CHAPTER VI.

THE EDUCATION OF THE FIVE SENSES.

If the eye be obstructed, the ear opens wide its portals, and hears

your very emotions in the varying tones of your voice; if the ear be

stopped, the quickened eye will almost read the words as they fall

from your lips; and if both be close sealed up, the whole body

becomes like a sensitive plant--the quickened skin perceives the

very vibrations of the air, and you may even write your thoughts

upon it, and receive answers from the sentient soul within.--ANNUAL

REPORT _of the Trustees of the Perkins Institution and Massachusetts

Asylum for the Blind_, 1841.

He who formed man of the dust of the earth, and breathed into his

nostrils the breath of life, has honored his material organs by

associating them with the immaterial soul. In this life _the senses_

constitute the great conveyances of knowledge to the human mind. It then

becomes not only a legitimate object of inquiry, but one which commends

itself to every human being, and especially to every parent and teacher,

Can these senses be improved by human interference? And if so, how can

that improvement be best effected?

The senses are the interpreters between the material universe without

and the spirit within. Without the celestial machinery of sensation, man

must have ever remained what Adam was before the Almighty breathed into

his form of clay the awakening breath of life. The dormant energies of

the mind can be aroused, and the soul can be put into mysterious

communion with external nature only by the magical power of sensation.

The possession of all the corporeal senses, and their systematic and

judicious culture by all proper appliances, are necessary in order to

place man in such a relation to the material universe and its great

Architect as most fully and successfully to cultivate the varied

capabilities of his nature, and best to subserve the purposes of his

creation. He who is deprived of the healthful exercise of one or more of

his senses, or, possessing them all unimpaired, has neglected their

proper culture, is, from the nature of the case, in a proportionate

degree cut off from a knowledge of God as manifested in his works, and

from that happiness which is the legitimate fruit of such knowledge.

Much light has been thrown upon this subject within a few years by the

judicious labors of that class of practical educators who have devoted

their lives to the amelioration of the condition of persons deprived of

one or more of the senses. It is difficult to conceive the real

condition of the minds of persons thus situated, and especially while

they remain uneducated. He who is deprived of the sense of sight has the

windows of his soul closed, and is effectually shut out from this world

of light and beauty. In like manner, he who is deprived of the sense of

hearing is excluded from the world of music and of speech. What, then,

must be the condition of persons deprived of both of these senses? How

desolate and cheerless! Yet some such there are.

While on a visit to the Asylum for the Blind, in Boston, a few months

ago, I met two of this unfortunate class of persons--Laura Bridgman and

Oliver Caswell. Laura has been several years connected with the

institution.

LAURA BRIDGMAN, _the Deaf, Dumb, and Blind Girl_.--So remarkable is the

case of this interesting girl, so full of interest, so replete with

instruction, and in every way so admirably adapted to illustrate the

subject of this chapter, that I proceed to give to my readers a sketch

of the method pursued in her instruction, together with the results

attendant upon it. My information in relation to her is derived from

both personal acquaintance and the reports of her case, though

principally from the latter source.

Laura was born in Hanover, New Hampshire, on the 21st of December, 1829.

She is described as having been a very sprightly and pretty infant.

During the first years of her existence she held her life by the

feeblest tenure, being subject to severe fits, which seemed to rack her

frame almost beyond the power of endurance. At the age of four years her

bodily health seemed restored; but what a situation was hers! The

darkness and silence of the tomb were around her. No mother's smile

called forth her answering smile. No father's voice taught her to

imitate his sounds. To her, brothers and sisters were but forms of

matter which resisted her touch, but which hardly differed from the

furniture of the house save in warmth and in the power of locomotion,

and not even in these respects from the dog and the cat. But the

immortal spirit implanted within her could not die, nor could it be

maimed or mutilated; and, though most of its avenues of communication

with the world were cut off, it began to manifest itself through the

others. As soon as she could walk, she began to explore the room, and

then the house. She thus soon became familiar with the form, density,

weight, and heat of every article she could lay her hands upon. She

followed her mother, and felt of her hands and arms, as she was occupied

about the house, and her disposition to imitate led her to repeat every

thing herself. She even learned to sew a little and to knit.

Her affections, too, began to expand, and seemed to be lavished upon the

members of her family with peculiar force. But the means of

communication with her were very limited. She could be told to go to a

place only by being pushed, or to come to one by a sign of drawing her.

Patting her gently on the head signified approbation, on the back

disapprobation. She showed every disposition to learn, and manifestly

began to use a natural language of her own. She had a sign to express

her idea of each member of the family, as drawing her fingers down each

side of her face to allude to the whiskers of one, twirling her hand

around in imitation of the motion of a spinning-wheel for another, and

so on. But, although Laura received all the aid a kind mother could

bestow, she soon began to give proof of the importance of language in

the development of human character. By the time she was seven years old

the moral effects of her privation began to appear, for there was no way

of controlling her will but by the absolute power of another, and at

this humanity revolts.

At this time, Dr. Samuel G. Howe, the distinguished and successful

director of the asylum, learned of her situation, and hastened to see

her. He found her with a well-formed figure, a strongly-marked

nervous-sanguine temperament, a large and beautifully shaped head, and

the whole system in healthy action. Here seemed a rare opportunity of

trying a plan for the education of a deaf and blind person, which the

doctor had formed on seeing Julia Brace at Hartford. The parents readily

consented to her going to the institution in Boston, where Laura was

received in October, 1837, just before she had completed her eighth

year. For a while she was much bewildered. After waiting about two

weeks, and until she became acquainted with her new locality, and

somewhat familiar with the inmates, the attempt was made to give her a

knowledge of arbitrary signs, by which she could interchange thoughts

with others. One of two methods was to be adopted. Either the language

of signs, on the basis of the natural language she had already commenced

herself, was to be built up, or it remained to teach her the purely

arbitrary language in common use. The former would have been easy, but

very ineffectual. The latter, although very difficult, if accomplished,

would prove vastly superior. It was therefore determined upon.

The _blind_ learn to read by means of raised letters, which they gain a

knowledge of by the sense of feeling. _The ends of the fingers_, resting

upon the raised letters, thus constitute, in part, _the eyes of the

blind_. This, although apparently difficult, becomes comparatively easy

when the blind person possesses the _sense of hearing_, and is thus

enabled to become acquainted with spoken language. On the contrary, the

_deaf_, and consequently _dumb_, are unable to acquire a knowledge of

spoken language so as to use it with any degree of success. In their

education, hence, the _language of signs_, which can be addressed to the

eye, is substituted for spoken language. In communicating with one

another, by means of the _manual alphabet_, they substitute positions

of the hand, which they can both make and see, for letters and words,

which they can neither pronounce nor hear.

To be deprived of either sight or hearing was formerly regarded as an

almost insuperable obstacle in the way of education. Persons deprived of

both these senses have heretofore been considered by high legal

authorities,[23] as well as by public opinion, as occupying, of

necessity, a state of irresponsible and irrecoverable idiocy. By the

education of the remaining senses, however, this formidable and

heretofore insuperable barrier has been overleaped, or, rather, the

obstacle has been met and overcome. The experiment has been successfully

tried, once and again, in our own country. The deaf and blind mute has

not only acquired a knowledge of reading and writing, and of the common

branches of education, but has been enabled successfully to prosecute

the study of natural philosophy, of mental science, and of geometry. The

accomplishment of all this has resulted from the successful cultivation

of the sense of touch or of feeling. The raised letter of the blind has

been used for written language, and the manual language of the mute,

taken by the _finger-eyes_ of the blind, has been successfully

substituted for spoken language.

[23] A man is not an idiot if he hath any glimmering of reason, so that

he can tell his parents, his age, or the like matters. But a man who is

born deaf, dumb, and blind, is looked upon by the law as in the same

state with an idiot, he being supposed incapable of any understanding,

as wanting all the senses which furnish the human mind with

ideas.--_Blackstone's Commentaries_, vol. i., p. 304.

Laura's mind dwelt in darkness and silence. In order, therefore, to

communicate to her a knowledge of the arbitrary language in common use,

it was necessary to combine the methods of instructing the blind and

the deaf. The first experiments in instructing her were made by taking

articles in common use, such as knives, forks, spoons, keys, etc., and

pasting upon them labels with their names printed in _raised letters_.

