blinding the individual to the real
nature of the  evil, tempt him to recur too frequently to the
use of medicine.
   Where, however, as most frequently happens, the con-
stipation  arises chiefly from the  absence of all  assistance
from the abdominal and  respiratory  muscles, and in part
only from an inappropriate diet, the first step to be taken is
again to solicit the aid of the former—first, by removing all
impediments to free respiration, such as stays, waistbands,
and  belts ; and, secondly, by resorting to such active exer-
cises as shall call the muscles into full and regular action :
and  the  next is  to  proportion the quantity  of food to the
wants of the system and to the condition of the digestive
organs.  If we employ these means systematically and per-
se veringly, we shall rarely fail in at last restoring the healthy
action of the bowels with little aid from medicine.   But if
we set these natural conditions at defiance,  we may go  on
for years, adding pill to pill, and dose  to dose, without ever
attaining the end at which we aim.
   How, indeed, can it be otherwise 1  If the Creator has
so constituted us that the free play of the lungs and mus-
cles  is indispensable to proper intestinal action, it is in vain
for us to struggle against the arrangement, and  expect  to
substitute  beneficially the stimulus of purgatives  for that
of the natural play of the muscles.   Either we must give
up our own obstinate adherence to sedentary pursuits and
conform to the divine laws, or we must submit t6 the pun-
                           23* 
270      NATURAL AIDS TO INTESTINAL ACTION.
 ishment inseparable from disobedience, and merely endea-
 vour to mitigate its severity by such partial remedies as lie
 within our reach.        '
   Where bodily weakness, or any other cause, absolutely
 prevents us from engaging in active bodily exertion, cor-
 responding moderation  in  eating, and continued kneading
 and rubbing over the region of the bowels, when used daily
 and persevered in till the strength be restored, are of great
 service in promoting their healthy action.   Where great
 sluggishness of the  bowels exists, and no exercise can be
 taken, the rubbing generally  requires  to  be continued for
 an hour or more daily, or even twice a day.
   Sometimes intestinal  inaction proceeds from defective
 mucous secretion on the surface of the internal coat, caused
 either by errors in diet  or  by  local irritation.   When  cos-
 tiveness is excited in this  way, a mild diluent regimen will
 generally remove it.  It is in such cases that saline medi-
 cines, which act  by increasing the mucous secretions, are
 often very useful; while aloetic and other stimulant purga-
 tives increase the evil by aggravating the irritation.
   Such being the mode of action of the bowels, and such
 the  natural  agents by which it is carried on, we can  now
 appreciate the folly of seeking to apply  the same remedy tC
 every kind of costiveness. no matter from what cause  it pro-
 ceeds.  If a clerk who sits motionless all day in an  office,
 who indulges his  appetite, and has no bodily exercise to
 facilitate respiration and give a natural impetus to the bowels,
 begins after a time to complain of constipation, it is  not
 difficult to tell what is required for his cure.  The first step
which a knowledge of the  animal functions would suggest
is, to diminish the food to such a quantity as the  system re-
quires and the stomach can digest; the next, to use such
a diet as is calculated to excite the muscular coat of the
intestine to healthy activity ;  the third,  to seek the natural
aid arising from exercise of the abdominal arid respiratory
muscles ; and the last of all, to have recourse, when neces-
sary, to such medicines as may for a time  be required to
restore the tone of the bowels, and enable them to act with-
out farther assistance.   The course usually adopted, how-
 ever, is widely different from that here  described.   From
ignorance of the laws of organization,  the patient is not
aware of the extent to which he infringes them in his con-
duct, and, consequently, rests satisfied  with lamenting his 
REGULARITY OF BOWELS IMPORTANT.       271
hard fate in possessing such a bad constitution, and resort-
ing to strong medicines to force that action which he feels
to be essential  to health, but which he will not consent to
elicit by the means with which Nature has furnished him.
  Among the middle and higher classes  very many females
act on the same erroneous  plan, and with equally unfortu-
nate results.   In them the evil is aggravated by the tight-
ness of their  clothing impeding almost entirely the descent
of the diaphragm, and the free play of the abdominal mus-
cles, in respiration.
  From this  view of  the nature and cause of costiveness
it will be evident that, as  a general rule, the bowels  are
perfectly competent to the discharge  of their  functions,
when the conditions  essential for their healthy action are
duly fulfilled.   And hence, whenever they become morbidly
inactive, we  may rest assured that, in some point or other,
our  own management is or has  been defective;  and  the
surest  way to  remedy the evil is, not  to  have instant re-
course to medicine, but to begin by discovering and amend-
ing  the  defect.  In  the rare occurrence of  constipation
among children and other  actively employed  persons, we
have ample  proof of  the  fundamental  principle that  the
bowels do not  naturally stand in need of the  stimulus of
medicine, but require only to be properly treated to fit them
for the office with which they are charged.
