Experiment 180. _To illustrate the duration of retinal impressions_. On

a circular white disk, about halfway between the center and

circumference, fix a small, black, oblong disk, and rapidly rotate it

by means of a rotating wheel. There appears a ring of gray on the

black, showing that the impression on the retina lasts a certain time.

Illustration: Fig. 146.—Optic Disks.

The disk A, having black and white sectors, when rotated rapidly gives

an even gray tint as in B.

Experiment 181. Mark off a round piece of cardboard into black and

white sectors as in A (Fig. 146). Attach it so as to rotate it rapidly,

as on a sewing machine. An even gray tint will be produced as in B.

Experiment 182._To illustrate imperfect visual judgments_. Make three

round black dots, A, B, C, of the same size, in the same line, and let

A and C be equidistant from B. Between A and B make several more dots

of the same size. A and B will then appear to be farther apart than B

and C.

Illustration:

For the same reason, of two squares absolutely identical in size, one

marked with alternately clear and dark cross-bands, and the other with

alternately clear and dark upright markings, the former will appear

broader and the latter higher than the other.

Experiment 183. Make on a white card two squares of equal size. Across

the one draw _horizontal_ lines at equal distances, and in the other

make similar _vertical_ lines. Hold them at some distance. The one with

horizontal lines appears higher than it really is, while the one with

vertical lines appears broader, _i.e._, both appear oblong.

Experiment 184. Look at the row of letters (S) and figures (8). To some

the upper halves of the letters and figures may appear to be of the

same size as the lower halves, to others the lower halves may appear

larger. Hold the figure upside down, and observe that there is a

considerable difference between the two, the lower halves being

considerably larger.

S S S S S S S S 8 8 8 8 8 8 8 8

Experiment 185. _To illustrate imperfect visual judgment_. The length

of a line appears to vary according to the angle and direction of

certain other lines in relation to it (Fig. 147). The length of the two

vertical lines is the same, yet B appears much longer than A.

Illustration: Fig. 147.—To show False Estimate of Size.

Experiment 186. In indirect vision the appreciation of direction is

still more imperfect. While leaning on a large table, fix a point on

the table, and then try to arrange three small pieces of colored paper

in a straight line. Invariably, the papers, being at a distance from

the fixation-point, and being seen by indirect vision, are arranged,

not in a straight line, but in the arc of a circle with a long radius.

Chapter XII.

The Throat and the Voice.

349. The Throat. The throat is a double highway, as it were, through

which the air we breathe traverses the larynx on its way to the lungs,

and through which the food we swallow reaches the œsophagus on its

passage to the stomach. It is, therefore, a very important region of

the body, being concerned in the great acts of respiration and

digestion.

The throat is enclosed and protected by various muscles and bony

structures, along which run the great blood-vessels that supply the

head, and the great nerve trunks that pass from the brain to the parts

below.

We have already described the food passages (Chapter VI.) and the air

passages (Chapter VIII.).

To get a correct idea of the throat we should look into the wide-open

mouth of some friend. Depressing the tongue we can readily see the back

wall of the pharynx, which is common to the two main avenues leading to

the lungs and the stomach. Above, we notice the air passages, which

lead to the posterior cavities of the nose. We have already described

the hard palate, the soft palate, the uvula, and the tonsils (Fig. 46).

On looking directly beyond these organs, we see the beginning of the

downward passage,—the pharynx. If now the tongue be forcibly drawn

forward, a curved ridge may be seen behind it. This is the epiglottis,

which, as we have already learned shuts down, like the lid of a box,

over the top of the larynx (secs. 137 and 203).

The throat is lined with mucous membrane covered with ciliated

epithelium, which secretes a lubricating fluid which keeps the parts

moist and pliable. An excess of this secretion forms a thick, tenacious

mass of mucus, which irritates the passages and gives rise to efforts

of hawking and coughing to get rid of it.

350. The Larynx. The larynx, the essential organ of voice, forms the

box-like top of the windpipe. It is built of variously shaped

cartilages, connected by ligaments. It is clothed on the outside with

muscles; on the inside it is lined with mucous membrane, continuous

with that of the other air passages.

Illustration: Fig. 148.—View of the Cartilages in front project and

form the lages and Ligaments of the “Adam’s apple,” plainly seen and

Larynx. (Anterior view.)

