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find that the tread is not so firm upon it, that the toe is not so much turned out as in the right, and that a greater push is made with it. From the peculiar form of woman, and the elasticity of her step, resulting more from the motion of the ankle than of the haunches, the defect of the left foot, when it exists, is more apparent in her gait. No boy hops upon his left foot, unless he be left handed. The horseman puts the left foot in the stirrup, and springs from the right.”. We think we may conclude, that every thing being adapted, in the conveniences of life, to the right hand," as for example the direction of the worm of the screw, or of the cutting end of the augur, is not arbitrary, but is related to a natural endowment of the body. He who is left-handed is most sensible to the advantages of this adaptation, from the opening of the parlour door to the opening of a pen-knife. On the whole, the preference of the right hand is not the effect of babit, but is a natural provision, and is bestowed for a very obvious purpose : and the property does not depend on the peculiar distribution of the arteries of the arm-but the preference is given to the right foot, as well as to the right hand.
Having concluded his description of the various modifications of the hand in animals, Sir Charles next calls our attention to what he denominates, substitutes for the hand; but, confining his descriptions to the higher class of animals, he necessarily omits some of the most curious phenomena connected with this branch of inquiry. In pursuing the subject the able author takes occasion to notice certain new theories respecting the early development of animal forms, and particularly dwells on the two conditions of corporeal existence, which present between them the most remarkable contrast
. Man, in the foetal state, has a peculiar and quite distinct life, adapted to the medium in which he is fixed, and, during the interval of his confinement in this medium, preparations are going forward which are, at a given time, to make him wholly unfit for remaining there any longer, but adapt him exclusively for quite a different condition of circumstances. If, when that critical time arrived, and that the apparatus for the new residence is completed, if any delay took place in the removal, life could not continue an instant, the whole economy of the foetus being converted into a form which can operate alone in another sphere. The uniformity, the delicate care, and the certainty with which nature builds up, or rather repairs the machine that is destined for an entirely new set of functions, is so truly wonderful, so abounding in marvels, as almost to shock the understanding. During the period of nine months, when man is sustaining life as the fishes do, thie
process which, in its mature state, is to furnish him with the organs of living like an animal is constantly proceeding, and the lungs are fabricated to meet the air in which the infant is soon to be placed; and new tubes are exquisitely fasbioned and erected, before the flood gates to admit the blood are thrown open. But
Vol. III. (1833) no. Ili.
this is not all, and if, as Sir Charles Bell recommends us, we take any of the grand organs, as the heart, or the brain, and examine it through all its gradations of change in the embryo state, we shall recognise it as simple, at first, and gradually developing, and assuming the peculiarities which finally distinguish it. So that it is affirmed, and not without the support of a most curious series of observations, that the human brain, in its earlier stage, resembles that of a fish: as it is developed, it resembles more the cerebral mass of the reptile; in its increase it is like that of a bird, and slowly, and only after birth, does it assume the proper form and consistence of the human encephalon. But in all these changes to which man is subject, we nowhere see the influence of the elements, or any other cause than that it has been so predestined. And if, passing over the thousand instances which might be gathered from the intermediate parts of the chain of animal existence, we take the lowest link, and look to the metamorphosis of insects, the conclusion will be the same. For example, if we examine the larva of a winged insect, we shall see the provisions for its motion over the ground, in that condition, all admirably supplied in the arrangement of its muscles, and the distribution of its nervous system. But if, anticipating its metamorphosis, we dissect the same larva immediately before its change, we shall find a new apparatus in progress towards perfection; the muscles of its many feet are seen decaying; the nerves to each muscle are wasting; a new arrangement of muscles, with new points of attachment, directed to the wings instead of the feet, is now visible; and a new distribution of nerves is distinctly to be traced, accommodated to the parts which are now to be put in motion. Here is no budding and stretching forth under the influence of the surrounding elements, but a change operated on all the economy, and prospective, that is, in reference to a condition which the creature has not yet attained.
We have now seen what is the general nature of the structure of animals, and by what forces they are able to perform the several motions which are essential to each class respectively; and from this view we are led to consider the peculiar endowments by which the organs thus adapted to each animal are able to carry on the details of the faculties thus conferred. We shall see that the mere power of doing a vast deal with the hands and fingers, would be almost useless, and perhaps injurious, were it not for the properties of sensibility or that capability of receiving an impression from the contact of those organs with other bodies. This necessarily leads to the contemplation of the organ of touch, in which it would appear that a double sense is exercised; for, in the process of touch, we not only feel the impression of the contact, but are sensible of the exertion which the muscles make to grasp the object. The illustration of the particular manner in which the human hand is privileged
with this sensibility, constitutes an exposition of the most surprising proofs of design and of benevolence in the Almighty's dispensations to man.
Sir Charles commences by ridiculing the notions of those who imagine that nerves have that endowment of sensibility in accordance to the proportion of their fineness or coarseness; but this is not the case, and though it is true that there are nerves destined to peculiar senses, and for bestowing peculiar functions, still it is not necessary that they should differ in texture. Thus the nerve of touch distributed in every part of the skin, is utterly insensible to those impressions from without, which exercise such power on the nerves of sight or of sound. Thus whilst the nerve of the skin has no relation whatever to vision or hearing, so the nerve of the ear and the eye have no faculty of conveying a sense of touch, and consequently, of pain; and when we do experience pain in the eye, it is not the nerve devoted to vision that is implicated, but a distinct one appointed, as it were, to take cognizance of such impressions. Sir Charles Bell illustrates the state of this relation in a beautiful manner by the following statement. We should keep in mind, he says, the interesting fact, that when surgeons perform the operation of couching, the point of the needle, in passing through the outer coat of the eye, gives a sensation of pricking, which is an exercise of the nerve of touch; but when the point passes through the retina, which is the expanded nerve of vision, and forms the internal coat of the eye, the sensation that is produced is as of a spark of fire. The nerve of vision is as insensible to touch as the nerve of touch is to light.