These she felt of very carefully, and soon, of course, distinguished

that the crooked lines ~_spoon_~ differed as much from the crooked lines

~_key_~, as the spoon differed from the key in form. Small detached

labels, with the same words printed upon them, were then put into her

hands, and she soon observed that they were similar to those pasted on

the articles. She showed her perception of this similarity by laying the

label ~_key_~ upon the key, and the label ~_spoon_~ upon the spoon. When

this was done she was encouraged by the natural sign of

approbation--patting on the head.

The same process was then repeated with all the articles which she could

handle, and she very easily learned to place the proper labels upon

them. After a while, instead of labels, the individual letters were

given to her, on detached bits of paper. These were at first arranged

side by side, so as to spell ~_book_~, ~_key_~, &c. They were then mixed

up, and a sign was made for her to arrange them herself, so as to express

the words ~_book_~, ~_key_~, etc., and she did so.

The process of instruction, hitherto, had been mechanical, and the

success attending it about as great as that in teaching a very knowing

dog a variety of tricks. The poor child sat in mute amazement, and

patiently imitated every thing her teacher did. Presently the truth

began to flash upon her; her intellect began to work; she perceived that

here was a way by which she could herself make up a sign of any thing

that was in her own mind, and show it to another mind, and at once her

countenance lighted up with a human expression! her immortal spirit

eagerly seizing upon a new link of union with other spirits! Dr. Howe

says he could almost fix upon the moment when this truth dawned upon her

mind and spread its light to her countenance. He saw at once that

nothing but patient and persevering, but judicious efforts were needed

in her instruction, and that these would most assuredly be crowned with

success.

It is difficult to form a just conception of the amount of labor

bestowed upon Laura thus far. In communicating with her, spoken language

could not be used, for she was destitute of hearing. Neither are signs

of any use when addressed to the eyes of the blind. When, therefore, it

was said that "a sign was made," we are to understand by it that the

action was performed by her teacher, she feeling of his hands, and then

imitating the motion. The next step in the process of her instruction

was to procure a set of metal types, with the different letters of the

alphabet cast upon their ends; also a board, in which were square holes,

into which she could set the types so that the letters on the end could

alone be felt above the surface. Then, on any article being handed to

her whose name she had learned--a pencil or a watch, for instance--she

would select the component letters and arrange them on her board, and

read them with apparent pleasure.

When she had been exercised in this way for several weeks, and until her

knowledge of words had become considerably extensive, the important step

was taken of teaching her how to represent the different letters by the

position of her fingers, instead of the cumbrous apparatus of the board

and types. This she accomplished speedily and easily, for her intellect

had begun to work in aid of her teacher, and her progress was rapid.

Six months after Laura had left home her mother went to visit her. The

scene of their meeting was full of interest. The mother stood some time

gazing with overflowing eyes upon her unfortunate child, who, all

unconscious of her presence, was playing about the room. Presently Laura

ran against her, and at once began feeling of her hands, examining her

dress, and trying to find out if she knew her; but, not succeeding in

this, she turned away as from a stranger, and the poor woman could not

conceal the pang she felt at finding her beloved child did not know her.

She then gave Laura a string of beads which she used to wear at home.

These were at once recognized by the child, who gave satisfactory

indications that she understood they were from home. The mother now

tried to caress her; but Laura repelled her, preferring to be with her

acquaintances.

Other articles from home were then given to Laura, and she began to look

much interested; she examined the stranger much closer, and gave the

doctor to understand she knew they came from Hanover; she now even

endured her mother's caresses, but would leave her with indifference at

the slightest signal. After a while, on the mother taking hold of her

again, a vague idea seemed to flit across Laura's mind that this could

not be a stranger; she therefore felt of her hands very eagerly, while

her countenance assumed an expression of intense interest; she became

very pale, and then suddenly red; hope seemed struggling with doubt and

anxiety, and never were contending emotions more strongly painted upon

the human face. At this moment of painful uncertainty, the mother drew

Laura close to her side, and kissed her fondly, when at once the truth

flashed upon the child, and all distrust and anxiety disappeared from

her face. With an expression of exceeding joy, Laura nestled to the

bosom of her parent, and yielded herself to her fond embraces. After

this the beads were all unheeded, and the playthings which were offered

to her were utterly disregarded. Her playmates, for whom she but a

moment before left the stranger, now vainly strove to pull her from her

mother. The meeting and subsequent parting showed alike the affection,

the intelligence, and the resolution of the child as well as of her

mother.

The following facts are drawn from the report made of her case at the

end of the year 1839, after she had been a little more than two years

under instruction. Having mastered the manual alphabet of the deaf

mutes, and having learned to spell readily the names of every thing

within her reach, she was then taught words expressive of positive

qualities, as hardness and softness. This was a very difficult process.

She was next taught those expressions of relation to place which she

could understand. A ring, for example, was taken and placed _on_ a box;

then the words were spelled to her, and she repeated them from

imitation. The ring was afterward placed _on_ a hat, desk, etc. In a

similar manner she learned the use of _in_, _into_, etc. She would

illustrate the use of these and other words as follows: She would spell

~_on_~, and then lay one hand _on_ the other; then she would spell

~_into_~, and inclose one hand _within_ the other.

Laura very easily acquired a knowledge and use of active verbs,

especially those expressive of _tangible action_, as to walk, to run, to

sew, to shake. In acquiring a knowledge of language, she used the words

with which she had become acquainted in a general sense, and according

to the order of _her sense of ideas_. Thus, in asking some one to give

her bread, she would first use the word expressive of the leading idea,

and say, _Bread, give, Laura_. If she wanted water, she would say,

_Water, drink, Laura_.

Having acquired the use of substantives, adjectives, verbs,

prepositions, and conjunctions, it was thought time to make the

experiment of trying to teach her to _write_, and to show her she might

communicate her ideas to persons not in contact with her. It was amusing

to witness the mute amazement with which she submitted to the process;

the docility with which she imitated every motion, and the perseverance

with which she moved her pencil over and over again in the same track,

until she could form the letter. But when at last the idea dawned upon

her that by this mysterious process she could make other people

understand what she thought, her joy was boundless! Never did a child

apply more eagerly and joyfully to any task than she did to this; and in

a few months she could make every letter distinctly, and separate words

from each other.

At this time Laura actually wrote, unaided, a legible letter to her

mother, in which she expressed the idea of her being well, and of her

expectation of going home in a few weeks. It was, indeed, a very rude

and imperfect letter, couched in the language which a prattling infant

would use. Still, it shadowed forth and expressed to her mother the

ideas that were passing in her own mind. She had attained about the same

command of language as common children three years of age. But her power

of expression was, of course, by no means equal to her power of

conception; for she had no words to express many of the perceptions and

sensations which her mind doubtless experienced. In the spring of 1840,

when she had been under instruction about two and a half years,

returning fatigued from her journey home, she complained of a pain in

her side, and on being asked what caused it, she replied as follows:

"Laura did go to see mother, ride did make Laura side ache, horse was

wrong, did not run softly." Her improvement in the use of language was

very rapid, and she soon became, in some respects, quite a critic. When

one of the girls had the mumps, Laura learned the name of the disease;

soon after she had it herself, but she had the swelling only on one

side; and some one saying to her, "You have got the mumps," she replied

quickly, "_No, no; I have mump._"

About this time Laura learned the difference between the present and

past tense of the verb. And here her simplicity rebukes the clumsy

irregularities of our language. She learned _jump, jumped_--_walk,

walked_, etc., until she had an idea of the mode of forming the

imperfect tense of regular verbs; but when she came to the word _see_,

she insisted that it should be _seed_ in the imperfect; and upon going

down to dinner, she asked if it was _eat, eated_; but being told it was

_eat_, ATE, she seemed to try to express the idea that this

transposition of the letters was not only wrong, but ludicrous, for she

laughed heartily. She continued this habit of forming words

analogically. When she had become acquainted with the meaning of the

word restless, she seemed to understand that _less_ at the end of a word

means without, destitute of, or wanting, as rest-less, fruit-less; also

that _ful_ at the end of a word expresses abundance of what is implied

by the primitive, as bliss-ful, play-ful. This is clearly illustrated in

the following expressions. One day, feeling weak, she said, "I am very

strongless." Being told this was not right, she said, "Why, you say

restless when I do not sit still." Then she said, "I am very weakful."