   While, then, I entirely agree with public opinion in at-
taching great importance to the  proper regulation of the
bowels, and  in tracing much suffering  to their neglect, I
am only the more anxious that we should, as far as possible,
follow Nature in our arrangements, and reap the benefit of
her aid.   If we do  so, we shall not only be less frequently
obliged to have recourse to medicine, but, by our knowledge
of the causes of the deficient action, be greatly assisted in
our selection of an appropriate kind of laxative, and thus
avoid forcing the constitution too far.   It sometimes hap-
pens, for example, that, from debihty of the muscular coat,
the peristaltic motion is insufficient to propel the contents
of the intestines, even with the aid of proper diet and exer-
cise.   In such cases small  doses of  aloes  or rhubarb,
or other laxatives,  which act chiefly by exciting the mus-
cular contraction,  will be sufficient to clear the bowels,
especially when any mild  tonic  is conjoined  with them;
while saline  laxatives, which act chiefly on the mucous coat, 
272         DYSPEPSIA IN EARLY LIFE FROM
may be given freely, and  even cause  numerous watery
evacuations, and yet  the real or solid contents of the intes-
tines continue unremoved.   In practice this often happens ;
and hence the frequent mistake of  supposing that there is
proper passage from the bowels, when,  in reality, there is no
such thing.
  The period of life at which intestinal inactivity is  at-
tended with the  most serious  consequences is, at and for
a few years after puberty.  At that age a sudden change
is often made from the restless activity of youth to all the
stillness of a sedentary profession, without any correspond-
ing alteration being made in the quantity of food consumed.
The vigorous appetite, which  is perfectly natural during a
period of growth and great bodily activity, remains at first
unimpaired, and  impels the individual  to eat  an amount
of food far  beyond the present necessities of the system
or the powers of digestion.   The  consequence  is a ten-
dency, not only to fulness from excessive nutrition, but to
obstinate  digestive disorder from the stomach and intes-
tines  being weakened both by want  of exercise and  by
excess of food.   From pretty  extensive  observation, I am
confident  that a large proportion of the severe dyspeptic
cases attended with  great derangement and imperfect ac-
tion of the bowels,  which occur, in what are considered
regular living men,  on  the approach of manhood, or be-
tween twenty and forty years  of age, are fairly attributa-
ble to this cause, and might be avoided by the exercise  of
a rational foresight ;  and I have known several who suf-
fered  severely in this way for  years,  emphatically lament
the ignorance which  betrayed them into the error.  There
are many persons, no doubt, constitutionally too devoted to
intemperance to be corrected by any such considerations ;
but there are also many misled, less by  the force of  appe-
tite than by ignorance, who may profit by the remark.
  After the above observations were written, I was struck
with a remarkable confirmation of them in  the excellent
work  recently published by Mr.  Parker, of Birmingham,
" on the stomach and its morbid states."  After describ-
ing the mode in which repeated attacks of gastric irritation
ultimately induce disorganization of the stomach,  Mr. Par-
ker says,  " I have had  the' charge of several  patients  in
the latter stages of gastric diseases, who have been able
distinctly to trace the commencement of their complaints. 
         NOT ADAPTING DIET TO CIRCUMSTANCES.     273

These have seldom commenced before the age of twenty-five,
at the periods when they had began  the habitual use of a
fuller and  more stimulating  diet than  that of the earlier
periods of life.   The symptoms with which they were first
affected  were those of simple  indigestion,  in its various
forms of pain or distention after food, nausea, or vomiting.
These have ceased at intervals, have been relieved by va-
rious plans of treatment, but have shown a disposition to
recur at  longer or  shorter intervals from dietetic errors or
excesses, or  from other causes,  in more aggravated  and
obstinate forms than those in which they first made their
appearance, and accompanied by  sympathetic irritations in
the head, heart, liver, or  lungs, exhibited in the forms of
giddiness,  palpitations,  jaundice, or cough."  " Many of
the patients in whom dyspeptic symptoms have commenced
about the ages of  twenty or  thirty, have fallen victims to
gastric diseases  and their complications at the ages of from
forty-five to fifty-five."—P. 47.   Mr. Parker supports his
position by numerous cases, the histories of which are de-
tailed by the patients themselves, and, with the slight dif-
ference that  he  speaks  of the patients  beginning the use
of the full and  stimulating diet at twenty-five, when, ac-
cording to  my observation, their  error consisted rather in
continuing the  full diet of earlier life, we  entirely agree
in opinion.   The effect is, however, much aggravated when,
to mere  excess in quantity, a stimulating quality is added,
such as  arises from the indulgence in wine  or ardent spi-
rits, common enough in young men at the  age to which
Mr. Parker refers.  In such circumstances it  is not the
stomach alone which suffers.   The bowels also become
seriously disordered, lose  their natural tone, and thus seem
to demand the  constant aid of  medicine.   In one  case,
arising from pure  excess of eating after growth had finish-
ed,  four years of continued bad health  in an otherwise
sound constitution  were  the penalty inflicted before the
real eause was accidentally discovered.  During all that
time, too,  temporary relief invariably followed the use of
purgatives, and seemed in some measure  to point to the
truth ;  but fiom the mind never having  been directed to
the  principles, its practical  bearing was overlooked, and
now the individual wonders that  the cause did not, even at
first  sight, arrest the attention of his medical advisers.  :
   In cases of this description, however, it ought to be ob- 
274       REGULARITY OF BOWELS IMPORTANT.
served that it is not the mere  constipation which injures
the health and requires to be removed.  It is, in reality, to
the mode of life which induces  it that we  ought to direct
our attention; for. unless that be amended, all our efforts
to preserve the health by merely removing the effect will
prove insufficient.
