?fV^jr'i jf *J ' • •''.y'.V.v'v' i>: t* it /' / />!'>> >,'>'v"/;f ¥;^m'| * * '',y? [ ■■' t' f. r' /"/ t' t'-'f' *' t /' *' *' <-'w >'vy'<•; 7.'.'/' *;/>.*?.!*' •> s ..yivv'-'W < f'f'< ' *■'< *'.'*'*''*', *'.*'*?''*', f 'Xf\'f.y^7.Kfyf^yi.*.f .'rf'y\<*'£ i •'' "• < < ' '' f *'f-.*' '"*' *'..*'*' t' *' Vy'.''". ^lyijV^V^V^Vv,}' r.^ '--.Viu.r'.,/ift' ;- ✓,'✓.' ' /■',./. c: r'W *' *"i"*' "'V'.r'V' i-' 'VrTy^VVy-'**; •; ' -* ■ -' -r'-.K"' **''' '■' »■' '-v»'' 'i 'v ^' '' •' '■ •.'/.' '^vr-fe^sKiift * a. i 5 •:v."y >. / i\*'*':t"f''f'..r\f't,i' f\y t'-yj~yii'^*)y^ffyi\'\ ftf*,f^- « ^'•' ft*'*' f\ '' t"f' *' f' t'f'. * r f ft' f\ f'Jr'I/'.V'i> ":V;' J "' /r-jr-y-'V'1 *,«•• -■•" •" r •'-:' '• ' ':."■■-:-:« <■_■'■■■'■■■'■•■■'• '■■^■'::-r-'^:'■■'-■ :%-rf^'\%t mx- i <->*- . ■ ■55=/os^ \ji^' 'vJ^Tjerys r^vow^WU.^ -J^ '. -<\ ;?/: ......................................... "Y I Surgeon General's Office !?cE' '?)■ ^IfM^ S w *N * - -I tSfcacn, N< /$//2 ^QxXKX^aOaJOGQOGC'QGli 2CC?^y El-' '^'-'^' »■? •. f' *■ HINTS ON HEALTH; FAMILIAR INSTRUCTIONS FOR THE tototi anfo tyxmxMm SKIN, HAIR, TEETH, EYES, ETC, / WILLIAM-EDWARD £)ALE, M. D., MEMBER OF THE BOSTON SOCIETY FOR MEDICAL IMPROVEMENT, FELLOW OF THE MASSACHUSETTS MEDICAL SOCIETY, ETC. aTfjivlJ Efcition, tfjoroysfjlg tebintts, iujtp &.E0 10 ( ?! !' U BOSTON:. TICKNOR AND FIELDS M DCCC I/VII. Q.TA l?5T Entered according to Act of Congress, in the year 1855, by WII.LIAM-EDW ARD COALE, i the Clerk's Office of the District Court of the District of Massachusetts. Stereotyped by HOBART * RODB1NS, New England Tjpe nn.\ Stereotype Founder?, PREFACE. In reviewing several works on the preservation of health, it occurred to us that a person might rise from a perusal of them much in the same condition as that of a distinguished jurist, who, though his head was filled with the legal lore of centuries, was inconveniently arraigned and lined for the infringement of a municipal law, of the existence of which he was wholly unaware. In other words, the reader might be thoroughly informed as to the nature and functions of the greater organs of the system, — the brain, the lungs, the stomach, — and upon the best means of keeping them in good condition, and yet have his comfort greatly interfered with by the derange- ment of some lesser portion of the economy, not thought worthy of mention among the other more important ones. To remedy this defect in books on health, — to gather up these unconsidered trifles, as they may be called in one sense, yet surely not so in all, — to bring them under the sway of medical science, to which they legitimately belong, but whence many of them have greatly strayed, — to apply to them, for the benefit of the sufferer, the same principles of prevention and cure that observation and experience have shown applicable to like affections, on a more extended scale, or in more vital parts, — in short, to deal with these lesser abuses and diseases of our system, with the same reference to common sense, to science and to reason, that we strive to effect in graver matters, — has been our essay in this little book. IV PREFACE. Perceiving a use for our work, we have not slighted any means of fitting it to fulfil that use; but have de- scended into every detail, however small, — into every particular, however trifling, — which we have thought necessary in attaining our end. In doing this, consist- ently with our chief object, we have divested the subject, as much as possible, of all technical words ; have omitted all theories, except where we felt it due to the reason of the reader to give the one on which our advice is founded; have advised only that which a reference to the laws of physiology, assisted by experience, shows to be good, — ignoring all crude notions, and simply popular nostrums, no matter how great favorites they may have been. ^ As our book is, we believe, the first of its particular kind, we have had no one to consult with regard to its general plan and method, or for the bulk of its detail. We feel pleasure, however, in expressing our obligations to the little work of Mr. Erasmus Wilson (the highest English authority on the subject), on '-The Healthy Skin, &c." Erom this we have received most valuable suggestions as to the manner in which diseases of that portion of our system should be considered, and as to their relation to the general health. And where Mr. Wilson has done so well, we have not cared to resort to a too common expedient, of re-casting the original matter into new words. For the rest, we have tried to give credit, as far as possible, to the various sources of our information ; not wishing to shirk responsibility, for that we assume in promulgating it, but on the honorable principle, correct in trifles as well as in great things, "honor to whom honor is due." PREFACE TO THE THIRD EDITION. The success with which this little book met on its first publication would have justified a much earlier issue of another edition, but circumstances prevented. In reviewing it, some alterations which seemed advis- able have been made. These consist chiefly in re-writing more carefully passages which were thought liable to misconception, and in omitting some of the few techni- calities and details which seemed unnecessary, replacing them with more useful matter. The objection made to the size of the type used in the former edition will be found to be perfectly null in the present one. 1* i\ * <■ TABLE OF CONTENTS- PAGE. THE SKIN,....................... 5 The Scarf-skin,................... 7 Color of the Skin,.................12 The Sensitive Skin,.................16 The Sensitive Layer, ................19 Blistering,....................23 Sensibility of the Skin,...............24 Diseases of the Sensibility of the Skin,.........27 Perspiratory Glands,................29 The Oil Glands, ..................36 THE HAIR, . . . .-...................39 THE NAILS, ......................45 Preservation of the Health of the Skin,......47 Ventilation,....................48 Warming Houses,..................53 Diet,.......................55" Clothing......................62 Exercise,.....................76 Sleep, ......................82 Bathing, .....................83 Diseases of the Skin,................91 Chaps and Chafes,.................95 Warts,......................1°° Rashes,......................102 Acne........................104 VIII CONTENTS. PAGE. Salt-rheum,....................106 Itch, ....*...................108 Diseases of the Hair,................Ill- Hair in unusual Situations, ..............112 Too great Profusion of Hair,.............114 Deficiency of Hair..................114 Senile Baldness,..................121 Loss of Color in the Hair,..............124 Diseases of the Hair Glands,.............12G The Care of the Hair,................128 THE TEETH,......................I33 Structure of the Teeth,...............138 The Secretions of the Mouth,.............140 Care of the Teeth,................ . 140 Decay of the Teeth,.................145 Artificial Teeth, ..................149 THE EYES,.......................152 Degree of Illumination,...............155 Direction from which the Light comes,.........156 The Kind of Light used,...............159 Spectacles,.....................165 Sties........................171 To get Foreign Bodies out of the Eye,.........173 THE EAR,.......................175 THE HANDS,......................179 THE FEET,.......................181 Faults of Shoes, ..................182 Corns, ......................191 Treatment of Corns, ................194 Bunions......................196 Distorted Toes,...................197 Turning in of the Great Toe-nail,...........198 Tender Feet,....................199 Chilblains,.....................201 Sweaty Feet,....................201 General Care of the Feet,..............202 Covering of the Feet in reference to General Health, . . 203 HINTS ON HEALTH. THE SKIN. The skin presents itself to us as first in interest among the subjects of which we intend to treat, whether as viewed with relation to the highly important part it momentarily plays in health, or to its liability to disease, and the number of affec- tions which may, in this latter condition, interfere with the proper performance of its functions. Its most obvious and simple use is as a covering to every external part of the body. To fit it to this use, we find it to be a membrane, soft, pliable and elastic, and yet resistant, varying in thickness according to the necessities of the part which it covers : thus, attenuated and supple to the last degree upon the eyelids; thickened upon the palms of the hands; and still further so, to an almost indefinite extent, upon the soles of the feet; and, with the same purpose, thicker upon the outside of the limbs than on their inner surfaces, —* thicker on the shoulders and back than on the sides under the arms. It must be noticed, too, that the relative degree of thickness is not fixed, but, in the performance of this use as a covering and protection, it may, even upon accidental neces- sity, be thickened sufficiently to suit the wants of any other portion which may demand such care. It thus, by an increase of thickness, protects the part under the arm from the head of a crutch, —the outside of the seamstress' finger from the 6 HINTS ON HEALTH. rubbing of the thread, — the shoemaker's knee from the lap- stone. And again, when this use of a part ceases, the skin in time returns to its former condition, and is thin and pliant as before. The outside of the body is not alone thus protected, but the internal portions are also similarly provided with a covering, which, though at first sight apparently very different, yet pos- sesses, in fact, many properties, both of structure and use, similar to those of the skin. This internal skin may be seen, readily, where it lines the eyelids, the nostrils, and the mouth, thinner and redder than the skin, and bedewed, constantly, with a fluid called mucus, from which it takes its name, mucous mem- brane. In health, this mucus is just sufficient to keep the surface moist; but, by any irritating cause, it may be greatly increased in quantity,— as in colds in