CHAPTER III.. The Senses, As the Inlets to Knowledge--Sight and Hearing.

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."

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.

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?" 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!" "Enter not into judgment with thy servant: for in thy sight shall no man living be justified." 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."

Psa. xciv. 9.

Psa. xix. 14.

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."

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."

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. +-+

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!" 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.

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." 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.

John ii. 11.

4. Smell.--On a fine, filmy membrane, which lines the labyrinth of the nasal cavities, are distributed the delicate ramifications of the olfactory nerves, or the nerves of smell. These nerves are constructed for transmitting to the mind impressions arising from the floating exhalations of odoriferous substances. It is through these nasal cavities, principally, that man and quadrupeds breathe; hence the respiration of the air informs us of our proximity to objects disgusting and noxious, or, on the contrary, attractive from their fragrance. Surely we need not adduce instances in proof of our position. The scent of putrescent animal or vegetable matters is in itself a warning to us to retire from the locality of mortific corruption, and escape from the region of disease. How loathsome to our sense are these putrescent effluvia! They nauseate us even to sickness--nay, sometimes almost to fainting; indeed, the writer has seen a violent fit of epilepsy produced by the overpowering and horribly disgusting odour of the matter contained in the scent pouch of a small quadruped, the grison, (Galictis vittata,) which he was dissecting, the sufferer being a practical zoologist, accustomed to the dissecting-room.

But when the voice of the nightingale is heard, and the air is loaded with the perfume of the hawthorn blossom, and of thousands of spring flowers, are we not invited, as it were by a secret call, to walk abroad through woodlands and meadows, contemplating the works of God? We are thus lured to beneficial exercise--to inhale

"The breezy fragrance of the morn"--

to forget the trials of life, and muse upon a still brighter world, where the flowers perish not, where storms come not, and where winter is unknown. Thus, to our bodily health do our senses administer; and thus the sense of smell calls us from the close room of the populous city, into the fresh air of the country--from the crowded town,

"Where houses thick and sewers annoy the air,"

to issue forth on a summer's morn, and breathe the pure air redolent of sweetest odours.

When overpoweringly offensive effluvia disgust us, we endeavour to stop our breath--we breathe at protracted intervals, take in as little air as possible, and endeavour to escape from the infected locality; but do we flee away from the gale bearing the scent of the honey-suckle, the bean-field, or the new-mown hay? It is, indeed, rather to our pleasures, to our mental enjoyment, to our delight, or to our disgust and abhorrence, that our sense of smell administers. We depend little upon it for our discrimination between things acting as poison, and things nutritious or wholesome. How pleasant is the smell of laurel-water or prussic acid--how dull and insipid the smell of wheaten flour! We must not, then, always be guided by our sense of smell, although in general it serves us as a monitor.

The sense of smell is intimately combined with that of taste; indeed, it is a powerful auxiliary to it, for, as a learned writer well observes, "taste, without the aid of smell, would be very vague in its indications, and limited in its range." Nevertheless, savage people, in whom the sense of smell is far more acute than in civilized races, do not appear to possess a greater refinement of taste--indeed, what the former regard as delicacies would be rejected by the latter with abhorrence. Most quadrupeds possess the sense of smell in far greater perfection than man, and are evidently influenced by it in their choice or rejection of food. In the carnivorous tribes this sense is, perhaps, at its highest ratio, and many pursue their prey guided by their olfactory organs alone.

Certain odours are agreeable to some few animals, irrespective of food; but on this point our range of information is limited. The cat delights in the scent of valerian, and some other herbs, although they are not among the articles of this animal's diet; yet to the cat and the dog, the odour of the sweetest flowers yields no pleasure. Birds, in general, are endowed with the sense of smell in a far lower degree than quadrupeds, and the olfactory organs are far less developed. Birds of prey are guided by their keen powers of vision, and, indeed, if we are to trust to the experiments of Audubon, the sense of smell even in the carrion-loving vulture, contrary to the opinion of the ancients, as well as of modern naturalists, is at a low ratio; for, as he asserts, the stuffed skin of an animal will attract a vulture from its "pride of place," in the upper regions of the air. It is true that this assertion has been contradicted by Mr. Waterton, but it is again confirmed by the experiments and observations of Mr. Bachman, which are recorded in Loudon's Magazine of Natural History, viii. 167; and M. Levuillant seems to have considered that it is by the eye chiefly, if not exclusively, that the vulture obtains its disgusting food. The following observations from the proceedings of the Zoological Society will be here, perhaps, not unacceptable:--

March 14th, 1837.--"A paper was read on the habits of the Vultur Aura, by Mr. W. Sells, with notes of the dissections of the heads of two specimens, by Mr. R. Owen. The writer states, that this bird is found in great abundance in the island of Jamaica, where it is known by the name of John Crow; and so valuable are its services in the removal of carrion and animal filth, that the legislature have imposed a fine of £5 upon any one destroying it within a stated distance of the principal towns. Its ordinary food is carrion, but when pressed hard with hunger, it will seize upon young fowls, rats, and snakes. After noticing the highly offensive odour emitted from the eggs of this bird when broken, Mr. Sells relates the following instances which have come under his own personal observation, for the purpose of proving that the Vultur Aura possesses the sense of smell in a very acute degree.

"It has been questioned whether the vulture discovers its food by means of the organ of smell or that of sight. I apprehend that its powers of vision are very considerable, and of most important use; but that it is principally from highly organized olfactories that it so speedily receives intelligence of where the savoury morsel is to be found, will plainly appear by the following facts. In hot climates, the burial of the dead commonly takes place in about twenty-four hours after death, and that necessarily, so rapidly does decomposition take place. On one occasion, I had to make a post mortem examination of a body within twenty hours after death, in a mill-house completely concealed, and while so engaged the roof of the mill-house was thickly studded with these birds. Another instance was that of an old patient and much valued friend, who died at midnight; the family had to send for necessaries for the funeral to Spanish Town, distant thirty miles, so that the interment could not take place until noon of the second day, or thirty-six hours after his decease, long before which time--and a most painful sight it was--the ridge of the shingled roof of his house, a large mansion of but one floor, had a number of these melancholy heralds of death perched thereon, beside many more which had settled in trees in its immediate vicinity. In these cases, the birds must have been directed by smell alone, as sight was totally out of the question.