   In the natural and healthy state, under a proper system
of diet, and with sufficient exercise, the bowels are relieved
regularly once every day.   In some constitutions, however,
the ordinary period is shorter or longer than this—twice a
day, or only once in two  days ; but such  differences  are
unimportant when  they do not proceed from morbid causes
or in any way disturb the health.  Habit, in this as in other
operations  under the influence of the nervous system, is
powerful in  modifying the result, and in sustaining healthy
action when once  fairly established.  Hence the  obvious
advantage of observing as much regularity in relieving the
system as in taking our meals, and the impropriety of at-
tempting to break through the habit  when once formed.
Sleep seems to be  favourable to the progress of nutrition,
and it is apparently during the night  that the assimilation
of the daily food is completed,  and its residue prepared for
being expelled along with the other  excretions.  Hence
there is a natural tendency in the bowels to act in the morn-
ing, and we  ought, therefore, to encourage  it by a voluntary
effort.   Even the  reception of  breakfast into the stomach
seems to act as a stimulus to intestinal contraction, and, in
consequence, many persons experience the inclination im-
mediately after their morning repast, and suffer if they  are
prevented from yielding to it.
   Where, either from constitutional weakness, sedentary
occupation,  or other unavoidable causes, the bowels  are
unable to act sufficiently to relieve the system without as-
sistance, we have,  of course, no choice but to select that
which is most suitable to the circumstances and most gen-
tle in  its operation ; because, if assistance be not afforded,
the health will assuredly suffer.  Numerous examples  of
this kind are met with every day ; and, when treating them,
we should always be careful to aid nature as far as  possible
by an appropriate diet and regimen, and not trust to medi-
cine alone for rectifying the consequences of the patient's
misconduct.   In the great majority of cases the action of
the bowels may  be restored with little or  no aid from me- 
CONCLUDING REMARKS.             275
dicine, provided a suitable regimen  be observed, and the
result be awaited with patience and  prudent forbearance.
I have already seen many examples of this fact in persons
who had been accustomed for years to the use of purgatives,
and believed they could not exist  without them.  It is true
that some inconvenience was experienced  at firsthand that
some  caution was required in determining how far to trust
to the efforts of Nature.  But in no instance  did any bad
consequences  result even  from considerable delay,  when
precautionary means were  used to prevent it.   In this, as
in other instances, we ought never to lose sight of the great
truth, that, if the bowels were  originally constituted by the
Creator with power to act sufficiently on the application of
their  own stimulus, food, there must necessarily be a wide
departure from His  laws in some part of our conduct to
cause the loss of that power ;  and, therefore, whenever we
find the  bowels unable to act without medicine, our first
business ought to be  to discover  and rectify the error into
which we have fallen—and recourse should be  had to medi-
cine only in so  far as it shall  be  necessary to remedy the
consequences which the transgression has brought upon us.
   As the sole object of the present volume is  to make the
reader acquainted with the natural laws of the animal eco-
nomy, and with the means by which  aberrations from them
may be prevented and health preserved, I shall not enter at
all upon  the discussion either of  the morbid conditions of
the bowels or of the remedies by which these may be cured
—and, consequently, shall say  nothing farther of the use of
purgative or other medicines.   The  consideration of these
matters is not only foreign to the subject, but would require
an extent of detail much beyond my present limits.
   Perhaps some persons may think that, before concluding,
I ought to apologize for having introduced to the notice of
the general reader such topics as those  discussed  in this
and some of the former chapters.  In doing so, I have been
actuated by a deep sense of the misery arising from the pre-
vailing ignorance on topics which, although in themselves
as interesting and important  as  any to which the human
mind can,' ie directed, have, nevertheless, been passed over
in sih nee, partly from not the least suspicion being generally
enter ain ed of their  real  bearing on our health and happi-
ness, an 1 partly also  from false notions of delicacy divert-
ing al te ntion from their calm and deliberate examination. 
276              CONCLUDING REMARKS.
In endeavouring, therefore, to unfold what I conceive to be
useful  truths, in the language of reason, I confess that I
feel no apprehension that any well-constituted  mind will
receive contamination from the perusal of what is contained
in these pages. 
277
INDEX.
  Abercrombie, Dr., quoted on intemperate eating, 18L
  Absorbents of the bowels, 137.
  Absorption most active before breakfast, 158.  Rapid absorp-
tion of liquids from the stomach, 50, 78.105, 121,159.
  Acids, in what  cases they promote digestion, 96.  Acidity
of stomach, 246.
  Ages, different, require different kinds of food, 187,214,234.
  Albumen, composition of, 221.
  Albuminous aliments, 227.
  Aliments.  See Food.
  Americans intemperate and rapid eaters, 179, 201.
  Animal food more digestible and nutritious than vegetable,
106,120, 217.  Different kinds of, 222.   Composition of, 221.
