Читать книгу A Treatise on Physiology and Hygiene - Joseph C. Hutchison - Страница 9

Table of Contents

The Integument—Its Structure—The Nails and Hair—The Complexion—The Sebaceous Glands—The Perspiratory Glands—Perspiration and its Uses—Importance of Bathing—Different kinds of Baths—Manner of Bathing—The Benefits of the Sun—Importance of Warm Clothing—Poisonous Cosmetics.

1. What is the skin? Parts directly beneath? What is shown?

1. The Integument.—The skin is the outer covering of the body. The parts directly beneath it are very sensitive, and require protection. This is shown whenever by accident the skin is broken, pierced, or torn off, the bared surface being very tender, and painful to the touch. Nature has provided the body with a garment that is soft, pliable, close-fitting, and very thin, and yet sufficiently strong to enable us to come in contact with the objects that surround us, without inconvenience or suffering.

2. Microscopic examination? What is the cutis? The cuticle? Their union? How separated? What further is said of the cuticle?

2. The Structure of the Skin.—When examined with the aid of the microscope, the skin is found to be made up of two layers—the outer and the inner. The inner one is called the cutis, or true skin; the outer one is the epidermis, or scarf-skin. The latter is also known as the cuticle. These two layers are closely united, but they may be separated from each other. This separation takes place whenever, from a burn, or other cause, a blister is formed; a watery fluid is poured out between the two layers, and lifts the epidermis from the true skin.

Of the two layers, the cuticle is the thinner in most parts of the body, and has the appearance of a whitish membrane. It is tough and elastic, is without feeling, and does not bleed, when cut. Examine it more closely, and we observe that it is composed of minute flat cells, closely compacted, and arranged layer upon layer.

3. Wearing out of the cuticle? What then? Variety in thickness of cuticle? How accounted for?

3. The outer layer is constantly being worn out, and falls from the body in the form of very fine scales. It is, also, continually forming anew on the surface of the inner layer. Its thickness varies in different parts of the body. Where exposed to use, it is thick, hard, and horn-like, as may be seen on the soles of the feet, or on the palms of the hands, especially of those who are accustomed to perform much manual labor. This is an admirable provision for the increased protection of the sensitive parts below the skin against all extraordinary exposure. Even the liabilities of these parts to injury, are thus kindly provided for by "the Hand that made us."

4. Location and office of the cutis? What further is said of it? Papillæ? Touch?

4. The cutis, or true skin, lies beneath the epidermis, and is its origin and support. It is firm, dense, elastic, very sensitive, and is freely supplied with blood-vessels. It is closely connected with the tissues below it, but may be separated by means of a sharp instrument. The surface of the cutis is not smooth, but is covered here and there with minute elevations, called papillæ. These are arranged in rows, along fine lines, or ridges, such as those which mark the palm and fingers; their number is about 80 to the square line (a line being one-twelfth of an inch). These papillæ contain the blood-vessels which carry the supply of blood needed by the ever-wasting skin. They contain nerves also, and are largely concerned in the sense of touch; hence they are particularly abundant where the touch is most delicate, as at the ends of the fingers.

5. What are the nails and hair? The growth of the nail? The rapidity of its growth? Accident to the nail?

Fig. 14.

a, b. The Root of a Hair.

1, 2, 3. The skin forming the hair sac. 4. Sebaceous glands. 5. The hair sac.

c. Transverse Section of a Hair.

5. The Nails and Hair.—These are appendages of the skin, and although very unlike the cuticle as it appears on the surface of the body, they are, in reality, modified forms of that layer of the skin. The nail grows from a fold of the cuticle at the root, and from the under surface. As fast as it is formed, it is constantly being pushed outward. The rapidity of its growth can be ascertained by filing a slight groove on its surface, and noticing how the space between it and the root of the nail increases, in the course of a few weeks. When the nail is removed by any accident, it will be replaced by a new one, if the root be not injured.

6. How are the hairs produced? Difference in their length?

6. The hairs are produced in a similar manner; the skin forming depressions, or hair sacs, from the bottom of which they grow and are nourished (Fig. 14). They are found, of greater or less length, on almost all parts of the surface, except the palms of the hands and soles of the feet. On certain parts of the body, they grow to great length; on other parts they are so short, that they do not rise beyond the hair sac in which they originate.