My primary object in referring to Laura has been to illustrate, in a

striking manner, the practicability of the education of the senses to

an extent not heretofore generally known. To such an extent has the

sense of touch been cultivated in her, that her fingers serve as very

good substitutes for both eyes and ears. I will mention one or two

instances which strikingly illustrate the acuteness of Laura's sense of

touch. When I was at the institution a few months ago, she was told a

person was present whom she had never met, and who wished an

introduction to her. She reached her hand, expecting to meet a

_stranger_. By mistake (for her teachers design never to allow her to be

deceived), she took the hand of another gentleman, whom she recognized

immediately, though she had never met him but twice before. She

recognizes her acquaintances in an instant by touching their hands or

their dress, and there are probably hundreds of individuals who, if they

were to stand in a row, and hold out each a hand to her, would be

recognized by that alone. The memory of these sensations is very vivid,

and she will readily recognize a person whom she has once thus touched.

Many cases of this kind have been noticed; such as a person shaking

hands with her, and making a peculiar pressure with one finger, and

repeating this on his second visit, after a lapse of many months, being

instantly known by her. She has been known to recognize persons with

whom she had thus simply shaken hands but once, after a lapse of six

months. But this is hardly more wonderful than that one should be able

to recall impressions made upon the mind through the organ of sight, as

when we recognize a person of whom we have had but one glimpse a year

before; but it shows the exhaustless capacity of those organs which the

Creator has bestowed, as it were, in reserve against accidents, and

which we too commonly allow to lie unused and unvalued.

OLIVER CASWELL.--Had I not devoted so much space to this subject

already, it would be interesting to consider the case of Oliver, who,

like Laura, is deaf, dumb, and blind. His experience is full of

interest, though less striking than that already presented. His progress

in learning language, and in acquiring intellectual knowledge, is

comparatively slow, because he has not that fineness of fiber and that

activity of temperament which enable Laura to struggle so successfully

against the immense disadvantages under which they both labor. Oliver is

a boy of rather unfavorable organization; he had been deaf and blind

from infancy; he received no instruction until he was twelve years old,

and consequently lost the most precious years for learning; he has

nevertheless been taught to express his thoughts both by the finger

language and by writing; he has also become acquainted with the

rudiments of the common branches of education, and is intelligent and

morally responsible. His case proves, therefore, very clearly, that the

success of the attempt made to instruct Laura Bridgman was not owing

solely to her uncommon capacity.

Oliver's natural ability is small, and his acquired knowledge very

limited; but his sense of right and wrong, his obedience to moral

obligations, and his attachment to friends, are very remarkable.[24] He

never willfully violates the rights or injures the feelings of others,

and seldom shows any signs of temper when his own seem to be invaded. He

even bears the teasing of little boys with gentleness and patience. He

is very tractable, and always obeys respectfully the requests of his

teacher. This shows the effect which kind and gentle treatment has had

upon his character, for when he first went to the institution in Boston

he was sometimes very willful, and showed occasional outbursts of temper

which were fearfully violent. "It seems hardly possible," says Dr. Howe,

"that the gentle and affectionate youth, who loves all the household and

is beloved by all in return, should be the same who a few years ago

scratched and bit, like a young savage, those who attempted to control

him."

[24] I have omitted much in the case of Laura that I should have

retained but for want of room. The moral qualities of her nature have

developed themselves most clearly. She is honest to a proverb, having

never been known to take any thing belonging to another. That she is a

Christian there can be no doubt. It is said in the report of her case

for 1846, that "on the last occasion of her manifesting any impatience,

she said to Miss Wight, her teacher, '_I felt cross, but in a minute I

thought of Christ, how good and gentle he was, and my bad feelings went

away._'"

We regard it as a fact fully established that the sense of touch may be

cultivated to a much greater extent than most persons are aware of. The

same remark will apply to the cultivation of all the senses. We shall

consider them separately.

THE SENSE OF TOUCH.--The remarks already made apply chiefly to this

sense. The nerves that supply it proceed from the anterior half of the

spinal cord. This sense is most delicate where there are the greatest

number of nervous filaments, and those of the largest size. The hands,

and especially the fingers, have a most delicate and nice sense of

touch, though the sense is extended over the whole body, in every part

of which it is less or more acute. In this respect, then, this sense is

unlike the others, which are confined to small spaces, as we shall see

when we come to consider them. The action of the sensitive nerves

depends upon the state of the brain, and the condition of the system

generally. In sound and perfect sleep, when the brain is inactive,

ordinary impressions made upon the skin are unobserved. Fear and grief

diminish the impressibility of this tissue, while hope and joy increase

it. The quantity and quality of the blood also influence sensation. If

this vital fluid becomes impure, or its quantity is diminished, the

sensibility of the skin will be impaired thereby. Whatever affects the

general health affects the healthy action of this sense. It is also much

affected by sudden changes in temperature. If the skin is wounded while

under the influence of cold, the pain will be slight. By carrying this

chilling influence too far, the surface becomes entirely destitute of

sensation. This is produced by the contraction of the blood-vessels upon

the surface. On the contrary, when the chilled extremities are suddenly

exposed to heat, the rapid enlargement of the contracted blood-vessels

excites the nerves unduly, which causes the pain experienced on such

occasions.

The sensibility of the nerves depends much upon the habits of persons.

Suppose two boys go out to play when the thermometer stands at the

freezing point, and that one of them has been accustomed to exercise in

the open air, and to practice daily ablution, while the other one has

been confined most of the time to a warm room, and has been accustomed

to wash only his hands and face. The skin of the former, other things

being equal, will be active and healthy, while that of the latter will

be enfeebled and diseased. The organs of touch diffused over the body at

the surface will be very differently affected in these two boys, and the

perceptions of their minds will be alike dissimilar. One will be roused

to action, and will feel just right for some animating game. Both body

and mind will be elastic and joyous. He will bound like the roe, make

the welkin ring with his merry shout, and return to the bosom of his

family with a gladdened heart, ready to impart and receive pleasure,

while the other boy will be too keenly affected by the contact of the

air, and think it too cold to stay out of doors. He will thrust his

hands into his pockets, and curl himself up like one decrepit with age.

His teeth will chatter and his whole frame tremble. Of course, very

different reflections will be awakened in his mind. He will hurry back

to the fireside, thinking winter a very dismal season, and will be apt

to fret himself and all about him, because of the confinement from which

he has not the resolution to break out.

The sensibility of the cutaneous nerves in these two cases depends upon

the habits of the persons. If the latter would practice frequent

ablutions, and excite a healthy action in the skin by friction and

exercise, and conform to other laws of health, he would experience all

that gladness of heart, and elasticity of body and mind, which the other

is supposed to enjoy. Hence the advantages resulting from a strict

conformity to the laws of health in this particular as well as in others

that are generally regarded as more important.

The general law that the exercise of a faculty increases its power is

applicable to the senses. We have referred to the blind, who read as

rapidly as seeing persons by passing their fingers over raised letters,

the sense of touch being substituted by them for that of vision. Nor is

the education of this sense useful to the blind merely. It may

frequently be appealed to with great advantage by all who have

cultivated it. The miller, for example, can judge more accurately of the

quality of flour and meal, by passing some between his fingers than by

the exercise of vision. The cloth-dresser, also, by the aid of this

sense, not only marks the nicest shades of texture in examining cloths

of different qualities, but in many instances learns to distinguish

_colors_ by the sense of touch with perhaps greater accuracy than is

common with seeing persons.

THE SENSE OF TASTE.--The sense of taste bears the greatest resemblance

to the sense of feeling. The upper surface of the tongue is the

principal agent in tasting, though the lips, the palate, and the

internal surface of the cheeks participate in this function, as does the

upper part of the oesophagus. The multitude of points called papillae,

scattered over the upper surface of the tongue, constitute the more

immediate seat of this sense. It is in these sensitive papillae that the

ramifications of the gustatory or tasting nerves terminate. When fluids

are taken into the mouth, and especially those whose taste is pungent,

these papillae dilate and erect themselves, and the particular sensation

produced is transmitted to the brain through the medium of the minute

filaments of the gustatory nerves.

In order fully to gratify the taste in eating dry, solid food, it is

necessary that the food be first reduced to a liquid state, or, at

least, that it be thoroughly moistened. Nature has made full provision

for this in furnishing the mouth with salivary glands, whose secretions

are most abundant when engaged in masticating dry, hard substances.

These quickened secretions contribute to gratify the taste and increase

the pleasure of eating, and, at the same time, materially aid in the

important processes of mastication and digestion. Nature, also, with her

accustomed bounty, has furnished man with a great variety of articles

for food. By this means the various tastes of different persons may be

gratified, although, in many instances, those articles of food which are

most agreeable to some persons are extremely disagreeable to others.