A, hyoid bone;

B, thyro-hyoid membrane;

C, thyroid cartilage;

D, erico-thyroid membrane;

E, cricoid cartilage, lateral ligaments seen on each side;

F, upper ring of the trachea.

(“Adam’s apple” is in the V-shaped groove on a line with B and C.)

The larynx has for a framework two cartilages, the thyroid and the

cricoid, one above the other. The larger of these, called the thyroid,

from a supposed resemblance to a shield, consists of two extended wings

which join in front, but are separated by a wide interval behind. The

united edges in front project and form the “Adam’s apple” plainly seen

and easily felt on most people, especially on very lean men.

Above and from the sides rise two horns connected by bands to the hyoid

bone from which the larynx is suspended. This bone is attached by

muscles and ligaments to the skull. It lies at the base of the tongue,

and can be readily felt by the finger behind the chin at the angle of

the jaw and the neck (sec. 41 and Fig. 46). From the under side of the

thyroid two horns project downwards to become jointed to the cricoid.

The thyroid thus rests upon, and is movable on, the cricoid cartilage.

The cricoid cartilage, so called from its fancied resemblance to a

signet-ring, is smaller but thicker and stronger than the thyroid, and

forms the lower and back part of the cavity of the larynx. This

cartilage is quite sensitive to pressure from the fingers, and is the

cause of the sharp pain felt when we try to swallow a large and hard

piece of food not properly chewed.

Illustration: Fig. 149.—Diagram of a Sectional of Nasal and Throat

Passages.

C, nasal cavities;

T, tongue;

L, lower jaw;

M, mouth;

U, uvula;

E, epiglottis;

G, larynx;

O, œsophagus.

On the upper edge of the cricoid cartilage are perched a pair of very

singular cartilages, pyramidal in shape, called the arytenoid, which

are of great importance in the production of the voice. These

cartilages are capped with little horn-like projections, and give

attachment at their anterior angles to the true vocal cords, and at

their posterior angles to the muscles which open and close the glottis,

or upper opening of the windpipe. When in their natural position the

arytenoid cartilages resemble somewhat the mouth of a pitcher, hence

their name.

351. The Vocal Cords. The mucous membrane which lines the various

cartilages of the larynx is thrown into several folds. Thus, one fold,

the free edge of which is formed of a band of elastic fibers, passes

horizontally outwards from each side towards the middle line, at the

level of the base of the arytenoid cartilages. These folds are called

the true vocal cords, by the movements of which the voice is produced.

Above them are other folds of mucous membrane called the false vocal

cords, which take no part in the production of the voice. The

arrangement of the true vocal cords, projecting as they do towards the

middle line, reduces to a mere chink the space between the part of the

larynx above them and the part below them. This constriction of the

larynx is called the glottis.

Illustration: Fig. 150.—View of the Cartilages and Ligaments of Larynx.

(Posterior view.)

A, epiglottis;

B, thyroid cartilage;

C, arytenoid cartilage;

D, ligament connecting lower cornu of the thyroid with the back of

the cricoid cartilage;

E, cricoid cartilage;

F, upper ring of the trachea.

352. The Mechanism of the Voice. The mechanism of the voice may be more

easily understood by a study of Fig. 150. We have here the larynx,

viewed from behind, with all the soft parts in connection with it. On

looking down, the folds forming the true vocal cords are seen enclosing

a V-shaped aperture (the glottis), the narrow part being in front.

The form of this aperture may be changed by the delicately coordinate

activities of the muscles of the larynx. For instance, the vocal cords

may 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 another.

Illustration: Fig. 151.—Longitudinal Section of the Larynx. (Showing

the vocal cords.)

A, epiglottis;

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;

K, trachea;

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 of expiration.

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.[50]

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 singing.

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 instrument.

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 insubordinate.

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 phlegm.

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 indulgences.

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.

Additional Experiments.

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 by

dentists.

“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.”[51]—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

cents.

Chapter XIII.

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 sudden illness.

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.[52]

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

it.

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

Artery.

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[53] 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

surgically clean.

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.

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.

Illustration: Fig. 158.—Showing how a Square Knot may be tied with a

Cord and a Handkerchief.

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 artery.

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 firmly lodged.

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

attendance.

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 acid.

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

Artery.

_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 a _Tourniquet_).

