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NATIONAL LIBRARY OF MEDICINE
       Bethesda, Maryland

             Gift of
 The New York Academy of Medicine
 
 
 
THE
PHYSIOLOGY   OF   DIGESTION
CONSIDERED WITH  RELATION TO
THE PRINCIPLES OF DIETETICS.
            By ANDREW  COMBE, M.D.,

  FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS OF EDINBURGH,
                          AND
PHYSICIAN IN ORDINARY TO THEIR MAJESTIES THE KINO AND QUKEN
                    OF  THE BELGIANS.
 ** Nor is it left arbitrary, at the will and pleasure of every man, to do ai he list; after
the dictates of a depraved humour and extravagant phoney, ti live at what rate he plea*.
eth j but every one is bound to observe the Injunctions and Law of Nature, upon the pen-
alty of forfeiting their health, strength, and liberty—the true and long enjoyment of them-
selves."                                     Mainwayrinsx.
FOURTH AMERICAN EDITION.
            BOSTON:
MARSH,  CAPEN,  & LYON.
           NEW-YORK:
      DANIEL APPLETON &. CO
                1837 
 
PREFACE.
   The present volume is essentially a continuation
of the work first published about two years ago, un-
der the title of " The Principles  of Physiology ap-
plied to the Preservation of Health and  to the Im-
provement of Physical and Mental Education ;" and
its object is  the same—namely,  to lay  before  the
public a plain and intelligible description of the struc-
ture and uses of some of the more important  organs
of the human body, and to show how information of
this kind may be usefully applied  in practical life.
   In " The Principles of Physiology," the structure
and functions of the skin, muscles, bones, lungs, and
nervous system, the  laws  or conditions of their
healthy action, and the unsuspected origin of many
of their diseases in infringements of these  laws, were
explained  in succession and at considerable length;
and the means by which their health and efficiency
might best be  secured were pointed out.   It  was
stated that, in selecting these organs as subjects for
discussion, I had been guided by the desire to notice
in preference those functions which are most influ-
ential in their operation on the general system, and
at the same time  least familiarly  known ; and that,
if the attempt to convey the requisite information in
a manner  suited to the general reader should prove
                      A 2 
IV                  PREFACE.
successful, I would afterward prepare a similar ac-
count of others, in the right understanding and man-
agement of which our interest is not less deeply in-
volved, but in regard to which much ignorance con-
tinues  nevertheless to prevail, even among the most
liberally educated classes of society.
   The numerous proofs which I received of the util-
ity of my former work, not only from  professional
and literary journals, but also from individuals pre-
viously unknown  to me,—many of them guardians
and instructers  of youth, speaking from personal ex-
perience,—together with the  rapid sale  of three edi-
tions  (the  last  consisting of 3000 copies) in two
years, soon  completely satisfied  me that I had nei-
ther been deceived as to the real  importance of phys-
iological knowledge to the general- public, nor been
altogether unsuccessful in the method of conveying
it. ' Thus  encouraged, accordingly, I cheerfully re-
sumed my labours, and began the preparation of the
treatise now submitted to the indulgent consideration
of the reader.
   The  matters discussed on the  present occasion
relate chiefly to the function of digestion and  the
principles of dietetics; and in selecting  them I have
been guided by the  same principle as before.   It
may, at first sight, be doubted whether I have  not
exceeded  proper  bounds in thus dedicating a whole
volume to the consideration of a single subject;  but
the more we consider the real  complication of the
function of digestion,—the extensive influence which
it exercises at every period of life over  the whole of
the bodily  organization,—the degree  to which its 
PREFACE.
V
morbid derangements undermine health, happiness,
and social usefulness, and especially the share which
they have in the production of scrofulous and  con-
sumptive, as well as of nervous and mental affections,
—we shall become more and more convinced of the
deep  practical  interest which  attaches to a  minute
acquaintance with the laws by which it is regulated.
In  infancy, errors in diet, and  derangement of the
digestive organs,  are admitted  to  be  the  principal
causes of the striking mortality which occurs in that
period of life.    In youth and maturity, the same in-
fluence 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 stom-
ach or bowels.    Hence, too, the interest which has
always been felt by the public in the perusal of books
on dietetics and  indigestion ; and  hence the preva-
lent custom of using purgatives as remedies for ev-
ery disorder, very often with good, but not unfie-
quently with most injurious effects.
   Numerous  and popular, however, as  writings on
dietetics have been, and excellent as are many of the
precepts which have been  handed down  by them
from the earliest ages, sanctioned  by the warm ap-
proval of every successive generation, it is singular
how very trifling their  influence has been, and  con-
tinues to be, in altering the habits of those to whom
they are addressed.   In a general way, we  all ac-
knowledge 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 
VI
PREFACE.
 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 con-
 tradiction even with our own daily experience.
   The cause of this extraordinary anomaly—and it
 is of consequence to remark it—seems to be, not so
 much the absolute want of valuable information, as
 the faulty manner  in  which the  subject is usually
 considered.  In many of our best  works, the rela-
 tion  subsisting between the human  body on  the one
 hand, and the qualities of the  alimentary substances
 on the other, as the  only solid principle on which
 their proper adaptation to each  other can be based,
 is altogether lost sight of; so that, while the atten-
 tion is carefully directed to the consideration of the
abstract qualities  of the different kinds  of aliment,
 liitle or no  regard  is  paid to  the relation in which
they  stand to the individual constitution, as modified
by age, sex, season,  and  circumstances, or to the
observance of  the  fundamental laws of digestion.
And  hence, although these conditions are not unfre-
quently 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  are
drawn, by relying on  which upon future occasions,
 we  may easily be led into still more  serious mis-
takes.
  It is, indeed, from  being left in this way without
 any guiding principle  to direct their experience, and
 test the accuracy of the precepts laid down to them 
PREFACE.
Vll
for the regulation of their conduct, that many persons
begin by being bewildered by the numerous discrep-
ances which they meet with between  facts and doc-
trine—between counsel and experience, and end by
becoming entirely skeptical on the subject of all di-
etetic rules whatever, and regarding  them  as mere
theoretical effusions, based on fancy, and undeser-
ving 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 pro-
portion  as we advance, some useful  resujt will  re-
ward 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 ben-
eficial results.  Utility, and not novelty, has been my
great object throughout;  and therefore, although in
some instances I  have perhaps regarded known facts
in a new point of view, and deduced from them prac-
tical inferences of considerable value,  I lay no claim
to any farther originality, except such as is  implied
in the adoption of what I conceive to be an improved
mode of investigation ; and if I have anywhere used
expressions  which may seem either to  do injustice to
others, or to arrogate too much credit to myself, it
has been entirely  without any such design, and, con-
sequently, I  will be prompt to acknowledge my error
and rectify the involuntary mistake.
   In  preparing the  present volume for the  press I
have derived the utmost advantage from a very valu- 
via
PREFACE.
able work by Dr. Beaumont, an American writer,
which, though scarcely at all known in this country,
contains an authentic record of some of the most cu-
rious  and instructive observations which  have  ever
been made on the  process of digestion.   That ex-
cellent and enlightened physiologist had the rare good
fortune to meet with a case where an artificial open-
ing into the stomach existed, through which he could
see every  thing that took place during the progress
of healthy digestion ; and, with the most disinterest-
ed zeal and admirable perseverance,  he  proceeded
to avail himself of the opportunity thus afforded of
advancing human  knowledge, by engaging the pa-
tient, at a heavy expense, to live with  him for sev-
eral years, and become the subject of numerous and
carefully conducted  experiments.   Of the results
thus obtained,  I have not scrupled to make the freest
and most ample use ; both because they illustrate al-
most every point of importance connected with diges-
tion, and because,  from Dr. Beaumont's work being
still inaccessible to the British reader, it is a bare act
of justice towards him, and also the best  way of ful-
filling the objects he had in view, to make its contents
known as widely as possible :  for wherever they are
known they will be acknowledged to redound to his
credit, not less as a man than as a philosopher.
   In  the course of these pages the reader will  occa-
sionally meet with repetitions, which he may, perhaps
with justice, think  unnecessary.   The only apology
I have to offer for  them is, that the intimate manner
in which the  different functions  are connected with
each other, sometimes made it impossible to explain 
PREFACE.                  IX
one without referring to the rest; and also that, my
prime objects being to render the meaning unequiv-
ocally plain, and impress the subject deeply upon the
reader's mind, I thought it better to risk  occasional
repetition of an important  truth, than to  leave it in
danger of being vaguely apprehended, or  its enunci-
ation in any degree obscure.   For these  reasons, it
is hoped that the fault—if such it is—will  be lenient-
ly  overlooked.
   Those who wish to  study more fully the subject
of dietetics, will find much useful  information in Dr.
Hodgkin's  " Lectures on the Means of  Promoting
and Preserving Health ;'' Professor  Dunglison " On
the Influence of Atmosphere and Locality, Change
of Air and  Climate, Seasons, Food, Clothing, Bath-
ing, Exercise, Sleep, Corporeal and Intellectual Pur-
suits, &c. &c. &c. on Human  Health ;" Dr. Paris
" On Diet;" and  Dr. Kilgour's " Lectures on the
Ordinary Agents of Life, is applicable to  Therapeu-
tics and Hygiene."
Brussels, April, 1836. 
 
CONTENTS.
                       PART  I.

            PHYSIOLOGY OF DIGESTION.


                   J^HAPTER I.

               ,  TRODUCTORY  REMARKS.

Waste or loss of substance always attendant on action.—In the
  vegetable and animal' kingdoms waste is greater than in the
  physical.—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 wanSer, 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 Ap-
  petite answers this purpose.—The possession of a stomach
  implies  a  sense  of  Appetite  to  regulate the  supplies  of
  food................Page 17-25

                    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
  illustrations.—Exciting causes of hunger.—Common theories
  unsatisfactory.—Hunger sympathetic of the state of the body
  as well as of the stomach.—Uses of appetite.—Relation be-
  tween waste and appetite.—Its practical importance.—Con-
  sequences 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 rule*
  for gratifying it,.............26-48 
12
CONTENTS.
                    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—Insaliva-
  tion  and its uses.—Gratification of taste in mastication.—
  Deglutition.............Page 48-62

                    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.
  —General view of digestion, chymification, chylification, san-
  guification, nutrition.—The stomach in polypes, in quadrupeds,
  and in man.—Its position, size, and complexity, in different ani-
  mals.—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 com-
  munication 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 gas-
  tric  juice the grand agent in  digestion.—Its origin and na-
  ture.—Singular case of gunshot wound making a permanent
  opening into the stomach.—Instructive experiments made by
  Dr. Beaumont.—Important results......63-106

                    CHAPTER V.

           THEORY AND LAWS  OF DIGESTION.

Different theories of Digestion.—Concoction.—Fermentation.—
  Putrefaction.—Trituration.—Chymical solution.—Conditions
  or laws  of digestion.—Influence of gastric juice.—Experi-
  ments illustrative of its solvent power.—Its mode of action on
  different kinds of  aliment—beef, milk, eggs, soups, &c.—In-
  fluence of temperature.—Heat of about 100°  essential to di-
  gestion.—Gentle and <;ontinued 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 digesti- 
CONTENTS.
13
  ble.—Farinaceous next.—Vegetables and soups least digesti-
  ble.—Organs of digestion simple in proportion to concentra-
  tion of nutriment.—Digestibility depends  on adaptation of
  food to gastric juice more than on analogy of composition.—
  Illustrations.—No increase of temperature during digestion.—
  Dr. Beaumont's summary of inferences   .  .  Page 106-143

                    CHAPTER  VI.

 CHYLIFICATION, AND THE  ORGANS CONCERNED IN  IT.

Chylification.—Not  well known.—Organs concerned in it.—
  The  intestinal  canal.—Its   general  structure.—Peritoneal
  coat.—Mesentery.—Musculai  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 tbwards the heart.—
  Nerves of mucous coat.—Action of bowels explained.—Indi.
  vidual structure of intestines.—The Duodenum—Jejunum—
  and  Ileum.— Liver and pancreas concerned in chylifica-
  tion.—Their situation and uses.—Bile, its origin and uses.—
  The pancreas.—Its juice.—The jejunum described.—The il-
  eum— Coecum—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  ....   144-172
                      PART  II.

THE PRINCIPLES  OF DIETETICS VIEWED IN RE
      LATION TO THE LAWS  OF DIGESTION.

                    CHAPTER  I.

                   TIMES OF EATING.

The selection of food only one element in sound digestion.—
  Other  conditions essential.—Times  of eating.—No stated
  hours for eating.—Five or six hours of interval between meals
  generally  sufficient.—But must vary according  to  circum
  stances.—Habit has much influence.—Proper time for break-
  fast depends on constitution, health, and mode of life.—Inter-
  val required  between breakfast and dinner—best time for
  dinner—circumstances in which  lunch is proper—late din- 
14                   CONTENTS.
  ners considered—their propriety dependant on mode of life.-—
  Tea and coffee as a third meal—useful in certain circumstan-
  ces.—Supper considered.—General rule as to meals.—Nature
  admits of variety,—illustrations—but requires the observance
  of principle in our rules........Page 173-197

                    CHAPTER II.

         ON THE PROPER QUANTITY OF  FOOD.

Quantity  to be proportioned to the wants of the system.—Appe-
  tite indicates these.—Cautions in trusting to appetite.—Gen-
  eral 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 dis-
  ease from excess in servant-girls from the country, dressma-
  kers, &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 197-224

                    CHAPTER III.

                OF  THE  KINDS OF FOOD.

What is the proper food  of man ?—Food to be adapted to consti-
  tution and circumstances.—Diet must vary with time of life.
  —Diet  in infancy.—The mother's milk  the  best.—Substi-   i
  tutes for it.—Over-feeding a prevalent error.—Causes which
  vitiate the quality of the milk.—Regimen of nurses.—Wean-
  ing.—Diet after weaning.—Too  early use of animal food hurt-
  ful.—Diet of children  in the higher classes too exciting—and
  produces scrofula.—Mild food best for children.—Incessant
  eating very injurious.—Proper diet from childhood to puberty.
  —It ought to be  full  and nourishing, but not  stimulating.—
  Often insufficient in boarding-schools.—Diet best adapted  for
  different constitutions in mature age.—Regimen powerful in
  modifying the constitution, mental as well as physical.—Far-
  ther investigation required.........225-254

                    CHAPTER IV.

    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 towards the stomach du- 
CONTENTS.
15
  ring digestion.—Hence less circulatingin other organs.—And
  consequently less aptitude for exertion in them.—Bodily rest
  and mental tranquillity essential to sound digestion.—Rest al-
  ways attended to before feeding horses.—Hence also a natural
  aversion to exertion immediately after eating.—Mischief done
  by  hurrying away to business after meals.—Severe thinking
  hurtful at that time.—Playful cheerfulness  after dinner con-
  ducive to digestion.—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.....Page 255-268

                     CHAPTER V.

                        ON DRINKS.
Thirst the best guide in  taking  simple drinks.—Thirst in-
  creased by diminution of the circulating fluids.—The desire
  for  liquids  generally an indication of  their propriety.—Much
  fluid hurtful at meals.—Most useful three orfour hours later.—
  The temperature of drinks is of consequence.—Curious fall
  of temperature in the stomach from  cold water.—Ices hurt-
  ful after dinner.—Useful  in warm weather, when digestion is
  completed, and caution used.—Cold water  more dangerous
  than ice when  the body  is overheated.—Tepid drinks safest
  and most refreshing after  perspiration.—Kinds of drink.—Wa-
  ter  safe for every  constitution.—Wine,  spirits, and  other
  fermented  liquors, too  stimulating for general use, but bene-
  ficial in certain circumstances.—Test  of their utility 269-286

                     CHAPTER VI.

      ON THE PROPER REGULATION OF THE BOWELS.

Functions of the intestines.—The action of the bowels bears a
  natural 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 in-
  testinal 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  . •.   .  .   .  287-300
Index..................301 
WOOD-CUTS.
Under-jaw,................49
Thoracic and Abdominal Viscera, -  -......     70
Stomach,   ............----   71
Stomachs of a ruminating animal,.....■  -  -     73
Villous Coat of the Stomach,.......'  -  -   78
Aperture in the stomach of Alexis St. Martin,   -  -  -     90
Abdominal Viscera,......•.....-  ■  1*7
Horizontal section of the Abdomen,.......149
Lacteals and Thoracic  Duct,..........154
Thoracic Duct,.....«-......-.  -    I56
Contents of the Abdomen after removal of the Intestines,  161
Mucous Coat of the Duodenum,    ........163
• 
PART  I.
PHYSIOLOGY  OF DIGESTION.
CHAPTER I.
              INTRODUCTORY  REMARKS.

Waste or loss of substance always attendant on action.—In the
  vegetable and animal kingdoms waste is greater than in the
  physical.—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 Ap-
  petite answers this purpose.—The possession of a stomach
  implies a sense of Appetite to regulate the supplies of food.

  Throughout every  department  of Nature waste
is the invariable result of action.   Even the minu-
test change in the relative position of inanimate ob-
jects cannot be effected without some loss of sub-
stance.   So well is this understood, that it is an im-
portant 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, how-
ever  nicely parts may be adjusted ,to  each other,
however hard and durable their materials, and how-
ever smoothly motion may go on, still, in the course
                       B2L 
18 WASTE ALWAYS ATTENDANT ON ACTION.

of time, loss of substance becomes evident, and re-
pair and renewal become indispensable to the con-
tinuance of the action.
  It is thus a recognised fact, or general law of na-
ture, that nothing can act or move without under-
going some change, however  trifling in  amount.
Not even a breath of wind can  pass along the sur-
face 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 pol-
ished  railroad, parts with some portion of its sub-
stance at every revolution, and  in process of time
is worn out and requires to be replaced.  The same
effect is forcibly, though rather ludicrously,  exem-
plified in the great toe of the bronze  statue of St.
Peter <it Rome, which-, in the course  of centuries,
has been  worn down to less  than half its original
si:;e 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, the
existence  of which, from  the imperceptibly  small
effect of  any single act, might' otherwise  be plau-
sibly denied.
  As regards dead or inanimate matter, the destruct-
ive influence of action is constantly forced upon our
attention by every thing passing around us ;  and so
much human ingenuity is  exercised  to  counteract
its effects, that no reflecting person will dispute the
universality of its operation.  But when we observe
shrubs and trees waving in the wind, and 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 examination, however, it will appear,
that waste goes on in living bodies not only without 
     LIVING BODIES REPAIR THEIR WASTE.   19

any intermission, but with a rapidity immeasurably
beyond that which occurs in inanimate 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 ex-
tent 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 operations are at a close.
The same thing holds true in the animal kingdom.
So long as  life continues, a copious exhalation from
the skin, the lungs, the bowels, and  the kidneys,
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 circula-
tion, 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;  whereas, after
life is extinguished, all the excretions cease,  and
waste is limited to that which results from ordinary
chymical 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 remod-
elled by the hand of the workman.   But living bod-
ies, whether vegetable or  animal, possess  the  dis-
tinguishing 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 
20  RELATIONS OF VEGETABLES AND ANIMALS.

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 excretion, possessed no
means of repairing the loss, his organization would
speedily decay and perish.   This very result is fre-
quently witnessed in  cases of shipwreck and other
disasters, where, owing to the impossibility of ob-
taining food,  death ensues  from the  body wasting
away till it becomes  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 convic-
tion forced upon our minds, that in every depart-
ment of nature expenditure of material is insepara-
ble from  action; and that,  in living bodies, waste
goes on so rapidly, and by so many different chan-
nels, that life could not be maintained  for any length
of time without  an express provision being made
for compensating its  occurrence.
  In surveying the respective modes of existence
of vegetables and of animals, with the  view of
ascertaining by what means this  compensation is
effected,  the first striking  difference between them
which we perceive, is  the fixity 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 influ-
ence.  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 
TO  THEIR  FOOD  CONTRASTED.      21
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
'mpulse which it cannot resist.  At all  hours and
at all seasons  it is at home, and in direct communi-
cation with the soil from which its  nourishment is
extracted. And being thus without ceasing in con-
tact with  its  food, it requires no  storehouse 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 substances,
they would be torn asunder at every movement,
and the animals themselves exposed either  to die
from  starvation, 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 upon them, a different arrangement
became indispensable for their nutrition; and the
method by which the  Creator has remedied the in-
convenience is hot less admirable than simple.  To
enable the animal to  move about and at the same
time to maintain a connexion with its food, He has
provided it with a receptacle or stomach, where it
is able to store up a supply of materials from  which
sustenance may be gradually  elaborated during a
period of several  hours, whithersoever it happens
to go in the meantime.  It thus carries.along with
it nourishment adequate to its wants; and the small
nutritive  vessels imbibe their food from the inter- .
nal 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 
22        RELATION BETWEEN WASTE
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 zoophites, which
in other respects are so nearly allied to plants.
  The sole object of nutrition being to repair waste
and  to admit of growth, Nature has  so arranged
that  within  certain limits it is ■ always most vigor-
ous when growth or waste proceeds with the great-
est rapidity.  Even in vegetables  this  relation is
distinctly observable.  In spring and summer, when
vegetative life  is most active, and Avhen leaves,
flowers,  and fruit are to be  formed, and growth
carried 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 proportion-
ally  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 in-
terruption is then attended with much  less risk.
  In  vegetables}, the quantity of nourishment taken
entirely dependf^on, and is regulated by, the circum-
stances 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 accelerated, and a more abun-
dant  supply of nourishment becomes indispensable
to their health and existence; and hence, in a dry
soil incapable of affording a copious supply of sap,
they speedily wither and die.  Exposed to cold, on 
AND NUTRITION.
23
the other hand, and shaded from the light, their vi-
tality is impaired, and the demand for nourishment
greatly diminished.  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 any thing inherent in the constitu-
tion 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 ripen-
ed fruit of the vine in the very beginning of spring.
The whole system of forcing vegetables and fruit,
now 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
application 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
adequate supply of food, otherwise its activity will
exhaust itself, and induce premature decay.  Hence
the regular  watering  which greenhouse plants re-
quire.  But  if we  have retarded its  progress and
lowered its vitality by excluding hjbt|and light, the
same copious nourishment will noT-Jnly be unne-
cessary,  but will probably do harnfby inducing re-
pletion and disease.
  In vegetables, the absorption of food is thus regu-
lated entirely by the circumstances of heat, moist-
ure, and  light, under which the plant is placed, and
by the consequent necessity which  exisjs at the
time for a larger or smaller supply of nourishment
to carry on the various processes of vegerable life. 
 24  ANALOGY OF VEGETABLES AND ANIMALS.

 According to this arrangement, nutrition is always
 most active when the greatest expenditure of mate-
 rial is taking place.  When growth is going on rap-
 idly, and the leaves  are unfolding themselves, sap
 is sucked up from the earth in great quantity; but
 when these processes are completed as summer ad-
 vances, 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 small-
 er 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 abatement,—nutrition is reduced to its low-
 est 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 requi-
 ring to  be proportioned to  demand, less strikingly
 apparent in animals.  Wherever growth is proceed-
 ing rapidly, or the animal is undergoing much exer-
 tion and expenditure  of material, an increased quan-
 tity of food is invariably required ; and, on the other
 hand, where  no   new substance  is forming, and
where, from bodily inactivity, little loss is sustain-
ed, a comparatively small supply will suffice.  But
 as animals are subjected to much more rapid and vi-
 olent transitions from activity to inactivity than ve-
getables are—and thus require to pass more immedi-
 ately from on^juid and quantity of nourishment to
 another, in <wKJ  to adapt their nutrition to the
 ever-varying demands made upon the system—they
 evidently  stand.in  rteed of some  provision to en-
 force attention when nourishment is necessary, and
 to enable them always to proportion the supply to
 the real wants of  the body.   Not being, like ve-
 getables, 4n constant  connexion with their aliment,
 they migjjt suffer from neglect if they did not pos-
 sess some contrivance to warn them in time when 
       APPETITE NECESSARY AS A GUIDE.     25

to seek and in what quantity to consume it.  But in
endowing animals with the sense of Appetite, or the
sensations of Hunger and  Thirst generally included
under it, the Creator has guarded effectually against
the inconvenience, and given to animals a guide in
every way sufficient for the purpose.
  The very possession of a stomach or receptacle,
into which food sufficient for several hours can be
introduced at one time, and which we have already
remarked 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 thoughtless-
ness, 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 sen-
sations of .hunger and thirst, but, moreover, attached
to their regulated indulgence a degree of  pleasure
which  never fails to ensure attention  to  their de-
mands, and which, in highly civilized communities,
is apt to lead to excessive gratification.   Such be-
ing the important charge committed to the  appetites
of hunger and thirst, it will be proper to submit to
the reader; before entering upon tJP consideration
of the more  complicated process ordigestion, a few
remarks on their nature  and use.
                     C 
26  THE APPETITES OF HUNGER AND THIRST.
                  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
  illustrations.—Exciting causes of hunger.—Common theories
  unsatisfactory.—Hunger sympathetic of the state of the body
  as well as of the stomach.—Uses of appetite.—Relation be-
  tween  waste and appetite.—Its practical importance.—Con-
  sequences 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.

  In the  preceding chapter  we have  endeavoured
to show, first, that nutrition is required  only because
waste,  and a deposition of new particles, are con-
tinually going on, so that the body would speedily
become exhausted if  its constituent materials were
not renewed; secondly, that the sense of appetite is
given to animals for the  express  purpose of  warn-
ing 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 vegetabLeaJiave  no corresponding  sensation,
simply  becauwHtrom their being at all times iv
communication**^ith the soil, their nutrition goes
on  continuously  in proportion as it  is  necessary,
and without requiring any prompter to put it  in ac-
tion 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 implied,  except where it is oth- 
     SEAT OF THE SENSATION OF HUNGER   27

erwise plainly expressed), the dictates of appetite
will not be every  day the same, but will vary ac-
cording to the mode of life and wants of the system,
and, when fairly consulted, will be sufficient to di-
rect 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 de-
scribe  what hunger and thirst are:  every one has
felt them, and no one could  understand them with-
out such experience, any more than sweetness or
sourness could be understood without tasting sweet
or sour  objects.   Their end'is manifestly to  pro-
claim that farther  nourishment is required for the
support of the system; and our first business is
therefore to explain their nature and seat, in so far
at least as a knowledge  of these may be 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 ail 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  Eeeling; and no
greater difficulty attends the explanation of the one
than of the others.  Thus, the caus#which excites
the sensation of  colour,  is certain rays of light
striking upon the nerve of  the eye;  and  the cause
which excites the perception of  sound,  is the at-
mospherical vibrations  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 man- 
 28     HUNGER A  MENTAL SENSATION,

 ner, 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 impres-
 sed 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 ex-
 ists, and where, consequently, indulgence'in eating
 can be  productive of nothing but  mischief.  Such
 an  aberration is  common in nervous and mental
 diseases, and not unfrequently adds greatly to their
 severity and obstinacy.  In  indolent unemployed
persons, who spend their days in meditating on their
own feelings, this craving is very common, and from
being regarded and  indulged as if it were healthy
 appetite, is  productive of many  dyspeptic  affec-
tions.*
  If the correctness of the preceding explanation
 of the  sensation of hunger be thought to stand in
need of confiroration, I would refer to the very con-
 clusive experifrents by Brachet 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,

  * Dyspepsy (from the Greek words Svs, dys, bad, and 7rsirrw,
 pepto, I concoct) is synonymous with indigestion. 
AS PROVED BY  EXPERIMENTS.      29
but the animal, which a moment before was impa-
tient 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, appa-
rently  from having no longer any consciousness 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 'gratifica-
tion 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
communication 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 such a result is
owing  to the drug being absorbed and carried to  the
brain through  the ordinary medium of the circula-
tion ;  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  moment.  The
sound  dog began immediately to feej. the effects of
the opium, and became stupid, while  the other con-
tinued lying at the fireside 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

  * Brachet, Recherches Experimentales sur les Fonctions du
Systeme Nerveux Ganglionaire, chap, hi,  Paris edition.
                     C2 
30  INFLUENCE OF EMOTION ON APPETITE.

one fell instantly into  convulsions, while the other
continued for  a long  time  as if nothing had hap-
pened.
  These results demonstrate, beyond the possibil-
ity of doubt, the necessity of a  free nervous com-
munication between the stomach and brain, for en-
abling  us to experience the sensation of hunger.
The connexion between the two organs is, indeed,
more widely recognised in practice than it is in the-
ory ; 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 to-
bacco for the same purpose.  Both substances act
exclusively on the  nervous system.
  The relation thus shown  to subsist between the
stomach and the brain, enables us, in some measure,
to understand the  influence which mental  emotion
and earnest intellectual occupation exert over the
appetite.  A man in perfect health, sitting down to
table with an  excellent appetite, 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 misfor-
tune, 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.
In such cases, no one will imagine that the calamity
destroys appetite otherwise than through the medi-
um of the brain.  Sometimes the feeling of loathing
and disgust is so intense, as not  only to destroy ap-
petite, but to induce sickness and vomiting,—a re-
sult which depends so closely on the state of the
brain, that it is often  induced even by mechanical
injuries of that organ.
  The analogy between the  external senses and the
appetite  is, in various  respects,  very close.   If we
are rapt in study, or intent  on any scheme, we be-
come insensible to impressions made on the ear or 
     CAUSE OF  THE  SENSATION OF HUNGER.  31

eye.  A clock  may  strike, or a person enter the
room, without  our  being  aware  of either  event.
The same is the case with appetite.   If the mind is
deeply engaged, the suggestions of appetite are un-
perceived and unattended to—as was well exempli-
fied in the instance of Sir Isaac Newton, who, from
seeing the bones of a chicken lying before him, fan-
cied that he had already dined, whereas, in reality,
he had eaten nothing for many hours.  Herodotus
ascribes so much efficacy to mental  occupation  in
deadening  the sense of hunger, that  he speaks of
the inhabitants of Lydia having successfully had re-
course 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.
  Many attempts  have been made  to determine
what the peculiar condition of the stomach is  which
excites  in the mind the sensation of hunger; but
little  success has hitherto attended  them.  For a
long time it was imagined that the presence of gas-
tric or stomach juice, irritating the nerves of the mu-
cous 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

  *  It is difficult, as in the above sentence, to avoid occasion-
ally using expressions, and referring td processes, which have
not previously been explained ; but it would only lead to confu-
sion and unnecessary repetition to stop at every page and intro-
duce explanations, which, after all, the reader would scarcely
understand on account  of their brevity. In the  present in-
stance, therefore, when I allude to the process of digestion, it is
better to refer the reader to the outline given at  the beginning
of Chapter IV., than to distract his attention by introducing it
also here. 
 32   HUNGER DEPENDANT ON THE STATE

 that the sensation arose partly from  the opposite
 sides rubbing against each other.  But this theory
 is equally untenable ; for the stomach generally con-
 tains a sufficient, quantity of air to prevent the actual
 contact of its sides, and moreover it maybe entirely
 void of food, and yet no appetite be felt.   It may be
 laid down, indeed, as a general rule, that an interval
 of rest must follow the termination of digestion  be-
 fore the stomach becomes fit to  resume its func-
 tions, 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
 svstem.  In many diseases, too, the  stomach  re-
 mains empty for days in  succession, without any
 corresponding excitation of hunger.   Even in heal-
 thy sedcntarv people, whose expenditure of bodily
 substance 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 exci-
ting cause of hunger, and thinks  that this view is
strengthened by the rapidity with which the juice is
poured 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 ves-
sels or follicles by which it is secreted.  But some-
thing more is required to render any of these expla-
nations  satisfactory; because  there is  an obvious
relation between appetite and the wants of the sys-
tem, which none of them take sufficiently into  ac-
count, 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 ex-
 halation from the lungs, the appetite becomes keen-
 er,  and more urgent  for immediate gratification;
 and if it .s  indulged, we eat with a relish unknown 
   OF THE GENERAL SYSTEM AND STOMACH.  33

on other occasions, and afterward experience a sen-
sation of bien-etre or internal comfort pervading the
frame, as if every individual part of the body were
imbued with a feeling of contentment and satisfac-
tion,  the very opposite of the restless  discomfort
and depression which come  upon us, and extend
over the whole system, when  appetite is disappoint-
ed.  There is, in short, an obvious and active sym-
pathy between 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 illustra-
ted during recovery  from a severe  illness.   " In
convalescence from an acute disease," as is well
remarked by Brachet, " the stomach digests vigor-
ously, and yet the individual is  always hungry.
This happens because all the wasted organs and tis-
sues 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 contin-
ual sensation  of  want, which, however,  is in this
case only sympathetic of the state of the body."*
No testimony can be stronger than this.
  The effects of exercise, also, show this connexion
very clearly.   If we merely saunter out for a  given
time every day, without being actively enough en-
gaged to quicken the circulation and induce increas-
ed exhalation from the skin and lungs, we come in
with  scarcely any change of feeling or condition;
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 lightness and energy of a very pleasurable
description, and generally accompanied by a strong

  * Brachet, Recherches Experimentales sur les Fonctions du
Systeme Nerveux Ganglionaire, p. 181. 
34    SYSTEM AND STOMACH SYMPATHIZE.

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 system and that of the stomach  is a beautiful
provision of nature, and is one of the causes of the
readv sympathy which has often been remarked as
existing between the stomach and all the other or-
gans—in other words, of  the readiness with which
thev accompany it in its departure from health, and
the'corresponding aptitude of their disorders to pro-
duce derangement of the digestive function.  Appa-
rently for the purpose, among others, of thus inti-
mately 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-inter-
woven  nervous  network  in its  immediate neigh-
bourhood, 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
condition of the nerves of the  stomach is, which,
when conveyed to the brain, expites  the sensation
of appetite, 1 think it sufficient  for every practical
purpose if we keep in mind that the co-operation of
the  nervous system is necessary 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, al-
though a comparatively short time has elapsed since
the preceding meal.
  Appetite, then, being given for the express pur-
pose of warning  us when a supply of food is neces-
sary, it follows that its call will be experienced in
the highest intensity  when waste and growth—or,
in other words, the operations which  demand sup-
plies of fresh materials—are most active ; and in
the lowest intensity when, from indolence and the 
OF WASTE AND APPETITE.
35
cessation of growth, the demand is least.  In youth,
accordingly, when bodily activity is very great, and
a liberal 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 adaptation, digestion is
proportionally vigorous and rapid: whereas, in ma-
ture age, when growth is finished, and the mode of
life more sedentary,  the  same abundance  of ali-
ment is no longer needed, the appetite becomes less
keen and more select in  its choice, and digestion
lbses something of the resistless power which*gen-
erally distinguishes it in early youth.  Articles  of
food which were  once digested with ease are now
burdensome to the stomach, and, if not altogether
rejected, are disposed of  with a  degree of labour
and difficulty that was formerly unknown.
  When, however, the mode of life in mature age
is active 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 only
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 con-
nexion between the two conditions, that exercise is
proverbially the first thing we think  of recommend-
ing to improve  the appetite and the tone of the
digestive organs,  when these are observed to be
impaired;  and where  positive disease does not
exist, no other remedy is half so effectual.
  It  is highly important to notice  this natural rela-
tion  between waste and appetite, and between ap-
petite and digestion; because,  if it be real, appetite
must be the safest guide we can follow in deter-
mining when and how much we ought to eat.   It
is true that, amid the factitious calls and wants of
civilized life, its suggestions are  often  perverted, 
36
OF WASTE AND APPETITE.
 and that hence we may err in blindly following
 every  thing 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 distin-
 guish its true dictates before we can implicitly rely
 on  its guidance.  If, when fairly consulted, its dic-
 tates are found to be erroneous, it will constitute
 the  only known instance  where  the  Creator has
 failed in the attempt to fulfil  his own design—an
 assumption not only repugnant alike to feeling and
 to reason, but in fact  altogether  gratuitous.   For
 the apparent discrepances which occasionally pre-
 sent themselves 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
 relation which nutrition ought to bear to waste and
growth.  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 re-
quires the same extensive  supply, or after a com-
plete 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  dyspeptic complaints
 often met with among the  youthful inhabitants of
our larger cities and colleges.
  The error, however, is unhappily not confined to
the young, but extends generally to all whose pur-
 suits are of a sedentary nature. There are numer-
 ous  persons, especially in  towns  and  among fe-
 males,  who, having their  time and  employments
 entirely at their own disposal, carefully avoid every 
    EVILS  OF FULL DIET AND  INACTIVITY  37

thing which requires an effort of mind or body, and
pass their lives in a state of inaction entirely incom-
patible with the healthy performance of the various
animal functions.   Having no bodily exertion to
excite  waste, promote circulation, or stimulate nu-
trition, they experience little keenness of appetite,
have weak powers of  digestion, and  require but a
limited supply of food.   If, while inactive and ex-
pending 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, they would
fare comparatively well.  But having  no imperative
occupation, and no enjoyment from active and use-
ful exertion, their time hangs heavily on their hands,
and they are apt  to haye recourse to eating  as the
only avenue to pleasure still open to them; and,
forgetful or ignorant of the relation subsisting be-
tween waste and nutrition, they endeavour to renew,
in the  present indulgence of appetite, the real en-
joyment which its legitimate gratification  afforded
under different circumstances.  Pursuing the pleas-
ures of the table with the same  ardour  as before,
they eat  and drink freely and abundantly, and, in-
stead 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 eventu-
ally aggravate the mischief by obscuring its prog-
ress and extent.   The natural result of this mode of
proceeding is, that the  stomach becomes oppressed
by excess of exertion—healthy appetite gives way,
and morbid craving takes its place—sickness, head-
ache, 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.   ISO far, however, is  the  true cause  of all 
38 EVILS OF  NEGLECTING  THE  RELATION

these phenomena from being perceived even then,
that a cure is sought, not in a better regulated diet
and regimen, but from bitters to strengthen the stom-
ach, laxatives to carry off the redundant materials
from the system, wine to overcome  the sense of
sinking, and  heavy lunches to satisfy the morbid
craving which they only silence for a little.  Some,
of course, suffer in a greater, and others in a less
degree, according 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  overcharged, 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
indolent to eat and drink less than the busy and la-
borious, is established not only by  the diminished
appetite and  impaired 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.   Compared
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 development,"  he contin-
ues, "has also great influence on the quantity of
food which an animal requires. Thus, the caterpil-
lar, which grows very quickly, and must repeatedly
throw  off its integuments  during  its continuance in
the larva state, consumes  a vast quantity of food 
       BETWEEN  WASTE  AND  APPETITE.    39

compared with the size of  its body; and hence we
find it provided with a digestive apparatus of consid-
erable size."*
  In thus insisting on regular bodily and mental ac-
tivity 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 incon-
sistency because, when treating of muscular  exer-
cise in the former volume,! I explained the bad ef-
fects, 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 pro-
moter of appetite and  digestion which we possess;
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 impos-
sible to fence round every  general proposition with
the numerous limitations which an unusual combi-
nation of circumstances, or  a departure  from the
state of health, might demand.   And, even if possi-
ble, it would not be necessary, as the laws of exer-
cise have been so fully explained in the volume al-
luded to, that  their,rediscussion here would una-
voidably 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,

  * Roget's Bridgewater Treatise  on Animal and Vegetable
Physiology, vol. ii., p. 112.
  f Principles of Physiology, &c., chapters IV. and V. 
40        DISEASE FROM INACTIVITY.
and yet loses  both  appetite and digestive power.
To render this a valid exception, it must be shown
that the European is intended by nature to live in a
tropica] climate ; because, if he is not, his condition
under such an influence  must necessarily be more
or less  closely allied to the state of disease, and
therefore beyond the sphere to  which alone my re-
marks are meant to apply.  But even in that instance
there is less contradiction than  might be supposed,
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 re-
freshing 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 struggling 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
experiment; but even  those  among them who es-
cape 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.  In others, again, the day of
reckoning is merely delayed, and there is habitually
present  a state of repletion, which clogs the bodily
functions, and  may lead to sudden  death by some
acute disease, when 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 
   DEFICIENT DIET AND EXCESS OF LABOUR.  41

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 gained  at
the expense  of a very full  habit of body, and a
liability to frequent and profuse perspirations, and
to severe  attacks of bowel complaint, endangering
life; so that even they  cannot by any means  be
regarded as real 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 digestion.   Exercise is, in fact, the condition
without which  exhalation and excretion cannot  go
on sufficiently fast to clear the  system of materials
previously taken in ; and where no waste is incur-
red, no need of a fresh supply, and consequently,
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 lux-
urious indolence and a vigorous appetite, sound  di-
gestion of 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 sub-
stance takes place than what their  deficient 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 buoyaney, early old age, and short-
er lives of the  labouring classes.  Few, indeed, of
those who are  habitually subjected to considerable
                      D2 
 42   INFLUENCE OF  DISEASE ON APPETITE.

