ON THE CARE OF HEALTH.
There is no point, where a woman is more liable to suffer from a want of
knowledge and experience, than in reference to the health of a family
committed to her care. Many a young lady, who never had any charge of
the sick; who never took any care of an infant; who never obtained
information on these subjects from books, or from the experience of
others; in short, with little or no preparation; has found herself the
principal attendant in dangerous sickness, the chief nurse of a feeble
infant, and the responsible guardian of the health of a whole family.
The care, the fear, the perplexity, of a woman, suddenly called to
these unwonted duties, none can realize, till they themselves feel it,
or till they see some young and anxious novice first attempting to meet
such responsibilities. To a woman of age and experience, these duties
often involve a measure of trial and difficulty, at times deemed almost
insupportable; how hard, then, must they press on the heart of the young
and inexperienced!
There is no really efficacious mode of preparing a woman to take a
_rational_ care of the health of a family, except by communicating that
knowledge, in regard to the construction of the body, and the laws of
health, which is the basis of the medical profession. Not that a woman
should undertake the minute and extensive investigation requisite for a
physician; but she should gain a general knowledge of first principles,
as a guide to her judgement in emergencies when she can rely on no other
aid. Therefore, before attempting to give any specific directions on the
subject of this chapter, a short sketch of the construction of the human
frame will be given, with a notice of some of the general principles, on
which specific rules in regard to health are based. This description
will be arranged under the general heads of BONES, MUSCLES, NERVES,
BLOOD-VESSELS, ORGANS OF DIGESTION AND RESPIRATION, and THE SKIN.
BONES.
The bones are the most solid parts of the body. They are designed to
protect and sustain it, and also to secure voluntary motion. They are
about two hundred and fifty in number, (there being sometimes a few more
or less,) and are fastened together by cartilage, or gristle, a
substance like the bones, but softer, and more elastic.
In order to convey a more clear and correct idea of the form, relative
position, and connection, of the bones constituting the human framework,
the engraving on page 70, (Fig. 1,) is given.
[Illustration: Fig. 1.]
By the preceding engraving, it will be seen, that the _cranium_, or
_skull_, consists of several distinct pieces, which are united by
sutures, (or seams,) as represented by the zigzag lines; _a_, being the
_frontal bone_; _b_, the _parietal bone_; _c_, the _temporal bone_; and
_d_, the place of the _occipital bone_, which forms the back part of the
head, and therefore is not seen in the engraving. The _nasal bones_, or
bones of the nose, are shown at _e_; _f_, is the _cheek bone_; _g_, the
_upper_, and _h_, the _lower, jaw bones_; _i_, _i_, the _spinal column_,
or back bone, consisting of numerous small bones, called _vertebræ_;
_j_, _j_, the seven _true ribs_, which are fastened to the spine,
behind, and by the _cartilages_, _k_, _k_, to the _sternum_, or _breast
bone_, _l_, in front; _m_, _m_, are the first three _false ribs_, which
are so called, because they are not united directly to the breast bone,
but by cartilages to the seventh true rib; _n_, _n_, are the lower two
_false_, which are also called _floating, ribs_, because they are not
connected with the breast bone, nor the other ribs, in front; _o_, _o_,
_p_, _q_, are the bones of the _pelvis_, which is the foundation on
which the spine rests; _r_, _r_, are the _collar bones_; _s_, _s_, the
_shoulder blades_; _t_, _t_, the bones of the _upper arm_; _u_, _u_, the
_elbow joints_, where the bones of the upper arm and fore arm are united
in such a way that they can move like a hinge; _v_ _w_, _v_ _w_, are the
bones of the _fore arm_; _x_, _x_, those of the _wrists_; _y_, _y_,
those of the _fingers_; _z_, _z_, are the round heads of the thigh
bones, where they are inserted into the sockets of the bones of the
pelvis, giving motion in every direction, and forming the _hip joint_; a
b, a b, are the _thigh bones_; c, c, the _knee joints_; d e, d e, the
_leg bones_; f, f, the _ankle joints_; g, g, the _bones of the foot_.
