THE SENSES, AS THE INLETS TO KNOWLEDGE--SIGHT AND HEARING.
1. _Sight._--The information acquired by the mind through the sense of
sight is more varied than that communicated through any other sense,
singly taken; but it is less accurate. The sense of sight requires
education and assistance, and both are given through the sense of
touch. We have already said, that light radiates from bodies, and
forms a picture on the retina, (a reversed picture,) conveying to the
mind certain qualities of matter, and, first--colour. By variations in
the shades of colour, and by contrasts of colour, our eye, aided by
experience from the sense of touch, determines the form of objects; and
the boundaries of these forms we term outlines. All that we perceive
is the limits of differently coloured spaces. Where, however, colours
blend gradually into each other, the limits of each space, and,
consequently, its outline, are indefinite; we do not see matter, but
a quality of matter. There are circumstances under which the eye is
deceived respecting colour, two or more different colours producing
a similar effect on the retina, and being undistinguishable from each
other. Moreover, when the retina is fatigued by a prolonged impression
from one colour, its sensibility to colour is diminished, and we cease
to judge accurately; in these instances, the retina receives those only
which are termed _accidental_, namely, which do not enter into the
colour steadily gazed at previously. For example, "if we look steadily
at a white spot, and afterwards turn the eye towards white bodies, a
dark spot will be perceived by the eye. If we look at a red spot on
a white ground, and then direct the eye to another part of the white
ground, a green spot approaching to blue will be perceived. In the
first case, the retina was fatigued by the white colour, and could not
be excited by any other colour having the rays which constituted it in
its composition. The _accidental_ colour, therefore, was black. In like
manner, after looking at the red spot, the retina was insensible to the
impressions of a compound colour, having red rays in its composition.
Hence, the accidental colour consisted of the other rays of the
prismatic spectrum, forming a colour destitute of red."
The eye is subject to deception, or illusion. Sometimes we mistake the
shadow for the substance. The rays of light, passing through media
of different densities, are refracted at different angles; hence the
direction or nearness of different bodies becomes apparently altered,
and experience alone corrects the error. On putting a pole or stick
obliquely into clear water, the submerged portion seems to be bent
at the surface of the water, and to rise higher in the water than it
actually is. The bottom of a deep, clear river, or pond, seems to be
nearer to the surface than it is in reality; in other instances, the
water deceives by an apparent shallowness, the truth of which the
inexperienced bather should always test before venturing in. If a gold
or silver coin be put at the bottom of a basin, and the basin be then
filled with water, and the eye be obliquely directed, so as not to
see the coin, hidden by the rim of the basin, it will become apparent
when the basin is filled. In spearing fish, allowance is made by the
experienced for the difference of refraction of the rays of light in a
rare and more dense medium. It is probable that birds which prey upon
fish, by darting at them while at a certain distance under the water,
as, for example, the fish-hawk, or osprey, and the gannet, are taught
by _instinct_ to correct an apparent error of sense, or rather, an
illusion, which man corrects by practice and experience.
The eye is deluded by the mirage. The mirage (a French word, adopted
into our language) is "the name given to a phenomenon of unusual
attraction, for which we have no specific appellative, unless it be the
sea-term _looming_. As a general definition, we may say, the mirage is
an optical illusion, occasioned by the refraction of light through
contiguous masses of air of different density, such refraction not
unfrequently producing the same sensible effect as direct reflection.
"The illusions of the mirage differ according to circumstances, but
they may be all arranged under one or other of the three following
classes: _vertical reflection_, _horizontal_ or _lateral reflection_,
and _suspension_."
In hot, flat regions, as certain portions of Arabia, Egypt, Persia,
the western deserts of India, etc., the _vertical mirage_ is extremely
common; it presents the illusive appearance of a wide, clear lake, or
sheet of water, in which trees, buildings, and other objects, seem to
be reflected, and in a reversed position. On approaching this deceptive
lake, it keeps receding as we advance, the reflected images vanish,
to be succeeded by others, as they come in rotation into sight. And
thus the wayworn and thirsty traveller across the desert is first
cheated into hope, and at length mocked into despair. During the
French campaign in Egypt, under Napoleon, the soldiers, who suffered
extremely from the torments of thirst, were cruelly tantalized by the
deceptive mirage. M. Monge, one of the savans who accompanied the army,
thus comments upon this phenomenon: "The soil of Lower Egypt," he
observes, "is a vast plain, perfectly horizontal, its uniformity being
interrupted by a few eminences, on which, in order to secure them from
the inundations of the Nile, the villages are built. In the morning
and the evening the aspect of the country presents nothing remarkable,
all objects appearing in their natural positions, and at their proper
distances; but after the soil has become heated by the rays of the
sun, the prospect seems bounded by a general inundation. The villages
at a little distance appear as islands in the midst of an expansive
lake, and the image of each village is seen invertedly reflected, as
if the water were real. As we advance, the mimic water retires, still
reflecting image after image;" so that in this illusion the classic
fable of Tantalus is represented; might not the fable have had its
origin in the phenomenon of the mirage?
It is not, however, exclusively on sandy plains or in very hot
climates, that this mirage occurs. It has been observed by Biot over
the sandy beach of Dunkirk, and is not unfrequent along the coast of
Calvados. A strange and beautiful effect of the mirage was seen by
captain Maundy, at the Shallout Pass in India, and is thus described:
"A deep precipitous valley, at the bottom of which I had seen one or
two miserable villages in the morning, bore in the evening a complete
resemblance to a beautiful lake. The vapour which played the part of
water, ascended nearly half-way up the sides of the vale, and on its
bright surface the trees and rocks were distinctly reflected."
How like the vanities and pleasures of earth is the mirage! Bright,
sparkling, illusive--an appearance without a substance--a mockery
which deceives, attracts, and vanishes away! He who pursues the
pleasures of this world, and all its tinsel gratifications, resembles
the fevered traveller in the burning desert, who pursues the mirage,
which recedes as he presses eagerly towards it, till at length,
discovering its nothingness, he perishes.
We may next consider the mirage produced by _horizontal_ or _lateral
reflection_.
"In the horizontal or lateral reflections, the mirage represents the
reflected image sideways. Thus, on the 17th of September, 1818, M.
