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The excretory function of the skin is of such paramount importance to health that we ought at all times to direct our attention to the means of securing its being duly performed; for if the matters that ought to be thrown out of the body by the pores of the skin are retained, they invariably prove injuri
When speaking of the excrementitious matter of the skin, we do not mean the sensible moisture which is poured out in hot weather, or when the body is heated by exercise ; but a matter which is too subtile for the senses to take cognizance of - which is continually passing off from every part of the body, and which has been called the insensible perspiration. This insensible perspiration is the true excretion of the skin.
A suppression of the insensible perspiration is a prevailing symptom in almost all diseases. It is the sole cause of many fevers. Very many chronic diseases have no other cause. In warm weather, and particularly in hot climates, the functions of the skin being prodigiously increased, all the consequences of interrupting them are proportionably dangerous.
Besides the function of perspiration, the skin has, in common with every other surface of the body, a process, by means of appropriate vessels, of absorbing or taking up, and conveying into the blood vessels, any thing that may be in contact with it; it is also the part on which the organ of feeling or touch is distributed.
The skin is supplied with glands, which provide an oily matter that renders it impervious to water, and thus secures the evaporation of the sensible perspiration. Were this oily matter deficient, the skin would become sodden, as is the case when it has been removed, a fact to be observed in the hands of washerwomen, when it is destroyed by the solvent powers of the soap. The hair serves as so many capillary tubes to conduct the perspired fluid from the skin.
The three powers of the skin - perspiration, absorption, and feeling, are so dependent on each other, that it is impossible for one to be deranged without the other two being also disordered. For if a man be exposed to a frosty atmosphere, in a state of inactivity, or without sufficient clothing, till his limbs become stiff and his skin insensible, the vessels that excite the perspiration and the absorbent vessels partake of the torpor that has seized on the nerves of feeling, nor will they regain their lost activity till the sensibility be completely restored. The danger of suddenly attempting to restore sensibility to frozen parts is well known. If the addition of warmth be not very gradual, the vitality of the part will be destroyed.
This consideration of the functions of the skin will at once
point out the necessity of an especial attention, in a fickle climate, to the subject of clothing. Every one's experience must have shown him how extremely capricious the weather is in this country. Our experience of this great inconstancy in the temperature of the air ought to have instructed us how to secure ourselves from its effects.
The chief end proposed by clothing ought to be protection from the cold; and it never can be too deeply impressed on the mind (especially of those who have the care of children), that a degree of cold that amounts to shivering cannot be felt, under any circumstances, without injury to the health ; and that the strongest constitution cannot resist the benumbing influence of a sensation of cold constantly present, even though it be so moderate as not to occasion immediate complaint, or to induce the sufferer to seek protection from it. This degree of cold often lays the foundation of the whole host of chronic diseases, foremost amongst which are found scrofula and consumption.
Persons engaged in sedentary employments must be almost constantly under the influence of this degree of cold, unless the apartment in which they work is heated to a degree that subjects them, on leaving it, to all the dangers of a sudden transition, as it were, from summer to winter. The inactivity to which such persons are condemned, by weakening the body, renders it incapable of maintaining the degree of warmth necessary to comfort, without additional clothing or fire. Under such circumstances, a sufficient quantity of clothing of a proper quality, with the apartment moderately warmed and well ventilated, ought to be preferred, for keeping up the requisite degree of warmth, to any means of heating the air of the room so much as to render any increase of clothing unnecessary. To heat the air of an apartment much above the ordinary temperature of the atmosphere, we must shut out the external air; the air also becomes extremely rarefied and dry, which circumstances make it doubly dangerous to pass from it to the cold, raw, external air.
But in leaving a moderately well warmed room, if properly clothed, the change is not felt; and the full advantage of exercise is derived from any opportunity of taking it that may occur.
The only kind of dress that can afford the protection required by the changes of temperature to which high northern climates are liable, is woollen. Nor will it be of much avail that woollen be worn, unless so much of it be worn, and it be so worn as effectually to keep out the cold. Those who would receive the advantage which the wearing woollen is capable of affording,
must wear it next the skin ; for it is in this situation only that its health-preserving power can be felt. The great advantages of Woollen cloth are briefly these ; the readiness with which it allows the escape of the matter of perspiration through its texture - its
power of preserving the sensation of warmth to the skin under all circumstances the difficulty there is in making it thoroughly wet the slowness with which it conducts heat - the softness, lightness, and pliancy of its texture.
Cotton cloth, though it differs but little from linen, approaches nearer to the nature of woollen, and on that account must be esteemed as the next best substance of which clothing may be made.
Silk is the next in point of excellence, but it is very inferior to cotton in every respect.
Linen possesses the contrary of most of the properties enumerated as excellences in woollen. It retains the matter of perspiration in its texture, and speedily becomes imbued with it; it gives an unpleasant sensation of cold to the skin; - it is very readily saturated with moisture, and it conducts heat too rapidly. It is, indeed, the worst of all the substances in use, being the least qualified to answer the purposes of clothing.
