Part 2 (1/2)
The capacity of the lungs varies considerably in different individuals.[3]
On a general average, they may be said to contain about 280 cubic inches, or nearly five quarts of air. By each inspiration about forty cubic inches of air are received into the lungs, and at each expiration the same quant.i.ty is discharged. If, therefore, we calculate that twenty respirations take place in a minute, and forty cubic inches to be the amount of each inspiration, it follows, that in one minute, we inhale 800 cubic inches; in an hour, the quant.i.ty of air inspired will be 48,000 cubic inches; and in the twenty-four hours, it will amount to 1,152,000 cubic inches. This quant.i.ty of air will almost fill 78 wine hogsheads, and would weigh nearly 53 pounds. From this admirable provision of nature, by which the blood is made to pa.s.s in review, as it were, of this immense quant.i.ty of air, and over so extensive a surface, it seems obvious, that these two fluids are destined to exert some very important influence on each other; and it has been proved, by a very decisive experiment of Dr.
Priestley's, that the extremely thin membrane, which is alone interposed, does not prevent the exercise of the chemical affinity which prevails between the air which is received in the lungs, and the blood which is incessantly circulating through them. It must surely, therefore, be of the first importance to health, that the fluid of which we hourly inhale, at least, three hogsheads, should not be contaminated by the suspension of noxious effluvia.
The purity of the atmosphere may be impaired either by the operation of what some denominate natural causes, or by the influence of circ.u.mstances resulting from our social condition. Its chemical const.i.tution is changed by respiration; the vital principle is destroyed, and its place supplied by a highly poisonous gas.
The emanations from the surface of our bodies contribute, in a still greater degree, to vitiate the atmosphere, and to render it less fit for the healthful support of life. Many of the organs which compose our wonderfully complicated frame are engaged in discharging the const.i.tuent parts of our bodies, which, by the exercise of the various animal functions, are become useless, and, if retained, would become noxious.
Physiologists have inst.i.tuted a variety of experiments, to ascertain the amount of the exhalations from the surface of the body. Sanctorius, an eminent Italian physician, from a series of experiments performed during a period of thirty years, estimates it as greater than the aggregate of all our other discharges. From his calculations it would appear, that if we take of liquid and solid food eight pounds in the twenty-four hours, that five pounds are discharged by perspiration alone, within that period; and of this, the greater part is what has been denominated insensible perspiration, from its not being cognizable to the senses. We may estimate the discharge from the surface of the body, by sensible and insensible perspiration, as from half an ounce to four ounces per hour.
The exhalations from the lungs and the skin are, to a certain extent, offensive even in the most healthy individuals; but when proceeding from those labouring under disease, they are in a state very little removed from putrefaction.
Animal miasmata, like all other poison, become more active in proportion to the quant.i.ty which we imbibe. When, therefore, the air is stagnant, and when many individuals contribute their respective supplies of effluvia to vitiate it, the atmosphere necessarily becomes satured with the poison; and when inhaled, conveys it in a more virulent and concentrated state to the extensive and delicate surface of the lungs.
The collection of animal effluvia in confined places, is the source of the generation and diffusion of febrile infection: but when the miasmata are respired, in a diluted state, the ill effects which they produce, though slower in their operation, are equally certain. They, to a certain extent, pollute the fountain of life, and ultimately break down the vigour of the most robust frame; impairing the action of the digestive organs, engendering the whole train of nervous disorders, and rendering the body more susceptible of disease.
The lungs and the skin may equally become the means of introducing poisonous or infectious matter into the const.i.tution. The venom of a poisonous animal, the matter of small-pox, and many other contagions, produce their influence through the medium of the skin. Infectious diseases are communicated by the reception of air in our lungs, impregnated with contagious matter. The influence of the constant respiration of air in any degree impure, is fully evinced in the pallid countenances and languid frames of those who live in confined and ill-ventilated places; and the health of all cla.s.ses of society suffers precisely in proportion to the susceptibility of their const.i.tutions, and according to the greater or less impurities of the air which they habitually respire.
Of the offensive nature of animal effluvia, the senses of every one who enters a crowded a.s.sembly, must immediately convince him. When, therefore, we reflect on the state of the air which we breathe in churches, theatres, schools, and all crowded a.s.semblies; and when we consider the amount of the exhalations emitted by each individual, and the very offensive nature of those emitted by many; and when, on the other hand, we take into consideration the importance of air to life, and the great quant.i.ty of this fluid which we daily respire, we must be naturally led to the adoption of such measures as would secure in our private dwellings, as well as in our public buildings, a full and unintermitting supply of fresh atmospheric air.
It is curious to observe the influence of habit, in reconciling us to many practices which would otherwise be considered in the highest degree offensive. Thus, while, with a fastidious delicacy, we avoid drinking from a cup which has been already pressed to the lips of our friends, we feel no hesitation in receiving into our lungs an atmosphere contaminated by the breath and exhalations of every promiscuous a.s.sembly.
”Were once the energy of air deny'd, The heart would cease to pour its purple tide The purple tide forget its wonted play, Nor back again pursue its curious way.”
The next Subject of Curiosity we shall consider, is, THE HAIR OF THE HEAD.
If we consider the curious structure, and different uses of the hair of our heads, we shall find them very well worth our attention, and discover in them proofs of the wisdom and power of G.o.d.
