THE COMPOSITION OF THE HUMAN BODY
“The lamp of life” is a very old metaphor for the mysterious principle
vitalizing nerve and muscle; but no comparison could be so apt. The
full-grown adult takes in each day, through lungs and mouth, about eight
and a half pounds of dry food, water, and the air necessary for breathing
purposes. Through the pores of the skin, the lungs, kidneys, and lower
intestines, there is a corresponding waste; and both supply and waste
amount in a year to one and a half tons, or three thousand pounds.
The steadiness and clear shining of the flame of a lamp depend upon
quality, as well as amount of the oil supplied, and, too, the texture of
the wick; and so all human life and work are equally made or marred by the
food which sustains life, as well as the nature of the constitution
receiving that food.
Before the nature and quality of food can be considered, we must know the
constituents of the body to be fed, and something of the process through
which digestion and nutrition are accomplished.
I shall take for granted that you have a fairly plain idea of the stomach
and its dependences. Physiologies can always be had, and for minute
details they must be referred to. Bear in mind one or two main points:
that all food passes from the mouth to the stomach, an irregularly-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 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 3-3/4
gastric juice 12
bile 3-3/4
pancreatic juice 1-1/2
intestinal juice 1/2
——-
21-1/2
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_, which is
food as it passes from the stomach into the duodenum or passage to the
lower stomach or bowels, becomes a milky 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, as each one receives its portion of chyle, a
wonderful thing happens. About half of it is changed into small round
bodies called corpuscles, and they float with the rest of the milky fluid
through delicate pipes which take it to a sort of bag just in front of the
spine. To this bag is fastened another pipe or tube–the thoracic
duct–which follows the line of the spine; and up this tube the small
bodies travel till they come to the neck and a spot where two veins meet.
A door in one opens, and the transformation is complete. The small bodies
are raw food no more, but blood, traveling fast to where it may be
purified, and begin its endless round in the best condition. For, as you
know, venous blood is still impure and dirty blood. Before it can be
really alive it must pass through the veins to the right side of the
heart, flow through into the upper chamber, then through another door or
valve into the lower, where it is pumped out into the lungs. If these
lungs are, as they should be, full of pure air, each corpuscle is so
charged with oxygen, that the last speck of impurity is burned up, and it
goes dancing and bounding on its way. That is what health means: perfect
food made into perfect blood, and giving that sense of strength and
exhilaration that we none of us know half as much about as we should. We
get it sometimes on mountain-tops in clear autumn days when the air is
like wine; but God meant it to be our daily portion, and this very
despised knowledge of cookery is to bring it about. If a lung is
imperfect, supplied only with foul air as among the very poor, or diseased
as in consumption, food does not nourish, and you now know why. We have
found that the purest air and the purest water contain the largest
proportion of oxygen; and it is this that vitalizes both food and, through
food, the blood.
To nourish this body, then, demands many elements; and to study these has
been the joint work of chemists and physiologists, till at last every
constituent of the body is known and classified. Many as these
constituents are, they are all resolved into the simple elements, oxygen,
hydrogen, nitrogen, and carbon, while a little sulphur, a little
phosphorus, lime, chlorine, sodium, &c., are added.
FLESH and BLOOD are composed of water, fat, fibrine, albumen, gelatine,
and the compounds of lime, phosphorus, soda, potash, magnesia, iron, &c.
BONE contains cartilage, gelatine, fat, and the salts of lime, magnesia,
soda, &c., in combination with phosphoric and other acids.
CARTILAGE consists of chondrine, a substance somewhat like gelatine, and
contains also the salts of sulphur, lime, soda, potash, phosphorus,
magnesia, and iron.
BILE is made up of water, fat, resin, sugar, cholesterine, some fatty
acids, and the salts of potash, iron, and soda.
THE BRAIN is made up of water, albumen, fat, phosphoric acid, osmazone,
and salts.