Jurine and Soret observed a lateral mirage on the lake of Geneva. A
bark, about four thousand toises distant, was seen approaching Geneva
by the left bank of the lake, and at the same moment there was seen
above the water an image of the sails, which, in place of following the
direction of the bark, receded from it, and seemed to approach Geneva
by the right bank of the lake, the image sailing from east to west,
while the bark was sailing from north to south. This lateral mirage
is known to the inhabitants of Meroa, who call it _Si-koté_, (castle
of the cold season;) by those who live on the plains watered by the
Chumbul and the Jumna, it is termed _Dissaser_, (prognostic.)
"In particular situations, both the _vertical_ and _lateral_ mirage
may be observed together. Thus the late Mr. Blackadder has described
some phenomena, both of vertical and lateral mirage, as seen at king
George's Bastion, Leith, which are very instructive.
"The phenomenon called _suspension_, which is the third kind of
mirage, and to which the term _looming_ is most strictly applied, is
the picturing of an object immediately over it in the air, frequently
without reversion of the image. Sometimes the objects are merely raised
above the height at which, under ordinary circumstances, they would
appear. Thus sir R. K. Porter mentions a phenomenon of suspension, or
_looming_, in the plains near Bagdad. 'A little before morning,' says
he, 'I observed an elevated stream of water, which, from its situation,
must be the Tigris. Its surface was brilliantly illuminated by the
moon, but the longer I kept my eye fixed on this noble river of many
interests, the more my surprise became excited at the extraordinary
height of its waters above the level of the desert, till at length
I began to suspect that some optical illusion from refraction was
assisting the apparent elevation of the stream; but I had not conceived
the extent of the deception, for as the dawn advanced the phantom
river totally sunk from my sight.' The phenomenon of _looming_ is most
generally observed at sea, or near the shore. At Reggio, in Calabria,
the _Fata Morgana_ (Fairy Morgana) is visible, which for many centuries
astonished the vulgar and perplexed philosophers.
"It frequently happens that the phenomenon of the _vertical_ mirage is
combined with that of _suspension_, so as to show in the air both a
direct and an inverted image of the subject, the latter being undermost.
"Now all these phenomena, and their various modifications, depend on
the different density of the lower strata of the air; and as this
difference of density may be occasioned both by heat and moisture,
and as heat may be reverberated from the mountain's side as well as
from the horizontal surface of the plains, from the sea as from the
land--and, further, as contiguous columns of air, as well as horizontal
strata, may be of different densities, it is easy to conceive why
the mirage may be seen in very different situations, as also why it
presents such varied appearances. It will also be evident that any
cause which re-establishes the equilibrium of density in the different
portions of the air, must cause the illusions of the mirage to
vanish."[11]
[11] Penny Cyclopædia.
It cannot be doubted that those appearances, which sailors call _Cape
Fly-away_, the _Enchanted Island_, and the _Flying Dutchman_, etc., are
the effects of the mirage. They are the objects of superstition, and
thus has an illusive appearance caused many a heart to beat with fear,
which never so beat in the tempest or the sea-fight.
The eye assists us greatly, indeed almost exclusively, in determining
the _motions_ of bodies; yet in this we require experience, and after
all we are frequently deceived. When a body moves in a straight line
from us, we cannot tell whether it moves or not, and then only come
to the conclusion that it recedes in consequence of its becoming more
obscure, and from a change in its relative position to other objects
which we know to be stationary. When we travel in a railway carriage,
the banks, the hedge-rows, and the fields, seem as if gliding with
extreme velocity away from us. It is only by a course of reasoning that
we know such is not the fact; it is true that the course of reasoning
is very short and simple, yet still that reasoning is requisite;
indeed, it has been acknowledged only in modern times that the sun
is stationary, and that the world moves. Bodies moving with extreme
velocity produce a continuous impression on the eye; thus, for example,
if a stick burning at one end be rapidly whirled, the burning end
produces the appearance of a fiery circle. The spokes of a coach-wheel,
rolling round very rapidly, present the appearance of an indistinct
expansion. On the contrary, bodies moving with extreme slowness appear
to casual observation as stationary; thus the act of growing, in
ordinary plants and animals, is not appreciated, though the result is
demonstrated in due time.
The eye, moreover, may be deceived by artificial representations, as
by painting (take the Diorama as an example) or by models. We have
seen flowers so truthfully modelled in wax that, by the eye alone, no
distinction between them and natural flowers could have been detected.
The same observations apply to _magnitude_ and _distance_. Objects of
gigantic magnitude, as, for instance, the pyramids of Egypt, at first
appear less than they are in reality; and it is only by admeasurement,
examination, and comparison, that the mind becomes impressed with
the idea of their immensity. A building, the details of which are
in just harmony, always appears to be smaller than it is, because
no discordance betrays the vast preponderance of certain parts over
the littleness of others. Habit, or, in other words, education, is
essentially requisite to aid the eye in its appreciation of magnitude.
We may say the same with respect to _distance_. An infant does not
distinguish between near and distant objects; its eyes have yet to
become educated, and so have those of adults placed in circumstances to
which they are unaccustomed. For example, the walls of a city, reared
in a vast level plain, and descried at a distance, appear to be far
nearer than the traveller will find them to be; again, when standing on
the beach, we look at a ship in the distance, we are apt to think it
closer to the shore than we should prove it to be were we to traverse
the distance in a boat. A sailor would judge of the distance accurately.
How much the accuracy and utility of the eye depend upon practice or
education may be illustrated by the case of a boy, who, as described by
Cheselden, was born quite blind, but was suddenly restored to sight, at
the age of twelve, by the skilful removal of the cataract. At first,
he was impressed with the idea that all the objects which he saw around
him touched his eyes, in the same manner as in the act of touch they
came in contact with the skin. He could neither estimate distance, nor
distinguish one object from another, until he had applied the test of
touch as a corrective and assistant.
It may here be asked, how the fact is to be explained that, though
images are pictured on the retina inverted, we do not see them as such,
but in their true position? When we say that the eye sees, we use
popular, but not strictly correct language; the eyes are the organs
or instruments of vision--that is, for transmitting certain qualities
of matter to the mind; it is not the image on the retina which the
mind contemplates, for we are utterly unconscious that such an image
exists--it is the object itself. "To expect that the impression from an
inverted image on the retina should produce the perception of a similar
position in the object viewed, is to commit the error of mistaking
these images for the real objects of perception, whereas they are only
the means which suggest the true perceptions. It is not the eye which
sees; it is the mind." "The analogy which the optical part of the eye
bears to a camera obscura has perhaps contributed to the fallacy in
question; for in using that instrument we really contemplate the image
which is received on the paper, and reflected from it to our eyes; but
in our own vision nothing of this kind takes place."