 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 secre-
 tions are vitiated, and the stomach itself is weakened,
 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 diminution of the disease, the secretions
 and exhalations begin to return to  their  healthy
 statte, 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  for-
 mer state.   The utmost  caution, however,  is  still
 required in  its gratification, as a premature indul-
gence is almost certain again to stop the secretions
and to produce a relapse.   Ignorance of this prin-
 ciple among the community at  large, and the conse-
quent error of giving food when there is no demand
for  it, often do more to defeat  the best laid plan of
cure than the severity 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, and stealthily adminis-
ter  sustenance when the system does not require it,
and when it  serves only to aggravate the danger and
increase the weakness of the patient.
  Appetite, it ought to be observed, may, like other
 sensations, be educated or  trained to considerable
 deviations from the ordinary  standard of quantity
 and quality—and this  obviously 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 
     CONFOUNDING APPETITE WITH TASTE.  43

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.
  The most common source, however, of the errors
into which we  are apt to fall in taking appetite as
our only guide, is  unquestionably  the confounding
of appetite with taste, and continuing to eat  for the
gratification of the latter long after the former is
satisfied.  In fact,  the whole science of a skilful
cook is expended in producing this willing mistake
on our part; and  he is considered decidedly the
best  artiste whose  dishes shall recommend  them-
selves  most irresistibly to the callous palate of the
gourmand, 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 com-
munities than it is observed to be.
  Viewed, then, in  its proper light, appetite is to be
regarded as kindly implanted in our nature  for the
express end of proportioning the supply of nourish-
ment 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.   When we attend to its real dic-
tates, we eat moderately, and at such intervals of time
as the previous exercise and other circumstances
render necessary;  and  in so doing, we reap  a re-
ward in the daily enjoyment 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 
44   APPETITE  DISORDERED  BY DISEASE.

body becomes exhausted;  and in almost exact pro-
portion do the cravings of appetite  become more
and more intense, till they pass into those of uncon-
trollable hunger,  which overthrows  all  obstacles,
and seeks gratification at the  risk of  life itself.  In
the latter case, indigestion, gloomy depression, and
repletion, with  its concomitant evils, make theii
appearance, and either imbitter or cut short exist-
ence.
  Mischief sometimes arises  also from people not
being sufficiently aware, that, in common with other
sensations, appetite may be so far deranged by dis-
ease as to give very incorrect and unnatural indi-
cations.  It often happens, for example, that a pa-
tient 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 stand-
ard.   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 digested with great diffi-
culty.   Occasionally,  on the other hand, no desire
for food is experienced when the  system really
needs it, and when it would be digested with ease
if  introduced  into the stomach.  Esquirol alludes
to  cases of this description,  and  I have met with
similar  examples.   Voisin also mentions,  that, in
the Hospital of Incurables in  Paris, there are some
idiots so low in the scale of intelligence 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 nauseous and repulsive kinds of food, such as
earth, chalk, coals, and excrement.  There are states,
too, in which the appetite is prodigiously increased,
and the patient consumes incredible quantities of
food,—which, however, are very imperfectly digest-
ed   Caarles Domery, for  instance, when a French 
THIRST--ITS  SEAT.          45
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 afflicted
with a similar inordinate craving, and whose only
pleasure was in eating.   In such cases no restraint
except actual coercion is sufficient to prevent indul-
gence ; 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 removed 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 sub-
mitted  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  re-
marks.
  Thirst is generally said to  have  its seat in the
back of  the mouth and  throat; but the  condition
of these parts is merely a local accompaniment of
a want experienced by the whole frame, and per-
ceived by the nervous system.   Local applications
accordingly, go but  a short way in giving relief,
while the introduction of fluids by any other chan-
nel—by immersion  in a bath, by injection into the
veins, or through an external opening into the stom
ach—is sufficient to quench thirst without the liquid
ever touching the throat.  The affection  of that 
46   THIRST VARIES ACCORDING TO FOOD.

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
greatest  intensity when the secretion and exhala-
tion  of the animal fluids  is most  active; and it  is
consequently most urgent in summer, in warm cli-
mates, and in persons engaged in severe exertion,
particularly if exposed at the same time to a heated
atmosphere.  Blacksmiths, glassblowers, engineers,
and others, whose employment exposes them to the
heat of furnaces, and in whom perspiration is ex-
cessive, are accordingly almost  constantly under
the influence of thirst;  whereas those who are em-
ployed in professions requiring only moderate exer-
tion  in a temperate atmosphere, and in whom the
fluid secretions are very moderate, rarely  experi-
ence the sensation in an urgent degree.
  Thirst varies in intensity also according to the na-
ture 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 circumstance, is manifestly to dilute and di-
minish the excess of stimulant, and thereby prevent
the injury which  it would otherwise inflict.   The
same principle  explains the thirst experienced by
those who drink too much wine.   In instances of
this 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 ow-
ing to the wine; and yet, on abstaining from the lat-
ter, the thirst very soon disappeared.
  Continued thirst, it is well known, is much more
intolerable than continued hunger.  The  mass  of
circulating fluid in the body is very great, and,  as
the various excretions consist chiefly of fluid matter,
it necessarily happens, that when these have been
eliminated for  a  considerable  time  without any 
USES  OF  THIRST.             47
liquid being received into the system, the propor-
tion  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 cravkg of thirst
is  thus  generally rendered  more urgent and over-
powering 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 circula-
tion, and, in the second, a constant craving for drink
to  supply the  place of the lost serum, which con-
sists 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 dis-
ease, 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 per-
manent, 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  ob-
serve, are not subjected to  the slow process  of di-
gestion, but are absorbed directly into the system;
so that, when  we  take a  moderate  draught, the
whole of it is taken up 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 exhaus-
tion 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; 
48
MASTICATION.
and so long as we confine 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 come to the use of fermented and stimu-
lating liqiArs, which excite a thirst not recognised
by nature,  the principle  ceases  to operate.  At
present,  however, my observations apply entirely
to the former, and I  shall  touch upon these other
liquids when treating of diet in a subsequent part of
the volume.
                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.—Insaliva-
  tion  and its uses.—Gratification of taste in  mastication.—
  Deglutition.

  Having seen that a regular supply of nourishment
is carefully ensured by the constantly returning im-
pulses 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 endow-
ed with the properties of life.
  The first important step in the complicated pro-
cess of digestion, is thft by which the food, after be-
ing received into the mouth, is mixed with the sa-
liva, and broken down till it becomes of a uniform
pulpy consistence, fit for being easily swallowed and
acted upon by the gastric  juice on its arrival in the
stomach.  The term mastication, or chewing, is used
to denote this operation;  and the" chief instruments
by which it is performed are the teeth, the jaws, th<
muscles which move the jaws, the tongue, and th( 
DIFFERENT KINDS OF TEETH.      49
salivary glands.   On each of these we shall 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 and the higher orders of animals they may
be divided into three distinct groups: 1st, The in-
cisor, 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 subjoin-
ed wood-cut, which represents one half of  the low-
er jaw, and consequently only one  fourth of the
whole  number  of  teeth.  Thus  Ave  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.  2d,  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
                       E 
50      DIFFERENT KINDS OF TEETH.

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 intervening between  them and the cuspidati are
styled  bicuspidati, or double-speared, from bearing a
greater resemblance  to  a  double-headed canine
tooth than to the other grinders.
  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 com-
paratively undeveloped; whereas in carnivorous an-
imals, which tear their prey in pieces, the canine
teeth are large, powerful, and  pointed, and the in-
cisors comparatively small.  In these animals they
constitute what are properly called the tusks, and in
some species they are of a truly formidable char-
acter.  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 efficacy the
lower jaw admits of considerable lateral  motion in
a horizontal  direction; whereas, in carnivorous ani-
mals, it admits of motion only  upwards and  down-
wards, 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 called
—the rumination consisting in bringing up small
masses of herbage from  the stomach,  and submit-
ting them to a thorough mastication  or grinding be-
tween its molar teeth, before being again swallowed
and digested.
  From this  relation between the food  and the or-
fies the point of a spear; cants, a doe:
thing which cuts. 
VITALITY OF TEETH.           51
gans of mas.ication, naturalists  can tell  with cer-
tainty, by simply inspecting the teeth, on what kind
of food the animal to which they belong is intend-
ed to live; and as the teeth of man partake of the
characters of those of both herbivorous and carniv-
orous animals, there cannot be a doubt that his diet
was intended to be  of a mixed kind, not confined
exclusively  to either the  vegetable  or the  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, implanted in the socket of the jaw-
bone ; the neck, or portion encircled by the gum ;
and the white crown, appearing above the gum, and
covered with enamel.
  The root of each tooth is perforated longitudinal-
ly 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 afterward almost entirely
disappear.   From the nerve it derives that sensibil-
ity which makes us instantly aware of the contact
of bodies either too  hot or too cold with 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 provision 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 tooth, 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 blood-
vessels nor nerves have been observed to penetrate. 
52      DEVELOPMENT OF  THE  TEETH.
 Owing to this structure, the tooth can be safely ex-
 posed without sustaining damage—a privilege on
 which most persons will  be  disposed  to  place  a
 higher value after having experienced the pains con-
 sequent  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 them-
 selves to the growth of the jaw and the rest of the
 system at the  different periods of life.  In early in-
 fancy, 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 ap-
 pear ;  and  the whole  set of milk, deciduous, or fall-
 ing-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 ad-
 vanced so far that the first set of teeth no longer fill
 the jaw; and they soon begin  to be displaced by
J,he second, or permanent set,  the gradual develop-
 ment 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
 rudiments  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 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 
        PRESERVATION  OF  THE  TEETH.      53

nothing of this kind is to be found in the adult jaw,
the parts marked A being inserted in the plate mere-
ly 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 spe-
cies of food nature has intended for us at different
ages.   In early infancy,  when no teeth  exist,  the
mother's milk is the  only nutriment required;  and
in proportion as the teeth begin to appear, a small ad-
dition of soft farinaceous food, prepared with milk,
may be made with propriety,  and gradually increas-
ed.  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 un-
irritating materials.   It  is not  till the  permanent
teeth  have appeared  that a  full proportion of the
ordinary kinds of butcher-meat becomes either ben-
eficial  or safe.
  The teeth, being living parts, and at the same time
endowed 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-pow-
ders 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 in contact with the teeth.
   Being constantly moistened with saliva, the teeth
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 constituents in breathing, and partly
by chymical decomposition. As this incrustation not 
54      PRESERVATION OF THE TEETH.

only destroys the beauty of the teeth, but also pro-
motes their decay, it becomes an object of care to
remove i,t as soon as it is formed; and the most
effectual mode of doing so is to brush the teeth reg-
ularly twice a day—especially in the morning, when
the quantity is greatest—with a brush dipped in soft
water, till every particle is removed.  The addition
of any soft impalpable  powder  will assist in the
effect; but nothing capable of acting chymically on
the teeth, or of  injuring  them by friction,  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 digestion is impaired, the  quantity of  tartar
which accumulates 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 disor-
dered.  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 per-
fectly sound.
  When the tartar is not duly removed, its presence
injures the teeth, irritates  the gum, and generally
leads,  sooner or  later,  to considerable suffering.
The regular washing and brushing above mentioned
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 diminished,  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 in-
cessant contact injure and even  destroy the  teeth 
PRESERVATION  OF THE TEETH.      55
From this cause we often see the teeth in young
people in a state of complete decay.  They are in
reality the subjects of chymical decomposition, and
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."
  Considered as Hring parts, the teeth require some
additional care.  In that capacity they are exceed-
ingly apt to suffer from sudden changes of tempera-
ture.   Being from their solidity rapid  conductors
of heat, their internal nerve speedily becomes af-
fected by the alternations of temperature 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 fin-
ishing 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 any
thing 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 pro-
tect  the teeth  from the influence of the  sudden
change, by 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,  rheumatism  and
toothache not unfrequently  ensue  from  the direct
impression of  the  cold air  upon parts rendered
more susceptible 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 con-
tinue long unscathed. 
56           SALIVA AND ITS  USES.
  It is almost always from the latter cause that, in
infancy, teething so often gives rise to serious con-
stitutional disorder.
  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 at-
tempt to masticate it, we  encounter 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 from without.  In ordinary states of the sys-
tem, accordingly, 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 supplies directly with the process of mastication
to which  it is subservient, several  glands for its
secretion have been placed in the immediate neigh-
bourhood  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 increas-
ing 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 degluti-
tion  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 gelatin-
ous food—as the whale—no teeth are to  be found,
because their peculiar power  is not required.  In 
         MASTICATION—RUMINATION.       57

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 im-
pelled to swallow  foi 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 instru-
ment, and without its presence digestion cannot be
carried on, any more than it could in man without
the agency of teeth.
  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 animals which live
on  fresh vegetable  matter spend half their waking
hours in ruminating, or  re-masticating  the  food,
which they have already cropped and stored up for
the purpose in one of their four stomachs.  To this
necessary act in them, Providence  seems  to have
attached a high degree 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  sub-
stances, holds, as it were, an intermediate place in
regard  to the rapidity of mastication.  He neither
is obliged to ruminate like the cow, nor can benefi-
cially bolt his food with the rapidity displayed by
beasts 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 pro-
portion 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 
58       MASTICATION OF  THE  FOOD.
mass sustains  from the overflow of the salivary
secretion.
  Due mastication being thus essential to healthy
digestion, the Creator, as if to ensure its being ade-
quately performed, has kindly so arranged, that the
very act of mastication should lead  to  the gratifi-
cation of taste—the mouth being  the seat of that
sensation.   That this gratification of taste was in-
tended, becomes obvious, when we reflect that, even
in eating, nature makes it our  interest  to give at-
tention 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 indulgence of  his appetite, the
saliva begins to flow unbidden,  and what he eats is
consumed with a peculiar relish   Whereas, if food
be presented to an individual who has fasted equally
long, but whose soul is absorbed in some great un-
dertaking or deep emotion, it will  be  swallowed al-
most  without  mastication, and without sufficient
admixture with the saliva—now deficient in quantity
—and consequently lie on  the  stomach for hours
unchanged.  A certain degree of attention to  taste,
and to the pleasures of appetite, is, therefore, 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 be-
tween mastication and the salivary  secretion, the
latter  is  always most copious  in  those creatures
whose food requires continued 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 mus-
cles in the act of rumination communicates to them
a proportionate stimulus.  In those, again, which
do not masticate at all, but swallowr their food en-
tire, there is scarcely any  salivary secretion, and
the glands appropriated to it are very small.   Birds, 
USES  OF  MASTICATION.          59
and  many fishes and reptiles, belong  to the latter
class.
  From the foregoing explanation of the object and
conditions of mastication, the reason will be appa-
rent why fluids do not require to undergo that pro-
cess, and also why dry mealy substances stand in
need of protracted chewing before they can be ea-
sily swallowed.   When hot spicy food is taken into
the mouth, the secretion of saliva is immensely in-
creased,  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 unneces-
sary, and the secretion is accord;~gly  moderate.
  The chief purpose  of  mastic  ,ion,  then, is evi-
dently the minute division of *"- d aliment, so as to
admit of its being easily acted upon by the gastric
juice when received into  the  stomach.  Dr. Beau-
mont, however,  seems to me to  go too far in infer-
ring, that " if the materia alimentaria could be intro-
duced into the stomach in a finely divided state, the
operations of mastication, insalivation, and deglu-
tition, would not be  necessary."   It would  require
a more extensive range of experiments than that
which he has made, to prove that "aliment is as
well digested and assimilated, and allays the sensa-
tion of hunger as perfectly, when introducedliirectly
into the  stomach (through an opening in  the side)
in a proper state of division, as when the usual pre-
vious steps have been taken."*  It is quite true that
mastication and  deglutition are  chiefly mechanical
processes; but it is difficult to believe that so much
care would have been taken  to  provide a  proper
supply of a 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 lu-
  * Experiments and Observations on the Gastric Juice and
the Physiology of  Digestion, by William Beaumont, M. D.
Pittsburgh, 1833, p. 67. 
60
DEGLUTITION.
bricating the food.  There subsists, moreover, be-
tween the sense of taste and the power of digestion,
a certain relation, which renders it more than prob-
able that the active gratification of the former du-
ring mastication is favourable to the production and
flow of nervous energy towards the stomach, and
consequently in so far conducive to the  healthy per-
formance of digestion, that even in that point, of
view insalivation could not easily be dispensed with.
Dr. Beaumont's experiments, however, abundantly
demonstrate that  Moutegre, 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 sur-
face, and other purely chymical changes sometimes
commence  in its substance  before its digestion can
be effected. Hence often arise, especially in chil-
dren, those  pains and troubles, that nausea and acid-
ity, consequent on the continued presence of  undi-
gested aliment  in  the stomach.   By a peculiarity
of constitution, however, the stomach will not long
retain food  which it cannot dissolve.  After a num-
ber of hours,—varying, according to the state of
health, from one or two to ten, or even twenty,—it
is  either rejected by vomiting, or transmitted  un-
changed to the intestine, where its  presence irri-
tates and gives rise to colic, flatulence,  bowel-com-
plaints, and, in delicate children, not unfrequently to
convulsions.  Hence another proof  of the impor-
tance of slow and  deliberate mastication.
  As soon as the morsel has been thoroughly mas-
ticated and  impregnated with saliva, it  is ready for
transmission to the stomach.  To this part of  the
process the term  deglutition, or swallowing, is  ap-
plied.
  Immediately at the back part, of the mouth sever-
al passages present themselves, leading in different 
THE GULLET.
61
 directions—one upwards and forward into the nose,
 another downwards and in front into the windpipe,
 and a third downwards and behind into the oesopha-
 gus, or gullet, and stomach.  The last is the passage
 taken by the food, and the violent  coughing and oc-
 casional suffocation induced when  it accidentally
 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 dan-
 ger, while the rarity with which such accidents ac-
 tually happen, proves the almost unfailing efficacy of
 that, which has been devised.
  The passage of the  food into the nostrils is pre-
 vented  by the interposition of a  moveable  fleshy
 fold or valve hanging down from the palate, and vis-
 ible at the back part of the  mouth; this, in the act
 of swallowing, is stretched backwards so as  to ex-
 tend 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 yAwrns glottis, the tongue), which projects
 backwards from the root of the tongue,  and con-
 ducts the  morsel over  the glottis or opening of the
 windpipe.  The epiglottis, however, is  greatly as-
 sisted in this operation by that rising upwards and
 forwards  of  the gullet and  windpipe to meet  the
 morsel, of which we are conscious in the  act of
 swallowing, and the- effect of which  is in some de-
 gree to  hide the glottis under the backward projec-
 tion of  the root of  the tongue, and allow the mor-
 sel  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 mus-
 cular or fleshy fibres, the one longitudinal, and the
other transverse and circular, with a soft,  moist li-
ning membrane to facilitate the transmission of its
contents.   When the morsel is introduced, its upper
                      F 
62        DEGLUTITION—VOMITING.

part contracts involuntarily, and pushes the mass
downwards ; the portion now reached contracts in
its turn, and propels it farther; and so on in suc-
cession till it arrives at the stomach.
  Deglutition, or swallowing, is thus a more compli-
cated 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 per-
ceive 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,  and  that the
morsel is consequently propelled upwards into the
stomach against its own gravity.   It is well known
also,  and often made  a matter of  public  exhibi-
tion, 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 appe-
tite is keen, and the alimentary bolus or morsel is
moist and properly  softened.   It is  slow and diffi-
cult when the morsel is dry and mealy, and the ap-
petite nauseated.  In Vomiting, the  action  of  the
muscular fibres is  inverted, or proceeds from the
lower  end of the gullet towards  the  mouth;  and
hence the object is carried upwards instead of down-
wards, as in the natural order. 
SURPRISING  POWER  OF  DIGESTION.    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.
  —General view of digestion, chymification, chylification, san-
  guification, nutrition.—The stomach in polypes, in quadrupeds,
  and in man.—Its position, size, and complexity, indifferent ani-
  mals.—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 com-
  munication 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 gas-
  tric juice the grand agent in digestion.—Its origin and na-
  ture.—Singular case of gunshot wound making a permanent
  opening into the stomach.—Instructive experiments made by
  Dr. Beaumont.—Important results.

  If, in the whole animal economy, where  all is ad-
mirable, there be one operation which, on reflection,
appears more wonderful than  another,  and which
evinces in a higher degree the prodigious resources
and power of the Creator in fashioning every thing
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 be-
ings.   For,  singular as it may  appear,  recent re-
searches tend  to establish the fact,  that, even in
animals differing  so widely in their  aliment as the
herbivorous and carnivorous quadrupeds,  the ulti-
mate 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 chymical anal-
ysis.*

  *  See Roget's Bridgewater Treatise, note at p.  58, vol. ii. 
64     VARIETY  OF SOURCES  OF  FOOD.

  Remarkable, however, as this uniformity of re-
sult undoubtedly is, it becomes still  more striking
when we contemplate the variety of sources from
which food is derived for the support  of animal life.
To use the words of an able writer already quoted,
" There is no part of the organized structure of an
animal or vegetable, however dense  its texture or
acrid  its qualities, that may not, under  certain* cir-
cumstances, become the food of some species of in-
sect, 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
larger 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 silkworm
subsists almost exclusively upon the leaves of the
mulberry-tree; and many species of caterpillars are
attached each to a particular 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 poi
sonous to the generality of animals, such as euphor-
bium, henbane, and nightshade, afford a wholesome
and delicious food to others."*  Nor  are the precis-
ion and accuracy with which the same fluid—the
blood—affords to every structure of the body the
precise species  of nourishment or secretion which
its elementary composition requires, however dif-
ferent each may be  from the rest in  chymical qual-
ities, 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

      * See Roget's Bridgewater Treatise, vol. ii., p. 59. 
  ALL STRUCTURES FORMED FROM THE BLOOD. 65

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 vegeta-
ble world ; but this, instead of diminishing our won-
der, rather tends to augment  it.   The  same ele-
ments, 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
teint,  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 some-
times find the seeds and  the capsule which covers
them endowed with the most 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 bears a direct reference
to our own welfare.  We know already, that cer-
tain organs are concerned  in the processes above
mentioned, and that these organs act under the reg-
ulation of certain general laws.  If we make our-
selves acquainted with,  and  carefully fulfil these
laws, we reap a rich  reward  in the enjoyment  of
sound and vigorous digestion.   Whereas, if, either
from  ignorance or  from  carelessness, we neglect
their fulfilment, we  bring upon ourselves a severe
punishment in the form of dyspeptic or nervous dis-
ease.   Assuredly, then, alternatives like these ought 
66      GENERAL VIEW OF DIGESTION.

to excite some desire for information in the minds
even of the most indifferent.

  Before, howf ,er, 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 prop-
erties of life.  The reader will thus be better ena-
bled to understand  the meaning of various  terms
and expressions, the frequent use of which it is  al-
most 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, call-
ed the  gastric or stomach juice (from yaarnp, gaster,
stomach), by which it is  gradually converted into
a soft  grayish and  pultaceous  mass, called  chyme
(from xt,r<«5 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 contractile power of the stomach into the duode-
num (from duodenus, consisting  of twelve, because
it is supposed to  be about twelve inches long), or
first portion of the intestines.   It there meets with
the bile from the liver, and with the pancreatic juice,
which  very mu^h resembles the saliva, from the pan-
creas,  or sweet-bread (was, pas, all, and  Kpea$, kreas,
flesh, it being of a fleshy consistence), a large gland
which  lies across the spine a little below the stom-
ach, and is marked P in the wood-cut given in the
chapter on Chylification.  By  the  action of these
two fluids, the chyme is converted into two distinct
portions,—a milky  white fluid named chyle (from
X»Xos, chylos,  chyle), and  a thick yellow residue.
This process is called chylification, or chyle-making.
The chyle is then sucked  in by absorbent vessels, 
         GENERAL VIEW OF  DIGESTION.     67

extensively ramified on the inner  membrane or li-
ning of the bowels, and sometimes named, from the
white colour of their contents, lacteals, or milk-bear-
ers (from lac, milk).  These lacteals ultimately  con-
verge into one trunk, named the  thoracic duct, or
chest-pipe  (from its course lying through the thorax
or chest), and which terminates, as will be seen in a
subsequent cut, in the great vein under the clavicle,
or collar-bone, hence called subclavian vein, just be-
fore the latter reaches the right side  of the  heart;
and there the chyle is poured into the general  cur-
rent of the venous blood.
  But  although thus  mingled with the blood, the
chyle is not yet sufficiently capacitated  for its du-
ties in the system.  To complete  its preparation, it
still requires to be exposed to the  action of the air
during respiration.*  This is accordingly done by
its passing through the lungs along with the dark or
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 dis-
tributed by the heart through the arteries, to supply
nourishment and support  to every part of the body.
Hence the change which  takes place in the lungs is
properly enough named sanguification, or blood-ma-
king.
  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 nourish-
ment, 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 bulk is
increased, and  its appearance changed, by the ad-
dition of much waste  matter, which, having already
served its purposes in the system,  is at last, as  will

  ♦ For a full explanation of the nature of respiration, see the
author's Principles of Physiology, &c, chap. vii. 
68     STOMACH IN THE LOWER ANIMALS.

be afterward shown, thrown out by the same chan-
nel.

  With this general view of the nature of Digestion
before us, we can now examine more satisfactotily
the structure and mode of action of the organs con-
cerned in effecting it.  Chymificalion being the first
step in the complicated 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 organ-
ization; 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 any thing 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 trans-
parent parenchyma, full of darkish grains or points,
and offering no trace of any distinguishable 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—" a
vue d'ceil."  And what is still more strange,  when it
is turned inside out, the surface, which was  former-
ly the exterior of the body, now digests as actively
and efficiently as if it had never served any other
purpose.
  Animals of this very simple description have obvi-
ously no need of vessels of any kind, because every
part of the internal surface of the body is in imme-
diate  contact with its food, and seems to imbibe or
* Cuvier's Regne Animal, vol. iii., p. 295. 
       THE HUMAN STOMACH DESCRIBED.     69

absorb directly all the nourishment which it requires;
for vessels are wanted only where digestion goes
on in one part, and the nutriment requires to be car-
ried to  another—a  vessel being neither more nor
less than a tube for conveying the  requisite nour-
ishment from the place  in which it is prepared to
parts where its.presence is necessary.  Owing to
this extreme simplicity  of organization, a hydra
may be cut into pieces, each of which will become
a perfect animal.  But, in proportion as we ascend
in the scale of creation, the organization becomes
more  complicated, and the functions more  numer-
ous, and also more dependant 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 examina-
tion to man, and only borrow from other creatures
such illustrations as may be necessary for throw-
ing light upon the human structure.
  In man, then, the stomach is a large membranous
and muscular bag, lying under the convexity of the
lower ribs of the left side, and stretching towards
the right a little beyond the hollow commonly cal-
led the  pit of the stomach.  In shape it somewhat
resembles  the bag of a bagpipe, as will be seen
from the figure on page 71; its left or larger extrem-
ity being in contact with the  ribs, and its right or
narrow extremity  situated  under  the  pit  of the
stomach.
  Its position (Stm.) relatively to the chest,  bowels,
and liver, will be understood by inspecting the sub-
joined figure, already given in the former volume.
It is separated from the cavity of the  chest by the
diaphragm or midriff D D, with which its upper sur-
face is in  immediate contact,  and through which
the gullet  passes to enter  its left  extremity.  Its 
70              THE STOMACH,

right or pyloric extremity, marked  P in the cut on
the opposite page, lies close  to the lower surface
of the liver (Liv.), the latter being a little displaced
to show its situation.   On the lower surface it has
the appearance of resting on the intestines, 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 next figure, and  so named 
THE STOMACH.
71
from being near the «op, hear, or heart), in which
the gullet terminates, and through which food  and
drink are introduced ; P, the pylorus, or pyloric  ori-
fice (from irvXwpos, pyloros, a gate-keeper,  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 comple-
ted, and which, when the stomach is full, is nearly
on  a level with the cardia, although when empty it
is lower; SS, the smallerarch or curvature; and GGG,
the greater  arch  or curvature.  The spleen is  at-
tached to that part  of the larger arch marked with
dotted points.  From the situation of the  cardia C,
and its connexion with the gullet, it will be at once
perceived that this forms one of the points of attach-
ment by which the stomach is retained in  its place.
  In size, the stomach varies much in different indi-
viduals 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 
72     THE  STOMACH VARIES  IN SIZE.
among the rich, as the former require a larger quan-
tity of their inferior food to obtain, from it an equal
amount of nourishment.   For the  same reason, an-
imals 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 ca-
ses of diseased appetite, it has been found of enor-
mous 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 ca-
pacity and  structure of the organs  of  digestion
and the quality of the food, the  stomach and intes-
tines are  found to be very small and  short  in carniv-
orous quadrupeds  and birds of  prey, which are in-
tended to live on concentrated aliment.  The same
is the case with thegranivorous, orgrain-eatinghvc&s,
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, perhaps not  one  twentieth, and which
consequently require a large bulk of it for their sus-
tenance—the digestive apparatus is t>n a large scale,
as any one may conceive in a moment, by compa-
ring 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' conver-
sion of vegetable into animal matter;  and  accord-
ingly, 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 carnivo-
rous  animals,  the whole  intestine does not exceed
once their own length.
   In ruminating animals, such as  the sheep and ox,
 the stomach,  as  will be  seen  from  the annexed 
      STOMACH IN  RUMINATING ANIMALS.   73

figure, not only is large, to adapt it  to the bulky
nature of their  food,  but is complicated in its struc-
ture, 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 herb-
age is deposited when first swallowed, after hasty
and ineffectual mastication.  It there  undergoes a
kind of maceration, or steeping, in  a fluid provided
for the purpose; after which  it passes from the
paunch into a smaller bag, called the reticulum, or
bonnet, B, which in some animals, such as the cam-
el 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 manner for travelling through
the arid deserts where no water is  to  be obtained,
and where, without such provision, they would of
course soon perish.  So admirably is the reticulum
adapted for this special purpose, that the water con
tained in it undergoes little or no change either in
                      G 
 74   STOMACH IN  RUMINATING ANIMALS.

quality 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 chan-
ges, and is then transmitted 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 stom-
ach, the other three being merely preparatory or-
gans.
  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 crop-
ped as much herbage as fills the paunch;  and  feed-
ing is thus rendered to them a source of prolonged
enjoyment.
  In those birds, again, which live on hard grain and
seed, and possess no  organs  of mastication where-
with to bruise or grind them  down, another modifi-
cation of the digestive apparatus is found.   Nature
has furnished them with a membranous bag, called a
 crop, or craio, into which the food is received, and
where it is slightly softened by a  mucous fluid se-
 creted 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. 
      STOMACH IN  GRAIN-EATING BIRDS.    75

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 grain  as between 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, is 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 kil-
ling 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 ani-
mals 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

  * The above descriptions and figure are taken, with slight al-
terations, from the Treatise on Animal Physiology in the Libra
ry of Useful Knowledge. 
 76         COATS OF  THE STOMACH.

 ever seen an animal opened, or hanging at a butch-
 er's door.  It is a fold of the tough shining mem-
 brane, called peritoneum (from TnpiTtivu, periteino, I
 extend round), which lines the abdomen, and con-
 stitutes the outer covering of all  the abdominal or-
 gans.  Its use is obviously to strengthen the sub-
 stance of the  stomach, to  assist in binding down
 this and  the other organs in their respective situa-
 tions, and, by the smoothness and constant moisture
 of their surfaces, to enable them to move upon each
 other,  and adapt themselves freely to their different
 states of emptiness and distention.

  The second, middle, or muscular coat consists of
 fleshy  fibres,  one layer of which,  running longftudi-
 nally 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, em-
 bracing, 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 con-
 tinuation of the circular fibres of  the gullet, which
 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
afterward see,  a direct reference to the  special
function  of digestion.   By the joint  action of its
longitudinal   and  circular  fibres, the  stomach is
enabled to contract, and shorten its diameter in ev-
ery direction, so as to adapt its capacity to the vol-
ume of its contents; while, by their successive ac-
tion, or alternate contraction and  relaxation, a kind
of churning motion is produced, which contributes
greatly to 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 con-
tact of the gastric juice. 
COATS OF  THE  STOMACH.         77
  The force and rapidity of these muscular contrac-
tions  are  modified  by the  more or less stimulant
nature of the food, the state of health, exercise, and
other circumstances ;  but, according  to Dr.  Beau-
mont,  the ordinary direction  in which they take
place, and the course which they impart 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 curvature  of the stomach towards the py-
lorus, 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 under-
go  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 vol-
ume, I pointed out  (p. 95)  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 voluntary, 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 stimuli.
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
motions of  the stomach  are not intrusted to our
guidance, like those of the hand or foot.   Suppo-
sing that we were to eat three  meals a day, the di-
gestion of each requiring three  or four hours,—and
that its management depended entirely upon our su-
perintendence,—our whole attention would  be re-
quired to the process, to the exclusion of every other
duty, for ten or twelve hours a day ; and every time 
78    MUCOUS COAT OF  THE  STOMACH.

that our thoughts wandered  for  a few minutes,
digestion would stand still,  and the stomach be dis-
ordered by the chymical 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 inconvenien-
ces we are entirely freed  by the  stomach being
placed under the dominion of the involuntary nerves,
and so constituted as to perform its functions with-
out any aid from our will.

  The third and innermost  coat, called the mucous,
or villous, is  that smooth,  unequal, velvety  mem-
brane, of a reddish-white or pale pink colour, which
lines  the internal surface  of  the stomach.  From
being of  much  greater extent than the other two
coats, its surface is thrown into ruga, plica, folds,
or wrinkles, which are simple in man, but very mark-
ed in some animals,  as seen familiarly  in tripe.
The subjoined wood-cut, from the Library of Useful
Knowledge, will give some notion of their appear-
ance.  Near  the pyloric orifice the villous coat  is
doubled on itself, so as to form a  ring, called the
valve of the  pylorus, the object of  which is to pre-
vent the too early  exit of the food;   this object,
however, it  accomplishes, not  by  any contractile
power of its own, but by the aid of  a layer of mus-
cular fibres lying behind it.  The villous coat is con- 
       BLOODVESSELS OF THE STOMACH.     79

stantly covered with a very thin, transparent, viscid
mucus, and its folds are always best seen in those
who die suddenly.  After disease, when the  stom-
ach is relaxed, they frequently disappear.
  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
pinheads, 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 secreted by these follicles
be the gastric juice,  or merely the mucus already
referred to as lubricating the internal surface of the
stomach.  The latter, however, is the opinion gen-
erally entertained, and the one which is  supported,
as we shall  afterward  see, by the strongest evi-
dence ; the gastric juice being, in fact, secreted di-
rectly from the capillary or  hair-sized  vessels in
which the minute branches of the arteries terminate.
  Of the nerves and bloodvessels supplying the stom-
ach it is unnecessary to say much.  We shall af-
terward have occasion to notice the former at some
length, and to the general reader the origin and dis-
tribution of the bloodvessels are as unimportant as
they would be difficult  of comprehension; for the
nature of the red blood is the same by whatever ar-
tery 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 stomach
receives a large  supply of blood by means  of nu-
merous bloodvessels,  the principal of  which,  as
represented on the wood-cut at page  71, follow the
course of the greater and smaller curvatures  GG
and SS, and send off innumerable 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
splenic, or spleen artery, are  ramified on the  larger
curvature. 
80     BLOODVESSELS OF  THE  STOMACH.

  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 secre-
tion, 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 immedi-
ate contact of irritating bodies.   When the follicles
are diseased, as in what is called water-brash, they
sometimes  throw out a  large quantity 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 treat-
ing of the laws of exercise 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 towards it  to support  its increased action.
When it is inactive and the mind indolent, a dimin-
ished flow of blood  occurs.  In like  manner, when
the muscles are balled into vigorous action, the cir-
culation  of the blood through them is quickened,
and  their nerves  are more than usually excited:
greater waste of material is caused by the increase
of activity, and more blood, consequently, is requi-
red 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
* Principles of Physiology, &c. 
BLOODVESSELS OF  THE  STOMACH.    81
 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 corresponding 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 dis-
 tended, as to impart to  it a deeper red colour than
 it has when the stomach is empty.  The increased
 afflux of red or arterial blood to the stomach during
 digestion,  is not merely inferred  from the analogy
 of other organs. Many opportunities have occurred
 of ascertaining the fact; and, as I shall have occa-
 sion to mention, Dr.  Beaumont  very often saw  it
 take place.
  A corresponding change occurs in the veins of the
 stomach during digestion.   Their diameter becomes
 enlarged, their course more straight, and the  cur-
 rent of blood  through  them more rapid.   As the
 minute or  capillary 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 sometimes  takes place is  almost incred-
 ible ; for a large draught  of water may be thus taken
 up in  a few minutes.  Fluids mixed with camphire
or other strong-scented  substance have been given
to animals as an experiment, and, on killing them
shortly afterward, the  peculiar smell  has been de- 
 82       NERVES  OF THE  STOMACH.

 tected in the blood.   Liquids are thus not digested,
 but simply absorbed.
   Rapid, however, as the process is, poisons which
 enter the system by absorption do not by any means
 act so instantaneously 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 pre-
 vails.  We may, however, gather some useful no-
 tions by adverting to the  different sources whence
 they are derived, and comparing these with the pur-
 poses for which we know from analogy that differ-
 ent 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 perform-
 ance.  These are, first, the  pleasurable conscious-
 ness attendant on the presence of wholesome food
 in a healthy stomach, and which becomes painful
 and disagreeable when the stomach is  diseased or
the food of improper quality ;  secondly, the peristal-
tic or muscular motion which commences the mo-
 ment food is swallowed, and continues till digestion
is completed;  and,  lastly, the  different processes
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 modifications of the
 same  thing, I shall not insist on considering them
as different. 
     USES OF THE PNEUMOGASTRIC  NERVE.   83

  Although we cannot state positively what particu-
lar 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 pneumogastric* 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,
suflices 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 sub-
stances be swallowed, the action  of the muscular
coat becomes so violent as to excite sympathetical-
ly 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 dependant 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 produced when the pneumo-
gastric nerve was irritated either by the scalpel or
by the contact of alcohol.  Brachet,  also, who ex-
amined the subject with great care, obtained similar
results;  and the only plausible argument against
their conclusiveness consists  in the  double  func-
tion 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 mo-
tion to its muscular fibres.  Brachet, however, turns
this charge into an additional proof; for, on careful
dissection, it appears that the pneumogastric nerve
  * From itvtvutitv, pneumon, a lung, and yaarnp, gaster, the stom-
ach, or lung and stomach nerve- 
 84   USES OF 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 separa-
 ted so as to interrupt the flow of nervous energy to-
 wards that organ, digestion is either entirely arrest-
 ed or greatly  impaired.   By the greater number of
 physiologists  this result is considered to arise from
 the consequent stoppage of that gentle and  contin-
 ued 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 expla-
 nation is regarded as incorrect.  Magendie and Dr.
 Holland, for example, say that they have' sometimes
 observed digestion  continue even after the division
. of the nerve; and  that, when it is retarded or im-
 paired, the result arises only from the troubled state
 of respiration which the  cutting of the nerve in-
 duces  at the  same time.   To this, again, it is an-
 swered, 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 por-
 tion 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 ap-
 pears  that  little interruption of  its action takes
 place.
  Here, however, I cannot help observing, that, in
 drawing  conclusions from experiments of this na-
 ture, the constitutional disturbance inseparable from
 the infliction of extensive wounds on living animals
 is seldom taken sufficiently into account.  As regards
 digestion, for  example, it is not to be expectecf that
 that function can be carried on with all the regular- 
     USES OF THE  PNEUMOGASTRIC  NERVE.   85

ity 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 effect-
ually  by making an incision on the  side or thigh
(provided it  be sufficiently deep and painful to ex-
cite constitutional disturbance), as by  cutting the
pneumogastric nerve itself.  This being the case,
we must not be  too hasty in considering every ap-
parent result as inseparably and exclusively connect-
ed with the individual injury under our notice at the
time ; we must repeat our observations under every
variety of circumstances, and be careful to separate
the  accidental from the essential, before admitting
the  inference to be correct.  It is, in fact, this un-
avoidable source of vagueness which  so often ren-
ders experiments on living animals as inconclusive
as they are inherently cruel.
  But  after making every allowance on this ac-
count, the experiments on digestion have been so fre-
quently repeated, and so extensively varied, that the
general results already noticed may safely be regard-
ed as  demonstrated.  On all hands, accordingly, the
necessity of the  co-operation of the nervous  energy
in effecting it is  admitted ;  for no one seriously de-
nies the fact, that retardation or total cessation of
digestion ensues, when the flow of the nervous fluid
towards the  stomach is prevented by the division
and separation 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 ascer-
tained, although the fact of its necessary co-opera-
tion is rarely disputed.   As, however, the direction
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 inter-
ruption of the nervous influence consequent on its
division, we may reasonably infer that, in the heal- 
 86    USES OF THE SYMPATHETIC NERVE-

 thy state, the nerve merely transmits to the stomach
 a stimulus or  energy generated  for  the purpose
 either in the brain or in the spinal marrow and gan-
 glia—that the nerve, in short, acts only as a con-
 ductor, 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 con-
 tinued 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  advanced almost in exact proportion to the
 degree of admixture which had been effected of the
 food with the gastric juice,—an admixture now as-
 certained 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 called its vital functions—those by which
 its life is sustained—viz.,  circulation, nutrition, se-
 cretion, and absorption, are generally considered to
 be carried on under the influence of the great sym-
pathetic or ganglionic nerve, so called from its very
 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 voluntary motion.  In man, however,
 the sympathetic  nerve receives filaments from the
 sentient or feeling part of the spinal marrow, proba-
 bly 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 to the cir- 
      IMPORTANCE  OF NERVOUS AGENCY.   87

cumstance that it is through the medium of the ner-
vous communications above hinted at, that the very
remarkable influence which all must have  experi-
enced and  observed as constantly exerted by the
mind and stomach on each other, is kept up—an in-
fluence so powerful in its effects on both bodily and
mental health, as to require special notice when we
shall treat of the practical application of the present
exposition.
  The importance of the nervous agency in effect-
ing digestion  has been  denied, because we are not
conscious of the presence of  food in the stomach.
But in health the want of such consciousness is a
privilege and not a defect; and it has been admira-
bly 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 which the
stomach contained, and of the changes occurring in
each, our attention  would be so  disagreeably and
unprofitably taken up that we would pray to be de-
livered  from  the annoyance.  Where,  however,
from disease or the food being inappropriate, the
stomach is injured by what is eaten,  consciousness
then becomes painful,  for the express  purpose of
warning us that mischief has been done, and that we
must take means for its removal.
   The nerves of the stomach, it ought  to be re-
marked, have a direct  relation to undigested food;
or, in other words, undigested food forms their nat-
ural and appropriate stimulus.  In consequence of
this arrangement, when any body incapable of di-
gestion is introduced into its cavity, distinct uneasi-
ness is speedily excited, and an effort is soon made
to expel it  either upwards by the mouth or down-
* Philosophy of Health, vol. i., p. 80 
88
THE GASTRIC JUICE.
wards 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
any thing escapes into them from the stomach in an
undigested  state, it becomes  to  them a source of
irritative excitement; and hence the colicky pains
and bowel-complaints which  so  commonly attend
the passage of such undigestible substances as fat,
husks of fruits, berries, and cherry-stones, through
the intestinal canal.