THE LIVER unites water, fat, and albumen, with phosphoric and other acids,
and lime, iron, soda, and potash.
THE LUNGS are formed of two substances: one like gelatine; another of the
nature of caseine and albumen, fibrine, cholesterine, iron, water, soda,
and various fatty and organic acids.
How these varied elements are held together, even science with all its
deep searchings has never told. No man, by whatsoever combination of
elements, has ever made a living plant, much less a living animal. No
better comparison has ever been given than that of Youmans, who makes a
table of the analogies between the human body and the steam-engine, which
I give as it stands.
ANALOGIES OF THE STEAM-ENGINE AND THE LIVING BODY.
_The Steam Engine in Action takes_:
1. Fuel: coal and wood, both combustible.
2. Water for evaporation.
3. Air for combustion.
_And Produces_:
4. A steady boiling heat of 212 deg. by quick combustion.
5. Smoke loaded with carbonic acid and watery vapor.
6. Incombustible ashes.
7. Motive force of simple alternate push and pull in the piston, which,
acting through wheels, bands, and levers, does work of endless variety.
8. A deficiency of fuel, water, or air, disturbs, then stops the motion.
_The Animal Body in Life takes_:
1. Food: vegetables and flesh, both combustible.
2. Water for circulation.
3. Air for respiration.
_And Produces_:
4. A steady animal heat, by slow combustion, of 98 deg..
5. Expired breath loaded with carbonic acid and watery vapor.
6. Incombustible animal refuse.
7. Motive force of simple alternate contraction and relaxation in the
muscles, which, acting through joints, tendons, and levers, does work of
endless variety.
8. A deficiency of food, drink, or air, first disturbs, then stops the
motion and the life.
Carrying out this analogy, you will at once see why a person working hard
with either body or mind requires more food than the one who does but
little. The food taken into the human body can never be a simple element.
We do not feed on plain, undiluted oxygen or nitrogen; and, while the
composition of the human body includes really sixteen elements in all,
oxygen is the only one used in its natural state. I give first the
elements as they exist in a body weighing about one hundred and fifty-four
pounds, this being the average weight of a full-grown man; and add a
table, compiled from different sources, of the composition of the body as
made up from these elements. Dry as such details may seem, they are the
only key to a full understanding of the body, and the laws of the body, so
far as the food-supply is concerned; though you will quickly find that the
day’s food means the day’s thought and work, well or ill, and that in your
hands is put a power mightier than you know,–the power to build up body,
and through body the soul, into a strong and beautiful manhood and
womanhood.
ELEMENTS OF THE HUMAN BODY.
———————————————————|——|—–|—–
| Lbs. | Oz. | Grs.
———————————————————|——|—–|—–
1. Oxygen, a gas, and supporter of combustion, | | |
weighs | 103 | 2 | 335
| | |
2. Carbon, a solid; found most nearly pure in charcoal. | | |
Carbon in the body combines with other | | |
elements to produce carbonic-acid gas, and by | | |
its burning sets heat free. Its weight is | 18 | 11 | 150
| | |
3. Hydrogen, a gas, is a part of all bone, blood, and | | |
muscle, and weighs | 4 | 14 | 0
| | |
4. Nitrogen, a gas, is also part of all muscle, blood, | | |
and bone; weighing | 4 | 14 | 0
| | |
5. Phosphorus, a solid, found in brain and bones, | | |
weighs | 1 | 12 | 25
| | |
6. Sulphur, a solid, found in all parts of the body, | | |
weighs | 0 | 8 | 0
| | |
7. Chlorine, a gas, found in all parts of the body, | | |
weighs | 0 | 4 | 150
| | |
8. Fluorine, supposed to be a gas, is found with calcium | | |
in teeth and bones, and weighs | 0 | 3 | 300
| | |
9. Silicon, a solid, found united with oxygen in the | | |
hair, skin, bile, bones, blood, and saliva, weighs | 0 | 0 | 14
| | |
10. Magnesium, a metal found in union with phosphoric | | |
acid in the bones | 0 | 2 | 250
| | |
11. Potassium, a metal, the basis of potash, is found | | |
as phosphate and chloride; weighs | 0 | 3 | 340
| | |
12. Sodium, a metal, basis of soda; weighs | 0 | 3 | 217
| | |
13. Calcium, a metal, basis of lime, found chiefly in | | |
bones and teeth; weighs | 3 | 13 | 190
| | |
14. Iron, a metal essential in the coloring of the | | |
blood, and found everywhere in the body; | | |
weighs | 0 | 0 | 65
| | |
15. Manganese. } Faint traces of both these metals | | |
} | | |
16. Copper metals.} are found in brain and blood, | | |
but in too minute portions to be given by | | |
weight. | | |
|——|—–|—–
Total | 154 | 0 | 0
The second table gives the combinations of these elements; and, though a
knowledge of such combinations is not as absolutely essential as the
first, we still can not well dispense with it. The same weight–one
hundred and fifty-four pounds–is taken as the standard.