We scarcely know whether we can place among optical illusions those
strange apparitions of departed persons, of friends at a distance,
or of singular and grotesque faces or figures, of which we have many
authentic narratives. These we take to be strong impressions on the
mind alone, (for no image can there be on the retina,) the result of
some morbid condition of the brain and nervous system. Such was the
evil genius which Brutus saw in his tent before the battle of Philippi,
and such the air-drawn dagger of Macbeth--such also were the phantoms
seen by Nicolai, the philosophic bookseller of Berlin, who has given
an admirable account of his mental visions, referring them to their
true source, at the very time that the illusions visited him. In some
states of body, we see grotesque and ludicrous objects, while our eyes
are shut, and, as we can testify, often not before we have shut our
eyes, and thereby closed the door of access through those organs to the
mind. What horrible phantasms terrify the unhappy sleeper labouring
under night-mare! What strange things does the delirious sufferer
mentally behold, and through what strange scenes, real to him, does he
pass! We see, we converse, we laugh, we mourn, we feel pleasure and
anguish, even in our dreams. These, then, are not optical but mental
illusions--no figure is made upon the retina appealing to the mind,
but the mind itself sees things which are not, and is delighted or
terrified by its own involuntary creations.[12]
[12] See "An Essay towards a Theory of Apparitions," by
John Ferriar, M.D., 1813; and "Sketches of the Philosophy
of Apparitions; or, An Attempt to trace such Illusions to
their Physical Causes," by Samuel Hibbert, M.D., 1824.
In former times, craft, under the name of religion, availed herself of
these mental illusions, and extorted gifts of lands and gold from the
terrified, perhaps most guilty sufferer, in order that his peace with
the church (so miscalled) might be made, and masses said for the repose
of his soul. He was taught to buy his entrance into heaven--not with
the Pearl of great price--not by presenting before the Judge of all
mankind the merits and the atonement of the Messiah, but by founding
a monastery, or by adding to its treasures and domains. His faith was
placed, not on the promises of God in Christ, but on the promises of a
mere mortal at best--yes, a mortal, who knew that while he promised he
was weak as other men; In concluding our observations upon the sense of
sight, we may refer to a few striking passages in Scripture, of great
force, and well calculated to excite reflection. "He that formed the
eye, shall he not see?"[13] No secrets are hidden from God; no, not the
secrets of the heart, for these are written on a tablet which he, and
he alone, can read. May our prayer be, "Let the meditation of my heart
be acceptable in thy sight, O Lord, my strength, and my Redeemer!"[14]
"Enter not into judgment with thy servant: for in thy sight shall
no man living be justified."[15] In the sight of God, we speak
figuratively, all men are sinners, and as sinners condemned; but God
will not enter into judgment with those who, by faith in the atonement,
looking to the Saviour, as the Israelites looked to the brazen serpent
in the wilderness, turn away from their wickedness, and become examples
"of the believers, in word, in conversation, in faith, in purity."
[13] Psa. xciv. 9.
[14] Psa. xix. 14.
[15] Psa. cxliii. 2.
2. _Hearing._--What we call sound, noise, or tone, is a mental
appreciation of the effects of the tremulous or vibratory motions
of the particles of an elastic fluid, such as air or water, on the
auditory or acoustic nerves of the internal ear. Sonorous vibrations
are produced by the concussion of hard bodies, by the bolt of
lightning, by the vibrations of stringed instruments of music, by the
forcible current of air thrown into the tubes of wind instruments,
and by the air driven from the lungs through the organs of voice in
reptiles, birds, and mammalia. There are, indeed, few movements, few
collisions, few atmospheric disturbances, which do not excite those
tremulous wavelets of atmosphere, those oscillations, which produce
in us the sensation of sound. In fact, during the day, the sense of
hearing is as perpetually employed as is that of sight; yet, strange to
say, from the impressions made through the medium of both these senses,
we can so far abstract the mind, and throw it upon its own internal
reflections and operations, as to see without discrimination, and to
hear without attention or notice.
As sound is the result of the tremulous fluctuations of air, it will
not surprise our reader to know, that no sound is conveyed from
the percussion of bodies in a vacuum. The experiment of suspending
a bell in the exhausted receiver of the air-pump, and causing the
clapper to strike it as when rung, has been very often repeated; no
sound is communicated to the listener, although the vibrations of
the bell are clearly perceived; should a little air be now admitted,
a faint tinkling is heard, which becomes stronger in proportion to
the admission of air, until it is natural; on the contrary, if the
receiver be filled with greatly condensed air, the tinkling of the bell
is louder than it is when in an atmosphere of the ordinary degree of
density.
Sound, or, rather, the wavelets of the atmosphere producing this
sensation, radiate from the sound-causing object in all directions;
these wavelets, however, extend only to a certain distance, according
to the violence of the central agitation; they become gradually feebler
and feebler, and at last die away. Thunder, the firing of cannon,
and the clang of trumpets, are not heard beyond a certain distance,
and even at that distance, whatever it may be, the ear only faintly
distinguishes the report, for the vibratory action and reaction on each
other of the atmospheric particles, become feebler and feebler in
proportion to the aërial distance of the listener.
If we stand on an eminence commanding a view of a number of cannon,
say a mile distant, which the soldiery are from time to time firing,
a decided difference of time will be perceived between the flash and
the report; the same observation applies to lightning, a considerable
interval often occurring between the flash and the thunder. Hence,
light is said to travel faster than sound. Sound travels at the ratio
of about twelve miles and a half in a minute, but its velocity is
greater in a denser than in a rarer medium, as is also the distance to
which it is propagated. These points are illustrated by a comparison
of water with atmospheric air. All aquatic animals are not constituted
for hearing; myriads, indeed, have neither sight nor hearing. By the
cuttle-fishes (_cephalopoda_) both these senses are enjoyed as well
as by fishes, aquatic reptiles, and we need not say by such aquatic
mammalia as whales, grampuses, porpoises, etc. To them the water is
the medium of sound, and granting that their auditory nerves have the
same sensibility as those of man, they will hear sounds not only more
quickly, more distinctly, but at greater distances. This is accounted
for by "the greater elasticity of the constituent particles of water,
within the minute distance required for their action in propagating
sound. Stones struck together under water are heard at great distances
by a person under water. Franklin found, by experiment, that sound,
after travelling above a mile through the water, loses but little of
its intensity. According to Chladini, the velocity of water is about
four thousand nine hundred feet in a second, or between four and five
times as great as it is in air."
