A Practical Physiology
Albert F. Blaisdell
Part 7 out of 9
be brought so closely together that the space becomes a mere slit. Air
forced through the slit will throw the edges of the folds into vibration
and a sound will be produced.
The Variations in the form of the opening will determine the variations in
the sound. Now, if the various muscles of the larynx be relaxed, the
opening of the glottis is wider. Thus the air enters and leaves the larynx
during breathing, without throwing the cords into vibration enough to
produce any sound.
We may say that the production of the voice is effected by an arrangement
like that of some musical instruments, the sounds produced by the
vibrations of the vocal cords being modified by the tubes above and below.
All musical sounds are due to movements or vibrations occurring with a
certain regularity, and they differ in loudness, pitch, and quality.
Loudness of the sound depends upon the extent of the vibrations, pitch on
the rapidity of the vibrations, and quality on the admixture of tones
produced by vibrations of varying rates of rapidity, related to one
[Illustration: Fig. 151.--Longitudinal Section of the Larynx. (Showing the
B, section of hyoid bone;
C, superior vocal cord;
D, ventricle of the larynx;
E, inferior vocal cord;
F, section of the thyroid cartilage;
H, section of anterior portion of the cricoid cartilage;
L, section of the posterior portion of the cricoid cartilage;
M, arytenoid cartilage;
N, section of the arytenoid muscle.
353. Factors in the Production of the Voice. Muscles which pass from
the cricoid cartilage to the outer angle of the arytenoids act to bring
the vocal cords close together, and parallel to one another, so that the
space between them is narrowed to a slit. A strong expiration now drives
the air from the lungs through the slit, between the cords, and throws
them into vibration. The vibration is small in amount, but very rapid.
Other muscles are connected with the arytenoid cartilages which serve to
seperate the vocal cords and to widely open the glottis. The force of the
outgoing current of air determines the extent of the movement of the
cords, and thus the loudness of the sound will increase with greater force
We have just learned that the pitch of sound depends on the rapidity of
the vibrations. This depends on the length of cords and their tightness
for the shorter and tighter a string is, the higher is the note which its
vibration produces. The vocal cords of women are about one-third shorter
than those of men, hence the higher pitch of the notes they produce. In
children the vocal cords are shorter than in adults. The cords of
tenor singers are also shorter than those of basses and baritones. The
muscles within the larynx, of course, play a very important part in
altering the tension of the vocal cords. Those qualities of the voice
which we speak of as sweet, harsh, and sympathetic depend to a great
extent upon the peculiar structure of the vocal cords of the individual.
Besides the physical condition of the vocal cords, as their degree of
smoothness, elasticity, thickness, and so on, other factors determine the
quality of an individual's voice. Thus, the general shape and structure of
the trachea, the larynx, the throat, and mouth all influence the quality
of voice. In fact, the air passages, both below and above the vibrating
cords, act as resonators, or resounding chambers, and intensify and modify
the sounds produced by the cords. It is this fact that prompts skillful
teachers of music and elocution to urge upon their pupils the necessity of
the mouth being properly opened during speech, and especially during
Experiment 187. _To show the anatomy of the throat_. Study the
general construction of the throat by the help of a hand mirror. Repeat
the same on the throat of some friend.
Experiment 188. _To show the construction of the vocal organs_. Get
a butcher to furnish two windpipes from a sheep or a calf. They differ
somewhat from the vocal organs of the human body, but will enable us to
recognize the different parts which have been described, and thus to get
a good idea of the gross anatomy.
One specimen should be cut open lengthwise in the middle line in front,
and the other cut in the same way from behind.
354. Speech. Speech is to be distinguished from voice. It may exist
without voice, as in a whisper. Speech consists of articulated
sounds, produced by the action of various parts of the mouth, throat, and
nose. Voice is common to most animals, but speech is the peculiar
privilege of man.
[Illustration: Fig. 152.--Diagramatic Horizontal Section of Larynx to show
the Direction of Pull of the Posterior Crico-Arytenoid Muscles, which
abduct the Vocal Cords. (Dotted lines show position in abduction.)]
The organ of speech is perhaps the most delicate and perfect _motor_
apparatus in the whole body. It has been calculated that upwards of 900
movements per minute can be made by the movable organs of speech during
reading, speaking, and singing. It is said that no less than a hundred
different muscles are called into action in talking. Each part of this
delicate apparatus is so admirably adjusted to every other that all parts
of this most complex machinery act in perfect harmony.
There are certain articulate sounds called vowel or vocal, from the fact
that they are produced by the vocal cords, and are but slightly modified
as they pass out of the mouth. The true vowels, _a, e, i, o, u_, can
all be sounded alone, and may be prolonged in expiration. These are the
sounds chiefly used in singing. The differences in their characters are
produced by changes in the position of the tongue, mouth, and lips.
Consonants are sounds produced by interruptions of the outgoing
current of air, but in some cases have no sound in themselves, and serve
merely to modify vowel sounds. Thus, when the interruption to the outgoing
current takes place by movements of the lips, we have the _labial_
consonants, _p_, _b_, _f_, and _v_. When the tongue, in relation with the
teeth or hard palate, obstructs the air, the _dental_ consonants, _d_,
_t_, _l_, and _s_ are produced. _Gutturals_, such as _k_, _g_, _ch_, _gh_,
and _r_, are due to the movements of the root of the tongue in connection
with the soft palate or pharynx.
To secure an easy and proper production of articulate sounds, the mouth,
teeth, lips, tongue, and palate should be in perfect order. The
modifications in articulation occasioned by a defect in the palate, or in
the uvula, by the loss of teeth, from disease, and from congenital
defects, are sufficiently familiar. We have seen that speech consists
essentially in a modification of the vocal sounds by the accessory organs,
or by parts above the larynx, the latter being the essential vocal
Many animals have the power of making articulated sounds; a few have
risen, like man, to the dignity of sentences, but these are only by
imitation of the human voice. Both vowels and consonants can be
distinguished in the notes of birds, the vocal powers of which are
generally higher than those of mammals. The latter, as a rule, produce
only vowels, though some are also able to form consonants.
Persons idiotic from birth are incapable of producing any other vocal
sounds than inarticulate cries, although supplied with all the internal
means of articulation. Persons deaf and dumb are in the same situation,
though from a different cause; the one being incapable of imitating, and
the other being deprived of hearing the sounds to be imitated.
[Illustration: Fig. 153.--Direction of Pull of the Lateral
Crico-Arytenoids, which adduct the Vocal Cords. (Dotted lines show
position in adduction.)]
In _whispering_, the larynx takes scarcely any part in the production of
the sounds; the vocal cords remain apart and comparatively slack, and the
expiratory blast rushes through without setting them in vibration.
In _stammering_, spasmodic contraction of the diaphragm interrupts the
effort of expiration. The stammerer has full control of the mechanism of
articulation, but not of the expiratory blast. His larynx and his lips are
at his command, but not his diaphragm. To conquer this defect he must
train his muscles of respiration to calm and steady action during speech.
The _stutterer_, on the other hand, has full control of the muscles of
expiration. His diaphragm is well drilled, but his lips and tongue are
355. The Care of the Throat and Voice. The throat, exposed as it is
to unwholesome and overheated air, irritating dust of the street,
factories, and workshops, is often inflamed, resulting in that common
ailment, _sore throat_. The parts are red, swollen, and quite painful on
swallowing. Speech is often indistinct, but there is no hoarseness or
cough unless the uvula is lengthened and tickles the back part of the
tongue. Slight sore throat rarely requires any special treatment, aside
from simple nursing.
The most frequent cause of throat trouble is the action of cold upon the
heated body, especially during active perspiration. For this reason a cold
bath should not be taken while a person is perspiring freely. The muscles
of the throat are frequently overstrained by loud talking, screaming,
shouting, or by reading aloud too much. People who strain or misuse the
voice often suffer from what is called "clergyman's sore throat." Attacks
of sore throat due to improper methods of breathing and of using the voice
should be treated by judicious elocutionary exercises and a system of
vocal gymnastics, under the direction of proper teachers.
Persons subject to throat disease should take special care to wear
suitable underclothing, adapted to the changes of the seasons. Frequent
baths are excellent tonics to the skin, and serve indirectly to protect
one liable to throat ailments from changes in the weather. It is not
prudent to muffle the neck in scarfs, furs, and wraps, unless perhaps
during an unusual exposure to cold. Such a dress for the neck only makes
the parts tender, and increases the liability to a sore throat.
Every teacher of elocution or of vocal music, entrusted with the training
of a voice of some value to its possessor, should have a good, practical
knowledge of the mechanism of the voice. Good voices are often injured by
injudicious management on the part of some incompetent instructor. It is
always prudent to cease speaking or singing in public the moment there is
any hoarseness or sore throat.
The voice should not be exercised just after a full meal, for a full
stomach interferes with the free play of the diaphragm. A sip of water
taken at convenient intervals, and held in the mouth for a moment or two,
will relieve the dryness of the throat during the use of the voice.
356. Effect of Alcohol upon the Throat and Voice. Alcoholic beverages
seriously injure the throat, and consequently the voice, by causing a
chronic inflammation of the membrane lining the larynx and the vocal
cords. The color is changed from the healthful pink to red, and the
natural smooth surface becomes roughened and swollen, and secretes a tough
The vocal cords usually suffer from this condition. They are thickened,
roughened, and enfeebled, the delicate vibration of the cords is impaired,
the clearness and purity of the vocal tones are gone, and instead the
voice has become rough and husky. So well known is this result that
vocalists, whose fortune is the purity and compass of their tones, are
scrupulously careful not to impair these fine qualities by convivial
357. Effect of Tobacco upon the Throat and Voice. The effect of
tobacco is often specially serious upon the throat, producing a disease
well known to physicians as "the smoker's sore throat." Still further, it
produces inflammation of the larynx, and thus entails disorders of the
vocal cords, involving rough voice and harsh tones. For this reason
vocalists rarely allow themselves to come under the narcotic influence of
tobacco smoke. It is stated that habitual smokers rarely have a normal
condition of the throat.
Experiment 189. _To illustrate the importance of the resonating
cavity of the nose in articulation_. Pinch the nostrils, and try to
pronounce slowly the words "Lincoln," "something," or any other words
which require the sound of _m_, _ln_, or _ng_.
[Illustration: Fig. 154.]
Experiment 190. _To illustrate the passage of air through the
glottis._ Take two strips of India rubber, and stretch them over the
open end of a boy's "bean-blower," or any kind of a tube. Tie them
tightly with thread, so that a chink will be left between them, as shown
in Fig. 154. Force the air through such a tube by blowing hard, and if
the strips are not too far apart a sound will be produced. The sound
will vary in character, just as the bands are made tight or loose.