"In opposition to the above opinion, it has been stated by Mr. Audubon, that vultures and other birds of prey possess the sense of smell in a very inferior degree to carnivorous quadrupeds, and that, so far from guiding them to their prey from a distance, it affords them no indication of its presence even when at hand. In confirmation of this opinion, he relates, that he stuffed the skin of a deer full of hay, and placed it in a field; in a few minutes a vulture lighted near it, and directly proceeded to attack it, but finding no eatable food, he at length quitted it. And he further relates, that a dead dog was concealed in a narrow ravine, twenty feet below the surface of the earth around it, and filled with briers and high canes; that many vultures were seen sailing over the spot, but none discovered it. I may remark upon the above experiments, that, in the first case, the stag was doubtless seen by the birds, but it does not follow that they might not also have smelt the hide, although inodorous to the human nose; in the second case, the birds had been undoubtedly attracted by the smell, however embarrassed they might have been by the concealment of the object which caused it. I have, in many hundred instances, seen the vulture feeding upon small objects under rocks, bushes, and in other situations, where it was utterly impossible that the bird could have discovered them but through the sense of smell; and we are to recollect, that the habit of the vulture is that of soaring aloft in the air, and not that of foraging upon the ground."

To this account are appended the details of a minute comparison, by professor Owen, of the olfactory nerves and the olfactory branch of the fifth pair in the Vultur Aura, with those of the common turkey and the goose. The learned anatomist concludes by saying, "the above notes show that the vulture has a well-developed organ of smell, but whether he finds his prey by that sense alone, or in what degree it assists, anatomy is not so well calculated to explain as experiment."

It is far from being impossible that Mr. Waterton and Mr. Wells on one side, and Mr. Audubon and his party on the other, may be both correct, for in different species of vulture the power of smell may greatly differ; we know that it does among carnivorous quadrupeds, which seek their prey, some chiefly by sight, others by their acuteness of scent. Among reptiles, the sense of smell appears to be at a low ratio, nor can we suppose that it is acute in fishes. In fact, in fishes the nasal cavities are rudimental, and do not communicate with the organs of respiration. They are nothing more than blind sacs, placed one on each side in front of the head, with two external openings appertaining to each sac. The principal entrance is valvular, and on a curiously plaited membrane in the sac itself, or on tufted or arborescent filaments, are the ramifications of the olfactory nerves distributed. That fishes are attracted or repelled by the odorous effluvia of bodies, diffused either through the water itself or through the air which the water contains, is too well ascertained to be denied. Fishes, in fact, are attracted by certain odoriferous substances, and anglers often use baits impregnated with some volatile oil.

On this subject see Izaak Walton's "Complete Angler."

We cannot for a moment doubt that insects smell; that ants and bees are greatly directed by this sense in their search after food; that carrion-loving beetles are thereby guided from a distance to their repast; that the flesh-fly is led to putrescent animal substances; and we know that the flesh-fly is sometimes deceived by the smell of certain plants emitting a cadaverous odour, and deposits her eggs upon them, the larvæ perishing for want of proper food. In what organ the senses of smell in insects are placed does not appear very plain, and the like observation applies to the crustacea, as crabs and lobsters, for which baited traps are set, and into which they are allured by their sense of smell.

No distinct organs of smell have been discovered in the mollusca, yet it is incontestable that some of these creatures are capable of appreciating odours. We cannot suppose that in the highly-organized and savage cuttle-fish this sense is wanting; and we know that snails and slugs are attracted from a distance by the odour of the favourite plants or fruits on which they feed. The garden slugs are fond of animal food, as we can testify, and they will pick bones with relish; we have seen the hollow of a marrow-bone thrown into the garden filled the next morning with slugs, which had completely cleaned it.

Whether the bivalve mollusks, as mussels, oysters, clams, etc., have any definite sense of smell, we cannot ascertain, but we conjecture that they are endowed with the sense of taste, for they know what to accept and what to refuse.

We have said that man derives pleasure or disgust from the exercise of the sense of smell, and is greatly directed thereby what to choose and what to avoid; yet this sense harmonizes with those of sight, hearing, and more particularly of taste, to render this world delightful to us, if we use God's gifts aright. Has he not scattered the loveliest flowers in garden and meadow? Has he not created fruits that gratify alike the sight, the touch, the taste, and the smell? Has he not spread the beauties of nature around us? Was not the garden of Eden prepared for our first parents? Yes; but sin has entered the world, and over flower and fruit has been the "trail of the serpent."

A few passages from the Scriptures, on which we need not comment, will serve to show the figurative notice of, or reference to this sense by the sacred writers, in order to influence the mind of man through an appeal to his own sensations. "An odour of a sweet smell, a sacrifice acceptable, well-pleasing to God," Phil. iv. 18. Works pleasing to the Lord, deeds of charity and mercy, done by the believer as a testimony of his lively faith, and a proof to the world that faith engenders good works; such works, and not those of the pharisee, are an odour acceptable to God. "Walk in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweet-smelling savour," Eph. v. 2. Let us, who call ourselves Christians, so walk, that our conduct before men may be after the pattern of Him, who, in love to a fallen race, offered himself as a sacrifice fragrant unto God the Father, that we might escape the sword of justice. When Noah offered burnt-offerings on the altar, "the Lord smelled a sweet savour," Gen. viii. 21; and to Him even now, O reader, will be fragrant true penitence and faith in that Mediator, of whom the sacrifices under the primitive dispensation were but types, and in this sense only did they waft incense to the throne of the Almighty! The language is altogether figurative; but how pertinent to our feelings, and therefore how clear to our understanding, and how forcible!

5. Touch.--Of all the senses, not one is so important to us as that of tact or touch. It is the foundation, as it were, of all our knowledge of the material world, and according to their elevation in the scale of being do animals enjoy this sense in greater perfection, and possess organs in which it is more especially concentrated. We here distinguish, between mere feeling and touch. We consider the wings of the bat, and the antennæ of insects, rather as feelers than as organs of exact appreciation. The sense of feeling is diffused over the whole surface of our body; but the sense of touch, so far as man is concerned, resides in the hand, and especially in the pulpy tips of the fingers.

