_Demonstration of food tube of man_ (manikin).--Comparison
with food tube of frog. Drawing (comparative) of food tube
and digestive glands of frog and man.
_Demonstration of simple gland._--(Microscopic preparation.)
_Home experiment and laboratory demonstration._--The
digestion of starch by saliva. Conditions favorable and
unfavorable.
_Demonstration experiment._--The digestion of proteins with
artificial gastric juice. Conditions favorable and
unfavorable.
_Demonstration._--An emulsion as seen under the compound
microscope.
_Demonstration._--Emulsification of fats with artificial
pancreatic fluid. Digestion of starch and protein with
artificial pancreatic fluid.
_Demonstration_ of "tripe" to show increase of surface of
digestive tube.
_Laboratory or home exercise._--Make a table showing the
changes produced upon food substances by each digestive
fluid, the reaction (acid or alkaline) of the fluid, when
the fluid acts, and what results from its action.
Purpose of Digestion.--We have learned that starch and protein food of
plants are formed in the leaves. A plant, however, is unable to make use of
the food in this condition. Before it can be transported from one part of
the plant body to another, it is changed into a soluble form. In this state
it can be passed from cell to cell by the process of osmosis. Much the same
condition exists in animals. In order that food may be of use to man, it
must be changed into a state that will allow of its passage in a soluble
form through the walls of the alimentary canal, or food tube. This is done
by the enzymes which cause digestion. It will be the purpose of this
chapter to discover where and how digestion takes place in our own body.
Alimentary Canal.--In all vertebrate animals, including man, food is taken
in the mouth and passed through a _food tube_ in which it is digested. This
tube is composed of different portions, named, respectively, as we pass
from the _mouth_ downward, the _gullet_, _stomach_, _small_ and _large
intestine_, and _rectum_.
[Illustration: The digestive tract of the frog and man. _Gul_, gullet; _S_,
stomach; _L_, liver; _G_, gall bladder; _P_, pancreas; _Sp_, spleen; _SI_,
small intestine; _LI_, large intestine; _V_, appendix; _A_, anus.]
Comparison of Food Tube of a Frog and Man.--If we compare the food tube of
a dissected frog with the food tube of man (as shown by a manikin or
chart), we find part for part they are much the same. But we notice that
the intestines of man, both small and large, are relatively longer than in
the frog. We also notice in man the body cavity or space in which the
internal organs rest is divided in two parts by a wall of muscle, the
_diaphragm_, which separates the heart and lungs from the other internal
organs. In the frog no muscular diaphragm exists. In the frog we can see
plainly the silvery transparent _mesentery_ or double fold of the lining of
the body cavity in which the organs of digestion are suspended. Numerous
blood vessels can be found especially in the walls of the food tube.
Glands.--In addition to the alimentary canal proper, we find a number of
_digestive glands_, varying in size and position, connected with the canal.
[Illustration: Diagram of a gland. _i_, the common tube which carries off
the secretions formed in the cells lining the cavity _c_; _a_, arteries
carrying blood to the glands; _v_, veins taking blood away from the
glands.]
What a Gland Does. Enzymes.--In man there are the saliva gland of the
mouth, the gastric glands of the stomach, the pancreas and liver, the two
latter connected with the small intestine, and the intestinal glands in the
walls of the intestine. Besides glands which aid in digestion there are
several others of which we will speak later. As we have already learned, a
gland is a collection of cells which takes up material from within the body
and manufactures from it something which is later poured out as a
secretion. An example of a gland in plants is found in the nectar-secreting
cells of a flower.
Certain substances, called _enzymes_, formed by glands cause the digestion
of food. The enzymes secreted by the cells of the glands and poured out
into the food tube act upon insoluble foods so as to change them to a
soluble form. They are the product of the activity of the cell, although
they are not themselves alive. We do not know much about enzymes
themselves, but we can observe what they do. Some enzymes render soluble
different foods, others work in the blood, still others probably act within
any cell of the body as an aid to oxidation, when work is done. Enzymes are
very sensitive to changes in temperature and to the degree of _acidity_ or
_alkalinity_[42] of the material in which they act. We will find that the
enzymes found in glands in the mouth will not act long in the stomach
because of the change from an alkaline surrounding in the mouth to that of
an acid in the stomach. Enzymes seem to be able to work indefinitely,
providing the surroundings are favorable. A small amount of digestive
fluid, if it had long enough to work, could therefore digest an indefinite
amount of food.