Cause of its greater digestibility, 122.  Also  more stimula-
ting, ib.  Why apparently more binding, 152.  Improper for
infants, 236.
  Anxiety impedes digestion, 205.

  Appetite, its necessity as a warning that nutriment is  re-
quired, 31.   Susceptible of being trained, 46.  Not to be relied
on when morbid, 47.  A guide to quantity, 182.   See Hunger.
Thirst.
  Arrow-root, 111, 120.
  Barras quoted on the sensibility of the stomach, S3.
  Bathing improper immediately after meals, 202.
  Beaumont  Dr., his view of the exciting cause of hunger, 36.
Quoted on mastication, 60.   His observations on the stomach
of a patient named St. Martin, quoted, 74, 78, 84, 97,101,112,
116 et sea  17"7, 181, 197.  Makes little pretension to the  ho-
nour  of discovery, 99, 126.  Summary of inferences drawn
from  his experiments, 126.  Quoted on the  quantity of food
proper to be eaten, 176,181.  On digestion, 197.
  Bile secreted by the  liver, 145. Account of it, 146.  Not
found in the stomach during health, 147.   Its presence  there
facilitates the digestion of fat and oily food, 248.
  Bilious temperament, 212.                                -
  Birds, gizzards of granivorous, 58,72.                    •)
  Blaine quoted on hunger, 38.

  Blood^irculated in the stomach increased by its action, 77,
197  Breathing necessary for  the conversion of chyle into
blood, 141.  Fulness of blood, 189. Bloodletting improper  im-
mediately after meals, 202.
                           24 
278
INDEX.
   Bloodvessels of the stomach, 76.
   Boarding-schools, time for breakfast and dinner in, 157, 160.
 Insufficient food often given there, 196.
   Bowels  described, 131.  Their different coats—the  peri-
 toneal, 132 ; muscular, 134;  and mucous, 135.  Action  of
 purgatives on the, 134,  136   Contain air, 135.  Their  sym-
 pathy with the skin, 136.  Excretion and absorption of the, ib.
 Conditions essential to  their perfect action, 142.  Their ver-
 micular or peristaltic motion, 134, 150.   Their nerves, 142.
 Why most open when vegetable food is used, 152.  Regulation
 of, 264.  Do not  naturally require the aid of laxatives, 187.
 Their  uses, 264 ; as an outlet of waste matter, 265.  Their
 action  bears a relation to the kind of food, ib.  Causes of their
 inactivity considered,268.  Natural ai3s to their action, 134,
 269.  General neglect of these, 271.  Bad health thence aris-
 ing, 272.  Their regularity important, 273.
   Bowel-complaint frequently produced by chill of the skin,
 136, 264.
   Brachet, his experiments showing that  hunger is  an affec-
 tion of the brain, 33.   Quoted'on hunger, 37.
   Brain, the seat of the sensations of hunger and thirst, 32.
 Should not be overtasked in childhood, 237.   Influence of its
 state upon  digestion, 203, 238, el seq.
   Brains as food, 228.
   Breakfast, proper time for, 157.  Labour before it improper
without refreshment, 160.   Diseases, easily  caught  before
breakfast, 158.  Reading newspapers during it improper, 59.
   Brigham, Dr., referred to, 238.
   Caldwell, Dr., quotedon intemperate eatingin America, 179,
201,206.  On the influence of the state  of the brain  as a
source of indigestion, 217.
   Carnivorous animals have small organs of digestion, 70,121,
125. Their existence necessary, 91.  Their gastric juice, 94.
   Carswell, Prof.,  on softening and erosion of the dead sto-
mach by the gastric juice,, 92, note
   Cassius,  his leanness  as described by  Shakspeare, 205.
  Cheerfulness promotes digestion, 111,217.
  Chewing, 51.   See Mastication.
  Chicken, 224.
  Children, great importance of regulating their diet properly,
165, 185.  Prevalent  error of over-feeding them. 184, 236.
Suffer  also from deficiency of food, 236.   Animal diet not to
be given them too early, 235.   Impropriety of tasking and con-
fining them too much at  school, 237.  Dull children often be-
come talented men, ib.
   Cholera, loss of the fluid parts of the body in, 50, 137.
   Chyle, 66.  Its  composition the same, from whatever food
derived, 63.  Chyliflcation described, 130.   This subject ra-
ther obscure, ib.  Chyle  converted into blood in the lungs, 140. 
INDEX.
27*
  Chyme, 65,127.
  Clark, Sir James, on the great importance of the proper re-
gulation of diet in youth, 236,242.
  Clarke, Adam, a dunce at school, 238.
  Climate ought to modify food, 124.  Appetite in warm cli-
mates, 43.
  Coagulation of milk and albumen by gastric juice, 93,104.
  Ccecum, 149.
  Coffee after dinner, 171.
  Colon described, 149.
  Condiments, 128.
i  Constitution.   See Temperament.
  Consumption, pulmonary, how productive of leanness of the
body, 141.   Often the result of mismanagement of diet  in
childhood, 237, 242.
  Cookery, influence of, 220.                       ,
  Cornaro, 181.
  Costiveness, causes of, 134, 189,267.  Howremoveable,272.
  Crime from deficiency of food, 195.