It is true that we use the word feel when we test the qualities of bodies with our hands, and in this sense our hands are feelers. But we derive a knowledge from the use of our hands, which no other animal derives from the exercise of any organ of tact it may possess. Nor is this to be wondered at, for in all other animals tact or touch administers only to their physical necessities. For example, the sense of touch in the pulpy end of the beak of the snipe or woodcock must be exquisite--multitudinous are the nerves supplying that part--for even the soft worm or larva in the oozy ground is felt, and the finger of man would most probably fail here; but in man the sense of touch appeals to the mind, and communicates mental pleasure, mental instruction, or even mental disquietude. Even as discords in music, or grating sounds, such as the filing of a saw, or the rubbing of cork against a wall, excite the nervous system through the mind, so does the sense of touch disturb the mind and body when that which is touched is discordant. A lady of the writer's acquaintance, by no means timid, and by no means afraid of snakes, was induced to let a common snake glide through her hand; she bore the sensation with firmness, but she nearly fainted when the snake had crept through her grasp, and described the working of the reptile's ribs and abdominal plates as communicating an indescribable sensation. Yet that snake was a sort of pet, and she used to stroke its head, and feel its lambent tongue quiver against her hand. She was not afraid, but the sensation jarred like discordant notes.

Were persons to write down their experiences of the pleasing and unpleasing sensations derived through the medium of the different senses, and were those notes collected together, we should have a mass of most interesting and instructive information, well worthy the study of a physiologist. After all, however, the sense of touch or tact gives less pleasure to man than that of sight, hearing, taste, or smell; it appreciates neither colours nor harmony, nor the flavour of luscious viands, nor the odour of flowers and perfumes; but it communicates greatly to his store of information. It is a "matter of fact" sense, and though an old poet has said--

"Have you felt the wool of the beaver, Or swan's down, ever?"

it is not one of the senses which figure on the page of poetry or romance.

We discriminate, then, between the sense of touch and that of mere feeling. Most probably all animals, even the lowest mollusks, feel,--nay, even animals in which no nerves are to be discovered, as the acalephæ, or jelly fishes; but touch is a refinement upon feeling, which is restricted within certain zoological bounds. A learned writer says: "The conditions on which the perfection of the sense of touch depends are, first, an abundant provision of soft papillæ, supplied with numerous nerves; secondly, a certain degree of fineness in the cuticle; thirdly, a soft cushion of a cellular substance beneath the skin; fourthly, a hard resisting basis, such as that which is provided in the nails of the human fingers; and lastly, it is requisite that the organ be so constructed as to be capable of being readily applied, in a variety of directions, to the unequal surfaces of bodies, for the closer the contact, the more accurate will be the perceptions conveyed. In forming an estimate of the degree of perfection in which the sense is exercised in any particular animal, we must accordingly take into account the mobility, the capability of flexion, and the figure of the parts employed as organs of touch."

Dr. Roget.

This is decidedly true as regards the higher orders of creation; but let us look at insects--do not bees, and wasps, and flies feel? can we watch a fly brushing its head and wings, and rubbing its little paws against each other, without an assurance that it enjoys the sense of touch? and what shall we say of the spider, that feels at each thread, and "lives along its line?" Surely its sense of touch must be sufficiently acute; yet it is limited to a certain given object, and the spider gains only that information which bears upon its animal necessities. But the sense of touch gives to man a number of the properties of matter, which he retains as abstract ideas, such as dimension, form, condition of surface, hardness, softness, elasticity, compressibility, fluidity, quiescence, motion. In many and most important respects it assists the eye; and, indeed, the senses of sight and of touch appear to be correctors and supporters of each other. As in the case of every other sense, accuracy is greatly improved by habit, yet the qualities of matter, under the dominion of touch, are ascertained in so correct a manner that we are scarcely ever deceived by the knowledge thus acquired.

Dr. Fleming, in his "Philosophy of Zoology," thus writes: "The sense of touch appears in man to be able to obtain nearly all the information, with regard to external objects, which it is capable of receiving. In a few instances, the lower animals surpass us in the delicacy of the sense, as the bat, which is warned indirectly by its aid of the presence of bodies previous to coming in contact with them. The feelers of insects are likewise better adapted for exploring the condition of the surface of bodies than any organ which we possess. But in all these the sensibility of touch is limited to particular qualities, or confined within narrow bounds. The human hand, on the contrary, by its motions, the pliability and strength of the fingers, and their softness, is the most extensive and perfect organ of touch possessed by any animal."

The accuracy of the sense of touch is greatly improved by habit; and when its resources are in constant demand, as in the instance of persons deprived of sight, or born blind, its discriminating powers are wonderfully increased. The same observation applies also to the sense of hearing, which in blind persons generally is extremely acute and accurate in its perceptions. In a Monthly Volume, published by the Religious Tract Society, and entitled "Comparisons of Structure in Animals: the Hand and the Arm," the reader will find a general account of the structure and uses of the anterior limbs of man and the lower animals, and of the substitutes for the hand, as an organ of touch and prehension, with which many of the latter are provided.

Dr. Fleming regards the "sense of heat" as distinct from that of touch, and, in fact, as claiming to be one of the senses. "The sense of touch," he writes, "is exclusively occupied with examinations of the conditions of resistance. Contact, therefore, is indispensably requisite for enabling the organ to act upon the object, and muscular exertion to examine its condition. Neither of these is necessary to enable the sense of heat to act. Caloric rays emanate from a heated body, though at a distance; and in order to ascertain their direction and intensity no muscular effort is required. When the heated body happens to be in contact with us, we in like manner examine its conditions in reference to temperature without any muscular exertions, or, rather, we try to avoid them. Thus, when I lay my hand upon the table to examine its hardness or smoothness, I make an obvious muscular effort with my fingers; but when I lay my hand upon the table to examine its temperature, I endeavour to check all motion, so as to keep my hand in the same position. These qualities of the sense of heat sufficiently distinguish it from that of touch, with which it has been confounded, and justify its establishment as a distinct power of perception."