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

back.

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 mines.

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 minute.

Illustration: Fig. 164.—The Sylvester Method. (First

movement—inspiration.)

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 vigorous manner.

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

movement—expiration.)

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

(sec. 378).

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 purpose.

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.

Chapter XIV.

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 and draughts.

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 the sick.

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

narcotics.

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 character.

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 occurs.

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 poisoning.

A Table of the More Common Poisons,

With their prominent symptoms, antidotes, and treatment.

Poison Prominent Symptoms Antidotes and Treatment _Strong

Acids:_

Muriatic,

Nitric,

Sulphuric (vitriol),

Oxalic.

Burning sensation in mouth, throat, and stomach; blisters about mouth;

vomiting; great weakness _No emetic_ Saleratus; chalk; soap; plaster

from the wall; lime; magnesia; baking soda (3 or 4 teaspoonfuls in a

glass of water). _Alkalies_:

Caustic potash and soda,

Ammonia,

Lye,

Pearlash,

Saltpeter.

Burning sensation in the parts; severe pain in stomach; vomiting;

difficulty in swallowing; cold skin; weak pulse. _No emetic_ Olive

oil freely; lemon juice, vinegar; melted butter and vaseline; thick

cream. _Arsenic:_

Paris green,

Rough on rats,

White arsenic,

Fowler’s solution,

Scheele’s green. Intense pains in stomach and bowels; thirst; vomiting,

perhaps with blood; cold and clammy skin. Vomit patient repeatedly,

give hydrated oxide of iron with magnesia, usually kept by druggists

for emergencies; follow with strong solution of common salt and water.

_Other Metallic Poisons_:

Blue vitriol,

Copperas,

Green vitriol,

Sugar of lead,

Corrosive sublimate,

Bedbug poison. Symptoms in general, same as in arsenical poisoning.

With lead and mercury there may be a metallic taste in the

mouth. Emetic with lead; none with copper and iron; white of eggs in

abundance with copper; with iron and lead give epsom salts freely;

afterwards, oils, flour, and water. _No emetic with mercury;_ raw eggs;

milk, or flour, and water. _Phosphorus from_

Matches, rat poisons, etc. Pain in the stomach; vomiting; purging;

general collapse. _Cause vomiting_. Strong soapsuds; magnesia in

water. Never give oils. _Opium:_

Morphine,

Laudanum,

Paregoric,

Dover’s powder,

Soothing syrups,

Cholera and diarrhœa mixtures Sleepiness; dullness; stupor; “pin-hole”

pupils; slow breathing; profuse sweat. _Cause vomiting_. Keep

patient awake by any means, especially by vigorous walking; give strong

coffee freely; dash cold water on face and chest. _Carbolic Acid:_

Creasote. Severe pain in abdomen; odor of carbolic acid, mucous

membrane in around mouth white and benumbed; cold and clammy

skin. _No emetic._ Milk or flour and water; white of eggs.

_Aconite:_

Wolfsbane Monkshood Numbness everywhere, great weakness; cold

sweat. _Vomit patient freely._ Stimulating drinks. _Belladonna_

Deadly Nightshade Atropia Eyes bright, with pupil enlarged; dry mouth

and throat. _Vomit patient freely._ _Various Vegetable Poisons_

Wild parsley,

Indian tobacco,

Toadstools,

Tobacco plant,

Hemlock,

Berries of the Mountain Ash,

Bitter sweet, etc. Stupor, nausea, great weakness and other symptoms

according to the poison. _Cause brisk vomiting_. Stimulating drinks.

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

ingredients.

Bacteria.

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 considerably 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 inhabit.

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 them.

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

species.

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 milk.

Illustration: Fig. 169.—Examples of Pathogenic Bacteria. (Drawn from

photographs.)

A, spiral form of bacteria found in cholera (Magnified about 1000

diameters)

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 general disturbance.

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 poisonous ingredients.

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 people.

Disinfectants.

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 surface wells.

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.[54] _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

fumigation.

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 quantities.[55]

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 of water.[56]

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

follows:

_(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_.

Chapter XV.

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[57]. 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 microscopical work.

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 standard

make.

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.

Additional Experiments.

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

fibers.

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

transparent.

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

flags.

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 veins_.

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 into view.

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_[58] (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. 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.”