Different bodies conduct sound to the ear with more or less
distinctness, according to their susceptibility for vibrating, and
also with more or less rapidity. Ice, for example, conveys sound
more speedily than water, and far more rapidly than air; thus, if a
cannon on the edge of a frozen lake be fired, a person on the opposite
side will find the flash to be followed by two reports, the first
conducted to him by the ice, the second by the air. If a long steel
rod be applied to the orifice of the ear, the gentlest jar given to
its further extremity, and which, but for the intervention of the
metal, would not have been audible, produces a strong and distinct
impression. Cotton wool, sheeps' wool, and soft stuffs, generally are
bad conductors of sound. The frozen earth conducts sound from great
distances; the approach of a horseman in clear, frosty weather, will be
heard at a far greater distance than when the ground is moist, or not
hardened; in the former case, indeed, a double sound may sometimes be
heard, one produced by the vibration of the ice-bound earth, the other,
if distance allow, by that of the air.
The distance to which sound can be conveyed through the
speaking-trumpet is very surprising. The invention of the modern
speaking-trumpet is generally accorded to sir Samuel Moreland, (1670,)
and some of the large brass trumpets, made under his direction, carried
the human voice from a mile and a half to between two and three miles
distance. The efficiency of this instrument has been attributed to
the repeated reflection of the sound, or waves of air, (like rays of
light,) from side to side along the course of the tube, their ultimate
efflux from the mouth of the instrument being in such a way, as either
to cause the rays of sound to be collected into a focus at a distance,
or to be projected forward in parallel lines, instead of allowing
them to diverge in all directions, and on these principles various
modifications in the form of the speaking-trumpet have been suggested.
The views, however, of professor Leslie do not coincide with this
theory. "The performance of the speaking-trumpet," he says, "does
certainly not depend upon any supposed repercussion of sound; repeated
echoes might divide, but could not augment the quantity of impulse."
His idea is, that "the tube, by its length and narrowness, detains
the efflux of air, and has the same effect as if it diminished the
volubility of that fluid, or increased its density." "The organs
of articulation," he adds, "strike with concentrated force; and
the pulses thus so vigorously excited are, from the reflected form
of the aperture, finally enabled to escape and spread themselves
along the atmosphere." The experiments of Hassenfratz, a French
philosopher, are cited in support of this theory. He tried the power
of a speaking-trumpet, by measuring the distance at which the ticking
of a watch could be heard through it, and found the effect the same,
whether the metal tube were used simply, or wrapped round in such a way
as to prevent vibration. It was also heard at the same distance when
the inner surface was lined with linen, or woollen cloth, to diminish
reflection; and the range of a cylindrical trumpet was the same as that
of a conical one.
In the ear-trumpet, used by persons partially deaf, and in the
stethoscope, it appears to us that we have concentrations of sound into
a focus, by repeated reflexions of the aërial wavelets from side to
side of the tube; and we may ask, does not the murmuring sound which we
hear, when we apply a conch shell to our ear, arise from the same kind
of percussion?
In echoes we have an instance of the reflection of atmospheric
undulations, and this reflection, as in many natural situations, may
be multiplied till the last faint repetitions die away; and when
a succession of echoes is very rapid, a loud exclamation of the
monosyllable, Hah! may be thrown back upon the ear like a boisterous
laugh. The echoes of old halls and galleries, of vaults and dungeons,
of caverns, rocks, and grottoes, have served as subject-matter for
the writers of imaginative poetry and romance. It is not only to old
romantic halls and galleries that echoes are confined; they are not
uncommon in modern public buildings, so that the speaker hears his
words repeated. "The distribution of sound in public edifices, so that
the echoes (or reflections of aërial waves from the walls, etc.) may
be most advantageously brought to strengthen the original sound, is
a subject deserving of much attention." For some observations on the
errors of architects on this point we may refer to sir J. Herschel's
Treatise on Sound.
When our auditory nerves receive a succession of uniform impulses at
equal intervals of time, the intervals being at the same time very
small, the impressions become so interblended with each other as to
produce an apparently continuous sound, even and equal, except as to
variation in loudness. This sound we call a musical note, produced
by the string of the violin, or piano; if the intervals between the
vibrations be, comparatively speaking, long, the note is grave; but if
within the same given time the vibrations be very numerous, the note
is in proportion acute. Some notes harmonize with each, and thereby
please the mind through the ear; others are discords, and offend. Grave
or acute notes depend upon the length and the tension of the strings
of an instrument, or the length of a wind instrument. In the piano,
the low notes are produced by long, thick strings, the high notes by
slender, short wires, in which the vibrations are excessively rapid.
In the violin, which has strings of equal length, the thin strings for
producing the high tones are screwed to a far greater degree of tension
than those of the lower tones; and each string, as its length (that is,
vibratory length) is shortened by the pressure of the finger at due
intervals, produces high and higher tones in proportion.
We have here said enough (for we aim not at a treatise on acoustics)
to show what sound really is, and what are the principal laws by which
it is governed. We have also shown, that it is our mind alone that
takes cognizance of the impulses given by vibratory wavelets of the
atmosphere to the auditory nerves; consequently, that as the mind sees,
so the mind alone hears, for vibration cannot in and of itself be that
sensation which we call sound.