Footnote 42: The teacher should explain the meaning of these
terms.
Gland Structure.--The entire inner surface of the food tube is covered with
a soft lining of _mucous membrane_. This is always moist because certain
cells, called _mucus cells_, empty out their contents into the food tube,
thus lubricating its inner surface. When a large number of cells which have
the power to secrete fluids are collected together, the surface of the food
tube may become indented at this point to form a pitlike _gland_. Often
such depressions are branched, thus giving a greater secreting surface, as
is seen in the figure on page 298. The cells of the gland are always
supplied with blood vessels and nerves, for the secretions of the glands
are under the control of the nervous system.
How a Gland Secretes.--We must therefore imagine that as the blood goes to
the cells of a gland it there loses some substances which the gland cells
take out and make over into the particular enzyme that they are called upon
to manufacture. Under certain conditions, such as the sight or smell of
food, or even the desire for it, the activity of the gland is stimulated.
It then pours out its secretion containing the digestive enzyme. Thus a
gland does its work.
Salivary Glands.--We are all familiar with the substance called _saliva_
which acts as a lubricant in the mouth. Saliva is manufactured in the cells
of three pairs of glands which empty into the mouth, and which are called,
according to their position, the _parotid_ (beside the ear), the
_submaxillary_ (under the jawbone), and the _sublingual_ (under the
tongue).
[Illustration: Experiment showing non-osmosis of starch in tube _A_, and
osmosis of sugar in tube _B_.]
Digestion of Starch.--If we collect some saliva in a test tube, add to it a
little starch paste, place the tube containing the mixture for a few
minutes in tepid water, and then test with Fehling's solution, we shall
find grape sugar present. Careful tests of the starch paste and of the
saliva made separately will usually show no grape sugar in either.
If another test be made for grape sugar, in a test tube containing starch
paste, saliva, and a few drops of any weak acid, the starch will be found
not to have changed. The digestion or change of starch to grape sugar is
caused by the presence in the saliva of an _enzyme_, or _digestive
ferment_. You will remember that starch in the growing corn grain was
changed to grape sugar by an enzyme called _diastase_. Here a similar
action is caused by an enzyme called _ptyalin_. This ferment acts _only_ in
an alkaline medium at about the temperature of the body.
[Illustration: The mouth cavity of man. _e_, Eustachian tube; _hp_, hard
palate; _sp_, soft palate; _ut_, upper teeth; _bc_, buccal cavity; _lt_,
lower teeth; _t_, tongue; _ph_, pharynx; _ep_, epiglottis; _lx_, voice box;
_oe_, gullet; _tr_, trachea.]
Mouth Cavity in Man.--In our study of a frog we find that the mouth cavity
has two unpaired and four paired tubes leading from it. These are (_a_) the
_gullet_ or food tube, (_b_) the _windpipe_ (in the frog opening through
the _glottis_), (_c_) the paired nostril holes (_posterior nares_), (_d_)
the paired _Eustachian tubes_, leading to the ear. All of these openings
are found in man.
In man the mouth cavity, and all internal surfaces of the food tube, are
lined with a _mucous membrane_. The _mucus_ secreted from gland cells in
this lining makes a slippery surface so that the food may slip down easily.
The roof of the mouth is formed in front by a plate of bone called the
_hard palate_, and a softer continuation to the back of the mouth, the
_soft palate_. These separate the nose cavity from that of the mouth
proper. The part of the space back of the soft palate is called the
_pharynx_, or throat cavity. From the pharynx lead off the _gullet_ and
_windpipe_, the former back of the latter. The lower part of the mouth
cavity is occupied by a muscular tongue. Examination of its surface with a
looking-glass shows it to be almost covered in places by tiny projections
called _papillae_. These papillae contain organs known as _taste buds_, the
sensory endings of which determine the taste of substances. The tongue is
used in moving food about in the mouth, and in starting it on its way to
the gullet; it also plays an important part in speaking.
