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Hygienic Physiology

J >> Joel Dorman Steele >> Hygienic Physiology




"...'She is conscious now,' I heard one of the doctors say, and he gently
lifted the lids of my eyes and looked into them. I tried my best to throw
all the intelligence I could into them, and returned his look with one of
recognition. But, even with my eyes fixed on his, I felt myself going
again in spite of my craving to stay. I longed to implore the doctor to
save me, to keep me from the unutterable anguish of falling into the
vastness and vagueness of that shadowy sea of nothingness again. I clasped
my hands in wild entreaty; I was shaken by horrible convulsions--so, at
least, it seemed to me at the time--but, beyond a slight quivering of the
fingers, no movement was discernible by the others....For five hours I
remained in the same condition--short intervals of half-consciousness and
then long lapses into the agonizing experiences I have described....Coming
out of the last trance, I discovered that the measured rending report like
the discharge of a cannon, which attended my upward way, was the throbbing
of my own heart."]

Concerning all these and other narcotics, it should never be forgotten
that they are true poisons, sold with the mark of skull and crossbones,
useful, like strychnine and henbane, in the hands of a skillful physician,
but fraught with deadly danger when otherwise employed. Their private use
is never safe. The weak and nervous invalid, who can not by hygienic means
build up new strength, need never hope to gain it by surreptitiously
indulging in popular narcotics. Instead, he will soon discover that he has
but added to his list of ills a new and fatal one.--E. B. S.

THE SPECIAL SENSES.

AN EDUCATED SENSE OF TOUCH (p. 230).--Laura Dewey Bridgman, teacher in the
Perkins Institute for the Blind, South Boston, lost her sight, hearing,
and sense of smell, when she was two years of age. At the age of eight
years she was taken to the institution where she yet remains. At this
time, by following her mother around the house she had become familiar
with home appointments, and by feeling her mother's hands and arms had
also learned to sew and knit. When she first became an inmate of the
Perkins Institute, she was bewildered by her strange surroundings, but
after she had become used to place and people, through her one and only
sense, her education was carefully begun. Through indomitable effort on
the part of her preceptor, she was taught to write, read, and spell, by
means of her fingers, and thus to exchange sentiments with her teachers
and with others skilled in the mysterious language of the blind and the
mute. She is now as proficient in the ordinary branches of learning as is
the average person, possessed of all the senses. Her studies include
geography, arithmetic, algebra, geometry, history, and philosophy. She
makes her own clothing, can run a sewing machine, and observes great
neatness in her dress and the arrangements of her room. Her character is
religious, and she has great success as a teacher. Not long since, she
celebrated, on the same day, her fifty-eighth birthday and the fiftieth
anniversary of her entrance to the Perkins Institute. During her earlier
years, it was her practice to keep a journal, and she now has about forty
manuscript books of her own making. She has also written three
autobiographical sketches, several poems, and is an accomplished
correspondent. When Miss Bridgman expresses pleasure, she clasps her hands
and smiles. So keen and refined are her sensibilities, that it is said she
can, in a small way, appreciate the beauty of music by means of the sound
vibrations on the floor.--MRS. GEORGE ARCHIBALD. (Laura D. Bridgman died
in 1889.)