Illustration: Fig. 171.

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_ intercostals.

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_.

Illustration: Fig. 172.

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 eye contracts.

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 forefinger.

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 estimated.

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 the other.

To the following syllabus may be added such other similar exercises as

ingenuity may suggest or time permit.

Syllabus.

I. Bony Landmarks.

1. The _occipital protuberance_ can be distinctly felt at the back of

the head. This is always the thickest part (often three-quarters of an

inch or more) of the skull-cap, and is more prominent in some than in

others. The thinnest part is over the temples, where it may be almost

as thin as parchment.

2. The working of the _condyle of the lower jaw_ vertically and from

side to side can be distinctly felt and seen in front of the ear. When

the mouth is opened wide, the condyle advances out of the glenoid

cavity, and returns to its socket when the mouth is shut. In front of

the ear, lies the zygoma, one of the most marked and important

landmarks to the touch, and in lean persons to the eye.

3. The sliding movement of the _scapula_ on the chest can be properly

understood only on the living subject. It can move not only upwards and

downwards, as in shrugging the shoulders, backwards and forwards, as in

throwing back the shoulders, but it has a rotary movement round a

movable center. This rotation is seen while the arm is being raised

from the horizontal to the vertical position, and is effected by the

cooperation of the trapezius with the serratus magnus muscles.

4. The _patella_, or knee-pan, the _two condyles of the tibia_, the

_tubercle on the tibia_ for the attachment of the ligament of the

patella, and the _head of the fibula_ are the chief bony landmarks of

the knee. The head of the fibula lies at the outer and back part of the

tibia. In extension of the knee, the patella is nearly all above the

condyles. The inner border of the patella is thicker and more prominent

than the outer, which slopes down toward its condyle.

5. The short, front edge of the _tibia_, called the “shin,” and the

broad, flat, subcutaneous surface of the bone can be felt all the way

down. The inner edge can be felt, but not so plainly.

6. The head of the _fibula_ is a good landmark on the outer side of the

leg, about one inch below the top of the tibia. Note that it is placed

well back, and that it forms no part of the knee joint, and takes no

share in supporting the weight. The shaft of the fibula arches

backwards and is buried deep among the muscles, except at the lower

fourth, which can be distinctly felt.

7. The _malleoli_ form the great landmarks of the ankle. The outer

malleolus descends lower than the inner. The inner malleolus advances

more to the front and does not descend so low as the outer.

8. The line of the _clavicle_, or collar bone, and the projection of

the joint at either end of it can always be felt. Its direction is not

perfectly horizontal, but slightly inclined downwards. We can

distinctly feel the _spine_ of the scapula and its highest point, the

_acromion_.

9. Projecting beyond the acromion (the arm hanging by the side), we can

feel, through the fibers of the _deltoid_, the upper part of the

humerus. It distinctly moves under the hand when the arm is rotated. It

is not the head of the bone which is felt, but its prominences (the

tuberosities). The greater, externally; the lesser in front.

10. The _tuberosities of the humerus_ form the convexity of the

shoulder. When the arm is raised, the convexity disappears,—there is a

slight depression in its place. The head of the bone can be felt by

pressing the fingers high up in the axilla.

11. The _humerus_ ends at the elbow in two bony prominences (internal

and external condyles). The internal is more prominent. We can always

feel the _olecranon_. Between this bony projection of the ulna and the

internal condyle is a deep depression along which runs the ulna nerve

(commonly called the “funny” or “crazy” bone).

12. Turn the hand over with the palm upwards, and the edge of the

_ulna_ can be felt from the olecranon to the prominent knob (styloid

process) at the wrist. Turn the forearm over with the palm down, and

the head of the ulna can be plainly felt and seen projecting at the

back of the wrist.

13. The upper half of the _radius_ cannot be felt because it is so

covered by muscles; the lower half is more accessible to the touch.

14. The three rows of projections called the “knuckles” are formed by

the proximal bones of the several joints. Thus the first row is formed

by the ends of the metacarpals, the second by the ends of the first

phalanges, and the third by the ends of the second phalanges. That is,

in all cases the line of the joints is a little in advance of the

knuckles and nearer the ends of the fingers.

II. Muscular Landmarks.

1. The position of the _sterno-mastoid_ muscle as an important and

interesting landmark of the neck has already been described (p. 70).