[Illustration: I. Teeth of the upper jaw, from below. _1, 2_, incisors;
_3_, canine; _4, 5_, premolars; _6, 7, 8_, molars. II. longitudinal section
of a tooth. _E_, enamel; _D_, dentine; _C_, cement; _P_, pulp cavity.]
The Teeth.--In man the teeth, unlike those of the frog, are used in the
mechanical preparation of the food for digestion. Instead of holding prey,
they crush, grind, or tear food so that more surface may be given for the
action of the digestive fluids. The teeth of man are divided, according to
their functions, into four groups. In the center of both the upper and
lower jaw in front are found eight teeth with chisel-like edges, four in
each jaw; these are the _incisors_, or cutting teeth. Next is found a
single tooth on each side (four in all); these have rather sharp points and
are called the _canines_. Then come two teeth on each side, eight in all,
called _premolars_. Lastly, the _flat-top molars_, or grinding teeth, of
which there are six in each jaw. Food is caught between irregular
projections on the surface of the molars and crushed to a pulpy mass.
Hygiene of the Mouth.--Food should simply be chewed and relished, with no
thought of swallowing. There should be no more effort to prevent than to
force swallowing. It will be found that if you attend only to the agreeable
task of extracting the flavors of your food, Nature will take care of the
swallowing, and this will become, like breathing, involuntary. The instinct
by which most people eat is perverted through the "hurry habit" and the use
of abnormal foods. Thorough mastication takes time, and therefore one must
not feel hurried at meals if the best results are to be secured. The
stopping point for eating should be at the _earliest_ moment after one is
really satisfied.
Care of the Teeth.--It has been recently found that fruit acids are very
beneficial to the teeth. Vinegar diluted to about half strength with water
makes an excellent dental wash. Clean your teeth carefully each morning and
before going to bed. Use dental silk after meals. We must remember that the
bacteria which cause decay of the teeth are washed down into the stomach
and may do even more harm there than in the mouth.
How Food is Swallowed.--After food has been chewed and mixed with saliva,
it is rolled into little balls and pushed by the tongue into such position
that the muscles of the throat cavity may seize it and force it downward.
Food, in order to reach the gullet from the mouth cavity, must pass over
the opening into the windpipe. When food is in the course of being
swallowed, the upper part of this tube forms a trapdoor over the opening.
When this trapdoor is not closed, and food "goes down the wrong way," we
choke, and the food is expelled by coughing.
[Illustration: Peristaltic waves on the gullet of man. (A bolus means
little ball.)]
The Gullet, or Esophagus.--Like the rest of the food tube the gullet is
lined by soft and moist mucous membrane. The wall is made up of two sets of
muscles,--the inside ones running around the tube; the outer layer of
muscle taking a longitudinal course. After food leaves the mouth cavity, it
gets beyond our direct control, and the muscles of the gullet, stimulated
to activity by the presence of food in the tube, push the food down to the
stomach by a series of contractions until it reaches the stomach. These
wavelike movements (called _peristaltic_ movements) are characteristic of
other parts of the food tube, food being pushed along in the stomach and
the small intestine by a series of slow-moving muscular waves. Peristaltic
movement is caused by muscles which are not under voluntary nervous
control, although anger, fear, or other unpleasant emotions have the effect
of slowing them up or even stopping them entirely.
Stomach of Man.--The stomach is a pear-shaped organ capable of holding
about three pints. The end opposite to the gullet, which empties into the
small intestine, is provided with a ring of muscle forming a valve called
the _pylorus_. There is also another ring of muscle guarding the entrance
to the stomach.