What is the knowledge gained through the ear by the appreciation of
sound, or in common language, by hearing? Let us answer:--We commonly
judge of the distance and position of objects producing sound by the
sense of hearing, but in these points our accuracy greatly depends
upon our attention and our experience. Yet are we liable to deception;
we are thoroughly deceived by a skilful ventriloquist, who can so
modulate his voice as to make it seem distant or near, or to proceed
from one quarter of the room or house, or from another. The voice of
the corn-crake (_Crax pratensis_) is, from some cause or other, very
perplexing; sometimes it will appear as if the bird were only a few
yards distant from us, and the next instant in some far part of the
field. Perhaps instinct leads it to alter the pitch of its monotonous
cry, in order to deceive the intruder. Again, echoes deceive the ear;
not only may we mistake echo for the actual voice of the speaker, but
it may appear as if close or distant, faint or loud, and thus in every
point lead to erroneous conclusions.
That the ordinary animals around hear will not be denied, nor can we
blind ourselves as to the fact, that they acquire a limited share of
information, bearing upon their corporeal necessities, through this
sense. Animals have a natural language, expressive of pain or pleasure,
of surprise, of fear, of anger; and this language consists of cries or
tones, variously modulated, each species having its own range of vocal
intonations. Every species understands the simple instinctive language
of its own species. Some birds, for example, as the wild geese, have
sentinels around the flock while feeding, and rise _en masse_ at the
warning cry of their guards. Who has not marked the distress and
agitation of the ewe, when she hears the plaintive tremulous bleat of
her lamb, forcibly separated from her? The warning note of the cock,
his cluck of invitation, his scream of surprise or fear, his cackle
of agitation, his crow of defiance, are well understood by his train.
Quadrupeds, birds, and even some insects call to each other, and are
answered again--
"Steed answers steed with loud and boastful neighing."
The bird invites his mate by a sweet strain, and is answered by her
low chirp. The call of the young in their nests is responded to by the
parents; the parents call to each other, as if to assure themselves of
each other's safety, or to find out where they mutually are, and what
they are doing.
Imitation is an instinct; we see it powerful in its dominion over
children; it is in exercise before reason assumes a definite sway; it
prompts to the acquisition of the mother-tongue, till, by repetition,
the true pronunciation is acquired, and the names of all common
articles known: then reason steps in. But imitation is not confined
to the human race; monkeys imitate, and the grotesqueness of their
imitations renders them ludicrous; they do not imitate voice, but
action. Some birds, however, imitate the human voice, and are easily
taught to utter words or sentences, (the parrot, the mino-bird, the
magpie, are examples,) nay, even to sing musical airs with great
accuracy. But, by all this acquisition through the organ of hearing,
they gain no information, nor add to the limited number of their ideas.
The parrot may be, indeed, made by practice to associate the sound of a
word, say bread, with the article thus denominated, and to call for it
by name when wanted; but reason steps not in to give further assistance
in the building up of idea upon idea, without which there can be no
definite language--no real speech. Though the dog and the horse cannot
utter the sound, they know what bread is quite as well as the parrot,
and, indeed, the ear of the dog is the inlet to an instinctive mind of
no mean order, for the Almighty created the dog to be man's assistant
and humble friend.
The question has been often mooted, as to whether song-birds acquire
their respective warble or song by the ear alone, that is, by listening
and imitating, as a child would do, or whether it is intuitive;
the answer is not very easy. There is an impulse in song-birds to
express their feelings of pleasure or enjoyment, by giving utterance
to modulated sounds, so pleasing to the human ear, that their song
leads too frequently to their friendly imprisonment. Young birds,
brought up by their parents, and with a vocal pipe best fitted for the
enunciation of the strain of their parents, (or rather male parent,)
rapidly acquire that strain, and soon begin to record, or try it over
in an under tone, and bearing it in memory, break out into full song
when leafy spring returns. Nevertheless, birds, taken early from the
nest, and put under the tuition of other birds, acquire to a certain
extent the song of the latter, often, indeed, apparently perfect; yet,
perhaps, could our ears catch it, we should find that the bird had much
of the parent accent in its acquired language.
Though birds receive ideas of a simple character, and express simple
feelings, understood by each other, through the medium of various
sounds, yet nothing from age to age is thereby added to their
knowledge; they remain what they have been from the commencement of
their creation. Their ears are far less the inlets to knowledge than
their eyes, and this observation applies generally to the lower animals.
Now let us turn to man. Setting aside meaningless sounds and noises,
(some of which, however, through the association of ideas, are very
grateful, as those of the multifarious denizens of a farm-yard,) man
derives both pleasure and knowledge from a definite succession of
sounds, which appeal to his mind, as sound cannot appeal to the mind
of the lower orders. How laughable is the fabled contest of the lutist
and the nightingale, and of the death of the latter disappointed of
the victory--the lutist might have enjoyed the warbling of the bird,
but the bird could not have entered as a rival into the strains of the
lutist. Nevertheless, from personal observation, and from the most
credible authorities, we fearlessly assert, that many animals are
allured by sweet sounds; we have seen rats peeping out of their holes,
listening to airs played on a flute; and sir Walter Scott says,
"Rude Heiskar's seals through surges dark,
Will long pursue the minstrel's bark."
A little lizard (the _anolis_) in the West Indies, and snakes in North
Africa and India, are attracted by the notes of a rude pipe; to deny
this is futile; it has been proved in modern days, and the fact is
noticed in Scripture. Some animals, when certain notes are struck,
or certain keys tried over, are decidedly agitated, and perhaps feel
as we do when some horrid sound "sets our teeth on edge,"--that is,
irritates by a mysterious sympathy the whole nervous system. In the
same way, perhaps, are animals pleased with certain sounds; that is, a
sympathetic tranquillity or pleasing excitement of the nervous system
is produced, and they yield, instinctively, to "the voice of the
charmer."
With regard to ourselves, music (we need not enter into a learned
explanation of what it is) operates far less upon the reasoning than
the instinctive faculties of man. Tones, modulations, swellings, and
cadences, though no words be sung, excite all the emotions of which
our animal nature is capable. But when words are used--when music is
married to immortal verse, and an appeal through language is also made
to the mind, then, indeed, the effect is tremendous. A song shouted
forth in the streets may overturn an empire. Who knows not what was
the effect of the Jacobite songs in Scotland, when Charlie came "o'er
the water?" Who knows not the effects resulting from _Caira_ and
the Marseillaise Hymn? Whose bosom has not beat high when our own
national hymn, when Rule Britannia, and other patriotic airs, have
been energetically and effectively delivered? In fine, who is there
that is not affected by music? very few; it is and has been a natural
expression of human feeling appealing to human feeling, since the time
of Jubal even unto the present day; and Miriam's song of triumph, and
the songs (how mournful!) of the daughters of Judah on the willowy
banks of Babel's rivers, were equally expressive of natural emotions.