  Such, then, are the component  parts of the stom-
ach,  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 gastric, 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 proper-
ties 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.   Consid-
ering the peculiar difficulties by which the inquiry is
surrounded, it  is offering no trifling homage to that
distinguished observer to say, that by means of nu-
merous, varied, 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 gen-
eral accuracy  and importance of which are  now
appreciated more and more highly, in proportion as
our knowledge advances, and opportunities  pre- 
THE GASTRIC JUICE.            89
sent themselves of bringing them to the test of ex-
perience.
  It is rarely, indeed, that we can actually see what
is going on in a healthy stomach ; but in a few in-
stances this advantage has been enjoyed, and turned
to -account in investigating the phenomena of diges-
tion.  By far the most  instructive example of this
kind which has ever occurred, has lately come un-
der the  observation of Dr. Beaumont of the Ameri-
can army ;  and, as that gentleman eagerly embraced
the opportunity  so unexpectedly afforded him, of
testing the prevailing doctrines by a series of exper-
iments,  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 far-
ther 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  Michilimacki-
nac, in the Michigan territory, in 1822, in the  milita-
ry service of the United States, was called upon to
take charge of Alexis St.  Martin, a  young Cana-
dian 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.  Beaffmont,  " consisting
of powder  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; liter-
ally  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  stom-
ach."
                       H2
#» 
90           SINGULAR CASE OF      *
  On the fifth day, sloughing took place ; lacerated
portions of the lung and  stomach  separated, and
left a perforation  into the  latter " large enough to
admit the whole length of the middle finger into its
cavity;  and also  a passage into the chest halfLas
large as his fist."  Violent  fever and farther slosh-
ing ensued ;  and for  seventeen  days every  thing
swallowed passed out through the wound, and the
patient was kept alive chiefly by nourishing injec-
tions.  By-and-by the fever subsided, the wound
improved in appearance, and after the fourth week
the appetite became good, digestion  regular, the
evacuations natural, and the health of the system
«tjpmplete.  The orifice, however, never closed ; and at
every dressing the contents of the stomachMowed
out, and its coats frequently became everted or pro-
truded so far as to equal in size a hen's egg, but they
were always easily returned.  The above figure 
WOUND IN  THE  STOMACH.        91
exhibits the appearance of the wound after it was
healed.   The  circumference of the wound EEEL,
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 BC.
  Some months after, St. Martin suffered extreme-
ly 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 unre-
mitting care with which he was treated by Dr. Beau-
mont, he ultimately  recovered, and in April, 1823,
was  going  about, doing light work,  and  rapidly re-
gaining strength.
  On 6th June, 1823, a year from the date of'the ac
cident, the injured parts  were all sound  except the
perforation into the  stomach, which was now two
and  a half inches  in  circumference.  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 vil-
lous coat began to appear, which gradually increas-
ed till it filled the aperture, and acted as a valve, so
as completely 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 ex-
perimenting on the subject of digestion,  and for ob-
serving the healthy  and undisturbed operations  of
nature free from the  agony of vivisections, and from
the sources of fallacy  inseparable from operating
on  animals.   Dr.  Beaumont  was sensible of  its
value, and accordingly pursued his inquiries with a
zeal, perseverance,  and  disinterestedness  highly
creditable to his character both  as a man and as a
philosopher.   Having been fortunate enough to ob-
tain a copy of his work, I shall not hesitate to make
free use of its contents.
  Dr. Beaumont began  his experiments  in May, 
f 92
SINGULAR  CASE  OF
   1825, and continued them for four or five months,
   St. Martin being  then in high health.  In the au-
   tumn, St. Martin returned to Canada, married, had
   a family, worked hard, engaged as a voyageur with
 .  the Hudson's Bay Fur Company, remained 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 ac-
   cordingly in August, 1829, and remained till March,
   1831.  Jle then went a second time to Canada, but
   returned to Dr. Beaumont in November, 1832, when
   the experiments were once more resumed, and con-
   tinued 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. Mar
   tin's stomach as being situated about three inches to
j  the left of the cardia, near the left superior termina-
   tion of the great curvature.   When  the  stomach
   was nearly empty, he was able to examine its cavi-
   ty to the depth of five or six inches by artificial dis-
   tention.   When it was entirely empty, the stomach
   was always contracted on itself, and the valve gen-
   erally 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 integu-
   ments five or six inches in circumference, fairly ex-
   hibiting the natural ruga, villous membrane, and
   mucous coat, lining  the gastric cavity.   This ap-
   pearance is almost invariably exhibited in the morn-
   ing before rising  from  bed."   Such was the  very
   favourable subject on whom Dr. Beaumont's obser-
   vations and experiments were m%le, and such were
   the numerous opportunities which he enjoyed for
   repeating4,hem, and verifying their accuracy.  Hav- 
WOUND IN  THE STOMACH.        93
ing given this outline, we now return to the consid-
eration of the gastric juice, on the origin and quali-
ties of which it throws much light.
  In treating of the properties of the  gastric juice,
I shall on all disputed points  give a decided prefer-
ence  to  the  observations of Dr. Beaumont  over
those of any other physiologist; 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 suggest, and for  their subsequent
repetition under  such modifications 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
judgment with which he carried on his investiga-
tions, and  the scrupulous care with which  he an-
nounces 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 he
describes to have taken place in the stomach during
healthy  digestion,  his-evidence  conies  before us
with the strongest possible claims on our attention.
   The first disputed point which is  conclusively 
94    PECULIARITIES OF  GASTRIC JUICE.

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 placing 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 stomach, Dr. Beaumont found its only contents
to consist of a little viscid and occasionally slightly
acidulated mucus mixed  with saliva, and in no in-
stance  did he  perceive  any accumulation of the
proper gastric juice.  The same results had indeed
been obtained by Tiedemann and other physiolo-
gists before the publication of Dr. Beaumont's me-
moir ; 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 en-
deavoured to discover at what time the gastric juice
begins to be poured out, and under what conditions
its secretion is carried on; and here again ocular
inspection afforded him satisfactory results.
  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 con-
siderable 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 cir-
cumstances, Dr. Beaumont  could  easily observe
what changes occurred, both when food was  swal-
lowed 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 aliment
was brought into contact with it.  The action of
the neighbouring bloodvessels was instantly in-
creased, and their  branches dilated so as to admit 
     MODES OF  OBTAINING GASTRIC JUICE.   95

the red blood much more freely than before.  The
colour of the membrane consequently 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 ner-
vous and vascular papillae could be seen arising from
the villous coat,  from which distilled a pure, colour-
less, and slightly viscid fluid,  which  collected in
drops on the very points of the papillae, and trickled
down the  sides  of the stomach till it mingled with
the food.   This  afterward  proved to  be the secre-
tion peculiar to  that organ, or, in other words, the
true gastric juice ; the mucous 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 thermom-
eter, or other indigestible body, invariably gave rise
to the exudation of the gastric fluid from these vas-
cular papillae ; but that, in the latter cases, the secre-
tion always ceased  in a short time, as soon appa-
rently as 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 procured under any other circum-
stances.
   Various methods have been employed for procu-
ring the gastric  fluid in a state of purity.  Pieces of
dry sponge, enclosed in a dry, hollow, perforated ball,
with a string  attached to it, have been swallowed
both by man and by inferior animals, and afterward
withdrawn to have the juice expressed from them.
 In some instances the stomachs of criminals  and
 animals killed after  fasting have been opened,  and
 the secretion collected.  At other times  the juice
 has been procured by voluntary or artificial vomit- 
96       ELEMENTS OF GASTRIC JUICE.
mg.  None of these methods is  equal to that em-
ployed 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 conse-
quence  of a stimulus applied after  the stomach is
opened, must necessarily be very small, and rendered
impure by the large admixture of mucus  which it
will contain; while, by the third method,  either no
gastric juice but merely mucus will  be  procured, or
it will be  expelled mixed with the food 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. Beaumont to be a clear transpa-
rent fluid, without smell, slightly  saltish (probably
from the admixture  of mucus), and very perceptibly
acid.  Its taste, he says, resembles that of thin mu-
cilaginous water, slightly acidulated with muriatic
acid.  It is readily diffusible in water, wine, or spir-
its,  and  effervesces  slightly   with alkalis—a  direct
proof, of its acid  nature.  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 Profes-
sor 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 soluble in cold, but  insoluble in
hot water.  Tiedemann and Gmelin, again, describe
it  as composed principally  of muriatic and  acetic
acids, mucus, saliva, osmazome, muriate  and sulphate
of soda, with little  or no albumen;  and,  according to
the same physiologists,  the  proportion of acid is
always greatest when vegetables or other substa>i<*»» 
     GASTRIC  JUICE A  SOLVENT  OF FOOD.   97

of difficult digestion constitute the chief part of the
diet.  Other chymists  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, but also
the necessarily different 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 every thing in the shape of
food which is submitted to its action,—while it ex-
erts 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 inorganic 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 vege-
table nature.  To a great extent, 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 ma-
chines 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 pangs of hunger, such instances form no excep-
tion to the general rule.
   It would  have been easy for the Creator to be-
stow 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 
98        ACTION OF  GASTRIC JUICE.
the source of an infinitely greater amount of active
enjoyment than 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 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 gen-
eral 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 provision, since otherwise it would at
once have attacked and destroyed the very organ
which produces it.  This is the reason why worms
are able to exist in the stomach of man and other
animals;  so that, if it were  possible  for an  oyster
swallowed directly from the shell to continue to
live, it would effectually resist every  attempt at di-
gestion.  But it, in common with most other beings,
cannot sustain life under such circumstances; and
as soon  as it dies, the gastric juice  assumes the
mastery,  and speedily converts it into  chyme.
  If any  thing could  have opened Montegre's eyes
to the fallacy under which he laboured in consider-
ing 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 
ON  THE  STOMACH.
99
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 ulcer-
ation.  It was  long before the reason of this was
discovered ; but at length it was ascertained to arise
from  the action of gastric juice (the abundant secre-
tion of which was provoked by the immediately pre-
ceding 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.   If, therefore,
the gastric juice  be merely saliva  and mucus, we
might expect to find after death some traces of sim-
ilar results from the contact of saliva with the mouth
or gullet; but there no such erosion is ever witnes-
sed, 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 gastric  juice,—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 stom-
ach before  coagulation  takes place; a fact which
leads many inexperienced mothers to infer that the
infant is already suffering from acidity, and to coun-
teract the supposed evil by repeated doses of mag-
nesia—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 separation 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. 
 100   GASTRIC  JUICE ANTISEPTIC, AND

  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 considerable way  towards putre-
 faction.  Dr. Beaumont mentions that the pure juice
 will keep unchanged for almost any  length of time;
 and, according to Spallanzani, meat may be preserv-
 ed in it without taint for five or six  weeks, or even
 longer.  This antiseptic tendency of  the gastric fluid
 accounts for the circumstance that little  or no mis-
 chief results from the common practice among epi-
 cures, of not making use of game till the putrefac-
 tive  process is advanced farther than is agreeable
 to the palates of the uninitiated.
  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 creatures, possess the power  of digesting all
 sorts of aliment, whether vegetable or animal, and
 are hence called omnivorous; 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 in-
 evitable consequence, because then the gastric juice
has not had  time to acquire its requisite adaptation
 to the new materials on  which it has to act.
  Even in its chymical constitution, the gastric juice
 of carnivorous animals differs from that of the her-
 bivorous; a circumstance which accounts for  the
  *  Macgillivray's Description of the Rapacious Birds of Great
 Britain, p. 24 
VARIES ACCORDING TO FOOD.    101
difference of effect.   In the former, such as that of
birds of prey, serpents, and fishes, no free or un-
combined acid can be detected, although it is inva-
riably 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 numerous 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 gradual change of diet, as  to fit
it for digesting aliment of a very dissimilar or oppo-
site 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 them.  In this way,  as is
mentioned by Delabere Blaine, a horse at the  Vet-
erinary College was supported for some time by an-
imal 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 ex-
tent 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

        * Blaine's Veterinary Art, 3d edit, p., 274.
                      12 
102        GASTRIC  JUICE VARIES
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  into 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 quantities 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 consid-
erable modifications, not merely according to the
kind of aliment habitually used, but also according
to the wants of the system, the season of the year,
and the state of the  health; so that, while sudden
and great changes from  one kind of diet to another
are positively hurtful on the one hand, absolute uni-
formity is not less objectionable on the other.
  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 analogous to it in effect.  From
the general results, it appears that acetic acid (vine-
gar) and muriatic acid have a wider range of  influ-
ence, and produce solvent effects more closely re-
sembling those of gastric juice, than any other known
substances.  Both of these acids, it will be recollect-
ed, are constituent elements of the gastric fluid ; and
it has* in consequence, been argued, that to them it is 
ACCORDING TO  FOOD.         103
        indebted for all its  energy.  And, indeed, without
        laying too much  stress on this  real or  supposed
        analogy, it is impossible to overlook the well-known
        fact, that scurvy, and a highly alkaline state of the
        system, are generally induced  by a diet restricted
        for a long time to animal  food alone, and are pre-
        vented or cured most easily by a free use of lemon-
        juice or of vegetable matter, either fresh or  fer-
        mented.   In these circumstances, 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 acid-
        ity is almost invariably induced by the use of vege-
        table food, possibly to some extent for the very pur-
t       pose  of  effecting  its digestion; for  it has been as-
        certained beyond  a doubt, that  in herbivorous ani-
        mals the gastric juice always contains some free or
        uncombined  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 fond-
        ness which the Germans and Dutch display for saur-
        kraut—or cabbage in a state of acetous fermenta-
        tion—and of its alleged easy digestibility.  It  ex-
        plains, also, the general use of vinegar along with
        salads, cucumbers, oysters, salmon, and other sub-
>       stances of difficult digestion, and shows that its util-
        ity is not imaginary, but loudly proclaimed by na-
        ture's own acts.
          Another important principle, which Dr. Beaumont
        conceives to be established by his numerous exper-
        iments, and which forced  itself  upon him by  de-
        grees, is, that in health the  gastric secretion al-
        ways BEARS A DIRECT RELATION TO  THE QUANTITY OF
        A.LIMENT  NATURALLY  REQUIRED BY  THE SYSTEM;   SO
        thai, if more than this be  taken, there  will neces-
        sarily be too small a supply of the juice for the di-
        gestion of the whole.   The principle here laid down 
104      GASTRIC  SECRETION  VARIES
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
presumption of its truth.   When, for example, we
eat more than the wants of the system require, in-
digestion will follow, because there will be more
food in the stomach than what the quantity of gas-
tric juice provided is able to dissolve; the propor-
tion 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  ex-
ceeded.   Here a remarkable harmony will be per-
ceived  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. 35).
  The gastric secretion, and the appearance of the
villous coat, undergo great modifications during dis-
ease, and on this subject also Dr. Beaumont's  ob-
servations are highly valuable ; because, instead of
merely inferring, as others are obliged to do, he  en-
joyed the privilege of seeing with  his  eyes what
was actually going on.  In the course of his attend-
ance on St. Martin, he found that, whenever a fever-
ish state was induced, whether from  obstructed per-
spiration, from  undue excitement by stimulating li-
quors, from overloading the stomach, or from fear,
anger, or other mental emotion depressing or dis-
turbing  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 ap-
pearance.   As  a necessary consequence, the usual
secretions  became vitiated, impaired, or entirely
suppressed; and the follicles from which, in health,
the mucus  which protects the tender surface of the
villous coat is poured out, became flat and flaccid, 
        AND  IS  DEFICIENT  IN DISEASE.    105

and no  longer yielded their usual bland secretion.
The nervous and vascular papillae, 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, showed  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
importance;  and from the care with which Dr.
Beaumont pursued his investigations, 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, nause.a, and uneasiness generally felt in
the region of the stomach, but show the folly of at-
tempting to sustain strength by forcing the patient
to eat when food cannot be digested, and when na-
ture instinctively refuses to receive it.

  Before dismissing this part of the subject, it may
be  remarked, that the alleged sympathy of the
stomach with the wants of the body has  been de-
nied, because the  sense of hunger disappears the
moment food is  swallowed, or the  stomach is dis-
tended  even with clay or sawdust,  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 noiv  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  to 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 therefore, when distended, expresses con- 
 106   DIFFERENT THEORIES OF  DIGESTION".

tent, because it feels satisfied that it has been  hon-
estly dealt with, and got what it wanted.  But when-
ever it discovers the cheat, which it does in no long
time, hunger returns, and can be properly appeased
only by digestible  substances.   Dr. Beaumont in-
deed expressly mentions, that, although the gastric
secretion commences  the moment any indigestible
body 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.
                  CHAPTER V.

          THEORY AND LAWS OF DIGESTION.

Different theories of Digestion.—Concoction.—Fermentation.—
  Putrefaction.—Trituration.—Chymical solution.—Conditions
  or laws of digestion.—Influence of gastric juice.—Experi-
  ments illustrative of its solvent, power.—Its mode of action on
  different kinds  of aliment—beef, milk, eggs, soups, &c.—In-
  fluence of temperature.—Heat of about 100° essential to di-
  gestion.—Gentle and continued agitation necessary.—Action
  of stomach in admitting food.—Uses of its muscular motion.
  —Gastricrjuice 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 digesti-
  ble.—Farinaceous next.—Vegetables and soups least digesti-
  ble.—Organs of digestion simple in proportion to concentra-
  tion of nutriment.—Digestibility depends on adaptation of
  food to gastric juice more than on analogy of composition.—
  Illustrations.—No increase of temperature during digestion.—
  Dr. Beaumont's summary 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 
      EXPLODED  THEORIES OF  DIGESTION.  107

various theories  which  have prevailed  since  the
subject first attracted the attention of the learned.
  Hippocrates regarded digestion as a  kind of con-
coction, or stewing; and many of his followers be-
lieved that it is effected in the stomach by the agen-
cy 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 main-
tain that that agent alone will accomplish digestion.
  Others of the older physiologists contended that
chymification results from simple fermentation of
the alimentary mass, and referred to the gas disen-
gaged during difficult digestion, as a proof that the
process of fermentation  was going on.  But it is
now  demonstrated that the tendency of healthy di-
gestion is rather to arrest than to induce fermenta-
tion, and that the latter takes place only when dis-
ease exists, or when more food has been swallowed
than the quantity of gastric juice secreted  by the
stomach  is  able  to dissolve.  Moreover, the pro-
ducts of digestion and of fermentation are  so ex-
tremely different, that it  is impossible to  believe
them to originate from  the same chymical action.
  The next theory which prevailed considered di-
gestion 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 demon-
strate the wildness of such a supposition.
  Another set of physiologists imagined that tritu-
ration would account best for all the changes occur-
ring  in the food during  digestion ;  and consequently
regarded the chyme  as a  sort of emulsion  formed
by the intimate  mixture of the aliment with the
juices of the stomach,  just as an emulsion is form-
ed by rubbing down almonds in a mortar.   The ad-
vocates of this theory  referred for proofs not only
to the contractile motions of the stomach already
noticed, but to the muscular apparatus for tritura- 
 108   CHYMICAL THEORY OF  DIGESTION.

 tion which forms so remarkable a feature in the giz-
 zard of granivorous birds.  But, in  adopting  this
 conclusion, they forgot that in birds the triturating
 apparatus does not digest, but  serves, like the or-
 gans of mastication in man and quadrupeds, merely
 to bruise the grain on which the animal lives.   In
 birds, in fact, digestion begins only after the tritura-
 tion is finished.
  A more recent and much more accurate view of
 digestion is that which considers it as neither more
 nor less than a chymical 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 principles.   It is true,
 that by the agency of gastric juice on food out of
 the body, a change very  similar to chymification
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 form-
 ed, and that as yet we are acquainted with no purely
 chymical agent which, applied to different substan-
ces, gives rise to the same  uniform product, we shall
be more willing to  believe that chymification  is
 neither a purely mechanical nor a purely chymical
 operation^ but the result of a vital process, to which
 both mechanical and chymical forces  contribute,
 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, 01  ith-
 out which it  cannot be carried on.
   The first indispensable requisite is an adequate
 supply of gastric juice,  and its thorough admixture
 with every particle of the food on whichit is to oper-
 ate.  The  second is a steady  temperature of about
 98° or 100° Fahr.; and the third is the gentle and 
            CONDITIONS REQUIRED FOR DIGESTION. 109

        continued agitation of the alimentary mass in the stom-
        ach while digestion is going on.
          In illustration of the influence of the first con-
        dition, I may refer to the experiments already men-
        tioned as having been made by Spallanzani, Stevens,
        and others, to show the solvent power of the gastric
        juice on food even  out of the body.  Spallanzani
        states, that when small portions of well-masticated
        beef or mutton  are placed in a vial, with a due pro-
        portion of gastric juice, and the requisite tempera-
        ture and gentle  agitation are secured by placing the
        vial in the armpit, 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 im-
        portance of Spallanzani's  researches, and  of the
        almost universal adoption of his views by succeed-
        ing physiologists, till confidence 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 verifying 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 investi-
}       gations, of which the following is  an imperfect,
        though,  I hope, instructive abstract.
          To test the reality of the solvent powers ascribed
        to the gastric juice, Dr. Beaumont withdrew from
        St. Martin's stomach about one ounce of it, obtained
        after a seventeen 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
                              K 
 110     ACTION OF GASTRIC JUICE ON

 had previously ascertained to be the heat of the
 stomach when  the  secretion was  going on.  In
 forty minutes, digestion  had distinctly commenced
 on the  surface of the beef.  In fifty minutes, the
 fluid became quite opaque and cloudy, and the tex-
 ture 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  undissolved.  In
seven hours, the muscular texture was  no longer
 apparent; and in nine hours, the solution was com-
pleted.
  To compare the progress of digestion in the nat-
ural way with these  results, Dr. Beaumont, at the
time of  commencing 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  completely di-
gested and disappeared, making a difference of
result in point of time of nearly seven hours.  In
both, the solution began on the  surface,  and agita-
tion accelerated its progress  by removing the ex-
ternal coating of chyme as fast as  it was formed.
When the  experiment was repeated with chicken
instead of beef, the solution was slower, from the
greater  compactness of  the chicken not allowing
the gastric fluid to penetrate its substance so readily"
Had the beef and chicken been masticated before
being subjected to experiment, the  difference be-
tween them in the rapidity of digestion would proba-
bly have been less.
  To ascertain still more accurately the difference
between natural and artificial digestion (the one m
and the other out of the stomach), Dr. Beaumont put 
      SUBSTANCES OUT OF THE STOMACH.   Ill

twelve drachms of recently-salted boiled beef into a
vial, with the same number of drachms of fresh gas-
tric juice obtained through the opening of the stom-
ach after a fast of eighteen hours; and then placed it
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 commenced, and progres-
sed 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 frequently seen in cases of indigestion.
On weighing the undissolved portion which remain-
ed 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, stom-
achic disorder must necessarily follow.  In this lat-
ter case, Dr. Beaumont 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 nega-
tiving the  common  notion  that  an hour elapses
before it begins.  The vial was now placed in  a
water-bath,  at a temperature of 100°, and continued
there for five hours.   Examined at the end of that
time, the whole contents were found to be dissolved. 
112  MODE OF ACTION OF GASTRIC JUICE.
 On then extracting an equal quantity 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 somewhat
 more rapid  in than out of the stomach.   But this
 experiment  is remarkable in another point of view,
 as showing  that in the short  space of twenty min-
 utes enough of gastric juice had been secreted for
 the entire completion of digestion.
  With a view to verify these results, and also to
 discover the comparative digestibility of different
 kinds of aliment, 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 fifteen  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 pulpy, and the fluid  containing it had be-
 come more  opaque and  gruel-like  in appearance.
When two hours had elapsed, a third quantity was
taken out, at which  time nearly all the  meat had
become chymified and changed into a reddish-brown
fluid; but  small pieces of vegetable matter now  pre-
sented 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 treated in the usual way, advanced to com-
plete digestion, as in the other experiment, except
 that the process  was slower, and that a few vegeta-
ble  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
 according to the nature of the  food on which it acts 
    ACTION OF GASTRIC JUICE ON LIQUIDS. 113

We have seen that it gradually reduces solids to a
soft and fluid state ;  but its effect on milk and albu-
men is different.  It begins by coagulating them,
so as to give them the, requisite consistence for
being affected by the muscular 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 by Dr.
Beaumont presented the appearance of a fine, loose-
ly-coagulated substance, mixed with a semi-trans-
parent 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 twenty minutes.  In another experi-
ment, when four ounces of bread were given along
with a pint of milk, and the contents were examin-
ed at the end of thirty minutes, the milk was coagu-
lated, and the bread reduced to a  soft, pulp floating
in a large  proportion of fluid.  In two hours the
whole was completely  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 assumed an opaque whitish ap-
pearance.   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 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.
Fifty  minutes after St. Martin had dined on vegeta-
ble 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  absorbed to such an
                      K 3 
114 ACTION OF GASTRIC JUICE ON VEGETABLES.

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 soup and liquids cannot be di-
gested until 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 stomachs,
and the impropriety of large libations of tea or cof-
fee at breakfast by persons whose  digestion is bad.
During recovery from  illness, chicken-tea, beef-tea,
and soups are often useful, simply because the sys-
tem  then requires the  liquid  to make  up its lost
blood.
   Unfortunately, Dr. Beaumont made few experi-
ments on the action of gastric juice upon vegeta-
bles ; and, in the few recorded, he generally con-
tents himself with noting the length of time required
for their solution,  which generally proved consid-
erably longer thai* 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 eats acescent fruits or vege-
labh-.s."   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 irri-
tated appearance.   WTith  farinaceous vegetables,
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 gas-
tric contents, nor  smarting of the edges of  the
wound:  on the contrary, it seemed peculiarly grate-
ful to the stomach, and rendered the mucous mem-
brane soft, uniform, and healthy. The same results
followed a repetition  of the exjieriment, and also 
INFLUENCE OF TEMPERATURE.    115
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 ali-
ment.

  Such being the influence of gastric juice on differ-
ent 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 portions, 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, con-
taining the same weight  of  masticated meat in an
ounce of clear water.
  In two hours the meat  in the  warm vial was par-
tially 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 far-
ther alteration.  The gastric juice  in the first vial
having by this time dissolved as much as it could of
the beef, four drachms more were  added from the
stomach,  and the vial was replaced in the bath.
Digestion, which had previously  ceased, was now re-
sumed, and went on as steadily as if it had not been
interrupted;  thus showing, 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 por-
tions were examined.   That contained in the warm
juice was completely dissolved, and presented the
usual appearances.  The portions contained  in the 
 116  INFLUENCE OF MUSCULAR CONTRACTION

 cold juice and in the cold water very much resem-
 bled each other, and exhibited  no appearance of
 chyme whatever.  They were macerated or soften-
 ed, but not digested..  These experiments, and others
 of a similar nature, show clearly that a temperature
 equal to ordinary blood-heat is requisite for chymi-
 fication.
  To make  sure that it  was the low temperature
 alone which prevented the occurrence of digestion
 in the experiment detailed, Dr. Beaumont now placed
 the vial containing the meat which had been exposed
 without effect for twenty-four hours to the action of
 the cold gastric  juice, on a water-bath at the ordi-
 nary 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 essentiality of heat to the digestive process.

  Thirdly.—The necessity of gentle and continued
 agitation for the  accomplishment of digestion is so
 obvious from the preceding exposition, that it re-
 quires no direct experiments to establish it.  When
 portions of meat were suspended in the stomach, bv
 a string so short  as to prevent them from being fully
 subjected to the motion already 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 por-
 tions below.  Accordingly, when, in one of Dr. Beau-
 mont's experiments, two ounces  of unmasticated 
OF  THE  STOMACH  "N  DIGESTION.    117
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 acquaint-
ed 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  ar-
rangements by which they are respectively and un-
erringly 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
seereted  bears a  direct  relation to the quantity  of
food consumed;  that when the food exceeds consid-
erably  the real necessities of the system, a part,of
it remains undigested, because the stomach is una-
ble to  secrete a sufficiency of fluid for the solution
of the  whole;  and that, as a necessary  conse-
quence, indigestion follows.  This being the case,
we may expect to find all the arrangements of na-
ture 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 mastica-
tion, insalivation, and deglutition, are not only use-
ful  in  preparing the morsel for the future action  of
the gastric juice, but, by transmitting the  food  to
the stomach in small portions  at a time, likewise 
118 INFLUENCE OF MUSCULAR CONTRACTION

serve the  important secondary  purpose of prevent-
ing 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 con-
traction 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 Ameri-
can  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 stom-
ach  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 therefore confirmed rather
than refuted by what may at  first appear an ex-
ception.
  When Dr. Beaumont depressed  the valve in  St.
Martin's stomach, and introduced a few  spoonfuls
of soup at the orifice, he observed the rugae or folds
of the mucous membrane 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 relaxa-
tion 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 
       OF THE STOMACH ON DIGESTION.    119

were  excited, and  continued from  fifty to eighty
seconds,  so as to prevent more from being intro-
duced without considerable  force till the contrac-
tion 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 he 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
observed to take place ; and till this was  over, a
second morsel could not be received without a con-
siderable  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 reg-
ular 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 secre-
ting  vessels of the  stomach, the moment the ali-
mentary  morsel  comes  into contact with the mu-
cous membrane,  the action  of the  latter, as was
formerly pointed out, becomes increased ; its blood-
vessels  are distended,  its  colour  deepens to  a
brighter  red, and the  gastric  juice  immediately
begins to be poured out.  The muscular fibres of
the stomach, being  acted upon by the same stimu-
lus, next come into  play, and execute their specific
functions of alternate  contraction and relaxation.
By these means the aliment  speedily becomes im-
pregnated with the  gastric fluid, and undergoes the
influence 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 
120  ADMIXTURE OF FOOD AND GASTRIC JUICE.
of gastric juice necessary for its  solution.  The
particles of food are  thus continually changing
place, and if the quantity taken be not too great for
the power of the gastric juice which  the stomach
can supply, chymification goes on equally through-
out ; 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 con-
sist 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  itself.  So effectually in-
deed 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 stom-
ach 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 by the  muscular  contractions of the
stomach, which renders fluid and highly concentra-
ted nourishment, when exclusively used, so  difficult
of digestion; and hence the reason  why a  certain
bulk and consistence given to whale oil, for exam-
ple, by the admixture of  such innutritious substan-
ces as vegetable fibre, bran, or  even  sawdust, make
it  a more acceptable 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 nu-
triment which they  contain. Soups, jellies, arrow-
root, and similar substances, are, for the same rea-
son, more easily digested when eaten along with
bread or  some  bulkier aliment, than when taken
alone,  especially if  used for some time. 
   ADMIXTURE  OF FOOD AND GASTRIC JUICE. 121

  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 diges-
tion proceeds, or the organ is distended, it becomes
more rapid and energetic;  and then it serves the ad-
ditional purpose of gradually propelling 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 peculiar situation of the stomach, greatly
assisted by the play of the diaphragm and abdom-
inal muscles  during inspiration  and expiration;
and the  diminution of the vivacity and  extent of
the respiratory movement which always  attends
despondency and grief, is  one source  of the enfee-
bled digestion  which notoriously  accompanies or
follows depression of mind.   The  same cause also
leads necessarily  to  an unfavourable condition of
the blood  itself,  which in its turn weakens diges-
tion 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  buoyancy 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 added  the
increase of nervous stimulus which pleasing emo-
tions occasion in the stomach (as in  the muscles,
and organs of  secretion generally), we shall have
no difficulty in perceiving why digestion goes on so
well in parties where there  is much jocularity and
mirth.  "Laughter,"  says Professor  Hufeland of*
Berlin, " is one of the greatest helps to digestion
with which I am acquainted; and the  custom prev-
alent among our forefathers, of exciting it at table
by jesters and  buffoons, was  founded on true medi-
cal principles.  In a word, endeavour to have cheer-
ful and  merry companions  at  your  meals: what 
122   ACTION OF GASTRIC JUICE ON FOOD.
 nourishment one  receives amid  mirth and jollity
 will certainly produce good and light blood."*
   Exposed  to  the action of all the agents above
 enumerated, and to the increased' nervous and vas-
 cular excitement which are necessary during diges-
 tion,' 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 con-
 verted 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 immedi-
 ate contact; and, in proportion as it is produced, it
 is carried gradually onwards by the gentle motion
 of the stomach towards the pylorus, where conse-
 quently 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 re-
 moved from it  and carried away towards 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 proper 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,  whatever 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. Mar-
 tin,—and such, he naturally infers, is not the order
 in the human stomach in general.   Nor is such I
  * Art of Prolonging  Human Life, English  edition. London
 1829, p. 282.                                     ' 
     ACTION OF GASTRIC  JUICE  ON FOOD. 123

may add, the order which either experience or a
correct  view of the antecedent circumstances and
physiological conditions ought to lead us to antici-
pate.  When vomiting, for instance, occurs an hour
or two after a meal composed of different ingredi-
ents has been swallowed, no such separation into di-
gested and undigested portions is to be found, but the
whole are observed to have undergone changes pro-
portioned to their degrees of digestibility, whether
they were eaten first or last.
  In conformity with this view, Dr. Beaumont men-
tions, that when St. Martin swallowed a mouthful
of any tenacious food after the digestion of the pre-
ceding meal was considerably advanced, he always
saw it first pass towards 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. Beaumont infers, that " there is a perfect admix-
ture of  the whole ingestae during the period of ali-
mentation and chymification;" and that " the whole
contents of the  stomach, until chymification be near-
ly complete, exhibit a heterogeneous mass of solids
and fluids—hard and soft, coarse and fine, crude and
chymified—all intimately mixed, and circulating pro-
miscuously 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 state-
ments being correct.
   If  Dr.  Beaumont's observations on this subject
are  accurate, we may expect to find that chymi-
fication 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 sta-
ted by Dr. Philip.   Such,  accordingly, is the fact.
When Dr. Beaumont extracted a portion of the food 
 124  GASTRIC JUICE ACTS ON EVERY PORTION

 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 mix-
 ed 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 sta-
 ting, that the newly-swallowed food becomes imbed-
 ded in, and occupies the centre of, the  older  and
 half-digested  mass, where it  remains  distinct  and
 untouched till the former meal is entirely disposed
 of.  A more logical explanation, however, and one
 more in harmony with facts, is offered by Dr. Beau-
 mont, 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 compara-
tively exhausted, being unable to secrete  a fresh
supply for the second—seeing that, in ordinary cir-
cumstances, its vessels secrete only enough to meet
the real wants of the system.  Dr. Beaumont addu-
ces, in confirmation of this view, the fact that many
children, and most  cooks, are in the habit of eating
small quantities of food almost every  hour or  two
without their digestion suffering materially, because
then the amount of gastric juice secreted is quite
equal to  the chymification  of the whole  quantity
 lajvti'lj..
  Reasonable  as this inference appears from the
 facts stated by Dr. Beaumont, I cannot  help thinking
 that there is something more in the constitution of
 the stomach  than  the mere  deficiency of gastric
juice, which renders the too early intrusion 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 
OF FOOD  WHICH IT  TOUCHES.      125
feeble, and that, as chymification advances, they be-
come rapid and energetic, 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 it-
self an impediment, and co-operate with the defi-
ciency of the gastric juice in disordering digestion?
Moreover, as the stomach, in common with every
other organ  intended for alternate activity and re-
pose, is always more or less fatigued by the active
fulfilment  of its function, its premature excitement
by new food must add to its  exhaustion, and weak-
en its power (in the same way in which fresh mus-
cular exertion adds to the exhaustion of muscles al-
ready sufficiently exercised), and consequently lead
to imperfect digestion.
  The same principle which explains the necessity
of repose for repairing the vascular and nervous en-
ergy of the stomach, when these have been excited
and exhausted by the labour of digestion, also  af-
fords a solution of the  question why the appetite
does not return as soon as the stomach is empty,
but begins to be felt only after the stomach has en-
joyed a period of repose, varying in duration with
the mode of life, the state of health, and the nature
of the previous meal.
  If we regard chymification as going on at the sur-
face of every individual portion of the food which
has been sufficiently supplied with gastric juice, we
at once see that the constant motion of the stomach is
necessary, 1st, to remove the chyme from the sur-
face of each little fragment of the alimentary mass;
and, 2dly,  by this very removal to expose a fresh
surface of the fragment to the contact of the mu-
cous membrane, thereby enabling  it to excite such
farther secretion of gastric juice as may be requi-
red to complete its digestion.  In this way the for-
mation and removal of chyme go on from the very 
126
CONDITIONS  FOR  THE
first, although it is then necessarily produced and re-
moved 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 ear-
lier period, and is of opinion that, from the uniform
and constant decrease in the contents of the stom-
ach, which  begins as soon as  the food is swal-
lowed, chymification  commences " almost immedi-
ately.  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 gas-
tric fluid  also becomes greater, and affords a great-
er stimulus, in proportion as digestion advances.
  As  formerly explained, the thickish, semi-fluid,
grayish chyme, into which the aliment is converted,
is gradually impelled towards the pyloric extremity
of the  stomach, in proportion as  it is formed.  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 intes-
tine.  But, by a curious  mode of sensibility, if any
portion of undigested food be mixed with it, the py-
lorus contracts upon it, refuses it egress, and throws
it back into the stomach for farther digestion.
  If, however, any thing really indigestible finds its
way into  the stomach, and presents itself at the py-
lorus—or if the stomach has temporarily lost its di-
gestive power, and the food remains in it for many
hours unchanged—then  the pylorus,  after  repeat-
edly refusing egress, at last opens and allows it to
pass into the gut.  So marked is the contractile
impulse towards the pylorus when digestion is go-
ing on, that Dr. Beaumont found even the bulb of his
thermometer carried  down with a steady and con-
siderable force.
  Such are  the direct conditions requisite  for the
fulfilment of digestion: but there remain others, of 
       FULFILMENT  OF DIGESTION.         127

an indirect kind, which also require to be noticed.
Of these, a due supply of arterial blood and nervous
energy is the most remarkable ; but as both produce
their effect by modifying the secretions and motions
of the stomach, already described as the direct re-
quisites of digestion, it will save a good deal of rep-
etition if, for the present, we take their influence
for granted, and reserve their further elucidation till
we come to treat of the practical applications of the
preceding exposition.