Experiment 191. "A very good illustration of the action of the
vocal bands in the production of the voice may be given by means of a
piece of bamboo or any hollow wooden tube, and a strip of rubber, about
an inch or an inch and a half wide, cut from the pure sheet rubber used
"One end of the tube is to be cut sloping in two directions, and the
strip of sheet rubber is then to be wrapped round the tube, so as to
leave a narrow slit terminating at the upper corners of the tube.
"By blowing into the other end of the tube the edges of the rubber bands
will be set in vibration, and by touching the vibrating membrane at
different points so as to check its movements it may be shown that the
pitch of the note emitted depends upon the length and breadth of the
vibrating portion of the vocal bands."--Dr. H. P. Bowditch.
[NOTE. The limitations of a text-book on physiology for schools do not
permit so full a description of the voice as the subject deserves. For
additional details, the student is referred to Cohen's _The Throat and
the Voice_, a volume in the "American Health Primer Series." Price 40
Accidents and Emergencies.
358. Prompt Aid to the Injured. A large proportion of the accidents,
emergencies, and sudden sicknesses that happen do not call for medical or
surgical attention. For those that do require the services of a physician
or surgeon, much can be often done before the arrival of professional
help. Many a life has been saved and much suffering and anxiety prevented
by the prompt and efficient help of some person with a cool head, a steady
hand, and a practical knowledge of what to do first. Many of us can recall
with mingled admiration and gratitude the prompt services rendered our
families by some neighbor or friend in the presence of an emergency or
In fact, what we have studied in the preceding chapters becomes tenfold
more interesting, instructive, and of value to us, if we are able to
supplement such study with its practical application to the treatment of
the more common and less serious accidents and emergencies.
While no book can teach one to have presence of mind, a cool head, or to
restrain a more or less excitable temperament in the midst of sudden
danger, yet assuredly with proper knowledge for a foundation, a certain
self-confidence may be acquired which will do much to prevent hasty
action, and to maintain a useful amount of self-control.
Space allows us to describe briefly in this chapter only a few of the
simplest helps in the more common accidents and emergencies
which are met with in everyday life.
359. Hints as to what to Do First. Retain so far as possible your
presence of mind, or, in other words, keep cool. This is an all-important
direction. Act promptly and quietly, but not with haste. Whatever you do,
do in earnest; and never act in a half-hearted manner in the presence of
danger. Of course, a knowledge of what to-do and how to do it will
contribute much towards that self-control and confidence that command
success. Be sure and send for a doctor at once if the emergency calls for
skilled service. All that is expected of you under such circumstances
is to tide over matters until the doctor comes.
[Illustration: Fig. 155.--Showing how Digital Compression should be
applied to the Brachial Artery.]
Do not presume upon any smattering of knowledge you have, to assume any
risk that might lead to serious results. Make the sufferer comfortable by
giving him an abundance of fresh air and placing him in a restful
position. Do all that is possible to keep back the crowd of curious
lookers-on, whom a morbid curiosity has gathered about the injured person.
Loosen all tight articles of clothing, as belts, collars, corsets, and
elastics. Avoid the use of alcoholic liquors. They are rarely of any real
service, and in many instances, as in bleeding, may do much harm.
360. Incised and Lacerated Wounds. An incised or cut wound
is one made by a sharp instrument, as when the finger is cut with a
knife. Such a wound bleeds freely because the clean-cut edges do not favor
the clotting of blood. In slight cuts the bleeding readily ceases, and the
wound heals by primary union, or by "first intention," as surgeons call
Lacerated and contused wounds are made by a tearing or bruising
instrument, for example, catching the finger on a nail. Such wounds bleed
but little, and the edges and surfaces are rough and ragged.
If the incised wound is deep or extensive, a physician is necessary to
bring the cut edges together by stitches in order to get primary union.
Oftentimes, in severe cuts, and generally in lacerations, there is a loss
of tissue, so that the wound heals by "second intention"; that is, the
wound heals from the bottom by a deposit of new cells called
_granulations_, which gradually fill it up. The skin begins to grow from
the edges to the center, covering the new tissue and leaving a cicatrix or
scar with which every one is familiar.
361. Contusion and Bruises. An injury to the soft tissues, caused by
a blow from some blunt instrument, or a fall, is a contusion, or
bruise. It is more or less painful, followed by discoloration due to
the escape of blood under the skin, which often may not be torn through. A
black eye, a knee injured by a fall from a bicycle, and a finger hurt by a
baseball, are familiar examples of this sort of injury. Such injuries
ordinarily require very simple treatment.
The blood which has escaped from the capillaries is slowly absorbed,
changing color in the process, from blue black to green, and fading into a
light yellow. Wring out old towels or pieces of flannel in hot water, and
apply to the parts, changing as they become cool. For cold applications,
cloths wet with equal parts of water and alcohol, vinegar, and witch-hazel
may be used. Even if the injury is apparently slight it is always safe to
rest the parts for a few days.
When wounds are made with ragged edges, such as those made by broken
glass and splinters, more skill is called for. Remove every bit of
foreign substance. Wash the parts clean with one of the many
antiseptic solutions, bring the torn edges together, and hold them in
place with strips of plaster. Do not cover such an injury all over with
plaster, but leave room for the escape of the wound discharges. For an
outside dressing, use compresses made of clean cheese-cloth or strips of
any clean linen cloth. The antiseptic _corrosive-sublimate gauze_ on sale
at any drug store should be used if it can be had.
Wounds made by toy pistols, percussion-caps, and rusty nails and tools, if
neglected, often lead to serious results from blood-poisoning. A hot
flaxseed poultice may be needed for several days. Keep such wounds clean
by washing or syringing them twice a day with hot _antiseptics_, which are
poisons to _bacteria_ and kill them or prevent their growth. Bacteria are
widely distributed, and hence the utmost care should be taken to have
everything which is to come in contact with a wounded surface free from
the germs of inflammation. In brief, such injuries must be kept
_scrupulously neat_ and _surgically clean_.
[Illustration: Fig. 156.--Dotted Line showing the Course of the Brachial
The injured parts should be kept at rest. Movement and disturbance hinder
the healing process.
362. Bites of Mad Dogs. Remove the clothing at once, if only from the
bitten part, and apply a temporary ligature _above_ the wound. This
interrupts the activity of the circulation of the part, and to that
extent delays the absorption of the poisonous saliva by the blood-vessels
of the wound. A dog bite is really a lacerated and contused wound, and
lying in the little roughnesses, and between the shreds, is the poisonous
saliva. If by any means these projections and depressions affording the
lodgment can be removed, the poison cannot do much harm. If done with a
knife, the wound would be converted, practically, into an incised wound,
and would require treatment for such.
If a surgeon is at hand he would probably cut out the injured portion, or
cauterize it thoroughly. Professional aid is not always at our command,
and in such a case it would be well to take a poker, or other suitable
piece of iron, heat it _red_ hot in the fire, wipe off and destroy the
entire surface of the wound. As fast as destroyed, the tissue becomes
white. An iron, even at a white heat, gives less pain and at once destroys
the vitality of the part with which it comes in contact.
If the wound is at once well wiped out, and a stick of solid nitrate of
silver (lunar caustic) rapidly applied to the entire surface of the wound,
little danger is to be apprehended. Poultices and warm fomentations should
be applied to the injury to hasten the sloughing away of the part whose
vitality has been intentionally destroyed.
Any dog, after having bitten a person, is apt, under a mistaken belief, to
be at once killed. This should not be done. There is no more danger from a
dog-bite, unless the dog is suffering from the disease called _rabies_ or
is "mad," than from any other lacerated wound. The suspected animal should
be at once placed in confinement and watched, under proper safeguards, for
the appearance of any symptoms that indicate rabies.
Should no pronounced symptoms indicate this disease in the dog, a great
deal of unnecessary mental distress and worry can be saved both on the
part of the person bitten and his friends.
363. Injuries to the Blood-vessels. It is very important to know the
difference between the bleeding from an artery and that from a vein.
If an artery bleeds, the blood leaps in spurts, and is of a
bright scarlet color.
If a vein bleeds, the blood flows in a steady stream, and is of a
dark purple color.
If the capillaries are injured the blood merely oozes.
Bleeding from an artery is a dangerous matter in proportion to the size of
the vessel, and life itself may be speedily lost. Hemorrhage from a vein
or from the capillaries is rarely troublesome, and is ordinarily easily
checked, aided, if need be, by hot water, deep pressure, the application
of some form of iron styptic, or even powdered alum. When an artery is
bleeding, always remember to make deep pressure between the wound and the
heart. In all such cases send at once for the doctor.
[Illustration: Fig. 157.--Showing how Digital Compression should be
applied to the Femoral Artery.]
Do not be afraid to act at once. A resolute grip in the right place with
firm fingers will do well enough, until a twisted handkerchief, stout
cord, shoestring, suspender, or an improvised tourniquet is ready to
take its place. If the flow of blood does not stop, change the pressure
until the right spot is found.
Sometimes it will do to seize a handful of dry earth and crowd it down
into the bleeding wound, with a firm pressure. Strips of an old
handkerchief, underclothing, or cotton wadding may also be used as a
compress, provided pressure is not neglected.
In the after-treatment it is of great importance that the wound and the
dressing should be kept free from bacteria by keeping everything
364. Where and how to Apply Pressure. The principal places in which
to apply pressure when arteries are injured and bleeding should always be
kept in mind.
Experiment 192. _How to tie a square knot_. If the student would
render efficient help in accidents and emergencies, to say nothing of
service on scores of other occasions, he must learn how to tie a square
or "reef" knot. This knot is secure and does not slip as does the
"granny" knot. The square knot is the one used by surgeons in ligating
vessels and securing bandages. Unless one knew the difference, the
insecure "granny" knot might be substituted.
[Illustration: Fig. 158.--Showing how a Square Knot may be tied with a
Cord and a Handkerchief.]
A square knot is tied by holding an end of a bandage or cord in
each hand, and then passing the end in the _right_ hand over the one in
the left and tying; the end now in the _left_ hand is passed over the
one in the right and again tied.
If in the finger, grasp it with the thumb and forefinger, and pinch
it firmly on each side; if in the hand, press on the bleeding spot,
or press with the thumb just above and in front of the wrist.
For injuries below the elbow, grasp the upper part of the arm with
the hands, and squeeze hard. The main artery runs in the middle line of
the bend of the elbow. Tie the knotted cord here, and bend the forearm so
as to press hard against the knot.