The bones are composed of two substances,--one animal, and the other
mineral. The animal part is a very fine network, called the _cellular
membrane_. In this, are deposited the harder mineral substances, which
are composed principally of carbonate and phosphate of lime. In very
early life, the bones consist chiefly of the animal part, and are then
soft and pliant. As the child advances in age, the bones grow harder, by
the gradual deposition of the phosphate of lime, which is supplied by
the food, and carried to the bones by the blood. In old age, the hardest
material preponderates; making the bones more brittle than in earlier
life.
As we shall soon have occasion to refer, particularly, to the spinal, or
vertebral column, and the derangement to which it is liable, we give, on
page 72, representations of the different classes of vertebræ; viz. the
_cervical_, (from the Latin, _cervix_, the neck,) the _dorsal_, (from
_dorsum_, the back,) and _lumbar_, (from _lumbus_, the loins.)
[Illustration: Fig. 2.]
Fig. 2, represents one of the _cervical vertebræ_. Seven of these,
placed one above another, constitute that part of the spine which is in
the neck.
[Illustration: Fig. 3.]
Fig. 3, is one of the _dorsal vertebræ_, twelve of which, form the
central part of the spine.
[Illustration: Fig. 4.]
Fig. 4, represents one of the _lumbar vertebræ_, (five in number,)
which are immediately above the sacrum. These vertebræ are so fastened,
that the spine can bend, in any direction; and the muscles of the trunk
are used in holding it erect, or in varying its movements.
By the drawings here presented, it will be seen, that the vertebræ of
the neck, back, and loins, differ somewhat in size and shape, although
they all possess the same constituent parts; thus, A, in each,
represents the body of the vertebræ; B, the articulating processes, by
which each is joined to its fellow, above and below it; C, the spinous
process, or that part of the vertebræ, which forms the ridge to be felt,
on pressure, the whole length of the centre of the back. The back bone
receives its name, _spine_, or _spinal column_, from these spinous
processes.
It is the universal law of the human frame, that _exercise_ is
indispensable to the health of the several parts. Thus, if a
blood-vessel be tied up, so as not to be used, it shrinks, and becomes a
useless string; if a muscle be condemned to inaction, it shrinks in
size, and diminishes in power; and thus it is also with the bones.
Inactivity produces softness, debility, and unfitness for the functions
they are designed to perform. This is one of the causes of the curvature
of the spine, that common and pernicious defect in the females of
America. From inactivity, the bones of the spine become soft and
yielding; and then, if the person is often placed, for a length of time,
in positions that throw the weight of the body unequally on certain
portions of the spine, they yield to this frequent compression, and a
distortion ensues. The positions taken by young persons, when learning
to write or draw, or to play on the guitar, harp, or piano, and the
position of the body when sleeping on one side, on high pillows, all
tend to produce this effect, by throwing the weight of the body
unequally, and for a length of time, on particular parts of the spine.
[Illustration: Fig. 5.]
MUSCLES.
The muscles are the chief organs of motion, and consist of collections
of fine fibres or strings, united in casings of membrane or thin skin.
They possess an elastic power, like India rubber, which enables them to
extend and contract. The red meat in animals consists of muscles. Every
muscle has connected with it nerves, veins, and arteries; and those
designed to move the bones, are fastened to them by tendons at their
extremities. The muscles are laid over each other, and are separated by
means of membranes and layers of fat, which enable them to move easily,
without interfering with each other.