  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 investi-
gation, immediately connected  with the process,
presenting itself—the comparative digestibility of dif-
ferent kind's of food.   Dr. Beaumont did not neglect
this branch  of tlie 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  condi-
tions which are known to exert a powerful influence
on the progress of digestion.
  The following table exhibits the general  results
of all the experiments made upon St. Martin poste-
rior to 1825 ; and the average is deduced from those
which were performed when the stomach was  con-
sidered by Dr. Beaumont  to be in its natural state,
and St. Martin himself subjected to ordinary exer-
cise. 
128  TIME REQUIRED FOR THE DIGESTION
TABLE showing the Mean Time of Digestion of the
            different Articles of Diet.
	Mode	Time re-
Articles of Diet	of	quired for Digestion.
	Preparation.	
		H. M.
Rice	Boiled	1
Sago . ...	Do.	1 45
Tapioca	Do.	2
Barley	Do.	2
Milk .	Do.	2
Ditto .	Raw	2 15
Gelatine	Boiled	2 30
Pigs' feet, soused	Do.	1
Tripe, soused	Do.	1
Brains.	Do.	1 45
Venison steak	Broiled	1 35
Spinal marrow	Boiled	2 40
Turkey, domestic	Roasted	2 30
Do. do.	Boiled	2 25
Do. wild	Roasted	2 18
Goose .	Do.	2 30
Pig, sucking	Do.	2 30
Liver, beef's, fresh	Broiled	2
Lamb, fresh	Do.	2 30
Chicken, full-grown	Fricassee	2 45
Eggs, fresh .	Hard boiled	3 30
Do. do. .	Soft do.	3
Do. do. .	Fried	3 30
Do. do. .	Roasted	2 15
Do. do. .	Raw .	2
Do. whipped	Do.	1 30
Custard	Baked	2 45
Codfish, cured, dry	Boiled	2
Trout, Salmon, fresh	Do.	1 30
Do. do.	Fried	1 30
Bass, striped, fresh	Broiled	3
Flounder do.	Fried	3 30
Catfish do.	Do.	3 30
Salmon, salted	Boiled	4
 
        OF DIFFERENT KINDS OF FOOD.     129




Table showing Mean Time of Digestion, continued.
Articled of Diet		Mode of	Time re-quired for
		Preparation.	Digestion. H. M.
Oysters, fresh		Raw .	2 55
Do. do.		Roasted	3 15
Do. do.		Stewed	3 30
Beef, fresh, lean, rare		Roasted	3
Do. do. dry .		Do.	3 30
Do. steak .		Broiled	3
Do. with salt only		Boiled	2 45
Do. with mustard, &c		Do.	3 30
Do. fresh, lean		Fried	4
Do. old, hard, salted		Boiled	4 15
Pork-steak .		Broiled	3 15
Pork, fat and lean		Roasted	5 15
Do. recently salted		Boiled	4 30
Do. do. .		Fried	4 15
Do. do.		Broiled	3 15
Do. do.	•	Raw .	3
Do. do.		Stewed	3
Mutton, fresh		Roasted	3 15
Do. do.		Broiled	3
Do. do.		Boiled	3
Veal, fresh .		Broiled	4
Do. do. .		Fried	4 30
Fowls, domestic		Boiled	4
Do. do.		Roasted	4
Ducks, do.		Do.	4
Do. wild .		Do.	4 30
Suet, beef, fresh		Boiled	5 3
Suet, mutton		Do.	4 30
Butter		Melted	3 30
Cheese, old, strong		Raw .	3 30
Soup, beef, vegetables			
and bread		Boiled	4
Do. marrow-bones		Do.	4 15
Do. beans»		Do.	3
Do. barley		Do.	1 30
Do. mutton		Do.	3 30
Green corn and be	ans	Do.	3 45
 
130    COMPARATIVE  DIGESTIBILITY  OF
Table showing Mean Time of Digestion, continued.
Articles of Diet		Mode of	Time re-quired for
		Preparation.	Digestion.
V			H. M.
Chicken soup - .		Boiled	3
Oyster soup		Do.	3 30
Hash, meat and vegetables		Warmed	2 30
Sausage, fresh		Broiled	3 20
Heart, animal		Fried	4
Tendon		Boiled	5 30
Cartilage		Do.	4 15
Aponeurosis		Do.	3
Beans, pod .		Do.	2 30
Bread, wheaten, fresh .		Baked	3 30
Do. corn .		Do.	3 15
Cake, do. .		Do.	3
Do. sponge		Do.	2 30
Dumpling, apple .		Boiled	3
Apples, sour and hard .		Raw .	2 50
Do. do. mellow		Do.	2
Do. sweet do. .		Do.	1 30
Parsnips		Boiled	2 30
Carrot, orange		Do.	3 15
Beet .		Do.	3 45
Turnips, flat		Do,	3 30
Potatoes, Irish		Do.	3 30
Do. do.		Roasted	2 30
Do. do.		Baked	2 30
Cabbage, head		Raw .	2 30
Do. with vinegar .		Do.	2
Do. do.		Boiled	4 30
  This table is very interesting, but the results must
not be too much relied upon, or regarded as repre-
senting the uniform rate of digestibility.  We have
already seen that chymification is greatly influen-
ced by the interval which has elapsed since the pre-
ceding meal, the  amount  of  exercise  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 
DIFFERENT KINDS OF FOOD.      131
circumstances ; and, above all, the quantity swallow-
ed in proportion to the gastric juice secreted.   And
consequently, if an experiment be made without re-
gard to these conditions, and without any thing be-
ing recorded except the time occupied 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 di-
gested in one third of the time.   Thus, in the fore-
going table, two and a half hours are  set down as
the average time required for the chymification of
jelly, but in the 41st experiment, 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 eacM trial, the results
cannot possibly be held as conclusive.
  It may be said that, on the day of the 41st exper-
iment, St. Martin's  digestion must have  been par-
ticularly good—and,  in truth, it seems to  have been
so; for at 9 o'clock  a. m. he breakfasted on soused
tripe, pig's feet, bread, and coffee, and yet, only 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 another
table at page 45, a  simple breakfast of coffee  and
bread is set down as having required four hours for
its digestion.  The  rapid disposal of the  same ele-
ments, 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 result
obtained from the experiment on one kind of food
cannot, with any show of reason, be considered as
an accurate index to its rate of digestibility in com-
parison with that of other kinds.
  This neglect of the other conditions is according-
ly the circumstance  which throws a doubt over the
results not only of Dr. Beaumont's experiments, but 
 132    COMPARATIVE DIGESTIBILITY OF

 of those of every other inquirer.   Dr.  Beaumont
 indeed candidly admits, that his were performed for
 the purpose of demonstrating other important prin-
 ciples 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 requisite's for a satisfactory
 series of experiments,  he himself justly states, that
 this would be an Herculean task, which it would take
 years to accomplish.   In considering the following
 general results, then, the  reader ought  to bear m
 mind that they are only probable and approxima-
 tive, and not strictly demonstrated or certain.

   As a general rule, animal food is more easily and
 speedily digestedj&nd contains a greater quantity of
 nutriment in a given bulk, than either herbaceous
,or farinaceous food; but, apparently from the same
 cause, it is also more heating and stimulating.  Mi-
 nuteness of division, and tenderness of fibre, are shown
 by Dr. Beaumont's experiments to be two grand es-
 sentials 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  stand-
 ard qualities.
   Farinaceous  food, such as rice, sago, arrow-root,
 and gruel, are  also rapidly assimilated,  and prove
 less  stimulating to the  system than  concentrated
 animal food. Milk seems to rank in the same class,
 when the stomach is in a healthy state.
   The other kinds  of vegetable substance are the
 slowest of all in undergoing digestion, and very fre-
 quently pass out of the stomach and through the
 bowels comparatively little changed; and hence the
 uneasiness which their presence so often excites in
 the bowels, especially in persons of weak digestion,
 owing to the nerves of the intestines having a rela-
 tion to digested food.   In a given bulk they contain 
DIFFERENT KINDS OF  FOOD.      133
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 person under-
going hard labour, they afford inadequate support.
  Liquids—soup, for example—are slow of diges-
tion, and hence are unfit for most dyspeptic  pa-
tients.  Before the gastric juice can act upon them,
the fluid  part must be absorbed, and the mass thick-
ened  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. Beaumont found that the absorp-
tion of the watery part had been carried so far as
to leave the remainder of even a thicker consistence
than after an ordinary solid meal.  When  drink is
swallowed, it is carried off in the same way by ab-
sorption, 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 nour-
ishment  in a small bulk, the apparatus of  organs
provided for  its digestion is on  a correspondingly
small scale in point of extent.  Thus, in carnivorous
animals,  whose food is, bulk for bulk, the most nu-
tritious 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 chapter, is greatly more complica-
ted, and the length of the intestines enormously in-
creased.  Man, being intended to feed on both ani-
mal and  vegetable substances, possesses an organ-
ization which holds an intermediate place between
                        M 
134      WHY ANIMAL FOOD  IS  MORE
the two extremes.   In him, neither are the intes-
tines so short as in  carnivorous animals, nor have
they the complexity and length characteristic of the
herbivorous—thus clearly, showing the intentions of
nature  in regard to his food, and at the  same time
allowing him a considerable latitude of  adaptation
when the force of circumstances for a time denies
him access to any variety.
  Animal food being in general more quickly digest-
ed than vegetable, and a simpler organization being
sufficient for its conversion into chyme, many phys-
iologists have inferred  that  this  was owing to its
being already of an animal nature, and therefore re-
quiring 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
..entirely analogous.  In  both, a  complete  solution
takes place, and the chyle into which animal food
is ultimately converted bears no greater resem-
blance to the future animal fibre, than does that pro-
duced 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 ultimate result of digestion is always
the  formation  of new  animal matter;  but in the
former case, the nutritive particles are mixed up
with a smaller proportion of innutritious 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 chymical
 composition of the chyle derived from different kinds
 of food; but its general nature—its fitness for form- 
DIGESTIBLE  THAN VEGETABLE.    135
ing new animal tissue—and that of the process by
which it is produced, are always the same
  Animal food, it is true, affords a more stimulating
nutriment than farinaceous and other kinds of vege-
table 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 aliment.
From the numerous experiments of injecting water,
poisons, and  other substances into the veins,  per-
formed  by Magendie and others,  we have direct
proofs that the same agent which, introduced rapidly
into the system, will sometimes  act so powerfully as
to destroy life, will excite scarcely any perceptible
disorder if introduced very slowly.  Analogy, there-
fore, bears us out in believing that  the rapid admix-
ture 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 na-
ture has rendered a certain bulk of food  advanta-
geous to digestion, and decreed that no animal can
long retain its health if fed on highly concentrated
aliment rSne.  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 reception  of highly concentrated
food.  Dr. Paris refers to post-horses fed chiefly on
beans and corn, as instances among the lower ani-
mals of the insalubrity of too condensed nutriment, 
136      WHY ANIMAL FOOD IS MORE
and shows that they live constantly on the brink of
active disease, 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 additional
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 Kamtschat-
dales  sometimes live with impunity for months on
fish-oil, by wisely mixing it up with sawdust or other
indigestible vegetable fibre.
  If the preceding explanation of the more rapid di-
gestion of animal than of vegetable substances, and
the higher stimulus which they afford, be correct,
the common notion, of the former being more digest-
ible than the latter solely because 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 nat-
ural state, in a temperate climate, animal food is
more  easily digested than vegetable, the fair infer-
ence ought rather to be that the system requires the
former in larger proportion than- the latter, and that
the gastric juice is purposely constituted with ref-
erence to this  circumstance.   Accordingly, in the
arctic  regions, where the  climate  renders  great
stimulus necessary, animal food,  of to us the  most
indigestible 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 di-
gestibility simply to its possessing " a composition
analogous to that of the  structure which it is de-
signed to supply," and therefore requiring "little
more than division and depuration," instead of the 
        DIGESTIBLE THAN  VEGETABLE.     137

alleged " complicated series of decompositions and
recompositions which must be effected before ve-
getable matter can be animahzed or 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 great-
est analogy of all to the structure of the body, must
require still less digestive power for its solution and
assimilation  than cooked  meat.  These  proposi-
tions, however, are wholly at  variance with experi-
ence :  in particular, the effect of cooking is unques-
tionably to induce a change of composition subver-
sive  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 qual-
ities of the gastric juice, and not from any such anal-
ogy  as that now alluded to, is rendered still more
probable by the  fact, that in  him the gastric fluid
contains scarcely any free acid, except where the
diet  has consisted for some time principally of ve-
getables ;  whereas  it always  contains a considera-
ble proportion of acid in herbivorous creatures.  In
the latter, moreover, the analogy is quite  as great
between animal substances and their own structure
as in man, and yet to a cow, beef is much more in-
digestible than grass, notwithstanding the " decom-
positions  and recompositions" which  the  latter is
supposed  to require before  becoming animalized.
Dr. Beaumont is therefore quite justified in maintain-
ing, that the process of digestion implies as complete
a solution and recomposition in the  case of animal
as of  vegetable substances;  and  that the  rapidity
with which the chymification 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  of its own composition
to that of the body of which it is to become a part.
               * Paris on Diet, p. 93.
                      M2 
 138 HEAT OF STOMACH DURING DIGESTION.

  Another prevalent notion—that the digestive ap-
 paratus 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 con-
 stituent elements of whose food there is no such
 analogy, the intestines nevertheless scarcely exceed
 in length those of carnivorous birds—a circumstance
 at variance with the notion of length being neces-
 sary solely on  account of the great elaboration re-
 quired for the conversion of vegetable into animal
 substance. The true principle—and it is  important
 to notice it, as the error is generally adopted—ap-
 pears 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 requisite 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 in
 creased surface of the intestine, or, in other words,
 on the greater calibre  of  its cavity; whereas, in
some fishes which live  on very concentrated  ali-
ment, the intestinal canal is  not much more than
the length of the body—thus showing that the com-
 mon opinion on the subject  is utterly untenable.

  Before concluding his experiments on the agents
 employed in digestion, Dr. Beaumont made many
 observations with  a view to ascertain whether any
 increase of temperature occurred during that pro-
 cess.   By introducing a thermometer with a long
 stem at the external opening into St. Martin's stom- 
   dr. beaumont's general inferences. 139

ach, both before and during chymification, he suc-
ceeded in obtaining very accurate information on
this 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 appeared, how-
ever, that the variations of the atmosphere produced
a sensible change on the heat of the stomach—a
dry air increasing and a moist air diminishing  it.
The ordinary temperature maybe 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
94o, 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 cleai
and  cold, to 100°.   On several occasions it rose  aa
high as 102°, and once to 103° ; but these were aftei
exercise, which was always  observed to cause an
increase of two or three degrees.  We have already
seen that artificial digestion is entirely arrested by
cold, and is resumed 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 Amer-
ican 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 infer-
ences 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 with-
out reference either  to logical sequence or to time. 
140 DR. BEAUMONT S GENERAL INFERENCES.

INFERENCES FROM DR. BEAUMONT'S  EXPERIMENTS AND
                  OBSERVATIONS.*

 1. That hunger is the effect of distention of the ves-
      sels that secrete the gastric juice.
 2. That the process of mastication, insalivation, and
      deglutition,  in an  abstract point of view, do
      not  in  any way affect the digestion  of the
      food; or, in other words, when food is intro-
      duced  directly into the stomach in a finely
      divided state, without these previous steps, it
      is as readily and as perfectly digested as when
      they have been taken.
 3.  That saliva does not possess the properties of
      an alimentary solvent.
 4.  That the agent of chymification is the  gastric
      juice.
 5.  That the pure gastric juice  is fluid, clear, and
      transparent; without odour; a little salt; and
      perceptibly acid.
 6.  That it contains free muriatic acid, and some
      other active chymical principles.
 7.  That it is never found free in the gastric cavi-
      ty ; but is always excited to discharge itself
      by the introduction of food or other irritants.
 8.  That it is secreted  from vessels distinct  from
      the mucous follicles.
 9.  That it is seldom obtained pure, but  is gener-
      ally mixed with mucus, and sometimes with
      saliva.  When pure, it is capable  of being
      kept for months, and perhaps for years.
10.  That it coagulates albumen, and afterward dis-
      solves the coagula.
11.  That it checks the progress of putrefaction.
12.  That it acts as a solvent of food, and  alters its
      properties.
13.  That, like other  chymical agents, it commences

  *  The  inferences are given in Dr. Beaumont's own words.
and the italics also are his. 
   dr. beaumont's general inferences. 141

      its action on food as soon as it comes in con-
      tact with it.
14. That it is capable of combining with a certain
      and  fixed quantity  of food, and when more
      aliment is presented for its action than it will
      dissolve, disturbance of the stomach, or " in-
      digestion," will  ensue.
15. That its action is facilitated by the ivarmth and
      motions of the stomach.
16. That it becomes intimately mixed and blended
      with the ingestae in the stomach by the mo-
      tions of that organ.
17. That it is invariably the same substance, modified
      only by admixture  with other fluids.
18. That the  motions pf the stomach produce  a
      constant churning of its contents, and admix-
      ture  of food and gastric juice.
19. That these motions are in two directions, trans-
      versely and longitudinally.
20. That no other fluid produces the same effect on
      food that gastric juice does ; and  that it is
      the only solvent 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 digestion ih&n 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
      chymical distinctions.
25. That digestion is facilitated by minuteness of di-
      vision and tenderness of fibre; and retarded by
      opposite qualities.
26. That the ultimate principles of aliment are al-
      ways the same, from whatever food they
      may be obtained.
27. That chyme is homogeneous, but variable in its
      colour and consistence. 
 142  dr. beaumont's general inferences.

 28. That, towards the latter stages of chymification,
       it becomes 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 stom-
       ach 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 excess, if persevered in, gen-
       erally produces  not only functional aberra-
      tion, but disease of the coats of the stomach.
36. That bulk as well as  nutriment is necessary to
      the articles of diet.
37. That bile is not ordinarily found in the stomach,
       and is not commonly necessary for the diges-
      tion 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
       contains  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 100Q Fahrenheit. 
dr. beaumont's general inferences. 143
42. That the temperature is not elevated by the in-
      gestion of food.
43. That exercise elevates the temperature ;  and that
      sleep or rest, in a recumbent position, depres-
      ses it.
44. That gentle exercise facilitates  the digestion of
      food.
45. That the time required for that purpose is vari-
      ous, depending upon the quantity and quality
      of the food, state of the stomach, &c.; but
      that the time ordinarily required for the dis-
      posal 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, but are here
omitted, because they refer exclusively to the chyle,
which has not yet been treated of.  The second and
seventeenth are, perhaps, too strongly  expressed.
A  complete  change of diet,  for example, causes
some variation in the gastric juice, although the lat-
ter inference, taken in a hteral sense,  affirms the
contrary 
144
NATURE OF CHYLIFICATION
                 CHAPTER VI.

 CHYLIFICATION, AND  THE ORGANS CONCERNED IN IT.

Chylification.—Not  well known.—Organs concerned in it.—
  The intestinal canal.—Its  general  structure.—Peritoneal
• coat.—Mesentery.—Muscular coat.—Uses of these.—Air in
  htestines.—lises of.—Mucous coat.—Analogous to skin.—
  The seat of excretion and  absorption.—Mucous  glands.—
  Absorbent vessels.—Course of chyle towards the  heart —
  Nerves of mucous coat.—Action of bowels explained—Indi-
  vidual structure of intestines.—The Duodenum—Jejunum—
  and Ileum.— Liver and  pancreas concerned in  chylifica-
  tion.—Their situation and uses.—Bile, its origin and uses.—
  The pancreas.—Its juice—The jejunum described.—The il-
  eum — 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 opera-
tion  which, as we have seen, takes place in the stom-
ach,  is  only one of  the  series of changes  which
aliment undergoes before becoming fit to be assim-
ilated with the living body;  and the next  process
which we have to notice is chylification, or 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 duode-
num, or beginning of the small intestine.   On its ar-
rival 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 sys-
tem, and forms nutriment,—and the other a yellow-
ish and  more consistent mass, which is  the indi-
gestible remains of the food, and which, after travers- 
NATURE OF  CHYLIFICATION.      145
ing the whole length of the intestinal canal, and being
there mixed with the waste matter separated 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 chylifi-
cation, or intestinal digestion.  The organs concern-
ed in the latter are so deep-seated and inaccessible
during life, that very few opportunities occur of ob-
taining accurate information on the subject; and,
therefore, in what  follows, I shall  not enter into
disputed or intricate details, but confine 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 prac-
tical importance than  if it extended to stomachic
digestion also ;  because such is  the harmony be-
tween all the parts of the system,  that whatever
conduces to the perfect accomplishment of the first
stage of the process, chymification, is in so far equal-
ly conducive to the proper fulfilment of  chylifica-
tion, or intestinal digestion.
   The simple fact, indeed, of our having  no direct
control over  the process of chylification, and of our
being able to modify it only by varying, through the
medium of the stomach, the elements out  of which
chyle is to be formed and the mode in which they
shall be digested, is  a proof that, practically speak-
ing, it is chiefly the laws or conditions  of stom-
achic digestion which are intended to regulate our
conduct; and that, in  obeying them, we in reality
 obey also those of intestinal digestion.

   The  organs concerned in chylification are  the
duodenum, the liver, and the pancreas ; but in order 
146
INTESTINAL  CANAL.
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 real,
but it still continues to be  made on account of its
convenience.
  The first grand division is into the small and great
intestines;  the former beginning at the stomach,
including all the convolutions marked RSSSS,—and
the latter beginning at T, where the small intestine
terminates, and including the large gut UUUUXYY,
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 cacum, or simply the cacum, 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 analo-
gy 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 in-
ternal, 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 abdo-
men.  It serves both  as a support and as a medium 
 
 148    INTESTINE--PERITONEAL COAT.

 of attachment to fix the intestine in its place.   By
 its  smooth, soft, and lubricated surface, it admits
 readily of the change of place among the bowels
 necessarily produced by respiration, exercise, and
 even by different degrees of distention of the bow-
 els themselves.   Every time we breathe an undu-
 lating  motion is  communicated to the whole intes-
 tines, which facilitates their action, but which could
 not take place unless they were capable of gliding
 easily and freely over each other.  The peritoneal
 coat, being strong, extensible, and elastic, is very
 useful  also as a support to the other coats.
  The peritoneal coat, after  forming the outer cov-
 ering  of the intestine, represented by the dotted
 line round the circle I in the figure on next page,
 is continued from it in the form of a double mem-
brane (represented by the two dotted lines) towards
the spine S, to which it is first firmly attached by
cellular substance ; after which the folds again sep-
arate, each being continued, or reflected, as it is call-
ed, over the whole inner substance of the cavity of
the abdomen in  the course shown by the dotted
line, the figure itself representing a transverse sec-
tion of the abdomen.   By  this arrangement two
important objects are attained.   First, the abdomi-
nal peritoneum AP forms a soft lubricated surface,
corresponding  to that of the bowels  themselves;
and, secondly, a  firm  point of attachment  for the
bowels is secured, by-which  they may be supported
in their proper places, and at the same time admit
of some change  of position.  The floating portion
 of the  peritoneum, M, by which the attachment is
 effected, is called the mesentery (from pe„oS, mesos, the
 middle, and evrepov, enteron, intestine).   But the in-
 testinal canal being so much longer than the por-
 tion of the spine to which the mesentery is attach-
 ed, the  latter js necessarily disposed  in folds
 converging towards  the spine,  something like the
 folds of a fan converging towards its  narrow end 
         INTESTINE—THE  MESENTERY.     149

In this  way  the  mesentery, 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 small intestines.  This
feature, however, will be better understood by in-
specting the wood-cut on page 151, representing a
portion of the bowel II, as attached to the spine by
the mesentery MM, along which the absorbent ves-
sels or lacteals  LL are seen to pass from the gut
towards the thoracic duct TD.
  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 ob-
ject here, as elsewhere,  is to effect motion.  By the
alternate contraction of the two kinds  of fibres,
the contents of the gut are  gradually propelled in a
downward direction, just as we see a motion prop-
agated from one end of  a worm to the  other ;  and
hence it is sometimes called  the vermicular  motion
(from vermis, a worm).  Some nauseating substan-
ces, such as emetics, have  the power  of inverting
the order of the muscular contractions, and direct-
                     N2 
 150  INTESTINE--THE MUSCULAR  COAT.

 ing the  contents upwards instead of downwards—
 whence vomiting ultimately arises.   Other substan-
 ces, again, have the property of exciting the natural
 action to a higher degree, and consequently propel-
 ling the contents faster downwards—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 obvia-
 ting the kind of costiveness which arises from im-
 perfect intestinal contraction.   In a natural mode
 of life, the  muscular  coat  is greatly aided in its
 operation by the large  abdominal and thoracic mus-
 cles, brought powerfully and'frequently into play
 during active exercise and employments.   When
 this aid  is withdrawn, 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 ex-
pansion  of the chest, and corresponding motion of
 the abdomen, altogether impossible, and thus aggra-
vates 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 prefer-
 ence to  those of a saline nature, which act chiefly
 by  stimulating  the mucous surface to farther se-
 cretion.
  In addition to the ordinary longitudinal and trans-
 verse fibres, the colon presents three remarkable
 muscular bands running along its whole length, and
 one of which is represented on the colon in the figure
 oh  page  140.  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 
     INTESTINE--THE  MUSCULAR COAT.   151

contract, it may naturally be  supposed that, after
the intestine is emptied, its opposite sides will come
into  contact, and, y 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 con-
siderable 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 mus-
cular contraction itself.  Air, in fact, by its expan-
sive energy, forms the antagonist power to the mus-
cular 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 contraction, but is use-
ful in facilitating the passage of the subsequent por-
tions of the feculent matter ;  and hence the  injec-
tion  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 intes-
tine, 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  in-
creased in extent, so as to afford ample space  for
the ramification of the bloodvessels, nerves, and ab-
sorbents, with which it is very plentifully supplied.
The cut on p. 161 will convey some idea of its ap-
pearance, 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  di-
rect contact with the chyme, and in its cavity the 
152       INTESTINE--MUCOUS COAT.
bile and pancreatic juice perform their respective
parts, 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 commu-
nicating the power of propelling its contents.
  The mucous coat appears, on examination, to be
so entirely 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 be-
tween them is  well known to be  very rapid and in-
timate.  Eruptions on the skin, for example, are al-
most always owing to disorder of the digestive or-
gans ;  and bowel-complaint, on the other hand, is
often produced by a sudden chill on the surface.  In
like manner, in enormous eaters like those formerly
mentioned, an immense exhalation takes place from
both the skin and the bowels, and in many instan-
ces the one supplies the place of the other in a con-
siderable degree.   We have seen, moreover, that in
the lowest tribes of animals, the digesting surfaces
and skin are not only undistinguishable, but actual-
ly  convertible 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 any thing else.
  In common with the skin, too, the mucous coat is
charged with the double function of excretion and
absorption.  For the former, it is eminently fitted by
its plentiful supply of blood, and by the great num-
ber 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 feces or ex- 
    INTESTINE--MUCOUS COAT--ITS USES.  153

crement.  When the blood is suddenly repelled from
the surface  by a chill, and thrown in upon these
vessels  in large quantity, the  natural excretion is
sometimes increased to such an extent as to con-
stitute bowel-complaint;  while at other times, that
peculiar form of action is induced which constitutes
inflammation.  The local stimulus of some kinds of
food, and of many medical substances, also  excites
the secretion  to  unusual activity.   Salts,  for in-
stance,  have this  effect, and thus often produce nu-
merous  fluid evacuations, the substance 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 lodging 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 saline purgatives are  so useful for
lowering the tone of the system when that is requi-
red ; but, for the same reason, they are most im-
proper where  relaxation  and debility already exist.
In the cholera, almost the whole fluids of the body
are 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
ramified 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.  Occasionally, however,
the mucous secretion becomes  so abundant and vis-
cid 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
common, and  cannot be expelled  except by reme-
dies 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 absor- 
154 INTESTINE—MUCOUS COAT—ABSORBENTS.

bents, are ramified on its internal surface, the nature
and purposes of which are analogous to those men-
tioned  in the former volume when describing the
functions of the skin.*  In both structures the ab-
sorbents 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 absor-
bents, or simply the lacteals, or milk-vessels (marked
LL in the subjoined wood-cut), from the white col-
                     TD
                      !
our 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:
* Principles of Physiology, &c, chap. ii. 
 INTESTINE—MUCOUS  COAT--ABSORBENTS.  155

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 serve  chiefly to  remove the more
watery portions of the intestinal contents, by which
means the feces are  rendered more  solid  and less
bulky, and therefore better adapted for being retain-
ed for a time without inconvenience.  It sometimes
happens  that, when food or medicine cannot be
swallowed in the usual way, life is preserved by in-
jecting  it into the bowels; in which case the ab-
sorbents of the large gut become  active, and carry
it into the system. Opium laxatives and other rem-
edies are often administered 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 colour-
less, and hence in other places they are called lym-
phatics :  in almost every other respect,  however,
the two  classes of vessels are analogous to each
other.
  The peculiar property by which the  minute  lac-
teal vessels take up the white chyle is not well un-
derstood. From the fact in physics that liquids rise
in capillary  tubes, the  inference  has been  drawn
that absorption  in living vessels  also  takes place
from capillary attraction.  But in the animal body
the application of the principle is undoubtedly mod-
ified by the properties peculiar to  organization, and
one of the most remarkable proofs of this is the cir-
cumstance of the absorbent vessels  in different sit-
uations 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 adap-
tation was so complete  that every absorbent  vessel
was permanently shut to every thing except its own 
156  INTESTINE--MUCOUS COAT--ABSORBENTS.
 peculiar object, and that, from amid many elements,
 each selected its own with unerring tact.  But of
 late 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
 mixing madder with the food  of fowls, for example,
 for the purpose of dying their bones, the colouring
 matter of the root is ta-               _.
 ken up without difficulty
 by the absorbents along
 with the chyle, although
 madder  was   certainly
 never intended to be their
 natural  stimulus.   But
 even admitting this lati-
 tude in its fullest extent,
 there still exists a fitness
 and peculiarity  of  rela-
 tion between the absor-
 bents and their proper ob-
 jects, which renders the
 latter more accessible to
 them than any  foreign
 body.
   The lacteal vessels are
 most easily seen an hour
 or two after a meal; be-
 cause they are then fully
 distended  with  chyle,
 even  in  their  smaller
 branches.  The latter, in-
 deed, may then be  dis-
 tinctly traced proceeding
 from the  different por-
 tions  of  intestine,  and
 gradually coalescing into
 larger trunks, as seen at
 LL in the figure on p. 154.
 
     INTESTINE--COURSE OF THE CHYLE.   157

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
almost in a direct course along the spine, and which
is represented at DBDD in the preceding  cut.  On
its arrival at the upper part of the chest, the thora-
cic duct crosses over and opens into the 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
absorbents, in their  progress  from the intestine to
the thoracic duct, pass through the small  glandular
bodies called  the mesenteric glands (M. G. p. 154),
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, nu-
trition is  greatly impaired, although the  appetite
and stomachic digestion remain comparatively un-
affected.
  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 into blood ; and this can be effect-
ed only by exposing it to  the,action of the air, in
the air-cells of the lungs, in a state of intimate mix-
ture 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 
158           BAD AIR HURTFUL.
   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 pure air without, the result
   is invariably injurious to health;  because the blood,
   being no longer properly constituted, becomes inca-
   pable of furnishing a healthy stimulus and nourish-
±  merit to all the parts of the body.  Hence the rapid
   "decline" which follows the appearance of pulmo-
   nary 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 man-
   ner in which these effects  are  produced is not so
   familiarly known.  Yet, in a practical point of view,
   a knowledge of the principle is highly important.
   Properly considered,  respiration is  in  reality  the
   completion of digestion.   The stomach may convert
   the food into chyme, the small intestines may con-
   vert the chyme into chyle, and the  absorbents may
   take up the  latter, and  duly convey it into the  cir-
   culating system; but, unless it undergo the necessary
   change in the air-cells of the lungs, it will not con-
   stitute good blood, or afford due nourishment to the
   body.  Hence it is that those among the working
   classes who are much confined in  an impure  and
   insalubrious  atmosphere, even when plentifully sup-
   plied with food, are generally thin and ill-nourished;
   and hence  those who,  along  with  good digestion,
   have small narrow chests, and very limited respira-
   tion, are  commonly found to  be constitutionally
   lean,—while those who, along with good digestion,
   have amply-developed lungs, and free and powerful
   respiration,  are  at the  same time  remarkable  for
   proportional vigour of  nutrition and stoutness of
   body.  It is on this account that in chronic pulmo- 
NERVES  OF THE  MUCOUS  COAT.    159
nary disease recovery is always  to  be  distrusted,
unless, along with the disappearance  of the promi-
nent 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 diseas-
ed  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 gen-
erally 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 pro-
vided with nerves, and has a mode of sensation pecu-
liar to itself.  Every villous point, indeed, has a ner-
vous fibre  ramified on it, to give it the  necessary
sensibility  to its own stimuli.   It is true, we are
not so 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 de-
fect.  They recognise their appropriate stimuli, and
cause the  necessary actions to follow without re-
quiring aid from the will.   But when they meet with
substances  which.ought  not to be there,  such  as
pieces of indigested food, or foreign  bodies which
have no  natural relation to their constitution, they
immediately indicate uneasiness, and excite the
muscular contractions to rid them of the offending
cause.
  To secure full and natural action in the  intestinal
canal, several principal conditions are thus neces-
sary,  failure of any of  which  may  impair  their
activity.  The first condition is well-digested chyme
and chyle;  the second, a due quantity and quality
of mucous and vascular secretions from the villous
coat; the third, full  contractile power in the muscu- 
 160        INTESTINE--DUODENUM.

 lar fibres of the intestine, and free action of the ab-
 dominal and respiratory muscles; and the last,  a
 due nervous sensibility 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 as-
 cribed,  that an appropriate  treatment may be de-
 vised.

  Such are the general structure and uses of the in-
 testinal canal; but there are modifications in its in-
 dividual 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  con-
 sidered 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, towards the right side ; it then descends
 in front of the right kidney, and there forming  a
second curve, it  proceeds again  towards 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 convexity turned towards the
right, while the pancreas or sweetbread (PP) 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 page  147, 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
PP, 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,
KK, lie one on each side of the spine; and the two
pipes UU are  the ureters, which  convey their se- 
 
 162       INTESTINE--DUODENUM.

 creted fluid to the bladder B.   The letters AA indi-
 cate the great artery (the aorta), through which the
 nutritive blood descends to supply the bowels and
 lower  parts of-the  body; and VV mark the corre-
 sponding vein (the cava),  by which the dark blood
 returns from the extremities towards the heart.   R
 is the beginning of the rectum, or straight gut, seen
 at YY in the cut on page 147.
  The  duodenum,  being  thus in the immediate
vicinity of the  spine, is fixed firmly down in its
position by the connecting 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 contin-
ual  drag upon the stomach, and disturbed its func-
tions, but likewise have been constantly altering its
own relation to the pancreatic and hepatic (or liver)
ducts, and thereby  affecting the flow of  their re-
spective fluids into its cavity, by which chylification
would have been often interrupted.
  The duodenum is much smaller in diameter than
the  stomach, but larger than the jejunum  or ileum;
and its muscular coat is also thicker.  From its size
and the importance  Of the changes effected in it, it
has been considered by some as a secondary stom-
ach, or ventriculus succenturiatus.  It is more firmly
fixed to the body than the other intestines, and does
not, like them, float loosely in the abdomen.  In its
course, until its  termination in the jejunum, it de-
scribes a  kind of C, the concavity of which looks
to the left.  From this shape it has been  separated
into three portions—the first situated horizontally
 beneath the liver; the second descending vertically
 in front of the  right kidney; and the third in the
 transverse mesocolon.
  Its mucous membrane presents a number of cir-
 cular folds,  as  shown  in the  subjoined wood-cut.
 These folds or  ruga are called vafoula connivqptes] 
DUODENUM.              163
or folding valves, and  are inherent in the nature-of
the mucous coat, and not  produced by mere folds .
of the whole thickness of the intestine, consequent- *
ly they exist even when  the latter is distended.
They are comparatively few in number in the part
of the  duodenum near the stomach, and gradually
multiply in the course downwards till they arrive at
the maximum of development at its lower end and
in the jejunum;  they again diminish in the ileum,
and disappear altogether in the  larger gut.  The
bloodvessels and nerves of the duodenum are ex-
tremely numerous, and indicate the importance of
its functions.
  The duodenum serves to receive the chyme as it
issues from the stomach, and to  prepare it  for the
farther action of the  agents of digestion.  The bil-
iary and the pancreatic juices contribute most to
chylification.   The pancreas is the  largest  of the 
 164   THE LIVER--BILE — ITS  NATURE.

salivary  glands.  A  considerable excretory duct
passes entirely through this organ, and opens into
the duodenum.  The  excretory portion of the bil-
iary system incltfdes  the proper excretory duct of
the liver, and a cul-de-sac of this  canal termed the
gall-bladder.   The  bile is generally distinguished
into cystic and hepatic.   From this peculiarity it is
legitimately enough inferred that the liver serves
the double purpose of providing a fluid indispensable
for chylification and the proper action of the bow-
els as  organs  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 costiveness 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 ani-
mal economy must be one of no small moment, if it
be justly chargeable with even a  tenth part of the
catalogue of human  ills which are laid to its ac-
count.   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 al-
ready 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 go-
ing 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 
        THE  LIVER--BILE--ITS NATURE.    165

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-blad-
der is generally more viscid, dark, and bitter than
that which proceeds directly from the liver—appa-
rently from the absorption of its more fluid parts.
It  is in this bag that gall-stones, as they are called,
are sometimes formed,  and it is  their passage
through the narrow tube in which it terminates that
causes the acute pain so often complained of in
that affection.
  From the liver the bile is conducted into the du-
odenum through a membranous tube of  about the
diameter of a quill, and which is called the biliary or
hepatic duct.  In its course a similar pipe, called the
cystic duct (from Kv<mj, kystis, a bladder), from the
gall-bladder, unites with it into one  trunk, like the
two limbs of the letter Y; and this trunk enters the
duodenum  by an orifice common to it and the pan-
creatic duct.
  In the healthy state bile is to be found only in the
duodenum, 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 artificially or by illness,
we no doubt  often bring up plenty of bile.  Some-
times 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 intes-
tinal canal, whereby it propels its contents upwards
instead  of downwards, and thus the bile is,  as  it
were, forced  up from  the duodenum  into  the stom-
ach, instead of being propelled downwards and ex- 
 166      THE PANCREAS—ITS JUICE.

 pelled 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 heal-
 thy 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,  PP, 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 bil-
 iary duct, so  that the  two fluids meet at their en-
trance, w,hich  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  apparently  modify the action of each
other. The bile being somewhat of an unctuous na-
ture,  and the pancreatic juice somewhat  alkaline,
their union forms a kind of saponaceous compound,
which is less  irritating, and more easily incorpora-
ted 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 arriving at the entrance of the  biliary
or pancreatic ducts.  From the numerous folds or
 wrinkles which line the inner surface of the duode-
 num, 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 sur-
 face is very slow.  Every particle of chyme  is thus
 allowed to receive its share of the bile and pancreat-
 ic 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 
        INTESTINE—JEJUNUM--ILEUM.     167

chyme 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 conjectures could be added, but scarcely any
facts of a very positive nature.