Many persons can not eat the most nourishing food, as fruits, butter,

etc., because to them the taste of these articles is disagreeable. But

this is very easily accounted for, as in the mouth the food mixes with

various fluids that differ in different persons, and in the same person

at different times. These fluids, and particularly the saliva, assist in

the formation and change of taste. This accounts not only for the

different tastes of different persons, but also for the varying taste of

the same persons, and for that fickleness of taste which is so common in

sickness, when the fluids of the mouth, in a disordered and deranged

state, mix with the food, and produce the disagreeable taste so often

complained of at such times, and which, moreover, occasionally create a

permanent dislike for food that was previously much relished.

This sense was given to men and animals to guide them in the selection

of their food, and to enable them to guard against the use of articles

that would be injurious if introduced into the stomach. In the inferior

animals, the sense of taste still answers the original design of its

bestowment; but in man, it has been abused and perverted by the use of

artificial stimulants, which have created an acquired taste that, in

most persons, is very detrimental to health. This sense is so modified

by habit, that, not unfrequently, articles which were at first

exceedingly offensive, become, at length, highly agreeable. It is in

this manner that many persons, whose sense of taste has been impaired or

perverted, have formed the disgusting and ruinous habits of smoking and

chewing tobacco, and of using stimulating and intoxicating drinks. But

these pernicious habits, and all similar indulgences, lessen the

sensibility of the gustatory nerve, and ultimately destroy the natural

relish for healthful food and drink. By this means, also, the digestive

powers become disordered, and the general health is materially impaired.

All persons, then, should seek to preserve the natural integrity of

this sense, and to restore it immediately to healthy action when at all

depraved, for upon this depends much of health and longevity, of

happiness and usefulness.

This sense may be rendered very acute by cultivation, as is illustrated

by persons who are accustomed to taste medicines, liquors, teas, etc. It

ought, however, to be chiefly exercised in partaking of those simple

articles of food and drink which are most conducive to health. In its

natural state it prefers these, and if depraved it will soon recover a

healthy tone, if not continually tempted by stimulating substances. This

is beautifully illustrated in thousands of instances all over our

country by persons who were once accustomed to use strong drink, but who

have substituted for it sparkling water, a beverage prepared by God

himself to nourish and invigorate his creatures, and beautify his

footstool.

THE SENSE OF SMELL.--The sense of taste has received a faithful

companion in that of smell. The beneficent Creator, with that wisdom

which characterizes all his works, has very wisely placed the organ of

this sense just above the mouth, in order that the scent of many things

that are hurtful may warn us from partaking of them before they reach

the mouth. The air-passages of the nose, in which this sense is located,

are lined with a thin skin, called the mucous membrane, which is

continuous with the lining membrane of the parts of the throat and of

the external skin. Upon this membrane the olfactory nerve ramifies. The

odoriferous particles of matter that float in the air come in contact

with these fine and sensitive nerves as the air rushes through the

nostrils, and the impression is conveyed to the brain by the olfactory

nerve. The mucous membrane, upon which this ramifies, is of

considerable extent in man. In the lower animals it is less or more

extensive, according to the degree of acuteness of this sense. This

membrane is full of little glands that are continually giving off thick

mucus, and especially when the membrane is inflamed. There is a small

canal leading from the eyes to the nose, through which a fluid, that

also forms tears, is constantly passing when the passage is clear. It is

the office of this fluid to moisten and thin the mucus of the nose. When

this mucous is too abundant, as in some stages of a cold, and especially

if it becomes dry from the closing of the canal leading from the eyes,

or from any other cause, as fever, the sense of smell will be greatly

impaired, if not entirely suspended. It is, indeed, not unfrequently

permanently injured in this way, and sometimes is irrecoverably lost.

The sensation of smell, it should be borne in mind, is produced by a

kind of odoriferous vapor, very fine and invisible, that flies off from

nearly all bodies. The air which contains this vapor is drawn into the

nose, and is in this way brought into contact with the very delicate

nerves of smell that ramify the membrane which lines the air-passages of

this organ. It is only when the exceedingly small particles of which the

odor of various bodies is composed come in contact with the minute

ramifications of the olfactory nerve that this sensation is produced. In

order to protect these sensitive nerves, as well as to prevent the

introduction into the lungs of injurious substances, the air-passages of

the nose are furnished with hairy appendages, which are less or more

abundant according to the size of these passages. These intercept any

foreign substances that enter the nose, and thus irritate the mucous

membrane, and cause a quick and powerful contraction of the diaphragm,

by which the offending matter is immediately expelled. This phenomenon,

which is called sneezing, depends upon a connection of the olfactory

with the respiratory nerves.

This sense not only comes in to the aid of taste in enabling man and the

lower animals to select proper food, and avoid that which is injurious,

but it also gives us positive and varied pleasure by the inhalation of

agreeable odors, while, at the same time, it enables us to avoid an

infectious atmosphere, and all objects whose odors are offensive and

hurtful.

It is true that man can accustom himself to nearly all kinds of odor,

even to those that at first are very disagreeable. He indeed not

unfrequently so vitiates the sense of smell as actually to prefer those

scents which, to persons who have preserved the integrity of this sense,

are regarded as exceedingly offensive, and even filthy. But why, let me

ask, did the Creator give us the sense of smell? Was it to be thus

perverted? No, indeed: it was, without doubt, that we might enjoy the

refreshing fragrance of flowers and herbs, of food and drink; and also

that we might distinguish between air that is pure and healthful, and

that which is impure and infectious. As most articles of food which are

agreeable to the smell are wholesome, and as those which are

disagreeable are generally unwholesome, so, also, those states of the

atmosphere which are grateful to this sense are salubrious, and those

odors which are pleasant are healthful, while air which is ungrateful

will generally be found injurious to health, as will also all those

odors which are unpleasant to this sense when in a healthful state. He

who has had occasion to enter a crowded court-room, lecture-room,

church, or assembly-room of whatever kind, which has been occupied for a

considerable time without adequate ventilation, can not fail to remember

the unwelcome impression made upon his nasal organs when first he

inhaled the vitiated atmosphere within, though by degrees he might have

become accustomed to it, did he remain, so as ultimately to become

well-nigh insensible to its noisome influence. But let such and all

others be well assured that, however offensive such a fetid atmosphere

may be to the smell, it is equally injurious to the health. And let

those who, having returned from a morning walk or healthful exercise in

a salubrious atmosphere, have had occasion to revisit the small and

unventilated lodging-room in which they spent a restless night without

refreshing sleep, perceive, in the sickening smell, a sufficient cause

for all their pains and aches, and wonder how they survived such a gross

violation of the organic laws.

All of the senses may be improved by education. The sense of smell

constitutes no exception to this rule. Let none be discouraged, then;

for the more we accustom our lungs and nasal organs to pure air, the

more will they require it, and the more readily will they detect the

presence of the least impurity.

This sense becomes very acute in deaf persons, and even more so in the

case of those that are blind. The reason is obvious; for, as they are

led of necessity to rely upon it more than persons who have all the

senses, it becomes thereby developed, and is enabled more accurately to

judge of the properties of whatever is submitted to its scrutiny. Seeing

persons rarely partake of any article of food, and especially of any

thing new, without first smelling it, and blind persons never; for this

is the only means by which they can judge of its wholesomeness or

unwholesomeness without tasting it.

Whatever stupefies the brain, impairs the healthy action of the nerve of

smell, or thickens the membrane that lines the nasal cavities, and thus

diminishes the sensibility of the nerves ramified upon it, injures this

sense. All these effects are produced by the habitual use of snuff,

which, when introduced into the nose, diminishes the sensibility of the

nerves, and thickens the lining membrane. By its use the air-passages

through the nostrils sometimes become completely obstructed. It is on

this account that most habitual snuff-takers are compelled to open their

mouths in order to breathe freely. It has been well said, that if Nature

had intended that the nose should be used as a snuff-hole, she would

doubtless have put it on the other end up.

THE SENSE OF HEARING.--The external ear, although curiously shaped, is

not the most important part of the organ whose function it is to take

cognizance of sounds. In the transmission of sound to the brain, the

vibrations of the air produced by the sonorous body are collected by the

external ear, and conducted through the auditory canal to the drum of

the ear, which is so arranged that it may be relaxed or tightened like

the head of an ordinary drum. That its motion may be free, the air

contained within the drum has free communication with the external air

by an open passage, called the Eustachian tube, leading to the back of

the mouth. This tube is sometimes obstructed by wax, when a degree of

deafness ensues. But when the obstruction is removed in the effort of

sneezing or otherwise, a crack or sudden noise is generally experienced,

accompanied usually with an immediate return of acute hearing.