The figure on page 74, represents the muscles of the arm, as they appear
when the skin and fat are removed. The muscles _a_ and _b_ are attached,
at their upper ends, to the bone of the arm, and by their lower ends to
the upper part of the fore arm, near the elbow joint. When the fibres of
these muscles contract, the middle part of them grows larger, and the
arm is bent at the elbow. The muscle _c_, is, in like manner, fastened,
by its upper end, to the shoulder blade and the upper part of the arm,
and by its lower end to one of the bones of the fore arm, near the
elbow. When the arm is bent, and we wish to straighten it, it is done by
contracting this muscle. The muscles _d_, _d_, are fastened at one end
near the elbow joint, and at the other near the ends of the fingers; and
on the back of the hand are reduced in size, appearing like strong
cords. These cords are called _tendons_. They are employed in
straightening the fingers, when the hand is shut. These tendons are
confined by the ligament or band, _e_, which binds them down, around the
wrist, and thus enables them to act more efficiently, and secures beauty
of form to the limb. The muscles at _f_, are those which enable us to
turn the hand and arm outward. Every different motion of the arm has one
muscle to produce it, and another to restore the limb to its natural
position. Those muscles which bend the body are called _flexors_; those
which straighten it, _extensors_. When the arm is thrown up, one set of
muscles is used; to pull it down, another set: when it is thrown
forward, a still different set is used; when it is thrown back,
another, different from the former; when the arm turns in its socket,
still another set is used; and thus every different motion of the body
is made by a different set of muscles. All these muscles are compactly
and skilfully arranged, so as to work with perfect ease. Among them, run
the arteries, veins, and nerves, which supply each muscle with blood and
nervous power, as will be hereafter described. The size and strength of
the muscles depend greatly on their frequent exercise. If left inactive,
they grow thin and weak, instead of giving the plumpness to the figure,
designed by Nature. The delicate and feeble appearance of many American
women, is chiefly owing to the little use they make of their muscles.
Many a pale, puny, shad-shaped girl, would have become a plump, rosy,
well-formed person, if half the exercise, afforded to her brothers in
the open air, had been secured to her, during childhood and youth.
NERVES.
The nerves are the organs of sensation. They enable us to see, hear,
feel, taste, and smell; and also combine with the bones and muscles in
producing motion.
The first engraving, on p. 77, (Fig. 6,) is a vertical section of the
skull, and of the spinal column, or back bone, which supports the head,
and through which runs the spinal cord, whence most of the nerves
originate. It is a side view, and represents the head and spine, as they
would appear, if they were cut through the middle, from front to back.
Fig. 7, exhibits them as they would appear, if viewed from _behind_. In
Fig. 6, _a_, represents the _cerebrum_, or great brain; _b_, the
_cerebellum_, or little brain, which is situated directly under the
great brain, at the back and lower part of the head; _c_, _d_, _e_, is
the spinal marrow, which is connected with the brain at _c_, and runs
through the whole length of the spinal column. This column consists, as
has already been stated, of a large number of small bones, _f_, _f_,
called _vertebræ_, laid one above another, and fastened together by
_cartilage_, or _gristle_, _g_, between them.
[Illustration: Fig. 6.]
[Illustration: Fig. 7.]
Between each two vertebræ, or spinal bones, there issues from the
spine, on each side, a pair of nerves. The lower broad part of the
spine, (see _p_, Fig. 1, p. 70, and Fig. 7, p. 77,) is called the
_sacrum_; in this, are eight holes, through which the lower pairs of
nerves pass off.
The nerves of the head and lungs run directly from the brain; those of
all other parts of the body proceed from the spine, passing out in the
manner already mentioned.
The nerves which thus proceed from the spine, branch out, like the limbs
and twigs of a tree, till they extend over the whole body; and, so
minutely are they divided and arranged, that a point, destitute of a
nerve, cannot be found on the skin.
Some idea of the ramifications of the nerves, may be obtained by
reference to the following engraving, (Fig. 8.) In this, A, A,
represents the _cerebrum_, or great brain; B, B, the _cerebellum_, or
little brain; (see also _a_, _b_, in Fig. 6;) C, C, represents the union
of the fibres of the cerebrum; D, D, the union of the two sides of the
cerebellum; E, E, E, the spinal marrow, which passes through the centre
of the spine, (as seen at _c_, _d_, _e_, in Fig. 6;) 1, 2, 3, 4, 5, 6,
branches of the nerves going to different parts of the body. As the
nerves are the organs of sensation, all _pain_ is an affection of some
portion of the nerves. The health of the nerves depends very greatly on
the exercise of the muscles, with which they are so intimately
connected. This shows the reason why the _headache_, _tic douloureux_,
diseases of the _spine_, and other nervous affections, are so common
among American women. Their inactive habits, engender a debility of the
nervous system, and these diseases follow, as the consequence.
[Illustration: Fig. 8.]
It can be seen, by a reference to the side view, represented on page
77, (Fig. 6,) that the spine is naturally curved back and forward.