It is true that we cannot test caloric by the touch, but it does not appear to us that an appreciation of caloric involves any other sense than that of ordinary cutaneous feeling; the feeling of heat or cold is a mere sensation, agreeable or painful as circumstances may be, and it is natural that we should wish to experience that temperature which is most congenial to us. We say that marble is cold and wood warm, yet both may be of the same temperature; but the marble produces a sensation of coolness, because it rapidly abstracts caloric from the part applied to it; the skin is, in fact, a very imperfect thermometer, yet sufficient for all ordinary purposes. It conceals the machinery of our bodies, giving beauty of outline and appearance, and being provided with a most minute network of nerves of sensation, it gives us warning by the pain experienced of what things are to be avoided. "A burned child dreads the fire" is an old saying, and a boy who has been stung by a nettle will not rashly meddle with the plant again.

All our senses require training and education; they are taught, even as we are taught language. It is some time before the infant sees distinctly, or forms any idea of size, proportion, or distance; long before it hears accurately, and understands a word of speech; longer still before it discriminates between musical notes; it is long before delicious odours are relished, and long before there is much distinction of flavour in food, for instinct directs the infant to its mother's breast, and for many a year sweet viands are chiefly acceptable. Habit, exercise, practice, then improve the power and acuteness of the senses, but simple feeling is blunted by habit and exercise.

It is, we think, Mr. Lane who tells us, that in Egypt and elsewhere, persons who have hoarded wealth are in the habit of inflicting the bastinado on themselves, increasing the number of strokes by degrees, in order to inure themselves to a mode of extortion of which they are constantly in dread. They hope to be able to weary out their tormentors, or convince them by endurance of their poverty, and so preserve their bags of gold and silver. Idolatrous devotees in India accustom themselves to self-inflicted torture, and feel much less than we might suppose; nay, even in our own country, in times of spiritual darkness, when by mortification and penance men hoped to merit heaven, how many have worn a shirt of horsehair till custom had made it no hardship! The ancient Britons bore, almost unclothed, the severities of winter; and we have read a story, but where we cannot recollect, to the following purport:--A North American Indian was asked, how, nearly naked as he was, he bore with such ease the summer's heat and the winter's cold; he asked the inquirer, how his face, exposed to the weather, endured the changes. My face, said the white man, is hardened to it; and I, retorted the red man, am face all over.

We have said it is long before an infant is in the full use of its bodily senses: now with regard to feeling the infant is acutely sensitive; but who ever saw a child of a few months old examine the qualities of objects by the touch? it cannot even manipulate; it cannot use its hands; it has to learn the art of touch, and to improve by practice and the exercise of the mind. For example, some persons will pass a piece of silk or cloth between their fingers, and tell you its quality; and so with respect to other things; this is the result of attention and exercise.

No one is born without the organization necessary for the development of the sense of touch, for if the arms and hands be deficient, some other part, as the lips or tongue, will take up the function, and this alone shows what education effects; but if a person be born deaf, or blind, or incapable of taste and smell, (which latter appears to be very rare, if, indeed, the case ever occur,) no other part can supply the loss; but the loss, as far as the sight at least is concerned, is partly compensated for by the elevation of the sense of touch; and in this we see the immediate bearing of these two senses on each other.

The boy born blind, upon whom Cheselden so successfully operated, believed, when first he saw, that the objects touched his eyes, as the things which he felt touched his skin; consequently he had no idea of distance. "He did not know the form of any object, nor could he distinguish one object from another, however different their figure or size might be; when objects were shown to him which he had known formerly by the touch, he looked at them with attention, and observed them carefully, in order to know them again; but as he had too many objects to retain at once, he forgot the greater part of them, and when he first learned, as he said, to see and to know objects, he forgot a thousand for one that he recollected. It was two months before he discovered that pictures represented solid bodies; until that time he had considered them as planes and surfaces differently coloured, and diversified by a variety of shades; but when he began to conceive that these pictures represented solid bodies, in touching the canvass of a picture with his hand he expected to find something in reality solid upon it, and he was much astonished when, on touching those parts which seemed round and unequal, he found them flat and smooth like the rest. He asked which was the sense that deceived him--the sight or the touch. There was shown to him a little portrait of his father, which was in the case of his mother's watch; he said that he knew very well that it was the resemblance of his father, but he asked with great astonishment how it was possible for so large a visage to be kept in so small a space, as that appeared to him as impossible as that a bushel could be contained in a pint."

Phil. Trans., 1728.

In the Philosophical Transactions of 1826 will be found the account of a case by Mr. Wardrop, which is very interesting; it is that of an intelligent female of mature age, who was born blind; in her infancy, operations were performed on both of her eyes, but they failed, one eye being irrecoverably destroyed, and the other useless from closure of the pupil; on this eye Mr. Wardrop successfully operated: but it was not with joy that objects for the first time were perceived; she was confused by the appearance of a new world, now for the first time opened to her sense of sight; hitherto she had known it only through the sense of touch, and touch and sight had still to be reconciled. "On the sixth day, she said that she saw better than she had done on any preceding day, but I cannot tell (said she) what I do see; I am quite stupid. She seemed, indeed, bewildered from not being able to combine the knowledge acquired by the senses of sight and touch, and felt disappointed in not having the power of distinguishing at once by her eye, objects which she could so readily distinguish from one another by feeling them.

"The next day, on examining with the eye the tea-cups and saucers, and being asked what they were--I don't know, she replied; they look very queer to me, but I can tell in a minute when I touch them. So with an orange which was lying before her, she could make nothing of it until she actually touched it. When the experiment was made of giving her a silver pencil-case and a large key to examine with her hands, she discriminated and knew each distinctly; but when they were placed on the table side by side, though she distinguished each with her eye, yet she could not tell which was the pencil-case and which the key.