The ear-drum performs a two-fold office; for while it aids in the

transmission of sound from without to the internal ear, it at the same

time modifies the intensity of sound. This softening of the sound is

effected by the relaxation of a muscle when sounds are so acute as to be

painful; but when listening to low sounds, the drum is rendered tense

by the contraction of this muscle, and the sounds become, by this means,

more audible. The vibrations made on the drum are transmitted by the

tympanum--an irregular bony cavity--to the internal ear, which is filled

with a watery fluid. In this fluid the filaments of the auditory nerve

terminate, which receive and transmit the sound to the brain.

The ear has the power of judging of the direction from which sound

comes, as is strikingly exemplified in the fact that when horses or

mules march in company at night, those in front direct their ears

forward, and those in the rear turn them backward, while those in the

center turn them laterally or across, the whole troop seeming to be

actuated by a feeling to watch the common safety. This is also

illustrated by four or six horse teams, and is a fact with which

coachmen are familiar. It is further illustrated by the dog, and many

other animals. The external ear of man is likewise furnished with

muscles; and savages are said to have the power of moving or directing

their ears at pleasure, like a horse, to catch sounds as they come from

different directions; but few men in civilized life retain this power.

The acuteness of this sense in men and animals, other things being

equal, depends upon the size of the ear. In timid animals, as the hare

and the rabbit, the ear is very large. They are thus apprized of the

approach of an enemy in time to flee to a place of safety.

The ear-trumpet--which is a tube wide at one end, where the sound

enters, and narrow at the other, where the ear is applied--is

constructed on this principle, its sides being so curved that, according

to the law of reflection, all the sound which enters it is brought to a

focus in the narrow end. It thus increases many fold the intensity of a

sound which reaches the ear through it, and enables a person who has

become deaf to common conversation to mix again with pleasure in

society. The concave hand held behind the ear answers in some degree the

purpose of an ear-trumpet.

_The Ear of Dionysius_, in the dungeons of Syracuse, was a notorious

instance of a sound-collecting surface. The roof of the prison was so

formed as to collect the words, and even whispers, of the unhappy

prisoners, and to direct them along a hidden conduit to where the tyrant

sat listening.

Acuteness of hearing requires the healthy action of the brain, and

particularly of that portion of it from which the auditory nerve

proceeds, combined with perfection in the structure and functions of the

different parts of the ear. The best method, then, of retaining and

improving the hearing, is to observe well the general laws of health,

and particularly to avoid every thing that will in the least impair the

structure or healthy action of the parts immediately concerned in the

exercise of this function. Inflammatory fevers, affections of the brain,

and injuries upon the head, are among the more common causes of

imperfect hearing. Hence the impropriety of striking children upon the

head in correcting them, whether in the family or in the school. The

instances are not few in which deafness, and the impairing of the mental

faculties, have resulted from that barbarous practice familiarly known

as "boxing the ears." This inhuman practice is likely to result in

injury to the drum of the ear, either in thickening this membrane, or in

diminishing its vibratory character. Inflammation of the ear-drum,

either acute or chronic, is the common cause of its increased thickness.

How often this is produced by blows, the reader may judge. Diminution of

the vibratory character of the ear-drum may result from an accumulation

of wax upon its outer surface. In such cases chronic inflammation of

the parts is not unfrequently the result of the injudicious practice of

attempting its removal by introducing the heads of pins into the ear.

This wax, it should be known, is designed to subserve an important end;

for the tube leading from the external ear, being, like the nose,

constantly open, is liable to the entrance of foreign bodies, such as

dust, insects, and the like. But, fortunately, it is not left without

the means of defense; for on its inside there are numerous fine

bristles, which, interlacing each other, interpose a barrier to the

entrance of every thing but sound. Moreover, between the roots of these

hairs there are numerous little glands, that secrete a nauseous, bitter

wax, which, by its offensiveness, either deters insects from entering,

or entangles them and prevents their advance in case they do enter. This

wax, then, is very serviceable. But its usefulness does not stop here.

When the ear becomes dry from a deficiency of it, the hearing becomes

imperfect, as also when it is thin and purulent. This wax not

unfrequently becomes hard and obstructs the tube, causing less or more

deafness. But this form of deafness may be easily cured, even though it

has existed for years; for, having softened the accumulations of viscid

wax by dropping animal oil into the ear, they may be removed by the

injection of warm soap-suds, which is an effectual and safe remedy.

The sense of hearing is perhaps as susceptible of cultivation as any of

the senses. The Indian in the forest, who is accustomed to listen to the

approach of his enemies or of his prey, acquires such acuteness of

hearing as to be able to detect sounds that would be inaudible to

persons living amid the din of civilized life. The blind, also, who of

necessity are led to rely more upon this sense than seeing persons,

excel in the acuteness of their hearing. They recognize their

acquaintances by the exercise of this sense as readily as persons

usually do by that of sight, an attainment which very few seeing persons

make, and yet one that is perhaps within the reach of ninety-nine

persons in every hundred. The blind judge with great accuracy the

distance of persons in conversation, of carriages in motion, and of all

sonorous bodies whose vibrations reach their ears. They even estimate

with remarkable correctness the distance and height of buildings by the

reflection or interception of sound. It is in consequence of the

acuteness of this sense, acquired by careful cultivation, that the

blind, as a class, have become so generally and justly distinguished for

their pre-eminence in instrumental music. This enables them also to

cultivate vocal music with more than ordinary success.

The due cultivation of the sense of hearing will contribute vastly to

promote our intellectual and moral well-being. If it be true, as we are

told it is by those who have been engaged in teaching both the deaf and

the blind, that the absence of hearing is even a more formidable

impediment to the communication of knowledge than that of sight, we must

infer that all imperfections of the organ of hearing itself, or in the

manner of using it, must correspondingly lessen the accuracy of the

knowledge we receive through that organ. The meaning of language very

often is conveyed not so much by the words themselves as in the tones of

voice in which the words are uttered. If, therefore, the hearing be

indistinct, or there be no habit formed of careful attention to the

inflections of sound, the impressions received from what we hear must

often be inaccurate. Our speech, too, will be far less agreeable, and be

inefficient, even if it be not positively inarticulate. We owe it to

others, no less than to ourselves, then, to cultivate the powers of the

voice--the common instrument that God has given us for the interchange

of thought, sentiment, and feeling, and which, though so common, is the

most perfect of all instruments for the transmission of sound. Yet how

deplorably is it neglected! how shamefully is it misused! It can be

fully developed and made what it is capable of being only through the

influence of the ear. If this organ be neglected, the voice must needs

be imperfect. And the voices of many persons are through life imperfect

and disagreeable, because they were not carefully trained in early life

to articulate distinctly, much less to utter _musical_ sounds. The

opinion is confidently expressed by those who are best qualified to

decide the matter, that nearly all children might be taught to sing, if

proper attention were paid early enough to the use they make of their

ears and their organs of sound. The careful training of these should be

considered an indispensable part of a school-teacher's as well as of a

parent's duty.

The ear will find appropriate discipline in distinguishing, without aid

from the eye, the causes of various sounds, as the opening of a door,

the shutting of a knife, the dropping of various coins, the moving of

different articles of furniture, etc. It may also find appropriate

exercise in determining the direction from which various sounds proceed;

in recognizing acquaintances by their natural voices, and in detecting

the counterfeit voices of companions; in arranging and classifying the

elementary sounds of the language, and in determining all the different

musical tones; in judging of the genus and species of birds by their

chirping, of the distance and nature of sonorous bodies of various

kinds, etc., etc. These are some of the direct means of improving this

sense: others will suggest themselves to the thoughtful reader.

THE SENSE OF SIGHT.--The sense of sight, which is the most refined and

admirable of all the senses, still remains to be considered. The senses

generally serve as interpreters between the material universe without

and the spirit within. But it is more especially by the sense of sight

that we are enabled to hold converse with the external world. Without it

we should be deprived of a large portion of the pleasures of life not

only, but even of the means of maintaining our existence. It is through

the sense of vision that the wisdom, power, and benevolence of the Deity

are chiefly manifested to us.