Music, then, without words, appeals rather to our animal feelings than
to our reason or mind; music, with suitable words, appeals both to our
animal feelings and our mind; and music, with merely recollected words,
does the same by concatenation of ideas; and this also is often the
result of tones, passages, and cadences, to which we have never heard
words applied; hence, we talk of a lively air, a merry air, a martial
air, a melancholy air; and hence a great poet wrote--
"That strain again! it had a dying fall.
Oh! it came o'er my ear like the sweet south,
That breathes upon a bank of violets,
Stealing and giving odour."
Some airs, again, are solemn, and tend to fill the mind with awe, or a
feeling of devotion; deep strains of melody were those which resounded
through the great temple, when the holy psalms of the shepherd-king
were chanted, and deeply was every heart moved to the worship and
adoration of the living God. Oh, such should ever be our sacred music!
Perhaps we are wrong, but we confess that the sweetest air composed for
an ordinary song, (however pure, elegant, or patriotic that song may
be,) when introduced into the house of God grates upon our feelings. We
divide literature into profane and sacred (meaning nothing offensive
by the term profane)--let, then, music be as strictly divided, so
that the association of ideas which a popular air will, in spite of
ourselves, engender, shall not creep in to intertwine with the sacred
exercise of praise and thanksgiving to our Creator and Redeemer, which
alone should engage the full force of our mind.
The power of music in elevating the mind, in cheering it, or, on the
contrary, in depressing it, has been felt from the earliest ages. When
Saul was troubled in spirit, "David took an harp, and played with his
hand: so Saul was refreshed, and was well, and the evil spirit departed
from him."[16]
[16] 1 Sam. xvi. 23.
We have said, that animals appeal to each other through the organs of
hearing by cries or sounds, nor is man destitute of natural cries,
which are universally understood--the shout of exultation, the scream
of terror, the shriek of agony, the moaning of mental or bodily
suffering, and the sobs of sorrow, speak to every heart. But, besides
these instinctive tones, man acquires a definite language, more or
less extensive, more or less capable of expressing abstract or complex
ideas, and ever in these points bearing progress with the advancement
of the arts, with the civilization and with the religion of the people.
There are some savage tribes who cannot count a hundred, but we can
count to hundreds of millions, till the mind becomes overwhelmed with
the vastness of the numerical progression, which, let each unit stand
for a million of years, would, after all, infringe not on eternity.
Language is the appeal of definite sounds, through the organs of
hearing, to the mind; these sounds are arbitrary; they do not in any
way represent things, or the qualities, or the state of things; for,
indeed, language is based altogether on a system of association--it has
to be acquired; that is, the mind has to be taught to associate certain
sounds with certain mental perceptions; but these sounds do not mean
the same thing in every language or dialect. On this point we need not
insist, neither need we give examples, which must suggest themselves to
every reader, if he reflects that there are other tongues beside that
which he speaks.
Though language consists in a system of sounds uttered by the mouth,
appealing through the sense of hearing to the mind, yet man has
contrived to effect the same purpose through the eye, and hence
is enabled to convey to others at a distance his thoughts, his
observations, his wishes, and views--to transmit to posterity the
results of his labours and researches, or the outpourings of his
genius. His plan is to employ certain marks or characters, drawn or
impressed on paper, bark, wood, metal, or other materials, which
characters shall be understood. These characters, which we call an
alphabet, represent sounds; they are made up into words, and as our eye
runs along them the varying sounds of the words are suggested, and with
them the meaning; this is termed reading, and if we utter the words,
reading aloud.
But there are other characters, not alphabetical, which have been, and
still are, in use, and which are symbols of ideas, and not of sounds.
"While the letters of our alphabet are mere symbols of sounds, the
Chinese characters or written words are symbols of ideas, and alike
intelligible to the people of Cochin-China, Japan, Loo-choo, and Corea,
with those of China itself. As the best practical illustration of a
written character, common to several nations who cannot understand each
other's speech, Mr. Davis adduces the Arabic numerals, common to all
Europe. An Englishman, who could not understand what an Italian meant
if he said _venti-due_, could comprehend him immediately if he wrote
down _twenty-two_. This advantage, which belongs to our numerals only,
pertains to the whole language of the Chinese. The uniformity, however,
in the written character, does not prevent the existence of great
diversities in the oral languages of the neighbouring countries and
China, and even of the separate provinces of the latter country. These
diversities are precisely analogous to the different pronunciation
given to the same numerical characters in the various countries of
Europe.
"To adduce the foregoing example--the number 22, which the Italian
calls _venti-due_, a Frenchman pronounces _vingt-deux_, and an
Englishman _twenty-two_, though all three write them just alike. It
is in this manner that the universality of the Chinese language
extends only to the written character, and that the natives of the two
extremities of the empire, who read the same books, and understand
each other perfectly on paper, are all but mutually unintelligible in
speech. The roots, or original characters of the Chinese, are only
two hundred and fourteen in number, and might, indeed, be reduced to
a much smaller amount by a little dissection and analysis. These are
combined with each other to form other words, or express other ideas,
very much in the same way that the individual Arabic numerals are
combined to express the infinite varieties of numbers. By a species
of analogy, they may be called the alphabet of the language, with the
difference that exists between an alphabet of ideas, and an alphabet of
sounds."[17]
When the Chinese wish to write a European proper name, they have
recourse to a contrivance which in some respects approaches the
phonetic hieroglyphics of ancient Egypt. The Chinese characters when
thus employed do not become alphabetic, but represent the entire
syllable or sound which they express in ordinary use. Thus, if we
suppose A, B, C, to stand respectively in the place of three Chinese
characters, intended to give the name _Maria_, the mode would be thus--
+-+
|A| _Ma_ Jasper
|B| _Li_ Profit
|C| _Ya_ Second in rank.[17]
+-+
[17] See Klaproth's Examen, etc., p. 25.