When, from want of exercise, its bones are softened, and the muscles
weakened, the spine acquires an improper curve, and the person becomes
what is called _crooked_, having the neck projected forward, and, in
some cases, having the back convex, where it should be concave. Probably
one half of the American women have the head thus projecting forward,
instead of carrying it in the natural, erect position, which is both
graceful and dignified.
The curvature of the spine, spoken of in this work as so common, and as
the cause of so many diseases among American women, is what is
denominated the _lateral curvature_, and is much more dangerous than the
other distortion. The indications of this evil, are, the projection of
one shoulder blade more than the other, and, in bad cases, one shoulder
being higher, and the hip on the opposite side more projecting, than the
other. In this case, the spine, when viewed from behind, instead of
running in a straight line, (as in Fig. 7 and 9,) is curved somewhat, as
may be seen in Figures 10 and 11.
This effect is occasioned by the softness of the bones, induced by want
of exercise, together with tight dressing, which tends to weaken the
muscles that are thus thrown out of use. Improper and long continued
positions in drawing, writing, and sleeping, which throw the weight of
the body on one part of the spine, induce the same evil. This distortion
is usually accompanied with some consequent disease of the nervous
system, or some disarrangement of the internal organs.
By comparing Figures 9 and 11, the difference between a natural and
distorted spine will be readily perceived. In Fig. 10, the curved line
shows the course of the spine, occasioned by distortion; the
perpendicular line, in this and Fig. 11, indicates the true direction of
the spine; the horizontal lines show that one shoulder and hip are
forced from their proper level.
[Illustration: Fig. 9.]
[Illustration: Fig. 10.]
[Illustration: Fig. 11.]
BLOOD-VESSELS.
The blood is the fluid into which our food is changed, and which is
employed to minister nourishment to the whole body. For this purpose, it
is carried to every part of the body, by the arteries; and, after it has
given out its nourishment, returns to the heart, through the veins.
The subjoined engraving, (Fig. 12,) which presents a rude outline of the
vascular system, will more clearly illustrate this operation, as we
shall presently show.
[Illustration: Fig. 12.]
Before entering the heart, the blood receives a fresh supply of
nourishment, by a duct which leads from the stomach. The arteries have
their origin from the heart, in a great trunk, called the _aorta_, which
is the parent of all the arteries, as the spinal marrow is the parent of
the nerves which it sends out. When the arteries have branched out into
myriads of minute vessels, the blood which is in them passes into as
minute veins; and these run into each other, like the rills and branches
of a river, until they are all united in two great veins, which run into
the heart. One of these large receivers, called the _vena cava
superior_, or _upper vena cava_, brings back the blood from the arms and
head, the other, the _vena cava inferior_, or _lower vena cava_, brings
back the blood from the body and lower limbs.
In the preceding figure, H, is the heart, which is divided into four
compartments; two, called _auricles_, used for receiving the blood, and
two, called _ventricles_, used for sending out the blood. A, is the
_aorta_, or great artery, which sends its branches to every part of the
body. In the upper part, at _a_, _a_, _a_, are the main branches of the
_aorta_, which go to the head and arms. Below, at _a_, _a_, are the
branches which go to the lower limbs. The branches which set off at X,
X, are those by which the intestines are supplied by vessels from the
_aorta_. Every muscle in the whole body, all the organs of the body, and
the skin, are supplied by branches sent off from this great _artery_.
When the blood is thus dispersed through any organ, in minute vessels,
it is received, at their terminations, by numerous minute veins, which
gradually unite, forming larger branches, till they all meet in either
the upper or lower _vena cava_, which returns the blood to the heart. V
I, is the _vena cava inferior_, which receives the blood from the veins
of the lower parts of the body, as seen at v, v. The blood, sent into
the lower limbs from the _aorta_, is received by minute veins, which
finally unite at v, v, and thus it is emptied through the lower _vena
cava_ into the heart: _o_, _o_, represent the points of entrance of
those tributaries of the _vena cava_, which receive that blood from the
intestines, which is sent out by the _aorta_ at X, X. In the upper part,
V S, is the _vena cava superior_, which receives the blood from the head
and arms; v, v, v, are the tributaries of the upper _vena cava_, which
bring the blood back from the head and arms; _d_, _d_, represents the
course of the _thoracic duct_, a delicate tube by which the chyle is
carried into the blood, as mentioned on page 89; _t_, shows the place
where this duct empties into a branch of the _vena cava_.