Gastric Glands.--If we open the stomach of the frog, and remove its
contents by carefully washing, its wall is seen to be thrown into folds
internally. Between the folds in the stomach of man, as well as in the
frog, are located a number of tiny pits. These form the mouths of the
_gastric glands_, which pour into the stomach a secretion known as the
_gastric juice_. The gastric glands are little tubes, the lining of which
secretes the fluid. When we think of or see appetizing food, this secretion
is given out in considerable quantity. The stomach, like the mouth,
"waters" at the sight of food. Gastric juice is slightly acid in its
chemical reaction, containing about .2 per cent free _hydrochloric acid_.
It also contains two very important enzymes, one called _pepsin_, and
another less important one called _rennin_.
Action of Gastric Juice.--If protein is treated with artificial gastric
juice at the temperature of the body, it will be found to become swollen
and then gradually to change to a substance which is soluble in water. This
is like the action of the gastric juice upon proteins in the stomach.
The other enzyme of gastric juice, called _rennin_, curdles or coagulates a
protein found in milk; after the milk is curdled, the pepsin is able to act
upon it. "Junket" tablets, which contain rennin, are used in the kitchen to
cause this change.
[Illustration: A peptic gland, from the stomach, very much magnified. _A_,
central or chief cell, which makes pepsin; _B_, border cells, which make
acid. (From Miller's _Histology_.)]
The hydrochloric acid found in the gastric juice acts upon lime and some
other salts taken into the stomach with food, changing them so that they
may pass into the blood and eventually form the mineral part of bone or
other tissue. The acid also has a decided antiseptic influence in
preventing growth of bacteria which cause decay, and some of which might
cause disease.
Movement of Walls of Stomach.--The stomach walls, provided with three
layers of muscle which run in an oblique, circular, and longitudinal
direction (taken from the inside outward), are well fitted for the constant
churning of the food in that organ. Here, as elsewhere in the digestive
tract, the muscles are involuntary, muscular action being under the control
of the so-called _sympathetic nervous system_. Food material in the stomach
makes several complete circuits during the process of digestion in that
organ. Contrary to common belief, the greatest amount of food is digested
_after_ it leaves the stomach. But this organ keeps the food in it in
almost constant motion for a considerable time, a meal of meat and
vegetables remaining in the stomach for three or four hours. While movement
is taking place, the gastric juice acts upon proteins, softening them,
while the constant churning movement tends to separate the bits of food
into finer particles. Ultimately the semifluid food, much of it still
undigested, is allowed to pass in small amounts through the pyloric valve,
into the small intestine. This is allowed by the relaxation of the ringlike
muscles of the pylorus.
Experiments on Digestion in the Stomach.--Some very interesting experiments
have recently been made by Professor Cannon of Harvard with reference to
movements of the stomach contents. Cats were fed with material having in it
bismuth, a harmless chemical that would be visible under the X-ray. It was
found that shortly after food reached the stomach a series of waves began
which sent the food toward the pyloric end of the stomach. If the cat was
feeling happy and well, these contractions continued regularly, but if the
cat was cross or bad tempered, the movements would stop. This shows the
importance of _cheerfulness_ at meals. Other experiments showed that food
which was churned into a soft mass was only permitted to leave the stomach
when it became thoroughly permeated by the gastric juice. It is the _acid_
in the partly digested food that causes the stomach valve to open and allow
its contents to escape little by little into the small intestine.
The partly digested food in the small intestine almost immediately comes in
contact with fluids from two glands, the liver and pancreas. We shall first
consider the function of the pancreas.
Position and Structure of the Pancreas.--The most important digestive gland
in the human body is the pancreas. The gland is a rather diffuse structure;
its duct empties by a common opening with the bile duct into the small
intestine, a short distance below the pylorus. In internal structure, the
pancreas resembles the salivary glands.
[Illustration: Appearance of milk under the microscope, showing the natural
grouping of the fat globules. In the circle a single group is highly
magnified. Milk is one form of an emulsion. (S. M. Babcock, Wis. Bul. No.
61.)]