  The remainder of the small intestine, namely, the
jejunum (from jejunus, fasting or hungry, because it
is generally empty), and the ileum (from n\eu>, eileo, I
twist or turn about), marked  RSSSS in the cut  on
p.  147, are merely continuations  of the duodenum,
and have  precisely the same number of coats and
the same general structure.  The 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 blood-
vessels, 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  di-
minish as  we proceed downward, till, on arriving
at  the  termination of the ileum, in the  colon, or
great gut, they altogether disappear,  and the con-
tents assume the colour, smell, and appearance by
which excrement or  feculent  matter  is  character-
ized. 
168          INTESTINE--COLON.
   The division between the small and great intes-
 tines is  indicated, not only by marked differences
 in their diameter and external appearance, but also
 by an internal valve placed between them, the ob-
 ject of which is to prevent the contents of the colon
-from following a retrograde course and returning 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 colon 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 ccecum coli,  or  blind head of the
 colon, or simply the ccecum.  Its position is at T in
 the figure on p. 147, but it is hidden by the folds of
 the ileum.
   The  colon (from koiXov, 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 147; rises  upwards
 on the same side towards the liver; crosses over to
 the left side in contact with the stomach; descends
 along the left side of 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, 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 conni-
 ventes, or folds of the mucous  coat,  are no longer to 
      INTESTINE--VERMICULAR MOTION.   169

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 excremen-
titious 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 rectum, and life has been
saved in this way when nothing could be giyen by
the mouth.
  The passage of the intestinal contents from the
stomach downwards is  effected  chiefly  by the
perista'/ic or vermicular motion, that is, the succes-
sive  muscular contraction of the middle or'fleshy
coat already frequently adverted to; and  this,  in
its turn, is greatly  aided by the constant but gentle
agitation which  the whole digestive  apparatus re-
ceives during the act of breathing, and during exer-
cise 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 mp-
tion.   During  exercise  breathing  is  deeper,  and
muscular contraction  greater in power  and in ex-
tent ;  and hence the assistance afforded is also in-
creased.   Those who  take no  exercise, or who
have  the  cjiest  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 innutritious food, have been already no- 
170         INTESTINAL DIGESTION.
ticed, 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 stomach, but
in the intestines.  It is familiarly known, for exam-
ple, that when digestion is weak, fruits and  fresh
vegetable aliments 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 inter-
vals from the time of feeding, -the distinguishing
fibrous structure of vegetable  food  is observed  to
diminish 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 stom-
ach, and that it requires the aid of the  intestinal
juices for its completion.  Delabere Blaine arrives
at the same conclusion,  from considering the  pecu-
liar digestion of the horse.  In the horse,  the stom-
ach is a simple bag,  of very  moderate  size, and
yet that animal not only can drink a gallon or two
of water at a time, but can eat a much larger quan-
tity 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 towards the duodenum, where their diges-
tion is continued, but not completed till long  after
being subjected to the action of the bile and pancre-
atic 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  drowsiness,  and less incommoded  by
active exercise soon after  meals, than almost any
other animal. 
            INTESTINAL  DIGESTION.         171

  The late Baron Dupuytren had several opportuni-
ties of observing something analogous to  this  in
the human subject.  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 con-
tents  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  digestibility.   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.
   From the circumstance  of vegetable aliment con-
taining  little nourishment and much indigestible mat-
ter, it naturally happens that a larger quantity of re-
fuse 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 free-
ly, or are more open, in the former than in the lat-
ter 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  al-
most wholly absorbed.  But as  neither  the stomach
nor the bowels are adapted in structure for very
concentrated food, such articles cannot  be long used
with advantage.  Browp  and rye bread, and fruits,
are  in repute for relieying a costive  habit of body,
and their usefulness is explicable on the same prin-
ciple.  They leave a large residue to be thrown
out of the system, and this residue forms the natural 
172         CONCLUDING REMARKS.
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, increasing the lubri-
cating secretion, and giving additional facility to the
propelling powers.
  In the preceding  exposition of the structure and
functions of the organs  of digestion, many  omis-
sions necessarily occur,  and  many questions of
much intrinsic interest are passed over  with very
little notice.  But a minuter survey was incompat-
ible with both the objects and the limits of the work.
My great aim was, not  to extend the  bounds of
physiology, but to turn to a useful purpose what is
already known in regard  to one of its most impor-
tant 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 touch-
ed intelligible to  the ordinary reader, and to impress
him with a just sense of their practical  value, I
shall have accomplished  the utmost I have sought
to attain. 
PART II.
THE  PRINCIPLES OF DIETETICS VIEW-
    ED IN RELATION  TO THE LAWS
               OF DIGESTION.
                   CHAPTER I.

                 TIMES OF EATING

The selection of food only one element in sound digestion.—
  Other conditions essential.—Times of eating.—No stated
  hours for eating.—Five or six hours of interval between meals
  generally sufficient.—But must vary according  to  circum-
  stances.—Habit has much influence.—Proper time for break
  fast depends on constitution, health, and mode of life.—Inter
  val required between breakfast and dinner—best time  for
  dinner—circumstances in which  lunch is proper—late din-
  ners considered—their propriety dependant on mode of life.—
  Tea and coffee  as a third meal—useful in certain circumstan
  ces.—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, tra-
ced the progress of the food through its successive
stages of preparation for becoming a constituent el-
ement of the animal frame, and examined the struc-
ture and nature of the various organs engaged in di-
gestion, I shall now endeavour to turn the exposi-
tion to account, by making it, as far as possible, sub-
servient to a closer and more rational observance
of the laws of digestion, and to a better adaptation
                       P2 
174          TIMES OF EATING.
of diet and regimen to different ages, sexes, and con-
stitutions, 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 ur-
gent importance of the subject, and  with the suc-
cess which will infallibly attend its further investi-
gation on sound physiological principles, that I con-
sider the likelihood of personal failure to be of very
secondary  importance,  when compared  with the
benefits which will accrue  to society from  the ex-
ertions of others whose labours maybe more profit-
ably directed by an acquaintance with  the  guiding
principles unfolded in these pages.
  According to the popular notions of dietetics, the
selection of the proper kind of food seems to con-
stitute the only condition required for the enjoyment
of healthy digestion.  Hence medical men are con-
stantly questioned  whether this or that article of
diet is good or bad for the stomach, while curiosity
rarely, if ever, extends  so far as to inquire whether
nature has annexed any other conditions 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 at-
tended to;  and it often  happens that  the same food
which is digested  with ease when  the  collateral
conditions are fulfilled,  will remain for hours on the
stomach unaltered when they are neglected.  Some
of these conditions, therefore, I shall now endeav-
our to point out.  And, first, of

  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 sys-
tem, and not to eat  at stated hours as a matter of
course,  whether nourishment were required or not
If we are engaged in  exercises which  induce a rapid 
     REGULARITY IN THE TIME OF MEALS.  175

expenditure of material, or if growth is going on so
rapjdly as to require unusually ample supplies,  food
ought to  be taken both  more  frequently and  in
larger quantity than when we are differently cir-
cumstanced; or, in other  words, food ought  to bear
a relation to the mode of life*aad circumstances of the
individual, and not be determined by a reference to
time alone.
  As  society  is constituted, however, there is  so
much uniformity of occupation in the different class-
es of which it is composed, and the animal economy
is otherwise so much adapted to  the performance of
periodical operations, that  stated times may with ad-
vantage be fixed for each class, and thus the benefits
of that  social and exhilarating  intercourse  which
we all see to be so conducive to healthy digestion
may be  generally obtained.  Individuals may suffer
a little from this arrangement, but the vast majority
will undoubtedly be benefited.
  Where the mode of life is regular and nearly the
same throughout a whole class, the same waste will
go on, and the same demand  for a supply of nourish-
ment  occur, throughout all  the  individuals compo-
sing it, subject only to such variations as are induced
by original differences of age and constitution.   Con-
sequently, as regards such a class, regularity in the
recurrence of their meals is not less natural  than
advantageous;  because not only are all the individ-
uals subjected to nearly  the  same exertions, but
every day is so like another, that the want will al-
ways be felt at the same hour ; and it is only when
we attempt to combine the same 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 under-
gone a change; and if not gratified it again subsides. 
 176   INTERVAL BETWEEN MEALS TO BE

 Ultimately, however, it calls with too strong a voice
 to allow of its being thus disregarded.
  Nature has accorded to man considerable latitude
 in fixing the interval within which the demands of
 appetite must be gratified, and in this provision has
 obviously had in view the infinite variety of circum-
 stances in which he may be placed in the discharge
 of his numerous duties.  As a general rule, five  or
 six  hours should elapse between one meal and an-
 other—longer if the mode of life  be indolent, shorter
 if very  active.  Digestion occupies from  three  to
 four or five hours, and the stomach requires an in-
 terval 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,
 accordingly, does not begin to show itself till  some
 time after the stomach has been empty, and if food
 be taken before it has recovered its tone, the secre-
 tion of gastric juice and the contracting of its mus-
 cular fibres are alike imperfect, and digestion con-
 sequently becomes impaired.
  The interval between each meal ought to be longer
 or shorter in proportion to  the quantity eaten, and
 to the more or  less  active habits of the individual;
 and it would be absurd to fix the same standard for
 all.   A strong labouring man, whose  system is sub-
jected 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 restricted diet may thus re-
 quire to eat every four hours, where formerly, with
 a more copious diet, once in six hours was suffi-
 cient.  Some  indeed  are  so constituted as to  re-
 ?[uire only one  or two abundant meals  in twenty-
 our hours.
  Early training exercises great power over the
 stomach as well as over the mind.  In savage life, 
       DETERMINED BY  CIRCUMSTANCES.   177

where the supplies of food are precarious, a single
meal  may be  popious  enough to serve for two or
three  days together.  The monks of La Trappe make
it a 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  before
they become reconciled to the restriction.   I once
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 observ-
ed that he scrupulously adhered to his single meal.
He had a dispensation,  however, authorizing  hi;n to
eat animal  food and use wine during his journey ;
and I  was surprised at the extent to which he avail-
ed himself of the permission, and to see him  devour
at one time  a store sufficient to last for a week in-
stead  of a day.   But, as in the case of the boa  con-
strictor in similar circumstances,  a deep lethargy
immediately succeeded, and it was not till four or
five hours afterward that his almost apoplectic fea-
tures  became again animated and expressive;  long
before his time came round, however, his renewed
appetite betrayed itself by  expressive glances to-
wards the comforts of  the breakfast-table.
   Nature, then, has fixed no particular hours for eating,
but has left  us to adapt our regimen to our respect-
ive ages,  constitutions, and modes of life.   Where
the mode of life is uniform, fixed hours may be
adopted ;  where it is irregular, we  ought to be gui-
ded by the real wants of the system as indicated by
appetite.
  According to this principle, meals ought to be
early or late in proportion to the habits of the  indi-
vidual. If,  adhering to the order of nature, we
work by day and sleep by night, then early  break-
fast, early dinner, and  an  early evening meal, will
undoubtedly be the most conducive to sound diges-
tion and the enjoyment of health.  But if, against
the laws  of nature,  we rise from bed late  in the 
178
SUSCEPTIBILITY  GREATEST
forenoon, reserve our activity till late in the after-
noon, 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 are the best for our comfort  that can be devi-
sed ; and thte chief error lies in the practice of those
who, while they in other respects live in conformity
with nature, adopt the hours which are suitable for
those only who  turn night into day and day into
night.
  The proper time for taking breakfast depends a
good  deal on the individual constitution and mode
of life.  Those who eat supper ought not to break-
fast till one or two hours at least after rising;  but
persons who dine late and eat nothing afterward
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 exercise or serious thinking  be-
fore breakfast.  Experience is the only sure guide
in such cases, but, as a general rule, breakfast about
half an hour or an  hour after rising will be  found
most beneficial;  and those who rise very early will
do well to follow the French custom  of taking a
small 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 di-
gestive functions by studying for hours in the morn-
ing, regardless of the craving of the system for nour-
ishment and support.
  If exposure of any kind  is  to be incurred in  the
morning, whether to the weather or to the causes
of disease, it becomes a matter of much importance
that  breakfast should be  taken previously.  It is
well known that the system is more susceptible of
infection, and of the influence of cold, miasma,  and
other morbid causes, in the morning.before eating
than at any other time ; and hence it has become a 
BEFORE  BREAKFAST.          179
point of duty with all naval and military command-
ers, especially in bad climates, always to give their
men breakfast before  exposing them to morning
dews or other noxious influences.  Sir George Bal-
lingall 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 nearly so successful as an
early breakfast of warm coffee.  In  aguish  coun-
tries, also, experience has  shown that the propor-
tion of sick among  those who are exposed to the
open air before getting any thing to eat, is infinitely
greater than among those who have been fortified
by  a comfortable breakfast.   Where there  is any
delicacy  of  constitution, the risk is of course in-
creased.
  The  cause of this  susceptibility in the morning is
not difficult  to be discovered.  Not  only have the
stomach, duodenum, and upper intestine been en-
tirely empty for several hours, but the  absorbents
and other parts engaged in the function of alimenta-
tion have likewise  been in a state of repose.  A
considerable exhalation  from the skin and lungs has
at the  same time been going on; and  this,  taken
along with the deposition, whicli there is reason to
believe takes place  more actively during sleep, of
new particles to the existing organization, necessa-
rily reduces the quantity and quality of the circu-
lating fluids, and  gives  rise to a certain degree of
debility, which is  favourable to the. action of any
morbid cause, and which can be removed only by
a supply of  that nourishment of which the  system
stands so much in need, and for which the digestive
organs are  so vigorously  prepared.  The loss of
fluids during the night by insensible perspiration is
said by Nanctorius to be twice as much as when
awake.*   This, and  the loss by pulmonary exhala-
* Paris on Diet, p. 192. 
180
DELICATE  PERSONS
tion, cause a corresponding demand for fluids in the
morning, and hence the reason why our first daily
meal  is almost  universally of a more fluid and less
substantia] description than any of the subsequent
ones ; while our active exertion and loss of solids
during the day create  a proportionate demand for a
more  substantial remst in the afternoon.
  The function of absorption is  thus at its highest
pitch  of activity in the morning;  and  if the  body
be exposed to mi asm a 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 infec-
tion and other poisonous influences when the stom-
ach is empty.
  So  rapid is absorption  from the stomach in  the
morning, that I have repeatedly seen nine tumbler?.
of a saline mineral water  taken at  eight o'clock,
and a very hearty breakfast finished within half an
hour  after the water was  drunk !   When in  bad
health three years ago, I observed almost equal ex-
pedition in my  own person.  I  took half a pint of
ass's  milk at seven o'clock, and in consequence of
coughing violently, was frequently seized with vom-
iting and retching within twenty minutes after ta-
king it; but only twice or thrice  was any portion
of the milk perceptible, although the stomach was
entirely emptied.   This was even more remarkable
than the other  case, inasmuch  as milk undergoes
digestion, which water does not.   In allusion to this
rapidity of absorption,  Sir Francis Head, in speaking
of the quantity  of the  chalybeate waters swallowed
of a morning at the Brunnens  of Nassau, humor-
ously remarks,  that "  one would think that this del-
uge of cold water would leave little room for tea
and sugar ; but, miraculous as it may sound, by the
.time I got to my ' Hif there was  as much  stowage in 
SHOULD  BREAKFAST  E&RLY.
181
the vessel as when she sailed ; besides this, the steel
created an appetite which it was very difficult to
govern."*
  In setting out early to travel, a light breakfast be-
fore  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 im-
punity,, if not benefit, and I have often done so my-
self ; but experience ultimately taught me that I be-
came sooner exhausted on continuing the exertion
through the day, than when I began by eating a lit-
tle.  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 till nine, or frequently  half past nine.
Not  being  then aware of the principle under  dis-
cussion, 1 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 workpeople passing along paid their
respects at a small  shop, the only one then open,
where fancy rolls were soil, along with wine and
brandy, I  thought of following their example, and
trying how far a  roll would add to my comfort, and
impart  additional vigour to  the system.   I soon
found great reason to be pleased with the expedi-
ent,  and discovered that I was  not only less ex-
hausted 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 1 have acted on the principle now
inculcated, and with marked benefit.   I was  then
astonished  at the regularity with  which the Parisian
workmen  seemed to take their  morning dose, or
petit verre of brandy, on their way to their labours,

      * Bubbles from the  Brunnensof Nassau, p. 46.    ^
* 
 182 EXPOSURE HURTFUL BEFORE BREAKFAST.

apparently for the very  purpose of getting thai
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 early in the morn-
ing, 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 towards morn-
ing.   When reduced in strength by pulmonary com-
plaints, I  often  passed the night in comparative
comfort,  sure to awake about  five  or six o'clock
with a feeling of chill and absence of animal heat,
which I could not dissipate till after receiving suste-
nance.
  From these facts, the general inference  is  clearly
warranted, that delicate persons ought to have some
kind of food soon after  rising, and that even those
who are  healthy will  act wisely in  not  exposing
themselves  unnecessarily to fatigue, infection, or
other morbid causes, without having previously sup-
plied the wants of  the system, either partially by a
cup of coffee or tea, or entirely by a regular break-
fast.  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 bedside of
the patient,  than to one who first  takes the precau-
tion 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 even in our
own climate.*
   In boarding-schools for the young and growing,
 who require plenty of sustenance, and   are  often
 obliged to rise early, an early breakfast is  an almost
* See the Principles of Physiology, &c, chap. lii. 
BEST  TIME  FOR  DINNER.
183
indispensable condition of health.  On  the Conti-
nent, in similar establishments, 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 constitu-
tions 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 which is
most likely to he  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, di-
gestion goes on  briskly, so  that  appetite  revives
within a shorter time than after the more substan-
tial dinner.   Accordingly, in all nations and classes
of society not perverted from the course of nature
a longer interval  than five hours rarely  elapses be-
tween breakfast and  dinner.   Our forefathers dined
at noon, as our sailors continue  to do at the present
day;  and 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 common dinner-
hour, nine being  that of breakfast.  The universal-
ity of a mid-day  meal among those who rise early,
is itself a strong presumption in favour of its pro-
priety, and of its being in harmony with the laws
of the animal economy.
  To prevent business from interfering unduly with
digestion, 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, the
same practice is or lately was prevalent.  The mem-
bers 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 
1S4       BEST TIME FOR DINNER.
appetite is keen enough to induce them to eat with
zest all that nature requires, while it wants the re-
sistless force which is  given by  a fast of eight or
rtine hours.  There  is  consequently slower masti-
cation, 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 af-
fections 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 pa-
rent 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.
  In enterprising commercial communities—in Lon-
don and  Liverpool  for example—it  is a common
practice to  hasten away  to the counting-room im-
mediately 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 be-
come 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  is obtained, and a feeling of comfort  per-
vades the frame;  but nothing can be more errone-
ous than to regard this  as a proof of the indulgence
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.
4 
BEST TIME FOR DINNER.
185
  The evils attendant on this course of life are not
unfrequently aggravated by the preposterous means
resorted to  for  their prevention.   Having some
vague notion that exercise 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' con-
finement to the counting-house, proceed  to take a
walk of four or five miles before going home to din-
ner, and thus utterly throw away the  little strength
that was left to the in,  and are filled with disappoint-
ment  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 thejiorrors of dyspepsy and melancholy by fol-
lowing this  plan,  lie 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 the same  error is  often com-
mitted from the desire which is felt to have all the
lessons over before allowing  any play.
  As  a general rule, then, not more than five hours
ought to intervene between  breakfast and dinner.
If the mode 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 convales-
cence from  illness), the interval may with propriety
be shortened ; whereas, if the mode of life be sed-
entary, and  unattended with much activity of nutri-
tion, the interval may be considerably protracted
without inconvenience.   Much, also,  ought to  de-

  *  Respecting the proper regulation of exercise, see The
Principles of Physiology, chap. iv.
                      Q2 
186       BEST  TIME FOR DINNER.

pend on the natural rapidity or slowness of diges-
tion.  In some constitutions, chylification goes on
so slowly that the individual can  pass with ease
eight or ten hours without food;  whereas, in  oth-
ers, it is so rapid that a fresh supply becomes neces-
sary in half the time.  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 in-
terval,  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'them-
selves  entitled to the enjoyment  of a  second and
more substantial dinner later in the day.
  Invalids,  dyspeptics, and all who, possessing vig-
orous digestion, wish to  retain it, will  do well to
follow  the intentions of nature, and observe the in-
tervals which she  has appointed.  Those who disre-
gard them, and still digest without difficulty, have
reason to be grateful to Providence ; but they may
rest assured that  they will longer enjoy their privi-
lege, and better evince their gratitude, by submit-
ting their conduct to the ordinary laws of the ani-
mal economy, than by presuming too much on their
supposed exemption from the salutary restraints of
reason and experience.
  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 experience, and which  ought to be
adhered to  by all  whose occupations will admit of 
BEST  TIME FOR  DINNER.       187
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 find it impossible to
dine till much later in the day.  The question then
comes to be—As we cannot follow  the system laid
down by nature, what is the next best to be done!
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 meal at the natural time, about one or
two o'clock, and reserve our appetite chiefly for the
substantial meal which we have leisure to digest 1
  The principle  in virtue of which  digestion is in-
terrupted by bodily or mental labour occurring after
a full meal, having  been already sufficiently explain-
ed,  it needs scarcely be added, that the  second is
the better plan ; and moreover, that by leaving the
Btomach too long empty, we risk impairing its func-
tions and weakening the system.
  When dinner  cannot be taken earlier than seven
or eight hours after breakfast, most people will find
it advantageous to partake of some slight refresh-
ment in the meantime—enough to blunt the keen-
ness  of appetite,  but  not entirely  to destroy it.
When the individual is exposed to much bodily ex-
ertion 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  sed-
entary and the constitution formed, a bit of bread or
biscuit  and a glass of water will be far  more  ser-
viceable.   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 necessities as if digestion
were meant merely as an appendage  to taste; and
think themselves entitled  to complain of their de-
fective appetites, and the great discomfort which at-
tends the subsequent ingestion of a heavy dinner. 
188        BEST  TIME  FOR  DINNER.
 To relieve the weakness, arising not from exhaus-
 tion, 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
 arrangements over those of  man is so far acknowl-
 edged, 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 mani-
 fold advantages to the young, although, as regards
 fheir moral training, these would be greatly increas-
 ed were  they to associate at meals with their  pa-
 rents, instead of being left entirely to the company
 and management of servants.
  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 morn-
 ing, the present fashion of dining at seven or eight
 o'clock becomes much more rational than is  com-
 monly 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 ejeven, 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 ri-
 ses at twelve or one  o'clock, breakfasts at  two, and
goes to bed  at three  in the morning.  The interval
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
 ttle more than enough.  The error lies, not in  the
 ours chosen for meals, but  in the utter perversion
 of the whole system of living, by which  night is
 converted into day, and the business of life is post-
 poned  five or six hours beyond the time appointed
 by the Creator for its performance.   So far from
 the late dinner being  hurtful  in such circumstances,
 it is only the stimulus and support which it affords
« 
           BEST  TIME  FOR  DINNER.       189

that enables 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 na-
ture by which its present arrangements are charac-
terized, and no one is more willing to contribute all
that is within his power to reform them, than the
writer of these pages; but let the whole system be
amended, and do not limit the reform  simply to al-
tering the hour of dinner, while the conditions which
have led to  the existing arrangement are left un-
changed.
  In the country,  even among the higher classes, a
greater approximation to the order of  nature is ob-
servable 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 appetite becomes
keener, and digestion more vigorous; and, as a ne-
cessary result, meals are taken an hour or two ear-
lier.  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
command two hours of relaxation, the best plan, un-
questionably, is to dine about five or six hours after
breakfast.  But if this be impossible, and  active ex-
ertion 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 din-
ner not only till  business is over, but till half an
hour or an hour's repose has allowed  its  attendant
excitement 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 quar-
ter  of an hour preceding the announcement  of 
190        BEST TIME FOF  DINNER.
" 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 la-
bour with  continued impunity.  On this account,
actors, for example, w hose vocation requires exer-
tion 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 in-
tently engiged in business, are very apt to damage
themselves by neglecting relaxation  at and after
meals.
  The time for dinner ought, then, to  vary accord-
ing to the  constitution, occupations, and mode of
life of the individual;  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 scru-
pulous 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  and lively circulation
by the regular exercise of the various' functions of
mind and body in a  free and pure atmosphere, eat-
ing moderately, and enjoying 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  under-
stood, however, that we shall not exceed in quan-
tity 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 
USES  OF TEA AND COFFEE.       191
 evening.   Custom  has already  decided  the  point,
 and experience has shown  that, taken in  modera-
 tion, they rather promote than impede digestion.
 When the dinner is early—say at one, two, or three
 o'clock—a light meal of tea and bread in the even-
 ing is very suitable, as it saves the necessity of eat-
 ing a heavier supper.   If the individual be accus-
 tomed to  much active exertion in the afternoon, so
 f.s to cause considerable waste  in the system, and
 especially if he be young, a small addition of ani-
 nril 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 incurred after it,
 tea  or  coffee ought to be used more as a diluent
 than as a meal.
  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 certainly increases the feel-
 ing of comfort for the time.   Like  all other stimu-
 lants, however, its  use is attended with  the  disad-
 vantage of exhausting the sensibility of the part on
 which it acts, and inducing weakness.  This incon-
 venience 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 ungrudgingly, than taught to
 depend upon  assistance from without;  and, there-
 fore, sue 11  assistance ought  to be reserved for the
 relief of occasional exhaustion, instead of being re-
 sorted to as a regular indulgence.   The French par-
 take 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 way to obviate this  ne-
 cessity is  obviously to  eat a  more simple and more
 moderate meal.
  A  great deal has been said and written about  the
properties of tea and coffee as articles of diet.  At 
192    PROPRIETY  OF A  THIRD  MEAL.

present, however, we have to do with them only as
elements of a third meal, and must reserve the dis-
cussion of the other branch of the subject to a
future opportunity.
  In determining whether a third meal  ought to be
taken, either as tea or as supper, the general prin-
ciple already laid down will be very useful.  If din-
ner be sufficiently early to admit of digestion being
completed, and the stomach 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 bedtime to admit
of digestion being finished and the appetite renew-
ed, 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  afternoon,
comes home in the evening with a genuine and un-
deniable appetite, has a legitimate right to an  addi-
tional 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 con-
tinued 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 three 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 either food or wine, or
both.   Even in his case, six hours  may thus inter-
vene between dinner and supper; and we know
that, on an average, digestion is finished in four or
five hours.  The chief difference between him and
the farmer is, that the farmer reaps  health and
sound digestion from adhering in his hours to the
institutions ofthe Creator, and that the man of fash- 
      PROPRIETY  OF SUPPER CONSIDERED.   193

ion impairs his constitution  and  enfeebles his di-
gestion—less by the improper intervals at which he
eats, than by his wide departure from the order of
nature in the hours which he observes.
  If, iH adopting the precepts of  ultra-temperance,
we dine early, live actively, and go to bedAvith the
stomach entirely  empty, we may sleep,  but  our
dreams will scarcely be more pleasant,*ir our sleep
iiore tranquil, than if the stomach were overloaded.
1 gnawing sense of vacuity is felt in such circum-
stances, which is  apt to induce  restlessness,  and
nervous impatience and irritability.  I have repeat-
edly seen these  unpleasant  symptoms dispelled,
and sound sleep obtained, by  no  other prescription
than a cupful of arrow-root an hour or two before
bedtime.
   Except in early life,  and in the  case of those
who lead a very laborious existence, and  observe
very early hours,  supper as a fourth meal is alto-
gether superfluous, at least where any thing is eaten
at tea.  In youth,  waste, growth, and nutrition are
so active, that a moderate supper is often indispen-
sable, 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 be-
fore gbing to bed.  If dinner be taken early, and
tea be used in the afternoon, not as a meal, but
merely as a diluent, a li6"ht  supper will  be  very
proper.
   In short, the grand rule in fixing the number and
periods 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 ; ana, as an approximative guide, to bear
in  mind  that, under ordinary circumstances of ac-
tivity and health, three, four, or five hours are re-
quired 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.
                        R 
194        PRINCIPLES  ON  WHICH
If the meal be temperate and the mode of life natu-
ral, digestion will  be completed in from three to
four hours, and one  hour of rest will serve to re-
store its tone ; but if the quantity of food be great,
or the general habits be those of indolence, .diges-
tion 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 nature to pretend, as many writers  have
done, to lay down rules which shall apply to every
individual  and to every variety  of circumstances.
As  already mentioned, rules applicable  to classes
may be prescribed, because there is a considerable
similarity in the circumstances of all the individuals
comprehended in it; but even there numerous ex-
ceptions 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 obser-
vance of a very strict order in diet; but, to fit us
for the ever-varying circumstances in which we are
placed, has wisely and benevolently allowed us con-
siderable latitude, and made appetite to vary in the
extent and earnestness of its demands in  proportion
to the waste to which we are  subjected 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 circum-
stances under which I have at various times  been
placed, I have repeatedly, even as an in valid, made
sudden changes in the hours of eating, with no fur-
ther injury than temporary discomfort;  but then I
always adhered to  the general principles above in-
sisted on.  It was by some of these experiments
that my attention was first drawn to the great influ-
ence of the  accessary conditions  in retarding or
promoting digestion.  At one time, on altering my 
      MEALS OUGHT  TO BE  DETERMINED.  195

place of residence from Aix to Marseilles, I changed
at once from breakfasting at  eight o'clock, dining
at two, and taking tea in the evening, to breakfast-
ing at eleven, and dining at six.  For the first few
days I  felt uncomfortable in waiting so  long in the
morning ;  but  by following the plan of taking  a
small cup of coffee and a crust of bread soon after
rising,  and attempting no active bodily exertion
till after breakfast, every feeling of inconvenience
ceased, and the system adapted  itself to the change
as completely  as if it had never been accustomed
to any thing else.  Three  months afterward I em-
barked on the Mediterranean, and again 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 recourse to a biscuit, or
some dried fruit, early  in the morning, 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 even-
ing : if to-morrow it was postponed till eight o'clock,
which  sometimes happened, the refreshment came
in the forenoon, and a moderate 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 upon 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 man-
ifested themselves in the form of appetite, and the
requisite intervals were observed.   If a substantial
breakfast was taken at eight o'clock, then a corre- 
196
TIME OF  MEALS.
sponding interval elapsed  before another meal fol-
lowed at one or two.  If, again, the morning allow-
ance 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 it came at six or seven
o'clock, a refreshment preceded  and nothing fol-
lowed it, and the result was comfort  and  sound di-
gestion.  If, however, we yield unguardedly to the
impulse of appetite 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
fake 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 ex-
tent by those who live differently, and convert night
into day,—it would be not less  hurtful than absurd
to prescribe the same hours for meals to all, what-
ever  their  hours  of  activity, and whatever their
modes of life ; and I cannot help-thinking, that it is
the preposterous  attempt  to generalize  too much,
which, losing sight of true principle and the modifi-
cations which it requires in  individual cases, has
brought dietetic precepts into disrepute, and led to
the belief that the rules laid down  are merely arbi-
trary assumptions, resting on no solid foundations 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 fatigue and stomachic discomfort, in-
duced by ignorant infringement of the laws of diges- 
      ON  THE PROPER QUANTITY OF FOOD.   197
                                           i
tion, than I ever afterward did, even from more con-
tinued exertion when travelling as an invalid under
a better regulated system of diet.  I did not, in ei-
ther 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 ful-
ly satisfied, under  the notion that, in  travelling,  a
full diet is necessary to enable one to withstand the
fatigue ; and that, as an invalid, 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 refresh-
ment, to  prevent the  stomach becoming exhausted
from too  long a fast.   Following the dictates of ex-
perience, I have long adhered to the latter plan, and
am convinced that few who have tried both will long
prefer the former.
                  CHAPTER II.      4

        ON THE PROPER QUANTITY OF FOOD.

Quantity to be proportioned to the wants of the system.—Appe
  tite indicates these—Cautions in trusting to appetite.—Gen-
  eral 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 dis-
  ease from excess in servant-girls from the country, dressma-
  kers, &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 to determine the  quantity  which ought to be
eaten.
                       R2 
 198    TOO MUCH FOOD IS USUALLY TAKEN.

   To ensure easy digestion  and sound health, the
 quantity 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 individual's constitu-
 tion and circumstances, and not by attempting to
 lay down any standard as admitting of universal ap-
 plication.
   We  have  seen  that, where  waste is  great and
 growth active, an abundant supply of food is requi-
 red, and that, in 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 following  its dic-
 tates, 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 gratifi-
 cation  of taste, or the yearning of a vacant mind,
 with the natural craving of unsatisfied want. Dr.
 Beaumont's remarks on this subject are character-
 ized by so much soundness of judgment, that no apol-
 ogy can be required for soliciting the attention of
 the reader to the following 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 pro-
 fession, 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 who1 are not
otherwise predisposed to the complaint, frequently
induce  a diseased state of the digestive organs by
too free indulgence of the appetite.  Of this fact,
the medical profession are, generally, not sufficient-
ly aware.   Those who lead sedentary  lives, and
whose  circumstances will permit of what is called
 free living, are  peculiarly obnoxious to these com- 
    INDICATION  OF SUFFICIENCY OF FOOD.   199

plaints.  By paying particular attention to their sen-
sations during the ingestion of their  meals,  these
complaints may he avoided.  There appears to be a
sense  of  perfect intelligence  conveyed from the
stomach to the encephalic centre, which, in health,
invariably dictates what quantity of aliment (respond-
ing to  the sense of hunger and its due satisfaction)
is  naturally required for  the purposes of life ;  and
which, if  noticed and properly attended to, would
prove the most salutary monitor of health, and ef-
fectual preventive of disease.   It is not the  sense
of satiety, for this is beyond the point of healthful in-
dulii'uiee, and is nature's  earliest  indication  of an
abuse and overburden of her powers to  replenish the
system.  It  occurs immediately  previous  to this,
and may be known by the pleasurable  sensations 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 feeling enough—the  latter
too much.   The first is produced by the  timely re-
ception into the stomach of proper aliment, in exact
proportion to the requirements of nature, for the
perfect digestion of which a definite quantity of gas-
tric juice is  furnished by the  proper gastric appa-
ratus.  But to effect this  most agreeable of all sen-
sations and conditions—the real Elysian  satisfaction
of the reasonable epicure—timely attention must be
paid to the preliminary processes, such 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  imperfectly  masticated, too much  is re-
ceived 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 m
its proper vessels or in a state of preparation in the 
 200  QUANTITY OF FOOD TO BE PROPORTIONED

 circulating fluids, is believed to be in exact propor-
 tion to the  proper quantity of aliment required for
 the due supply of the system.  If a more than ordi-
 nary quantity of food be taken, a part of it will re-
 main undissolved in the stomach, and produce  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."*
  If the purposes for which eating is necessary be
 kept in mind, the keen appetite and vigorous diges-
 tion observable in growing youths, and in those who
 undergo much active exercise in the open air—and
 the weaker  appetite and feebler digestion observed
 during the middle period of life, especially in per-
 sons of sedentary habits—will appear to be in strict
 harmony with the wants of the system in the re-
 spective 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  haste  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

         * Beaumont's Observations, &c, p. 63. 
       TO AGE, SEX, AND MODE OF  LIFE.    201

Bubbles from the  Bruunens of Nassau,  by  an Old
Man,  expresses  his astonishment at  the  "enor-
mous quantity of provisions" which the  invalids and
sojourners  at  these watering-places "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  see any other animal
overpowering himself at mid-day with such a mix-
ture and superabundance  of food" (p.  71).  In
another page he returns to the subject, and quaintly
enough remarks,  " that almost  every  malady to
which  the human  frame  is  subject is, either by
high-ways or by-ways, connected with the stom-
ach ; and I must  own, 1 never  saw  a  fashionable
physician mysteriously counting  the  pulse of a
plethoric patient, or  with a silver  spoon on 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 savage nations which live ac-
tively and temperately have only one  great disorder
—death.   The human frame was not created imper-
fect—it is we ourselves who have made it so ; there
exists no donkey in creation  so overladen  as our stom-
achs ; 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 brun-
nen" (p. 91-2).
  Our supposed " Old Man" is bv no means singular 
202
INTEMPERANCE IN EATING
in his opinions.  The celebrated Roman physician
Baglivi, who,  from practising extensively among
Catholics, had ample opportunities of observation,
mentions that in Italy an unusually large proportion
of the sick recovered during Lent, in consequence
of the lower diet which is then observed as part of
the religious duties.  This is a striking fa£t, and
gives unequivocal proof, not only in favour of tem-
perance, but in evidence of the assertion that excess
in quantity is a prevailing error in society.
  Professor Caldwell, of Transylvania University,
Kentucky, in one 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 Ameri-
can consumes  as much food as two Highlanders or
two Swiss, although the latter are among the stout-
est of the race.  " Intemperate  eating," says he,
" is perhaps the most universal  fault we  commit.
We are  all guilty of it, not occasionally, but habitu-
ally, 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.common
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 ex-
cess and suffer by  the practice."  How, indeed, he
afterward exclaims, can  the  case be  otherwise,
while children and youth are regularly taught, hired,
bribed,  or tempted, "to  overeat themselves from
their birth!  Do you ask  me for evidence in proof
of this charge 1 Go to our dining-rooms, nurseries,
fruit-shops, confectionaries, and pleasure-gardens—
go even to sick-rooms—and you will find it in abun-
dance.  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  mess  often 
             A PREVAILING ERROR.         203

 onsists  of all sorts of eatable materials that can
be  collected and'crowded  together; and  its only
measure is the endurance of appetite and the capa-
city 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 eating-
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 them-
selves in every country  I have visited, where pro-
visions are abundant and cheap."*
  This is a strongly-drawn picture, but, with a mod-
ification 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, essen-
tially the same ; and, so  far as my observation 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 ex-
tent.  This is owing partly to our more advanced
civilization, and partly to the  greater  difficulty of
procuring the means of  excess ; and if I have re-
sorted to (leriuany and  the United States  for the
most striking illustrations of the principle,  it is not
from want' of examples  at  home, but because we
are so much more alive: to the errors of our neigh-
hours 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

  *  Transylvania Journal of Medicine for September, 1832, p.
313.  See also Dr. Caldwell's  excellent Thoughts on Physical
Education, and the True Mode of Improving the Condition of
Man; reprinted for A. and C. Black, Edinburgh, 1836. 
 204   ABSURDITY  OF CORNARo's SYSTEM.

 constantly exclaiming against the eating propensi-
 ties of their patients, and inculcating the practice
 of temperance.  One of the most eminent physi-
 cians of  the present day says :  " I believe that ev-
 ery stomach, not actually impaired by organic dis-
 ease, will perform its functions if it receive reason-
 able 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 di-
 gesting at all.   In the regulation of diet, much cer-
 tainly is to be 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 quan-
 tity ; and I am  even disposed to say, that the dys-
peptic 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 is obviously borne out by Dr. Beau-
mont's observation of the power of digestion being
limited by the  amount of gastric juice  which the
 stomach  is capable  of providing—an amount vary-
ing with the wants of the system, and consequently
with the  mode of 'life.
  Cornaro, Cheyne, .and others^ have most absurd-
ly attempted  to determine a standard quantity of
food for all mankind,  and have fixed it at the low-
est  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 un-

 * Abercrombie on Diseases of the Stomach, ice, 1st ed., p. 72, 
       FOOD PROPORTIONED TO ACTIVITY.   205

natural for any one to adhere to the same  invaria-
ble proportion.
  Mixtures of different  kinds of food are strongly
condemned  by almost  all  writers on dietetics,  as
injurious to digestion.   So  far, however, as my ob-
servation goes, they produce mischief much more
by the inducement to excess in quantity which variety
affords, than by the mere mixture  of different sub-
stances.   In a healthy stomach, indigestion is rare-
ly if ever 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  tempta-
tion to exceed in quantity than  where  several are
tried.
  The first intimations  of satisfied appetite are un-
questionably the best warning we can  have when
to stop eating.   If we do not go beyond this point,
the subsequent sensations  are pleasurable  and in-
vigorating, and, after a brief interval, we are per-
fectly disposed to return to active exertion.   But,
if we eat more than enough, fulness and oppression
are almost immediately experienced, and a consid-
erable time must elapse before either mind  or body
can effectually resume its activity.
  Where, either 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 propor'ion our meals to the
amount of the preceding exercise.   When this has
been active and in the open air, and waste has con-
sequently 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 quan-
tity of food daily, whatever our mode of life and
bodily exertion may be; and yet nothing is  more 
206
ADAPTATION OF DIET
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 exer-
tion.  Many females of the higher  and middle class-
es, who scarcely ever  stir out of doors except to
church, nevertheless make as hearty meals twice or
thrice a day as if they were undergoing pretty se-
vere exertion; but they sooner or later reap their
reward in bad digestion and annoying nervous dis-
orders.
  In towns we often observe the bad effects of over-
feeding in young female servants recently arrived
from the country.  From being accustomed to con-
stant exercise in the open air, and  to the compar-
atively  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 to a rich and stimulating
diet.  Appetite,  still keen, is freely indulged ; but
waste being diminished, while nutrition  is increas-
ed, fulness is speedily induced, followed in its turn
by inflammatory disease or fever,  which  sometimes
cuts short life,  where, with  better management,
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 ei-
ther to receive or to concoct the  same quantity of
aliment as before, and the patient  then escapes with
the minor evils of protracted dyspepsy or indiges-
tion.
  The operation of the same principle is still more
conspicuous in girls sent from the country to the
work-rooms of fashionable milliners and dressma-
kers in  the larger towns.  Transferred at once from
activity in the  open  air  to  confinement all day,
and often to a late  hour at  night,  at a  sedentary 
TO  CIRCUMSTANCES.
207
occupation, where there is scarcely even the means
of changing their position, and much less of enjoying
active muscular exercise, and where, consequently,
there is little waste, the digestive powers speedily
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 thank-
ful if she does not become the victim of confirmed
bad health.  In  establishments 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 producing 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 further illustrated in the case of individuals
changing from an agricultural  or other employment
carried on in the open air in the country,  and involv-
ing no very great bodily labour,  to  one of a me-
chanical kind carried on in an impure atmosphere in
a city, and requiring a severe and continued muscular
exertion.  It is a matter of experience, for example,
that the stout young men from the country,  who are
generally selected as apprentices for the laborious
occupation of letter-press printing, almost uniformly
break down during  the first ten or twelve months;
and it is only after some  years' training that  they
are  able to withstand  the fatigue.   The  vitiated
atmosphere in which they work has some  share in
« 
208       EVILS OF INTEMPERANCE.

producing this  result; but  the chief cause is, un-
doubtedly, the inadequacy of their ordinary diet to
repair the great expenditure of muscular energy to
which they are habitually subjected, and for which
they have  not  been previously prepared.  In the
office where this volume is printed, four strong and
healthy lads were engaged last summer  as press-
men, and put to work along with an equal number
of experienced men.  Already  (February) every
one of the  former has 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 has felt any incon-
venience from his exertions.  This very instructive
fact is also deserving of attention, as corroborating
what I have elsewhere said in regard to the necessity
of proper management during the period of  transition
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
unnaturally sought to relieve  the exhaustion under
which they suffered by the stimulus of  spirituous
and other intoxicating liquors, instead of  seeking it
—where only it can be effectually 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 knowl-
edge is already leading to the prevalence of more
rational ideas, and to the consequent formation of
better habits.

