Chapter III (1)

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.