« AnteriorContinuar »
from too great a volume of blood cir- I shall not hear a word of what is culating in the vessels ramifying over spoken ; and the same effect will be it, or from blood effused upon its sur- produced, if I abstract my attention face, apoplexy, paralysis, and death, totally from every thing around me, are the results.
and fix my thoughts, as it were, on In advancing to direct our inquiries vacancy, assuming a state of mental respecting the impressions received abstraction, called reverie. through that power of the nerves We have already previously obserytermed percipient sensibility, we shall ed, that it is through the medium of observe, in limine, that a distinction sensation we become aware of our is to be drawn between the vividness own existence, and the existence of of sensation, and the accuracy with surrounding objects. The sensations which the mind judges of objects by by which we acquire this knowledge, sensation, or, as it is termed, accuracy various and complex as they may be, of feeling.
have been, by some writers, referred The first time that any stimulus ultimately to two classes, viz. pleasure acts upon the senses, it in general and pain; and although numberless produces a vivid sensation ; but the sensations, which we perpetually expeliveliness and vividness of impressions rience, appear to excite in us neither become diminished in proportion as the one nor the other, we must not the action of such stimulus on the too hastily conclude that this arrangesenses is repeated; and by these ment is without foundation ; for let us means, the sensation may be at length reflect on the modification which haalmost annihilated; which effect is bit produces-how soon even pain beproduced in common language by ha- comes less irksome, and pleasure a bit. Sensations can, in some degree, matter of indifference; and remember be rendered, at will, more vivid and how those circumstances, which on intense ; and the Author of our frame their first occurrence produced feelings has also endowed us with the faculty of delight, are now little noticed by of moderating and diminishing them. their continuance or frequency; at Thus, if we wish to render a sensa- the same time considering, also, how tion as impressive as possible, we dis- in childhood, when the system is as pose the organs of sensation in the yet new to the crowd of sensations most advantageous manner,-we di- which are about to call forth the exrect the whole nervous sensibility to ercise of untried faculties, no occur. one particular part,—we receive but a rence is indifferent, but a cause either small number of impressions at the of pleasure or of pain, and we shall be same time, applying all our attention more ready to yield our assent. Beto them :-hence, a great difference is sides, too, it must be allowed, that alestablished between merely seeing, though numberless sensations (and it and regarding attentively; between is wisely so ordered by Providence) hearing, and listening. On the other do not draw us from our duties by the hand, when we wish to moderate the pleasure or pain they communicate, a vivacity of any sensation, we either slight or unusual increase of any of generalize (if the term be allowed) such sensations immediately deterthe nervous sensibility, or direct it in- mines it decisively to the one state of tently to another object ;-for instance, feeling or the other. if I happen to be in a room where It is by a wise and merciful arconversation is passing, to which I rangement, that without any process wish not to listen ; if I direct, by a of reasoning, without the aid of resort of mental force, my attention to flection, we instinctively withdraw some object, as the examination of a from whatever inflicts pain, and are painting, or engage myself in thinking so led to avoid at once whatever milion a subject which requires a more tates against the safety and preservathan common exertion of the mind,- tion of our animal frame ;-and hence
arises a natural love of pleasure, which, acquired; for it has been observed were we like the brutes that perish, that a more than usual development of it would be well to indulge in; but one is generally attended by a deteriwhich reason and religion teach us to oration of the rest; and that when enjoy with moderation, or forego alto- one is lost, some of the others are rengether, when (as is too often the dered more acute. Thus, in the case) such indulgence would render blind, we often see an extreme livelius useless and unworthy members of ness and vigor of feeling, so that by society.