2. If the left arm be raised to a vertical position and dropped to a

horizontal, somewhat vigorously, the tapering ends of the _pectoralis

major_ and the tendons of the _biceps_ and _deltoid_ may be felt by

pressing the parts in the axilla between the fingers and thumb of the

right hand.

3. The appearance of the _biceps_ as a landmark of the arm has already

been described (p. 70). The action of its antagonist, the _triceps_,

may be studied in the same manner.

4. The _sartorius_ is one of the fleshy landmarks of the thigh, as the

biceps is of the arm, and the sterno-cleido-mastoid of the neck. Its

direction and borders may be easily traced by raising the leg,—a

movement which puts the muscle in action.

5. If the model be directed to stand on tiptoe, both of the large

muscles of the calf, the _gastrocnemius_ and _soleus_, can be

distinguished.

6. Direct the model, while sitting upright, to cross one leg over the

other, using his utmost strength. The great muscles of the inner thigh

are fully contracted. Note the force required to pull the legs to the

ordinary position.

7. With the model lying in a horizontal position with both legs firmly

held together, note the force required to pull the feet apart while the

great muscles of the thigh are fully contracted.

8. In forcible and resisted flexion of the wrist two tendons come up in

relief. On the outer side of one we feel the pulse at the wrist, the

radial artery here lying close to the radius.

9. On the outer side of the wrist we can distinctly see and feel when

in action, the three extensor tendons of the thumbs. Between two of

them is a deep depression at the base of the thumb, which the French

call the “anatomical tobacco box.”

10. The relative position of the several extensor tendons on the back

of the wrist and fingers as they play in their grooves over the back of

the radius and ulna can be distinctly traced when the several muscles

are put in action.

11. There are several strong tendons to be seen and felt about the

ankle. Behind is the _tendo Achillis_. It forms a high relief with a

shallow depression on each side of it. Behind both the inner and outer

ankle several tendons can be felt. Over the front of the ankle, when

the muscles are in action, we can see and feel several tendons. They

start up like cords when the action is resisted. They are kept in their

proper relative position by strong pulleys formed by the annular

ligament. Most of these tendons can be best seen by stand a model on

one foot, _i.e._ in unstable equilibrium.

III. Landmarks of the Heart.

To have a general idea of the form and position of the _heart_, map its

outline with colored pencils or crayon on the chest wall itself, or on

some piece of clean, white cloth, tightly pinned over the clothing. A

pattern of the heart may be cut out of pasteboard, painted red, or

papered with red paper, and pinned in position outside the clothing.

The apex of the heart is at a point about two inches below the left

nipple and one inch to its sternal side. This point will be between the

fifth and sixth ribs, and can generally be determined by feeling the

apex beat.

IV. Landmarks of a Few Arteries.

The pulsation of the _temporal_ artery can be felt in front of the ear,

between the zygoma and the ear. The _facial_ artery can be distinctly

felt as it passes over the upper jaw at the front edge of the masseter

muscle. The pulse of a sleeping child can often be counted at the

anterior fontanelle by the eye alone.

About one inch above the clavicle, near the outer border of the

sterno-mastoid, we can feel the pulsation of the great _subclavian_

artery. At the back of the knee the _popliteal_ artery can be felt

beating. The _dorsal_ artery of the foot can be felt beating on a line

from the middle of the ankle to the interval between the first and

second metatarsal bones.

When the arm is raised to a right angle with the body, the _axillary_

artery can be plainly felt beating in the axilla. Extend the arm with

palm upwards and the _brachial_ artery can be felt close to the inner

side of the biceps. The position of the _radial_ artery is described in

Experiment 102.

Glossary.

Abdomen (Lat. _abdo_, _abdere_, to conceal). The largest cavity of the

body, containing the liver, stomach, intestines, and other organs.

Abductor (Lat. _abduco_, to draw from). A muscle which draws a limb

from the middle line of the body, or a finger or toe from the middle

line of the foot or hand.

Absorbents (Lat. _absorbere_, to suck up). The vessels which take part

in the process of absorption.

Absorption. The process of sucking up nutritive or waste matters by the

blood-vessels or lymphatics.

Accommodation of the Eye. The alteration in the shape of the

crystalline lens, which accommodates, or adjusts, the eye for near or

remote vision.