"In six weeks after the operation, she returned home. At this period, she had learned a great deal; she had acquired a pretty accurate notion of colours, but with regard to forms and distance she was still very ignorant. She had also great difficulty in directing her eye to an object, so that when she attempted to look at anything she turned her head in various directions, until her eye caught the object of which it was in search. She still entertained, however, the same hope, which she expressed soon after the operation, that when she got home, her knowledge of external things would be more accurate and intelligible, and that when she came to look at those objects which had been so long familiar to her touch, the confusion which the multiplicity of external objects now caused would in a great measure subside."

Thus, then, it is from an association between the senses that correctness and precision in any one sense are acquired; and especially do the eye and hand support each other, and supply each other's deficiencies till both have learned their perfect lesson. I can stretch my hand out to any object before me with certainty, so truly does the eye tell me whether it is within my reach or not, but the eye first learned that faculty from the hand, after long discipline and many trials. Afterwards the eye speaks a silent language to the hand, and is understood. Under what merciful circumstances are they placed that possess all their faculties and senses! but, alas! how many are there that never dream of thanking a merciful God for his unbounded kindness! nay, there are some atheistical materialists who believe, or rather pretend to believe, that man's exquisite organization, and that of animals and plants, is self-developed--how, they do not condescend to explain; for, granting them their premises, namely, that matter is eternal--and what then? it must be inert, and neither the laws of vitality nor chemistry, involving electricity and galvanism, could be taken on by inert particles--all would be chaotic, did not God govern, arrange, and order all. It is he who has created man, and, fallen as man is, he still is an object of God's care; for he sent his well-beloved Son into the world for our redemption, and the time is coming in which all nations shall know the Lord, and adore him in sincerity and truth.

Like all the organs of our senses, the hands are the instrument of wickedness to sinful man; his sense of touch is the inlet of evil. How refined that sense in the adroit pickpocket, but to what an ill purpose is it devoted! How dexterous are the hands of the shoplifter, but to what a wretched course have they been trained! The hand grasps the pen; every stroke is guided by its delicate sense of touch; it obeys the mind; and, oh! what dictations from the depraved mind have polluted society! God has been reviled, Jesus Christ denied, the Holy Spirit mocked, and in letters written by hands which the almighty Maker and Preserver had endowed so supereminently. Their hands are mouldering; dust has returned to dust; but where are the immortal spirits which directed those hands to scatter poison abroad? It is not for us to inquire or judge. Let us, ourselves, be watchful, and let our hands be clean in the sight of God; let us be diligent in business, serving the Lord; let us fight the good fight of faith, and lay hold on eternal life!

Though we have described the hand as the great and main organ of touch, let it be understood that it is not the first called into operation. The hand requires rigid discipline; for a long period it is useless as an organ of tact; yet, when educated, how perfect, how precise! But it is made what it is by education. Our ideas coincide exactly with those of sir Charles Bell, who thus writes: "The lips and the tongue are first exercised; the next motion is to put the hand to the mouth in order to suck it; and no sooner are the fingers capable of grasping, than whatever they hold is carried to the mouth; so that the sensibility to touch in the lips and tongue, and their motions, are the first inlets to knowledge, and the use of the hand is a later acquirement."

Another passage from the same gifted writer is as follows: "The first office of the hand, then, is to exercise the sensibility of the mouth; and the infant as certainly questions the reality of things by that test, as the dog does by its acute sense of smelling. In the infant, the sense of the lips and tongue is resigned only in favour of the sense of vision, when that sense has improved, and offers a greater gratification, and a better means of judging of the qualities of bodies. The hand very slowly acquires the sense of touch; and many ineffectual efforts are seen in the arms and fingers of the child, before the direction of objects or their distance is ascertained. Gradually the length of the arm, and the extent of its motions, become the measure of distance, of form, of relation, and perhaps of time."

Throughout life, the sensibility, as it regards tact, of the tongue and lips continues paramount; we can feel the slenderest hair with our tongue, which our hands would not appreciate: but, on the contrary, size, form, distance, order, and the general qualities of matter, can only be gained through the hand, after a persevering discipline. A blind man may examine a statue with his hands, and pronounce upon its excellence; and this fact suggests to us an idea of sir Charles Bell, who says: "The knowledge of external bodies, as distinguished from ourselves, cannot be acquired until the organs of touch in the hand have become familiar with our own limbs. We cannot be supposed capable of exploring anything by the motion of the hand, or of judging of the form or tangible qualities of an object pressed against the skin, before we have a knowledge of our own body as distinguished from things external to us." From these remarks we naturally slide into a dissertation on a sense, allied to that of touch, but yet different--we mean muscular sense.

6. Muscular sense.--God in his infinite wisdom has constructed all living things, and no doubt there is much yet for the philosopher to discover in the organization of animal bodies; there is, moreover, something that he never will understand, namely, life intrinsically considered, and the manner in which the immortal spirit and the dying body communicate with and influence each other. But though these points must ever remain a mystery, still there are those the obscurity of which science has to a certain degree dispelled, and it was reserved for a late scientific anatomist to prove to the world, that the nerves of sensation and the nerves of motion are essentially distinct, although interblended together they pervade every muscle. Hence, as this philosopher observes, (we mean sir Charles Bell,) we are sensible of the action of our muscles, because these muscles have two classes of nerves; and he found that in exciting one of these the muscle contracted, while on exciting the other no action took place. The nerve which had no power to make the muscle contract was the nerve of sensation.

Continuing his experiments, he proved that there is a nervous circle connecting the muscles with the brain, that one nerve is not capable of transmitting what is called the nervous spirits in two different directions at one instant of time, but that for the regulation of muscular action there is a nerve of sensibility, to convey a sensation of the condition of the muscles to the sensorium, as well as a nerve of motion for conveying the mandate of the will to the muscles. He also demonstrated, that in their distribution through the body, the nerves which possess these two distinct powers of conveying sensation, and of exciting the muscles to contraction, are wrapped up, or, as it were, woven together in the same sheath, and that they present to the eye the single appearance of one nerve. It was only by examining the nerves at their roots, that is, where they arise from different tracts of the brain and spinal marrow, and before they coalesce, that this philosophic anatomist succeeded in demonstrating their distinct functions. In the face, the nerve of motion passes by a circuitous route, apart from the nerve of sensation, to be distributed to the muscles; and, therefore, the distinct characters of these two nerves were, as sir C. Bell asserts, more easily proved by experiment than in any other part of the body.