the head, snuff in the nose, foreign bodies under the eyelids. The differences between this membrane and the internal skin, with which, it must be noted, it is everywhere continu- ous, seem only those which grow out of a difference of use; and, the use being changed, either membrane may change into the other, to suit it to the new demand upon it. Thus, in cases of contractions from burns, where the lip is drawn out- ward and its inner surface exposed, this inner surface soon becomes paler and thicker, and finally assimilates itself per- fectly with the rest of the external skin ; or, were a portion of the skin drawn in by any cause, it would in a like manner soon become, to all intents and purposes, mucous membrane. This interchange of structure and use between these two membranes suggests the existence of a close relation in other matters between them, which we find, indeed, actually to exist, and to play a highly important part in our economy, both for good and evil; so much so, that, where the one is materially affected by disease, the other almost invariably sympathizes to greater or less extent. This will explain for THE SKIN. 7 the most part the coincidence of dyspepsia and bad complex- ions ; the " going in," as it is called, of an eruption, and the grave symptoms following within ; the suppression of perspi- ration, and internal discomfort; fever-sores around the mouth ; itching of the nose in children troubled with worms; eruptions caused by certain articles of diet, such as lobster, etc. Were its use as a covering the sole one the skin had to per- form, its structure might be very simple. This, however, is not the case. We find it has a sensibility varying in dif- ferent parts of the body ; that it exudes a fluid — perspira- tion ; that it affords growth to certain appendages — the hair and nails. For all these purposes its structure must provide, as well as for others which will be explained in due time. Its construction, therefore, is complex, and varying in this com- plexity according to tile demands upon it. Examining its thickness, we find it is not constituted of one layer of membrane, but obviously of two or three, adapted each to the performance of some particular part in the several uses of the skin. THE SCARF-SKIN. The outermost of these layers is the scarf-skin, or epidermis. It is that which is raised by blistering, leaving beneath it a sensitive, redder layer, — the true skin, or dermis. It is com- posed of a material very like horn in composition, and is insensible, thus serving to protect the sensitive true skin, and to dull impressions upon it, which would otherwise prove acutely painful. As might be supposed from its situation and use, this scarf- skin is exposed to continual wear; so that its outer surface is, in longer or shorter time, according to its situation, removed, presenting a fresh surface, which, in due time, is in like man- ner removed. The whole thickness of the layer would thus in time be exhausted, were there not a provision made for its 8 HINTS ON HEALTH. continual renewal. This is accomplished by the vessels imme- diately beneath it, which pour out a thin, transparent, gluti- nous fluid, that soon hardens into minute granules or globules, each endowed with a vitality that enables it to do its part towards the aggregation of the whole into the dense scarf- skin. The fluid continuing to be poured out, another layer of granules is formed beneath, raising the layer of cells from the true skin. This last layer of granules goes through the same process as the first, and is, in turn, raised by still another. In the mean time, the particles of the outer one become dry, are flattened down, and finally form a pellicle or coating composed of thin scales. These scales,~as we have before said, are worn off where the skin is exposed to attrition; and even where it is not they are continually falling off, to be replaced by new ones, so that the scarf-skin may preserve its uniform thickness. This process of nature, in removing the outer layer of these scales, and replacing it with a new one, is obviously with the intent of freeing the skin from impurities which might clog its pores, induce diseased action in the finer vessels, and embar- rass it in the performance of several of its duties; and shows us one means of preserving it in a healthy state, and of con- sequently ministering to our well-being, viz., by washing the skin in a proper manner, and with proper means. The most common and simplest of these latter is pure water. This should be habitually used, at such a temperature as to give the sensation of slight coolness. If very cold, besides the unpleasant sensation produced, it roughens the skin, hardens it, and exposes it to an unequal and undue action, both from the hands in washing and the towel in wiping it. The reliction, too, when the blood driven from the part by the cold returns, is too violent, and an unpleasantly rough and hard condition of the outer skin ensues, causing it to crack or chap, and often laying the foundation of very troublesome sores. THE SKIN. 9 Water at too high a temperature has an equally prejudicial effect, by softening and detaching too many of the scales, leav- ing the scarf-skin too thin, and insufficient to perform its use as a protector to the sensitive layer beneath ; besides which, it has an effect similar to that of water too cold, in disturbing the circulation beneath, and inducing the same chapping, and frequently ugly eruptions. As an assistant to water, we use soap, — a compound of a caustic alkali, a highly acrid substance, as its name would in- dicate, with an oil or fat. The alkali has a strong affinity or desire to unite with animal matter ; and the result of a per- fect union of the two, in such proportion that neither is in ex- cess, is a mild, unirritating compound. Soap is a compound of the two, but in such proportions that the alkali is in excess; and the propensity, so to speak, of this excess to combine with the oil upon the skin, and with the surface of the scarf-skin, gives the soap its cleansing properties. With this simple explanation of the action of soap upon the skin, the requisites for good soap, as well as the cause of the imperfect or injurious action of much of that substance, may be easily understood. If the alkali is too little in excess, — if it is already so united to the oil or fat used in its manufac- ture that there is none left to combine with that upon the skin, — it is inert and useless. If it is greatly in excess, its action is too powerful; it removes too much of the scarf-skin; leaves the part beneath tender; if continued, irritates the ves- sels, and has the same effects that the use of hot water has, but to a much higher degree. How much excess there should be, to produce the proper effect, it is difficult to give a rule for, because all skins are not equally susceptible. Some will not show the slightest irritation under the use of soap that might prove highly acrid to another. Kesan and Castile soaps are without any irritating quality; but the odor of the first, and the hardness of the last are grounds of objection to them. The o 10 HINTS ON HEALTH. odor of the Kesan is not, however, lasting, and we have found it a soap particularly fitted for medical purposes, and for children.* If, when using even the most approved emolient soaps, irri- tation is caused, their irritating influence may be removed in the following manner: — Shave up a cake of the soap, and put it into a wedgewood mortar, with as much soft water as will cover it. When it has perfectly softened, add to it some oil of sweet almonds, taking care that it is not rancid. Rub it up with a pestle until it is a paste of uniform consistence. Keep this in a convenient jar with a cover to it. The effect of this process, it will be readily understood, is to neutralize a portion of the free alkali which caused the irritation. About the quantity of oil to be used it is difficult to give a rule, for it must differ both with the kind of soap and with the suscep- tibility of the skin. It is obvious that our endeavors should aim at using just such a quantity as will precisely neutralize that portion of the excess of alkali that serves to irritate. For the common Windsor soap, we have found that a tea- spoonful and a half may be used to the cake, and not lessen too much its cleansing properties. In the last few years, soaps containing sand and powdered pumice-stone have come much into use. These we cannot but * We would suggest to the reader, if a soap is found that suits per- fectly, to lay in a supply of it, being sure that it is obtained from the identical lot with that experimented upon. Our best manufacturers do not always succeed in reproducing a perfectly similar article, and the next product may not be as equally^ree from unirritating properties as the first. We may mention here, too, that, of all the soaps made in this country that we have as yet experimented upon, we give the pref- erence to Ilaucl's and to Taylor's transparent washballs. Highly perfumed soaps should be avoided. The perfume is given, except in almond soap, by an essential oil ; and though this may be used in such Bmall quantities as to produce no sensible effect, it is nevertheless of an irritating nature. THE SKIN. 11 look upon as injurious. They must exert an irritating influence upon the skin, and, when constantly used, remove too rapidly the surface of the scarf-skin; besides which, the addition of sand is wholly unnecessary, if the soap itself is in the first place properly made. At the same time, we can bear witness, from experience, to the perfect freedom from harm, and the delightful sensations produced, and soft, smooth state of the skin left, by scrubbing it occasionally with fine sea-sand. The objection we make is to adopting it as an habitual article for the toilet. When soap is found to cause chapping in the winter time, Indian meal is often used instead. This is a very harmless substitute, — but only a substitute, — acting by the attrition of its rough particles, and thus mechanically removing impu- rities. But the various washing-powders, of which so many are