Work done by the Pancreas.--Starch paste added to artificial pancreatic
fluid and kept at blood heat is soon changed to sugar. Protein, under the
same conditions, is changed to a peptone. Fats, which so far have been
unchanged except to be melted by the heat of the body, are changed by the
action of the pancreas into a form which can pass through the walls of the
food tube. If we test pancreatic fluid, we find it strongly _alkaline_ in
its reaction. If two test tubes, one containing olive oil and water, the
other olive oil and a weak solution of caustic soda, an _alkali_, be shaken
violently and then allowed to stand, the oil and water will quickly
separate, while the oil, caustic soda, and water will remain for some time
in a milky _emulsion_. If this emulsion be examined under the microscope,
it will be found to be made of millions of little droplets of fat, floating
in the liquid. The presence of the caustic soda helped the forming of the
emulsion. Pancreatic fluid similarly emulsifies fats and changes them into
soft soaps and fatty acids. Fat in this form may be absorbed. The process
of this transformation is not well understood.
Conditions under which the Pancreas does its Work.--The secretion from this
gland seems to be influenced by the overflow of acid material from the
stomach. This acid, on striking the lining of the small intestine, causes
the formation in its walls of a substance known as _secretin_. This
secretin reaches the blood and seems to stimulate all the glands pouring
fluid into the intestine to do more work. A pint or more of pancreatic
fluid is secreted every day.
The Intestinal Fluid.--Three different pancreatic enzymes do the work of
digestion, one acting on starch, another on protein, and a third on fats.
It has been found that some of these enzymes will not do their work unless
aided by the _intestinal_ fluid, a secretion formed in glands in the walls
of the small intestine. This fluid, though not much is known about it, is
believed to play an important part in the digestion of all kinds of foods
left undigested in the small intestine.
Liver.--The liver is the largest gland in the body. In man, it hangs just
below the diaphragm, a little to the right side of the body. During life,
its color is deep red. It is divided into three lobes, between two of which
is found the _gall bladder_, a thin-walled sac which holds the _bile_, a
secretion of the liver. Bile is a strongly alkaline fluid of greenish
color. It reaches the intestine through the same opening as the pancreatic
fluid. Almost one quart of bile is passed daily into the digestive canal.
The color of bile is due to certain waste substances which come from the
destruction of worn-out red corpuscles of the blood. This destruction takes
place in the liver.
[Illustration: Diagram of a bit of the wall of the small intestine, greatly
magnified, _a_, mouths of intestinal glands; _b_, villus cut lengthwise to
show blood vessels and lacteal (in center); _e_, lacteal sending branches
to other villi; _i_, intestinal glands; _m_, artery; _v_, vein; _l_, _t_,
muscular coats of intestine wall.]
Functions of Bile.--The action of bile is not very well known. It has the
very important faculty of aiding the pancreatic fluid in digestion, though
alone it has slight if any digestive power. Certain substances in the bile
aid especially in the absorption of fats. Bile seems to be mostly a waste
product from the blood and as such incidentally serves to keep the contents
of the intestine in a more or less soft condition, thus preventing extreme
constipation.
The Liver a Storehouse.--Perhaps the most important function of the liver
is the formation within it of a material called _glycogen_, or animal
starch. The liver is supplied by blood from two sources. The greater amount
of blood received by the liver comes directly from the walls of the stomach
and intestine to this organ. It normally contains about one fifth of all
the blood in the body. This blood is very rich in food materials, and from
it the cells of the liver take out sugars to form glycogen.[43] Glycogen is
stored in the liver until such a time as a food is needed that can be
quickly oxidized; then it is changed to sugar and carried off by the blood
to the tissue which requires it, and there used for this purpose. Glycogen
is also stored in the muscles, where it is oxidized to release energy when
the muscles are exercised.
Footnote 43: It is known that glycogen _may_ be formed in
the body from protein, and possibly from fatty foods.