I shall describe the apparatus of vision only so far as is necessary in

order to subserve my leading object, which is the preservation and

improvement of this sense, and the means of rendering it tributary to

intellectual and moral culture. The eye, which is the organ of vision,

is an optical instrument of the most perfect construction. It is

surrounded by _coats_, which contain refracting mediums, called

_humors_. There are three coats, called the _sclerotic_, the _choroid_,

and the _retina_; and three humors, called the _aqueous_, the

_crystalline_, and the _vitreous_.

The _sclerotic_ or outer coat, called also the white of the eye, is an

opaque, fibrous membrane. It has almost the firmness of leather,

possesses little sensibility, and is rarely exposed to inflammation or

other diseases. It invests the eye on every side except the front, and

besides maintaining its globular form and preserving its internal and

delicate structure, serves for the attachment of those muscles which

move this organ. The opening in the fore part of this opaque coat is

filled by the transparent _cornea_, which resembles a watch crystal in

shape, and is received into a groove in the front part of the sclerotic

coat in the same manner that a watch-glass is received into its case.

But for this arrangement light could not gain admission to the eye.

The _choroid coat_, which constitutes the second investing membrane of

the eye, is of a dark brown color upon its outer surface, and of a deep

black within. The internal surface of this membrane secretes a dark

substance resembling black paint, upon which the retina is spread out,

and which is of great importance in the function of vision, as it seems

to absorb the rays of light immediately after they have struck upon the

sensible surface of the retina.

The _retina_, which is the third and innermost membrane of the eye, is

the expansion of the optic nerve, and constitutes the immediate seat of

vision. Such is the arrangement of the humors of the eye, and so

perfectly are they adapted to the functions they are called upon to

perform, that in the healthy state of this organ, the light entering the

pupil is so refracted as to paint upon the retina an exact image of the

objects from which it proceeds. The optic nerve, whose expansion forms

the retina, receives this image and transmits it to the mind.

Arnott has well remarked, that "a whole printed sheet of a newspaper may

be represented on the retina on less surface than that of a finger nail;

and yet not only shall every word and letter be separately perceivable,

but even any imperfection of a single letter. Or, more wonderful still,

when at night an eye is turned up to the blue vault of heaven, there is

portrayed on the little concave of the retina the boundless concave of

the sky, with every object in its just proportions. There a moon in

beautiful miniature may be sailing among her white-edged clouds, and

surrounded by a thousand twinkling stars, so that to an animalcule

supposed to be within and near the pupil, the retina might appear

another starry firmament with all its glory."

Besides these three coats, and the cornea which constitutes about one

fifth of the anterior portion of the outer coat, it is necessary to

notice the _iris_, so called from its variety of color in different

persons, and upon which alone the color of the eye depends. The iris is

a circular membrane situated just behind the cornea, and is attached to

one of the coats at its circumference. In its center is a small round

hole, called the _pupil_; and sometimes spoken of familiarly as the

sight of the eye, as no light can enter the eye except through it. The

iris possesses the power of dilating and contracting, so as to admit

more or less light, as it may be needed. This change in the size of the

pupil is effected by two sets of muscular fibers. The first set converge

from the circumference of the iris to the circular margin of the pupil,

and constitute the _radiated muscle_. The outer ends of these fibers are

attached to the sclerotic coat, which is unyielding; hence, when they

contract, the pupil _enlarges_ to receive more light. The other set is

composed of circular fibers, which go round in the iris from the border

to the pupil, and constitute the _orbicular muscle_, the contraction of

which _diminishes_ the size of the pupil. When too much light enters the

eye, the excited and sensitive retina immediately gives warning of the

danger, and the nerves, which are plentifully distributed to the iris,

stimulate the orbicular muscle to contract, and the radiated one to

relax, by which the size of the pupil is lessened. But when the light

which enters the pupil is insufficient to transmit a distinct image of

objects to the brain, the orbicular muscle relaxes, and the radiated one

contracts, so as to enlarge the pupil. The contraction of the pupil is

readily seen when a person passes from a darkened room into a bright

sunlight, or when a light is first brought into a room in the twilight

of evening. Any person may notice this contraction in his own eye by

beholding himself in a glass immediately after passing from a dark to a

well-lighted room. So, also, when a person looks at an object near the

eye, the pupil contracts, but when he looks at an object more remote, it

dilates. The muscles of the iris are somewhat under the control of the

will; for most persons can contract or dilate the pupil, in some degree,

at pleasure. Some persons possess this faculty to a great extent.

The three _humors of the eye_ have been compared to the glasses of a

telescope, and the coats to the tube, which keeps them in their places.

The _aqueous_ humor is situated in the fore part of the eye, and is

divided by the iris into what are called the anterior and posterior

chambers of the eye. The _crystalline_ humor, or lens, is situated

immediately behind the aqueous humor, a short distance back of the

pupil, and is a perfectly transparent double convex lens, closely

resembling in shape the common burning glass. This resemblance does not

stop here; for this lens, like the burning glass, possesses the property

of converging the rays of light which fall upon it, and bringing them to

a focus. When this lens becomes so opaque as to obstruct the passage of

light, either partially or entirely, a person is said to have a

_cataract_. This can be cured only by a surgical operation. The

_vitreous_ humor, situated back of the other two, forms the principal

part of the globe of the eye. It differs from the aqueous in one

important particular. When that is discharged in extracting the

crystalline lens for cataract or otherwise, it will be restored again in

a few hours, and the eye will continue to perform its function. But if

this be discharged by accident, the eye is irrecoverably lost. This,

however, does not often occur; for, as we shall presently see, the eye

is admirably fortified.

The eye is a perfect optical instrument, infinitely surpassing all

specimens of human skill. This is true, view it in what light we may. It

not only possesses the power of so adjusting its parts as to adapt it to

the examination of objects at different distances, and in light of

different degrees of intensity, but we are enabled to direct it at will

to objects above, beneath, or around us.

The various motions of the eye are produced by six little muscles. These

are attached at one extremity to the immovable bones of the orbit, while

at the other extremity they are inserted into the sclerotic coat, four

of them near its junction with the cornea, by broad, thin tendons, which

give to the white of the eye its pearly appearance. These muscles are so

arranged by the matchless skill of the Architect as to enable the

beholder to direct the eye to any object he chooses, and to hold it

there for any length of time that is compatible with the laws by which

muscular exercise should be regulated. By the slight or intense action

of four of these, called the straight muscles, the eye is less or more

compressed, and the relative positions of its humors are by this means

so nicely adjusted as to enable us to view objects near by or at a

distance. The other two are called oblique muscles, one of which, with

its long tendon passing through a cartilaginous loop, acts upon the

principle of the fixed pulley, and turns the eye in a direction contrary

to its own action. When the external muscle becomes too short, the eye

turns out; but if the internal muscle is unduly contracted, the eye

turns inward, toward the nose. One eye is sometimes turned up or down,

but this is of less frequent occurrence.

It would be interesting to notice the protecting organs of the eye,

consisting of the _orbit_, which is a deep bony socket, in which the

eye securely rests; of the _eye-brows_, which are two projecting arches,

covered with hair, and so arranged as to prevent the moisture that

accumulates upon the forehead, in free perspiration, from flowing into

the eye; of the _eye-lids_, which are two movable curtains for the

protection of the eye, and which secrete a fluid that moistens and

lubricates it; of the _lachrymal gland_, with its ducts, which keeps the

eye constantly moist, and whose secretions go on while we wake and when

we sleep, etc., etc.; but the preceding must suffice.

With this brief description of the apparatus of vision, we proceed to

the consideration of the means of preserving and improving this sense,

and of rendering it tributary to intellectual and moral culture.

The rule requiring that _action should alternate with rest_, which has

been so often stated, and which applies to all the organs of both body

and mind, should be especially observed in relation to the eye. This

organ requires exercise, and light is its appropriate stimulus; but

injury is the inevitable consequence of keeping it too constantly

employed, or too intently fixed for a long time on any object. Whenever

the eye is fixed for any length of time upon an object which it

distinguishes with difficulty, it experiences a painful sensation, which

is a sure indication that it has been overtaxed. The sight is also

impaired when the eye is too little used, or when its natural stimulus

is shut out, as is strikingly illustrated in the case of persons

confined in dungeons. A distinguished oculist has said that many men

daily impair or destroy their eyes by immoderate use, and that not a few

have done the same by too little use of them.