advertised, should be wholly avoided. If they act chemi- cally, they are only soap pulverized; if they act mechanically, they cannot be better than Indian meal. In either case, then, nothing is gained; and it is always better to let positive well alone, than adopt a very doubtful better. If, in spite of all care in selecting mild and unirritating soap, there should be still an unpleasant irritation of the surface produced, the fault must be looked for either in some innate constitutional peculiarity, of which we have known several instances, or in some temporary derangement of the system, which should be combated by proper remedies. Having said thus much upon washing, it might be deemed too great particularity to give any direction about drying the skin, did we not find extreme notions very prevalent, which must lead to injurious practices. Some, under fear of injuring the complexion, never rub the skin with a towel, — supposing an unhealthy irritation of the surface, causing coarseness, would be thus produced, — but dry it by simply applying the cloth, and that a very fine one, to the surface. Two disadvan- 12 HINTS ON HEALTH. tages might result from this: 1st. The impurities may not be sufficiently removed, but portions of the emulsion formed by the soap, the scarf-skin, and the dirt, may still be left in the depressions of the skin. 2dly. Unless time and care be both taken, from the slowly absorbing power of fine towels, the surface is apt to be insufficiently dried, and to be afterwards irritated by the evaporation of the moisture left. On the other hand, some persons seem to pride themselves upon the coarse- ness of the towels they use, and apparently think that the benefits of an ablution are heightened in direct ratio with the roughness of the crash they use to dry themselves with. This is equally an error with the former extreme. The roughness of the towel must be'proportioned to the sensitiveness of the skin. Some will bear a coarser cloth than others. Two towels should be used : the first of crash, of sufficient rough- ness to produce an agreeable glow after the necessary friction ; next a coarse towel, but of loose texture, and highly absorbing quality, as hucabac, should be passed more gently and slowly over the part, until perfect dryness is produced. COLOR OF THE SKIN. "We have thus disposed of the scarf-skin, so far as it is merely a covering and protection to the true skin; and have laid down the rules necessary to be followed to preserve it in good condition for performing this office properly. It has, however, other properties, which make it of still further inter- est to us. It is the seat of the coloring matter of the skin, which is contained in the granules of its deeper layer. Even in the fairest, these arc not without some color; which is in- creased in quantity, and deepened in tint, in brunette com- plexion, and reaches its maximum, in both respects, in the negro. The chemical nature of this pigment is as yet not understood, from the difficulty of obtaining it in sufficient quantities for analysis. The amount of it varies, even in the THE SKIN. 13 same skin, under different influences. Thus, the heat of the summer increases it, whilst cold diminishes it. Disease, or even a temporary derangement of the internal organs, may have a similar effect upon it. In some cases, persons are born without it, either in the skin or in any of the animal tissues, causing that peculiar appearance in the individual called albinism. This may also occur during life, either wholly or partially, though we do not remember a case of it, except in negroes, who thus become piebald or white. With other ani- mals, albinism is more common than with man ; the rabbit presenting very frequent examples of it, characterized, as in man, by a total want of color in the skin and hair, and by eyes reflecting a pink light. The coloring matter of the skin seems evidently the result of a design which is exhibited continually all through nature, and yet which it is not easy to fully and satisfactorily explain, though many theories, and highly plausible ones, have been broached for its elucidation. The rule is, that the colder the climate, the fairer the color, whether it be of the skin of man, the hair of animals, or the petals of flowers ; arid the reverse, — the nearer the tropics, the darker the hue, the richer and deeper the tint. It most probably has direct reference to the activity of the vessels of the skin, which, under the influence of the light and heat of the tropics, are stimulated to great energy, and thus relieve the internal organs, whilst in a colder climate the activity is wanted by the assimilating organs, those that turn food into flesh and blood. The supply of coloring matter to the skin is not free from a liability to derangement. It may cease partially or entirely, as we have just mentioned, in partial and total albinism, but its faults are most commonly in the other direction. The tint of the granules in the blonde is exceedingly light; in bru- nettes, amber-colored; in the Indian and mulatto, reddish; and in the negro, black. Whatever the complexion, it may, 2* 14 HINTS ON HEALTH. under injurious influence, alter in tint and in hue to greater or less extent, causing in some cases freckles, in others liver- colored spots, and even an almost entire change of complexion in some. This last phenomenon has been several times noticed in fevers. The most frequent cause of alteration of the com- plexion, however, is atmospheric influence. The great vicis- situdes of temperature, in our climate, are particularly ob- noxious to fine complexions. During the summer we have a sun equalling at times that of the tropics, and stimulating the vessels of the skin to an activity which induces great increase in the development of coloring matter; while, in winter, bleak winds and an exceedingly depressed temperature embarrass their action, and induce rapid blanching. Still further to affect the equality of their action, our climate is one of the driest in the world ; and the moisture on the skin, which in other warm regions remains to keep it in a pliant state, is with us rapidly removed by evaporation, leaving the skin beneath harsh and unelastic. To these natural influences, then, we must attribute, for a great part, the want of freshness and brilliancy of complexion, and softness and smoothness of skin, which foreigners notice so much in both sexes; and so far as it does proceed from this cause, so far it is irremediable, except that a few direct precautions — such as common sense would so readily indicate as to make it unnecessary to men- tion them here — may be used against them; but these will prove very limited in their value as preventives. Something might be done, however, indirectly to protect us from these influences, by strengthening the sjstem generally, by genially stimulating the circulation by exercise in the open air, and by properly-directed bathing; by modifying the often too greatly heightened temperature of our houses in winter; by insuring a freer supply of fresh air by day, and still more particularly by night. That most common form of discoloration, called freckles, is THE SKIN. 15 of two kinds: the one consisting of round or irregular-shaped amber-colored dots, of various sizes, occurring chiefly in per- sons of light complexion, — more particularly of that tint always associated with auburn and red hair. These are gen- erally developed during the summer, — most frequently in children, and are called sun-freckles; the other kind consists in various-colored spots, amber, yellow, or pale-green, and may appear at any season. The first, for the most part, dis- appear with their exciting cause, during the winter; the latter are dependent upon coustitutional causes, and are more persistent. Large yellowish or liver-colored spots, irregular in shape, and occurring, unlike freckles, on all parts of the skin, are frequently met with, most often in summer, but appearing also in winter. These, at times, evidently depend upon dis- turbance of the functions of the internal organs, though at others, if so caused, the disturbance is so slight as to escape detection. For the first kind of freckles, and for the last- mentioned spots, many washes have been devised, and many empiric lotions are sold. Some of them may be efficacious ; but there is one objection to all such applications, namely, that the ingredients, unknown, may be deleterious. The most efficient agent that we have found in removing them is a solu- tion of the liver of sulphur, in the proportion of ten grains to an ounce of water. The drawback to the use of this is the odor, which is exceedingly disagreeable. When other appli- cations fail, it may, however, prove of service ; and we there- fore give it with the suggestion that, by using it at night, the disagreeable odor may be prevented from annoying others at least. Mr. Wilson gives the following : Elder-flower Ointment, one ounce. Sulphate of Zinc, twenty grains. Mix it well. Rub this well into the skin at night, and in the morning 16 HINTS ON HEALTH. wash it thoroughly away with an abundance of soap, and apply a lotion made as follows : Infusion of Rose-leaves, one half pint.. Citric Acid, thirty grains. — Mixed. If these applications should irritate, and cause roughness of the skin, use, as a lotion, Almond Mixture, one half pint. Goulard's Extract, one half drachm. — Mixed. If the spots are attended with constitutional derangement, it is scarcely necessary to say that a physician should be con- sulted. Other discolorations, in which the fault is not solely in the granules of the scarf-skin, will be treated of separately, in another place. THE SENSITIVE SKIN. When the scarf-skin has been removed, there is discovered, beneath, a surface looking very much like that of the scarf- skin, but redder, and moist; and the part, when thus recently exposed, smarts. This is the true or sensitive skin ; and the peculiarities just mentioned, by which it differs in appearance and sensibility from the scarf-skin, tell us already something of its construction. In the beginning we described the skin, collectively, as a