The Absorption of Digested Food into the Blood.--The object of digestion is
to change foods from an insoluble to a soluble form. This has been seen in
the study of the action of the various digestive fluids in the body, each
of which is seen to aid in dissolving solid foods, changing them to a
fluid, and, in case of the bile, actually assisting them to pass through
the wall of the intestine. A small amount of digested food may be absorbed
by the blood in the blood vessels of the walls of the stomach. Most of the
absorption, however, takes place through the walls of the small intestine.
Structure of the Small Intestine.--The small intestine in man is a slender
tube nearly twenty feet in length and about one inch in diameter. If the
chief function of the small intestine is that of absorption, we must look
for adaptations which increase the absorbing surface of the tube. This is
gained in part by the inner surface of the tube being thrown into
transverse folds which not only retard the rapidity with which food passes
down the intestine, but also give more absorbing surface. But far more
important for absorption are millions of little projections which cover the
inner surface of the small intestine.
The Villi.--So numerous are these projections that the whole surface
presents a velvety appearance. Collectively, these structures are called
the _villi_ (singular _villus_). They form the chief organs of absorption
in the intestine, several thousand being distributed over every square inch
of surface. By means of the folds and villi the small intestine is
estimated to have an absorbing surface equal to twice that of the surface
of the body. Between the villi are found the openings of the _intestinal
glands_.
Internal Structure of a Villus.--The internal structure of a villus is best
seen in a longitudinal section. We find the outer wall made up of a thin
layer of cells, the _epithelial_ layer. It is the duty of these cells to
absorb the semifluid food from within the intestine. Underneath these cells
lies a network of very tiny blood vessels, while inside of these, occupying
the core of the villus, are found spaces which, because of their white
appearance after absorption of fats, have been called _lacteals_. (See
figure, page 307.)
[Illustration: Diagram to show how the nutrients reach the blood.]
Absorption of Foods.--Let us now attempt to find out exactly how foods are
passed from the intestines into the blood. Food substances in solution may
be soaked up as a sponge would take up water, or they may pass by osmosis
into the cells lining the villus. These cells break down the peptones into
a substance that will pass into and become part of the blood. Once within
the villus, the sugars and digested proteins pass through tiny blood
vessels into the larger vessels comprising the _portal circulation_. These
pass through the liver, where, as we have seen, sugar is taken from the
blood and stored as glycogen. From the liver, the food within the blood is
sent to the heart, from there is pumped to the lungs, from there returns to
the heart, and is pumped to the tissues of the body. A large amount of
water and some salts are also absorbed through the walls of the stomach and
intestine as the food passes on its course. The fats in the form of soaps
and fatty acids pass into the space in the center of the villus. Later they
are changed into fats again, probably in certain groups of gland cells
known as _mesenteric_ glands, and eventually reach the blood by way of the
thoracic duct without passing through the liver.
Large Intestine.--The large intestine has somewhat the same structure as
the small intestine, except that it lacks the villi and has a greater
diameter. Considerable absorption, however, takes place through its walls
as the mass of food and refuse material is slowly pushed along by the
muscles within its walls.
Vermiform Appendix.--At the point where the small intestine widens to form
the large intestine, a baglike pouch is formed. From one side of this pouch
is given off a small tube about four inches long, closed at the lower end.
This tube, the rudiment of what is an important part of the food tube in
the lower vertebrates, is called the _vermiform appendix_. It has come to
have unpleasant notoriety in late years, as the site of serious
inflammation.
Constipation.--In the large intestine live millions of bacteria, some of
which make and give off poisonous substances known as toxins. These
substances are easily absorbed through the walls of the large intestine,
and, when they pass into the blood, cause headaches or sometimes serious
trouble. Hence it follows that the lower bowel should be emptied of this
matter as frequently as possible, at least once a day. Constipation is one
of the most serious evils the American people have to deal with, and it is
largely brought about by the artificial life which we lead, with its lack
of exercise, fresh air, and sleep. Fruit with meals, especially at
breakfast, plenty of water between meals and before breakfast, exercise,
particularly of the abdominal muscles, and regular habits will all help to
correct this evil.