  Cumberland, Richard, beneficial effects of his temperate
habits, 230.
  Deffand, Madame de, quoted, 37.
  Deglutition of food, 61.
  Diet, adaptation of, to individuals, 231, 244.   To circum-
stances, 183.  Errors in, in maturity, 190.   Defective, of la-
bouring classes, 194.  Effects of, on crime, 195.  See  Food.
Meals.
  Dietetics, principles of, viewed  in relation to the laws  of
digestion, 153.
  Digestion, vigorous and rapid in proportion to the quantity
of nourishment required by the body, 39.  Organs of, described,
63, et seq.   Its wonderful power of reducing the most opposite
varieties of food to the same  substance, ib.  Nervous  energy
essential to, 81, 228.   Different theories of, 99.   Is a  chemico-
vital  process, 101.   Conditions  requisite for it—1. A suffi-
ciency of gastric juice, ib.  2. A temperature of 98° or 100°,
106:  and 3. Gentle agitation of the contents of the  stomach,
107.  Aided by laughter and cheerfulness, 111.  Ill performed
when previous meal remains in  stomach, 113.  Comparative
digestibility of different kinds of food, 116. Time required for
digestion of the same article different in different states of the
body, 119.   Animal food  more digestible than vegetable, 106,
120,217,219 ; and why, 121.   A proper selection of food not
the only requisite of good digestion, 154.  Is the temperature
of the stomach raised during digestion?  125.  Vegetable food
partly digested in the intestines, 150.   Vigorous in youth, 211.
Retarded by bodily or mental exertion  immediately  before or
after eating, 203, et seq.   Intellectual  vivacity diminished 
280
INDEX.
 while digestion is going on, 201.   Influence of the mind upon
 digestion, 204, et seq.
    Dinner, proper time for, 162,174.  Early dinner-hours best,
 162.  Fashionable late dinner-hours, 168.  Relaxation neces-
 sary after dinner, 169, 202.  Time for dinner ought to vary
 with circumstances, 168.  Drams at, 263.
    Drink necessary to supply the waste of the liquid portions
 of the body. 49.  Bad  effects  when withheld, ib.  Absorbed
 directly from the stomach into the system, 50,78,105,121, 158.
 Temperature of drinks considered, 252-6.  Water as a drink,
 254, 257.  Wine and other fermented liquors, 257.  Spirits
 hurtful, 258.   Sudden  changes of its  temperature hurtful to
 the teeth, 55.  See Liquid.  Thirst.
    Dunglison's Elements of Hygiene quoted and recommended,
 251,255.
    Duodenum, 65,143.
    Dyspepsia sometimes an advantage, 192.  Prevalent  in
 United States, and why, 201, 206.  Vegetables and soup often
 bad in, 245.
    Eating ought not to  be  too rapid, 59,108.   Times of, 153.
 Eating too much, a prolific source of disease, 40,179.  Con
 ditions to be observed before and after eating, 197.   See Food.
 Meals.
   Eggs, 228.
   Epiglottis, 62.
   Excrement, 130,148.
   Excretion of waste matter into the bowels, 136.
   Exercise  renders appetite  keen, 37, 38, et seq.  Prevents
 costiveness, 180, 252,271.  Improper immediately before and
 after meals, 222.
   Farinaceous food, 106,120, 229, 247.
   Fermentation and digestion different processes, 100.
   Fermented liquors, 257.
   Fever, loss of appetite during it a wise arrangement, 46, 98.
   Fibrin, composition of, 221.
   Fibrinous aliments, 222.
   Fish, 229.
   Fluids.  See Drink.  Liquid.  Thirst.
   Follicles of the stomach, 76.
   Food necessary to supply waste of the substance of living
 beings, 27.  Requisite quantity varies  according  to circum-
 stances, 28, et seq.   Warning given by  hunger when food  is
 required, 31, 32, 37, 175.  Most  necessary durin<; growth, 39,
 241; and when the  life  is active, 40, et seq.  Error of eating
 too much, 41, et seq., 175. Thirst varies in intensity according
 to the kind of food, 49.   Mastication, 51, insalivation, 58, and
 deglutition of food, 61.  Its quality modifies  the amount of
saliva secreted, 60.  The most opposite kinds of food reduced 
281
by digestion  to the  same  substance, 63.  Different  stages
through which food passes between its reception into the sto-
mach and its  assimilation, 65.   Size of the stomach  varies
according to its quality, 70.  Advantages of our want of con-
sciousness of  its presence in the stomach, 82.   Sudden and
extreme changes of diet injurious, and why, 95.   Ought not
to be rapidly swallowed, 59,109.   Thoroughly mixed with the
gastric juice  in the  stomach, 110.  Concentrated food, why
digested  with  difficulty, 111, 123, 249.  Ought not to be taken
till previous meal is digested, 113.  Comparative digestibility
of different kinds of, 116.  Animal food more digestible and
nutritious than vegetable, 106, 120, 217, 220, 248 ; and why,
122.  Farinaceous food, 106,120, 229.   Soup, 105,  111, 121,
225.  Changes of food in the bowels, 130, 217.  Injection of
food into the  bowels, 138.   Times of eating, 154.   Quantity
to be eaten, 176.  Bad effects of eating too  much, 179.  Are
mixtures of food hurtful ? 181.   Food of children—See Chil-
dren.  Food of the poor too scanty, 193 ; consequences of, 195.