     * Principles of Physiology, &c, chaps, vii. and x. 
        ERRORS  OF DIET IN  INFANCY.     209

  There is no period of life during which it is of
greater importance to follow the intentions of nature
in the regulation  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 completing their
first  or second  year;  but when we consider  the
defective education, and entire ignorance of the hu-
man economy, not only of the nurses and servants,
to whose care the young 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 inquired  into
the nature  and wants of the newly-born infant, or
knows on what principles its treatment  ought to be
directed;  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 extensive, will agree with me in opinion, that
nearly one half of the  deaths occurring during the
first  two years of existence are ascribable to misman-
agement and to errors in diet.   At birth,  the stomach
is feeble,  and as yet  unaccustomed to food.   Its
cravings are consequently easily satisfied, and fre-
quently renewed.   A healthy infant seeks the breast
with avidity, but sucks a little at a time.  It leaves
an interval for thoroughly digesting the  little which
it has swallowed; after which its appetite revives,
and a fresh supply is demanded hi a language which
no mother can misinterpret. During the first months,
appetite ought, to be the mother's guide in offering
the breast; and if she know how to read the expres-
sion of  her infant aright, she  will want no other.
At that  early age, there ought to be no fixed time
for giving nourishment.  The  stomach cannot be
                      S 2 
210    ERRORS  OF DIET IN  INFANCY.
thus satisfied.   In one child digestion may be slow,
and  the interval be consequently too short;  in  an-
other it may be quick, and the interval too long.
But  the  active call  of the infant  is a sign which
needs never be  mistaken, and none else ought to be
listened to.
  Many mothers consider every expression  of  un-
easiness 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  prece-
ding repast.  Nothing can be more injurious than this
custom.  It overloads and oppresses the stomach,
—excites  griping and bowel-coinplaints, restless-
ness and fever,—and not unfrequently leads to fatal
diseases in the  brain.  It does  harm also by with-
drawing the mother's notice from the  real  source
of uneasiness.
  It is astonishing, indeed, with what exclusiveness
of understanding eating is regarded even by  intelli-
gent 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 dis-
composed by the loss of a toy, it is forthwith sooth-
ed 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 pep-
permint drops," or some other equally pleasant an-
tidote.   Because the mouth is open when the child
is crying, and the mouth leads  to  the stomach, pa-
rents jump to the conclusion that it is open for the
purpose of being filled, and proceed to cram it ac-
cordingly ; 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 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 
     REGULATION  OF  DIET  IN  INFANCY.  211

air, they run  the risk of suffocating the little inno-
cent when their only wish is to sooth him.  Every-
body must have  seen fits  of convulsive  cough in-
duced 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 indifference 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 distention
of its stomach. "But so far is this important 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.
  " Let  appetite, then, be  the  only rule, but  allow
it to appear, and do not attempt to provoke it.  The
breast ought not to be offered to the infant; it is for
him to seek  it.  He has little need of sucking who
takes it with indifference, or as if he were confer-
ring a favour.  He who is hungry acts very differ-
ently; all his gestures express clearly the want and
the desire; his eye follows his nurse, and  tries  to
interpret her every movement.  If he is crying, his
cries cease at her approach, and  smiles replace  his
tears.   If he is offered the  breast, he seizes it with
ardour,  and  the mother yields to a natural want."
But it is far otherwise when real appetite is want-
ing, and " it then becomes  an act of cruel perfidy to
tempt the infant by the offer of the breast.  How can
it  be'expected to resist the temptation, when the
adult, whose appetite is already satisfied at the fes-
tive board, yields to the solicitations of the host, 
212  REGULATION OF DIET  IN INFANCY.
  and gorges himself with aliments which he cannot
  digest?"*
    The same intelligent author remarks, that the low-
  er animals instinctively avoid this error, and, instead
  of offering suck too often, rather allow  themselves
  to be strongly solicited before yielding to the wishes
  of their young.  By this provident  arrangement,
  the  latter  are protected from the evils  of too fre-
  quent eating.   Many mothers imagine that milk is
  so bland a fluid that it is impossible for an infant to
  take too much of it; but the fallacy of the notion is
  exposed when we recollect  that milk is coagulated
  the  moment  it reaches the stomach, and that the
  real subject of digestion is curd—a substance not
  quite so light as milk has the appearance of being.
    The grand rule, then, during the early months of
  infancy, is to  satisfy the clearly indicated and as-
  certained wants of the child, but neither to confine
  it to reguhir  hours, nor  to offer it  food when it is
  crying solely from pain and not from hunger.  When
  the  system has become more developed,  and the
  stomach accustomed to the exercise of its functions,
  regularity  in the distribution  of its meals may be
  gradually and beneficially introduced ;  because, in
  the'animal economy, there is a natural tendency to
  periodicity, which greatly facilitates the formation
  of proper habits.           •
    From the sudden change  attending the introduc-
  tion of the infant into the world, the many new sen-
  sations which it begins  to feel, and the non-secre-
  tion of milk in the mother's breasts for  some hours
  after delivery, it seems  to have  been intended by
  nature that both parent and child should have some
  time for repose before a supply of food should be re-
>  quired by the one or furnished by the other.  But,
  through pure  ignorance and mistaken kindness,
  many nurses, imagining themselves wiser than na-

         * Londe, Elemens d'Hygiene, vol. iL, p. 161. 
       REGULATION OF DIET IN  INFANCY.   213

tare, and conceiving that the newly-born infant must
of necessity be starving after what they consider a
nine months'  fast,  hasten  to fill  its stomach with
gruel or some other food.  Not unfrequently, severe
indigestion is thus induced at the very outset, which,
in a delicate  child, may be sufficient to lay the
foundation of much suffering and  bad health.
  On the general principle that  no physical want
ever exists without the means of supplying it having
been provided by nature, we may safely infer tha£
in ordinary cases, the secretion of milk will be be-
gun  before  the infant  can  possibly require it;  and
to counteract  this arrangement is to set ourselves
up in direct opposition to the Creator, and to give
a species of food for which the stomach is not then
adapted.
  It is true that, in the artificial state of society in
which  we live, the secretion of milk is sometimes
delayed so long as to endanger the  welfare of the
child.  In such cases,  it may be  necessary to give
a few teaspoonfuls of fresh cow's milk diluted with
water, as a temporary substitute for its natural food;
but this ought to be only when the necessity is ob-
vious,  and  in very small quantity at a time, other-
wise the stomach and bowels  will  to a certainty
suffer.
  One evil result of the  ignorance of the animal econ-
omy which prevails in society, is an habitual distrust
of, or  want of faith in, the efficiency of  the laws
which  God has appointed for the regulation of the
animal functions.  We cannot rest satisfied with
discovering and yielding obedience to his designs,
but we also must do something to assist or correct
them !  At birth, for example, the stomach and bow-
els, never having been  used for the purposes of di-
gestion, contain  a quantity of mucous secretion—
meconium—which requires  to  be  removed before
they can enter upon their functions.  To effect this
object, nature has rendered the first portions of the 
214   CONSEQUENCES OF  OVER-EATING.

mother's milk purposely watery and laxative ; and,
on the part of the infant, nothing further is required
than to allow it to follow its natural instinct and
suck  it in.  Nurses, however, distrusting nature,
often hasten to administer castor oil or some other
active purgative in preference, and the result is the
excitement of irritation in the stomach and bowels,
which is not always easily subdued.   If the young
of the lower animals  were  treated  after the same
unnatural fashion, it can scarcely be  doubted that
the mortality among them also would be greatly in-
creased.
  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 univer-
sal  use of purgative medicines, with a view to  re-
move 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 with-
out the aid of laxatives.  If they are not,  the Crea-
tor 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 consti-
tuted to act without external aid, it necessarily fol-
lows that a wide departure from the  order of nature
must  have taken  place somewhere, to produce  the
inactivity 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 
      CONSEQUENCES  OF OVER-EATING.    215

taking place, or of that constantly-recurring contrac-
tion and relaxation 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 re-
pletion 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 nutritious aliments, either  digestion
must fail, the system become too full, or some arti-
ficial 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 excited
to the brink of active or inflammatory disease, a sud-
den 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 purga-
tives, 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 med-
icine.   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 con-
ditions 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
trround  us, so as to impart that gentle impulse to 
216   CONSEQUENCES OF  OVER-EATING.

the stomach and bowels which I  have already de-
scribed as necessary to their action, we shall have
no  need of laxatives to assist them.  But if we
choose to neglect his laws, and to live in bodily in-
action within doors, and thus deprive the bowels of
all natural aid, let us at least take the blame to our-
selves, 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 re-
quires, and  thus stand in need of purgatives to ena-
ble us to throw off the  load, let us at least be just,
and, instead of lamenting over a defective constitu-
tion, let us deplore the ignorance which has hitherto
blinded us to the perception of the truth, and led us
to blame a  Being whose  arrangements are so evi-
dently 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 necessary 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 hab-
its, 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 inac-
tion and confined dress of a sedate young lady, who
never walks out except at a measured pace to
school or to church, is  it really wonderful that 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  necessary 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 purpose- 
       CONSEQUENCES OF  OVER-EATING.   217

ly for our  molestation.   So many heavy charges
are continually brought against them, that they can
scarcely  ever be found in the right.  They are bla-
med for every act of mischief which cannot be clear-
ly proved against another organ ; and yet, influential
as they are in  affecting our comfort, they  are treat-
ed by us  with  very little care or ceremony.   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 them.  They are,  in. short, the
scape-goats which must bear all our  physiological
delinquencies, and save us the pain of blaming our
selves.   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 some other wehVrelished article. We
have nothing to  do with the mischief except  as
meek and resigned  sufferers.  We never  eat more
than enough. We never devour lobsters, or oysters,
or salmon, or cheese, or any thing which experi-
ence has told us  our enfeebled stomachs cannot  di-
gest !  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 delib-
erately, and with malice prepense !   The case is
hard,  no doubt,  that we  cannot  lead indolent and
slothful lives, and yet enjoy the incompatible luxury
of having the appetite of  a rustic and the digestion
of a tiger ;—but since we  are so unfortunately con-
stituted that we must act like rational  creatures or
suffer the penalty, would  it not be a wise  proceed-
ing to set a better watch on the stomach, and try to
subject it to more effectual control ?
                      T 
218        DIET IN MATURE  AGE
  In mature and middle age, after the effervescence
and boisterous activity of youth are over, still great-
er caution than before becomes requisite.  Growth
no  longer  goes on, and  nourishment  is  needed
merely to supply waste ; and accordingly the appe-
tite becomes less keen, and the power of digestion
less 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 ex-
cess for a time, but ultimately dyspepsy, or  some
form of disease dependant on indigestion, will cer-
tainly ensue.   The attempt to combine 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 op-
erate with  unrestricted freedom.
  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 cir-
cumstances in which an individual may be placed.
If every trifling change in the quantity or quality of
food  were  to be followed by mischievous conse-
quences, no one  could retain health for a single
day; and if the stomach had no power of partially
adapting 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 accus- 
      ADMITS OF CONSIDERABLE VARIETY.  219

tomed to the reception of either a larger or a smal-
ler quantity of food  than  what the necessities of
the system require.  If it  is accustomed to too
much, and  less than usual be allowed, an unpleas-
ant feeling of vacuity will arise, accompanied by a
craving for more ; but after a few days the unpleas-
ant sensation will disappear, and the feeling of sat-
isfaction  be as great as if a full  meal had been ta-
ken,  and  digestion will become  more  healthy and
vigorous; whereas,  if more food  continues to be
taken than what the system requires, merely to grat-
ify the temporary craving, ultimate bad health will
be the inevitable result.
  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 what is requisite to carry on growth and
repair the ordinary waste of the system ; and from
custom, not from want, we continue to fill it as lib-
erally after  growth  is completed and waste is di-
minished 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 the indications of appetite,  and are
not satisfied till it is  removed.   The  natural conse-
quence 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 nu-
merous evils which we daily witness  as fruits of
indigestion.
  In thus punishing us with the pangs of indigestion
as a warning to  more  reasonable conduct, Provi-
dence displays the purest  beneficence.  To place
this  in a  clear point  of view, let us suppose diges-
tion  to continue perfect, notwithstanding the daily
reception of an excess of food  into the stomach,
the result would necessarily be the regular forma-
tion  of an undue quantity of chyle ; this, in its turn,
would produce an excess of blood throughout the 
 220   INDIGESTION OFTEN  BENEFICIAL.

 whole system ; and the individual would thus exist
 with all his functions in a state of constant oppres-
 sion, and in continual  danger of the rupture of a
 bloodvessel, till,  from  mere fulness, some active
 disease would be excited, requiring the instant and
 vigorous use of the  lancet  for its  relief, or very
 probably cutting  short life.  If, then, man cannot
 restrain his appetites, and effectually subject them
 to the control of reason, another check against con-
 tinued  aberration is  required; and, fortunately for
 us, it is to be found in the refusal of the stomach to
 continue to digest much more than the quantity de-
 manded by the wants of the body.  In practical life
 we meet, in fact, with  both  results. .  There  are
 some persons constituted with such vigorous pow-
 ers of  digestion, that no quantity of food oppresses
 their stomachs.   If they eat habitually  more than
 what 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 ex-
istence, such as inflammation, apoplexy, rupture of
bloodvessels, 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 enfeebled by the over-
 exertion to which it is subjected, just as the muscles
do from excess of labour;  and the  consequence 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 nour-
 ished—and that, on the  contrary, the stoutest men
 are often those who eat comparatively little.
   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 ben-
 efit to  ourselves  it will make a great   difference
 whether we regard indigestion as  merely an acci- 
      DIET OF THE LABOURING CLAS8ES.    221

dental and capricious occurrence, unconnected with
conduct, or  as  purposely meant to warn us  from
continuing 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 de-
struction till it is no longer in our power to turn
back ; whereas, in  the latter,  we  cannot  feel  a
single pang  of indigestion without being remind-
ed 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 there-
fore  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 indispensable 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 labouring poor.  Pressed
upon all sides by the powerful competition both of
constantly improving machinery and of a  super-
abundant population, the manual labourer is  impell-
ed 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;  and when, as often happens
along with this  excess of labour, his food, from in-
adequate wages, the size  of his family, or his own
injudicious management, is defective in quantity or
                      T2 
222  RESULTS OF DEFECTIVE NUTRITION.

in quality, the consequences to his health and hap-
piness 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 gen-
eral fact, at least nine tenths  of the lower orders
suffer physically,  morally, and intellectually,  from
being over-worked and under-fed ; and yet I am con-
vinced that  the more the  subject shall be investi-
gated, 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  want
of food;  but it  is not  less certain that thousands
v-pon thousands are  annually 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.
They almost all 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 mortality of a country  may be considered  as an
accurate  indication 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 con-
firmed by every day's experience in Britain as well
as in France.  Many causes concur to produce  this
melancholy result, but among the principal is  un-
questionably the disproportion so generally existing
between toil and nutrition.  In the army, the opera-
* Smith's Philosophy of Health, Chapter IV. 
      RESULTS OF DEFECTIVE NUTRITION.  223

tion 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 successfully against  fa-
tigue and temporary privations by which the latter
are overwhelmed.  During epidemics, too, the poor,
from their impaired stamina, almost  invariably be-
come 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 con-
stitution of the labouring poor.  Their minds also are
deteriorated.   The  pressure of poverty is unfavoura-
ble to the growth of refinement and morality, and
crime  and  turbulence are  never so much to  be
dreaded as during times of scarcity and manufactu-
ring or agricultural distress.  Bodily health, satisfied
appetite, and peace  of  mind, are  great promoters
of individual morality and  public tranquillity; and
whenever these are encroached upon in any great
class  of the community, discontent  and crime are
sure to follow.  In legislation this principle is sel-
dom attended to, and laws are consequently enacted
merely for the suppression of the result, while the
source from which it springs is left  altogether un-
noticed and in the  fullest activity.
  Among the poorer classes, the children  as well
as the parents suffer much both physically and mor-
ally 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 develop- 
224   RESULTS OF DEFECTIVE  NUTRITION.

ment of the bodily organization,  a  corresponding
deficiency of mental power, and a diminished ca-
pability of  resisting  the  causes  of disease.   In
work-houses and other charitable institutions, ample
evidence of these deficiencies obtrudes  itself upon
our notice, in the weak and stunted forms and very
moderate capacities of the children.  Under an em-
poverished diet, indeed, the moral and  intellectual
capacity is deteriorated  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 pro-
vided with the care which it deserves.   Both in fami-
lies and in  boarding-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 proportion 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 perseve-
ring  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 children. 
DIFFERENT TEMPERAMENTS.      225
                  CHAPTER III.


               OF THE KINDS. OF  FOOD.

What is the proper food of man ?—Food to be adapted to consti-
  tution and circumstances.—Diet must vary with time of life.
  —Diet in infancy.—The mother's milk  the  best.—Substi-
  tutes for it —Over-feeding a prevalent error.—Causes which
  vitinte the quality of the milk.—Regimen of nurses.—Wean-
  ing.—Diet after weaning.—Too early use of animal food hurt-
  ful.—Diet of children in the higher classes too exciting—and
  produces scrofula.—Mild food best for children.—Incessant
  eating very injurious.,—Proper diet from childhood to puberty.
  —It ought to be full and nourishing, but  not stimulating.—
  Often insufficient in boarding-schools.—Diet best adapted for
  differqpit constitutions in mature age.—Regimen powerful in
  modifying the constitution, mental as well as physical.—Far-
  ther investigation required.

  The next  question which presents itself is, What
is the proper food of man ?  In answering it, we
must  begin  by  making distinctions, otherwise we
shall, in the  very outset, fall into error.
  On examining the structure of the human  body at
different  ages and in different  individuals, remark-
able differences are  observable in the relative pro-
portions  of  the  elements  or tissues of which it is
composed.   In one, the muscular system predomi-
nates, and the body is remarkable  for  a compact-
ness of fibre indicative at once  of strength and ac-
tivity.  In  another,  the  lymphatic  system  is the
most conspicuously developed,*and its features are
easily recognised by the full, soft, and rounded form,
and languid  action, which generally accompany it.
In a third, the thin and sharp outline, irregular and
vivacious activity, and great susceptibility of impres-
sions, betoken the  predominance of the  nervous 
226      FOOD SHOULD BE ADAPTED

over all the other functions; while, in a fourth, the
florid complexion, expanded chest, and general viva-
city of disposition, as clearly point out the superior
development and energy of the vascular system.
Such are the four principal constitutions, long famil-
iarly known under the names of the bilious, the lym-
phatic, the nervous, and the sanguine temperaments.
Very frequently the habit of body  indicates  a mix-
ture of two  or more  of  these temperaments, in
which case the results of course are  modified accord-
ing to the proportions in which they are combined.
  The elementary textures  being  thus differently
proportioned in different individuals, it follows that
the aliment best suited for the support and repair of
one is not always so for the others ; in other  words,
a distinct modification of diet ought to be adopted
for every marked variety of constitution, because
a direct relation  ought always to subsist between the
qualities of the food and the nature of the system which
it is intended to nourish.  Thus, the highly concen-
trated and  stimulating food which is  found  neces-
sary for the proper sustenance of the trained pugil-
ist or sportsman, whose muscular  frame is in high
development and constant exercise, would prove far
too exciting to the slender and irritable constitution
of a person whose characteristic feature is the pre-
dominant activity of the brain and  nervous system.
And, in like  manner, the generous and stimulating
diet which suffices  merely to 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 to-
wards inordinate activity.
  The necessity of adapting the diet and regimen to
the individual constitution  and mode of life  be-
comes so obvious to  reason, when  thus plainly sta-
ted, as to excite surprise that it should  ever have
been  neglected.  But, strange to say, although the
ancient writers attached much importance  to  the 
TO  THE  CONSTITUTION.        227
subject, the relation between diet and constitution,
as a practical consideration, has of late been so en-
tirely overlooked, and sound physiological principle
has been so little consulted 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  before
more can be supplied.   My own observations have
not been extensive or accurate enough  to  enable
me to lay before the reader any new or definite re-
sults ;  and I notice  the deficiency here  only be-
cause I am deeply impressed with  its importance,
and hope that others may be induced to observe for
themselves, and make known any information which
they may obtain.

„  There is no kind of alimentary substance of which
it can be said absolutely that it is always proper for
the sustenance  of man.   To be serviceable, the food
must be adapted to the age, constitution, state of health,
and mode of life of the individual, and  to the  climate
and season of the year.  The same diet which, admin-
istered to an adult, is healthful and nutritious, may
prove"irritating and injurious to a child;  and, in like
manner, the stimulating animal diet which in winter
is highly grateful to the system of a hard-working
unexcitable labourer,  may prove  utterly destruc-
tive 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.
   Among these modifying  causes, the varying state
of the body at different periods of life ought  certainly
to be considered 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 different individuals at the
same age.  In  infancy, the lymphatic and nutritive 
228
DIET IN  INFANCY.
functions greatly predominate  over the muscular;
and if the highly animalized food which suits the
latter were then freely administered, it would infal-
libly induce  disease, and fail to afford the requisite
nourishment.  In manhood, again, when muscular
activity and nutrition  are at their height, the lym-
phatic system in abeyance, and the person subjected
to laborious exertion, the mild food of infancy 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, re-
quires food of a different kind from that fitted for
either of the preceding stages.
  Even the state of the digestive organs at different
periods  of life is sufficient to indicate a correspond-
ing modification of diet to be proper for each.
In early infancy, when no teeth exist, and the mus-
cles which move the  jaws are still comparatively
small and  powerless, and  mastication is  conse-
quently 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 heal-
thy quality and in sufficient quantity, no other ought
to be substituted-in its place.  After the milk-teeth
have  made  their appearance, but not till  then, a
little admixture  may  be permitted, and gradually
and cautiously increased in proportion as dentition
advances, and the stomach becomes fitted to digest
other food.  If, however,  the  appearance of the
teeth  be  retarded by inability in the  mother  to
furnish  an adequate supply of sustenance  (which
sometimes  happens), the deficiency must be made
up either by providing a nurse of a healthy consti
tution, or by other means to be presently mentioned.
The former is  the preferable remedy ; but where a
nurse cannot be procured, and the mother's milk is
scanty,  the  child  may, after  the  third or  fourth
month,  receive at  proper intervals a  small  allow- 
THE MOTHER'S MILK THE BEST.    229
ance of cow's milk, diluted with one third of water,
and slightly sweetened.   This makes the  nearest
approach to the nature of the mother's milk, and
is therefore more suitable than any preparation of
milk and  flour or arrow-root that can be given.
Ass or goat milk answers still better.
  The  appearance, of the first teeth is  an indication
that the digestive organs  have become sufficiently
developed  to  admit  of small portions of barley-
water,  panado, a thin arrow-root, or milk and water,
being given two or three times daily in additlln to
the nourishment drawn from  the mother's breast,
if the latter be at all deficient.   Great  care must be
taken,  however, neither to exceed in  quantity, noi
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 appearance 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 according  to the wants
of the  system, an excellent preparation is made for
the process of weaning, which would  otherwise, by
its  suddenness,  be attended with serious risk to
both parent and child.
  The milk of the parent ought, in every instance,
to constftute the food of the infa.it, unless some
very urgent reason prevents the mother from suck-
ling, or renders her milk improper for the  child.
There is always a relation  between  the condition
and  constitution of  the  mother, and  the age and
constitution of the infant, which renders this proper,
and which cannot exist between the child and any 
230    OVER-FEEDING TO BE AVOIDED.
other nurse, but which exercises an important in-
fluence on its nutrition.   It is well known, for ex-
ample, that during the first few weeks, the milk is
thinner and more watery than it afterward becomes.
If, consequently, a newly-born  infant be provided
with a nurse in the third or fourth month, the natu-
ral relation between its stomach and the quality of
the milk is destroyed, and the  infant suffers from
the oppression of food being too heavy for its pow-
ers.   If, again, an infant  of five or six months old
be t^nsferred to a nurse recently delivered, the ali-
ment which it receives is too watery' for its  sup-
port, and its health in consequence gives way.
  In like manner, if the  parent be of mature  age,
her own milk, or that of a healthy nurse of a nearly
similar age, will be more  suitable to the infant than
the milk of a much younger woman; because the
constitution of the offspring always bears a relation
to that of the mother, and is adapted to the quality
of the fluid which nature has  provided for it.   I
speak, of course, only of the healthy state; for in
cases of disease, the mother may be, and often is,
the most unfit nurse that can be found for her own
child.  But as, in  such instances, the parents are
always guided in their conduct by medical  advice,
and this is  not  the place to discuss the  treatment
of disease, I need not now enlarge upon it.
  The leading error in the rearing-of the young, I
must again repeat, is over-feeding—an error serious
in itself, but which may easily be  avoided by the
parent yielding only to the indications of appetite,
and administering food slowly and in small quanti-
ties at a time.  By no other means can the colics
and bowel-complaints, and irritability of the nervous
system, so common in infancy, be  effectually pre-
vented, and strength  and healthy nutrition be se-
cured.  Nature never meant the infant stomach to
be converted into a receptacle for laxatives, carmin-
atives, antacids, spicy stimulants,* and astringents; 
MOTHER'S MILK OFTEN VITUTED.    231
 and wh n these become necessary, we  may rest
 assured that there is something faulty in  our man-
 agement, however perfect it may seem to ourselves.
 The only exception is where the child is defectively
 constituted, and then, of course, it may fail to thrive
 under the best measures which can be devised for
 its relief.
   Another cause of infantile indigestion, and which
 is too  much overlooked through ignorance of its
'importance,  is vitiation  of the quality of the milk,
 caused by imprudence,  neglect, or anxiety oji the
 part  of the  mother.  The extent to  which mis
 cause operates in inducing irritation and. suffering
 in the  child, is  not generally understood; and ac-
 cordingly, it is not unusual for mothers to  display
 as much indifference to health, regimen, and tran-
 quillity of mind during  nursing, as if the  milky se-
 cretion, and all other bodily functions, were inde
 pendent of every external and corporeal influence.
 Healthy, nourishing, and digestible milk can pro-
 ceed only  from  a healthy and  well-constituted
 parent ; and it is against nature to expect  that, if
 the mother impairs her (health and digestion by im-
 proper diet,  neglect" of exercise, impure air, or un-
 ruly passions, she can nevertheless provide a whole-
 some and uncontaminated fluid, as if she were exem-
 plary in her  observance  of all the laws of health.
   It is no new or uncertain doctrine that the quali-
 ty of the mother's milk is affected by  her  own
 health and conduct, and that, in its turn, it directly
 affects the health of the  nursling.  Even medicines
 given to the parent act  upon the child through the
 medium of the milk; and a sudden fit of  anger, or
 other violent mental emotion, has not unfrequently
 been observed  to change the quality of the fluid, sow
 much as to produce purging and gripes in the pjj^Jd.^^.
 Care and anxiety, in like manner, exerl  a most per-   >
 nicious influence, and not only diminish the quan-
 tity, but vitiate the quality of the lnilk.'Jjfyjlu
if 
,232
PROPER  DIET FOR NURSES.
      As soon, then, may we expect to see a bad tree
  .; bringing forth good fruit, as bad management good
    results ; and low must that parent be ranked in the
    scale  of moral beings,  who, knowing the  relation
    we have pointed out, can still deliberately sacrifice
    the welfare of her offspring by the improper indul-
    gence of her appetites and passions, and by culpa-
    bly neglecting the duties and restrictions demanded
    by her "own health.
      It is a common mistake to suppose that,  because
    a wpfian is nursing, she ought therefore to live very
    fully, and to add an allowance of wine, porter, or
    other fermented liquor, to her usual diet.  The only
    result of this plan is to cause an unnatural degree
    of fulness in the system, which places the nurse on
    the brink of disease, and which of itself frequently
    puts a stop to, instead of increasing, the secretion
    of the milk.  The health and usefulness of country
    nurses are often utterly ruined by their transplanta-
    tion into the families of rich and luxurious employ-
    ers.  Accustomed at home to constant bodily exer-
    tion, exposure to the air, and a moderate supply of
    the plainest food, they live in the enjoyment of the
    best  health, and  constitute  excellent  nurses.  But
    the moment they are translated from their proper
    sphere, their habits and mode of life undergo an
    unfavourable change.  Having no longer any labo-
    rious duties  to perform, or any dally exposure to
    encounter, they become plethoric and indolent; and
    as they are at the same time too well fed, the digestive
    functions become impaired,  the  system  speedily
    participates in  the  disorder,  and the milk, which
  •  was at first bland, nourishing, and plentiful, now
    becomes heating and insufficient,  and sometimes
   ■■•■even»tojas.t^ltogether.  The motive which induces
t-^Fthg motJermtake the nurse out of her proper  ele-
 *  meht is'~e|fl||rnely amiable—she is desirous to see
    that her 'intuit  is  properly  attended to ;  but  the
    methodJjBbh she takes to gratify this desire is not 
PROPER  TIME  FOR  WEANING.      233
on that account the less short-sighted and errone-
ous.   If the nurse cannot be trusted with the child
at her own home, care ought to be taken  at least
that her diet and mode*of life be changed as little
as possible from those which experience has proved
to be most conducive to her health ;  and the system
of feeding, confinement,, and  indolence usually re-
sorted to, ought to be  strictly prohibited, as fraught _
with evil to both nurse and child.
  Nature, indeed,.has saved mothers the necessity
of oppressing their stomachs by way of  providing
for the wants of their young,  and has enabled them
to give  suck without  either suffering from  exhaus-
tion or having recourse to inordinate eating.  This
is accomplished simply by the suppression of that
periodical evacuation to which all healthy women
are subject during  the greater portion of life, except
when pregnant or  nursing; and as,  in every situa-
tion, it is certainly more advantageous for  all  par-
ties to follow  out  the intentions of nature, than to
substitute any contrivance of their  own to effect a
given end, so,  in the present instance, more will be
gained by the Observance of the ordinary  laws of
health on the part of  the nurse, than by any foolish
deviation founded  on ignorance and caprice.
  The length of time during which an infant ought
to be fed at the breast is subject to  some variation.
In this country, the end of the ninth month is  usu-
ally  considered a proper time  for weaning;  but
much depends on  the condition of the mother, and
also  on that of the child. If both are in vigorous
health, if the infant has cut several of its teeth, and
been already accustomed to  be fed,  and if the sea-
son be favourable, weaning ought to be then gradu-
ally accomplished.  But if the nursling is feeble in
constitution, the teeth late  in appearing, 'and the  ^  ,
nurse has a sufficient supply of good milk, espe-  *
cially if it be  the winter season, it  will be  fawbet-
ter to prolong  the nursing for a few months* In 
234        DIET  AFTER WEANING.
 -  such a case, the single fact of the non-appearance
    of the  teeth would suffice to indicate an unfitness
    of the system for any other than the natural food
    from the maternal breast.  In  general, weaning
    takes place too early.
      Where a healthy and well-constituted nurse has
    been provided, on account of the existence of an he-
    reditary taint, such as active scrofula or cancer, in
    the parent, it is generally advantageous to defer the
    weaning beyond  the usual time.  But we must, in
    this case, be watchful not to delay it, if either the
    nurse or the child begins to suffer from its continu-
    ance.
      It would carry me  too  far from the main object
    of this work to discuss all the contingencies  against
    which it is occasionally  necessary to provide in
    the management of the young.   This, however, is
    scarcely required, seeing that medical advice is gen-
    erally resorted to at the time of their occurrence;
    p.nd the exposition of principles already given will
    enable most reflecting readers to decide for them-
    selves how far they may safely trust to their own
    lights, without delaying to seek advice from others
    till the  evil is done.
      After the child has been weaned, panado, 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 chick-
    en-broth or beef-tea,  freed from fat, and thickened
    with 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- 
DIET  OF  CHILDREN.          235
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 di-
gestive 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 pro-
duced, which impede nutrition, and lead ultimately
to the production of scrofula and  other organic
changes in the glands and bowels, and not unfre-
quently also  in the brain  and  lungs.  In these in-
stances, the child generally eats heartily, but never-
theless continues thin,  and is subject to frequent
flushing and  irregularity of the  bowels, headache,
and restlessness.  His mind partakes of  the  gen-
eral irritability of the system, and  peevish impa-
tience takes  the place of the  placid good-humour
natural to healthy childhood.  In this state, the or-
dinary diseases of infancy—measles, scarlet fever,
and hooping-cough—are often  attended with an un-
usual and dangerous degree of  constitutional dis-
turbance ; 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 er-
ror from  which they spring,  are most frequently
met with  in the middle and higher  classes of so-
ciety.  Aware that  animal substances 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 overlook-
ed, the fond  parent naturally imagines  that  the
more nutritious the food, and  the larger the quan-
tity administered, the stronger  and healthier will
the child become.  No suspicion is entertained that
strong diet may  overpower weak organs, and thus 
236           BAD  EFFECTS OF
 induce the very evils which it is  sought to avoid;
-whereas, by adapting the quality and quantity of the
 food to the condition 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 stimulating 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 Dr. Clark, in
 treating of the prevention of scrofula  and .consump-
 tion  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 con-
 tinued mismanagement  of diet; and both the public
 and the  profession are deeply indebted  to him for
 drawing attention to the extensive influence of dys-
 peptic 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 men-
 tal disorders 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.  Dr.
 Clark's  treatise, however, presents  a remarkable
 exception, and  may be referred to  as a most in-
 structive specimen of cautious and  discriminating
 medical inquiry.
   When we reflect that the object of digestion is to
 furnish materials for the growth of the body, and to
 supply the waste which  the system is  constantly
 undergoing, it must appear self-evident,  that if the
 digestive powers  be impaired by disease, by im-
 proper quantity  or  quality of food, or by any other
 cause, the result must necessarily be  the formation
 of an imperfect chyle, and consequently of imper- 
IMPROPER DIET.            237
feet blood.  The elements of the blood are derived
from the chyle, and if it be  vitiated, the blood also
must suffer: if the blood be  empoverished,  so must
necessarily be all the organs which it supplies ; and
if the body be thus debilitated, can any wonder be
felt that it should no  longer be able to  resist the
action  of offending c;uises which full health  alone
can withstand?  No matter  whether the imperfect
chyle springs from deficiency or excess, from too
weak or too strong food, from constitutional debility
or the  inroad of disease—imperfect nutrition is its
invariable  consequence, and  that  cannot  happen
without exposing the  system to morbid influences
in a greater or less degree, according to the nature
of the  constitution and other concomitant  circum-
stances.
   Wisely, therefore,  does Dr.  Clark recommend
early and  earnest  attention to a  proper  dietetic
regimen, and insist that " the food of the child be
regulated chiefly by the state of the digestive or-
gans.  In proportion  to the  delicacy of the  child,
the diet will in general require to he mild; when he
thrives upon milk, farinaceous food, and light broths,
no stronger or more substantial food  need  be used
during the first two years of life:  when he  looks
healthy and grows, and his bowels  are regular (for
this is  one of the surest indications  that the food is
suited  to  the digestive organs), we have the best
proofs  that the diet agrees with him.  When, on the
other hand, the child appears  heated  or  flushed
towards evening, when he drinks greedily and  more
than is usual in children of the same age, and when
his bowels do not act regularly, we may be  assured
that there is something wrong in the  regimen em-
ployed.
  " There is no  greater error in the  management
of children than that of giving them animal diet too
early in life.   To feed an infant with animal food
before  it has teeth for masticating it, shows a total 
 238   SCROFULA FROM  IMPROPER  DIET.