For the upper arm, press with the fingers against the bone on the
inner side, and just on the edge of the swell of the biceps muscle. Now we
are ready for the knotted cord. Take a stout stick of wood, about a foot
long, and twist the cord hard with it, bringing the knot firmly over the
For the foot or leg, pressure as before, in the hollow behind
the knee, just above the calf of the leg. Bend the thigh towards the
abdomen and bring the leg up against the thigh, with the knot in the bend
of the knee.
365. Bleeding from the Stomach and Lungs. Blood that comes from the
lungs is bright red, frothy, or "soapy." There is rarely much; it usually
follows coughing, feels warm, and has a salty taste. This is a grave
symptom. Perfect rest on the back in bed and quiet must be insisted upon.
Bits of ice should be eaten freely. Loosen the clothing, keep the
shoulders well raised, and the body in a reclining position and absolutely
at rest. Do not give alcoholic drinks.
Blood from the stomach is not frothy, has a sour taste, and is
usually dark colored, looking somewhat like coffee grounds. It is more in
quantity than from the lungs, and is apt to be mixed with food. Employ the
same treatment, except that the person should be kept flat on the back.
366. Bleeding from the Nose. This is the most frequent and the least
dangerous of the various forms of bleeding. Let the patient sit upright;
leaning forward with the head low only increases the hemorrhage. Raise the
arm on the bleeding side; do not blow the nose. Wring two towels out of
cold water; wrap one around the neck and the other properly folded over
the forehead and upper part of the nose.
Add a teaspoonful of powdered _alum_ to a cup of water, and snuff it up
from the hand. If necessary, soak in alum water a piece of absorbent
cotton, which has been wound around the pointed end of a pencil or
penholder; plug the nostril by pushing it up with a twisting motion until
367. Burns or Scalds. Burns or scalds are dangerous in proportion to
their extent and depth. A child may have one of his fingers burned off
with less danger to life than an extensive scald of his back and legs. A
deep or extensive burn or scald should always have prompt medical
In burns by acids, bathe the parts with an alkaline fluid, as diluted
ammonia, or strong soda in solution, and afterwards dress the burn.
In burns caused by lime, caustic potash, and other alkalies, soak the
parts with vinegar diluted with water; lemon juice, or any other diluted
Remove the clothing with the greatest care. Do not pull, but carefully cut
and coax the clothes away from the burned places. Save the skin unbroken
if possible, taking care not to break the blisters. The secret of
treatment is to prevent friction, and to keep out the air. If
the burn is slight, put on strips of soft linen soaked in a strong
solution of baking-soda and water, one heaping table spoonful to a cupful
of water. This is especially good for scalds.
[Illustration: Fig. 159.--Dotted Line showing the Course of the Femoral
_Carron oil_ is one of the best applications. It is simply half
linseed-oil and half lime-water shaken together. A few tablespoonfuls of
carbolic acid solution to one pint may be added to this mixture to help
deaden the pain. Soak strips of old linen or absorbent cotton in this
time-honored remedy, and gently apply.
If carbolized or even plain _vaseline_ is at hand, spread it freely on
strips of old linen, and cover well the burnt parts, keeping out the air
with other strips carefully laid on. Simple cold water is better than
flour, starch, toilet powder, cotton batting, and other things which are
apt to stick, and make an after-examination very painful.
[Illustration: Fig. 160.--Showing how Hemorrhage from the Femoral Artery
may be arrested by the Use of an Improvised Apparatus (technically called
368. Frost Bites. The ears, toes, nose, and fingers are occasionally
frozen, or frost-bitten. No warm air, warm water, or fire should be
allowed near the frozen parts until the natural temperature is nearly
restored. Rub the frozen part vigorously with snow or snow-water in a cold
room. Continue this until a burning, tingling pain is felt, when all
active treatment should cease.
Pain shows that warmth and circulation are beginning to return. The after
effects of a frost bite are precisely like those of a burn, and require
similar treatment. Poultices made from scraped raw potatoes afford much
comfort for an after treatment.
369. Catching the Clothing on Fire. When the clothing catches fire,
throw the person down on the ground or floor, as the flames will tend
less to rise toward the mouth and nostrils. Then without a moment's delay,
roll the person in a carpet or hearth-rug, so as to stifle the flames,
leaving only the head out for breathing.
If no carpet or rug can be had, then take off your coat, shawl, or cloak
and use it instead. Keep the flame as much as possible from the face, so
as to prevent the entrance of the hot air into the lungs. This can be done
by beginning at the neck and shoulders with the wrapping.
370. Foreign Bodies in the Throat. Bits of food or other small
objects sometimes get lodged in the throat, and are easily extracted by
the forefinger, by sharp slaps on the back, or expelled by vomiting. If it
is a sliver from a toothpick, match, or fishbone, it is no easy matter to
remove it; for it generally sticks into the lining of the passage. If the
object has actually passed into the windpipe, and is followed by sudden
fits of spasmodic coughing, with a dusky hue to the face and fingers,
surgical help must be called without delay.
If a foreign body, like coins, pencils, keys, fruit-stones, etc., is
swallowed, it is not wise to give a physic. Give plenty of hard-boiled
eggs, cheese, and crackers, so that the intruding substance maybe enfolded
in a mass of solid food and allowed to pass off in the natural way.
371. Foreign Bodies in the Nose. Children are apt to push beans,
peas, fruit-stones, buttons, and other small objects, into the nose.
Sometimes we can get the child to help by blowing the nose hard. At other
times, a sharp blow between the shoulders will cause the substance to fall
out. If it is a pea or bean, which is apt to swell with the warmth and
moisture, call in medical help at once.
372. Foreign Bodies in the Ear. It is a much more difficult matter to
get foreign bodies out of the ear than from the nose. Syringe in a little
warm water, which will often wash out the substance. If live insects get
into the ear, drop in a little sweet oil, melted vaseline, salt and water,
or even warm molasses.
If the tip of the ear is pulled up gently, the liquid will flow in more
readily. If a light is held close to the outside ear, the insect may be
coaxed to crawl out towards the outer opening of the ear, being attracted
by the bright flame.
373. Foreign Bodies in the Eye. Cinders, particles of dust, and other
small substances, often get into the eye, and cause much pain. It will
only make bad matters worse to rub the eye. Often the copious flow of
tears will wash the substance away. It is sometimes seen, and removed
simply by the twisted corner of a handkerchief carefully used. If it is
not removed, or even found, in this way, the upper lid must be turned
[Illustration: Fig. 161.--Showing how the Upper Eyelid may be everted with
a Pencil or Penholder.]
This is done usually as follows: Seize the lashes between the thumb and
forefinger, and draw the edge of the lid away from the eyeball. Now,
telling the patient to look down, press a slender lead-pencil or penholder
against the lid, parallel to and above the edge, and then pull the edge
up, and turn it over the pencil by means of the lashes.
The eye is now readily examined, and usually the foreign body is easily
seen and removed. Do not increase the trouble by rubbing the eye after you
fail, but get at once skilled help. After the substance has been removed,
bathe the eye for a time with hot water.
If lime gets into the eye, it may do a great amount of mischief, and
generally requires medical advice, or permanent injury will result. Until
such advice can be had, bathe the injured parts freely with a weak
solution of vinegar and hot water.
374. Broken Bones. Loss of power, pain, and swelling are symptoms of
a broken bone that may be easily recognized. Broken limbs should always be
handled with great care and tenderness. If the accident happens in the
woods, the limb should be bound with handkerchiefs, suspenders, or strips
of clothing, to a piece of board, pasteboard, or bark, padded with moss or
grass, which will do well enough for a temporary splint. Always put a
broken arm into a sling after the splints are on.
[Illustration: Fig. 162.--Showing how an Umbrella may be used as a
Temporary Splint in Fracture of the Leg.]
Never move the injured person until the limb is made safe from further
injuries by putting on temporary splints. If you do not need to move the
person, keep the limb in a natural, easy position, until the doctor comes.
Remember that this treatment for broken bones is only to enable the
patient to be moved without further injury. A surgeon is needed at once to
set the broken bone.
[Illustration: Fig. 163.--Showing how a Pillow may be used as a Temporary
Splint in Fracture of the Leg.]
375. Fainting. A fainting person should be laid flat at once. Give
plenty of fresh air, and dash cold water, if necessary, on the head and
neck. Loosen all tight clothing. Smelling-salts may be held to the nose,
to excite the nerves of sensation.
376. Epileptic and Hysterical Fits, Convulsions of Children.
Sufferers from "fits" are more or less common. In _epilepsy_, the sufferer
falls with a peculiar cry; a loss of consciousness, a moment of rigidity,
and violent convulsions follow. There is foaming at the mouth, the eyes
are rolled up, and the tongue or lips are often bitten. When the fit is
over the patient remains in a dazed, stupid state for some time. It is a
mistake to struggle with such patients, or to hold them down and keep them
quiet. It does more harm than good.
See that the person does not injure himself; crowd a pad made from a
folded handkerchief or towel between the teeth, to prevent biting of the
lips or tongue. Do not try to make the sufferer swallow any drink.
Unfasten the clothes, especially about the neck and chest. Persons who are
subject to such fits should rarely go out alone, and never into crowded or
excited gatherings of any kind.
_Hysterical fits_ almost always occur in young women. Such patients never
bite their tongue nor hurt themselves. Placing a towel wrung out in cold
water across the face, or dashing a little cold water on the face or
neck, will usually cut short the fit, speaking firmly to the patient at
the same time. Never sympathize too much with such patients; it will only
make them a great deal worse.
377. Asphyxia. Asphyxia is from the Greek, and means an "absence of
pulse." This states a fact, but not the cause. The word is now commonly
used to mean _suspended animation_. When for any reason the proper supply
of oxygen is cut off, the tissues rapidly load up with carbon dioxid. The
blood turns dark, and does not circulate. The healthy red or pink look of
the lips and finger-nails becomes a dusky purple. The person is suffering
from a lack of oxygen; that is, from asphyxia, or suffocation.
It is evident there can be several varieties of asphyxia, as in apparent
drowning, strangulation and hanging, inhalation of gases, etc.
The first and essential thing to do is to give fresh air. Remove the
person to the open air and place him on his back. Remove tight clothing
about the throat and waist, dash on cold water, give a few drops of
ammonia in hot water or hot ginger tea. Friction applied to the limbs
should be kept up. If necessary, use artificial respiration by the
Sylvester method (sec. 380).
The chief dangers from poisoning by noxious gases come from the fumes of
burning coal in the furnace, stove, or range; from "blowing out" gas,
turning it down, and having it blown out by a draught; from the foul air
often found in old wells; from the fumes of charcoal and the foul air of
378. Apparent Drowning. Remove all tight clothing from the neck,
chest, and waist. Sweep the forefinger, covered with a handkerchief or
towel, round the mouth, to free it from froth and mucus. Turn the body on
the face, raising it a little, with the hands under the hips, to allow any
water to run out from the air passages. Take only a moment for this.