Hygienic Habits of Eating; the Causes and Prevention of Dyspepsia.--From
the contents of the foregoing chapter it is evident that the object of the
process of digestion is to break up solid food so that it may be absorbed
to form part of the blood. Any habits we may form of thoroughly chewing our
food will evidently aid in this process. Undoubtedly much of the distress
known as dyspepsia is due to too hasty meals with consequent lack of proper
mastication of food. The message of Mr. Horace Fletcher in bringing before
us the need of proper mastication of food and the attendant evils of
overeating is one which we cannot afford to ignore. It is a good rule to go
away from the table feeling a little hungry. Eating too much overtaxes the
digestive organs and prevents their working to the best advantage. Still
another cause of dyspepsia is eating when in a _fatigued_ condition. It is
always a good plan to rest a short time before eating, especially after any
hard manual work. We have seen how great a part unpleasant emotions play in
preventing peristaltic movements of the food tube. Conversely, pleasant
conversation, laughter, and fun will help you to digest your meal. Eating
between meals is condemned by physicians because it calls the blood to the
digestive organs at a time when it should be more active in other parts of
the body.
Effect of Alcohol on Digestion.--It is a well-known fact that alcohol
extracts water from tissues with which it is in contact. This fact works
much harm to the interior surface of the food tube, especially the walls of
the stomach, which in the case of a hard drinker are likely to become
irritated and much toughened. In very small amounts alcohol stimulates the
secretion of the salivary and gastric glands, and thus appears to aid in
digestion.
The following results of experiments on dogs, published in the _American
Journal of Physiology_, Vol. I, Professor Chittenden of Yale University
gives as "strictly comparable," because "they were carried out in
succession on the same day." They show that alcohol retards rather than
aids in digestion:--
==========================================================================
NUMBER OF EXPERIMENT |1/16 LB. MEAT WITH WATER| 1/16 LB. MEAT WITH
| | DILUTE ALCOHOL
------------------------+------------------------+------------------------
XVII [alpha] 9:15 A.M. | Digested in 3 hours |
XVII [beta] 3:00 P.M. | | Digested in 3:15 hours
XVIII [alpha] 8:30 A.M. | Digested in 2:30 hours |
XVIII [beta] 2:10 P.M. | | Digested in 3:00 hours
XIX [alpha] 9:00 A.M. | Digested in 2:30 hours |
XIX [beta] 2:30 P.M. | | Digested in 3:00 hours
XX [alpha] 9:15 A.M. | | Digested in 2:45 hours
XX [beta] 2:30 P.M. | Digested in 2:15 hours |
VI [alpha] 9:15 A.M. | | Digested in 3:45 hours
VI [beta] 1:00 P.M. | Digested in 3:15 hours |
------------------------+------------------------+------------------------
Average | 2:42 hours | 3:09 hours
------------------------+------------------------+------------------------
As a result of his experiments, Professor Chittenden remarks: "We believe
that the results obtained justify the conclusion that gastric digestion as
a whole is not materially modified by the introduction of alcoholic fluids
with the food. In other words, the unquestionable acceleration of gastric
secretion which follows the ingestion of alcoholic beverages is, as a rule,
counterbalanced by the inhibitory effect of the alcoholic fluids upon the
chemical process of gastric digestion, with perhaps at times a tendency
towards preponderance of inhibitory action." Others have come to the same
or stronger conclusions as to the undesirable action of alcohol on
digestion, as a result of their own experiments.
Effect of Alcohol on the Liver.--The effect of heavy drinking upon the
liver is graphically shown in the following table prepared by the
Scientific Temperance Federation of Boston, Mass.:--
[Illustration: Proportion of deaths from disease in a certain area due to
alcohol. The black area shows deaths due to alcohol.[44]]
Footnote 44: Does not include deaths from general alcoholic
paralysis or other organic diseases due to alcohol. Liver
cirrhosis due to alcohol conservatively estimated at 75 per
cent of total cases.
"Alcoholic indulgence stands almost if not altogether in the
front rank of the enemies to be combated in the battle for
health."--PROFESSOR WILLIAM T. SEDGWICK.