It thus appears, that wherever a branch of the _aorta_ goes to carry
blood, there will be found a tributary of the upper or lower _vena
cava_, to bring it back.
The succeeding engravings, will enable the reader to form a more
definite idea of this important function of the system,--the circulation
of the blood. The heart, in man, and in all warm-blooded animals, is
double, having two auricles and two ventricles. In animals with cold
blood, (as fishes,) the heart is single, having but one auricle and one
ventricle. Fig. 13, represents the double heart as it appears when the
two sides are separated, and also the great blood-vessels; those on the
left of the figure being on the right side of the body, and _vice
versa_. The direction of the blood is represented by the arrows. A,
represents the _lower vena cava_, returning the blood from the lower
parts of the body, and L, the _upper vena cava_, returning the blood
from the head and arms. B, is the _right sinus_, or _auricle_, into
which the returned blood is poured. From this cavity of the heart, the
blood is carried into the _right ventricle_, C; and from this ventricle,
the _pulmonary arteries_, D, convey into the lungs the blood which is
returned from the body. These five vessels, A, B, C, D, and L, belong to
the right side of the heart, and contain the venous or dark-colored
blood, which has been through the circulation, and is now unfit for the
uses of the system, till it has passed through the lungs.
[Illustration: Fig. 13.]
When the blood reaches the lungs, and is exposed to the action of the
air which we breathe, it throws off its impurities, becomes bright in
color, and is then called arterial blood. It then returns to the left
side of the heart, (on the right of the engraving,) by the pulmonary
veins E, E, (also seen at _m_, _m_, Fig. 15,) into the left auricle F,
whence it is forced into the ventricle, G. From the left ventricle,
proceeds the _aorta_, H, H, which is the great artery of the body, and
conveys the blood to every part of the system. I, J, K, are branches of
the aorta, going to the head and arms.
[Illustration: Fig. 14.]
Fig. 14, represents the heart, with its two sides united as in nature;
and will be understood from the description of Fig. 13.
On the opposite page, Fig. 15, represents the heart, with the great
blood-vessels, on a still larger scale; _a_, being the _left ventricle_;
_b_, the _right ventricle_; _c_, _e_, _f_, the _aorta_, or great artery,
rising out of the left ventricle; _g_, _h_, _i_, the branches of the
aorta, going to the head and arms; _k_, _l_, _l_, the _pulmonary
artery_, and its branches; _m_, _m_, _veins of the lungs_, which bring
the blood back from the lungs to the heart; _n_, _right auricle_; _o_,
_vena cava inferior_; _p_, veins returning blood from the liver and
bowels; _q_, the _vena cava superior_; _r_, the _left auricle_; _s_, the
left _coronary artery_, which distributes the blood exclusively to the
substance of the heart.
[Illustration: Fig. 15.]
ORGANS OF DIGESTION AND RESPIRATION.
Digestion and respiration are the processes, by which the food is
converted into blood for the nourishment of the body. The engraving on
the next page (Fig. 16) shows the organs by which these operations are
performed.
In the lower part of the engraving, is the stomach, marked S, which
receives the food through the _gullet_, marked G. The latter, though in
the engraving it is cut off at G, in reality continues upwards to the
throat. The stomach is a bag composed of muscles, nerves, and
blood-vessels, united by a material similar to that which forms the
skin. As soon as food enters the stomach, its nerves are excited to
perform their proper function of stimulating the muscles. A muscular
(called the _peristaltic_) motion immediately commences, by which the
stomach propels its contents around the whole of its circumference, once
in every three minutes.
[Illustration: Fig. 16.]