soft, pliant, and elastic membrane, adapted to the covering and protection of the organs beneath it. The scarf-skin, of itself, can, as may be judged from its construc- tion just described, possess these qualities to but a trifling extent, and, consequently, do but little towards fulfilling this office. It is, therefore, to the true skin that we must look for its performance; and, accordingly, upon examination, we find its construction admirably adapts it to what is required of it. The lower layer, or that termed the corium, is constructed of very minute fibres collected into small bundles, and these are interwoven with each other so as to form a firm, strong and THE SKIN. 17 flexible web. Toward the outer surface, the web is so close as to have the character of a porous felt; but, more deeply, the pores become progressively larger, and upon the inner sur- face have a diameter somewhat less than the twelfth part of an inch. The pores are round or oval in shape, and are sep- arated from each other by strands of fibres double their own diameter, which give to the under surface of the skin the ap- pearance of a coarse net. The strands are connected with the fibrous web in which the fat that lies immediately under the skin is deposited, and the open meshes of this net-like structure are filled with little bags of fat. This admirable arrangement is fully carried out, too, in the constitution of the fibres them- selves. These are of four kinds : the greater part are white and unelastic, but so arranged as to give elasticity to the membrane, just as various kinds of net-work may have elas- ticity, though the thread of which they are made be with- out it; others are highly elastic, but brittle; a third class have both strength and elasticity, and have a contractile power, independent of and in addition to the elasticity; whilst a fourth kind are, as it were, muscular, and have the faculty of independent, and, in some instances, voluntary motion. It is to the contraction in the two last kinds of fibres that the ap- pearance called goose-skin, and the erection of the hair, under cold, or mental emotion, is owing. We scarcely know, after the description we have given of the material entering into the formation of the true skin, and the manner in which it is combined to form this membrane, whether it is necessary to expatiate more upon the peculiar fitness of both for the object in view, — namely, to provide, as we said in the beginning, a soft, pliant, elastic, and yet resist- ant, covering for the body. It may be well to note, however, the closer arrangement of the fibres towards the outer surface, to insure a proper degree of resistance, and also to give a fit surface for the expansion of the sensitive and vascular layers, 18 HINTS ON HEALTH. which we will presently describe. Then, to protect these last- mentioned delicate layers from violence, we find the middle and under portion of the true skin less compact, gradually becoming porous, or net-like, as we descend; the meshes of the net so arranged as not only to be elastic themselves, but, to heighten this quality still further, filled with elastic bodies — little bags of fat. Thus is provided a cushion perfectly adapted to the purpose in view, of yielding upon any violent impulse from without, and preventing a compression of the outer and more delicate layer of the true skin, saving also the scarf-skin from, such bruising as might destroy it. Another value, in the very open arrangement of the lower strata of the skin, is this: When we bend any substance of uniform elasticity and compressibility of structure, the portion towards the concave side is compressed and packed together, while that on the other is stretched, its pores opened, and there would be a layer just in the middle which would be neither compressed nor stretched. Now, if the skin were of uniform elasticity all through its thickness, this would be the case with it: In any crease or fold, the outer layers would be forcibly compressed, the circulation in the vessels hindered, and the delicate and highly sensitive papillae found on this surface, and which we will presently describe, be subjected to a violence which would be hurtful to them, and painful to us. And much the same damage and pain, though not to such ex- tent, would be caused by too great extension of these layers. By having the layer which supports the papilla and stratum of blood-vessels close and but slightly yielding, whilst that beneath can be readily compressed or stretched, the delicate parts are but little affected in any bending of the skin, and the compression and extension are confined almost entirely to the open, porous layer, so admirably constructed to endure it. We before mentioned the increased thickness of the skin over certain parts, such as the palms of the hands, soles of the THE SKIN. 10 feet, the shoulders, outside of the limbs, etc. This increase, though equally shared with the scarf-skin on the palms of the , hands and the soles of the feet, is chiefly given on other parts by the under layer of the true skin. The Sensitive Layer. - Upon the outer and denser layer of the true skin we find spread a delicate thin pink membrane, largely supplied with blood-vessels, to which it owes its color, and as largely with nerves, thatendow it with a high degree of sensibility. The surface of this membrane, when examined under a microscope, is found to be covered with little emi- nences ; or, rather, the whole membrane appears composed of these eminences, which are called papillae. They vary much in size, but they are all similar in their formation. These papillae are planted upon a network of capillary or hair-sized blood-vessels, which supply them, and which them- selves are supplied with blood by larger vessels, penetrating the true skin. Having thus, we hope, made plain to the reader, as far as is necessary, the structure of the true skin, we go on to describe some other of its functions, besides those already explained. The capillary layer may, at first sight, appear of little account in the great animal economy; yet it in truth plays a highly important part in the preservation of our health, and in insuring the safety and healthy action of the internal organs. The vessels entering into its structure are very small, — microscopic indeed; yet, when we consider the number of them, and the large surface over which they are distributed, viz., that of the whole body, we can conceive that their joint capacity is by no means trifling, and that a sudden filling or as sudden an emptying of them may be attended with power- ful effects; and that any prolonged disturbance of their regu- lar and healthy action must be soon followed by serious conse- quences to some other part of the system. More particularly, too, must this be the case when we find that these capillaries 20 HINTS ON HEALTH. form an intermediate communication between the extremities of the veins and those of the arteries; and that, in fact, upon those little vessels, for the most part, do the larger ones de- pend : the arteries to discharge the blood they still retain in their extremities, — the veins to receive the blood, exhausted of its nutrient qualities, which they have to convey to the heart, to be again fitted for circulation. It must be premised, if the reader is not already acquainted with the fact, that in warm-blooded animals the heart is a double organ, or, in fact, there are two hearts each containing two cavities: the one a receiving-chamber, as it were, to re- ceive the blood from the veins, the other a discharging-engine, to force it out through the arteries. Now, to begin the circu- lation, the blood, of a bright red color, filled with nourishing particles and life-sustaining principles, starts from the ven- tricle or dischanring-eno-ine of the left side of the heart, or left heart, and is driven through the arteries over all parts of the system. Having arrived at the termination of the arte- ries, it deposits its nutrient principles, becomes unfitted for further use, and, besides, takes up all the refuse matter thrown off from the neighboring parts as useless to them. This change taking place in the capillaries, — which, it must be understood, are found in great or less numbers in every part of the sj'stem, as well as in the skin, — the blood, now no longer of a florid red, but dark purple in color, must be re- turned to the heart, to be fitted again for circulation. This is done by the veins, through which, by a retrograde course, it arrives at the auricle or receiving-chamber of the riyht heart; thence it is immediately let into the ventricle or discharging- engine, to be forced through the lungs, where, under the influ- ence of the atmospheric air, changes take place in it which render it again red in color, and fitted to nourish the body. It is then returned in this condition to the auricle or receiving- vessel of the left heart, and passing thence out of the ventricle THE SKIN. 21 of the same heart whence we commenced our description of its round. Mr. Wilson, to whom we are already so much in- debted, has illustrated all this very happily by the accom- panying wood-cut. In this, A A', B B', represent the heart. A is the left ven- tricle, from which we pictured the blood of a florid red color, starting to go its rounds through the system; D D represent the arteries through which it thus moves; C, the capillary vessels of the surface of the body, conducting the blood from the arteries to the veins; d, e, f, g, h, capillary vessels in the interior of the body, supplying with blood the various organs, — the brain, liver, stomach, kidneys, etc. A glance will now enable us to understand the importance of the part the exter- nal capillary system plays in the general circulation. If, for instance, it is interrupted, the blood is driven back to find some other channel through which it can complete its rounds. This, in general, is furnished most readily by the kidneys; and the experience of almost every one may have shown them how much more active these organs are during winter than in sum- mer, — an activity particularly noticeable during any sudden spell of cold weather