THE NOSE (p. 232).--_The Anatomy of the Nose_.--Probably most of us
look upon the nose as a double hole in the head, by which we get, with
more or less acuteness, a sense of smell, and through which we
occasionally breathe. The intricate mechanism, and the skillful adaptation
of means to end, which, in common with the other organs of special sense,
it exhibits, naturally do not reveal themselves to any but the students of
anatomy and physiology. Its fourteen bones are probably better hidden than
any other fourteen bones of the body, and assist in converting what would
otherwise be a mere channel of communication, into a series of cavities
designed and adapted for particular purposes. The arch of four bones which
forms the bridge of the nose, and which is of such strength as to enable
the gymnast of the circus to perform the feat of supporting with it a man
on a ladder, is pieced on with cartilage to form the nostrils, through
which the nose communicates with the outer air. Similar openings behind
connect it with the upper and posterior parts of the mouth. The space
between these anterior and posterior openings makes a large chamber,
divided by a vertical wall into halves, each of which is still further
separated into three irregular cavities by three bones, called spongy,
from the porosity and delicacy of their texture. The ceiling of these
chambers is formed by a bone of the thinness of paper, upon which lies the
front part of the brain,--a fact the Egyptians made use of in embalming
their corpses, easily crushing this bone, and extracting the brain through
the nostrils. This bone is called cribriform (sieve-like), because it is
perforated by many minute holes, through which, from the olfactory bulbs
(specialized parts of the brain in which is resident the capacity of
smell) that rest on its upper surface, issue the delicate filaments of the
olfactory nerves, to spread themselves over the lining membrane of the two
upper spongy bones. It is in the upper chambers of the nose, therefore,
that the function of smell is performed; the nerves that supply the lower
spongy bone being entirely unconnected with the organs of smell. Over
these latter, however, sweep in and out the currents of air when the act
of respiration is properly carried out, and it is these that are
especially concerned in its abnormal performance. Usually but a very
little of the volume of air that traverses the lower chamber of the nose
has any influence upon its upper regions; and therefore, when our
attention is attracted by an odor, we sniff, in order to bring a larger
quantity of air into contact with the higher parts of the nose, or
olfactory cavities, where odors are perceived.

But the half has not been told of the anatomical and physiological
arrangements of the nose. By minute openings its chambers have
communication with many other parts of the head,--with the hollow that
forms the greater part of the cheek bone; with the eye by a minute spout
that carries off the lachrymal secretion, unless the tears are so abundant
as to roll down the cheeks; with the front of the roof of the mouth; with
the abundant cells of the bone that makes the forehead, and the congestion
of whose lining membrane probably accounts for the severe headache that so
often accompanies and aggravates a "cold in the head." The gateway to the
inner air passages, its abundant surfaces raise the air inspired to the
temperature of the body, supply it with the moisture it lacks, and sift
from it more or less of the mechanical impurities with which the
atmosphere of our houses and shops is laden.--MAURICE D. CLARKE, M.D.,
_Popular Science News, April, 1888_.

_Smell Necessary to Taste_.--What we are in the habit of calling a
"taste," is in most cases a compound of smell, taste, temperature, and
touch--these four sensations ranking in gastronomic importance in the
order in which they are here named....Amusing experiments may be made,
showing that without the sense of smell it is commonly quite impossible to
distinguish between different articles of food and drink. Blindfold a
person and make him clasp his nose tightly, then put successively into his
mouth small pieces of beef, mutton, veal, and pork, and it is safe to
predict that he will not be able to tell one morsel from another. The same
result will be obtained with chicken, turkey, and duck; with pieces of
almond, walnut, and hazel-nut; with slices of apple, peach, and pear; or
with different kinds of cheese, if care be taken that such kinds are
chosen as do not, by their peculiar composition, betray their identity
through the nerves of touch in the mouth. To hold an article of food under
the nose at table would be justly considered a breach of etiquette. But
there is a second way of smelling, of which most people are quite
unconscious, viz., by _exhaling through the nose_ while eating and
drinking....It is well known that only a small portion of the mucous
membrane which lines the nostrils is the seat of the endings of the nerves
of smell. In ordinary expiration, the air does not touch this olfactory
region, but by a special effort it can be turned into that
direction....Instinct teaches most persons while eating to guide the air,
impregnated with the fragrance of the food, to a part of the nostrils
different from that used during ordinary exhalation; but, being
unaccustomed to psychologic analysis of their sensations, they remain
quite unconscious of this proceeding, and are, indeed, in the habit of
confusing their sensations of taste, smell, touch, and temperature in a
most absurd manner....

In trying to ascertain by experiment how far smell, touch, and temperature
enter into this compound sensation, popularly known as "taste," it is best
to make use of the pungent condiments. Mustard and horse-radish, for
example, have little or no taste, but reserve their pungent effect for the
mucous membrane of the nose during expiration. It is an advantage to know
this, for if care is taken to breathe only through the mouth, we need no
longer prepare to shed tears every time we help ourselves to the mustard.
The pungent quality of mustard, the fiery quality of ginger, and the cool
sensation in the mouth after eating peppermint, are due to the nerves of
touch and temperature, which are commonly classed as one sense, though
they are quite as distinct sensations as sight and hearing, or taste and
smell....