Proper food of man, 197.  Variety of human food, 208.  Dif-
ferent kinds   of animal food, 222.  Different kinds of food
suitable in different climates, 124 ; for different constitutions,
209, 232  ; and at different ages, 214, 234.
   French meals, 158.  See  Meals.  Eating.
   Gall-bladder, 146.   Gall-stones, ib.
   Game, 223.                           ,    ,     .  .  , .
   Gastric juice, 65, 83.  Secreted only when there is  food in
the  stomach,  88.  Its  chemical  composition, 90  Acts only
upon dead inorganic substances, 91.  Its power of coagulating
milk and albumen, 93, 104. Its antiseptic quality, 93, 105.
Adapted in different animals to the nature of the food, 94.
Modified in the same individual according to the wants of the
system, 96.   On which of its elements does its solvent power
depend? ib.   The amount secreted  always in proportion to
the quantity of aliment required by the body, 97, 177.  Its se-
cretion retarded by disagreeable mental emotions and fever-
ishness,97,197.  Indispensable to digestion, 101.  Thoroughly
mixed with the food in the stomach, 110.   Adaptation of food
to its qualities in different individuals, 122.
   Gelatine, composition of, 121.  Nutritive power of soup
made from, 225
   Gelatinous  aliments, 224.
   Gizzard of granivoious birds, 58, 72.
   Grief  enfeebles digestion, 111,205                     .
   Growth, periods of, require.an increased supply of food in
vegetables, 30 ; and animals, 30, 39,178.   Diet during, 241.

   Head. Sir Francis, quoted on the quantities of cold water
 drunk at the brunnens of Nassau, 160 ;  and on the prejudicial
 effects of intemperate eating, 178,189.
                           24* 
282                     INDEX.
   Heidler, case quoted from, 183.
   Herbivorous animals have large organs of digestion, 70,1"1,
 125.  Their gastric juice, 74.   The  digestion of their  food
 partly effected in the intestines, 150.
   Hippocrates, his theory of digestion, 100.
   Horse, should not have diet suddenly changed, 95.   Diges-
 tion of the, 150.   Is not fed immediately before or after a jour-
 ney, 201.  May  sometimes drink a little though perspiring,
 256.
   Hufeland quoted on the beneficial  influence of laughter in
 aiding digestion, 112.
   Hunger, necessity of the sense of, as a warning that food is
 required, 31,175.   An affection of the brain, 32.  Allayed by
 narcotics, 33, 34.   Influenced  by mental emotions, 35   By
 what condition of the stomach is it excited? 36.   Felt keenly
 when the body is in need of repair, 37, et seq.   Sharpened by
 muscular exercise, 37, 38.   Its absence  during fever a wise
 arrangement, 45.   Susceptible of being trained, 46.   Error of
 confounding it with taste, ib.  Morbid cravings of hunger when
 food is not required, 47.  Instances of extraordinary voracity,
 48.  Periodicity  of, 154. Does not return till stomach has
 been for some time empty, 155.
   Hydra, stomach of the, 67.
   Ices and ice-creams hurtful after a meal, 254. Ice useful
 in warm weather when used with caution, ib.  Examples in
 Italy and Virginia, 255.
   Ileum, 148.
   Indigestion, why prevalent  among  sedentary persons, 44,
 232.  Injures the teeth, 56.  Often  beneficial in warding off
 more serious diseases, 193.  Caused by grief,  anxiety, and
 over-study, 111,205.
  Infants, food proper for, as indicated by the  state of theit
 teeth, 55.   Diet of, 185, 234.  Prevalent  errors in the treat-
 ment of, 236.   See  Children.
  Infection, why most easily caught before  breakfast,  158.
  Injection of food into the bowels, 138.
  Insalivation of food, 58.
  Intemperate eating  a prevalent cause of disease, 178.  Dr.
 Caldwell on,  179.  Evils of, 190.  Drinking, 251.
  Intestines described, 131.  Changes on animal and  vegeta-
ble food produced in, 217. See Bowels.
  Jejunum, 148.
  Jelly, 111.
  Kitchiner, Dr., quoted on digestion, 107,156.
  Lacteals, 66,137.
  La Trappe, diet of the  monks of, 156.
  Lamb, 224.
  Laughter aids digestion, 112.
  Laxatives,  134,188,249. 
                          INDEX.                     283

  Lent, rapid recovery of the sick in Catholic countries during
it, 179.
  Liquid food, 78,105, 121, 217, 233.  Too cold or hot inju-
rious, 236,239.   Different kinds in use, 232.
  Literary men, indigestion of, 168, 203.
  Liver, its function, 145.
  Londe, Dr., quoted on the digestion of vegetables, 151.   Ex-
periments on intestinal digestion, 217.
  Luncheon, 164.
  Lungs, how wasting of the body is produced by their disease,
 141.  See Consumption.
   Lymphatics, 138.
   Lymphatic temperament, 211.