In ancient Egypt, two modes of writing were practised, namely, the
_common_ and the _hieroglyphic_. There were several kinds of _common_
characters, and also, as it would appear, of _hieroglyphics_. Clemens
of Alexandria distinguishes from both the _hieratic_, which was used by
the sacred registrars. The ancient Mexicans employed pictorial writing;
and of this nature we may consider the Bayeux tapestry, representing
the chief incidents of the invasion of England by William I. Savages
often give information to their friends, or convey their wishes, by
cutting rude figures on the bark of trees, the meaning of which is at
once understood by every individual of the tribe.
On these points we have sufficiently enlarged. Our main purpose is
now to show how great an inlet to knowledge the ear is. To the eye
speak the writings of antiquity, the accumulated wisdom of successive
generations, the experience of sages, and those holy records which
contain the oracles of God, the sacred truths, and the revelation
of the purposes of the Almighty towards a fallen race. It is by
language, as it appeals to the eye, that we commune with the mighty
dead--that we receive into our minds the sublime ideas of a Milton,
the learning of a Bacon, or the philosophy of a Newton. But it is
to the ear that the conversation of ordinary life is directed; the
directions, the requests, the commands that we continually issue forth
or receive--words of congratulation, consolation, encouragement, or
information--the eloquence of the senate or the bar--the strenuous
admonitions or exhortations of the preacher. What a wonderful thing
the mind of man is, that a few atmospheric vibrations on the auditory
nerves, or a few pictures on the retina, should produce sorrow or joy,
hope or fear--should communicate instruction or pleasure--should excite
sympathy or love, contempt or aversion! And, again, how wonderfully
is the organic frame constructed, and adapted to the conditions of
our planet, that light and air should communicate through two of our
external senses with the mind, affording it food for cogitation, stores
of knowledge, and intellectual gratification! Does this arise in any
degree from the superiority of the organs of sight and hearing in man?
Certainly not. The vulture, soaring in the upper sky, far excels man in
the power of vision. Yes, and so does every bird that skims the air, or
hovers in quest of prey over the surface of the great deep. The dog,
the horse, the antelope, and numerous other lower animals, have quicker
ears than man; but then the mind! it is there that the difference lies;
with a weaker sight than is usual, with a more imperfect hearing than
is ordinary, sages and philosophers, and historians and poets, have
left to posterity the brightest productions of mental power. Homer and
Milton were blind.
Through the sense of hearing man communicates orally with man, and man
utters his prayers and praises orally to God, as if God heard with
ears like those of organic beings. It is natural that we should thus
address ourselves to the Almighty, because our conceptions of him are
necessarily limited by the measure of our minds, expansive as regards
the lower creation, but narrow--oh, how narrow!--compared with the
wisdom of the uncreate Eternal. "He that planted the ear, shall he
not hear!"[18] It matters not whether we murmur forth with our lips,
or silently think them in our mind--God hears them. He hears the
language of our heart, the aspirations and vows of our inmost soul:
and he knows, too, (and he alone can know,) whether we be sincere
or the contrary. The tongue of the hypocrite may deceive men, but
not God; nay, we may deceive ourselves by our own verbiage, but God
distinguishes the prayer inspired by the Spirit of truth, from the
empty declaration of excitement.
[18] Psa. xciv. 9.
Thus, then, is the ear an inlet of a vast amount of knowledge to
the mind; it conveys what the eye cannot convey, and it assists the
eye, while in turn by the eye it is assisted; and, indeed, that one
sense shall support another, and be again supported, or corrected,
is ordained by our Creator, who in wisdom has fashioned our mortal
framework, the tenement of an undying soul.
3. _Taste._--The sense of taste conveys to the mind an impression from
objects, very dissimilar to that which is gained through the medium of
the eye or of the ear; nay, dissimilar to that conveyed by the sense of
touch.
The sense of taste resides in the mouth; that is, it pervades the
tongue, the palate, and the pharynx, on which are distributed fine
ramifications of the fifth, eighth, and ninth pair of nerves.
Taste is the appreciation of the savour of bodies, or, in other words,
of certain chemical qualities, which, acting on the nerves, give to our
mind an agreeable or disagreeable sensation; hence the terms sweet,
luscious, acid, vinous, sour, bitter, saline, spicy, aromatic, etc.
Some bodies, however, are tasteless--pure distilled water is tasteless,
and so would a small globe of glass be, however long it was held in
the mouth; but if we put our tongue to a piece of brass, or copper, we
perceive at once a peculiar flavour, resulting from the oxydized film
on its surface mingling with the saliva covering the nervous papillæ of
the tongue.
The organs of taste are placed at the commencement of the apparatus
of nutrition, and their assigned work is to test the quality of the
food received, thereby giving warning lest any noxious substance be
introduced into the stomach. Man, indeed, employs the sense of taste
far less decidedly in this manner than do most other animals; he
is omnivorous; in the north he relishes train-oil and blubber, the
blood of seals, and animal food half raw, while, in tropical regions,
he feeds upon boiled rice or other grain, seasoned with a little
spice, and accounts it a luxury. In both cases, the taste is in
consonance with the requirements of the system, placed under opposite
circumstances. Man, however, acquires by habit an artificial taste,
and comes at last to relish things which he at first disliked, and in
many instances these things are more or less injurious. Nor is this
artificial taste confined only to man--we have seen it in domestic
animals--cats, by nature exclusively carnivorous, will eat boiled
cabbage with relish; the dog will acquire a partiality for bread and
biscuit. On the contrary, some of our herbivorous animals may be taught
to like animal food. For example, in some parts of Arabia, flesh, raw
as well as cooked, is occasionally given to the horses, with fragments
of their owner's meals. An inhabitant of Hamah assured Burckhardt, that
he had often given his horses roasted meat before the commencement of
a fatiguing journey, that they might be the better able to endure it;
this same person, as we learn from the learned traveller, fearing lest
the governor should take from him his favourite horse, fed it for a
fortnight exclusively upon roasted pork, which so excited its spirit
and mettle, that it became absolutely unmanageable, and no longer an
object of desire to the governor.