The nerves of sensation then feel, or rather recognise, those actions of the muscles which are excited through the medium of the nerves of contraction, and these nerves of contraction, as far as the voluntary muscles are concerned, obey the commands of an immaterial being--mind, spirit, soul; in the lower animals, so far as we know, this principle is transient, for they have no ideas of life, or of death, or of futurity; but in man, the soul is immortal, and for the future bliss of this immortal essence revelation affords a certain guide.

Now the sense of touch and the muscular sense have, by most writers, been confounded together; hence, we are told that weight is determined by touch, but this is erroneous; it is determined by the muscular agency and sense, under the dictation of the will. The abbé Nollet says of touch, that "it not only puts it in our power to judge of what makes an impression upon us, but also of what resists our impulsions." Here the sense of touch and the muscular sense are confounded together. The agency of touch has nothing to do with weight or resistance; and herein we differ from Dr. Fleming, and agree with sir Charles Bell, by whom, indeed, this muscular sense was first demonstrated. To feel, or touch, is not to resist or struggle. Laocoon, striving with the serpents, resists--his muscular sense is called into action, as is that of the wrestler when engaged in a trial of skill or strength; but what has muscular feeling to do with that tact, which distinguishes between the texture of tissues, or the smoothness or roughness of bodies? For ourselves, we refer the sensations of hardness and softness rather to a muscular sense than a simple sense of touch; but, as we have said, the sense of touch and the muscular sense, or sense of resistance, inter-amalgamate with each other, nevertheless, there is a definite muscular sense of which every one is conscious, and it is by the education of this sense that the infant learns to walk, the man to ascend the lofty ladder, or traverse the ledge of the precipice. It is not connected with feeling alone, but also with sight; and, indeed, the senses of sight, feeling and support, or resistance, are in as close relationship, as are those of smell and taste. This is exemplified in the fencer, whose muscular sense obeys his eye, and in the artist, who strikes out the bold outline of a figure on the canvass.

This muscular sense is sometimes called the sense of motion; and rightly, because it is a feeling of muscular action; not a feeling of extraneous bodies, but a feeling of what passes within ourselves, as far as such feeling is permitted (many internal operations go on without our consciousness)--a feeling of what we do, according to our will, and the permission of God Almighty. Does the uninstructed man, who looks upon and admires a lovely landscape, think about the inverted picture on his retina? No. Does the athlete who lifts a great weight think of the biceps, or the deltoid, or the pectoral muscles? No. But does he not feel, while he strives, while he struggles, while he runs, an internal consciousness of action totally distinct from touch?

This perception is termed by sir Charles Bell the "muscular sense." He thus illustrates his idea: "When a blind man, or a man with his eyes shut, stands upright, neither leaning upon nor touching aught, by what means is it that he maintains the erect position? The symmetry of his body is not the cause. The statue of the finest proportions must be soldered to its pedestal, or the wind will cast it down. How is it, then, that a man sustains the perpendicular posture, or inclines in a due degree towards the winds that blow upon him? It is obvious, that he has a sense by which he knows the inclination of his body, and that he has a ready aptitude to adjust it, and to correct any deviation from the perpendicular. What sense, then, is this? for he touches nothing, and sees nothing; there is no organ of sense hitherto observed which can serve him, or in any degree aid him. Is it not that sense, which is exhibited so early in the infant in the fear of falling? Is it not the full development of that property which was early shown in the struggle of the infant, while it lay in the nurse's arms? It can only be by the adjustment of muscles that the limbs are stiffened, the body firmly balanced and kept erect. There is no other source of knowledge but a sense of the degree of exertion in his muscular frame, by which a man can know the position of his body and limbs, while he has no point of vision to direct his efforts, or the contact of any external body. In truth, we stand by so fine an exercise of this power, and the muscles are, from habit, directed with so much precision and with an effort so slight, that we do not know how we stand. But if we attempt to walk on a narrow ledge, or stand in a situation where we are in danger of falling, or rest on one foot, we become then subject to apprehension; the actions of the muscles are, as it were, magnified, and demonstrative of the degree in which they are excited.

"We are sensible of the position of our limbs; we know that the arms hang by the sides, or that they are raised and held out, although we touch nothing and see nothing. It must be a property internal to the frame by which we thus know the position of the members of our body; and what can it be but a consciousness of the degree of action, and of the adjustment of the muscles? At one time, I entertained a doubt whether this proceeded from a knowledge of the condition of the muscles, or from a consciousness of the degree of effort which was directed to them in volition. It was with a view to elucidate this that I made the observations which terminated in the discovery that every muscle had two nerves; one for sensation, and one to convey the mandate of the will, and direct its action. I had reasoned in this manner: we awake with a knowledge of the position of our limbs; this cannot be from a recollection of the action which placed them where they are; it must, therefore, be a consciousness of their present condition. When a person in these circumstances moves, he has a determined object, and he must be conscious of a previous condition before he can desire a change, or direct a movement."

In walking, riding, swimming, and other bodily exercises; in writing, playing on the piano, or any other instrument of music, the muscular sense is called into activity, and co-operates with the senses of sight, touch, etc. Muscular exertion is in itself pleasurable, when not pushed too far; and, indeed, the healthy condition, both of the body and mind, results from muscular exertion, and the alternations of activity and repose. The appointment of man, after the fall, to a life of labour, was a judgment tempered by mercy. Man is not destined to lead a life of sloth or supineness, but, urged on by his natural wants, he cultivates the ground, he tames the wild beast of the forest or mountain, he builds houses, he constructs ships, he clothes himself with fabrics, he surrounds himself with the comforts, the decencies, the luxuries of life, and in every work which his hands find to do his muscular sense is in requisition; it is this sense which appreciates resistance, which enables us to balance our bodies, to move with gracefulness, to run, to walk, to leap, to throw the shuttle with precision, or wield the hammer with skill. It is improved by education; the child learns first to walk, and then to run and leap, and in due time to know its own strength, and also the best mode of employing that strength, without reflecting upon the laws of mechanics, or any philosophic theories. It is evident, then, that we have "a perception of the condition of the muscles previous to the exercise of the will," and that with respect to the hand, "it is not more the freedom of its action which constitutes its perfection, than the knowledge which we have of these motions, and our consequent ability to direct it with the utmost precision."

