shaped pouch or bag with an opening into the duodenum,
and from thence into the larger intestine. From the mouth
to the end of this intestine, the whole may be called the
alimentary canal ; a tube of varying size and some thirty-
six feet in length. The mouth must be considered part of
it, as it is in the mouth that digestion actually begins ;
all starchy foods depending upon the action of the saliva
for genuine digestion, saliva having some strange power
b}^ which starch is converted into sugar. Swallowed
whole, or placed directly in the stomach, such food passes
through the body unchanged. Each division of the ali-
mentar}^ canal has its own distinct digestive juice, and I
give them in the order in which they occur.
Fu'st, The saliva; secreted from the glands of the
mouth : — alkaline, glairy, adhesive.
Second, The gastric juice ; secreted in the inner or third
lining of the stomach, — an acid, and powerful enough to
dissolve all the fiber and albumen of flesh food.
Third, The pancreatic juice ; secreted by the pancreas,
which you know in animals as sweetbreads. This juice
has a peculiar influence upon fats, which remain unchanged
by saliva and gastric juice ; and not until dissolved by
pancreatic juice, and made into what chemists call an
emulsion, can they be absorbed into the s^^stem.
Fourth, The bile ; which no physiologist as yet thor-
oughly understands. We know its action, but hardly why
it acts. It is a necessity, however ; for if by disease the
supply be cut off, an animal emaciates and soon dies.
Fifth, The intestinal juice ; which has some properties
like saliva, and is the last product of the digestive forces.
A meal, then, in its passage downward is first diluted
and increased in bulk by a watery fluid which prepares all
THE BODY AND ITS COMPOSITION. 65
the starchy portion for absorption. Then conies a still
more profuse fluid, dissolving all the meaty part. Then
the fat is attended to by the stream of pancreatic juice,
and at the same time the bile pours upon it, doing its own
work in its own mysterious way ; and last of all, lest any
process should have been imperfect, the long canal sends
out a juice having some of the properties of all.
Thus each day's requirements call for
PINTS.
Of saliva .Sf
gastric juice 12
bile 3|
pancreatic juice li
intestinal juice ^
2li
Do not fancy this is all wasted or lost. Very far from
it : for the whole process seems to be a second circulation,
as it were ; and, while the blood is moving in its wonderful
passage through veins and arteries, another circulation as
wonderful, an endless current going its unceasing round
so long as life lasts, is also taking place. But without
food the first would become impossible ; and the quality of
food, and its proper digestion, mean good or bad blood as
the case may be. We must follow our mouthful of food,
and see how this action takes place.
When the different juices have all done their work, the
chyme i which is food as it passes from the stomach into
the duodenum or passage to the lower stomach or bowels,
becomes a milk}^ substance called cJiyle, which moves
slowly, pushed by numberless muscles along the bowel,
which squeeze much of it into little glands at the back of
the bowels. These are called the mesenteric glands ; and,
5
66 THE BODY AND ITS COMPOSITION.
Page 32
Presented as published in 1881. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
shaped pouch or bag with an opening into the duodenum, and from thence into the larger intestine. From the mouth to the end of this intestine, the whole may be called the alimentary canal ; a tube of varying size and some thirtysix feet in length. The mouth must be considered part of it, as it is in the mouth that digestion actually begins ; all starchy foods depending upon the action of the saliva for genuine digestion, saliva having some strange power by which starch is converted into sugar. Swallowed whole, or placed directly in the stomach, such food passes through the body unchanged. Each division of the alimentary canal has its own distinct digestive juice, and I give them in the order in which they occur.
First, The saliva; secreted from the glands of the mouth : — alkaline, glairy, adhesive.
Second, The gastric juice ; secreted in the inner or third lining of the stomach, — an acid, and powerful enough to dissolve all the fiber and albumen of flesh food.
Third, The pancreatic juice ; secreted by the pancreas, which you know in animals as sweetbreads. This juice has a peculiar influence upon fats, which remain unchanged by saliva and gastric juice ; and not until dissolved by pancreatic juice, and made into what chemists call an emulsion, can they be absorbed into the system.
Fourth, The bile ; which no physiologist as yet thoroughly understands. We know its action, but hardly why it acts. It is a necessity, however ; for if by disease the supply be cut off, an animal emaciates and soon dies.
Fifth, The intestinal juice ; which has some properties like saliva, and is the last product of the digestive forces.
A meal, then, in its passage downward is first diluted and increased in bulk by a watery fluid which prepares all
the starchy portion for absorption. Then comes a still more profuse fluid, dissolving all the meaty part. Then the fat is attended to by the stream of pancreatic juice, and at the same time the bile pours upon it, doing its own work in its own mysterious way ; and last of all, lest any process should have been imperfect, the long canal sends out a juice having some of the properties of all. Thus each day's requirements call for
PINTS.
Of saliva .Sf
gastric juice 12
bile 3|
pancreatic juice li
intestinal juice ^
Do not fancy this is all wasted or lost. Very far from it : for the whole process seems to be a second circulation, as it were ; and, while the blood is moving in its wonderful passage through veins and arteries, another circulation as wonderful, an endless current going its unceasing round so long as life lasts, is also taking place. But without food the first would become impossible ; and the quality of food, and its proper digestion, mean good or bad blood as the case may be. We must follow our mouthful of food, and see how this action takes place.
When the different juices have all done their work, the chyme i which is food as it passes from the stomach into the duodenum or passage to the lower stomach or bowels, becomes a milk}^ substance called chyle, which moves slowly, pushed by numberless muscles along the bowel, which squeeze much of it into little glands at the back of the bowels. These are called the mesenteric glands ; and,