Lay the person flat upon the back, with a folded coat, or pad of any
kind, to keep the shoulders raised a little. Remove all the wet, clinging
clothing that is convenient. If in a room or sheltered place, strip the
body, and wrap it in blankets, overcoats, etc. If at hand, use bottles of
hot water, hot flats, or bags of hot sand round the limbs and feet. Watch
the tongue: it generally tends to slip back, and to shut off the air from
the glottis. Wrap a coarse towel round the tip of the tongue, and keep it
well pulled forward.
The main thing to do is to keep up artificial respiration until the
natural breathing comes, or all hope is lost. This is the simplest way to
do it: The person lies on the back; let some one kneel behind the head.
Grasp both arms near the elbows, and sweep them upward above the head
until they nearly touch. Make a firm pull for a moment. This tends to fill
the lungs with air by drawing the ribs up, and making the chest cavity
larger. Now return the arms to the sides of the body until they press hard
against the ribs. This tends to force out the air. This makes artificially
a complete act of respiration. Repeat this act about fifteen times every
[Illustration: Fig. 164.--The Sylvester Method. (First
All this may be kept up for several hours. The first sign of recovery is
often seen in the slight pinkish tinge of the lips or finger-nails. That
the pulse cannot be felt at the wrist is of little value in itself as a
sign of death. Life may be present when only the most experienced ear can
detect the faintest heart-beat.
When a person can breathe, even a little, he can swallow. Hold
smelling-salts or hartshorn to the nose. Put one teaspoonful of the
aromatic spirits of ammonia, or even of ammonia water, into a half-glass
of hot water, and give a few teaspoonfuls of this mixture every few
minutes. Meanwhile do not fail to keep up artificial warmth in the most
379. Methods of Artificial Respiration. There are several
well-established methods of artificial respiration. The two known as the
Sylvester and the Marshall Hall methods are generally accepted
as efficient and practical.
[Illustration: Fig. 165.--The Sylvester Method. (Second
380. The Sylvester Method. The water and mucus are supposed to have
been removed from the interior of the body by the means above described
The patient is to be placed on his back, with a roll made of a coat or a
shawl under the shoulders; the tongue should then be drawn forward and
retained by a handkerchief which is placed across the extended organ and
carried under the chin, then crossed and tied at the back of the neck. An
elastic band or small rubber tube or a suspender may be used for the same
The attendant should kneel at the head and grasp the elbows of the
patient and draw them upward until the hands are carried above the head
and kept in this position until one, two, three, can be slowly counted.
This movement elevates the ribs, expands the chest, and creates a vacuum
in the lungs into which the air rushes, or in other words, the movement
produces _inspiration_. The elbows are then slowly carried downward,
placed by the side, and pressed inward against the chest, thereby
diminishing the size of the latter and producing _expiration_.
These movements should be repeated about fifteen times each minute for at
least two hours, provided no signs of animation show themselves.
381. The Marshall Hall Method. The patient should be placed face
downwards, the head resting on the forearm with a roll or pillow placed
under the chest; he should then be turned on his side, an assistant
supporting the head and keeping the mouth open; after an interval of two
or three seconds, the patient should again be placed face downward and
allowed to remain in this position the same length of time. This operation
should be repeated fifteen or sixteen times each minute, and continued
(unless the patient recovers) for at least two hours.
[Illustration: Fig. 166.--The Marshall Hall Method. (First position.)]
If, after using one of the above methods, evidence of recovery appears,
such as an occasional gasp or muscular movement, the efforts to produce
artificial respiration must not be discontinued, but kept up until
respiration is fully established. All wet clothing should then be removed,
the patient rubbed dry, and if possible placed in bed, where warmth and
warm drinks can be properly administered. A small amount of nourishment,
in the form of hot milk or beef tea, should be given, and the patient kept
quiet for two or three days.
[Illustration: Fig. 167.--The Marshall Hall Method. (Second position.)]
382. Sunstroke or Heatstroke. This serious accident, so far-reaching
oftentimes in its result, is due to an unnatural elevation of the bodily
temperature by exposure to the direct rays of the sun, or from the extreme
heat of close and confined rooms, as in the cook-rooms and laundries of
hotel basements, from overheated workshops, etc.
There is sudden loss of consciousness, with deep, labored breathing, an
intense burning heat of the skin, and a marked absence of sweat. The main
thing is to lower the temperature. Strip off the clothing; apply chopped
ice, wrapped in flannel to the head. Rub ice over the chest, and place
pieces under the armpits and at the sides. If there is no ice, use sheets
or cloths wet with cold water. The body may be stripped, and sprinkled
with ice-water from a common watering-pot.
If the skin is cold, moist, or clammy, the trouble is due to heat
exhaustion. Give plenty of fresh air, but apply no cold to the body. Apply
heat, and give hot drinks, like hot ginger tea. Sunstroke or heatstroke is
a dangerous affliction. It is often followed by serious and permanent
results. Persons who have once suffered in this way should carefully avoid
any risk in the future.
In Sickness and in Health.
383. Arrangement of the Sick-room. This room, if possible, should be
on the quiet and sunny side of the house. Pure, fresh air, sunshine, and
freedom from noise and odor are almost indispensable. A fireplace as a
means of ventilation is invaluable. The bed should be so placed that the
air may get to it on all sides and the nurse move easily around it.
Screens should be placed, if necessary, so as to exclude superfluous light
The sick-room should be kept free from all odors which affect the sick
unpleasantly, as perfumery, highly scented soaps, and certain flowers.
Remove all useless ornaments and articles likely to collect dust, as
unnecessary pieces of furniture and heavy draperies. A clean floor, with a
few rugs to deaden the footsteps, is much better than a woolen carpet.
Rocking-chairs should be banished from the sick-room, as they are almost
sure to disturb the sick.
A daily supply of fresh flowers tends to brighten the room. Keep the
medicines close at hand, but all poisonous drugs should be kept carefully
by themselves and ordinarily under lock and key. A small table should be
placed at the bedside, and on it the bell, food tray, flowers and other
small things which promote the comfort of the patient.
The nurse should not sleep with the patient. Sofas and couches are not
commonly comfortable enough to secure needed rest. A cot bed is at once
convenient and inexpensive, and can be readily folded and put out of sight
in the daytime. It can also be used by the patient occasionally,
especially during convalescence.
384. Ventilation of the Sick-room. Proper ventilation is most
essential to the sick-room, but little provision is ordinarily made for so
important a matter. It is seldom that one of the windows cannot be let
down an inch or more at the top, a screen being arranged to avoid any
draught on the patient. Remove all odors by ventilation and not by
spraying perfumery, or burning pastilles, which merely conceal offensive
odors without purifying the air. During cold weather and in certain
diseases, the patient may be covered entirely with blankets and the
windows opened wide for a few minutes.
Avoid ventilation by means of doors, for the stale air of the house,
kitchen smells, and noises made by the occupants of the house, are apt to
reach the sick-room. The entire air of the room should be changed at least
two or three times a day, in addition to the introduction of a constant
supply of fresh air in small quantities.
385. Hints for the Sick-room. Always strive to look cheerful and
pleasant before the patient. Whatever may happen, do not appear to be
annoyed, discouraged, or despondent. Do your best to keep up the courage
of sick persons under all circumstances. In all things keep in constant
mind the comfort and ease of the patient.
Do not worry the sick with unnecessary questions, idle talk, or silly
gossip. It is cruel to whisper in the sick-room, for patients are always
annoyed by it. They are usually suspicious that something is wrong and
generally imagine that their condition has changed for the worse.
Symptoms of the disease should never be discussed before the patient,
especially if he is thought to be asleep. He may be only dozing, and any
such talk would then be gross cruelty. Loud talking must, of course, be
avoided. The directions of the physician must be rigidly carried out in
regard to visitors in the sick-room. This is always a matter of foremost
importance, for an hour or even a night of needed sleep and rest may be
lost from the untimely call of some thoughtless visitor. A competent
nurse, who has good sense and tact, should be able to relieve the family
of any embarrassment under such circumstances.
Do not ever allow a kerosene light with the flame turned down to remain in
the sick-room. Use the lamp with the flame carefully shaded, or in an
adjoining room, or better still, use a sperm candle for a night light.
Keep, so far as possible, the various bottles of medicine, spoons,
glasses, and so on in an adjoining room, rather than to make a formidable
array of them on a bureau or table near the sick-bed. A few simple things,
as an orange, a tiny bouquet, one or two playthings, or even a pretty
book, may well take their place.
The ideal bed is single, made of iron or brass, and provided with woven
wire springs and a hair mattress. Feather-beds are always objectionable in
the sick-room for many and obvious reasons. The proper making of a
sick-bed, with the forethought and skill demanded in certain diseases, is
of great importance and an art learned only after long experience. The
same principle obtains in all that concerns the lifting and the moving of
Sick people take great comfort in the use of fresh linen and fresh
pillows. Two sets should be used, letting one be aired while the other is
in use. In making changes the fresh linen should be thoroughly aired and
warmed and everything in readiness before the patient is disturbed.
386. Rules for Sick-room. Do not deceive sick people. Tell what is
proper or safe to be told, promptly and plainly. If a physician is
employed, carry out his orders to the very letter, as long as he visits
you. Make on a slip of paper a note of his directions. Make a brief record
of exactly what to do, the precise time of giving medicines, etc. This
should always be done in serious cases, and by night watchers. Then there
is no guesswork. You have the record before you for easy reference. All
such things are valuable helps to the doctor.
Whatever must be said in the sick-room, say it openly and aloud. How often
a sudden turn in bed, or a quick glance of inquiry, shows that whispering
is doing harm! If the patient is in his right mind, answer his questions
plainly and squarely. It may not be best to tell all the truth, but
nothing is gained in trying to avoid a straightforward reply.
Noises that are liable to disturb the patient, in other parts of the house
than the sick-room, should be avoided. Sounds of a startling character,
especially those not easily explained, as the rattling or slamming of
distant blinds and doors, are always irritating to the sick.
Always attract the attention of a patient before addressing him, otherwise
he may be startled and a nervous spell be induced. The same hint applies
equally to leaning or sitting upon the sick-bed, or running against
furniture in moving about the sick-room.