That the lower animals are endowed with this muscular sense cannot be doubted. It enables the tiger to spring with accuracy upon his prey, the cat upon the mouse, the greyhound in pursuit of the hare when to make the fatal snap, and the horse to leap the fence, which his eye tells him is within his power; it teaches the loris to creep upon its victim, as slowly but as surely as the hand on the clock-face traverses the dial-plate, and attains the given number; it is immediately connected with instinct, and man, when he steps aside to avoid a threatened stroke, or raises his arm to parry a blow, puts the muscular sense into exercise.

The muscular sense is, to use a homely expression, an every-day working sense; touch and sight are its prime supporters, and to these in turn it lends its aid. Nevertheless, to a certain degree it is independent of them; the infant seeks the breast as it were by an instinctive impulse, or applies the coral to its mouth; and in the dark as well as in the light, we transmit our food directly and precisely to the organs of mastication and deglutition, without thinking upon the manner in which the varied actions are performed, or even transiently noting them. We will to perform an act within our power of achievement, and by the complicated action of muscles, nerves, vessels, and bones, we accomplish our object, at the same time, perchance, we know not the origin and insertion of a single muscle, the direction of a single nerve, the course of a single artery.

The muscular sense is, in fact, in perpetual exercise; it is intimately connected with self-consciousness, for we feel that we corporeally exist, that other bodies exist around us, that they resist us, that they lead us to calculate our own powers, nor will all the arguments of the school of Berkeley convince us that we exist only in idea. When Dr. Johnson stamped upon the ground to disprove Berkeley's idea, he was right.

So much for the senses with which we are endowed, and the information which the mind receives through their respective channels. They teach us all that we know concerning the qualities of matter, and they subserve many of our enjoyments--they are essential to our comfort, our activity, our usefulness; but we gain through their medium no abstract truths, no determinate principles. These are elaborated in the mind itself by its own self-analysis; but, then, they do not teach us our own position as it respects time and eternity. The wisest of the heathens of Greece or Rome lived in doubt, entangled in the mazes of a vain system of philosophy; and though they might believe in a god, or in gods, deducing their arguments as to the existence of an all-powerful Being from the works of nature, and from that internal conviction which seems common to the human race--they knew nothing of His attributes, of his laws, of his requirements, of man's fallen nature, of the intrinsic sinfulness of the heart, of the means of grace, of a hope of glory. They could write noble poems, deep philosophic treatises, histories of empires, narratives of events, details of characters, descriptions of works of art; they could carve statues of matchless perfection, and build temples of surpassing splendour. They displayed an intellectual pre-eminence, which still sheds a lustre over the civilized world. Who by searching can find out God? Unless God graciously reveals himself to us, a true knowledge of him in our fallen state is impossible; the capabilities of our minds are, after all, but limited; and though, through reflection on the evidences of our senses, we may come to the conclusion that there is an omnipotent Power, we remain in ignorance as to what that Power is, and as to our relationship thereunto. Hence, then, the necessity of information beyond what the mind can gain through the senses, or by its own reflex operations; we are conscious of our position as respects the lower animals, and we have natural longings after and hopes of immortality; the soul whispers to itself, Non omnis moriar, I shall not all die; but here, were it not for revelation--a revelation from God, we should be left in darkness.

God gave a revelation of his will to Adam; our first parents transgressed, but then in mercy a promise was given, that the seed of the woman should bruise the serpent's head. God gave a further revelation of his will to Moses, with promises and commands, and elected from among the nations a peculiar people, of whom from the line of Jesse after the flesh should arise the Messiah; in Him are all the promises and prophecies centred, and through him the great revelation of God's purposes of mercy to a fallen world was ordained to be published. The Messiah came; He of whom Isaiah prophesied; the despised and rejected of men--God manifest in the flesh. The prophet's words were verified, "He was wounded for our transgressions, he was bruised for our iniquities: the chastisement of our peace was upon him; and with his stripes we are healed."

Isa. liii. 5.

This is the Christian revelation, which, while it shows us our lost and sinful nature, our utter unworthiness, and the insufficiency of good works for salvation--whilst it humbles our pride, and self-sufficiency, and teaches that our place before God is in the dust, yet it speaks of joy and peace, for it points out what is all-important, the mode of redemption, the forgiveness of our sins, our adoption as heirs of the kingdom of heaven. "In this was manifested the love of God toward us, because that God sent his only begotten Son into the world, that we might live through him." God reveals himself in his works as a God of wisdom and power; but here he discovers himself as a God of truth, justice, and mercy. He reveals himself as the triune Jehovah, the Father, the Son, and the Spirit, one God for evermore; and he gives us a revelation of the plan of salvation. And what is this plan? it is one by which justice and mercy are reconciled. "Without shedding of blood is no remission" of sins. The Son of God, according to the Divine promise, took upon himself our human nature, dwelt upon earth, sinless, and offered himself up as a sacrifice for sin on Calvary. He "who, being in the form of God, thought it not robbery to be equal with God: but made himself of no reputation, and took upon him the form of a servant, and was made in the likeness of men: and being found in fashion as a man, he humbled himself, and became obedient unto death, even the death of the cross. Wherefore God also hath highly exalted him, and given him a name which is above every name: that at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth; and that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father."

1 John iv. 9.

Philippians ii. 6-11.

Of the sacrifice of Christ, the crowning sacrifice, those of the Mosaic ritual were types or emblems. By his sacrifice the claims of the law were satisfied. What is required of us? Belief in the atonement. "Jesus said unto Martha, I am the resurrection and the life: he that believeth in me, though he were dead, yet shall he live: and whosoever liveth and believeth in me shall never die." A true, living, justifying faith is the gift of the Holy Spirit, who sanctifies and renews the heart of the genuine believer. "The carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be;" but when the mind is enlightened by grace Divine, the awfulness of sin is perceived and deeply felt, true repentance is awakened, love and gratitude to God for every mercy are excited, and the soul is warmed with adoration. Then does the converted man become prayerful and watchful; then is he zealous in God's cause, and anxious for the conversion of those that live in the darkness of ignorance, and travel along the broad road that leadeth to destruction. Then will he be patient and trustful under trials and affliction, and justify God's dealings with man.

