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Art. VI.- An Essay on the Beneficent Distribution of the Sense
of Pain. By G. A. Rowell, Honorary Member of the Ashmolean Society and Assistant Underkeeper of the Ashmolean
Museum. Oxford, 1857. SIR IR HUMPHRY DAVY when a boy, with the defiant
constancy of youth which had as yet suffered nothing, held the opinion that pain was no evil. He was refuted by a crab who bit his toe when he was bathing, and made him roar loud enough to be heard half a mile off. If he had maintained instead, that pain was a good, his doctrine would have been unimpeachable. Unless the whole constitution of the world were altered our very existence depends upon our sensibility to suffering. An anecdote, which is quoted by Dr. Carpenter in his . Principles of Human Physiology,' from the “Journal of a Naturalist,' shows the fatal effects of a temporary suspension of this law of our nature. A drover went to sleep on a winter's evening upon the platform of a lime-kiln, with one leg resting upon the stones which had been piled up to burn through the night. That which was gentle warmth when he lay down became a consuming fire before he rose up. His foot was burnt off above the ancle, and when, roused in the morning by the man who superintended the limekiln, he put his stump, unconscious of his misfortune, to the ground, the extremity crumbled into fragments. Whether he had been lulled into torpor by the carbonic acid driven off from the limestone, or whatever else may have been the cause of his insensibility, he felt no pain, and through his very exemption from this lot of humanity expired a fortnight afterwards in Bristol hospital. Without the warning voice of pain, life would be a series of similar disasters. The crab, to the lasting detriment of chemistry, might have eaten off the future Sir Humphry's foot while he was swimming without his entertaining the slightest suspicion of the ravages which were going on. Had he survived the injuries from the crab, he would yet have been cut off in the morning of his famous career, if, when experimenting upon the gases, the terrible oppression at his chest had not warned bim to cease inhaling the carburetted hydrogen, nor, after a long struggle for life, would he have recovered to say to his alarmed assistant, “I do not think I shall die.' Without physical pain, infancy would be maimed, or perish, before experience could inform it of its dangers. Lord Kaimes advised parents to cut the fingers of their children 'cunningly' with a knife, that the little innocents might associate suffering with the glittering blade before they could do themselves a worse injury; but if no smart accompanied the wound, they would cut up their own fingers with
the same giee that they cut a stick, and burn them in the candle with the same delight that they burn a piece of paper in the fire. Without pain, we could not proportion our actions to the strength of our frame, or our exertions to its powers of endurance. In the impetuosity of youth we should strike blows that would crush our hands, and break our arms; we should take leaps that would dislocate our limbs; and no longer taught by fatigue that the muscles needed repose, we should continue our sports and our walking tours till we had worn out the living tissue with the same unconsciousness that we now wear out our coats and our shoes. The very nutriment which is the support of life would frequently prove our death. Mirabeau said of a man who was as idle as he was corpulent, that his only use was to show how far the skin would stretch without bursting. Without pain, this limit would be constantly exceeded, and epicures, experiencing no uneasy sensations, would continue their festivities until they met with the fate of the frog in the fable, who was ambitious of emulating the size of the ox. Sir Charles Bell mentions the case of a patient who had lost the sense of heat in his right hand, and who, unconscious that the cover of a pan which had fallen into the fire was burning bot, took it out and deliberately returned it to its proper place to the destruction of the skin of the palm and fingers. This of itself would be an accident of incessant occurrence if the monitor were wanting which makes us drop such materials more hastily than we pick them up. Pain is the grand preserver of existence, the sleepless sentinel that watches over our safety, and makes us both start away from the injury that is present, and guard against it carefully in the time to come.
The same Infinite Wisdom which has contrived pain for our protection has also distributed it in the manner which causes it to fulfil its defensive purposes with the least suffering to its subjects. The chapters which Sir Charles Bell devoted to this question in his work on the Hand' are alone, from their originality, and the striking evidence they afford of design, worth all the rest of the Bridgewater Treatises. The skin is the advanced guard through which every injury to the other parts must make its way. The skin, therefore, required to be the seat of a peculiar sensibility both for its own security and to impel us to flinch from the violence which would hurt the flesh beneath. Forming our notions of pain from what we feel at the surface, we imbibe the idea that the deeper the wound the more severe would be the suffering, but this, says Sir Charles Bell, is delusive, and contrary to the fact. The surgeon, he adds, who makes use of the knife, informs the patient that the worst is over when the skin is passed, and if, in the progress of the operation, it is
found necessary to extend the outer incision, the return to the skin proves far more trying than the original cut, from the contrast which it presents to the comparative insensibility of the interior. The muscle is protected not by its own tenderness, which is by no means acute, but by the tenderness of its superficial covering, which affords,' says Sir Charles, 'a more effectual defence than if our bodies were clothed with the hide of a rhinoceros.' To have endowed the delicate internal textures with an exquisite susceptibility to the gash from a knife, or a blow from a stick, would have been superfluous torture. The end is effectually attained by spreading over them a thin layer of highly sensitive skin, which is too intolerant of cuts or bruises to allow any harm to approach it, which it is in our power to avert. In addition to the protection which is thus provided against occasional dangers, the skin, by its sensibility, is essential to our existence under the hourly conditions of life. It is the skin which acts as a thermometer to tell us whether the temperature is suited to our organization, and warns us alike to shun pernicious extremes of heat and cold. It is the skin again which prompts the instinctive restlessness that preserves the entire frame from decay. A paralytic patient must be supported upon soft pillows, and his position frequently changed by the nurse, or the uninterrupted pressure upon the same surface stops the flow of the blood, of which the consequence is the speedy destruction of the part, mortification, and death. When Sir Charles Bell called the attention of his audience to this fact, in a lecture delivered before the College of Surgeons, he bid them observe how often, as they listened to him, they had moved upon their seats that they might shift the weight of their bodies, and relieve the portions which were beginning to be cramped. "Were you constrained,' he said, “ to retain one position during the whole hour you would rise stiff and lame. Even in the unconsciousness of slumber the contrivance continues to act, and, were it otherwise, sleep, instead of being nature's sweet restorer,' would derange the circulation and cripple our frames.