COMPOSITION OF THE BODY.
———————————————————|——|—–|—–
| Lbs. | Oz. | Grs.
———————————————————|——|—–|—–
1. Water, which is found in every part of the body, | | |
and amounts to | 109 | 0 | 0
| | |
2. Fibrine, and like substances, found in the blood, | | |
and forming the chief solid materials of the | | |
flesh | 15 | 10 | 0
| | |
3. Phosphate of lime, chiefly in bones and teeth, but | | |
in all liquids and tissues | 8 | 12 | 0
4. Fat, a mixture of three chemical compounds, | | |
and distributed all through the body | 4 | 8 | 0
| | |
5. Osseine, the organic framework of bones; boiled, | | |
gives gelatine. Weight | 4 | 7 | 350
| | |
6. Keratine, a nitrogenous substance, forming the | | |
greater part of hair, nails, and skin. Weighs | 4 | 2 | 0
| | |
7. Cartilagine resembles the osseine of bone, and is a | | |
nitrogenous substance, the chief constituent of | | |
cartilage, weighing | 1 | 8 | 0
| | |
8. Haemoglobine gives the red color to blood, and is | | |
a nitrogenous substance containing iron, and | | |
weighing | 1 | 8 | 0
| | |
9. Albumen is a soluble nitrogenous substance, | | |
found in the blood, chyle, lymph, and muscle, | | |
and weighs | 1 | 1 | 0
| | |
10. Carbonate of lime is found in the bones chiefly, | | |
and weighs | 1 | 1 | 0
| | |
11. Hephalin is found in nerves and brain, with | | |
cerebrine and other compounds | 0 | 13 | 0
| | |
12. Fluoride of calcium is found in teeth and bones, | | |
and weighs | 0 | 7 | 175
| | |
13. Phosphate of magnesia is also in teeth and bones, | | |
and weighs | 0 | 7 | 0
| | |
14. Chloride of sodium, or common salt, is found in | | |
all parts of the body, and weighs | 0 | 7 | 0
| | |
15. Cholesterine, glycogen, and inosite are compounds | | |
containing hydrogen, oxygen, and carbon, | | |
found in muscle, liver, and brain, and | | |
weighing | 0 | 3 | 0
| | |
16. Sulphate phosphate, and salts of sodium, found | | |
in all tissues and liquids | 0 | 2 | 107
| | |
17. Sulphate, phosphate, and chloride of potassium, | | |
are also in all tissues and liquids | 0 | 1 | 300
| | |
18. Silica, found in hair, skin, and bone | 0 | 0 | 30
| | |
| — | — | —
| 154 | 0 | 0
With this basis, to give us some understanding of the complicated and
delicate machinery with which we must work, the question arises, what food
contains all these constituents, and what its amount and character must
be. The answer to this question will help us to form an intelligent plan
for providing a family with the right nutrition.