   Mastioation, process of, described, 51.  Its  apparatus va-
 rious in different animals according to the nature of their food,
 58.  Bad effects when mastication is incomplete, 59.  Pur-
 pose of, 60.
   Maturity, errors of diet in, 190.
   Meals at what times and after what intervals they ought to
 be taken, 155.   Relaxation necessary after them, 169.  Prin-
 ciples on which their times and number ought to be fixed, 172.
 Conduct  proper before and after meals, 197.   Inaptitude for
 bodily and mental exertion after them, 198.   Rest and tran-
 quillity then necessary, 199.  Whether drink is proper during
 meals, 251.  French meals, 171. See Food.  Eating.
   Meconium, 188.
   Mesenteric glands, 140.
   Mesentery, 133.
   Mesocolon, 134.                          ...
   Milk, coagulated in the stomach by the gastric juice, 93,104.
 Digested  with  ease, 120.   The natural food of infants, 186,
 235
   Miller, Captain of Glasgow Police, on starvation as a cause
 of crime, 195.                .                       ..
   Milliners, an improvement in the management oi their es-
 tablishments suggested, 184.
   Mind, its  influence on appetite for food, 35.  Deteriorated
 by defective nutrition, 195.  Ought to rest during digestion,
 199, 202.  Its influence on digestion, 205, et seq.
   Mirth promotes digestion, 111, 203,205.
   Mixtures of food, whether prejudicial, 181.
   Monks of La Trappe, diet of, 157.
   Montegre's opinion of the use of saliva, 61, 92.
   Morning, exposure before  breakfast  often dangerous, 158.
  Vigour of "the system then least, ib.
    Mortality of children, 185.   Mortality greatest among the

  l'°Mothers generally ignorant  of the rational mode of treating
  children, 186. 
 284                     INDEX.

   Mucous or villous coat of the stomach, 75; and intestines,
 136, 144.
   Muscular coat of the stomach, 73;  and intestines, 134.
 Muscular exercise.  See Exercise.
   Mutilation of animals, unsatisfactory nature of experiments
 so made, 80.
   Napoleon not a bright school-boy, 238.
   Narcotics allay hunger, 33, 34.
   Nerves of the stomach, 39, 78.   Of the bowels, 142.
   Nervous energy essential to digestion, 81, 204.  Tempera-
 ment, 212.
   Newton, Sir Isaac, a dull school-boy, 237.
   Nursing of children, 18C, et seq.
   Nutrition required to repair waste of substance in living
 beings, 28.  See Food.
   GKsophagus, 61.
   Operatives  ought not to resume work  immediately after
 meals, 204.
   Opium allays hunger, 34.
   Overfeeding, evils of, 183,188.
   Oysters, 228.
   Pancreas, and pancreatic juice, 66,148.
   Parker on dyspepsia, 272.
   Paris, Dr., an opinion of his controverted, 124.
   Pastry not easily digestible, 248.
   Periodicity of appetite, 155.
   Peristaltic motion of the bowels, 134, 150,
   Peritoneum, 73, 132.
   Philip, Dr. Wilson, an opinion of his controverted, 112.
   Pneumogastric nerve, 79.
   Poor  have larger stomachs than  the rich, 70.  Their food
too scanty and innutritious, 193.  Their  minds thereby de-
teriorated, 195.
   Precocity of talent little to, be desired, 238.
   Purgatives, their mode of action, 134,137.  Not required by
nature,  188.
   Putrefaction, digestion different from, 100.
   Pylorus, 70.  Allows  only digested food to issue from the
stomach, 115.
   Quantity of food proper  to be  eaten, 176.  Errors in, ib.
Dr. Beaumont on excess in, 170-7.   Cornaro and Cheyne on.
181.
   Rapid eating improper, 59,109, 201.
   Reading during meals improper, 59.
   Rectum, 149.  Repose before and after meals,  199.  Ob-
served in animals;201.  Evils of neglecting, ib.
   Respiration, use of, 66.  Digestion aided by, 111,  141.  Ne-
cessary  for the conversion of chyle into blood, 141.
   Rice, 106,120,265 
INDEX.
285
   Roget, Dr., quoted on nutrition, 42; on varieties of food, 64.
   Rumination  of animals,  53, 58.  Stomach of  ruminants
described, 71.                            '
   Sago, 106, 120.
   Saliva, secretion and purpose of, 58.  Its amount greatest
when food spicy, 60.  Different  in quality from gastric juice,
92.
   Salt meat, how productive of thirst, 49.
   Sanguification, 66,140.
   Sanguine temperament, 212.
   Satiety, 176.
   Schools, children too much confined and tasked in, 237.
See Boarding Schools.
   Scrofula frequently the result of a penurious diet, 196,236;
also of too exciting food, 242.
   Sedentary habits, how productive of indigestion, 41;  and
costiveness, 135,150,  272.   Less food required by sedentary
than by active persons, 182.
   Sheridan a dunce at school, 238.
   Siesta, 202.
   Skin, its sympathy  with the bowels, 136,264.
   Smith, Dr. Southwood, quoted, 82, 194.