Not only have different parts of the system sensibilities which differ in degree, but sensibilities which differ altogether in kind, so that while both shall be acutely alive to their appropriate stimulus, one or either may be dead to the application which rouses and tortures the other. ' A man who had his finger torn off,' writes Sir Charles Bell, in his 'Animal Mechanics, to hang by the tendon only, came to a pupil of Dr. Hunter. I shall now see, said the surgeon, whether this man has any sensibility in his tendon. He laid a cord along the finger, and, blindfolding the patient, cut across the tendon. Tell me, he
asked, asked, what I have cut across ? Why, you have cut across the cord, to be sure, was the answer.' The tendon was as insensible as the string itself, Further experiments have shown that the tendons of the muscles, the ligaments which hold together the joints, the cartilages which act as a pad to the extremities of the bones where they work upon one another, feel neither cuts nor burns. But there is a very different result if they are submitted to stretching, laceration, and concussion. Then they raise the warning voice of pain, and obtuse to what might seem a more agonising species of injury, they are intolerant of the less. The reason is obvious. The skin is the fence to the inner membranes from the first class of evils, but if the skin is to have the play and power of adaptation which is essential to its functions, its suppleness would be too great to be a check upon the movements wbich affect the cartilages, the ligaments, and the tendons. These consequently are made impatient of concussion, of tearing, and of stretching, that we might not leap from heights, run with a violence, or twist our joints with a force inconsistent with the strength of the human fabric. The pain of a sprained ancle shows how sufficient is the punishment to put a check upon any excesses of the kind. Exchange the sensibilities, confer upon the membranes which are interposed between the joints, or which tie them together, the same feelings both in kind and degree which belong to the skin, the common movements of the body, or even the weight of one foot upon another, would have been attended, says Sir Charles Bell, with as much suffering as we experience when we walk upon an inflamed limb.
Paley applauds the contrivance by which everything we eat and drink is made to glide on its road to the gullet, over the entrance of the wind-pipe without falling into it. A little moveable lid, the epiglottis, which is lifted up when we breathe, is pressed down upon the chink of the air-passage by the weight of the food and the action of the muscles in swallowing it. Neither solids nor liquids, in short, can pass without shutting down the trapdoor as they proceed. But this is only a part of the safe-guard. The slit at the top of the wind-pipe, which never closes entirely while we breathe, is endued with an acute sensibility to the slightest particle of matter. The least thing which touches the margin of the aperture causes its sides to come firmly together, and the intruding body is stopped at the inlet. It is stopped, but, unless removed, must drop at the next inspiration into the lungs. To effect its expulsion the sensibility of the rim at the top of the wind-pipe actually puts into vehement action a whole class of muscles placed lower than its bottom, and which, com
pressing pressing the chest over which they are distributed, drives out the air with a force that sweeps the offending substance before it. The convulsive coughing which arises when we are choked is the energetic effort of nature for our relief when anything chances to have evaded the protective epiglottis. Yet this property, to which we are constantly owing our lives, is confined to a single spot in the throat. It does not, as Sir Charles Bell affirms, belong to the rest of the wind-pipe, but is limited to the orifice, where alone it is needed. Admirable too, it is to observe, that while thus sensitive to the most insignificant atom, it bears without resentment the atmospheric currents which are incessantly passing to and fro over its irritable lips. It rejects,'
• says Paley, the touch of a crumb of bread, or a drop of water, with a spasm which convulses the whole frame; yet, left to itself and its proper office, the intromission of air alone, nothing can be so quiet. It does not even make itself felt; a man does not know that he has a trachea. This capacity of perceiving with such acuteness, this impatience of offence, yet perfect rest and ease when let alone, are properties, one would have thought, not likely to reside in the same subject. It is to the junction, however, of these almost inconsistent qualities, in this, as well as in some other delicate parts of the body, that we owe our safety and our comfort-our safety to their sensibility, our comfort to their repose.
Another of the examples adduced by Bell is that of the heart. The famous Dr. Harvey examined, at the request of Charles I., a nobleman of the Montgomery family who, in consequence of an abscess, had a fistulous opening into the chest, through which the heart could be seen and handled. The great physiologist was astonished to find it insensible. “I then brought him,' he says, ' to the king that he might behold and touch so extraordinary a thing, and that he might perceive, as I did, that unless when we touched the outer skin, or when he saw our fingers in the cavity, this young nobleman knew not that we touched the heart.' Yet it is to the heart that we refer our joys, our sorrows, and our affections; we speak of a good-hearted and a bad-hearted, a hard-hearted and a kind-hearted, a true-hearted and a heartless man. Shielded from physical violence by an outwork of bones, it is not invested with sensations which could have contributed nothing to its preservation, but while it can be grasped with the fingers and give no intimation of the fact to its possessor it unmistakeably responds to the varied emotions of the mind, and by the general consent of mankind is pronounced the seat of our pleasures, griefs, sympathies, hatreds, and love. Persons have frequently dropped down dead from the vehemence with which