In each entire hair we perceive with the naked eye, an oblong slender filament, and a bulb at the extremity thicker and more transparent than the rest of the hair. The filament forms the body of the hair, and the bulb the root. The large hairs have their root, and even part of the filament, enclosed in a small membraneous vessel or capsule. The size of this sheath is proportionate to the size of the root, being always rather larger, that the root may not be too much confined, and that some s.p.a.ce may remain between it and the capsule. The root or bulb has two parts, the one external, the other internal. The external is a pellicle composed of small laminae; the internal is a glutinous fluid, in which some fibres are united; it is the marrow of the root. From the external part of the bulb proceed five, and sometimes, though rarely, six small white threads, very delicate and transparent, and often twice as long as the root. Besides these threads, small knots are seen rising in different places; they are viscous, and easily dissolved by heat. From the interior part of the bulb proceeds the body of the hair, composed of three parts; the external sheath, the interior tubes, and the marrow.
When the hair has arrived at the pore of the skin through which it is to pa.s.s, it is strongly enveloped by the pellicle of the root, which forms here a very small tube. The hair then pushes the cuticle before it, and makes of it an external sheath, which defends it at the time when it is still very soft. The rest of the covering of the hair, is a peculiar substance, and particularly transparent at the point. In a young hair this sheath is very soft, but in time becomes so hard and elastic, that it springs back with some noise when it is cut. It preserves the hair a long time. Immediately beneath the sheath are several small fibres, which extend themselves along the hair from the root to the extremity. These are united amongst themselves, and with the sheath that is common to them, by several elastic threads; and these bundles of fibres form together a tube filled with two substances; the one fluid, the other solid; and these const.i.tute the marrow of the hair.
The wonders of creating power are seen in every thing, even in the hair that adorns our surface.
All are but parts of one stupendous whole, Whose body Nature is, and G.o.d the soul.
That, chang'd thro' all, and yet in all the same; Great in the earth, as in th' ethereal frame; Warms in the sun, refreshes in the breeze, Glows in the stars, and blossoms in the trees, Lives thro' all life, extends thro' all extent, Spreads undivided, operates unspent; Breathes in our soul, informs our mortal part, As full, as perfect, in a hair as heart; As full, as perfect, in vile Man that mourns, As the rapt seraph that adores and burns: To him no high, no low, no great, no small; He fills, he bounds, connects, and equals all.
_Pope._
We shall now introduce to our readers some _Ancient and Modern Opinions respecting the Hair_.
The ancients held the hair a sort of excrement, fed only with excrement.i.tious matters, and no proper part of a living body. They supposed it generated of the fuliginous parts of the blood, exhaled by the heat of the body to the surface, and then condensed in pa.s.sing through the pores. Their chief reasons were, that the hair being cut, will grow again, even in extreme old age, and when life is very low; that in hectic and consumptive people, where the rest of the body is continually emaciating, the hair thrives; nay, that it will even grow again in dead carcases. They added, that hair does not feed and grow like the other parts, by introsusception, i. e. by a juice circulating within it, but, like the nails, by juxtaposition. But the moderns are agreed, that every hair properly and truly lives, and receives nutriment to fill it, like the other parts; which they prove hence, that the roots do not turn grey in aged persons sooner than the extremities, but the whole changes colour at once; which shews that there is a direct communication, and that all the parts are affected alike. In strict propriety, however, it must be allowed, that the life and growth of hairs is of a different kind from that of the rest of the body, and is not immediately derived therefrom, or reciprocated therewith. It is rather of the nature of vegetation. They grow as plants do, or as some plants shoot from the parts of others; from which, though they draw their nourishment, yet each has, as it were, its distinct life and economy. They derive their food from some juices in the body, but not from the nutritious juices of the body; whence they may live, though the body be starved. Wulferus, in the _Philosophical Collections_, gives an account of a woman buried at Nurenberg, whose grave being opened forty-three years after her death, hair was found issuing forth plentifully through the clefts of the coffin. The cover being removed, the whole corpse appeared in its perfect shape; but, from the crown of the head to the sole of the foot, covered over with thick-set hair, long and curled. The s.e.xton going to handle the upper part of the head with his fingers, the whole fell at once, leaving nothing in his hand but a handful of hair: there was neither skull nor any other bone left: yet the hair was solid and strong. Mr. Arnold, in the same collection, gives a relation of a man hanged for theft, who, in a little time, while he yet hung upon the gallows, had his body strangely covered over with hair.
Before we dismiss this subject, we shall give the following curious _Instances of the Internal Growth of Hair_.
Though the external surface of the body is the natural place for hairs, we have many well-attested instances of their being found also on the internal surface. Amatus Lusita.n.u.s mentions a person who had hair upon his tongue. Pliny and Valerius Maximus say, that the heart of Aristomenes the Messenian, was hairy. Caellus Rhodiginus relates the same of Hermogenes the rhetorician; and Plutarch, of Leonidas king of Sparta. Hairs are said to have been found in the b.r.e.a.s.t.s of women, and to have occasioned the distemper called _trichiasis_; but some authors are of opinion, that these are small worms, and not hairs. There have been, however, various and indisputable evidences of hairs found in the kidneys, and voided by natural discharge. Hippocrates says, that the glandular parts are the most subject to hair; but bundles of hair have been found in the muscular parts of beef, and in parts of the human body equally firm. Hair has been often found in abscesses and imposthumations. Schultetus, opening the abdomen of a human body, found twelve pints of water, and a large lock of hair swimming loosely in it. It has, however, been found on examination, that some of the internal parts of the body are more subject to an unnatural growth of hair than others. This has long been known to anatomists; and many memorable instances have been recorded by Dr. Tyson, and others. In some animals, hairs of a considerable length have been discovered growing in the internal parts; and on several occasions, they have been found lying loosely in the cavities of the veins. There are instances of mankind being affected in the same manner. Cardan relates, that he found hair in the blood of a Spaniard; Slonatius, in that of a gentlewoman of Cracovia; and Schultetus declares, from his own observation, that those people, who are afflicted with the plica polonica, have very often hair in their blood.
We shall, in the next place, call the reader's attention to some CURIOUS REMARKS CONCERNING THE BEARD.