the touch alone many are able to disWe have already intimated, that tinguish even the varieties of color : sensation supposes a common sensori- this faculty, of course, is gained only um, to which every impression must by habit and frequent practice ; but be referred. Hence certain animals were the organs of all the senses perof the lowest rank, we may conclude fect, such a result would never arise, with reason, feel nothing ; or at least, even from the most assiduous applicanothing analogous to what we call tion. pain or pleasure ; and here again we The different senses, as they are see proofs of wisdom. These animals termed, although possessed by all the are all incapable of avoiding injuries, animals of the higher class, that is, by to which they are continually liable; mammalia and birds, are not disposed hence, did they feel, their existence among them in the same degree; nor must of necessity be one of unavoida- even among all the tribes of which the ble suffering ; but such is their organi- human race is composed ; since it apzation, and their tenacity of life, that pears, that different nations are nuore they are not only divided into parts or less gifted in various points, accordwith impunity to themselves, but in ing to their necessities, habits, and many animals the parts become dis- modes of life. For instance, man, in tinct existences.
civilized society, endowed with vision With respect to accuracy of feeling, sufficiently clear and distinct, possess(and in this expression we would in- es not this faculty in so powerful and clude all the senses,) we have to re- extensive a degree as the Arab or mark, that it is acquired only by American Indian ; but over the most practice and experience ; and hence, gifted in this respect of the human the eye is enabled to judge correctly race, many animals, especially of the of size and distance, as well as of the feathered tribe, have aniazing advanminute gradations of color. For ex- tage. The eagle, towering above the ample : to an infant, or to one born clouds beyond our sight, or seen only blind, but whose sight has been lately as a dark speck in the sky, surveys the restored, distant objects seem as near wide extent of the mountain-range or as those that are so ; for a knowledge plain below, and marks his prey at an of perspective, of relative size and almost incredible distance. The proportion, is yet to be gained ;-by sense of smell in the dog, the vulture, degrees, however, the eye begins to and many other aniinals, is extremely discriminate with accuracy, and at acute and discerning ; for it is by the length the sense is perfect. It is exercise of this faculty, principally, thus, also, with regard to the ear : it that they are enabled to procure their is, for the most part, practice alone, food. But to man, having no need of which enables us to distinguish, by this, and in every climate depending the medium of this organ, between on means far different for his support, discord and harmony, and every modu- Nature, bountiful, but not lavish, has lation of sound ; and by practice, the denied a gift, which, if possessed in sense of taste likewise becomes re- so great a degree, would be of no fined and discriminating. An equally utility, if not an actual disadvantage. complete perfection of all the senses . In the sense of hearing, as it reat once, seems almost impossible to be spects distance, although man is infc
rior to many animals, none possess an higher, or in so high a degree of perfecear so highly discriminating and sus- tion as man, in whom we know this ceptible ; nor does it appear that in sense to be capable of such modificaother animals this delicacy (as far as tion and refinement. The class of they do possess it) can be corrected and birds and fishes are in this point, improved ;--among mankind, however, beyond dispute, considerably below we must allow considerable difference man and the mammalia ; and yet to exist. Some individuals, for in- these are also able to discriminate stance, are susceptible, from birth, of in the choice of their food, being a peculiarly pleasurable emotion from guided merely by instinct. Hence, certain successions of modulated as it appears that it is hy instinct that sounds, termed music ; and the indi- the lower animals are guided in the viduals thus deriving pleasure, are selection of food, refusing or acceptsaid to have a musical ear. To others, ing, according as it dictates, and not on the contrary, music affords no liking or disliking from a refined delipleasure ; and some can scarcely dis- cacy of taste, there is no reason why tinguish one tune from another. Still, this endowment, in a degree equal to however, a taste for music may be ac- what man enjoys, should be assigned quired, provided the ear be capable of to them, as some physiologists hare discriminating well between each va- done. riety and modulation of tone, or, in In the sense of feeling, a property other words, be, as it is commonly diffused so universally throughout all termed, nice. I think we must allow, animated nature, man stands supremethat a nice and a musical ear are dis- ly preëminent. To every part of his tinct from each other; for (though it frame this power belonys, but the hand commonly may be so it does not alone can distinguish and appreciate; follow that an ear, possessing great it is the regulator of the sight, and discrimination between sounds, should corrects its errors and mistakes,-it derive much pleasure from them ; yet informs us of the size, figure, consiststill, by such an car, a musical taste ence, dryness, or humidity, and to a may certainly he acquired.