occurring in the midst of a warm season. If the interruption or obstruction is greater, e, the stomach,/, the liver, g, the spinal marrow, h, the brain, and finally even the heart itself, would become overloaded with blood. In a like manner, an overloaded condition of the superficial capil- laries, whether by disease or artificially produced, would ex- r> O 22 HINTS ON HEALTH. haust those of the other organs. We recently witnessed a case in which the most serious consequences were produced in a patient who, to relieve a slight cold, took a warm bath possi- bly a little over-heated. The capillaries of the skin were highly injected with blood, while there was scarcely enough left in the internal organs to carry on the purposes of life, and it was with great difficulty that the equilibrium was restored. The feeling of prostration, and even perfect fainting, some- times produced by a hot foot-bath, is explained in the same manner. The capillaries of the lower extremities are crowded with blood, and there is not enough left in the brain to enable it to do its work. The obvious cure for this condition is to lay the patient at full length, so that the equilibrium in the circulation may be restored. The diagram also will show why the fever and other violent symptoms generally subside, and even sometimes disappear, upon the appearance of the eruption in scarlet fever, measles, etc.; and why, on the other hand, the sudden going in of these eruptions may be followed by very grave consequences; and also why many chronic eruptive diseases act as safety-valves to the system. It may give a hint, too, that cold bathing cannot be practised, as many think it can, with perfect impunity by every one. Of this we have had several instances, where serious consequences have followed both the too sudden adoption of the practice, and a persistence in it when the sj-stem was unfitted for it. Blushing is a phenomenon which is caused by a disturbance of the circulation in the capillary system, the small arteries beinn* for the time highly injected with blood ; and the intense pallor attending violent mental emotion, or fainting, is just the reverse of this condition, the arteries being empty. The paleness after illness may be due to two causes: the most con- stant of these is a languor in the circulation ; the blood is not driven actively through the capillar)- sjstem, and to this is very often added an attenuated condition of the blood THE SKIN. 23 itself, and a want of the proper amount of coloring matter in it. The purple hue and mottled appearance produced by cold is caused by the capillary arteries being emptied of their red blood, while the circulation in the capillary veins is slug- gish, permitting them to retain their dark-colored fluid. The agency of this system is also concerned in distributing over the surface, and indeed through all the organs at times, the yellow hue of jaundice. The bile, instead of being properly disposed of by the liver, remains in the circulation, and is deposited by the capillaries in the surrounding tissues, where it stays until the absorbing vessels remove it again. Blistering. —With the description we have thus given of the capillary system of the skin, the object and effect of blister- ing can be readily understood. To attract away, so to speak, the blood that is filling the vessels of an internal inflamed organ which is not able to bear the inflammation, and the integrity of which is important to life, we set up an inflam- mation in the sensitive skin, which is able to bear it, and the integrity of a portion of which is comparatively unimportant, by the application of some irritating substance — ointment of Spanish flies, for example. The capillaries first become filled, and then permit the thinner colorless portion or serum of the blood to ooze through them, and form a cavity between the papillary layer and the epidermis, by pushing up the latter; — this is the blister. When the inflammation we wish to re- lieve is slight, or not of long standing, having drawn the blis- ter, a mild, soothing ointment is applied to heal it up. If, however, the amount or duration of the internal inflammation is so great as not to be removed with such despatch, the blis- ter is kept " open." This is done by dressing it with some stimulating ointment, which will keep up the irritation of the blistered surface. As the epidermis, even when it has been separated from it, forms the most soothing covering to the sensitive skin beneath, 24 HINTS ON HEALTH. in burns we disturb it as little as possible; but, for an obvious reason to the contrary, when we wish to keep a blister open, all the separated epidermis should be removed. It does not increase the suffering, if it is properly done, and the trouble is fully compensated for in the increased efficiency of the remedy. Sometimes the surface thus bared, instead of continuing to discharge serum as it should, becomes a deeper red, dry and very painful from over-irritation. In this condition, not only is its excellence as a blister very much lessened, but it adds to the excitement under which the general system is already laboring, and thus increases, instead of diminishes, the disease. To correct this, a thin light poultice of bread and milk should be applied, and renewed every four hours, until all the untow- ard symptoms disappear, when the ointment, with its strength diluted, may be again resorted to. The activity of the absorbing vessels of the capillary system — those that remove the effete matter in their neighborhood, and carry it either to some point at which it can be thrown off, or be renovated and fitted again for use — has been taken advantage of to introduce medicines into the system, in cases where the use of the stomach for that purpose is inadmissible, — those of prolonged vomiting, for instance. As might be expected from its office as protector to those vessels, the epi- dermis must first be removed by a blister, and the medicine is then applied in such form as is best suited for absorption, viz., one of minute division, either fluid or powder. Sensibility of the Skin. — We mentioned that in the formation of the papillae nerves accompany the blood-vessels. To these is due the sensibility of the skin, a quality which supplies us with the sense of touch. This sensibility differs very much in different persons, and in different parts of the surface of the same person. With some, the sensibility may be so dull as to be considered the result of almost a paralysis or cessation in the function of the nerve; with others the ex- THE SKIN. 25 altation of sensibility may arise to such a height as to become really a disease, and that a very distressing one. Constitu- tionally, some persons have a much higher sensibility of the skin than others, and what is not felt by one may be a very severe annoyance to another. We should, therefore, be care- ful how we accuse others of too little patience, because they are annoyed at impressions which affect us but slightly, or not at all. The old saying, that no one knows how the shoe pinches so well as he that wears it, is very applicable here. Children are more impressible than grown persons, as is in- stanced by the torture that many are put to by a bite or two from a mosquito or flea. Females are in general more im- pressible than males — those of a nervous temperament more than those of a bilious or of a lymphatic. Besides this difference in the sensibility of individuals, there is a great difference in that of different parts of the surface of the same individual. Dr. Webber, of Leipsic, has illustrated this by an original and very simple experiment, viz., by touch- ing the various parts of the surface with the two points of a compass, and trying how near the points could be approximated and still give two distinct sensations. On the tip of the finger they could be brought within a third of a line of each other; while on the middle of the arm or thigh they had to be sepa- rated to the distance of two and a half inches. On the point of the finger, the distance necessary was two lines; on the cheek, five; on the forehead, ten; middle of the breast, twenty. We have repeated these experiments, with a similar result, as far as regards the ratio of the sensibility of one part to another, but with different result as regards the actual dis- tances mentioned; and this is as might be expected from what we have said above — that some persons are more sensitive than others. Another peculiarity we noticed, in testing the sensibility of the tips of the fingers, was that the tip of the ring-finger was more sensitive than that of the fore-finger, 3* 26 HINTS ON HEALTH. though the latter is always used when we wish to exert our sense of touch, and is by some considered the peculiar organ of this sense. The truth, in all probability, is, that originally it does possess more sensibility, — certainly as much as the other fingers, — but it becomes dulled and obtuse by constant use, just as the part of the retina in the eye upon which the image of objects habitually strikes is not so sensitive as the neighboring parts; so that in feeble light we can catch the outline of an object very distinctly by looking at another ob- ject near it, whilst by direct vision we might not be able to see it at all. Dr. Webber noticed another phenomenon, which we are inclined to account for in the same manner. Putting both hands into the same vessel of warm water, the left felt the warmest, the habitual use of the other probably rendering its sensibility obtuse. He also remarked, what experience has often taught us, that putting a single finger into a vessel of warm water, we could bear it readily, while, on plunging the whole hand in, the pain was insupportable. In other words, an impression made upon a small surface may convey no sense of pain, whilst the same impression extended over a large one would be unbearable. This is too apparent and common-place to make it worthy of note, did we not find that a frequent disre- gard of it subjected many patients to suffering. Thus we have seen a poor invalid much pained by a foot-bath, the temper- ature of which the attendant