The exposure of the eyes to _sudden transitions from weak to strong

light_ is very injurious. This may be regarded as one of the must

prolific causes of weakness of sight. The injury is generally gradual,

it is true, but it is none the less fatal on that account. The immediate

sensation of pain, when a strong light is brought into a dark room,

should be a sufficient warning to avoid such sudden extremes. The iris

dilates and contracts, and thus enlarges or diminishes the size of the

pupil as the light that fails upon the eye is faint or strong; but this

dilation and contraction are not instantaneous. There are numerous

instances on record in which total blindness has resulted from a sudden

transition from darkness to the brilliancy of day. The habit of looking

at a bright light of any kind, and especially of watching flashes of

lightning, which is practiced by many, is exceedingly dangerous. The

practice which many students and others indulge in, of resting their

eyes as the twilight of evening advances, and allowing the pupil to

dilate until it is quite dark, and then suddenly introducing a bright

light, is a palpable violation of this rule, and one that is sure,

sooner or later, sensibly to injure the eyes. The exposure of the eyes

suddenly to a strong light upon waking from sleep, and all sudden

changes of whatever kind from darkness to intense light, should be

carefully avoided by persons who would preserve their sight unimpaired.

The strength of light used should be regulated _according to the powers

of the eye_. This is a general, though a very important rule. Both the

amount and the distribution of light should be such as to produce no

unpleasant sensations. The eye possesses a certain degree of adaptation

to light, according as it is intense or feeble. Some eyes require a

stronger light than others, but all eyes are injured by being used in

light that is too intense or too feeble. Reading by a strong sunlight,

and by moon or star light, may be adduced as illustrations which are

alike painful and injurious.

Too little light is well-nigh as injurious as too much, as he can not

fail to have noticed who has had occasion to travel a difficult road in

a dark night. The injury, in such cases, is two-fold; for while, on the

one hand, the radiated muscle of the iris is unduly contracted for a

length of time, in order sufficiently to enlarge the pupil to render

objects visible, the sensitive retina, on the other hand, is overtaxed

to gain a knowledge of them in too feeble light. The pain which the

strained eye thus experiences is only an indication and a warning to the

individual of the permanent injury he is inflicting upon this delicate

organ.

_Rooms should be well and evenly lighted._ The irregular and flickering

light of common lamps and candles is very injurious, and should be

avoided in the study, and in all mechanical pursuits where the eye is

much taxed. The best oculists concur in the opinion that reflected and

concentrated light are highly injurious. Several cases of actual

blindness are recorded as having occurred within a few years from

exposure to concentrated light, and weakness of sight that has unfitted

the individual for usefulness through life has often been thus produced.

The rays of the sun are considered as peculiarly injurious when

reflected from an opposite building or wall, or even when they pass

through a window, and, descending to the floor, are thence reflected to

the eyes. What, then, shall we say of the habit of constructing

school-rooms in such a manner that perhaps a majority of the scholars

are obliged to write and study at desks upon which the direct rays of

the sun shine for a considerable portion of the day unbroken unless it

be by a passing cloud! And yet thousands of school-houses are situated

in such a manner as to create this very necessity all over our country.

At a moderate estimate, the eyes of one hundred thousand children are

taxed in this manner in the schools of the United States every passing

year. A vast amount of discomfort and unhappiness is produced in this

way that might easily be avoided, would parents and teachers take the

trouble. Any exposure of this kind should be immediately obviated,

either by blinds, or by curtains of some soft color. A few newspapers

are much better than nothing. The desks and furniture should be of such

a color that the eye may repose upon them with agreeable sensations.

Nature is clothed with drapery whose color is refreshing to the eye; and

it is false taste, as well as false philosophy, which attempts to dazzle

in order to please it.

_The use of side lights is injurious._ The eye will accommodate itself

to light of different degrees of intensity within a limited range, but

both eyes should be exposed to an equal degree of light. The sympathy

between the eyes is so great, that if the pupil of one eye is dilated by

being kept in the shade, as must, of course, be the case where the light

is on one side, the eye which is exposed can not contract itself

sufficiently for protection, and is almost inevitably injured.

When viewing objects, we should avoid, as far as possible, _all oblique

positions of the eye_. By neglecting this rule, an unnatural and

permanent contraction of the muscle is liable to be produced, as is

illustrated in the numerous instances of strabismus, or cross-eye, which

are every where too common.

_We should accustom the eye to viewing objects at different distances._

The muscles upon which the form of the eye and the size of the pupil

depend are subject to the general laws of muscular action. Their

strength and flexibility, which are increased by healthful exercise, are

impaired by disuse. Hence students who have neglected this rule, and

have accustomed themselves for a long time to view objects near by,

lose the power of adjusting the eye so as to view things at a distance.

As a consequence, they become near-sighted, and put on glasses, when, by

a proper use of the eye, their vision might have been preserved

unimpaired many long years. I know some students upon whom this habit

became so firmly fixed before they were twenty years of age, that they

felt compelled to put on glasses, but who, unwilling to contract so

pernicious a habit in early life, commenced a course of discipline in

accordance with the suggestions here given. By perseverance, their eyes

not only recovered their former healthful action, but became so improved

that they now possess the sense of vision unimpaired not only, but in a

very high state of cultivation.

_Persons become near or long sighted_ as the objects to which they are

accustomed to direct the eye are near or remote. This is illustrated in

the case of students, watch-makers, and engravers, who are accustomed to

examine minute objects near the eye, and, as a consequence, become

near-sighted; and of surveyors, hunters, and sailors, who, being

accustomed to view objects at a distance, become long-sighted. By a

proper discipline of the eye, persons may attain and retain the power of

viewing objects near by and at a distance, as is illustrated in the case

of those gunsmiths who are accustomed to manufacture guns, and to try

them in shooting at a mark at a great distance. The preceding principles

being borne in mind in their various applications. I need, perhaps,

state but one more rule.

He who would secure clear and distinct vision, must observe all those

rules which are necessary to keep the body in health. The sympathy of

the eyes with all the other organs of the body is wonderful and

intimate. There is no other organ whose strength depends so much on the

general vigor of the system. Strict temperance in eating and drinking

may be regarded as an indispensable requisite for the preservation of

healthy eyes. To this may be attributed the clear heads of the ancient

philosophers, who, unlike most students of the present day, exercised

their bodies and limbs as well as their minds. Their works are not the

production of congested brains, for these were not oppressed with blood

belonging to other parts of the body. They studied and thought, and

exercised both body and mind in the open air, and thus observed the laws

of health. But among the multitudes of close students of the present

day, who complain of weakness of the eyes, the misfortune is generally

attributable to an almost total neglect of the first principles of

health.

While we reproach and loathe the man whose eyes are red and weeping with

the effects of intemperate drinking, we cordially pity purblind

students, as in some sense martyrs to the cause of learning. Dr.

Reynolds, a distinguished American oculist, administers a rebuke to such

which we fear is too often merited: "A closer examination of their

history presents a very different result. Our sympathy may grow cool if

we regard them with a physiologic eye. It is a love of the flesh, more

than a love of the spirit, that too often clouds their vision. It is too

much food, crowding with unnecessary blood the tender vessels of the

retina. It is too little exercise, allowing these accumulated fluids to

settle down into fatal congestion. It is positions wholly at variance

with the freedom of the circulation, and various other imprudences,

which are the results of carelessness or unjustifiable ignorance. 'The

day laborer may eat what he will, provided it is wholesome, and his eyes

will not suffer. But let the student, who is called upon to devote not

only his eyes, but his brain, to severe labor, live upon highly

nutritious food, and such as is difficult of digestion, and we shall

soon see how his vision will be impaired, through the vehement and

persevering determination of blood to the head, which such a course must

inevitably occasion.' So speaks Beer, whose extensive opportunities of

observation have perhaps never been exceeded. The daily practice of

every observing oculist is filled with coincident experience."

Among the prevalent habits of students by which the eyes are injured,

the same writer mentions the irritation produced by rubbing them on

awaking in the morning, a practice which has in some cases occasioned

permanent and incurable disease; reading while the body is in a

recumbent position; using the eyes too early after the system has been

affected with serious disease; exercising them too much in the

examination of minute objects; the popular plan of _using green

spectacles_, and _the use of tobacco_.

Light which is sufficient for distinct vision, and which falls over the

shoulder in an oblique direction, from above, upon the book or study

table, is generally regarded, and with great propriety, as best suited

to the eyes. Some oculists prefer to have the light fall over the _left_

shoulder.