In the Edinburgh Journal of Natural History we find the following
passage: "We are assured by M. Yvart, that in Auvergne fat soups are
given to cattle, especially when sick or enfeebled, for the purpose
of invigorating them. The same practice is observed in some parts of
North America, where the country people mix, in winter, fat broth with
the vegetables given to their cattle, in order to render them more
capable of resisting the severity of the weather. These broths have
been long considered efficacious by the veterinary practitioners of our
own country, in restoring horses which have been enfeebled through long
illness. It is said by Peall to be a common practice in some parts of
India to mix animal substances with the grain given to feeble horses,
and to boil the mixture into a sort of paste, which soon brings them
into good condition, and restores their vigour. Pallas tells us, that
the Russian boors make use of the dried flesh of the hamster, reduced
to powder, and mixed with oats, and that this occasions their horses
to acquire a sudden and extraordinary degree of _embonpoint_. Anderson
relates, in his History of Iceland, that the inhabitants feed their
horses with dried fishes when the cold is very intense, and that these
animals are extremely vigorous, though small. We also know, that in
the Feroë Islands, the Orkneys, the Western Islands, and in Norway,
where the climate is still very cold, this practice is also adopted;
and it is not uncommon, in some very warm countries, as in the kingdom
of Muskat, in Arabia Felix, near the Straits of Ormuz, one of the
most fertile parts of Arabia; fish and other animal substances are
there given to the horses in the cold season, as well as in times of
scarcity."
In Norway, or at least in some districts of that country, the cattle
are housed during the long winter months, and fed partially upon hay,
but more plentifully on a kind of diet, which, strange and disgusting
as we may think it, is said to be much relished. This consists of a
thick gelatinous soup, made by boiling the heads of fish, and mixing
horse-dung with the broth; so that the boat of a Norwegian farmer
supplies not only himself and his family with the staple portion of
winter subsistence, but his cows also.
We doubt much whether any wild herbivorous animals will feed upon
poisonous plants; they are constantly in the exercise of their
instinctive faculties, and to these faculties the organs of taste
(and smell) administer. Hence they constantly reject all that is
deleterious. But this is not the case with domestic animals, whose
instinct is much enfeebled, or curbed, from the peculiar circumstances
in which they are placed. Hence accidents often happen, to the great
loss of the farmer; for example, both horses and horned cattle will
crop the foliage of the yew, which offers a temptation to them,
especially if underfed, or fed almost exclusively on dry fodder; the
foliage of the yew is poisonous. Cattle often perish from eating the
long-leaved water hemlock, or cowbane, (_Cicuta virosa_.) "When Linnæus
visited Tornea, he found a terrible malady sweeping away the cattle
of the district, and which he at once traced to the long-leaved water
hemlock. Scarcely, in fact, had he crossed the river, and landed from
his boat on the meadow, before he felt convinced of the origin of the
mischief. This deadly plant grew there in abundance, and it appeared
that as soon as the cattle left off their winter fodder, and returned
to pasturage, they died swollen and convulsed; as the summer came on
the mortality decreased, and still more so with the advance of autumn.
"The least attention," says Linnæus, "will convince us that brutes
reject whatever is hurtful to them, and distinguish poisonous from
salutary plants by natural instinct, so that this plant is not eaten
by them in the summer and autumn, which is the reason that in those
seasons so few cattle die; namely, such only as either by accident or
pressed by extreme hunger eat of it. But when they are let into the
pastures in spring, partly from their greediness after fresh herbs,
and partly from the emptiness and hunger they have undergone during
a long winter, they devour every green thing which comes in their
way. It happens, moreover, that herbs at this time are small, and
scarcely supply food in sufficient quantity. They are, besides, more
juicy, and covered with water, and smell less strong, so that what is
noxious is not easily discerned from what is wholesome. I observed,
likewise, that the radical leaves were always bitter, the other not,
which confirms what I have just said. I saw this plant in an adjoining
meadow, mowed along with grass for winter fodder; and, therefore, it is
not wonderful that some cattle, though but a few, should die of it in
winter. After I left Tornea, I saw no more of this plant till I came
to the vast meadows near Limmingen, where it appeared along the road,
and when I got into the town I heard the same complaints as at Tornea,
of the annual loss of cattle, with the same circumstances." Monkshood,
meadow-sweet, hemlock, (_Conium maculatum_,) meadow-saffron, foxglove,
etc., are occasionally eaten by cows, and prove fatal.
The sense of taste varies greatly in different animals; in granivorous
birds, in reptiles and fishes generally, we cannot suppose that the
impressions made on the gustatory nerves are at all delicate; they
swallow their food entire at a single gulp, and their tongue is
covered with a thick or a horny cuticle. Among birds, the carnivorous
tribes, the parrots, and the swans, and true ducks, possess the sense
of taste in considerable perfection. Among reptiles, tortoises and
vegetable-feeding lizards, as the iguana, are, as it would seem,
superior to the others; and among fishes, it is probable that those
which feed on marine or aquatic vegetables, are endowed with a higher
degree of taste than those which prey upon other fishes, which they
engulph at once. It cannot be denied that many insects, as bees,
wasps, butterflies, the house-fly, and various others, enjoy a keen
sense of taste, and relish the sweets which prove so attractive to them.
Among the mollusca, some, at least, are endowed with the sense of taste
in no low degree; the snail and the slug are examples in point, as the
gardener can readily testify.
What information do we gain by the sense of taste? The eye and the
ear conduce to our mental improvement, to our store of knowledge,
to our appreciation of the sublime and beautiful. Eloquence, music,
poetry, painting, sculpture, architecture, scenery--the glory of the
sun, and the moon, and the stars--these appeal to our mind through
the organs of sight and hearing; but the sense of taste administers
rather to our animal than to our intellectual being, and, doubtless,
the pleasures of taste contribute greatly to the enjoyments of our
existence. Taste, then, belongs to us less as spiritual, intellectual,
immortal beings, than as corporeal, mortal beings; nevertheless, it
is part of our nature, implanted in us by an all-wise God, in order
that we should relish the provisions for sustaining life, which he has
so bountifully provided. To pretend that we are indifferent to the
pleasure or the disgust resulting from taste is an untruth--nay, it
is to say that God's gifts to us are not worth our consideration. Our
Lord and Saviour was one of a party at a marriage feast, and when the
wine was exhausted, he turned water into wine, which was superior to
that previously passed round. "This beginning of miracles did Jesus in
Cana of Galilee, and manifested forth his glory."[19] But while, with
a healthy appetite we relish our food, giving thanks to God for his
bounty, let us not be epicures or gluttons; let our moderation be seen;
let us use, not abuse, the gifts of our heavenly Father.
[19] John ii. 11.