has, upon the experience of a single finger, given honest assurance was not too high. Upon the same experience, too, we have seen a poultice applied, which, besides causing great suffering, materially affected the inflamed part for the worse. We majr mention here, too, that the hands — in all probability, for the same reason that the right hand is more obtuse than the left—are better able to bear heat than any other part of the body, and therefore their power of endurance should never be taken as a criterion. The sensibility of the skin, as with all other of our attri- THE SKIN. 27 butes, may be increased by exercise; or, on the other hand, be repressed and dulled by disregard to its appeals, or by ex- ternal influences upon the organs of touch. The blind furnish us with most common and frequent instances of the increase of sensibility. Besides the ability to read with rapidity letter- press from raised type, of a size that would prevent any one of unpractised fingers distinguishing the individuality of a single letter, and performing many other every-day acts re- quiring great nicety of tact, well-authenticated instances are on record of their being able to distinguish colors, simply from the different degree of smoothness given by one dye above an- other. The reverse of this is found in followers of mechanical arts, where rough or heated bodies are frequently handled. We have often seen a chemist remove, with his naked fingers, a vessel in which water was boiling; and blacksmiths handle freely pieces of iron heated to a degree that would prove highly painful to one unpractised. Disease of the Sensibility of the Skin.—The sensibility of the skin, which in its healthy action ministers so much to our comfort, communicating to us so many pleasurable sensations, or warning us, by painful ones, of what may, if not remedied by timely care, harm us, is liable to diseased conditions, in which it may as greatly inflict upon us the most exquisite tor- ture, or convey to us sensations entirely different from those we ought to receive from the source of impression. The case related by Dr. Darwin, and made still more famil- iar by Wordsworth's ballad, of a young farmer, who, after the malediction of an old woman, never again felt warm, is one in which, though the disease did not originate in the skin, as in- deed it seldom does, the sensitive layer was the chief seat of the painful emotion. This is also the condition in the cold stage of intermittent fever, while, as a reverse of this sensation of cold, in the collapsed stage of cholera, though the skin may feel icy to the stander-by, intense heat is felt in it by the 28 HINTS on health. patient. We have also seen, both in this disease and in neu- ralgia, such a state of exalted sensibility, that the weight of a fly upon the surface would horribly increase the already in- tense agonies of the sufferer; and, in the last-mentioned dis- ease, there is often, as in cholera, the sensation of great heat, whilst the skin is unaltered in appearance. Though it is very difficult to make comparative estimates of the amount of suf- fering of one kind with another, our observations lead us to believe that perverted sensibility of skin, causing a sensation of itching, is probably productive of the most intense agony. A patient of ours, whose powers 6f endurance had previously been well proved under a formidable surgical operation, re- marked that her sufferings then were not to be compared with the tortures of an itching which affected her subsequently; and Mr. Wilson was told by a lady that the application of a sponge dipped in boiling water was perfect bliss, contrasted with the pungent' suffering of the other infliction. This affec- tion is, fortunately, not a very common one, except from acci- dental causes, generally operating upon the digestive organs, and it is generally met with in old people. Besides these, the skin is sometimes affected with the sensa- tion of insects crawling over it, or darting pains, smarting, tingling, etc. All these are generally dependent upon either some disease of the great nervous centre, the brain and spinal marrow, or of the digestive organs, though sometimes they are forerunners of some active disease of the skin itself. It may be gathered readily from what we have said of the sensibility of the skin, both in health and in disease, that it affords a most powerful and efficient means of impressing the nervous centres, and as such it has been used both for good and for evil. Dropping water on the forehead, from a height, was used as one of the tortures of the inquisition, — the irritation of the nerves of the skin by that means becoming so intense as to TnE SKIN. 29 finally affect the brain; and the criminal records of France exhibit a case where death was caused by first confining the victim, and then tickling the soles of the feet, — the effect being as in the-former case, to produce such powerful excitement of the brain as to extinguish life. As a reverse of this, and for better purposes, the soothing influence of gentle frictions with the hand, or of combing the hair with slow and measured regularity, are remedies of by no means trifling efficiency in nervous excitement, frequently producing quiet and sleep, and doing awaj- the necessity of opiates. Even the first-mentioned torture we found very serviceable in one case, as an indispens- able assistant to our other means, and one without which they would have failed. An elderly lady, by mistake of the apothe- cary, took thirteen grains of a powerful narcotic. When the mishap was discovered, she was already deeply under the in- fluence of the drug, and it was absolutely necessary that she should be awakened and kept awake until the antidote could act. To effect this seemed impossible, as with one of her age those acts of gentle violence generally resorted to, such as walking about, shaking or slapping the patient, were entirely out of the question. The above mentioned torture occurred to us, and it was soon put into operation, by suspending a lump of ice in a towel above the head. As the ice melted, the water fell, drop by drop, upon her forehead, while she lay be- neath ; and in a short time such an irritable state of mind and body was induced, that tendency to sleep was for a time entire- ly removed. The remedy had, however, to be renewed occa- sionally, but at intervals longer and longer, until all disposi- tion to somnolence disappeared. PERSPIRATORY GLANDS. In the preceding pages we have confined ourselves to the description of those layers of membrane which constitute the 30 HINTS ON HEALTH. protecting envelope of all parts of the body. Besides its office of a covering, we have shown that the skin is endowed with a nervous system to which it owes its sensibility, and with a vascular system, which plays a very important part in the ani- mal economy. In addition to these, there is within the skin, though not so essentially a part of it as the last, a -series of organs, whose office is to form and convey to the surface, there to be thrown off and discharged, that fluid known as perspira- tion. Like the vessels of the skin, these organs are minute, microscopic, and individually insignificant. Yet, also, like those vessels, in their united action, their influence is of vital importance to the system at large; and any embarrassment to the healthy performance of their functions must be attended with greater or less damage to the general health. The organ which forms the perspiration — which separates it from the blood — is a minute tube, coiled irregularly upon itself; in fact, a perfect tangle of microscopic tubing. In close contact with this tubing is a capillary blood-vessel, from the blood in which, by a vital action, the perspiration is separated, and passes into the tube. Between the tangled portion, or gland, as it is called, and the surface of the corium, the tube, now called the duct, is straight; but, when it enters the epi- dermis, it assumes a very regular cork-screw spiral, and in this form reaches the surface, where it discharges the perspi- ration by its mouth, called the perspiratory pore. The spiral arrangement of this tube, as it passes through the epidermis, before it was fully understood by means of the microscope, perplexed physiologists greatly. It was contended that, as the epidermis is impermeable to fluid, and retains so perfectly the serum of a blister, there surely could be no opening through it. Others, seeing the difficulty of this explanation, cleared the matter o ttheir own minds very satisfactorily, by furnish- ing each duct with a little valve, by which it could shut itself up when it chose, and' which, when closed against its will, THE SKIN. 01 caused fever; a very useful theorj7, explaining two phenom- ena, but, like many others equally beautiful, not borne out by stubborn fact. The microscope has done away with all necessity for such valves, by exhibiting the true arrangement of the spiral, by which any pressure upon it, forcing the coils together, closes the aperture. Another reason, too, for the fluid in a blister not leaking out through the pores is, that when the scarf-skin is raised, it draws out from the straight part of the duct in the true skin a portion of its delicate lining, and this, it is evident, must act as a very efficient valve at the inner surface of the scarf-skin. We will now call mathematics to our aid, to help us in illus- trating the importance these perspiratory glands acquire from their numbers, and the amount of work they do in their united labors, using the calculation of Mr. Wilson for our purpose. " To arrive at something like an estimate of the value of the perspiratory sjrstem in relation to the rest of the organism, I counted the perspiratory pores on the palm of the hand, and found 3528 in a square inch. Now, each of these pores being the aperture of a little tube about a quarter of an inch long, it follows, that in a square inch of skin on the palm of the hand there exists a length of tube equal to 882 inches or 734- feet. Surely such an amount of drainage as seventy- three feet in every square inch of skin, assuming this to be the