There are two ways in which the effort to extract all its fragrance from a
morsel of food confers a benefit.

(1.) It is necessary to keep the morsel in the mouth as long as possible.
Now the habit thus formed of eating very slowly is of the utmost
importance, for if farinaceous articles of food are swallowed before the
saliva has had time to act on them, they are little better than so much
waste material taken into the system; and if meat is not thoroughly
masticated, the stomach is overloaded with work which should have been
done by the teeth; the result, in either case, is dyspepsia. It has been
suggested that Mr. Gladstone owes his remarkable physical vigor to certain
rules for chewing food, which he adopted in 1848, and to which he has
adhered ever since. "He had always," we are told, "paid great attention to
the requirements of Nature, but he then laid down as a rule for his
children that thirty-two bites should be given to each mouthful of meat,
and a somewhat lesser number to bread, fish, etc."

(2.) Besides this indirect advantage resulting from the effort to get at
the fragrant odors of food, there is a still more remarkable direct
advantage. It is one of the most curious psychologic facts that odors
exert a strong influence on our system, either exhilarating or depressing.
While an unpleasant odor may cause a person to faint, the fumes of the
smelling bottle will restore him to consciousness. The magic and value of
gastronomic odors lies in this, that they stimulate the flow of saliva and
other alimentary juices, thus making sure that the food eaten will be
thoroughly utilized in renovating the system.--HENRY T. FINCK, _in "The
Gastronomic Value of Odors_." HYGIENE OF THE EAR (p. 236).--_Never
Box a Child's Ear_.--Children and grown persons alike may be entirely
deafened by falls or heavy blows upon the head. Boxing the ears produces a
similar effect, though more slowly and in less degree, and tends to dull
the sensibility of the nerve, even if it does not hurt the membrane. I
knew a youth who died from a terrible disease of the ear. There had been a
discharge from it since he was a child. Of course his hearing had been
dull; and _his father had often boxed his ear for inattention!_ Most
likely that boxing on the ear, diseased as it was, had much to do with his
death. And this brings me to the second point. Children should never be
blamed for being inattentive, until it has been found out whether they are
not a little deaf. This is easily done by placing them at a few yards'
distance, and trying whether they can understand what is said to them in a
rather low tone of voice. Each ear should be tried, while the other is
stopped by the finger. Three things should be remembered here: 1. That
slight degrees of deafness, often lasting only for a time, are very common
among children, especially during or after colds. 2. That a slight
deafness, which does not prevent a person from hearing when he is
expecting to be spoken to, will make him very dull to what he is not
expecting. 3. That there is a kind of deafness in which a person can hear
pretty well while listening, but is really very hard of hearing when not
listening.

_Avoid Direct Draughts in the Ear_.--There are some exposures
especially to be guarded against. One is sitting or driving with the ear
exposed to a side wind. Deafness has also been known to come from letting
rain or sleet drive into the ear.

_Do not Remove the Earwax_.--It ought to be understood that the
passage of the ear does not require cleaning by us. Nature undertakes that
task, and, in the healthy state, fulfills it perfectly. Her means for
cleansing the ear is _the wax_. Perhaps the reader has never wondered
what becomes of the earwax. I will tell him. It dries up into thin fine
scales, and these peel off, one by one, from the surface of the passage,
and fall out imperceptibly, leaving behind them a perfectly clean, smooth
surface. In health the passage of the ear is never dirty; but, if we
attempt to clean it, we infallibly make it so. Washing the ear out
frequently with soap and water keeps the wax moist when it ought to become
dry and scaly, increases its quantity unduly, and makes it absorb the dust
with which the air always abounds. But the most hurtful thing is
introducing the corner of the towel, screwed up, and twisting it round.
This does more harm to ears than all other mistakes together. It drives
down the wax upon the membrane, much more than it gets it out. But this
plan does much more mischief than merely pressing down the wax. It
irritates the passage, and makes it cast off small flakes of skin, which
dry up, and become extremely hard, and these also are pressed down upon
the membrane. Often it is not only deafness which ensues, but pain and
inflammation, and then matter is formed which the hard mass prevents from
escaping, and the membrane becomes permanently diseased.