The acuteness of this sense and the extent of its cultivation are very

much greater in some individuals and classes of men than in others. This

is a fact that has been remarked by observing persons. Its consequences

should not be overlooked, for they are neither few nor unimportant.

Those persons who have been long accustomed, either by the necessity of

their situation, the example of those about them, or the judicious care

of parents and teachers, to observe attentively the relations of parts,

the symmetry of forms, or the shades of color, have eyes that are

perpetually soliciting their minds to notice some beautiful or grand

perceptions. Wherever they turn, they espy some new, and, therefore,

curious arrangement of the elements of shape, some striking combination

of light and shade, or some delicious peculiarity of coloring. The

multiplicity and variety of their perceptions must and do increase the

number of their thoughts, or give to their thoughts greater compass and

definiteness. Such persons are likely to become poets, or painters, or

sculptors, or architects. At any rate, they will appreciate and enjoy

the productions of others who have devoted themselves to these

delightful arts. And will not such persons be most readily awakened to

descry and adore the power, the skill, and the beneficence of the Great

Architect who reared the stupendous fabric of the universe, who devised

the infinite variety of forms which diversify creation, and whose pencil

has so profusely decked every work with myriads of mingling dyes,

resulting all from a few parent colors? To an unpracticed eye, the

beauties and wonders of creation are all lost. The surface of the earth

is a blank, or, at best, but a confused and misty page. Such an eye

passes over this scene of things, and makes no communication to the mind

that will awaken thought, much less enkindle the spirit of devout

adoration, and fill the soul with love to Him "whose universal love

smiles every where."

Mr. May speaks no less sensibly than eloquently when he says, "I may be

extravagant in my estimation of the importance of the culture of the eye

and the ear, but so it is, that while I have been reading the writings

of the Hebrew Prophets, and of those other gifted bards who communed so

intently with nature and with nature's God, it has seemed to me

impossible that any one could enter fully into all the tenderness,

beauty, and sublimity of their language, or receive into his heart all

its peculiarity of meaning, unless his own eye had been used to trace

the skill of that hand which framed and fashioned every thing that is,

and to descry the delicacy of that pencil which has painted all the

flowers of the field, nor unless his own ear has learned to perceive the

melody and harmony of sounds."

We can discipline the sight directly, and to a very great extent; and we

can have the satisfaction of perceiving the progressive improvement of

the faculty. For this purpose, every school should be furnished with

appropriate apparatus. A set of measures is indispensable. I will

illustrate by an example. For the benefit of the primary department

connected with a seminary of learning that was formerly for several

years under my supervision, I constructed a set of rules for linear

measurement. Their breadth and thickness were uniform, each being an

inch wide and half an inch thick. The set consisted of nine rules, whose

lengths were as follows: four were each one foot long; one, a foot and a

half long; two, two feet; one, two and a half feet; and one, three feet.

Every rule had a small hole bored through each end. I had also a number

of small pins turned just the right size to fit these holes. I have

since submitted to several hundred teachers, in institutes and

elsewhere, my mode of combining and using these measures; and from the

deep interest which a large number of intelligent parents and teachers

in different localities have manifested in the subject, I venture to

refer to it in this connection. I first tried the experiment ten years

ago, with a class of about twenty children from four to seven years of

age. Several of these could not read, and some of them had not learned

the alphabet. The children were first led to observe carefully the

length of these several rules, until they could determine at sight the

length of each. For several of the first lessons some of them would

misjudge. They would, for instance, call a two foot rule one and a half

or two and a half feet long. In such cases their judgments were

immediately corrected by the application of two one foot rules. They

were then led to observe with care, tables, desks, etc., and to estimate

their length, and were afterward permitted to measure them, and discover

the degree of accuracy in their decisions. After obtaining the opinions

of the children in relation to the length or height of an object, I

would measure it myself in the presence of the class. When the class

became a little experienced, we examined the length, breadth, and height

of rooms, of houses, and of churches; and then the distance of objects

less or more remote, correcting or confirming their estimates by the

application of the rule or measure, which gave a permanent interest to

the exercise. By exercising the class in this manner, not to exceed half

an hour a day, they would, at the end of the first quarter, judge of

each other's height, of the height of persons generally, of the length

of various objects, of the size of buildings, and of the dimensions of

yards, gardens, and fields, with greater accuracy than the average of

adult persons, as was tested by actual measurement in some instances

where there was a disagreement in opinion.

By holding these rules in different positions, the children readily

became familiar with the meaning and practical application of the terms

perpendicular, horizontal, and oblique. They would also tell which term

is applicable to the different parts of the stove-pipe; to the different

parts of the furniture of the school-room; to the floor, sides of the

room, roof, etc.; and to all objects with which they were familiar.

But the reader may inquire, what is the use of the holes and the pins?

By pinning two rules together, one resting upon the other, and then

turning one of them around, the class will readily gain a correct idea

of the use of the term _angle_; also of the terms acute angle, right

angle, and obtuse angle. By pinning three of these rules together at

their ends, the children not only _see_, but can _handle_ the simplest

form of geometrical figures. When this figure is _defined_, they are

enabled permanently to possess themselves of the meaning of the word

_triangle_, by the simultaneous exercise of _three senses_. By combining

rules of the same and different lengths, they become familiar with

equilateral, isosceles, scalene, right, and obtuse angled triangles. By

combining, in this way, such a set of rules as I have described, the

child readily becomes familiar with the names and many of the properties

of more than half a score of geometrical figures, with less effort on

the part of the teacher than would be required to teach the child the

names of the same number of letters. These exercises, then, may well

precede the learning of the alphabet, or, at least, proceed

simultaneously with it. By this means the child's interest in the school

is increased; his senses are cultivated; he is enabled better to fix his

attention; he progresses more rapidly and thoroughly in his juvenile

studies, and at the same time lays the foundation for future excellence

in penmanship and drawing, and other useful arts.

The child may also be taught to discriminate the varieties of green in

leaves and other things; of yellow, red, and blue, in flowers and

paints; and to distinguish not only the shades of all the colors, but

their respective proportions in mixtures of two or more. Many persons,

for want of such early culture, have grown to years without the ability

of distinguishing between colors, as others have who have neglected the

culture of the ear without the ability of distinguishing between tunes.

Drawing, whether of maps, the shape of objects, or of landscapes, is

admirably adapted to discipline the sight. Children should be encouraged

carefully to survey and accurately to describe the prominent points of a

landscape, both in nature and in picture. Let them point out the

elevations and depressions; the mowing, the pasture, the wood, and the

tillage land; the trees, the houses, and the streams. Listen to their

accounts of their plays, walks, and journeys, and of any events of which

they have been witnesses. In these and all other exercises of the sight,

children should be encouraged to be strictly accurate; and whenever it

is practicable, the judgment they pronounce and the descriptions they

give should, if erroneous, be corrected by the truth. Children can not

fail to be interested in such exercises; and even where they have been

careless and inaccurate observers, they will soon become more watchful

and exact.

It is by the benign influences of education only that the senses can be

improved. And still their culture has been entirely neglected by perhaps

the majority of parents and teachers, who in other respects have

manifested a commendable degree of interest in this subject. That by

judicious culture the senses may be educated to activity and accuracy,

and be made to send larger and purer streams of knowledge to the soul,

has been unanswerably proved by an accumulation of unquestionable

testimony. Most persons, however, allow the senses to remain uneducated,

except as they may be cultivated by fortuitous circumstances. Eyes have

they, but they see not; ears have they, but they hear not; neither do

they understand. It is not impossible, nor perhaps improbable, that he

who has these two senses properly cultivated will derive more unalloyed

pleasure in spending a brief hour in gazing upon a beautiful landscape,

in examining for the same length of time a simple flower, or in

listening to the sweet melody of the linnet as it warbles its song of

praise, than those who have neglected the cultivation of the senses

experience during their whole lives!

This subject commends itself to all who regard their individual

happiness, or who desire to render their usefulness as extensive as

possible. Upon parents, teachers, and clergymen, who are more

immediately concerned in the correct education of the rising generation,

its claims are imperative. Let them be met, in connection with other

appropriate means now in use and hereafter to be put in requisition, and

our schools can not fail to become increasingly attractive; truancy,

hence, will be less frequent, and the benign influences resulting from

the correct education of the _whole man_ will inspire the benevolent and

philanthropic to renewed and increased efforts to secure the right

education of _all men_, a condition upon which the maximum of human

happiness depends.