certain degree of the temperature, of With regard to other animals, al- bodies; and is, besides, capable of a though some are delighted by melody, degree of perfection scarcely credible. or a succession of simple sounds, yet But among the brute creation delicacy it does not appear that they derive of touch is not necessary; nor is it that peculiar gratification from harmo- indeed compatible with their mode of ny which man so universally enjoys, existence. Yet if we survey the anior at least may, by cultivation. mal world, we shall find that each,
The sense of taste, we may reason- according to the intellectual powers ably conclude, man possesses in a (we crave a license for the expression) degree decidedly superior to that of of the class or order to which it beall inferior animals ; for although he longs, possesses this sense, refined to is certainly unable by this faculty to a greater or less extent; for it would distinguish poisonous or noxious sub- seem, that between the powers of stances, from those of a contrary na- judgment and reflection, and delicacy ture, which we see exemplified in of touch, there exists a considerable many animals, especially of the herbi- connexion; as if the latter was given vorous class, by their rejecting those to inform, aid, and direct these mental plants whose effects are known to be operations, and bring more accurate injurious to them; yet as this faculty information upon objects, of which is evidently the result of an instinctive juster ideas will thus be gained, and perception, and therefore unconnected on which the mind may thus be niore with delicacy of taste, it will hardly advantageously exercised. But as be allowed probable, that, as it is un- none approach mankind in mental necessary, they should possess it in a powers, so none in this respect also are equally endowed. Indeed, if we gree of motion enjoyed by the arm, (as except the ape tribe, whose anatomi- we venture to call it,) and consequently, cal configuration approaches closely to of an organ of greater or less similitude that of man, we do not find any orders to the human hand, as it regards use of beings endowed with, and using the and sensibility. For example : in the hand, like man, as the grand organ of horse, cow, &c. the motion of the foretouch, and capable of such exquisite limbs is confined, being merely proimprovement.
gressive ;-in these the clavicle is But among the assembly of lower wanting, and their foot bears not the animals, the elephant stands conspicu- slightest resemblance to the hand, eious, unique, and remarkable for the ther in configuration or sensibility. peculiar organ of touch with which But, on the contrary, in the ape we nature has invested him. He has not find a perfect clavicle, and an arm and a hand, but his proboscis, with what hand differing but in a few points may well be called a finger at its ex- from the human, and enjoying perfect tremity, and which is sensitive and freedom of motion. In the squirrel, pliable, gives him a vast and decided the mouse, and others, the clavicle, advantage. He is thus enabled, not though existing, is imperfect; the only to gather his food, which he does hand bears a much more distant reby means of this instrument, and con- semblance to the human; the power Fey it to his mouth, but to pick up of rotatory motion in the arm is more and examine substances extremely circumscribed; the nails are formed minute.
for seizing and retaining, and the senBut as it respects the brute creation sibility of the hand is inconsiderable. in general, although many animals, as Below these animals, are the feline the squirrel, the cat, and others, make tribe ;-—the cat, for instance, has a a considerable use of the arm, if it still less perfect clavicle, and the mo
may be so called, and are certainly tion of the fore-limbs is still more lipetits furnished by its means with the sense mited, while the foot or paw, (for here
of touch to a limited degree, still we it cannot be called band,) incapable do not find this member terminating in of holding or grasping objects, as in a hand-Hexible, and capable of such the squirrel, is furnished with nails, extensive power and variety of mo- destined to seize and lacerate. Thus tion—so exquisitely sensible, also, as in do we find, among the inferior mamman. We find no distinct and accu- malia, according to the perfection or rately formed fingers, covered with a absence of the clavicle, a nearer or soft cushion, composed almost entire- more distant approach to the human ly of one mass of nervous fibres, and arm and hand in shape, sensibility, a network of vessels. On the contra- and power of motion. ry, in all animals in which even an The sense of touch, properly so approach to the human hand is disco- called, is enjoyed universally by the vered, we find this organ ill-shaped, skin or integument surrounding and or indistinctly divided,—the fingers enveloping the frame; but, as we are not tapering, nor protected by a have intimated, not by every part of broad expanded nail ;--this is con- it in the same accurate degree of perstructed in such, for retaining or lace- fection ; for as this depends, in a rating, rather than for serving as a great measure, on use and habit, (supdefence to the multitude of nerves, posing also a nicer organization,) with which the fingers in man are so where it is the most exercised in a abundantly supplied.