387. Rest of Mind and Body. The great importance of rest for the sick
is not so generally recognized as its value warrants. If it is worry and
not work that breaks down the mental and physical health of the well, how
much more important is it that the minds and bodies of the sick should be
kept at rest, free from worry and excitement! Hence the skilled nurse does
her best to aid in restoring the sick to a condition of health by securing
for her patient complete rest both of mind and body. To this end, she
skillfully removes all minor causes of alarm, irritation, or worry. There
are numberless ways in which this may be done of which space does not
allow even mention. Details apparently trifling, as noiseless shoes,
quietness, wearing garments that do not rustle, use of small pillows of
different sizes, and countless other small things that make up the
refinement of modern nursing, play an important part in building up the
impaired tissues of the sick.
388. Care of Infectious and Contagious Diseases. There are certain
diseases which are known to be infectious and can be communicated from one
person to another, either by direct contact, through the medium of the
atmosphere, or otherwise.
Of the more prevalent infectious and contagious diseases are
_scarlet fever, diphtheria, erysipelas, measles_, and _typhoid fever_.
Considerations of health demand that a person suffering from any one of
these diseases should be thoroughly isolated from all other members of the
family. All that has been stated in regard to general nursing in previous
sections of this chapter, applies, of course, to nursing infectious and
contagious diseases. In addition to these certain special directions must
be always kept in mind.
Upon the nurse, or the person having the immediate charge of the patient,
rests the responsibility of preventing the spread of infectious diseases.
The importance must be fully understood of carrying out in every detail
the measures calculated to check the spread or compass the destruction of
the germs of disease.
389. Hints on Nursing Infectious and Contagious Diseases. Strip the
room of superfluous rugs, carpets, furniture, etc. Isolate two rooms, if
possible, and have these, if convenient, at the top of the house. Tack
sheets, wet in some proper disinfectant, to the outer frame of the
sick-room door. Boil these sheets every third day. In case of diseases to
which young folks are very susceptible, send the children away, if
possible, to other houses where there are no children.
Most scrupulous care should be taken in regard to cleanliness and neatness
in every detail. Old pieces of linen, cheese-cloth, paper napkins, should
be used wherever convenient or necessary and then at once burnt. All
soiled clothing that cannot well be burnt should be put to soak at once in
disinfectants, and afterward boiled apart from the family wash. Dishes and
all utensils should be kept scrupulously clean by frequent boiling. For
the bed and person old and worn articles of clothing that can be destroyed
should be worn so far as possible.
During convalescence, or when ready to leave isolation, the patient should
be thoroughly bathed in water properly disinfected, the hair and nails
especially being carefully treated.
Many details of the after treatment depend upon the special disease, as
the rubbing of the body with carbolized vaseline after scarlet fever, the
care of the eyes after measles, and other particulars of which space does
not admit mention here.
Poisons and Their Antidotes.
390. Poisons. A poison is a substance which, if taken into the system
in sufficient amounts, will cause serious trouble or death. For
convenience poisons may be divided into two classes, irritants and
The effects of irritant poisons are evident immediately after being
taken. They burn and corrode the skin or membrane or other parts with
which they come in contact. There are burning pains in the mouth, throat,
stomach, and abdomen, with nausea and vomiting. A certain amount of
faintness and shock is also present.
With narcotic poisoning, the symptoms come on more slowly. After a
time there is drowsiness, which gradually increases until there is a
profound sleep or stupor, from which the patient can be aroused only with
great difficulty. There are some substances which possess both the
irritant and narcotic properties and in which the symptoms are of a mixed
391. Treatment of Poisoning. An antidote is a substance which will
either combine with a poison to render it harmless, or which will have a
directly opposite effect upon the body, thus neutralizing the effect of
the poison. Hence in treatment of poisoning the first thing to do, if you
know the special poison, is to give its antidote at once.
If the poison is unknown, and there is any delay in obtaining the
antidote, the first thing to do is to remove the poison from the stomach.
Therefore cause vomiting as quickly as possible. This may be done by an
emetic given as follows: Stir a tablespoonful of mustard or of common
salt in a glass of warm water and make the patient swallow the whole. It
will usually be vomited in a few moments. If mustard or salt is not at
hand, compel the patient to drink lukewarm water very freely until
Vomiting may be hastened by thrusting the forefinger down the throat. Two
teaspoonfuls of the syrup of ipecac, or a heaping teaspoonful of powdered
ipecac taken in a cup of warm water, make an efficient emetic, especially
if followed with large amounts of warm water.
It is to be remembered that in some poisons, as certain acids and
alkalies, no emetic should be given. Again, for certain poisons (except in
case of arsenic) causing local irritation, but which also affect the
system at large, no emetic should be given.
392. Reference Table of Common Poisons; Prominent Symptoms; Antidotes and
Treatment. The common poisons with their leading symptoms, treatment,
and antidotes, may be conveniently arranged for easy reference in the form
of a table.
It is to be remembered, of course, that a complete mastery of the table of
poisons, as set forth on the two following pages, is really a physician's
business. At the same time, no one of fair education should neglect to
learn a few of the essential things to do in accidental or intentional
A Table of the More Common Poisons,
With their prominent symptoms, antidotes, and treatment.
Poison Prominent Symptoms Antidotes and Treatment
Muriatic, Burning sensation in _No emetic_ Saleratus;
Nitric, mouth, throat, and chalk; soap; plaster from
Sulphuric (vitriol), stomach; blisters the wall; lime; magnesia;
Oxalic. about mouth; vomiting; baking soda (3 or 4
great weakness teaspoonfuls in a glass of
Caustic potash and Burning sensation in _No emetic_ Olive oil
soda, the parts; severe pain freely; lemon juice, vinegar;
Ammonia, in stomach; vomiting; melted butter and vaseline;
Lye, difficulty in thick cream.
Pearlash, swallowing; cold skin;
Saltpeter. weak pulse.
Paris green, Intense pains in Vomit patient repeatedly,
Rough on rats, stomach and bowels; give hydrated oxide of iron
White arsenic, thirst; vomiting, with magnesia, usually kept
Fowler's solution, perhaps with blood; by druggists for emergencies;
Scheele's green. cold and clammy skin. follow with strong solution
of common salt and water.
_Other Metallic Poisons_:
Blue vitriol, Symptoms in general, Emetic with lead; none with
Copperas, same as in arsenical copper and iron; white of
Green vitriol, poisoning. With lead eggs in abundance with
Sugar of lead, and mercury there may copper; with iron and lead
Corrosive be a metallic taste in give epsom salts freely;
sublimate, the mouth. afterwards, oils, flour, and
Bedbug poison. water. _No emetic with
mercury;_ raw eggs;
milk, or flour, and water.
Matches, rat Pain in the stomach; _Cause vomiting_.
poisons,etc. vomiting; purging; Strong soapsuds;
general collapse. magnesia in water.
Never give oils.
Morphine, Sleepiness; dullness; _Cause vomiting_. Keep
Laudanum, stupor; "pin-hole" patient awake by any means,
Paregoric, pupils; slow especially by vigorous
Dover's powder, breathing; profuse walking; give strong coffee
Soothing syrups, sweat. freely; dash cold water on
Cholera and diarrhœa face and chest.
Creasote. Severe pain in abdomen; _No emetic._ Milk or
odor of carbolic acid, flour and water; white of
mucous membrane in eggs.
around mouth white and
benumbed; cold and
Wolfsbane Numbness everywhere, _Vomit patient freely._
Monkshood great weakness; cold Stimulating drinks.
Deadly Nightshade Eyes bright, with pupil _Vomit patient freely._
Atropia enlarged; dry mouth and
_Various Vegetable Poisons_
Wild parsley, Stupor, nausea, great _Cause brisk vomiting_.
Indian tobacco, weakness and other Stimulating drinks.
Toadstools, symptoms according to
Tobacco plant, the poison.
Berries of the mountain ash,
Bitter sweet etc.
393. Practical Points about Poisons. Poisons should never be kept in
the same place with medicines or other preparations used in the household.
They should always be put in some secure place under lock and key. Never
use internally or externally any part of the contents of any package or
bottle unless its exact nature is known. If there is the least doubt
about the substance, do not assume the least risk, but destroy it at
once. Many times the unknown contents of some bottle or package has
been carelessly taken and found to be poison.
Careless and stupid people often take, by mistake, with serious, and often
fatal, results, poisonous doses of carbolic acid, bed-bug poison,
horse-liniment, oxalic acid, and other poisons. A safe rule is to keep all
bottles and boxes containing poisonous substances securely bottled or
packed, and carefully labeled with the word POISON plainly written in
large letters across the label. Fasten the cork of a bottle containing
poison to the bottle itself with copper or iron wire twisted into a knot
at the top. This is an effective means of preventing any mistakes,
especially in the night.
This subject of poisons assumes nowadays great importance, as it is a
common custom to keep about stables, workshops, bathrooms, and living
rooms generally a more or less formidable array of germicides,
disinfectants, horse-liniments, insect-poisons, and other preparations of
a similar character. For the most part they contain poisonous
394. Nature Of Bacteria. The word bacteria is the name applied to
very low forms of plant life of microscopic size. Thus, if hay be soaked
in water for some time, and a few drops of the liquid are examined under a
high power of the microscope, the water is found to be swarming with
various forms of living vegetable organisms, or bacteria. These
microscopic plants belong to the great fungus division, and consist of
many varieties, which may be roughly divided into groups, according as
they are spherical, rod-like, spiral, or otherwise in shape.
Each plant consists of a mass of protoplasm surrounded by an
ill-defined cell wall. The bacteria vary cably in size. Some of the
rod-shaped varieties are from 1/12,000 to 1/8,000 of an inch in length, and
average about 1/50,000 of an inch in diameter. It has been calculated that
a space of one cubic millimeter would contain 250,000,000 of these minute
organisms, and that they would not weigh more than a milligram.
[Illustration: Fig. 168.--Examples of Micro-Organisms called Bacteria.
(Drawn from photographs.)
A, spheroidal bacteria (called _cocci_) in pairs;
B, same kind of bacteria in chains;
C, bacteria found in pus (grouped in masses like a bunch of grapes).
[Bacteria in A, B, and C magnified about 1000 diameters].
D, bacteria found in pus (tendency to grow in the form of chains).
[Magnified about 500 diameters.]
Bacteria are propagated in a very simple manner. The parent cell divides
into two; these two into two others, and so on. The rapidity with which
these organisms multiply under favorable conditions, makes them, in some
cases, most dangerous enemies. It has been calculated that if all of the
organisms survived, one bacterium would lead to the production of several
billions of others in twenty-four hours.
395. The Struggle of Bacteria for Existence. Like all kinds of living
things, many species of bacteria are destroyed if exposed to boiling water
or steam, but seem able to endure prolonged cold, far below the
freezing-point. Thus ice from ponds and rivers may contain numerous germs
which resume their activity when the ice is melted. Typhoid fever germs
have been known to take an active and vigorous growth after they have been
kept for weeks exposed in ice to a temperature below zero.