average for the whole body, is something wonderful; and the thought naturally intrudes itself, What if this drainage were obstructed,— could we need a stronger argument for enforcing the necessity of attention to the skin ? On the pulps of the fingers, where the ridges of the sensitive layer of the true skin are somewhat finer than in the palm of the hand, the number of pores on a square inch a little exceeded that of the palm; and on the heel, where the ridges are coarser, the number of pores on the square inch was 22G8, and the length of tube 507 inches, or 47 feet. To obtain an estimate of the 32 HINTS ON HEALTH. length of tube of the perspiratory system of the whole surface of the body, I think that 2800 might-be taken as a fair aver- age of the number of pores in the square inch, and 700, con- sequently, of the number of inches in length. Now, the num- ber of "square inches of surface in a man of ordinary height and bulk is 2000; the number of pores, therefore, 7,000,000, and the number of inches of perspiratory tube, 1,750,080; that is, 145,833 feet, or 48,600 yards, or nearly twenty-eight miles." At ordinary temperatures, in health, the perspiration passes off in the form of vapor, called the insensible perspiration. Under excitement of exercise, elevated temperature, or mental emotion, and in certain conditions of disease, the quantity of fluid secreted by the perspiratory glands is so great as to ap- pear upon the surface in the form of a watery fluid ; this is the sensible perspiration. The uses of this perspiration are several, — some of a nature not to be understood by the reader readily, unless prepared by a knowledge of some of the more complicated processes constantly taking place within us, and with the departures from the proper type of these occur- ring in the disease. Its most obvious, and, for our every-day occasions, most practical use, is as a regulator to the temperature of our bodies, its effect being to reduce it. Chemistry teaches us that the vapor of water contains a very large portion of what is called latent heat; that is, heat the properties of which are not sensible, — heat which lies hidden, but which nevertheless has been emplojTed in converting the water into vapor, and which is still contained in the vapor. Now, when we recall the fact of the existence of 7,000,000 of little steam- pipes, each discharging its quota of vapor, and this vapor con- taining its amount of latent heat, we can form some idea of the whole quantity of heat given off at every moment from the surface of the body. Having thus enabled the reader to THE SKIN. 33 form some estimate of the power of this agency, we will now exhibit the necessity for its operation. Man, as the lord of creation, — the intended ruler, under a higher power, of every portion of the globe, — must be fitted for all the exigencies to which any part of his dominions may subject him. A very obvious one of these is the ability to endure the temperature of the various zones in which he may have his habitation. At the pole this temperature is reduced at times to 70° below zero; at the tropics it attains an eleva- tion of 120°. Within him there is, and must be, a heat-gen- erating apparatus. The'amount of heat generated by this apparatus we may regulate, to a certain degree, by the quan- tity and kind of fuel — the food we put into it; but, how- ever we may attend to this means of regulation, our comfort, nay, even our safety itself, requires that there should be an overplus of heat at all times furnished to meet any sudden demand upon it; and, consequently, as this heat cannot be retained, it must be let off as fast as generated, unless it is wanted for immediate use. The perspiratory ducts then fur- nish the safety-valve or scape-pipes by which this heat is let off when not required. Thus, as we approach the poles, they become habitually closed more and more ; as we approximate to the tropics, they are more and more opened, and act with more and more freedom, until, with some, they pour out almost continually, not only an insensible vapor, but a sensi- ble fluid, keeping the surface at all times bedewed with moist- ure. So much as a matter-of-fact explanation of the use of these small microscopic organs, — a use it will, by this time.be perceived, of the highest importance, and one which cannot cease, or even meet with any great interruption, without the most serious consequences ensuing. Our feelings of com- fort or discomfort, under atmospheric influences, it will now be understood, are dependent rather upon the ability of the 4 b4 , HINTS ON HEALTH. perspiratory organs to form the fluid, and give it out with the heat it contains, than upon any particular elevation or depres- sion of temperature ; and the complaints of visitors from the tropics against the overpowering heat of even our northern summers may be explained. As long as the skin pours out the vapor or fluid of perspiration freely, a very large share of the effects of the elevated temperature is gotten rid of; but let the air be loaded with moisture, so as to check the evap- oration from the surface, or let a damp wind, at a lower tem- perature, come up, so as to embarrass the action of the glands, and we at once suffer. The advantage that the inhabitants of the tropics have over us is, that though the heat may be greater, yet it is more equable ; the system is not-so often de- ranged by atmospheric changes, and the skin goes steadily on in its work of cooling it down. The degree to which the human system can bear heat, under circumstances favorable to the free action of the perspira- tory glands, may at first surprise the reader. Persons have, without great inconvenience, endured an artificial temperature of nearly 400°, the air being perfectly dry, so that the perspi- ration could be rapidly given off. The writer has experienced a temperature of 200°, without suffering in the slightest, whilst the air was free from moisture. Upon trying, however, a temperature of 130°, loaded with watery vapor, the pulse was greatly excited, the breathing became hurried and labored, and great general distress ensued—all of which symptoms were only lessened by the fortunate readiness of the skin to relieve the oppressed organs. The value of a free perspiration as a symptom in'acute febrile disease, and the desirability of producing it in certain cases, may also now be readily understood. By it the over- heated surface and internal organs are cooled, the congested vessels relieved of their fulness, and its equilibrium restored to the circulation — conditions highly necessary to the return THE SKIN. 35 of any diseased organ to its healthy state, and to the well- being of the general system. Yet, a careful appreciation must be made of the cases in which it is desirable to induce perspiration, — a thing not al- ways done by the uninitiated, — and much harm has been caused by efforts to induce it, under hope of relieving the in- valid, when to do so is utterly impossible, and when, even could it be done, no benefit, but rather the reverse, would re- sult. The only cases in which domestic treatment avails for this purpose are those of very recent colds, and rheumatic attacks. In these, if the remedy is applied in the very first stage, whilst the organ is only laboring from a congested state of its vessels, or before inflammatory disorganization has actually commenced, a free perspiration may cut the attack short, and save the patient from a graver disease. If, how- ever, matters have gone a point beyond this, and true inflam- mation been established to such a degree as to produce vital changes in the natural and healthy condition of the part, perspiration, if it can be produced, which is seldom the case, will only cause a debility that must lessen the aptness of the part to recover. , Not unoften, too, the means used — gener- ally hot stimulants — tend directly to increase the undue ex- citement already existing. To finish what we have to say upon this particular subject, we will mention that the most effective of domestic remedies, administered to produce perspiration, are hot drinks, simply, or containing some diffusible stimulant — lemonade, balm or sage tea, with the addition or not of gin or brandy. Tea made of thoroughwort, where delicacy of the stomach does not prevent, is probably the most efficient of this class of reme- dies— its excellence in the first stages of that distressing form of influenza, characterized by such intense pains in the limbs as to obtain for it, in the south, the name of Break-bone 36 HINTS ON HEALTH. Fever, having given to the herb throughout the same region the name of Boneset. THE OIL GLANDS. There are still other organs pertaining to the skin which require our a'ttention. These are the oil glands. They greatly resemble, in general structure, the perspiratory glands, but are rather more complicated. They are not so equally distributed over the surface as the last, for, while some parts, such as the palms of the hands, and soles of the feet, are en- tirely deficient in them, others are plentifully endowed with them — so much so as to give a very perceptible difference of aspect to the skin. They are found in greatest numbers over the nose and adjacent parts of the face, along the edge of the eyelids, within the ear, and wherever there is hair requiring the softening influence of the oil they secrete to keep its roots in a moist and pliant state. The most obvious and common use they perform, in addi- tion to that just mentioned, of ensuring a soft and pliant con- dition of the hair, is to protect the skin from the influence of fluids, with which the surface is liable to be bathed, and from atmospheric vicissitudes. On the edge of the eyelids they tend, by the repulsion which oil exerts upon watery fluid, to restrain the tears within their proper bounds. In the ear, besides contributing to keep the passage soft, and in a condi- tion favorable to the transmission, in proper degree, of sound, the bitterness of the cerumen, or wax, they manufacture, re- pels small insects from entering. As long as the skin goes on in a natural and healthy man- ner to perform its manifold