_The Eustachian Tube_.--The use of this tube is twofold. First, it
supplies the drum with air, and keeps the membrane exactly balanced, and
free to move, with equal air pressure on each side; and, secondly, it
carries off any fluid which may be in the drum, and prevents it from being
choked by its own moisture. It is not always open, however, but is opened
during the act of swallowing, by a little muscle which is attached to it
just as it reaches the throat. Most persons can distinctly feel that this
is the case, by gently closing the nose and swallowing, when a distinct
sensation is felt in the ears. This sensation is due to a little air being
drawn out of the ears through the open tube during swallowing; and it
lasts for a few minutes, unless the air is again restored by swallowing
with the nose unclosed, which allows for the moment a free communication
between the ear and the throat. We thus see a reason for the tube being
closed. If it were always open, all the sounds produced in the throat
would pass directly into the drum of the ear, and totally confuse us. We
should hear every breath, and live in a constant bewilderment of internal
sounds. At the same time the closure, being but a light contact of the
walls of the tube, easily allows a slight escape of air _from_ the
drum, and thus not only facilitates and regulates the oscillations of the
air before the vibrating membrane, but provides a safety valve, to a
certain extent, against the injurious influence of loud sounds.

The chief use of the Eustachian tube is to allow a free interchange of air
between the ear and the throat, and it is very important that its use in
this respect should be understood. Persons who go down in diving bells
soon begin to feel a great pressure in the ears, and, if the depth is
great, the feeling becomes extremely painful. This arises from the fact
that in the diving bell the pressure of the air is very much increased, in
order to balance the weight of the water above; and thus it presses with
great force upon the membrane of the drum, which, if the Eustachian tube
has been kept closed, has only the ordinary uncompressed air on the inner
side to sustain it. It is therefore forced inward and put upon the
stretch, and might be even broken. Many cases, indeed, have occurred of
injury to the ear, producing permanent deafness, from descents in diving
bells, undertaken by persons ignorant of the way in which the ear is made;
though the simple precaution of frequent swallowing suffices to ward off
all mischief. For, if the Eustachian tube is thus opened, again and again,
as the pressure of the outside air increases, the same compressed air that
exists outside passes also into the inside of the drum, and the membrane
is equally pressed upon from both sides by the air, and so is free from
strain. The same precaution is necessary in ascending lofty mountains.--
DR. JAMES HINTON.

THE COLORED CURTAIN IN THE EYE (p. 238).--This ring-like curtain in the
eye, of gray, green, bluish-green, brown, and other colors, is one among
the very many remarkable contrivances of the organic world. The eye can
not bear the entrance of too much light, and the colored curtain so
regulates its own movements as to serve this requirement. The dark
circular aperture in the center, known as the pupil, is consequently
forever altering in size; on a bright, sunshiny day, out in the open, it
may be only the size of a pin's head, but at night, when there is no light
stronger than starlight, it is even bigger than a pea. The eye curtain is
fixed at its outer edge, leaving the inner edge to contract or expand,
which it does automatically and quite independent of the will, ever
preserving its circular outline. Its movements may be watched in a variety
of ways, some of which we shall describe.

The common way of watching the movements of the iris is to regard it
closely in a looking-glass while the amount of light entering the eyes is
varied. Place yourself before a looking-glass and with your face to the
window. Probably the iris will be expanded, and there will only be a very
small opening or pupil in the center. Now shut one eye suddenly, while
narrowly watching the other in the glass all the time. At the moment the
light is cut off from one eye, the iris of the other contracts or is drawn
up so as to enlarge the pupil. This shows that there is a remarkable
interdependence between the curtains of the two eyes, as well as that they
are affected by variations in the quantity of light falling on them.