The bacteria of consumption (bacillus tuberculosis) may retain their
vitality for months, and then the dried expectoration of the invalids may
become a source of danger to those who inhale air laden with such
impurities (sec. 220 and Fig. 94).
Like other living organisms, bacteria need warmth, moisture, and some
chemical compound which answers for food, in order to maintain the
phenomena of life. Some species grow only in contact with air, others need
no more oxygen than they can obtain in the fluid or semi-fluid which they
396. Importance of Bacteria in Nature. We might well ask why the
myriads of bacteria do not devastate the earth with their marvelous
rapidity of propagation. So indeed they might, were it not for the winds,
rains, melting snow and ice which scatter them far and wide, and destroy
Again, as in countless other species of living organisms, bacteria are
subject to the relentless law which allows only the fittest to survive.
The bacteria of higher and more complex types devour those of a lower
type. Myriads perish in the digestive tract of man and other animals. The
excreta of some species of bacteria act as poison to destroy other
It is true from the strictest scientific point of view that all living
things literally return to the dust whence they came. While living they
borrow a few elementary substances and arrange them in new combinations,
by aid of the energy given them by the sun, and after a time die and leave
behind all they had borrowed both of energy and matter.
Countless myriads of bacteria are silently at work changing dead animal
and vegetable matter into useful substances. In brief, bacteria prepare
food for all the rest of the world. Were they all destroyed, life upon
the earth would be impossible, for the elements necessary to maintain it
would be embalmed in the bodies of the dead.
397. Action of Bacteria. In certain well-known processes bacteria
have the power of bringing about decomposition of various kinds. Thus a
highly organized fungus, like the yeast plant, growing in the presence of
sugar, has the power of breaking down this complex body into simpler ones,
_viz._, alcohol and carbon dioxid.
In the same way, various forms of bacteria have the power of breaking down
complex bodies in their immediate neighborhood, the products depending
upon the substance, the kind of bacteria, and the conditions under which
they act. Thus the _bacteria lactis_ act upon the milk sugar present in
milk, and convert it into lactic acid, thus bringing about the souring of
[Illustration: Fig. 169.--Examples of Pathogenic Bacteria. (Drawn from
A, spiral form of bacteria found in cholera (Magnified about 1000
B, rod-shaped bacteria (called _bacilli_) from a culture obtained
in _anthrax_ or malignant fustule of the face. Diseased hides
carry this micro-organism, and thus may occasion disease among those
who handle hides and wool. (Magnified about 1000 diameters)
Now, while most species of bacteria are harmless, some are the cause of
sickness and death when they gain admittance to the body under certain
conditions. These disease-producing bacteria (known as _pathogenic_), when
established in the blood and tissues of the body, bring about important
chemical changes, depending upon the species of bacteria, and also produce
a particular form of disease. The production of certain diseases by the
agency of bacteria has now been proved beyond all doubt. In yellow fever,
erysipelas, diphtheria, typhoid fever, consumption and other diseases, the
connection has been definitely established.
The evil results these germs of disease produce vary greatly in kind and
severity. Thus the bacteria of Asiatic cholera and diphtheria may destroy
life in a few hours, while those of consumption may take years to produce
a fatal result. Again, the bacteria may attack some particular organ, or
group of organs, and produce mostly local symptoms. Thus in a boil there
is painful swelling due to the local effect of the bacteria, with slight
398. The Battle against Bacteria. When we reflect upon the terrible
ravages made by infectious diseases, and all their attendant evils for
these many years, we can the better appreciate the work done of late years
by tireless scientists in their efforts to modify the activity of
disease-producing bacteria. It is now possible to cultivate certain
pathogenic bacteria, and by modifying the conditions under which they are
grown, to destroy their violence.
In brief, science has taught us, within certain limitations, how to
change the virulent germs of a few diseases into harmless microbes.
399. Alcoholic Fermentation and Bacteria. Men of the lowest, as well
as of the highest, type of civilization have always known that when the
sugary juice of any fruit is left to itself for a time, at a moderately
warm temperature, a change takes place under certain conditions, and the
result is a liquid which, when drank, produces a pronounced effect upon
the body. In brief, man has long known how to make for himself alcoholic
beverages, by means of which he may become intoxicated with their
Whether it is a degraded South Sea Islander making a crude intoxicant from
a sugary plant, a Japanese preparing his favorite alcoholic beverage from
the fermentation of rice by means of a fungus plant grown for the purpose,
a farmer of this country making cider from fermenting apple juice, or a
French expert manufacturing costly champagne by a complicated process,
the outcome and the intent are one and the same. The essential thing is
to produce an alcoholic beverage which will have a marked physiological
effect. This effect is poisonous, and is due solely to the
alcoholic ingredient, without which man would have little or no use
for the otherwise harmless liquid.
While the practical process of making some form of alcoholic beverage has
been understood for these many centuries, the real reason of this
remarkable change in a wholesome fruit juice was not known until revealed
by recent progress in chemistry, and by the use of the microscope. We know
now that the change is due to fermentation, brought about from the
influence, and by the action, of bacteria (sec. 125).
In other words, fermentation is the result of the growth of low form of
vegetable life known as an organised ferment. The ferment, whether it
be the commonly used brewer's yeast, or any other species of alcoholic
ferment, has the power to decompose or break down a large part of the
sugar present in the liquid into alcohol, which remains as a poison,
and _carbon dioxid_, which escapes more or less completely.
Thus man, ever prone to do evil, was once obliged, in his ignorance, to
make his alcoholic drinks in the crudest manner; but now he has forced
into his service the latest discoveries in science, more especially in
bacteriology, that he may manufacture more scientifically and more
economically alcoholic beverages of all sorts and kinds, and distribute
them broadcast all over God's earth for the physical and moral ruin of the
400. Disinfectants, Antiseptics, and Deodorants. The word
disinfectant is synonymous with the term _bactericide_ or _germicide_. A
disinfectant is a substance which destroys infectious material. An
antiseptic is an agent which may hinder the growth, but does not
destroy the vitality, of bacteria. A deodorant is not necessarily a
disinfectant, or even an antiseptic, but refers to a substance that
destroys or masks offensive odors.
401. Air and Water as Disinfectants. Nature has provided for our
protection two most efficient means of disinfection,--pure air (sec.
218) and pure water (sec. 119). The air of crowded rooms contains
large quantities of bacteria, whereas in pure air there are comparatively
few, especially after rain, which carries them to the earth. Living
micro-organisms have never been detected in breezes coming from the sea,
but in those blowing out from the shore large numbers may be found.
In water tainted with organic matter putrefactive bacteria will flourish,
whereas pure water is fatal to their existence. Surface water, because it
comes from that part of the soil where bacteria are most active, and where
there is most organic matter, generally contains great quantities of these
organisms. In the deeper strata of the soil there is practically no
decomposition of organic matter going on, hence, water taken from deep
sources is comparatively free from bacteria. For this reason, deep well
water is greatly to be preferred for drinking purposes to that from
402. Disinfectants. It is evident that air and water are not always
sufficient to secure disinfection, and this must be accomplished by other
means. The destruction of infected material by fire is, of course, a sure
but costly means of disinfection. Dry heat, steam, and boiling water are
valuable disinfectants and do not injure most fabrics. These agents are
generally used in combination with various chemical disinfectants.
Certain chemical agents that are capable of destroying micro-organisms
and their spores have come, of late years, into general use. A form of
mercury, called _corrosive sublimate_, is a most efficacious and powerful
germicide, but is exceedingly poisonous and can be bought only under
restrictions. _Carbolic acid, chloride of lime, permanganate of
potash_, and various other preparations made from zinc, iron, and
petroleum, are the chemical disinfectants most commonly and successfully
used at the present time. There are also numerous varieties of commercial
disinfectants now in popular use, such as Platt's chlorides,
bromo-chloral, sanitas, etc., which have proved efficient germicides.
Instructions for the Management of Contagious Diseases.
The following instructions for the management of contagious diseases were
prepared for the National Board of Health by an able corps of scientists
and experienced physicians.
403. Instructions for Disinfection. Disinfection is the destruction
of the poisons of infectious and contagious diseases. Deodorizers, or
substances which destroy smells, are not necessarily disinfectants, and
disinfectants do not necessarily have an odor. Disinfection cannot
compensate for want of cleanliness nor of ventilation.
404. Disinfectants to be Employed. 1. Roll sulphur (brimstone); for
2. Sulphate of iron (copperas) dissolved in water in the proportion of one
and a half pounds to the gallon; for soil, sewers, etc.
[NOTE. A most useful little manual to consult in connection with this
chapter is the _Hand-Book of Sanitary Information_, written by Roger
S. Tracy, Sanitary Inspector of the New York City Health Department.
Price, 50 cents.]
3. Sulphate of zinc and common salt, dissolved together in water in the
proportion of four ounces sulphate and two ounces salt to the gallon; for
clothing, bed-linen, etc.
405. How to Use Disinfectants. 1. _In the sick-room._ The most
available agents are fresh air and cleanliness. The clothing,
towels, bed-linen, etc., should, on removal from the patient, and before
they are taken from the room, be placed in a pail or tub of the zinc
solution, boiling-hot, if possible.
All discharges should either be received in vessels containing copperas
solution, or, when this is impracticable, should be immediately covered
with copperas solution. All vessels used about the patient should be
cleansed with the same solution.
Unnecessary furniture, especially that which is stuffed, carpets, and
hangings, should, when possible, be removed from the room at the outset;
otherwise they should remain for subsequent fumigation and treatment.
2. _Fumigation_. Fumigation with sulphur is the only practicable method
for disinfecting the house. For this purpose, the rooms to be disinfected
must be vacated. Heavy clothing, blankets, bedding, and other articles
which cannot be treated with zinc solution, should be opened and exposed
during fumigation, as directed below. Close the rooms as tightly as
possible, place the sulphur in iron pans supported upon bricks placed in
washtubs containing a little water, set it on fire by hot coals or with
the aid of a spoonful of alcohol, and allow the room to remain closed for
twenty-four hours. For a room about ten feet square, at least two pounds
of sulphur should be used; for larger rooms, proportionally increased
3. _Premises_. Cellars, yards, stables, gutters, privies, cesspools,
water-closets, drains, sewers, etc., should be frequently and liberally
treated with copperas solution. The copperas solution is easily prepared
by hanging a basket containing about sixty pounds of copperas in a barrel
4. _Body and bed clothing, etc_. It is best to burn all articles which
have been in contact with persons sick with contagious or infectious
diseases. Articles too valuable to be destroyed should be treated as
_(a)_ Cotton, linen, flannels, blankets, etc., should be treated with the
boiling-hot zinc solution; introduce piece by piece, secure thorough
wetting, and boil for at least half an hour.