work, and every part exerts its due degree of activity, the sebaceous or oil glands unobtru- sively manufacture the fatty or oily matter, and discharge it upon the surface where it performs its use, and, having done so, is removed in washing. But all are not blessed with a skin THE SKIN. 37 so perfect in its routine of duty, and with many it is often sluggish in the performance of its functions. With such the glands manufacture the oil, but instead of its being discharged together with the little bags in which it is first contained, these latter burst, give out their contents, and dry up ; their contents harden into a cheesy consistence, and the whole is retained in the duct, or tube, by which it should have found exit at the surface of the skin. The tube becomes distended by fresh formation of sacks of oil, and its mouth collects smoke and dust, so as to form a black point, obtrusively visible upon the surface. These, of course, where the glands are numerous, become correspondingly so; and, in many instances, a most unsightly appearance of the skin is produced. Sometimes the skin immediately around these points becomes inflammed, and tumefies, forming a little red eminence, with a black point in its centre. There are few, if any, affections so really trifling in themselves, which are so unpleasant to the affected party, as these' collections in the oil glands, and the inflammation that sometimes accompanies them. We call them trifling in themselves, for tljey seldom, if ever, are attended with any suffering; but they are really not so trifling, when viewed in the lio-ht of symptoms. They almost always indicate a sluggish state of the circulation of the skin, and an indolence in the performance of its other functions, besides that of supplying its surface with oil. It will be found, too, that the digestive organs participate in this indolence, and the whole intestinal canal, is not inoften similarly slothful, causing constipation, colics, and much general uneasiness and discomfort. To these last organs we must, indeed, as a general thing, look for the original disease, and to them we must first give our attention in attempting to relieve the external affection. The stomach must first be spared from any over-taxation, by limiting the diet to simple, easily-digested and nutritious food. The bow- els must be relieved from their torpor by gentle and simple 4* 38 HINTS ON HEALTH. means, so that a free evacuation may be produced, at least once a day. For the latter purpose, we have, as a general thing, found nothing better than rhubarb : * and, as the readi- est way of taking it, the patient should chew a piece, of such size as experience teaches to be necessary, upon first getting up in the morning. It will be noticed, however, that we only speak generally; particular idiosyncrasies may require a con- siderable modification of this treatment. This is as much as can be done to the general system safely, without further knowledge of the particulars of the case. As to the skin it- self, partial or general bathing will be found beneficial in stimulating it to more vigorous action, the bath being as cold as the strength of the patient will bear, and reaction hastened by brisk friction with a soft towel. To remove the collection of sebaceous matter with its black point from the gland, we have found it useful to soap the part over with a soap suffi- ciently emollient not to chap or irritate the skin, before going to bed, and using care to cleanse it well away at the morning ablution. When the immediate neighborhood of the glands is inflamed, any efforts directed to the skin itself must be made very gently and carefully, for fear of increasing its inflamed * state. Warm water will then prove more grateful than cold ; and as an application to soothe the irritation, and to hasten the removal of the sac, we have found bitter almond soap very serviceable.! * It may be well to mention in what rhubarb has advantage over other aperients, for the general purpose of evacuating the bowels. It is in its possessing a tonic property, which, while other aperients often used tend to weaken the bowels, so as to frequently require an in- croase of the dose to produce the necessary effect, enables it to increase tlie tone of tlie organs so as to act for themselves, and do away with the necessity of aid. t In the course of this work, we would carefully avoid any expres- sions that might seem like praising an empirical nostrum. On the other hand, we feel it perfectly consistent with such a determination to men- THE HAIR. 39 It is well known that when the distended glands are squeezed between the two finger-nails, the fatty matter within is forced out, preceded by the black point, and, being moulded by the aperture through which it issues, looks like a worm, and is, in fact believed to be one by many people. Strange as it may appear, though not a living animal itself, this fatty matter always contains a number of animalcules. They are elongated in shape, with a blunt head, wdiich, as the animal lies in the tube, is directed inwards towards the gland. The largest yet seen by Mr. Wilson, whose paper on the subject was published in the Philosophical Transactions (1844), was the third of a line in length. The number in each gland varied from two to twenty, increasing with the torpor of the skin, or with the de- caying powers of life of the individual. He discovered them in all stages of their existence, from the egg to the perfect animal. Mr. Wilson suggests, with great plausibility, that these little creatures are by no means useless, as, indeed, it might be presumptuous to say of any created thing; but that, in all probability, their purpose is, to remedy, to some degree, the inability of the skin to throw off effete matter, and, by breaking up the oil sacks, favor the discharge of their con- tents. THE HAIR. Besides the epidermis, there are two other structures formed by the skin, for much the same purpose, that of protecting it, but to a more partial extent and degree than the scarf-skin tion any preparation which will serve our purpose, and which may be more convenient than, and equally efficacious with, a more formal and scientific looking prescription : as such we here mention, as useful in the inflammation of the oil glands, Almond Shaving Paste, made by Roussel, taking care it is not rancid. It should be smeared on at night, and removed with warm water in the morning. 40 HINTS ON HEALTH. does. These are the hair and the nails. They much resemble each other in their structure, which also closely allies them to the scarf-skin, being formed, like it, from microscopic cells, which, according to the age of their formation, and to their situation, become dried, flattened, split, etc., as may be neces- sary to fit them for the purpose required of them. Every part of the surface produces hair, excepting the palms of the hands and soles of the feet; but the hairs of the different parts of the surface vary much in several particulars. Over the greater portion of the body they are short and fine, scarcely perceptible in some places. The eyebrows exhibit them of stronger growth and greater length, though still very limited in th~e latter quality. In the whiskers they commonly grow much longer, and still more so in the beard, whilst on the scalp, in their luxuriance and length of growth, they attain their maximum. Hairs are formed by glands, situated either in the sub- stance of the true skin, or in the fatty cushion beneath it. The gland consists of a little sac, at the bottom of which is an eminence, like those we described as forming a layer of the skin, and largely supplied, as those are, Avith nerves and capillary blood-vessels; from the contents of the latter the hair is manufactured. The hair, when formed, finds its way outward to the surface through a tube, like the ducts of the perspiratory and oil glands, lined with scarf-skin. Into these hair-ducts very frequently one, and sometimes two, ducts of the oil glands open, so as to give the root of the hair the advantage of the softening influence of the oil — a knowledge of Avhich fact may serve as a hint that possibly less pomatum is needed to benefit the hair than is often supposed. The process of manufacturing the hair, so to speak, is much like that by which the scarf-skin is formed. First a fluid is poured out by the papillae from the blood contained in its capillary vessel. This fluid, gradually drying, forms first into THE HAIR. 41 granules, then into cells, and these cells are aggregated to- gether in the form of the hair. The hair thus produced is not, however, of uniform structure, but, on examination with the microscope, we find that the cells w'hich constitute it pre- sent three different modifications. In the centre of the hair, which is less dense than the other parts, the cells are but little, if at all, altered ; collected, as it were, comparatively loosely together, so as to form a pith, perfectly analogous to the pith of a feather. Immediately outside of this pith the cells are split so as to form fibres. These constitute the chief thickness of the hair, and give it its strength. Outside of this again is another lajrer of cells, but dried and flattened into little plates or scales, so that in the rough the hair has much similarity to a young twig of a tree; pith in the middle, fibres giving it strength outside of this, and a coating or bark outside of all. The fact of the outer surface of the hair being formed of scales overlapping one another, showing, of course, a free edge directed outward towards the end of the hair, will explain why hair is smooth wdien rubbed in one direction,— that is, from root to point,—but rough in the other; and why, when we hold one between the finger and thumb, and make these glide upon it backwards and forwards in the direction of its length, the hair invariably moves root foremost. These scales, too, will give explanation of a process of great importance in the manufactures, that of felting, as it is termed. It consists, in brief, of the matting together of hair by means of the catch- ing together of these scales. It is effected by means of a cat-