There are several prevailing errors in the mode of adapting clothes to the figure of the body, particularly amongst females. Clothes should be so made as to allow the body the full exercise of all its motions. The neglect of this precaution is productive of more mischief than is generally believed. The misery and suffering arising from it begin while we are yet in the cradle. When they have escaped from the nurses' hands, boys are left to nature. Girls have for awhile the same chance as boys in a freedom from bandages of all kinds; but as they approach to womanhood, they are again put into trammels in the forms of stays. The bad consequences of the pressure of stays are not immediately obvious, but they are not the less certain on that account; the girl writhes and twists to avoid the pinching, which must necessarily attend the commencement of wearing stays tightly laced; the posture in which she finds ease is the one in which she will constantly be, until at last she will not be comfortable in any other, even when she is freed from the pressure that originally obliged her to adopt it. In this way most of the deformities to which young people are subject originate; and, unfortunately, it is not often that they are perceived until they have become considerable, and have existed too long to admit of remedy.
We are all thoroughly aware of the necessity of breathing; and the agreeable freshness and reviving influence of the pure morning air must convince us that the breathing a pure atinosphere is conducive to health ; yet we as carefully exclude the air from our houses as if its approach were noxious. Intending to shut out the inclemencies of the weather only, in our care to guard ourselves from the external air, we hinder that renewal of the atmosphere which is necessary to prevent its becoming stagnant and unfit to support animal life.
Few persons are aware how very necessary a thorough ventilation is to the preservation of health. We preserve life without food for a considerable time, but keep us without air for a very few minutes, and we cease to exist. It is not enough that we have air, we must have fresh air; for the principle by which life is supported is taken from the air during the act of breathing. One fourth only of the atmosphere is capable of supporting life; the remainder serves to dilute the pure vital air, and render it more fit to be respired. A full grown man takes into his lungs nearly a pint of air each time he breathes; and when at rest, he makes about twenty inspirations in a minute. In the lungs, by an appropriate apparatus, the air is exposed to the action of the blood, which changes its purer part, the vital air (oxygen gas), into fixed air (carbonic acid gas), which is not only unfit to support animal life, but is absolutely destructive of it. An admirable provision of the great Author of nature is here visible, to prevent this exhausted and now poisonous air from being breathed a second time; while in the lungs, the air receives so much heat as makes it specifically lighter than the pure atmosphere; it consequently rises above our heads during the short pause between throwing out the breath and drawing it in again, and thus secures to us a pure draught. By the care we take to shut out the external air from our houses, we prevent the escape of the deteriorated air, and condemn ourselves to breathe again and again the same contaminated, unrefreshing atmosphere.
Who that has ever felt the refreshing effects of the morning air, can wonder at the lassitude and disease that follow the continued breathing of the pestiferous atmosphere of crowded or ill-ventilated apartments? It is only necessary to observe the
countenance of those who inhabit close rooms and houses, the squalid hue of their skins, their sunken eyes, and their languid movements, to be sensible of the bad effects of shutting out the external air.
Besides the contamination of the air from being breathed, there are other matters which tend to depreciate its purity; these are the effluvia constantly passing off from the surface of animal bodies, and the combustion of candles and other burning substances. On going into a bed-room in a morning, soon after the occupant has left his bed, though he be in perfect health and habitually cleanly in his person, the sense of smelling never fails to be offended with the odor of animal effluvia with which the atnosphere is charged. There is another case, perhaps, still more striking, when a person fresh from the morning air enters a coach in which several persons have been close-stowed during a long night. He who has once made the experiment will never voluntarily repeat it. The simple expedient for keeping down both windows but a single half-inch would prevent many of the colds, and even fevers, which this injurious mode of travelling often produces. If, under such circumstances, the air is vitiated, how much more injuriously must its quality be depreciated when several persons are confined to one room, where there is an utter neglect of cleanliness ; in which cooking, washing, and all other domestic affairs are necessarily performed; where the windows are immovable, and the door is never opened but while some one is passing through it!
It may be taken as a wholesome general rule, that whatever produces a disagreeable impression on the sense of smelling is unfavorable to health. That sense was doubtless intended to guard us against the dangers to which we are liable from vitiation of the atmosphere. If we have, by the same means, a high sense of gratification from other objects, it ought to excite our admiration of the beneficence of the Deity in thus making our senses serve the double purpose of affording us pleasure and security; for the latter end might just as effectually have been answered by our being only susceptible of painful impressions.
To keep the atmosphere of our houses free from contamination, it is not sufficient that we secure a frequent renewal of the air all matters which can injure its purity must be carefully removed.
Flowers in water and living plants in pots greatly injure the purity of the air during the night, by giving out large quantities of an air (carbonic acid) similar to that which is separated