Perhaps one of the most interesting ways of watching the movements of
these sympathetic eye curtains is one which may be followed while you are
out walking on the street some dark winter night. A gas lamp seen at a
distance is, comparatively speaking, a point of light, with bars of light
emanating from it in many directions. These bars, which give the peculiar
spoked appearance to a star, are probably formed by optical defects of the
lens within the eye, or by the tear fluid on the exterior surface of the
eye, or by a combination of all these causes. Be that as it may, the
lengths of the spokes of light are limited by the inner margin of the eye
curtain; if the curtain be drawn up, then the spokes are long; if the
curtain be let down, or, in other words, if the pupil be very small and
contracted, then one can not see any spokes at all. Hence, as I look at a
distant gaslight, with its radiating golden spokes, I am looking at
something which will give me a sure indication of any movements of the eye
curtains. I strike a match and allow its light to fall into the eyes; the
spokes of the distant gas lamp have retreated into the point of flame as
if by magic; as I take the burning match away from before my eyes, the
spokes of the gas-lamp venture forth again. The experiment may be utilized
to see how much light is required to move the window curtains of the eyes.
Suppose you are walking toward two gas lamps, A and B; B about fifty yards
behind A. If you steadfastly look at B and at the golden spokes apparently
issuing from it, you may make these spokes a test of how soon the light of
A will move your iris. As you gradually approach A, you come at last to a
position where its light is strong enough to make the spokes of B begin to
shorten; a little nearer still and they vanish altogether. I have found
that about a third of the light which is competent to contract the pupil
very markedly will serve to commence its movement.--WILLIAM ACKROYD.

PURKINJE'S FIGURES (p. 222).--Stand in a dark room with a lighted candle
in hand. Shutting the left, hold the candle very near the right eye,
within three or four inches, obliquely outward and forward, so that the
light shall strongly illuminate the retina. Now move the light about
gently, upward, downward, back and forth, while you gaze intently on the
wall opposite. Presently the field of view becomes dark from the intense
impression of the light, and then, as you move the light about, there
appears projected on the wall and covering its whole surface, a shadowy,
ghost-like image, like a branching, leafless tree, or like a great
bodiless spider with many branching legs. What is it? It is an exact but
enlarged image of the _blood vessels of the retina_. These come in at
the entrance of the optic nerve, ramify in the middle layer, and therefore
in the strong light cast their shadows on the bacillary layer of the
retina. The impression of these shadows is projected outward into the
field of view, and seen there as an enlarged shadowy image. These have
been called Purkinje's Figures, from the discoverer.--PROF. JOSEPH LE
CONTE, _in Sight_.




XI.


APPENDIX.

QUESTIONS FOR CLASS USE.

_The questions include the Notes and the Selected Readings. The figures
refer to the pages_.

INTRODUCTION.

Illustrate the value of physiological knowledge. Why should physiology be
studied in youth? When are our habits formed? How do habits help us? Why
should children prize the lessons of experience? How does Nature punish a
violation of her laws? Name some of Nature's laws. What is the penalty of
their violation? Name some bad habits and their punishments. Some good
habits and their rewards. How do the young ruin their health? Compare
one's constitution with a deposit in the bank. Can one in youth lay up
health as he can money for middle or old age? Is not the preservation of
one's health a moral duty? What is suicide?

THE SKELETON.

3. How many bones are there in the body? Is the number fixed? Is the
length of the different bones proportional? What is an organ? A function?
Name the three uses of the bones. Why do the bones have such different
shapes?

4. Why are certain bones hollow? Round? Illustrate. Compare the resisting
property of bone with that of solid oak. What is the composition of bone?
How does it vary? How can you remove the mineral matter? The animal
matter? Why is a burned bone white and porous? What food do dogs find in
bones?

5. What is the use of each of the constituents of a bone? What is
"boneblack"? What is ossification? Why are not the bones of children as
easily broken as those of aged persons? Why do they unite so much quicker?
What are the fontanelles?

6. Describe the structure of a bone. What is the object of the filling?
Why does the amount vary in different parts of a bone? What is the
appearance of a bone seen through a microscope?

7. What is the periosteum? Is a bone once removed ever restored? What are
the lacunæ? The Haversian canals? Why so called? _Ans_. From their
discoverer, Havers. Define a bone. [Footnote: Bone structure may be
summarized as follows: A bone is a collection of _Haversian
elements_, or rods. An Haversian element consists of a tube surrounded
by _lamellæ_, which contain _lacunæ_, connected by _canaliculi_.--DR.
T. B. STOWELL.] What occupies the lacunæ? _Ans_. The bone cells
(osteoblasts). How do bones grow?

8. Illustrate. How does a broken bone heal? How rapidly is bone produced?
Illustrate. Objects of "splints"? Describe how a joint is packed.
Lubricated.

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