   Soldiers, private, why inferior in strength and health to  offi-
cers, 194.   Ought not to eat immediately after a march, 200.
   Soup, digestion of, 105, 111, 121.   Gelatine soups, 226.
   Spirits, their indiscriminate use  hurtful, 258.   Effects of,
on stomach, 260.
   Spittle, 58.  See Saliva.
   Spleen, 144.
   St. Martin, Alexis,  remarkable case of, 84.  Suggestion as
to farther  observations on, 88, note.   See Beaumont.
   Stays injure the action of the bowels, 134,150.
   Starvation and crime, 195.
   Stomach,  peculiar to  animals, 28.  By what state of it is
hunger excited 1 36.  Its sympathy with the rest of the body,
36. et seq.   Described, 67, et seq.   Stomach in the lowest class
of animals, ib.   In man, 69.  Various in size according to
quantity and quality of food, 70.   Stomach of ruminating  ani-
mals  described,  71.  Coats of the stomach—external,  73;
muscular, ib. ; and mucous or villous, 75.  Its muscular action,
74.  Its bloodvessels  and follicles, 76.  Its  sanguineous  cir-
culation increased during digestion, 78.   Its power of absorb-
ing fluids, 50, 78, 105, 121,  159.   Its nerves, 78.  Contracts
when each morsel is  introduced, 109.  Its motion during di-
gestion, 111.  Is  its temperature then increased? 125.  Con-
tains no bile in the healthy state,  147.  Sensibility of the, a
sign of disease, 82.   Numerous diseases unjustly laid to its
charge, 189.  Effects  of spirits on, 260.
   Supper, in what cases proper, 171. 
 286                     INDEX.

   Swallowing, process of, 61.
   Sympathetic nerve, 82.
-  Tartar on the teeth, 55.
   Tasso, his genius precocious, 238.
   Taste, error of confounding it with appetite, 46.  Its gratifi-
 cation proper, 59.
   Tea, 171,252,255.
   Teeth  described, 51,53.   Modified  in different animals to
 suit their habits of life, 53.  Milk-teeth, 54.   Changes of the
 condition of the teeth indicate  the  propriety of certain  kinds
 of diet, 55, 234.  Necessity  of keeping them clean, 55.   Im-
 paired by indigestion, 56.  Sudden changes of temperature
 hurtful to them, 57.
   Temperaments, or constitution, different kinds of, consider-
 ed in relation to food, 208.  May be greatly modified by regi-
 men, 244.
   Temperance in eating  may be carried too far,  196.   Tem-
 perance Societies, 260.
   Temperature necessary for digestion, 106. Whether that
 of the stomach is thereby increased, 125.   That of drinks con-
 sidered, 252.
   Thinking, intense, impedes digestion, 203.
   Thirst necessary as a warning when drink is required by
 the system, 31, 50,  250.   Nature of, 33, 48.   Greatest when
 body in need of liquid nourishment, 49.  Varies in intensity
 according to nature of the food, ib.  Consequences of its cra-
 ving not being gratified, ib.  See Drink.
   Thoracic duct, 66, 140.
   Time in which the digestion of an article is effected varies
with circumstances, 119, 128.  Times of eating, 153,154.
   Tobacco allays hunger. 34.
   Tooth-powders, 56.
   Training, effects of, on eating, 156, 244.
   Travelling before  breakfast frequently improper, 160.  Diet
in travelling, 175.
   Trituration, digestion not effected by, 100.
   United States, dyspepsia prevalent in, 201.
   Veal, 224.
   Vegetables, continual waste of their substance, 26.   How
repaired, 27.  Quantity of nourishment requisite for them
varies with circumstances, 29   Principle of forcing  their
growth, ib.
   Vegetable food  less  digestible than animal, 106, 120; and
why, 122.   Also less nutritious,  121.  Its  digestion effected
to some extent in the  intestines, 151.  Properties of, 230 •
acidity from, 247.  Why more laxative than animal food, 152,'
248.
   Venison, 248.
   Vermicular motion of the bowels, 134,150,271. 
INDEX.
287
  Villous or mucous coat of the stomach, 75, and bowels, 135.
  Vomiting, inverted  action of the gullet and bowels  in, 63,
134.  Vomiting of bile, 147.              ,
  Voracity, remarkable instances of, 48.
  Waste universally the attendant  of action, 25.   Food  the
means of repairing it in living beings, 27.  See Food.   Waste
matter excreted into the bowels, 136, 248.
  Water safe as a drink, 257.  Cold spring water dangerous
when person overheated, 255.
  Water-brash, 76.
  Wine, how productive of thirst, 49.  Circumstances in
which its use  is proper and improper, 258.   Preferable to
spirits, 259.
  Worms in the bowels, 137.
  Youth, appetite  keen and digestion vigorous in, 39.   Im-
portance of properly regulating the  times of eating in youth,
166, 187.  Parents blameable for errors in, 186.   Diet in youth,
238,241.   Errors in diet of the young, 242.  Supper frequent-
ly necessary, 172.   Period of transition from youth to man-
hood a critical season, 185.  Diseases of the  stomach  and
bowels why  then common, 272.   See  Children.   Infancy.
Mothers.
THE END 
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