way accordant with nature, it will, of It may not, perhaps, be foreign in course, be the most perfect. this place to remark, that the presence, The term skin is employed to deabsence, and relative perfection of the signate a texture, composed of three clavicle, or collar-bone, in animals, fur- membranes, differing from each other nishes a characteristic mark of the de- in use and composition. These are the
cutis vera, or true skin; the rete mu. or cuticle. This is a thin, transpacosum, or mucous web; and the epi- rent, and insensible membrane, being dermis, external membrane, or cuticle supplied neither with nerves nor vesThe cutis vera is a texture formed al- sels of any description. If minutely most entirely of vessels and nerves,- examined, it is found to be abundantly at least they are distributed most perforated in every part by the orifices abundantly throughout its whole com- of the exhalants and absorbents, composition. Here, numerous minute ar- monly called the pores; but besides teries terminate in erhalants,-here preventing evaporation, the use of the the absorbent system commences, and epidermis is also to cover the nervous the nervous filaments end. If this mem- papillæ, and thereby moderate the brane be accurately exainined, mul sensation, too vivid, and amounting to titudes of small papillæ or eminences pain, which the actual contact of even are found arising from its surface, the most delicate bodies would prodisposed in regular order, but varying duce. When removed, as by blisters in different parts in shape and magni- or scalding water, the epidermis tude : these are the pulpous extremi- is quickly reproduced, but by what ties of the nerves, thus elevated, for precise process, is still doubtful.the purpose of increasing their power Some animals shed the cuticle periodiof perception, and surrounded by a cally, entire like a sheath, as serweb of the most exquisite fineness. pents; from other animals, it is thrown In those parts where the sense of touch off in the form of scales or dust, a new is most exercised and in the highest cuticle being previously prepared. perfection, as in the hand and tips of Besides these natural changes, it unthe fingers, these papillæ are the most dergoes others, as thickening from distinct and elevated. Over this cutis pressure, which we may observe in vera is spread the rete mucosum, so the palms of the hands, or soles of the called from its gelatinous consistence feet, sometimes assuming the consistand net-like structure, being perforat- ence of horn. ed universally by the exhalant vessels, The cuticle offers a variety of apabsorbents, and nervous papillæ. The pearances in different animals, from a principal use of this delicate web texture soft and delicate, and even seems to be, to preserve the nerves in like mucus in some aquatic animals, a state of moisture, favorable to their to scales, shells, and plates, constitutsensibility and action.
ing a natural armor. In all climates the color of the rete These are the membranes composmucosum is found to vary ; but from ing the skin ; but besides this, there what cause it is difficult perhaps to is universally or partially between it determine. In the negro it is black; and the muscles, in most animals, in the American, copper-colored ; in what is called the cellular membrane. the Asiatic, tawny or olive ; and in the This is a tissue composed of memEuropean, from a darkness almost branous cells, formed by the crossing equal to the negro, to a white; in of the membranes in all directions, fact, it would seem, that as we recede and serving as the receptacle for the from the temperate climes to the tro- fat. Its use appears to be to weaken pic, or to the pole, the skin gradually the impressions of external injuries, assumes a darker hue, till, under the and protect against the effect of equator at least, it becomes complete- changes of temperature in the surly black.
rounding element; but especially to The rete mucosum we have stated serve as a magazine for the deposition to be gelatinous; and to prevent the of the superabundant nutriment which evaporation of moisture, and preserve the system is supplied with, to be reit in its natural state of humidity, it absorbed as the wants of the body is entirely covered by the epidermis, may require.