This movement of the muscles attracts the blood from other parts of the
system; for the blood always hastens to administer its supplies to any
organ which is called to work. The blood-vessels of the stomach are soon
distended with blood, from which the _gastric juice_ is secreted by
minute vessels in the coat of the stomach. This mixes with the food,
and reduces it to a soft pulpy mass, called chyme. It then passes
through the lower end of the stomach, into the intestines, which are
folded up in the abdomen, and the upper portion, only, of which, is
shown in the engraving, at A, A. The organ marked L, L, is the liver,
which, as the blood passes through its many vessels, secretes a
substance called _bile_, which accumulates in the gall-bladder, marked
B. After the food passes out of the stomach, it receives from the liver
a portion of bile, and from the _pancreas_ the _pancreatic juice_. The
pancreas does not appear in this drawing, being concealed behind the
stomach. These two liquids separate the substance which has passed from
the stomach, into two different portions. One is a light liquid, very
much like cream in appearance, and called _chyle_, of which the blood is
formed; the other is a more solid substance, which contains the refuse
and useless matter, with a smaller portion of nourishment; and this,
after being further separated from the nourishing matter which it
contains, is thrown out of the body. There are multitudes of small
vessels, called _lacteals_, which, as these two mixed substances pass
through the long and winding folds of the intestines in the abdomen,
absorb the chyle, and convey it to the _thoracic duct_, which runs up
close by the spine, and carries the chyle, thus received, into a branch
of the _vena cava superior_, at _t_, whence it is mingled with the blood
going into the heart. In this engraving, the _lacteals_ and _thoracic
duct_ are not shown; but their position is indicated by the dotted
lines, marked X, Y; X, being the lacteals, and Y, the thoracic duct.
In the upper half of the engraving, H represents the heart; _a_, the
commencement of the _aorta_; _v c s_, the termination of the _vena cava
superior_. On each side of the heart, are the lungs; _l l_, being the
left lobe, and _r l_, the right lobe. They are composed of a network of
air-vessels, blood-vessels, and nerves. W, represents the _trachea_, or
_windpipe_, through which, the air we breathe is conducted to the lungs.
It branches out into myriads of minute vessels, which are thus filled
with air every time we breathe. From the heart, run the _pulmonary
arteries_, marked _p a_. These enter the lungs and spread out along-side
of the branches of the air-vessels, so that every air-vessel has a small
artery running side by side with it. When the two _vena cavas_ empty the
blood into the heart, the latter contracts, and sends this blood,
through these pulmonary arteries, into the lungs.
As the air and blood meander, side by side, through the lungs, the
superabundant carbon and hydrogen of the blood combine with the oxygen
of the air, forming carbonic acid gas, and water, which are thrown out
of the lungs at every expiration. This is the process by which the chyle
is converted into arterial blood, and the venous blood purified of its
excess of carbon and hydrogen. When the blood is thus prepared, in the
lungs, for its duties, it is received by the small _pulmonary veins_,
which gradually unite, and bring the blood back to the heart, through
the large _pulmonary veins_, marked _p v_, _p v_.
On receiving this purified blood from the lungs, the heart contracts,
and sends it out again, through the _aorta_, to all parts of the body.
It then makes another circuit through every part, ministering to the
wants of all, and is afterwards again brought back by the veins to
receive the fresh chyle from the stomach, and to be purified by the
lungs.
The throbbing of the heart is caused by its alternate expansion and
contraction, as it receives and expels the blood. With one throb, the
blood is sent from the right ventricle into the lungs, and from the left
ventricle into the aorta.
Every time we inspire air, the process of purifying the blood is going
on; and every time we expire the air, we throw out the redundant carbon
and hydrogen, taken from a portion of the blood. If the waist is
compressed by tight clothing, a portion of the lungs be compressed, so
that the air-vessels cannot be filled. This prevents the perfect
purification and preparation of the blood, so that a part returns back
to the heart unfitted for its duties. This is a slow, but sure, method,
by which the constitution of many a young lady is so undermined that she
becomes an early victim to disease and to the decay of beauty and
strength. The want of _pure air_ is another cause, of the debility of
the female constitution. When air has been rendered impure, by the
breath of several persons, or by close confinement, it does not purify
the blood properly. Sleeping in close chambers, and sitting in crowded
and unventilated schoolrooms, are frequent causes of debility in the
constitution of young persons.
OF THE SKIN.