 disregard to the plain indications of nature in with-
 holding such teeth till  the  system  requires  their
 assistance  in masticating solid  food.  Before that
 period, milk, farinaceous food, and broth, afford that
 kind of sustenance which is  best  suited to the  di-
 gestive organs, and to the nourishment of the sys-
 tem.  The method of grating and pounding meat as
 a substitute for chewing, may be well suited to the
 toothless octogenarian  whose stomach  is capable
 of digesting it; but the stomach of the young  child
 is not adapted to the digestion of such food, and will
 be disordered by it. . When the child has the means
 of masticating, a little animal food may be allowed,
, but it should be of the lightest quality, and given on
 alternate days only; and even then its effects should
 be watched, for all changes in the  regimen of  chil-
 dren should be gradual.
   " The frequent origin  of scrofulous disease in de-
 fective nourishment  has led to the  opposite ex-
 treme, and children who are disposed to tubercu-
 lous disease are too often subjected to a system of
 over-feeding, which induces the disease it is intend-
 ed  to  prevent.   By persevering in  the.use of  an
 over-stimulating diet, the digestive organs become
 irritated, and the various secretions immediately
 connected with digestion are  diminished, especially
 the biliary  secretion; at least the sensible qualities
 of the bile  enable us to observe  it  best.  Constipa-
 tion of the  bowels soon follows; congestion of the
 hepatic  and abdominal veins succeeds,  and is fol-
 lowed by the train of consequences which have  al-
 ready been detailed.  It would be well if the advo-
 cates of the system of high feeding would bear in
 mind the salutary adage, corpora  impura quo plus
 nutries, eo magis ladis."*
   In proportion as the organization becomes devel-
 oped, and strength, activity, and  aptitude for abun-
* Clark on Consumption and Scrofula, p. 283. 
       BAD  EFFECTS OF CONFINEMENT.   239

dant exercise increase, a larger allowance of plain
animal food  becomes  essential  to health.  The in-
struments 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, how-
ever, even at that age; ample exercise and exposure
to the  open  air are indispensable.   By undue con-
finement to the house  or to school, and deficient ex-
posure to the air, a degree of  general delicacy is
kept up which is incompatible with the daily use of
a stimulant animal diet.   The waste occasioned by
the bodily action is too limited  to require the copi-
ous supply of any very nutritious substances, and if
these be freely allowed, they  serve only to oppress
the digestive functions and impair the health.
  The prevalent and  pernicious custom of tasking
the minds and confining  the bodies of children for
hours in succession at home and in schools,  at a
time of life when the growth of the body and  the
welfare of the system require constant 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, name-
ly, the mental excellence of the child.  The prema-
ture exertion of intellect to which it is stimulated
by the constant excitement of emulation and vanity,
far  from strengthening, tends to impair the  health
and tone of the brain, and of all the organs depend-
ing 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 distinguished men who
ever lived were in  childhood remarkable  only for
health, idleness, and apparent stupidity.  The illus-
trious  Newton was,  by his  own account, an  idle 
   240  MENTAL PRECOCJTV NOT  DESIRABLE.

   and inattentive boy, and " very low in the school,"
   till he reached 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 ge-
   nius, and were fortunately allowed to indulge freely
   in those wholesome bodily exercises, and that free-
   dom of mind, which contributed 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 distin-
   guished, and wrote his immortal epic at twenty-two
   years of age; but his life was miserable, and his rea-
   son disordered, and he  died at thirty-two.   Pascal
   is another  example  of  the same result, and Kirke
   White and many others might be named were  it
  necessary.*
    Experience, indeed, amply demonstrates, that pre-
  cocious and excessive activity of intellect and viva-
  city of feeling are most powerful impediments to
.  healthy and vigorous digestion, and consequently to
  a sufficient nutrition. In early life, therefore, when
  not only health, but future usefulness, depends main-

    * On this and kindred subjects, the reader will find much
  valuable information in Dr. Brigham's Remarks on the Influ-
  ence of Mental Cultivation and Mental  Excitement upon
  Health ; reprinted, with Notes, by Dr. Robert Macnish.  Glas-
  gow, 1836. 
        DIET  IN YOUTH  TOO  EXCITING.    241

ly on the completeness and vigour with which the
system shall proceed towards its full development,
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 miiid,' the healthy devel-
opment  of the body is  of essential importance, as
the orlly sure foundation  on which  mental excel-
lence 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 the condition  of the organization on which it de-
pends.  We enjoy acuteness of vision hy preserving
the eye in high  health, and exercising it regularly
and moderately  ; and, in like manner, we can ob-
tain and preserve intellectual power only by pre-
serving  the health of the brain, and exercising it in
conformity with its natural constitution.
  Instead, then,  of feeding the closely-confined and
excitable children of the middle and higher classes
from early infancy on quantities of stimulating an-
imal food, and even giving them wine and ferment-
ed 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 digestive power and bodily vigour by constant
exercise in the open air, before giving them a more        «
solid diet.   By these means the development of the
organization, the keenness of appetite, the tone of
digestion,  and the desire o*f, and fitness of the sys-   i
tern for, animal  food, will increase in regular pro-
portion, 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
                      X 
242    INCESSANT EATING  HURTFUL.
   which is best adapted to the condition of the diges-
   tive organs at the time when it is taken.
     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 nervous system,
   not only bear, but require a larger proportion of ani-
   mal 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 nutritive functions are more active; the
   need, consequently, for nourishing food, and the de-
   sire to  procure  it,  are proportionally increased.
   Hence it happens that, in the wealthier classes of
   society, young children suffer most from over-feed-
   ing, while in  the poorer classes they suffer chiefly
   from the opposite cause.  In both, defective nutri-
   tion is the result; but the modes  in which it  is
   brought about are very different.
     One of the  most pernicious habits in which chil-
   dren can be indulged  is that of almost incessant eat-
   ing.   Many mothers 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 digestive power of the
t   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 sensation of appetite never returns till it
   has been for some time empty.  To give food soon-
   er, therefore, is analogous to making a weary travel-
   ler walk on without the refreshment of a  halt.
      It is a great mistake to  suppose that children 
   THE YOUNCT REQUIRE NOURISHING DIET. 243

would not be quiet or contented without such indul-
gence.   On the contrary, they would be healthier
and happier were the opposite system  steadily pur-
sued.   The greatest obstacle to be encountered 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 attended to, the child will not think of eating
till  the return  of  appetite enforces the demand;
whereas, if it be left idle  and neglected, every thing
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 em-
ployment who  should  complain  that her  charge,
otherwise 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 eat-
ing will become their chief subject of contemplation.
  In a  matter so important as the rearing of chil-
dren, one would,imagine that every mother and
nurse would be anxious for instruction on the na-
ture, 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 die,
but that so many  survive their early mismanage-
ment.

  From the age of six  or seven years up to that of
puberty, when  the animal activity is at its height,
growth in full progress, and the nutritive  functions
in their greatest vigour, a larger proportion of ani-
mal food, and a more generous diet, become neces- 
244      ERRORS OF DIET  IN YOUTH.

sary  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
predominantly active for the purpose  of carrying on
growth, and supplying the rapid waste caused by
youthful activity, that if the natural craving for ex-
ercise  in the open air be freely indulged, and due
attention be given to the development  of the bod-
ily frame, the young may be very  safely left  to
choose for themselves both the quality and quantity
of their food.  In  such circumstances, the natural
taste  inclines  so essentially  to  the  preference  of
plain substantial nourishment, that there is very lit-
tle risk of excess being committed.   But where the
parents are intent only on the  intellectual advance-
ment of their  children, and accustomed to subject
them daily  to many successive hours of confine-
ment and study, with only an hour or so of relaxa-
tion  in the open air, as is too commonly the case
both with those educated at home and with those in
boarding-schools, an artificial state of being is indu-
ced, which makes the rule no longer applicable, and
renders necessary a  more careful attention to die-
tetic regimen.
  Among  the  higher  classes of society the unre-
stricted use of the most exciting kinds  and prepar-
ations of animal food, and the daily use of wine,
are the means generally resorted to for  the removal 
         ERRORS  OF DIET IN  YOUTH.     245

of the delicacy thus engendered; but when we con-
sider the real state of the case, no remedy can seem
more  preposterous.  The evil to  be corrected  is
imperfect nutrition and the want of strength.  The
imperfect nutrition, however, is caused, not'by de-
ficient food, but by impaired powers of digestion
and assimilation, and these suffer only because the
lungs  are denied the free air? the muscles their ne-
cessary 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 admin-
istering stronger food than it has the power of di-
gesting, 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 propor-
tion as  the stomach was  strengthened, to  adopt a
more  nourishing  diet, suited to  the increased effi
ciency of all the animal functions.
  By running counter to this method, and using high-
ly stimulating food improperly, many young people
of the wealthier classes  incur  as  much  suffering
from imperfect nutrition, and the diseases to which
it predisposes, as if they were really the victims of
an empoverished diet.  Dr. Clark, after making some
very judicious remarks on the influence of bad di-
gestion in inducing the consumptive constitution  ol
body, expresses himself  strongly on the evils  to
which 1 have just alluded.  "  Food in excess," he
says,  " or  of a kind too  exciting for  the digestive
organs, may also induce tubercular cachexia,—a cir-
cumstance which is not sufficiently attended to,—I
may say, not generally understood, even by medical
men; nevertheless, I hold it to be a frequent cause
of scrofula, and believe that it produces the same ef-
fect on the system as a deficient supply."—" The
imperfect digestion and assimilation in the one case,
and the inadequate nourishment in the other, being
                     X 2 
246     ERRORS OF  DIET  IN YOUTH.
equally injurious; the form and general characters
which the disease assumes may differ, but the ulti-
mate  result will be  the same in both cases.   The
adaptation of the food, both in  quality and  quan-
tity, to the age of the individual, as well as to the
powers of the digestive organs, is too little consid-
ered ; 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
nourishing diet for  the  young, is, from mistaken
views, much more  prevalent than it  ought to be,
particularly  in  female boarding-schools,  where, as
already mentioned, the system of diet is often in-
sufficient for due sustenance 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, in-
deed,  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 re-
turn home in full health after spending two or three
years at an ordinary English boarding-school.j
  It is true, that much of this result  is owing to
excessive confinement, neglect of cheerful exercise,
ill-ventilated sleeping apartments, and other depres-
sing 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 impaired digestion,
which seldom  fails  to  ensue where  the laws of
health are so widely outraged.
  \ have seen some striking instances of incurable
scrofulous disease induced by the depressing- influ-
ence  of misfortune, added to the want of a sufficient
supply of nutritious food.   After  the mercantile dis-

  * Clark on Pulmonary Consumption and Scrofula, p. 230.
  t Dr. Forbes in Cyclop. Pract. Med., vol. i., p. 698,foot-note. 
   ADAPTATION OF DIET TO CONSTITUTION.  247

asters of 1825-6, many cases of this kind occurred,
especially in families whose sensitive feelings in-
duced them to  shrink /rom public observation, 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 structure 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 attacked.
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 mo-
mentary  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 con-
stitutions in mature age, I have  already confessed
that I have little information to  offer.  In determin-
ing 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 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 more  proper than if there  is no such excess.
Where, on  the other hand, the nervous or sanguine
temperament preponderates, a plainer and  less ex- 
248 ADAPTATION OF DIET TO CONSTITUTION.

citing regimen will be necessary than where the con-
stitutional tendencies are more equally balanced.
  The power we possess of modifying the constitu-
tion by well-directed regimen is very great, and only
requires to be investigated and made known to have
due importance assigned to it in conducting physical
education.  This  is well exemplified in the art of
training, where diet and  exercise are reduced to a
practical  science  for the attainment of certain re-
sults! and with remarkable  success.  In the hands
of a trainer, the breathless and oppressed frame of
a person overburdened with lymph and fat, speedily
becomes  converted into an  active, firm,  and well-
conditioned  organization, exhibiting 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 con-
ceive the degree of improvement which would follow
the uniform observance of proper regimen and diet-
etic 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 possess a
degree of importance of which at present scarcely
a suspicion is entertained.  They constitute, in fact,
the very foundation of a systematic education;  and
mere  intellectual cultivation will fail to produce its
full beneficial results, till the organization by which
the mind operates be itself improved by a treatment
in harmony with its own constitution.
  If it be impossible for me to communicate suffi-
cient information to enable  each of my readers at
once to determine the kind of diet which is likely
to suit him best, it will give him at least some satis-
faction to know, that, by observing personally what
kind of food agrees best with his stomach and con-
stitution, he may soon obtain the necessary inform-
ation for himself.  When we refrain from eating too 
       VEGETABLES SLOW OF DIGESTION.   249

much,  and at unseasonable hours, and are not con-
scious  of any undue oppression or discomfort after
our meals, but, on the contrary, feel light and re-
freshed, and, after a time, ready for renewed exer-
tion, we may rest assured that the food which we
have taken is wholesome and suitable for us, what-
ever be its nature and general effects.  Whereas,
if, without committing any excess or other dietetic
error,  we experience the opposite  sensations  of
oppression, languor, and uneasiness, we may be just
as certain that our food, whatever its general char-
acter  for  lightness and digestibility, is  not whole-
some  or  suitable for  us  under our present circum-
stances.   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 indul-
gence, 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  diges-
tion be carefully fulfilled," the  risk of mischief from
an  erroneous choice of aliment will  be greatly
diminished.

  After the full exposition of the laws of  digestion
given in  the first part of this work, I need hardly
add, that  although there are very  few articles  of
diet which a person in health, and leading a suffi-
ciently 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, vegetables are,
generally speaking, slower of digestion than animal
and farinaceous  aliments, and consequently, when
digestion is feeble, are liable to remain in the stom-
ach till acetous fermentation takes place, and give
rise to acidity and flatulence.   Fat and oily meats
are nearly in the same  predicament,  and hence 
250      SOUPS BAD FOR DYSPEPTICS.
both form unsuitable articles of diet for dyspeptics.
Soups and liquid food are  also objectionable, both
because they are ill  adapted  for being  properly
acted upon by the gastric juice and by the muscular
fibres of the stomach, and  because they afford in-
sufficient nourishment.  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 eat-
ing soups, especially as preliminary to an otherwise
substantial  dinner; and  the fatal  epidemic which
prevailed a few years ago in the Milbank Peniten-
tiary, was distinctly ascertained to have been partly
caused by an insufficient and too liquid diet.  It is
common, indeed, to see heartburn 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 gen-
erally 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 without diffi-
culty, where, if mixed with other  substances, they
disorder  the stomach.  Dr. Abercrombie mentions
a very remarkable instance of this  kind in a gentle-
man who " had been for many years a martyr to
stomach complaints, seldom a day passing in which
he did not suffer greatly from pain in his stomach,
with flatulence, acidity, and the usual train of dys-
peptic 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,  showed such  a constant ten- 
VEGETABLES  CAUSE ACIDITY.     251
dency to recur that it has been necessary ever since
to restrict him to  a diet almost entirely of vegeta-
bles,  and in very moderate  quantity.  Under  this
regimen, so different from his former mode of living,
he  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, how-
ever, the very moderate quantity of  vegetable food
to which the patient restricted himself had perhaps
no  small share in the subsequent improvement of
his digestion.
  Dr. Beaumont mentions, as a general result from
.his experiments 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, 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  irritating  the
edges of the aperture, as is alwru/s the case when he
eats acescent fruits or vegetables."f  In another in-
stance  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 cab-
bage was 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  generally re-
ceived  opinions.  When vegetables  are  allowed,
great stress is commonly laid upon the necessity
of their being thoroughly cooked; and yet, accord-

  * Abercrombie on Diseases of the Stomach, &c, 1st edit.,
p. 73.
  t Beaumont's Experiments and Observations, &c, p. 243. 
252 FARINACEOUS FOOD GENERALLY SAFE.

ing to these experiments, 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
any thing extraordinary.  My own suspicion is, that
the  cabbage  was  not entirely  digested,  but had
merely passed through the pylorus into the intestine.
  Dr. Beaumont's  testimony in favour of  farina-
ceous vegetables is, however, more precise and sat-
isfactory.   In some of his experiments, St. Martin
digested completely a full meal of boiled rice, season-
ed with salt, in a single hour.  Soft custard and boil-*
ed rich sago, sweetened with sugar, and taken in quan-
tities 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 stomach, rendering the membrane
soft, uniform, and healthy."*  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 sys-
tem excitable, and the habits  peculiarly active, a full
proportion of vegetable and farinaceous food is prop-
er 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.

  * Beaumont's Experiments and Observations, &c, p. 249. 
          PLAIN AMMAL FOOD USEFUL.      253

  Pastry, rich  cakes, puddings, and other articles
containing much fatty or oily matter in their com-
position, are perhaps the most generally indigesti-
ble of all  kinds of food, and  consequently  ought
never to be  eaten when the tone of the stomach is
impaired.  There are state,s, however, in which oily
articles seem to agree better than lean.  I have seen
very fat fried  bacon,  for  example, digested with
ease at breakfast, where  even a small potato would
have disordered the stomach.  It is very difficult to
afford any explanationbf the fact, which, however,
is  not  uncommon.   Perhaps it is dependant on  a
peculiar state of the biliary secretion, for Dr. Beau-
mont often  remarked that the  presence  of bile  in
the stomach facilitates the digestion of fat and oily
aliments, and that, even out of the stomach, gastric
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 noticed 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  in-
duces  acidity and flatulence, and ought  not to be
used.  Venison and most kinds of game are very
suitable in the same circumstances.
  In some conditions of the system, where the con-
dition is irritable, and the mode of life not Sufficient-
ly active, red,  highly animalized meat proves too
stimulating,  although easy of digestion.  The  same
happens during recovery from  illness;  and hence
fish, chicken, and other white meats, which excite
                       Y 
254       EXPOSITION OF PRINCIPLES.
less and are digested more slowly, are often allow-
able 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 disquisi-
tions 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, it  would be making a needless  demand 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 regu-
lated, so that he may know at once why  it is for his
advantage to adhere to one course of  conduct  in
preference  to another in regard to it—why, in differ-
ent situations, diet requires to be modified in order
to adapt it more effectually to the varying wants of
the system—and, lastly, the 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 sufficiently to render them sus-
ceptible of a practical application by the reader, not
only I shall 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 truthsof still greater importance to
his welfare than those which are  most commonly
treated of Mnder the title of dietetics. 
LAWS OF  ORGANIC ACTIVITY.     255
                  CHAPTER IV.

   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 towards the stomach du-
  ring digestion.—Hence less circulating in other organs.—And
  consequently less aptitude for exertion in them.—Bodily rest
  and mental tranquillity essential to sound digestion.—Rest al-
  ways attended to before feeding horses.—Hence also a natural
  aversion to exertion immediately after eating.—Mischief done
  by hurrying away to business  after meals.—Severe thinking
  hurtful at that time.—Playful cheerfulness after dinner con-
  ducive to digestion.—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;

  Having now discussed the principles by which the
number, quantity, and quality of our meals ought  to
be regulated, we have next  to consider the  condi-
tions required for the healthy performance of diges-
tion after the aliment has reached the stomach, and
to  deduce  from  them such practical rules as shall
tend to facilitate the  accomplishment of the pro-
cess.
  Among the circumstances which favour digestion,
the  observance of bodily rest and mental tranquillity
for  some time  before and after every meal is per-
haps the most important; its influence depends on a
well-known law qf 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 ac-
tion, an  increased flow of  blood  and of nervous
energy towards it immediately commences, to ena- 
256    LAWS  OF ORGANIC ACTIVITY.
ble it to  sustain the requisite degree of excitement,
and continues till some time after the activity has
ceased.  In accordance with this law, whenever food
is swallowed, the lining membrane of the stomach
becomes suffused  with blood,  and,  owing to the
greater distension of its vessels, its colour changes
from a pale pink to a deep red hue.   After digestion
is completed, and the unusual 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 rende^ 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 stom-
ach would lead us directly to the inference that it
receives an additional supply of blood when engaged
in djgestion; for the very  act of its distention by
food renders the course of its blood vessels less tor-
tuous, and the flow of  blood through  them conse-
quently more easy and rapid.  In the case of the
stomach, indeed, the increased circulation is doubly
required; 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 ne-
cessary 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 considerable.   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 after-
ward the " stomach was as full of fluids as when he
drank a pint immediately after eating ;"* and, as the

  * Beaumont's Experiments and Observations, &c, p. 185. 
LAWS  OF ORGANIC ACTIVITY.     257
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 grand afflux of
blood which takes place towards the stomach and
intestines during digestion, cannot occur without a
corresponding diminution in the quantity circulating
on  the surface and in other distant  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 circum-
stances, 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 distribution 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 re-
sumption 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.   Among the lower creatures,
the sluggishness induced by eating increases in pro-
portion  to the degree in  which  they gorge them-
selves with food.'  The boa constrictor, after a plen-
tiful 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  immediately after a full meal be rendered
compulsory by any external cause, such as the pres-
ence  of  danger urging to  flight,  the aliment often
remains for hours in the stomach undigested.  Again,
                       Y2 
258   QUIET  BEFORE AND AFTER EATING.

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 discus-
sion is, that rest of body and tranquillity of mind
for a short time both before and after eating are ne-
cessary, and conducive to healthy digestion.   If we
have  been engaged in severe and fatiguing bodily
exertion, or anxious meditation, just before sitting
down to a meal, the blood which was flowing copi-
ously through the vessels' of the muscles  or the
brain  to keep up their unusual action, still continues
to do  so,dbecause a sufficient interval has not elapsed
to allow, the excitement to subside, and  a  new dis-
tribution to take place towards the organs concerned
in digestion.   The consequence is, that the stomach
does  not receive blood enough to carry on its in-
creased action, and furnish gastric juice with suffi-
cient  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.  Accordingly,
when we are fatigued with mental or bodily labour,
we are naturally impelled to seek repose before sit-
ting down to table;  and if we yield to this instinct-
ive 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 advantage of appropriating
half an hour to any light occupation, such as dress- 
             REST  BEFORE EATING.         259

ing, before sitting down to dinner.  If, however, we
have previously been engaged only in very moderate
exercise, an  interval of repose is not required, be-
cause then there is no undue excitement elsewhere
to retard the necessary flow of blood and nervous
energy towards the internal organs.
  The practical rule of avoiding serious exertion of
mind  or body  immediately after eating, which is
directly deducible from the physiological law above
explained,  has long been acted upon in our treat-
ment of the lower animals; and no one who sets any
value on the lives of his horses or dogs, ever allowa
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 man-
aging recruits, on a march, in this respect, 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, syste-
matically kindles his fire, cooks  his victuals, and
makes his arrangements for the night, with a cool-
ness of deliberation which  surprises the recruit;
and he is amply repaid for his temporary self-denial,
by the greater enjoyment and support which he de-
rives from  the very same materials which the impa-
tience of the other has caused him in a great meas-
ure to waste.
  Let any one who  doubts the advantages resulting 
260  ANIMALS  INACTIVE AFTER EATING.

from  attention to this  rule, consider for a moment
its  universal and scrupulous  observance by post-
masters and jockeys, and think whether these are
persons likely to throw away  time 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 valu-
able horse has been killed by being prematurely fed
after  fatiguing exercise, and man himself is no ex-
ception  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 tranquillity or of gentle bodily exercise is
eminently conducive to the healthy  action of the
stomach, precisely because it favours the new dis-
tribution of the circulating blood which that process
requires.
  In accordance with this law of digestion, there is
throughout  the whole  animal creation a  marked
aversion to activity  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 defi-
ance,  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  whom he treats so much better than him-
self, are by his care entirely exempted.  Nowhere,
for example, does man hurry off to business so im-
mediately as in the United States of America, and
nowhere does he bolt his food so much as if run-
ning a race  against time.  The consequence is, that
nowhere do intemperate eating and  dyspepsy pre-
vail to the same enormous amount.  Even  in  Eng-
land, according to Dr. Caldwell, the extent of trans-
gression cannot be compared with what is witnessed 
      REPOSE REQUIRED AFTER  EATING.   261

among our transatlantic  brethren;  and the result
shows, that if we in Britain suffer from indulging
our fondness for good things, the comparatively de-
liberate 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 diges-
tion, what can be expected to follow but inveterate
dyspepsy ]
  The reason why wounds,v bloodletting,  bathing,
and other circumstances which tend to disturb the
regularity1 of the circulation, are so hurtful after a
full meal, will  now be  apparent.   The  effect  of
wounds and  bloodletting is to give rise to an instan-
taneous 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 ex-
tends over the whole  time  of the continuance of
food in the  stomach.  After a moderate  meal, and
in ordinary  health, the concentration of the  vital
powers in that organ,  and their proportionate de-
pression  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, consequently, the  same quantity
of blood is no longer required to be directed towards 
262 NERVOUS ENERGY DURING  DIGESTION.

the stomach, but may beneficially be distributed to
such other parts, as from their activity more imme-
diately 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
be sent to the  brain without robbing the stomach.
The same principle of course applies to all the other
organs; and it is therefore 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
essential.
  As already mentioned, the reality of increased cir-
culation in the vessels of the stomach during diges-
tion 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 seen.  It is  the
almost characteristic feature of the nervous system
to be  excited by stimulus to  increased action; and
we formerly saw that when the nerves of the stom-
ach are cut, and the flow  of nervous influence is
arrested, digestion instantly suffers.  But the same
principle holds in the nervous as in the  circulating
system.  Energetic action cannot be kept up in two
distant partsof the body at the same time.  If the
intellect be intently occupied in profound  and ab-
sorbing thought, the nervous energy will be concen-
trated 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 difficulty 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 
     NERVOUS ENERGY DURING DIGESTION.  263

one, there will be much less difficulty in simultane-
ously proceeding with both, because comparatively
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 prop-
erly exercised in all its departments of feeling and
affection as well as of intellect, the nervous influ-
ence which  the brain produces  is not only more
abundant, but of a more healthful and invigorating
quality.  Hence the well-known preservative and
restorative  influence  of  cheerful dispositions and
gratified activity of mind, and hence the depressing,
morbid, and  often fatal eflects of corroding care,
grief, or apprehension, on every  organ of the body.
Hence, too, the weak digestion and sallow com-
plexions of literary men and hard students,  who
suffer severely from transgressing this law of the
animal  economy  by habitually engaging in occupa-
tions  requiring  much exertion  of mind,  not  only
soon after, but even during the very act of swallow-
ing their meals.  Ignorant of the connection subsist-
ing between the different functions, and of their laws
of action, few can be convinced  in time of the im-
portance of observing  this  condition, even after its
operation has been explained to them.  In the con-
clusion, however, experience teaches many  whose
reason  is insufficient 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 digestion  is familiarly and  unequivocally exhib-
ited in  almost every case of dyspepsy which each
succeeding day brings under the  notice of the phy-
sician.  He knows well from  experience 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 re- 
 264 NERVOUS ENERGY DURING DIGESTION..

 lieve, unless his patient be at the same time freed
 from the pressure of care,  and due attention be de-
 voted to the observance of  mental and bodily repose
 after, every meal.  The heavier the meal the greater
 is the desire for absolute rest, and the less advan-
 tageously  can  active  exertion  be  encountered.
 When the stomach is loaded, the whole  vital ener-
 gies seem  to be concentrated  in it to enable it to
 cope with the task imposed upon  it.  But when we
 eat temperately, 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 gastric juice,
 less nervous energy, and less vigorous 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 min-
 utes for meals, indigestion is very prevalent.  Ordi-
 nary 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 position, is
 taken leisurely, and costs no effort.
  Those who are  compelled by  circumstances to
 active  exertion 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 experience,  and some of  them
 have  specially  noticed  its importance.  Richard
 Cumberland, for example, in  speaking of his own 
INFLUENCE  OF THE  MIND.        265
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 morn-
ing."*   This compatibility of temperate eating with
activity did not escape the acute observation of Hip-
pocrates.
  The state of the mind, indeed, exerts a powerful
influence not only on the stomach, but on the whole
process of nutrition, and greatly modifies the quan-
tity which may be safely eaten.  If the mind be gay
and  joyous, appetite will be comparatively keen,
digestion effective and rapid, and nutrition complete.
Examples  of this kind  abound in childhood, and
among an easy-minded, well-fed peasantry. Whereas
if the mind be harassed  by care and anxiety, or de-
voured  by grief, envy, jealousy, or other troubles
and  disquieting passions, the healthy calls of appe-
tite will be scarcely known, and digestion and nu-
trition will be equally impaired.  This fact is exem-
plified on a large scale in every commercial 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 are 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.
       Ccesar. Would he were fatter : but. I fear him not:
     Yet 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 loves no plays,

         * Cumberland's Memoirs, vol.  ii., p. 204.
                        z 
 26r>      INFLUENCE  OF  THE  MIND.

      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
      That could be moved to smile at anything.
      Such men as he be never at heart's ease
      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, unburdened, 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       j
 some important scheme.   There cannot be a doubt,       i
 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 exercise  in the
 open air, to impair the tone of the  digestive organs.
 In this way, as it is  not less justly than forcibly re-
 marked by Dr. Caldwell, "dyspepsy commences, per-
 haps, as often in  the brain as in the stomach.  Pos-
 sibly oftener.  That this is  true  of the disease in
 Europe will scarcely be denied, after a fair examina-
 tion of the  facts connected with it.   It is  there       \
 almost  exclusively a complaint of the studious and
 the scheming, who, over-tasking their brains, injure
 them by toil.   Among the husbandmen of England,
 who steadily  pursue their tranquil mode of life, re-
 gardless of the fluctuations of stock, the bickerings
 of  party,  the  fate of political measures, and  the
 changes of place, dyspepsy is almost a stranger."
 11 In the cities, the same is in a great measure true
 of  merchants,  manufacturers, and mechanics, who
 are engaged in a regular and well-established busi-
 ness, 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 
           INFLUENCE OF  THE  MIND.       267

digestion, and bear the marks of it.  But with liter-
ary  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.   Dys-
pepsy 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 as
respects quantity, quality,  and cooking, than the
classes  to  whom dyispep^y  is  unknown.   This fact
is notorious, and  has  been  so for centuries.  Nor
can  it be attributed, 1  think, to any other cause but
excessive  and*deleterious cerebral irritation in the
one  case,  and an exemption  from it in the other;
and  this  cause  seems sufficient to solve the pro-
blem."*
  In denouncing active exertion  of mind or  body
immediately after eating, as  inimical to digestion, it
is not meant that we should go to sleep, or indulge
in absolute listlessness.  A  weak constitution may
require something like complete repose, but a person
in ordinary health may indulge in a leisurely saun-
ter or pleasant conversation, not only without injury
but with positive benefit;  and perhaps there is  no
situation in which digestion goes on so favourably,
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 observance of the  condition here adverted to,
continue to live and digest for years without appear-
ing to suffer much from their conduct.  But it is not
less  true  that there  are many more  who  bring

   * Caldwell's Thoughts on Physical Education, p. 94. 
268 ADVANTAGES OF FULFILLING THE LAWS.
 wretchedness and disease upon themselves and their
 offspring, in the vain attempt to counteract  the in-
 tentions of nature, and that there are comparatively
 few, even of the former, so happily constituted as to
 escape  entirely 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  conse-
 quence  resembles that arising  from breathing in a
 vitiated atmosphere.   The effect may not be per-
 ceptible for a time ; 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
guarantee that every departure from them must be in.
so far hurtful, however slowly the effect may devel-
ope itself. 
RULES  FOR GRATIFYING THIRST.    269
                  CHAPTER V.

                     ON DRINKS.

Thirst the best  guide in taking  simple drinks.—Thirst in-
  creased by diminution of the circulating fluids.—The desire
  for liquids generally an indication of their propriety.—Much
  fluid hurtful at meals.—Most useful three orfour hours later.—
  The temperature of drinks is of consequence.—Curious fall
  of temperature in the stomach from cold water.—Ices hurt-
  ful after dinner.—Useful in warm weather, when digestion is
  completed and caution used.—Cold water more dangerous
  than ice when the body is overheated.—Tepid drinks safest
  and most refreshing after perspiration.—Kinds of drmk..— Wa-
  ter safe for  every constitution.—Wine, spirits,  and other
  fermented liquors, too  stimulating for general use, but bene-
  ficial 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 1  On both 1 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 to us for
the express  purpose of impelling us to take liquids
whenever the wants of  the  system require them,
and that, in  all ordinary circumstances,  we  cannot
have a better or a safer guide.  Such is the general
case; but exposed as we are to numerous 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  urinary  discharge, and the  various
                         Z2 
270   RULES  FOR  GRATIFYING THIRST.

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 circulation.  This
actually  happens in  Asiatic cholera, in  which the
watery portion of the blood is drained off through
the bowels with  frightful  rapidity, and  in which,
consequently, the urgency of thirst is almost always
excessive.  In  the healthy state, however, the loss
of fluid is never too  rapid  unless under  severe ex-
ertion or exposure to a very high temperature, both
being circumstances  in which it is well known that
thirst becomes  urgent in proportion to the necessi-
ties of the frame.
  In proof of the sensation of  thirst  being greatly
dependant upon the quantity of fluid  circulating  in
the vessels, Professor Dunglison of Maryland refers
to the fact, mentioned  by Dupuytren,  that he " suc-
ceeded 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 thirst of animals to which he had admin-
istered poison,  and which were  incapable of drink-
ing, 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  absti-
nence from  liquids  was  more  prolonged ;"* and
hence the greater thirst naturally experienced under
such  circumstances.
  As a general rule,  then, the desire for  liquids will
in itself  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

  * See Professor Dunglison's  Elements of Hygiene, p. 324,
in which the reader  will find a great variety  of very useful in-
formation 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. 
        RULES FOR GRATIFYING THIRST.   271

bounds, or to disturb the progress of digestion by
undue dilution too soon after eating.  Many per-
sons, from habit rather than thirst, impair the tone
of the stomach by drinking largely during or imme-
diately after meals, and thus relaxing the mucous
coat, and probably affecting the quality of its secre-
tions.   If the  gastric  juice be  greatly diluted  by
extraneous fluids, it is natural  to suppose that  its
solvent power mitst be diminished;  but whether
this  explanation  be sound or not, the practice  of
drinking frequently is  certainly  hurtful, and there-
fore  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
the 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 stimu-
lus never fails  to  induce, especially  at night.  The
continual  dilution, however, adds to the  mischief,
by increasing the debility  of the stomach, and, as
pointed out in  the chapter on thirst,  the only effect-
ual  remedy is to adapt the  diet  and regimen  to
the real wants of the constitution.   Except in dis-
ease, a continually recurring  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  al- 
272      TEMPERATURE OF  DRINKS.

most universal use of tea or coffee about that time
appears to sanction its soundness.  Theoretically,
too, we might  expect this result; for digestion is
then nearly over, and any food remaining  in  the
stomach is already in a  fluid  state.   Many  objec-
tions, however, have  been made  to both tea and
coffee as  an evening  beverage; 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  ex-
penditure of the system—by perspiration,  urine,
and exhalation from the lungs—is  of a fluid nature,
and hence there is a marked and general preference
of fluids as a part of our first meal.  In this coun-
try, 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 sub-
stances  coming in contact with them are apt to be
injurious.  As regards the stomach, the  same prin-
ciple holds true;  and when we consider the  multi-
tude and  intricacy of its nervous connections with
other vital organs, we cannot  be surprised at even
sudden- death being frequently caused by drinking
ice-cold water when the body is weakened by pro-
fuse perspiration.  Of the various subjects connected
with digestion on which  Dr. Beaumont has thrown
light by his experiments on St.  Martin,this is  one of
i 
TEMPERATURE  OF DRINKS.      273
the few which he has omitted to investigate with
his usual diligence and accuracy; a circumstance
which is the more remarkable, because an inciden-
tal observation of his own seems, from its singularity,
to have been well calculated to direct his attention
to its consideration.   On  the  occasion alluded to,
when a gill of water, at  the  temperature of 55°
I'ahr., 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
slowly.  It was not till thirty minutes had elapsed, and
all the water been for some time absorbed, that the mer-
cury 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 perspiration and fatigue, is often instantly fatal;
but its operation has never beensatisfactorily ex-
plained.  The above  experiment, however, throws
some light on it;  for if a single gill of  water at 55°
(which is not by  any means a low temperature) is
able to reduce the heat of  the stomach in a moment
by no less than  twenty-nine degrees, when neither
fatigue nor perspiration is present to add  to its ef-
fect,  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 un-
doubtedly be much more powerful 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 extensive fall of temperature is greatly 
274    ICES  HURTFUL  AFTER A MEAL.
       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 nervous connec-
       tions given for the express purpose of extending the
       range and directness of its sympathies.
          Keeping in mind the great depression of temper-
       ature caused by swallowing so small a quantity of
       cold water, and also the ascertained fact that a heat
       of about 100° is requisite  for healthy digestion, we
       shall have no difficulty in accounting 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 in-
       stantaneous contraction and diminished action of its
       blood vessels, the  consequent stoppage of the gas-
       tric 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 through-
       out,  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 ar-
       rest 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 teaspoonfuls 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 enjoyment of sound
       digestion.  Many eat them in this way and  are lit-
       tle the worse ; partly from the subsequent reaction
       being sufficient to  counteract  the  depressing  influ-
       ence, and partly from a person in vigorous health 
       ICE USEFUL WHEN PROPERLY USED.   275

being able to throw off causes of disease from which
those who are less robustly constituted suffer se-
verely.   My belief, however, is, that the tendency of
ices,  taken  in such circumstances,  is to produce
mischief.  A healthy person, for example, may pos-
sess vigour enough to escape injury from immersion
in cold water, caused by tke ice giving way when
skating; but as well  might  it  be  inferred, on that
account, that a similar immersion would be general-
ly innocuous, and even salubriods, as that  all may
safely eat ices freely because a  given individual has
done  so with impunity.   Dr.  Beaumont's experi-
ment with the cold water shows clearly that the
effect is  to lower the vital tone of the  stomach; and,
such being the case, those whose digestion  is weak
ought to be  careful against impairing it still further
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.
  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 neces-
sarily hurtful,  that with proper caution it may prove
both grateful and refreshing.  In Italy, accordingly,
ice is considered so  much  a necessary of life  in
summer, that  in Naples  and other places the con-
fectioners are  punished by a fine if they allow their
supply  to fall short.  In Virginia, too, where, we*;
are told  by Professor Dunglison, it was very com-
mon some years ago  for  the  labourers in the har-
vest field to be killed by drinking copiously of spring
water while overheated,  cases  of death have be-
come extremely unfrequent  since  the  custom was
introduced of  supplying  them with ice.   When
water was taken,  it  was always hastily  and  in
large quantity, so that the immediate effect on the
system was greater than could possibly arise from
the small  auantity of  ice  which is  required for 
276 TEPID DRINKS SAFE AND REFRESHING-

quenching thirst.  The very slowness, 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 sa-
lubrious will they become, because the less violent
will be their action upon the nerves, blood vessels,
and membranes of the stomach.  From the close
sympathy  existing between the stomach  and the
skin, a single teaspoonful of ice-cream suddenly
swallowed when the  body is weak and  perspiring,
will produce 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, also are injurious, but not
in the same degree.   They relax the mucous mem-
brane and  weaken the  action of the muscular coat,
and in so far tend to  impair 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.
  When great  thirst has been  excited either by
bodily labour or by external heat, it  will generally
be more effectually as well as safely quenched by
drinking  moderately of tepid than of cold  fluids.
A tepid draught—a  cup of tea  for example—pro-
duces no disturbing action in the stomach, and, being
immediately  absorbed,  supplies the deficiency  of
liquid without changing the balance of the circula-

       * Dunglison's Elements of Hygiene, p. 331. 
DIFFERENT KINDS OF DRINK.      277
ting fluids, thus  relieving thirst  very much  in  the
same way as Dupuytren did by injecting tepid water
into the veins; whereas cold drink, by the sudden-
ness 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  allow  post and stage-coach
horses a little water before their run  is completed,
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 considerable disturbance  in the balance
of circulation, and  thus  ensures the safety of  the
animal.   If even the same moderate quantity were
given at the end of  the stage, and the horse were
then allowed to  rest, inflammation would almost in-
evitably result.
  The same principle  applies to the human frame,
and affords an easy  explanation of the occasional
instances  we  see of  persons heated  by  exertion
drinking cold water  without  injury,   If the exer-
tion have  been merely sufficient to produce excite-
ment  without fatigue, and  heat  without debilitating
perspiration, and  especially if it be resumed after the
draught, little or no harm will  ensue.  But if  ex-
haustion  or  fatigue  have been induced, and  the
individual be  allowed to  drink  freely of  the cold
water and then rest, the probability of mischief re-
sulting  from  it  will  be greatly increased.  Many
accidents result from losing sight of this distinction,
and from  acting alike in circumstances  so essen-
tially different. 
278   EFFECTS OF FERMENTED LIQUORS.