John xi. 25, 26.

Such are the truths revealed by God himself, which through nothing but direct revelation could have enlightened, cheered, animated, and guided the human affections and will. Man, as an immortal being, has not been left to himself. True it is, that there are many nations still in darkness, and some in the most degraded ignorance. To ask why this is so, is to ask the reasons which determine God in his purposes; we see as in a glass darkly, and the deep things of God are hidden from our eyes; but we are assured that the time will come when all nations shall know the Lord, and Christ shall reign in fulness of glory. Let us be thankful if our trust is in Christ, if he is in us the hope of glory, for "eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him."

We have sufficiently shown the necessity of a revelation to man relative to things essential to his eternal interest, but of which he could gain no knowledge by his own mental exertions. We know by internal conviction that we are immortal beings; but unguided by revelation, we shall look forward to the future with anxiety, with a sort of vague apprehension, but revelation dispels anxiety, and fills us with all "joy and peace in believing."

Dr. Abercrombie, in his work on the Intellectual Powers, says: "There is thus, in the consciousness of every man, a deep impression of continued existence. The casuist may reason against it till he bewilder himself in his own sophistries; but a voice within gives the lie to his vain speculations, and pleads with authority for a life which is to come. The sincere and humble inquirer cherishes the impression while he seeks for further light on a subject so momentous; and he thus receives with absolute conviction the truth which beams upon him from the revelation of God, that the mysterious part of his being, which thinks, and wills, and reasons, shall, indeed, survive the wreck of its mortal tenement, and is destined for immortality."

How mysterious is the union between mind and matter! how little we know of ourselves! how shallow is our deepest philosophy! We know that the mind is that part of our being which thinks and wills, reasons and remembers, but we know nothing of it except from these functions. "By means of the corporeal senses it holds intercourse with the things of the external world, and receives impressions from them, but of this connexion also we know nothing but the facts; when we attempt to speculate upon its nature and cause, we wander at once from the path of philosophical inquiry into conjectures, which are as far beyond the proper sphere as they are beyond the reach of human faculties. The object of true science on such a subject, therefore, is simply to investigate the facts or relations of phenomena, respecting the operations of mind itself, and the intercourse which it carries on with the external world."

In a philosophic point of view, all our knowledge of the world around us is referable to the operations of the mind on the impressions conveyed to it through the senses, that is, perception. Nevertheless, in point of fact, the knowledge which is acquired by an individual through perception and mental agency, as reflection, memory, etc., is but a small part of what he possesses; it is to the perception and mental labour of others that he owes the great mass of knowledge he is gifted with. Generation after generation has contributed to accumulate a store of facts, a treasury of thoughts and reflections, to which succeeding generations have added, leaving them as a legacy to generations yet to come, who will contribute in their turn to the stock, and bequeath the treasure to their successors. Thus are we enriched by the labour of others, and not altogether by our own experience.

Herein is a wide hiatus between man and the most sagacious of brutes. The brute gains all from personal experience; no generation can build upon the foundation left by a preceding generation--but man can; and it is no objection to allege, that some races remain in a savage state for ages; they possess the power, the capability, the mental constitution, which the brute does not. Besides, they do improve under favourable circumstances. What were the Anglo-Saxon marauders, our own ancestors? Savages. Is England now a savage country? What were the Celtic British in Cæsar's time? Savages. Were they savages when the Romans had held possession of the island for three hundred years? No; they had adopted the arts, the manners, the civilization of their conquerors. How this very fact of the capability of man to give and receive knowledge demonstrates his superiority in creation! It is true that the human intellect is limited, and that there are mysteries into which he cannot penetrate; nor is it needful for his welfare, his improvement, his happiness, his hopes of a joyful immortality, that he should be able to do so. Let him rely on the oracles of God. Mysteries, indeed, surround him. How fluently does he talk about matter, yet he knows nothing about it, excepting what he gains through his senses; and this knowledge is limited to certain qualities, which may be termed primary and secondary. The primary qualities of material bodies are in themselves essentials, namely, solidity and extension. We cannot conceive of matter, without an involvement of these two properties. The secondary qualities of matter are colour, texture, temperature, smell, taste, etc., properties which differ in different bodies, and which are fluctuating, changeable, uncertain. Of these, and other properties of matter, as motion, sound, lightness, or heaviness, etc., our senses are the external tests, though mind is, in reality, the discriminator.

"Our first knowledge of the existence and properties of the material world is evidently of a complex nature. It seems to arise from the combined action of several senses, conveying to us the general notion of certain essences, which are solid and extended, or possessed of those properties which characterize material things. Without this general knowledge previously acquired, our various senses, acting individually, could convey to us no definite notion of the properties of external things. A smell, that is a mere odour, for example, might be perceived by us, but would convey nothing more than the sensation simply. It could not communicate the impression of this being a property of an external body, until we had previously acquired a knowledge of the existence of that body, and had come by observation to associate the sensation with the body from which it proceeds. The same holds true of the other senses, and we are thus led at the very first step of our inquiries to a complicated process of mind, without which our mere sensations could convey to us no definite knowledge."

Abercrombie.

Here, then, we conclude. Let us give thanks and praise to that God who has made us what we are--instruments of countless strings, all in harmony, the music of which reaches the soul, and in the secret recesses of the mind is there analyzed, reflected upon, compared, and stored up as knowledge. We feel, we see, we hear, we smell, we taste, we resist; we are assured of our own individuality; we are conscious of our own existence, and we know that all around is external to our own individuality. That sense of individuality is in the mind, and we have within us the assurance of immortality. Let us look to Him, who is the Saviour from an immortality of despair, that at the day of judgment we may be found clothed in his robe of righteousness, the garment of salvation.