The skin is the covering of the body, and has very important functions
to perform. It is more abundantly supplied with nerves and blood-vessels
than any other part; and there is no spot of the skin where the point of
the finest needle would not pierce a nerve and blood-vessel. Indeed, it
may be considered as composed chiefly of an interlacing of minute nerves
and blood-vessels, so that it is supposed there is more nervous matter
in the skin, than in all the rest of the body united, and that the
greater portion of the blood flows through the skin.
The whole animal system is in a state of continual change and
renovation. Food is constantly taken into the stomach, only a portion of
which is fitted for the supply of the blood. All the rest has to be
thrown out of the system, by various organs designed for this purpose.
These organs are,--the lungs, which throw off a portion of useless
matter when the blood is purified; the kidneys, which secrete liquids
that pass into the bladder, and are thrown out from the body by that
organ; and the intestines, which carry off the useless and more solid
parts of the food, after the lacteals have drawn off the chyle. In
addition to these organs, the skin has a similar duty to perform; and as
it has so much larger a supply of blood, it is the chief organ in
relieving the body of the useless and noxious parts of the materials
which are taken for food.
Various experiments show, that not less than a pound and four ounces of
waste matter is thrown off by the skin every twenty-four hours. This is
according to the lowest calculation. Most of those, who have made
experiments to ascertain the quantity, represent it as much greater; and
all agree, that the skin throws off more redundant matter from the body,
than the whole of the other organs together. In the ordinary state of
the skin, even when there is no apparent perspiration, it is constantly
exhaling waste matter, in a form which is called _insensible
perspiration_, because it cannot be perceived by the senses. A very cool
mirror, brought suddenly near to the skin, will be covered, in that
part, with a moisture, which is this effluvium thus made visible. When
heat or exercise excites the skin, this perspiration is increased, so as
to be apparent to the senses. This shows the reason why it is so
important frequently to wash the entire surface of the body. If this be
neglected, the pores of the skin are closed by the waste matter thrown
from the body, and by small particles of the thin scarfskin, so that it
cannot properly perform its duties. In this way, the other organs are
made to work harder, in order to perform the labor the skin would
otherwise accomplish, and thus the lungs and bowels are often
essentially weakened.
Another office of the skin, is, to regulate the heat of the body. The
action of the internal organs is constantly generating heat; and the
faster the blood circulates, the greater is the heat evolved. The
perspiration of the skin serves to reduce and regulate this heat. For,
whenever any liquid changes to a vapor, it absorbs heat from whatever is
nearest to it. The faster the blood flows, the more perspiration is
evolved. This bedews the skin with a liquid, which the heat of the body
turns to a vapor; and in this change, that heat is absorbed. When a
fever takes place, this perspiration ceases, and the body is afflicted
with heat. Insensible perspiration is most abundant during sleep, after
eating, and when friction is applied to the skin. Perspiration is
performed by the terminations of minute arteries in every part of the
skin, which exude the perspiration from the blood.
The skin also performs another function. It is provided with a set of
small vessels, called _absorbents_, which are exceedingly abundant and
minute. When particular substances are brought in contact with the skin,
these absorbents take up some portions and carry them into the blood. It
is owing to this, that opium, applied on the skin, acts in a manner
similar to its operation when taken into the stomach. The power of
absorption is increased by friction; and this is the reason that
liniments are employed, with much rubbing, to bruises and sprains. The
substance applied is thus introduced into the injured part, through the
absorbents. This shows another reason for frequent washing of the skin,
and for the frequent changes of the garment next the skin. Otherwise
portions of the noxious matter, thrown out by the skin, are reabsorbed
into the blood, and are slow but sure causes of a decay of the strength
of the system.
The skin is also provided with small follicles, or bags, which are
filled with an oily substance. This, by gradually exuding over the skin,
prevents water from penetrating and injuring its texture.
The skin is also the organ of touch. This office is performed through
the instrumentality of the nerves of feeling, which are spread over all
parts of the skin.
This general outline of the construction of the human frame is given,
with reference to the practical application of this knowledge in the
various cases where a woman will be called upon to exercise her own
unaided judgement. The application will be further pointed out, in the
chapters on Food, Dress, Cleanliness, Care of the Sick, and Care of
Infants.