_(b)_ Heavy woolen clothing, silks, furs, stuffed bed-covers, beds, and
other articles which cannot be treated with the zinc solution, should be
hung in the room during fumigation, their surfaces thoroughly exposed and
pockets turned inside out. Afterward they should be hung in the open air,
beaten, and shaken. Pillows, beds, stuffed mattresses, upholstered
furniture, etc., should be cut open, the contents spread out and
thoroughly fumigated. Carpets are best fumigated on the floor, but should
afterward be removed to the open air and thoroughly beaten.
Books for Collateral Study. Among the many works which may be
consulted with profit, the following are recommended as among those most
useful: Parkes _Elements of Health_; Canfield's _Hygiene of the
Sick-Room;_ Coplin & Bevan's _Practical Hygiene;_ Lincoln's _School
Hygiene_; Edward Smith's _Health_; McSherrys _Health; American Health
Primers_ (12 little volumes, edited by Dr. Keen of Philadelphia);
Reynold's _Primer of Health_; Corfield's _Health_; Appleton's _Health
Primers;_ Clara S. Weeks' _Nursing_; Church's _Food_; Yeo's _Food in Health
and Disease;_ Hampton's _Nursing, its Principles and Practice_; Price's
_Nurses and Nursing;_ Cullinworth's _Manual of Nursing_; Wise's _Text-Book
of Nursing_ (2 vols.); and Humphrey's _Manual of Nursing_.
Experimental Work in Physiology.
406. The Limitations of Experimental Work in Physiology in Schools.
Unlike other branches of science taught in the schools from the
experimental point of view, the study of physiology has its limitations.
The scope and range of such experiments is necessarily extremely limited
compared with what may be done with the costly and elaborate apparatus of
the medical laboratory. Again, the foundation of physiology rests upon
systematic and painstaking dissection of the dead human body and the lower
animals, which mode of study very properly is not permitted in ordinary
school work. Experiments upon the living human body and the lower animals,
now so generally depended upon in our medical and more advanced scientific
schools, for obvious reasons can be performed only in a crude and quite
superficial manner in secondary schools.
Hence in the study of physiology in schools many things must be taken for
granted. The observation and experience of medical men, and the
experiments of the physiologist in his laboratory must be depended upon
for data which cannot be well obtained at first hand by young students.
407. Value of Experiments in Physiology in Secondary Schools. While
circumstances and regard for certain proprieties of social life forbid the
use of a range of experiments, in anatomy and physiology, such as are
permitted in other branches of science in secondary schools, it by no
means follows that we are shut out altogether from this most important and
interesting part of the study. However simple and crude the apparatus, the
skillful and enthusiastic teacher has at his command a wide series of
materials which can be profitably utilized for experimental instruction.
As every experienced teacher knows, pupils gain a far better knowledge,
and keep up a livelier interest in any branch of science, if they see with
their own eyes and do with their own hands that which serves to illuminate
and illustrate the subject-matter.
[NOTE. For additional suggestions and practical helps on the subject
of experimental work in physiology the reader is referred to
Blaisdell's _How to Teach Physiology_, a handbook for teachers. A copy
of this pamphlet will be sent postpaid to any address by the
publishers of this book on receipt of ten cents.]
The experimental method of instruction rivets the attention and arouses
and keeps alive the interest of the young student; in fact, it is the
only true method of cultivating a scientific habit of study. The
subject-matter as set forth on the printed pages of this book should be
mastered, of course, but at the same time the topics discussed should be
illuminated and made more interesting and practical by a well-arranged
series of experiments, a goodly show of specimens, and a certain amount of
408. The Question of Apparatus. The author well understands from
personal experience the many practical difficulties in the way of
providing a suitable amount of apparatus for classroom use. If there are
ample funds for this purpose, there need be no excuse or delay in
providing all that is necessary from dealers in apparatus in the larger
towns, from the drug store, markets, and elsewhere. In schools where both
the funds and the time for such purposes are limited, the zeal and
ingenuity of teachers and students are often put to a severe test.
Fortunately a very little money and a great deal of ingenuity and patience
will do apparent wonders towards providing a working supply of apparatus.
It will be noticed that many of the experiments in the preceding chapters
of this book can be performed with very simple, and often a crude and
home-made sort of apparatus. This plan has been rigidly followed by the
author, first, because he fully realizes the limitations and restrictions
of the subject; and secondly, because he wishes to emphasize the fact that
expensive and complicated apparatus is by no means necessary to illustrate
the great principles of anatomy and physiology.
409. Use of the Microscope. To do thorough and satisfactory work in
physiology in our higher schools a compound microscope is almost
indispensable. Inasmuch as many of our best secondary schools are equipped
with one or more microscopes for use in other studies, notably botany, it
is much less difficult than it was a few years ago to obtain this
important help for the classes in physiology.
[Illustration: Fig. 170.--A Compound Microscope]
For elementary class work a moderate-priced, but well-made and strong,
instrument should be provided. If the school does not own a microscope,
the loan of an instrument should be obtained for at least a few weeks from
some person in the neighborhood.
The appearance of the various structures and tissues of the human body as
revealed by the microscope possesses a curious fascination for every
observer, especially for young people. No one ever forgets the first look
at a drop of blood, or the circulation of blood in a frog's foot as shown
by the microscope.
[NOTE. For detailed suggestions in regard to the manipulation and use
of the microscope the student is referred to any of the standard works
on the subject. The catalogues of scientific-instrument makers of our
larger cities generally furnish a list of the requisite materials or
handbooks which describe the use of the various microscopes of
The author is indebted to Bergen's _Elements of Botany_ for the
following information concerning the different firms which deal in
microscopes. "Several of the German makers furnish excellent
instruments for use in such a course as that here outlined. The author
is most familar with the Leitz microscopes, which are furnished by Wm.
Krafft, 411 West 59th St., New York city, or by the Franklin
Educational Co., 15 and 17 Harcourt St., Boston. The Leitz Stand, No.
IV., can be furnished duty free (for schools only), with objectives 1,
3, and 5, eye-pieces I. and III., for $24.50. If several instruments
are being provided, it would be well to have part of them equipped
with objectives 3 and 7, and eye-pieces I. and III.
"The American manufacturers, Bausch & Lomb Optical Company, Rochester,
N.Y., and No. 130 Fulton St., New York city, have this year produced a
microscope of the Continental type which is especially designed to
meet the requirements of the secondary schools for an instrument with
rack and pinion coarse adjustment and serviceable fine adjustment, at
a low price. They furnish this new stand, 'AAB,' to schools and
teachers at 'duty-free' rates, the prices being for the stand with two
eye-pieces (any desired power), ⅔-inch and ¼-inch objectives,
$25.60, or with 2-inch, ⅔-inch, and ¼-inch objectives, and two
eye-pieces, $29.20. Stand 'A,' the same stand as the 'AAB,' without
joint and with sliding tube coarse adjustment (as in the Leitz Stand
IV.), and with three eye-pieces and ⅔-inch and ¼-inch objectives,
is furnished for $20.40. Stand 'A,' with two eye-pieces, ⅔-inch and
⅙-inch objectives, $20.40."]
410. The Use of the Skeleton and Manikin. The study of the bones by
the help of a skeleton is almost a necessity. To this intent, schools of a
higher grade should be provided both with a skeleton and a
manikin. If the former is not owned by the school, oftentimes a loan
of one can be secured of some medical man in the vicinity. Separate bones
will also prove useful. In fact, there is no other way to study properly
the structure and use of the bones and joints than by the bones
themselves. A good manikin is also equally serviceable, although not so
commonly provided for schools on account of its cost.
411. The Question of Vivisection and Dissection. There should be no
question at all concerning vivisection. _In no shape or form should
it be allowed in any grade of our schools._ Nor is there any need of much
dissection in the grammar-school grades. A few simple dissections to
be performed with fresh beef-joints, tendons of turkey legs, and so on,
will never engender cruel or brutal feelings toward living things. In the
lower grades a discreet teacher will rarely advise his pupils to dissect a
dead cat, dog, frog, or any other animal. Instead of actual dissection,
the pupils should examine specimens or certain parts previously dissected
by the teacher,--as the muscles and tendons of a sheep, the heart of an
ox, the eye of a codfish, and so on. Even under these restrictions the
teacher should not use the knife or scissors before the class to open up
any part of the specimen. In brief, avoid everything that can possibly
arouse any cruel or brutal feeling on the part of young students.
In the higher schools, in normal and other training schools, different
conditions prevail. Never allow vivisection in any form whatever, either
in school or at home. Under the most exact restrictions students in these
schools may be taught to make a few simple dissections.
Most teachers will find, however, even in schools of a higher grade, that
the whole subject is fraught with many difficulties. It will not require
much oftentimes to provoke in a community a deal of unjust criticism. A
teacher's good sense and discretion are often put to a severe test.
To the somewhat extended list of experiments as described in the preceding
chapters a few more are herewith presented which may be used as
opportunity allows to supplement those already given.
Experiment 193. _To examine white fibrous tissue._ Snip off a very
minute portion from the muscle of a rabbit, or any small animal recently
dead. Tease the specimen with needles, mount in salt solution and
examine under a high power. Note the course and characters of the
Experiment 194. _To examine elastic tissue._ Tease out a small
piece of ligament from a rabbit's leg in salt solution; mount in the
same, and examine as before. Note the curled elastic fibers.
Experiment 195. _To examine areolar tissue._ Gently tease apart
some muscular fibers, noting that they are attached to each other by
connective tissue. Remove a little of this tissue to a slide and examine
as before. Examine the matrix with curled elastic fiber mixed with
straight white fibers.
Experiment 196. _To examine adipose tissue._ Take a bit of fat from
the mesentery of a rabbit. Tease the specimen in salt solution and mount
in the same. Note the fat cells lying in a vascular meshwork.
Experiment 197. _To examine connective tissues._ Take a very small
portion from one of the tendons of a rabbit, or any animal recently
dead; place upon a glass slide with a drop of salt solution; tease it
apart with needles, cover with thin glass and examine with microscope.
The fine wavy filaments will be seen. Allow a drop of dilute acetic acid
to run under the cover glass; the filaments will swell and become
Experiment 198. Tease out a small piece of ligament from the
rabbit's leg in salt solution; mount in the same, and examine under a
high power. Note the curled elastic fibers.
Experiment 199. _A crude experiment to represent the way in which a
person's neck is broken._ Bring the ends of the left thumb and the left
second finger together in the form of a ring. Place a piece of a wooden
toothpick across it from the middle of the finger to the middle of the
thumb. Put the right forefinger of the other hand up through the front
part to represent the odontoid process of the axis, and place some
absorbent cotton through the other part to represent the spinal cord.