Here we are constrained to pause for a moment, in order to con, tribute our humble efforts to secure ultimate justice to the merits of this very eminent discoverer. He has, by a series of experiments, performed more than twenty-two years ago, determined many important questions relative to the functions of the nervous system. These discoveries, at the present time, enter into the great systems of physiological science as an essential part of them; yet the credit of such successful efforts of genius and industry, is withheld from the real author of them and transferred to strangers. It is no wonder that, in other countries, either from ignorance or from design, arising out of malignant and unjustifiable jealousy, that an English, man's intellectual triumphs should be attributed to other quarters of the globe; but that such an ungenerous spirit should be acted on in the native country of the ingenious discoverer, where ignorance cannot, by possibility, be set up as an excuse for misrepresentation, a that such should be the case, would hardly be believed, did we not have the testimony of the injured party himself to the truth of the disgraceful fact.
To proceed however with the subject, which Sir Charles illustrates in so interesting a manner, we shall advert to the description which he gives of the nature and limits of the sensibility involved
in the sense of touch. Those who consider the exquisite sensibility of the surface of the body, will expect as a natural consequence, that since great pain is felt on the division by a knife of a small portion of the skin, if the knife was carried farther in, the pain would become more intense, in proportion to the depth of the wound. But the reality negatives completely such a supposition, because the skin is so supplied as to act as it were as a sentinel to the parts beneath it, so must it be unnecessary to make sentinels of those internal parts themselves. The impropriety of placing those parts in the same condition of sensibility as the external portions, would only resemble the regulation of the governor of the garrison, who should require of all the inhabitants to watch all night, as a sort of aid to the proper sentinels, if placed in their natural position on the exterior. Thus it is, that a knowledge of the truth can be made subservient to the cause of humanity; for the surgeon who has to perform an operation by incision, when he has cut through the skin, can inform his patient that the greatest pain is over. If, in the advanced stage of the operation, he has to extend the incision of the skin, it is very properly considered as a great awkwardness; and this not only, because it proves that he has miscalculated what was necessary to the correct performance of his operation, but because the patient, bearing courageously the deeper incisions, cannot sustain the renewed cutting of the skin, without giving token of severe pain.
Here there is announced the intention in the skin, and that Nature has formed it as a safeguard to the delicate textures which it contains, and by its warnings, which so well predict the approach of pain, performs the function of a defender and protector in a way which it is not in the power even of the tegument of a rhinoceros to supply. But to complete the description of the provision to which we are adverting, it is necessary that we should mention that when the knife is made to penetrate still further into the interior, so that the bones, joints, and the membranes and ligaments which cover them are exposed, the whole may be cut, pricked, or even burned with a red-hot poker, without the patient, or the animal who undergoes the operation, suffering the slightest pain. But then are those internal structures altogether so exempt from pain? Far from it, and the degree to which they have the power of feeling pain, is a striking instance of the beautiful economy of the creation. Those parts which we have mentioned as not being sensible to the pain of cutting and burning, are exquisitely sensible to a strain, a blow, a breaking, or forcible stretching of the joint. This amount of pain is, with wonderful exactness, adjusted to the nature of the injury, and that entirely with a view of informing us as to the extent of that injury, and thus we are prohibited, by the commencement of a painful sensation, from
straining our ancles for example, or our knees, by forcing them into an unnatural position. We remember once being struck with the description given us by a professional gentleman, of the scene which took place in the gallery of the theatre at the College of Surgeons, when Sir Charles Bell astonished his audience by a singular apostrophe addressed to them on this very question. The substance of this address has been recorded by himself in the following words:" Without meaning to impute to you inattention or restlessness, I may request you to observe how every one occasionally changes his positions, and shifts the pressure of the weight of his body; were you constrained to retain one position during the whole hour, you would rise stiff and lame. The sensibility of the skin is here guiding you to that, which if neglected, would be followed even by the death of the part. When a patient has been received into the hospital with paralysis of the lower part of the body, we must give especial directions to the nurse and attendants that the position of his limbs be changed at short intervals, that pillows be placed under his loins and hams, and that they be often shifted. If this be neglected, you know the consequence to be, inflammation of the parts that press upon the bed; from which comes local irritation, then fever, and mortification and death. Thus you perceive that the natural sensibility of the skin, without disturbing your train of thought, induces you to shift the body so as to permit the free circulation of the blood in the minute vessels: and that when this sensibility is wanting, the utmost attention of friends and the watchfulness of the nurse are but a poor substitute for this protection which nature is continually affording. If you suffer thus lying on a soft bed, when deprived of the sensibility of the skin, how could you encounter without it the rubs and impulses incident to an active life? You must now acknowledge that the sensibility of the skin is as much a protection to the frame generally, as the sensibility of the eyelids is to the eyes, and gives you a motive for gratitude which probably you never thought of."
In pursuing the phenomena of sensibility, Sir Charles Bell comes to the consideration of the physiology of the eye; and in the course of his review of the facts which are known respecting the faculty of vision, he takes notice of the theories which explain the impression of light on that organ. He stoutly denies the truth of the theory which represents that light is dispensed through the medium of a peculiar ether or aëriform fluid, by the vibrations or undulations which this ether makes. He says that this doctrine is at variance with anatomy, that consequently there can be no truth in it, and that its falsehood is detected by putting it at once to the test. Thus, he says, that the supporters of the theory maintain that these vibrations vary from four-hundred and fiftyeight millions of millions, to seven hundred and twenty seven millions of millions in every second; now, asks Sir Charles, suppose