  On the  subject of the kind of drink which  ought
to be taken  a  great deal might be said,  were  it
necessary to discuss here  the  qualities of all the
liquors that are in use.  But as my purpose is very
different, a few general remarks  will be enough.
  Water is a safe drink for  all constitutions,  provi-
ded 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 de-
sire 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 simi-
lar kind, which are little stronger than pure  water,
may be used, according to the same general  princi-
pie, by those who prefer them and find them  agree-
able to the stomach. But with  regard to  such fer-
mented 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 ana1 quicken
the circulation.  In all conditions, therefore, in which
the action of those  requires  to be increased or sup-
ported, they are calculated 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 constitu-
tional state.
  In infancy and childhood the circulation is rapid
and  easily  excited, and  the  nervous system  is
strongly acted upon even  by  the slightest exter-
nal impressions.  Hence slight causes of irritation 
  WHEN ARE FERMENTED LIQUORS USEFUL? 279

readily excite febrile and convulsive 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 so imperfectly constituted as to
require some stimulus to rouse the system to healthy
action, and to whom wine is beneficial  as  a  medi-
cine.   But these are the  exceptions to the general
rule,  and to them  it should be  given  only  under
medical sanction.
  In youth the natural tendency of the constitution
is still to excitement; and consequently, as a gen-
eral rule, the stimulus of fermented liquors is inju-
rious.  During rapid growth, however, the animal
functions are sometimes so enfeebled by the great
demands made upon them, that not only a full sup-
ply of  nourishing food,  but also  an allowance of
 wine or 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 in-
creasing nervous sensibility; 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 circu-
 lation 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 excitement only
 increases  the  wasting  of  the  natural strength.
 Where, however, the system has been long accus-
 tomed  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 
280    WINE PREFERABLE TO SPIRITS.

begin to fail, moderate stimulus may be used with
evident advantage.
  If it be said that this  doctrine amounts to a vir-
tual prohibition of wine and stimulant liquors, I ad-
mit at once that, where the whole animal functions
go on healthfully and energetically without them,
their use is, in my opinion, adverse to the continu-
ance  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 occa-
sional use.  If,  for example, a healthy person  is
exposed to unusual and  continued exertion  in the
open air, or to the influence of anxious and depress-
ing watchfulness, a   moderate quantity of  wine
along with  his  food  may become the means  of
warding off actual disease, and enabling him to bear
up uninjured, where without it he would have given
way.   This preservative influence has been so often
experienced, that it is  impossible to deny its reality.
  While, then,  I consider stimulating liquors  of
every kind as both useful and hurtful, where with-
out them the system  is  healthful  and  energetic, I
can see no reason why their temperate use in cir-
cumstances of an opposite nature ought to be denied.
Many  weak  constitutions and many invalids are
benefited by wine, and all that can reasonably be
demanded 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 innocuous, 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 
         WINE PREFERABLE TO SPIRITS.     281

fever, take to  the extent of a bottle of Madeira in
twenty-four hours,  without producing the least un-
due excitement of either the mind or the pulse, but
rather the contrary—it soothed the mind and reduced
the pulse ;  and this I 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 effected 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
incessant craving for more when  the system  has
once  been  accustomed  to them.  Ardent spirits,
therefore, ought to  be used only as a medical rem-
edy.  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 adminis-
tered with a recklessness which savours strongly of
barbarism, and the  consequences  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 should
be  on their guard  against  directly or indirectly
encouraging, in their patients, a practice so utterly
destructive  to both  physical and moral  happiness.
For, in  some  instances, it  is to be feared  that the
                      Aa2 
 282   EFFECTS OF WINE ON THE  STOMACH.

 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 indulging 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  temperance.
 These  efforts  have been followed with astonishing
 success,  and  the  good which has  been  already
 effected is immense. It seems to me, however, that
 much more might be accomplished,  if we  did not
 confine ourselves so exclusively to the  mere incul-
 cation  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 reforma-
tion, when once effected, might 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 temptations, 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 relapse will continue to be great.  The impor-
 tance of  this principle is  perhaps  not sufficiently
 recognised in the otherwise  valuable labours of
 temperance societies*
  Many persons imagine that spirits, taken in mod-
 erate quantity, cannot be injurious,  because they feel
 no immediate bad effects from their use.   If the fun-
 damental 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 
    EFFECTS OF  SPIRITS ON THE STOMACH.  283

against this obvious  truth.   The  evil  attending
their unnecessary use may not be felt at the mo-
ment,  but  nevertheless  it  is  there;  and  for  de-
monstrative proof  of the fact, we are  again in-
debted 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 (in-
flammatory) and aphthous  (ulcerous) patches,  the
secretions vitiated, and the gastric juice diminished
in quantity, viscid, and  unhealthy;- although St.
Martin  still complained of nothing,  not even of im-
paired appetite.   Two days  later, when the state of
matters was aggravated, " the inner membrane of the
stomach was unusually morbid, the erythematic appear-
ance 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 covering 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
muco-purulent discharge slightly tinged with blood, re-
sembling the discharge from the bowels in some cases of
dysentery.   Notwithstanding this diseased appear-
ance of the  stomach, no very essential aberration of
its functions was manifested. St. Martin complained
of no symptoms indicating any general derangement
of the  system, except an uneasy  sensation  and a
tenderness at the pit of the  stomach, and some ver-
tigo, with   dimness and yellowness of vision, on
stooping down and rising again; hadja thin yellow-
ish-brown coat on his tongue,  and his countenance
was rather sallow; pulse uniform  and regular, ap-
petite  good; rests quietly, and sleeps  as usual." *
  I have  marked part of this quotation  in  italics,
because it cannot be too attentively considered by

  * Beaumont's Experiments and Observations, &c, p. 237. 
 284     STATE OF STOMACH IN FEVER.

 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 exter-
 nal signs.  Here we have incontestible  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 few days of intemperance
 in a person of*a sound  constitution, 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  se-
cretions became natural, the gastric juice clear and
abundant, and the appetite  voracious.  Dr. Beau-
mont adds, that, in the  course of his experiments,
diseased  appearances of a similar kind  were fre-
quently observed—generally, but not  always, after
some appreciable cause.  " Improper indulgence in
eating and drinking has been the most common pre-
cursor of these diseased conditions of the coats of
the  stomach.  The free use  of ardent spirits, wine,
beer, or any  intoxicating liquor,  when continued  for
some days,  has  invariably  produced   these  morbid
changes.  Ealing voraciously or to excess,  swallowing
food coarsely masticated or too fast," " almost invari-
ably produce similar effects, if repeated a number of
times in close succession."—(P. 239.)  These  ob-
servations mjuire no  comment; their  practical
bearing must be obvious to  all who  are willing to
perceive  it.
  Dr. Beaumont had also  frequent occasion to re-
 mark,  that, when  stomachic  disorder,  attended
 with febrile symptoms, was present, the  mucous
 coat of the stomach presented distinct appearances 
       FERMENTED LIQUORS CONSIDERED.   285
                                            •
of disease.  He frequently saw it, for example, 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 before.   Even anger and  violent men-
tal  emotions  sometimes  produced  these, appear-
ances,  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, however, bland fluids are
appropriate;  because they allay irritation, 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, induced by drinking ardent spirits, and by
general intemperance, 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 striking
and important truths.

  If it be asked whether I  go the  length of pro-
scribing all fermented liquors, from table beer up-
ward, 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 
286
EFFECT OF DRAMS.
wine  or  such other fermented liquor as should be
found by experience to support the strength, without
quickening the circulation, exciting the mind, or dis-
ordering the digestive functions.  If, however, any of
these effects  be produced, I would consider its
occurrence as a proof that  the stimulus is inappro-
priate, and cannot be too soon discontinued, or at
least  diminished  to  such 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 moderation in eating,  there
would be some apology for our conduct. 
REGULATION OF THE BOWELS.      287
                 CHAPTER  VI.

     on the proper regulation of the bowels.

Functions of the intestines.—The action of the bowels bears 3
  natural relation to the kind of diet.—Illustrations.—And als:
  to the other excretions.—Practical conclusions from this.—
  Different causes of inactivity of bowels.—Natural aids to in
  testinal action.—General neglect of them.—Great importance
  of regularity of bowels.—Bud 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 mode 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  intentions of
nature for our welfare and happiness,  I have  only
to add a few practical remarks on the proper man-
agement of the bowels, and then conclude.
  The proper uses of the intestines are, as we have
seen, to  serve, 1st, for the performance of  chylifi-
cation ;  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 chylification
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 chan-
nels by which the waste materials of the body pass 
288     REGULATION OF THE BOWELS.
out.   The  most important of these are the skin,
the lungs, and the kidneys; and  in certain circum-
stances, 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 consequence, the urinary
secretion  and the exhalation from the  lungs  are
both  increased, and full relief to  the system is tem-
porarily  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  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 indigest-
ible portion of the food, and of  waste  matter from
the  system, it follows that, in  health, their  action
ought to bear  a relation 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 individual, may be
very far  from presenting the   same character at
another  time, and in a different  individual.  If, for
example, a person be fed chiefly on milk, rice, or
farinaceous aliment, which is almost entirely appro-
priated to  the purposes  of nutrition and leaves very
little residue, the bowels, having little to throw out, 
          REGULATION OF THE BOWELS.     289

 will naturally act seldomer and less fully than when
 the  diet consists  chiefly of  bulky and  innutritious
 vegetables, which leave a large portion  of indigest-
 ible 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 con-
 clude  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 intes-
 tinal action consequent on an exclusively farinaceous
 diet is then the natural and healthy result; and ac-
 cordingly, where  such diet is  required, the  mere
 costiveness is attended with  no injury  to the con-
 stitution.  The proper conclusion to be  drawn from
 it is, that the permanent  and exclusive  use of con-
 centrated food is not in harmony with the structure
 and  functions  of our digestive  and assimilating or-
 gans, 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
 organization by which it is to be acted upon.
  The same remark  applies to those who  are ac-
 customed to dine chiefly on animal food, and rice or
 bread, without any sufficient admixture  of herbace-
 ous or other innutritious substances.  If, in such cir-
 cumstances, the aliment is 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 
290     REGULATION OF THE BOWELS.

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
instances in which the stomach is unable to digest
any vegetable or innutritious food, and in which,
conseqently, the diet cannot be altered without in-
jury.   1 admit that, in the present state of society,
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 intrinsic im-
portance deserves.  There are very few individuals
who, when in health, and with the aid  of a proper
regimen, cannot digest aliment suited to the natural
constitution 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 laxatives, or such other reme-
dies as the circumstances may require.
  As the frequency and amount of the  intestinal
evacuations may thus vary according to the nature
of the diet, without necessarily involving any dis-
turbance of health, so may they also vary .accord-
ing  to the  state of the other excretions ; 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 ex-
cretion  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  in-
creased  exhalation from  the skin also  to continue,
the  system would speedily  become reduced.   In
consumption,  for example, exhausting  bowel com-
plaint and  profuse perspiration are  frequently ob-
served to alternate, and whatever remedy is given
to check  the one  generally aggravates the  other. 
          CAUSES OF INACTIVE BOWELS-     291

 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
 functions, 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 ex-
 cess, 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 irri-
 tate and weaken.
   The mere fact of the bowels not being emptied so
 frequently 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 in-
 testinal canal, or is the  natural result of an  acci-
 dental change of diet, or temporary excess in the
 other excretions ; because the remedy which is ap-
 propriate  and efficacious in  the one case,  may be
 altogether inapplicable  to  the other.   Where  it
 arises entirely from the aliment leaving little resid-
 ual 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 in-
 action, 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  derangement of the stomach and  bowels
 as their source, and from the scarcely less universal 
292     CAUSES OF INACTIVE  BOWELS

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 re-
gularly every day; and the inference would, to a
certain extent, be confirmed by  the  acknowledged
extensive utility of laxative medicines.  The real
state of the case, however, is not quite so simple;
and as it is of importance that it should be under-
stood, 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 excretions.
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 suf-
ficiently equal to leave a considerable quantity of ali-
mentary residue and effete matterto 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 ex-
pect to succeed in restoring the natural action.  To
learn how we may discover what  that obstacle  is,
Jet us turn our attention for a moment to  the natural
means by  which  the  intestinal  evacuations  are
effected.
  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 mus-
cles, 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 unfulfilled, the  inevitable result will be morbid
sluggishness of the intestinal  action, and the vari-
ous consequences dependant on it; and hence, when 
          AIDS TO INTESTINAL ACTION.      293

the evil  exists, the first point to be determined is
the nature of the cause by which it is produced.
  As already remarked, farinaceous and other con-
centrated aliments do not afford the requisite stim-
ulus 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 costiveness, the proper remedy
is to alter the  diet, and to  have recourse to other
means only where that proves insufficient.
  Where, however, as most frequently happens, the
constipation arises not so much from an inappropri-
ate diet as from the absence of all assistance  from
the abdominal and respiratory muscles, the first
step to be taken is again to solicit their aid—first,
by  removing all  impediments to  free respiration,
such as stays, waistbands, and belts ; and, secondly,
by resorting  to such  active  exercises 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 sys-
tematically and perseveringly, 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 muscles 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 to
the punishment inseparable from disobedience, and
Bb 2 
294     AIDS TO INTESTINAL ACTION.
 merely endeavour to  mitigate its severity  by such
 partial remedies as lie within our reach.
  Where  bodily weakness, or any other cause, ab-
 solutely prevents us from engaging in active bodily
 exertion, continued kneading and rubbing over the
 region of the bowels, when used daily and perse-
 vered  in  till the strength is restored,  is  of great
 service in promoting their healthy action.   Where
 great sluggishness of the bowels exists,  and no ex-
 ercise can be taken, the rubbing generally requires
 to be continued for an hour or more daily, or even
 twice a day.
  The observance of a proper adaptation between
 the  quantity of the food and the state of the diges-
 tive organs and mode of life, is not less essential to
the  proper action of the bowels than to  that of the
stomach.  If the  quantity be too great, 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.
  Sometimes intestinal inaction  proceeds from de-
fective mucous  secretion on  the surface  of the
internal coat, caused either by errors in diet or by
local irritation.   When costiveness  is  excited  in
this way, a mild diluent regimen will generally re-
move it.   It is in such cases that saline medicines,
which act by increasing the mucous secretions, are
often very useful; while aloetic and other stimulant
purgatives increase the  evil by aggravating the ir-
 ritation.
  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 to every kind of costiveness, no
 matter from  what cause  it  proceeds   If  a clerk 
     REGULARITY OF BOWELS IMPORTANT.   295

who sits  motionless all day in an office, who in-
dulges his appetite, and has no bodily exercise to fa-
cilitate respiration and give a natural impetus to the
bowels, begins after a time to complain of constipa-
tion, it is not difficult to tell what is required for his
cure.   The  first  step which a  knowledge pf the
animal functions suggests, is to diminish the quantity
of food ;  the next, to use such  a diet  as is calcula-
ted to excite the  muscular coat of the intestine to
healthy activity; the third, to seek the natural aid
arising from exercise  of the abdominal and respira-
tory muscles; and the last of all, to have recourse,
when necessary,  to such  medicine as  may be re-
quired  for a time to restore the tone of the bowels.
and enable them  to act without further assistance
The course  usually  adopted,  however, 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 hard  fate in possessing such a  bad constitution,
and resorting 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 unfortunate results.  In them the evil  is
aggravated  by the tightness of their clothing impe-
ding almost entirely the descent of the diaphragm,
and the free play  of the abdominal muscles, in res-
piration.
  From this view of the nature and causes of cos-
tiveness, 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 
296  REGULARITY OF BOWELS IMPORTANT.

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 in-
stant  recourse to  medicine, but to  begin by dis-
covering and  amending the defect.   In the rare
occurence 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 attaching great importance to the proper regula-
tion 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 ar-
rangements 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 happens, for example, that, from
debility of  the muscular coat, the peristaltic motion
is insufficient to  propel the contents of  the intes-
tines  even with the aid of proper diet and exercise.
In such cases, small doses of aloes  or rhubarb, or
other laxatives  which act chiefly by exciting the
muscular 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, may be given freely, and even
cause numerous watery evacuations,  and yet the
real  or  solid  contents of the intestines 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. 
      REGULARITY OF BOWELS IMPORTANT.  297

  The period of life at which  intestinal inactivity
is attended  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 ac-
tivity of youth to  all  the stillness of a sedentary
profession,  without  any  corresponding 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 individ-
ual to eat an amount of food far beyond the present
necessities  of the system.  The consequence is a
tendency, not  only  to fulness from excessive nu-
trition,  but  to  severe  digestive disorder from the
stomach and intestines being weakened both by want
of exercise and by excess of food.   I  have known
many  instances  of  dyspepsy,  constipation, and
mental  affection, and  even of active inflammation,
thus produced.  In one case, four years of contin-
ued bad health in  an otherwise sound constitution
were the penalty inflicted before the real cause was
accidentally discovered.   During all that time, too,
temporary relief invariably followed the use of pur-
gatives, and seemed  in some  measure to point to
the truth; but, from 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 at-
tention  of his medical advisers.
  In cases of  this  description, however, it ought to
be observed, 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 
298  REGULARITY OF BOWELS IMPORTANT.

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 unimpor-
tant 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 nerv-
ous system, is powerful in modifying the result, and
in sustaining healthy action when once  fairly es-
tablished.   Hence the obvious advantage of observ-
ing as much regularity in relieving  the system as
in taking our meals, and the impropriety of attempt-
ing 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 morning, 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  ex-
perience  the inclination immediately after their
morning repast, and suffer if they are prevented
from yielding to it.
  Where either from constitutional weakness, se-
dentary occupation, or  other  unavoidable  causes,
the bowels are unable to act sufficiently to relieve
the system without assistance, we have, of course,
no choice  but to select that which is most  suitable
to the circumstances and most gentle  in its oper-
ation ; 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 medicine alone  for recti- 
            CONCLUDING REMARKS.        299

fying the consequences of the patient's misconduct.
We ought, in short, 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 medicine 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  economy, and with the means  by
which aberrations  from them maybe 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 further
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 intro-
duced 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 prevailing
ignorance on subjects which, although in themselves
as interesting  and important as any to which the
human mind can be directed, have nevertheless been
passed  over in silence,  partly from not the  least
suspicion being generally entertained of their real 
300          CONCLUDING REMARKS.
bearing on our health and happiness, and partly also
from  false notions of delicacy diverting  attention
from  their calm  and deliberate examination.   In
endeavouring, therefore, to unfold what I  conceive
to be  useful truths, in the language of reason, I con-
fess that I feel no apprehension that any well-con-
stituted mind will  receive contamination  from the
perusal of what is contained in these pages.
the end. 
INDEX.
Abercrombie, Dr., quoted on intemperate eating, 204 250
Absorbents of the bowels, 153.
Absorption most active before breakfast, 179. Rapid absorption
  of liquids from the stomach, 47, 81, 113, 180.
Acids, in what cases they promote digestion, 103.
Ages, different, require different kinds of food, 227.
Americans intemperate eaters, 202, 260.
Animal food more digestible and nutritious than vegetable,  132
  Cause of its  greater digestibility, 134.  Also more  stimula-
  ting,  135.  Why apparently more binding, 171.  Improper for
  infants, 234.
Anxiety impedes digestion, 263, 265.
Aorta, 162.
Appetite, its necessity as a warning that nutriment  is required.
  25, 26, 198   See Hunger.   Thirst.                 ,
Arrow-root, 120,132.

Beaumont, Dr.,  quoted on Mastication, 59.  His observations
  on the stomach of a patient named St. Martin, quoted, 89  109
  131,  138, 251,  256, 272,  283.  Summary of inferences drawn
  from  his experiments, 140.  Quoted  on the quantity of food
  proper to be eaten, 198.
Bile secreted by the liver, 163.  Account of it, 164.   Not found
  in the stomach during health,  165.  Its presence there facili-
  tates  the digestion of fat and oily food, 253.
Birds, gizzard of granivorous, 57.
Bladder, 162.
Blood circulated in the stomach increased by its action, 80, 255.
  Breathing necessary for the conversion of chyle into blood
  157.   Fulness of blood,  219.
Bloodvessels of the stomach, 79.
Boarding-schools, insufficient food often given there, 224, 246.
Bowels described, 145.  Their different coats—the peritoneal,
  147;  muscular, 149; and mucous, 151.  Action of purgatives
  on the, 149,153.   Contain air, 151.  Their sympathy with the
  skin, 152.  Excretion and absorption of the, 152.   Conditions
  essential  to their  perfect action, 159. Their vermicular or
  peristaltic motion. 149.169.  Why most open when vegetable
                             C c 
302                     INDEX.
  food is used, 171,288.  Their uses, 287; as an outlet of waste
  matter, 287.   Their action bears a relation to the kind of food,
  288.  Causes of their inactivity considered, 291-92.  Natural
  aids to their action, 293.   General neglect of these, 294.  Bad
  health thence arising, 297.  Their regularity important, 298.
Bowel-complaint frequently produced by chill of the skin, 152,
  153, 288.
Brachet, his experiments showing that hunger is an affection of
  the brain, 28.  Quoted on hunger, 33.
Brain the seat of the sensations of hunger and thirst, 27.  Should
  not be overtasked in childhpod, 239.  Influence  of its state
  upon digestion, 263-7.
Breakfast,  proper time for, 178.   Labour  before  it improper
  without refreshment, 181.

Caldwell, Dr., quoted on intemperate eating in America, 202,
  260 ; on the influence of the state of the brain as a source of
  indigestion, 266.
Carnivorous animals have small organs of digestion,/72, 133,
  138.  Their gastric juice, 100.
Cassius, his leanness, as described by Shakspeare, 265.
Cheerfulness promotes digestion, 263.
Chewing, 48.  See Mastication.
Chicken, 253.
Children, great importance of regulating their diet properly, 209.
  Prevalent error of over-feeding them, 1210, 230.  Suffer also
  from deficiency of food, 233,  236.   Animal diet  not  to be
  given them too early, 234.  Impropriety of tasking and confi-
  ning them too much at school, 239.   Dull children often be-
  come talented men, 239.  Whether they ought to be allowed
  wine, 278.
Cholera, loss of the fluid parts  of the body in, 47, 153, 270.
Chyle, 66.  Its composition the same, from  whatever food deri-
  ved; 63-65. Chylification described, 144.  This subject rather
  obscure, 145.  Converted into blood in the lungs, 157.
Chyme, 66.
Clark, Dr., on the great importance of the proper regulation of
  -diet in youth, 236, 237, 245.
Clarke, Adam, a dunce at  school,  240.
Climate ought to modify food, 136.
Coagulation of milk and albumen by gastric juice, 99, 113.
Coecum, 168.
Coffee, 190, 272, 276.
Colon described, 168.
Condiments, 142.
Constitution, food ought to vary according to, 226.  Suscentible
  of being greatly modified by regimen, 247.             *f
Consumption, pulmonary, how productive  of leanness of the 
INDEX.                     303
  body, 158.*  Often the result  of mismanagement of diet in
  childhood, 236, 245.
Costiveness, causes of, 150, 214, 289.  How removable, 293.

Deglutition of food, 60.
Dietetics, principles of, viewed in relation to the laws of diges-
  tion, 173.
Digestion vigorous and rapid in proportion to the quantity of
  nourishment required by the body, 35.   Organs of, described,
  63, et seq.   Its wonderful power of reducing the most opposite
  varieties of food to the same substance, 63.  Nervous energy
  essential to, 02, 258, 285.   Different  theories of,  106.  Is a
  chemico-vital process, 108.  Conditions requisite for it—1. A
  sufficiency of gastric juice, 108; 2.  A temperature  of 98°
  or 100°, 115 ;  and, 3. Gentle agitation of the contents of the
  stomach,  116.  Aided by laughter and cheerfulness, 121,263,
  265.  Ill performed when previous meal remains in stomach,
  124.  Comparative digestibility of different kinds of food, 127.
  Time required for digestion of  the same article different in
  different states of the body, 131.   Animal food more digestible
  than vegetable,  112, 114,  132,  249, 251 ; and why, 134.  A
  proper selection of food not the only requisite of good diges
  tion, 174.  Vigorous in  youth,  243.   Retarded by bodily or
  mental exertion immediately before or after eating, 258.  In-
  tellectual vivacity diminished while digestion  is going  on,
  262.  Influence of the mind upon  digestion, 263, 265.
 Dinner, proper time for, 183.  Late fashionable  dinner-hours,
  ' 188.  Relaxation necessary after dinner, 190.  Drams at, 286.
 Dressmakers, an improvement in the regulation of their estab-
  lishments suggested, 207.
 Drink necessary to supply the waste of the  liquid portions of
  the  body, 46,270.  Bad effects when withheld, 46.  Absorbed
  directly from the stomach into the system, 47, 81, 113, 180.
  Temperature  of drinks  considered, 272.  Water as a drink,
  278.  Wine, 278.  Fermented liquors, 278.   Spirits hurtful,
  2S2.  Sudden changes of its temperature hurtful to the teeth,
  55.  See Liquid.  Thirst.
 Duodenum, 66, 71,160-3.

 Eating ought not  to  be  too rapid, 118, 260.   Times of, 173.
  Eating too much a prolific source of disease, 200, 260.  Con-
  ditions to be observed before and after eating, 255.   See Food.
  Meals.
 Epiglottis, 61.
 Excrement, 167.
 Excretion of waste matter into the bowels, 154, 287
 Exercise renders appetite keen, 33, 35, ct seq.   Prevents cos-
  tiveness.  150. 169, 295. 
304
INDEX.
 Farinaceous food, 132,252, 293.
 Fat and oily food, 166, 249, 253.
 Fermentation and digestion different processes, 107.
 Fever, loss of appetite during it a wise arrangement, 42.
 Fish, 253.
 Fluids.   See Drink.  Liquid.  Thirst.
 Follicles of the stomach, 80.
 Food necessary to supply waste of the substance of living be-
  ings,  20.   Requisite quantity varies according to circum-
  stances, 22, et seq.  Warning given  by hunger when  food is
  required, 25, 26, 33, 198.   Most necessary during growth, 34,
  198 ;  and  when  the life is active, 35, et seq.   Error  of eating
  too much, 36, et seq., 200, 260.  Thirst varies in intensity ac-
  cording to the kind of food, 46.   Mastication, 48 ; insaliva-
  tion, 56 ;  and deglutition  of food, 61.   Its quality modifies the
  amount of saliva secreted, 59.  'The most opposite kinds of
  food reduced by digestion to the same substance, 63.  Differ-
  ent stages through which food passes between its  reception
  into the stomach and its  assimilation, 66.  Size of the stom-
  ach varies according to its quality, 11.  Sudden and extreme
  changes  of  diet injurious,  and why, 101.  Ought not to  be
  rapidly swallowed, 117,  260.  Thoroughly mixed  with the
  gastric juice in the stomach, 119.  Concentrated food, why
  digested with difficulty, 120, 135,289  Ought not to be taken
  till previous meal is digested, 124.   Comparative digestibility
  of different kinds of, 127.   Animal food,  more  digestible
  and nutritious  than  vegetables, 112, 114, 132, 249, 251 ; and
  why,  134.   Farinaceous food,  132, 252, 293.   Soup, 133, 250.
  Injection of food into the  bowels,  155.  Times of eating, 174.
  Quantity to  be eaten, 197.  Bad effects of eating too much,
  204, 250.   Are mixtures  of food hurtful ? 205.  Food of chil-
  dren, 209.   Food of the poor too scanty, 221, 236.  Errors of
  over-feeding and under-feeding children, 210, 223.  Proper
  food of man, 225.  Different kinds of food suitable  in differ-
  ent climates, 136;  for different constitutions, 226; and at dif-
  ferent ages, 227.   See Meals.   Eating.

Gall-bladder, 164.  Gall-stones, 165.
Game, 253.
Gastric juice, 66, 88, 140.  Secreted only when  there is food in
  the stomach, 94.   Its chymical composition, 96.  Acts only
  upon  dead inorganic  substances, 97.  Its power of coagula-
  ting milk and albumen,  99, 113, 212. Its antiseptic quality,
  100, 107.   Adapted in different animals  to the  nature of the
  food, 100.   Modified  in the same  individual according to the
  wants of the system, 102.  On which of its elements does its
  solvent power depend ? 102. The amount secreted always in
  proportion to the quantity of aliment required by the body 
                          INDEX.                     305

   103, 199.  Its secretion retarded by disagreeable mental emo-
   tions and feverishness, 104, 285.  Indispensable to digestion,
   108.  Thoroughly mixed with the food in  the stomach, 119.
   Adaptation of food to its qualities in different individuals, 137.
   Quantity secreted at each meal, 256.
 Gizzard of granivorous birds, 57, 74.
 Grief enfeebles digestion, 121, 263,265.
 Growth, periods of, require an increased supply of food in vege-
   tables, 23; and  animals, 24, 34, 200, 203.
 Gruel, 132.
 Gullet, 61.

 Head, Sir  Francis, quoted on the quantities of cold water drunk
   at the brunnens of Nassau, 180; and on the prejudicial effects
   of intemperate eating, 200.
 Herbivorous animals have large  organs of digestion, 72,133,138.
   Their gastric juice, 100.   The digestion of their food partly
   effected  in the intestines, 1.70.
 Hippocrates, his theory of digestion, 107. ■
 Horse, digestion of the, 170.  Never fed immediately before or
   after a journey, 260.  May sometimes drmk a little though
   perspiring, 273"
 Hufeland quoted on the beneficial influence of laughter in aiding
   digestion, 121.
 Hunger, necessity of the sense of, as a warning that food is re-
   quired; 25, 198.   An affection of the brain, 27.   Allayed by
   narcotics,  29, 30.  Influenced by mental emotions, 30.  By
   what condition of the stomach is it excited? 31.  Felt keenly
   when the  body is in need of  repair, 33, 106.  Sharpened by
   muscular exercise, 33, 35.   Its absence during fever a wise
   arrangement, 42.  Susceptible of being trained, 42.  Error of
   confounding  it with taste, 43.  Morbid cravings  of hunger
   when food is( not required, 44.  Instances of extraordinary
   voracity, 45.
 Hydra, stomach of the, 68-69.

Ices and ice-creams hurtful  after a  meal, 274.  Ice useful in
   warm weather when used  with caution, 275.  Examples  in
   Italy and Virginia, 275.
Ileum, 167.
Indigestion, why prevalent among sedentary persons,  37.   In-
  jures the teeth, 55.  Often beneficial in warding off more se-
  rious diseases, 206, 215.  Caused by grief, anxiety, and over-
  study, 262-7.
Infants, food proper for, as indicated by the state of their teeth,
  53, 228.  Diet of, 209, 227.   Prevalent errors in the treatment
  of, 212.   Proper time for weaning them, 233.
Infection, why most easily caught before breakfast,  178. 
306
INDEX.
Injection of food into the bowels, 155.
Insalivation of food, 56.
Intemperate eating a prevalent cause of disease, 200.   Drink
  ing, 283.

Jejunum, 167.
Jelly, 120.

Lacteals, 67, 154.
Laughter aids digestion, 121, 265.
Laxatives,  150,  153, 214, 290.
Lent, rapid recovery of the sick in Catholic countries dunng it,
  202.
Liquid food, 113,120, 133, 250.  Too hot  injurious, 276.  Dif-
  ferent kinds in use, 278.
Liver, its function, 166.
Londe, Dr., quoted on the diet of infants, 211.
Luncheon,  186.
Lungs, how wasting of the body is produced by their disease,
  158.   See Consumption.
Lymphatics, 155.

Mastication, process of, described, 48.  Its apparatus various in
  different  animals according  to the nature of their food, 56.
  Purpose of, 59.  Bad effects  when mastication is incomplete,
  60, 117.
Meals, at what times and after what  intervals they ought to be
  taken,  174, et seq.   Relaxation  necessary after them, 190.
  Principles on which their times and number ought to be fixed,
  193.  Conduct proper before and  after  meals, 255.   Inapti-
  tude for  bodily and mental exertion after them, 257.  Rest
  and tranquillity then necessary,  257.  See Food.  Eating.
Meconium, 213.
Menstruation ceases during pregnancy and suckling, 233.
Mesenteric glands, 157.
Mesentery, 148.
Mesocolon, 149.
Milk coagulated in  the stomach by the gastric juice, 99, 1)3,
  212.   Digested with ease, 132.  The natural food of infants,.
  209, 228.   Causes of its vitiation in mothers, 232.
Milliners, an  improvement in the management of their estab-
  lishments suggested, 207.
Mind, its influence on  appetite for food, 30.   Deteriorated by
  defective nutrition, 223. Its efficiency depends on the health
  of the body, 240, 248.   Ought to rest during digestion, 262.
  Its influence on digestion, 263, 265.
Mirth promotes digestion, 121,  263, 265.
Mixtures of food, whether prejudicial, 205. 
INDEX.
307
   Montegre's opinion of the use of the saliva, 60, 98.
   Morning, exposure before breakfast often dangerous, 178.  Vig-
    our of the system then least, 182.
   Mortality of children, 209.   Mprtality greatest among the poor,

   Mothers  generally ignorant of the  rational  mode  of treating
    children, 209, 235.  Their duties in relation to suckling, 231.
   Mucous or villous coat of the stomach, 78 ; and  intestines, 151.
   Muscular coat of the stomach, 76 ;"  and  intestines, 149.  Mus-
    cular exercise.  See Exercise.
   Mutilation of animals, unsatisfactory nature  of experiments so
    made, 84.

   Napoleon not a bright schoolboy, 240.
   Narcotics allay hunger, 29, 30.
   Nerves of the stomach, 82.
   Nervous energy essential to digestion, 85, 258, 262.
   Newton, Sir Isaac, a dull schoolboy, 240.
   Nursing of children, 212, et seq., 228. Nurses ought not to be
    over-fed, 232.
   Nutrition required to repair waste of substance in living beings,
    20.  See Food.

   CEsophagus, 61.
   Opium allays hunger, 30.

   Pancreas, 66, 166.
   Paris, Dr., an opinion of his controverted, 136.
   Pastry indigestible, 253.
   Peristaltic motion of the bowels, 149, 169, 296.
   Peritoneum, 76, 147.
   Philip, Dr. Wilson, an opinion of his controverted, 122.
   Pneumogastric nerve, 83.
  Poor have larger stomachs  than the rich, 71.  Their food too
A scanty and innutritious, 221, 236.  Their minds thereby de-
r  teriorated. 223.
  Precocity of talent little to be desired, 239.
  Purgatives, their mode of action,  150, 153.  Not required by
    nature, 214, 289.   When improper, 291.
  Putrefaction, digestion different from, 107.
  Pylorus, 71.  Allows only digested  food to issue from the stom-
    ach, 126.

  Quantity of food proper to be eaten, 197.

  Rapid eating improper, 117,  260.
  Respiration, use of, 67.  Digestion aided  by, 121,169.   Neces-
    sary for the conversion of chyle into blood,  158. 
308                     INDEX.
Rice, 132,252.
Roget, Dr., quoted on nutrition, 38 ;  on varieties of food, 64.
Rumination of animals, 50, 57, 74.   Stomach of ruminants de-
  scribed, 72.

Sago, 132, 252.
Saliva, secretion and purpose of, 56, 57.   Its amount  greatest
  when food spicy, 59.  Different in quality from gastric juice,
  98.
Salt meat, how productive of thirst,  46.
Sanguification, 67, 157.
Satiety, 199.
Schools, children too much confined and  tasked  in, 239.   See
  Boarding Schools.
Scrofula frequently the result of a penurious diet, 236; also of
  too exciting food, 245.
Sedentary habits, how productive of indigestion,  37 ; and,cos-
  tiveness, 150, 169, 297.  Less food  required by sedentary than
  by active persons, 205.
Sheridan a dunce, at school, 240.
Siesta, 261.                                             ,
Skin, its sympathy with the bowels,  152, 288.
Soldiers, private, why inferior in strength and health to officers,
  223.   Ought not to eat immediately after a march, 259.
Soup, digestion of, 113, 120, 133, 250.
Spirits, their indiscriminate use hurtful, 280.
Spittle, 56.  See Saliva.
Spleen,  163.
St.  Martin. Alexis, remarkable case of, 89.  See Beaumont.
Stomach, peculiar to animals, 22.  By what state of it is hunger
  excited? 31.  Its sympathy with the rest of the body, 32, et
  seq.  Described, 68, et seq.  Stomach in  the lowest  class of
  animals, 68.  In man, 69.  Various in size, according to qual-
  ity of food, 71.  Stomach of ruminating animals described, 72.
  Coats of the stomach—external, 75; muscular, 75 ; and mu-A-
  cous or villous, 78.  Its muscular action, 76.  Its bloodvessels™
  and follicles, 79, 80.  Its sanguineous circulation increased du-
  ring digestion, 81,256. Its power of absorbing  fluids, 47, 81,
  113,180. Its nerves, 82.  Contracts when each morsel is intro-
  duced, 118.  Its motion during digestion,  121.   Is its  temper-
  ature  then increased ? 138.  Contains no bile in the healthy
  state, 165.   Training of the, 176.  Numerous diseases unjust-
  'y laid to its charge, 217.
Supper, in what cases proper, 192.
Swallowing, process of, 60.
Tartar on the teeth^53.
Tasso, his genius precocious, 240. 
INDEX.
309  .
Taste, error of confounding it with appetite, 43.  Its gratifica-
  tion proper, 58.
Tea, 190, 272, 276.
Teeth described, 49.  Modified in different animals to suit then-
  habits of life, 50.   Milk-teeth, 52.  Changes of the condition
  of the teeth indicate the propriety of certain kinds of diet, 53,
  228, 238.  Necessity of keeping them clean, 54.  Impaired
  by indigestion, 54.  Sudden changes of temperature hurtful
  to them, 55.
Temperaments, different, require different kinds and  quantities
  of food, 225.   May be greatly modified by regimen, 248.
Temperance in eating may be carried too far, 224. In drinking,
  282.
Temperature necessary for digestion, 115.  Whether that of
  the stomach is thereby increased,  138.  That of drinks con-
  sidered, 272.
Thinking, intense, impedes digestion, 262.
Thirst necessary as a  warning  when  drink is  required  by  the
  system, 25, 47, 269.   Nature of, 27, 45  Greatest when body
  in need of liquid nourishment, 46.  Varies in intensity accord-
  ing to nature of the food, 46.  Consequences of its craving not
  being gratified, 47.   See Drink.
Thoracic duct, 67,  157.
Time in which the digestion of an article is effected varies with
  circumstances, 130, 143.  Times of eating,  173.
Tobacco allays hunger, 30.
Tooth-powders,  53.
Travelling before breakfast  frequently improper,  181.  Diet in
  travelling, 196.
Trituration, digestion not effected by, 107.

Vegetables, continual waste of  their substance, 19.  How re-
  paired, 20.  Quantity of nourishment  requisite for them varies
  with circumstances, 22.  Principle  of forcing their growth,
  23.
Vegetable food less digestible than animal,  112, 114, 132, 249,
  251 ; and why, 134.   Also less nutritious, 132.  Its digestion
  effected  to some extent in  the intestines, 171. Why more
  laxative than animal food, 171, 288.
Venison, 253.
Vermicular motion  of the bowels, 149,  169,  296.
Villous or mucous coat of the stomach, 78 ; and bowels,  151.
Vomiting, inverted action of the gullet in, 62.  Vomiting of bile,
  165.
Voracity, remarkable instances of, 44.

Waste universally the attendant of action, 17. Food the means 
310                    INDEX.
  of repairing it in living beings, 20.   See Food.   Waste mat-
  ter excreted into the bowels, 152, 287.
Water safe as a drink, 278.  Cold spring-water dangerous when
  person overheated, 275.  Effects of on stomach, 272.
Water-brash, 80.
Weaning of infants, proper time for, 233.
Wine, how productive of thirst, 46.  Circumstances in which
  its use is proper and improper, 278.
Worms in the bowels, 153.

Youth, period, of transition  from youth to manhood a critical
  season, 208.  Diseases of  the stomach and bowels why then
  common, 297.
THE END. 
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