Push backwards with the forefinger with just enough force to break the
toothpick and drive its fragments on to the cotton.
Experiment 200. _To illustrate how the pulse-wave is transmitted
along an artery._ Use the same apparatus as in Experiment 106, p. 201.
Take several thin, narrow strips of pine wood. Make little flags by
fastening a small piece of tissue paper on one end of a wooden
toothpick. Wedge the other end of the toothpick into one end of the
strips of pine wood. Use these strips like levers by placing them across
the long rubber tube at different points. Let each lever compress the
tube a little by weighting one end of it with a blackboard eraser or
book of convenient size.
As the pulse-wave passes along under the levers they will be
successively raised, causing a slight movement of the tissue-paper
Experiment 201. _The dissection of a sheep's heart._ Get a sheep's
heart with the lungs attached, as the position of the heart will be
better understood. Let the lungs be laid upon a dish so that the heart
is uppermost, with its apex turned toward the observer.
The line of fat which extends from the upper and left side of the heart
downwards and across towards the right side, indicates the division
between the right and left ventricles.
Examine the large vessels, and, by reference to the text and
illustrations, make quite certain which are the _aorta_, the _pulmonary
artery_, the _superior_ and _inferior venæ cavæ_, and the _pulmonary
Tie variously colored yarns to the vessels, so that they may be
distinguished when separated from the surrounding parts.
Having separated the heart from the lungs, cut out a portion of the wall
of the _right ventricle_ towards its lower part, so as to lay the cavity
open. Gradually enlarge the opening until the _chordæ tendineæ_ and the
flaps of the _tricuspid valve_ are seen. Continue to lay open the
ventricle towards the pulmonary artery until the _semilunar valves_ come
The pulmonary artery may now be opened from above so as to display the
upper surfaces of the semilunar valves. Remove part of the wall of the
right auricle, and examine the right auriculo-ventricular opening.
The heart may now be turned over, and the _left ventricle_ laid open in
a similar manner. Notice that the mitral valve has only two flaps. The
form of the valves is better seen if they are placed under water, and
allowed to float out. Observe that the walls of the _left_ ventricle are
much thicker than those of the _right_.
Open the left auricle, and notice the entrance of the _pulmonary veins_,
and the passage into the ventricle.
The ventricular cavity should now be opened up as far as the aorta, and
the semilunar valves examined. Cut open the aorta, and notice the form
of the _semilunar valves_.
Experiment 202. _To show the circulation in a frog's foot_ (see
Fig. 78, p. 192). In order to see the blood circulating in the membrane
of a frog's foot it is necessary to firmly hold the frog. For this
purpose obtain a piece of soft wood, about six inches long and three
wide, and half an inch thick. At about two inches from one end of this,
cut a hole three-quarters of an inch in diameter and cover it with a
piece of glass, which should be let into the wood, so as to be level
with the surface. Then tie up the frog in a wet cloth, leaving one of
the hind legs outside. Next, fasten a piece of cotton to each of the two
longest toes, but not too tightly, or the circulation will be stopped
and you may hurt the frog.
Tie the frog upon the board in such a way that the foot will just come
over the glass in the aperture. Pull carefully the pieces of cotton tied
to the toes, so as to spread out the membrane between them over the
glass. Fasten the threads by drawing them into notches cut in the sides
of the board. The board should now be fixed by elastic bands, or by any
other convenient means, upon the stage of the microscope, so as to bring
the membrane of the foot under the object glass.
The flow of blood thus shown is indeed a wonderful sight, and never to
be forgotten. The membrane should be occasionally moistened with water.
Care should be taken not to occasion any pain to the frog.
Experiment 203. _To illustrate the mechanics of respiration_
(see Experiment 122, p. 234). "In a large lamp-chimney, the top of which
is closed by a tightly fitting perforated cork (A), is arranged a pair
of rubber bags (C) which are attached to a Y connecting tube (B), to be
had of any dealer in chemical apparatus or which can be made by a
teacher having a bunsen burner and a little practice in the manipulation
of glass (Fig. 171). From the center of the cork is attached a rubber
band by means of a staple driven through the cork, the other end of
which (D) is attached to the center of a disk of rubber (E) such as
dentists use. This disk is held to the edge of the chimney by a wide
elastic band (F). There is a string (G) also attached to the center of
the rubber disk by means of which the diaphragm may be lowered.
[Illustration: Fig. 171.]
Such is a description of the essentials of the model. The difficulties
encountered in its construction are few and easily overcome. In the
first place, the cork must be air-tight, and it is best made so by
pouring a little melted paraffin over it, care being taken not to close
the tube. The rubber bags were taken from toy balloon-whistles.
In the construction of the diaphragm, it is to be remembered that it
also must be air-tight, and in order to resemble the human diaphragm, it
must have a conical appearance when at rest. In order to avoid making
any holes in the rubber, the two attachments (one of the rubber band,
and the other of the string) were made in this wise: the rubber was
stretched over a button having an eye, then under the button was placed
a smaller ring from an old umbrella; to this ring was attached the
rubber band, and to the eye of the button was fastened the operating
string. When not in use the diaphragm should be taken off to relieve the
strain on the rubber band."
Experiment 204. _To illustrate the action of the intercostal
muscles_ (see sec. 210). The action of the intercostal muscles is not at
first easy to understand; but it will be readily comprehended by
reference to a model such as that represented in Fig. 172. This maybe
easily made by the student himself with four laths of wood, fastened
together at the corners, A, B, C, D, with pins or small screws, so as
to be movable. At the points E, F, G, H, pins are placed, to which
elastic bands may be attached (A). B D represents the vertebral column;
A C, the sternum; and A B and C D, the ribs. The elastic band F G
represents the _external_ intercostal muscles, and E H, the _internal_
[Illustration: Fig. 172.]
If now the elastic band E H be removed, the remaining band, F G, will
tend to bring the two points to which it is attached, nearer together,
and the result will be that the bars A B and C D will be drawn upwards
(B), that is, in the same direction as the ribs in the act of
_inspiration_. When the elastic band E H is allowed to exert its force,
the opposite effect will be produced (C); in this case representing the
position of the ribs in an act of _expiration_.
Experiment 205. Pin a round piece of bright red paper (large as a
dinner-plate) to a white wall, with a single pin. Fasten a long piece of
thread to it, so it can be pulled down in a moment. Gaze steadily at the
red paper. Have it removed while looking at it intently, and a greenish
spot takes its place.
Experiment 206. Lay on different parts of the skin a small, square
piece of paper with a small central hole in it. Let the person close his
eyes, while another person gently touches the uncovered piece of skin
with cotton wool, or brings near it a hot body. In each case ask the
observed person to distinguish between them. He will always succeed on
the volar side of the hand, but occasionally fail on the dorsal surface
of the hand, the extensor surface of the arm, and very frequently on the
skin of the back.
Experiment 207. _Wheatstone's fluttering hearts_. Make a drawing of
a red heart on a bright blue ground. In a dark room lighted by a candle
hold the picture below the level of the eyes and give it a gentle
to-and-fro motion. On continuing to look at the heart it will appear to
move or flutter over the blue background.
Experiment 208. At a distance of six inches from the eyes hold a
veil or thin gauze in front of some printed matter placed at a distance
of about two feet. Close one eye, and with the other we soon see either
the letters distinctly or the fine threads of the veil, but we cannot
see both equally distinct at the same time. The eye, therefore, can form
a distinct image of a near or distant object, but not of both at the
same time; hence the necessity for accommodation.
Experiment 209. Place a person in front of a bright light opposite
a window, and let him look at the light; or place one's self opposite a
well-illuminated mirror. Close one eye with the hand and observe the
diameter of the other pupil. Then suddenly remove the hand from the
closed eye: light falls upon it; at the same time the pupil of the other
Experiment 210. _To illustrate the blind spot. Marriott's
experiment_. On a white card make a cross and a large dot, either black
or colored. Hold the card vertically about ten inches from the right
eye, the left being closed. Look steadily at the cross with the right
eye, when both the cross and the circle will be seen. Gradually approach
the card toward the eye, keeping the axis of vision fixed on the cross.
At a certain distance the circle will disappear, i.e., when its image
falls on the entrance of the optic nerve. On bringing the card nearer,
the circle reappears, the cross, of course, being visible all the time
(see Experiment 180, p. 355).
Experiment 211. _To map out the field of vision_. A crude method is
to place the person with his back to a window, ask him to close one eye,
stand in front of him about two feet distant, hold up the forefingers of
both hands in front of and in the plane of your own face. Ask the person
to look steadily at your nose, and as he does so observe to what extent
the fingers can be separated horizontally, vertically, and in oblique
directions before they disappear from his field of vision.
Experiment 212. _To illustrate imperfect judgment of distance_.
Close one eye and hold the left forefinger vertically in front of the
other eye, at arm's length, and try to strike it with the right
On the first trial one will probably fall short of the mark, and fail to
touch it. Close one eye, and rapidly try to dip a pen into an inkstand,
or put a finger into the mouth of a bottle placed at a convenient
distance. In both cases one will not succeed at first.
In these cases one loses the impressions produced by the convergence of
the optic axes, which are important factors in judging of distance.
Experiment 213. Hold a pencil vertically about twelve inches from
the nose, fix it with both eyes, close the left eye, and then hold the
right index finger vertically, so as to cover the lower part of the
pencil. With a sudden move, try to strike the pencil with the finger. In
every case one misses the pencil and sweeps to the right of it.
Experiment 214. _To illustrate imperfect judgment of direction_. As
the retina is spherical, a line beyond a certain length when looked at
always shows an appreciable curvature.
Hold a straight edge just below the level of the eyes. Its upper margin
shows a slight concavity.
Surface Anatomy and Landmarks.
In all of our leading medical colleges the students are carefully and
thoroughly drilled on a study of certain persons selected as models. The
object is to master by observation and manipulation the details of what is
known as surface anatomy and landmarks. Now while detailed work of this
kind is not necessary in secondary schools, yet a limited amount of study
along these lines is deeply interesting and profitable. The habit of
looking at the living body with anatomical eyes and with eyes at our
fingers' ends, during the course in physiology, cannot be too highly
In elementary work it is only fair to state that many points of surface
anatomy and many of the landmarks cannot always be defined or located with
precision. A great deal in this direction can, however, be done in higher
schools with ingenuity, patience, and a due regard for the feelings of all
concerned. Students should be taught to examine their own bodies for this
purpose. Two friends may thus work together, each serving as a "model" to
To the following syllabus may be added such other similar exercises as
ingenuity may suggest or time permit.
I. Bony Landmarks.
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