7. Root of the hair? Shaft? Firmness and softness of the hair?

7. The bulb, or root, from which the hair arises, is lodged in a small pouch, or depression in the skin. The shaft is the part which grows out beyond the level of the skin. Its growth is altogether in one direction, in length alone. The outer part of the hair is quite firm, while its interior is softer, and probably conveys the fluids by which it is nourished. The hair is more glossy in health than at other times.

8. Office of the nail? Of the hair? Give the illustrations.

8. The nail serves as a protection to the end of the finger, and also enables us to grasp more firmly, and to pick up small objects. The hair, too, is a protection to the parts it covers. On the head, it shields the brain from extremes of heat and cold, and moderates the force of blows upon the scalp. On the body, it is useful in affording a more extensive surface for carrying off the perspiration.

9. On what does the complexion depend? Light and dark races? Freckles?

9. Complexion.—In the deeper cells of the cuticle lies a pigment, or coloring matter, consisting of minute colored grains. On this pigment complexion depends; and, according as it is present in less or greater amount, occasions the difference of hue, that exists between the light and dark races of men, and between the blonde and brunette of the white races. Freckles are due to an irregular increase of coloring matter.

10. Influence of the sun? How illustrated? Jews?

10. The sun has a powerful influence over the development of this pigment, as is shown by the swarthy hue of those of the white race who have colonized in tropical climates. It is also well illustrated by the fact, that among the Jews who have settled in northern Europe, there are many who are fair complexioned, while those residing in India, are as dark as the Hindoos around them.

11. What is an Albino? Where are Albinos found?

11. An Albino is a person who may be said to have no complexion; that is, there is an entire absence of coloring matter from the skin, hair, and iris of the eye. This condition more frequently occurs among the dark races, and in hot climates, although it has been observed in almost every race and clime.

12. What are sebaceous glands? How do they act? Sebaceous glands of the face? How do they act?

12. Sebaceous Glands.—There are in the skin certain small glands, which produce an oily substance, called sebaceous matter. These glands are little rounded sacs, usually connected with the hair-bulbs; and upon these bulbs, they empty their product of oil, which acts as a natural and adequate dressing for the hair (4, Fig. 14). A portion of the sebaceous matter passes out upon the surface, and prevents the cuticle from becoming dry and hard. The glands situated upon the face and forehead, open directly upon the skin. In these, the sebaceous matter is liable to collect, and become too hard to flow off naturally.

13. Black points, called worms? Animalcules? Service performed by sebaceous matter?

13. These glands on the face and forehead frequently appear, on the faces of the young, as small black points, which are incorrectly called "worms." It is true, that occasionally living animalcules are found in this thickened sebaceous matter, but they can only be detected by the aid of the microscope. This sebaceous matter acts not only to keep the skin flexible, and furnish for the hair an oily dressing, but it especially serves to protect the skin and hair, from the acridity arising from the perspiration.

14. Perspiration? Sweat glands? Of what do they consist? Dimension of the tubes?

14. The Perspiratory Glands.—The chief product of the skin's action is the perspiration. For the formation of this, there are furnished countless numbers of little sweat-glands in the true skin. They consist of fine tubes, with globe-like coils at their deeper extremity. Their mouths or openings may be seen with an ordinary magnifying glass, upon the fine ridges which mark the fingers. These tubes, if uncoiled, measure about one-tenth of an inch in length. In diameter, they are about one three-hundredth of an inch, and upon certain parts of the body there are not far from three thousand of these glands to the square inch. Their whole number in the body is, therefore, very great; and, in fact, it is computed if they were all united, end to end, their combined measurement would exceed three miles.

15. What is sensible perspiration? Insensible perspiration?

15. The Sensible and Insensible Perspiration.—The pores of the skin are constantly exhaling a watery fluid; but, under ordinary circumstances, there is no moisture apparent upon the surface, for it evaporates as rapidly as it is formed. This is called insensible perspiration. Under the influence of heat or exercise, however, this fluid is excreted more abundantly, and appears on the surface in the form of minute, colorless drops. It is then termed sensible perspiration.

16. Components of perspiration? Upon what does perspiration depend? Amount of perspiration daily?

16. Water is the chief component of this fluid, there being about ninety-eight parts of water to two parts of solid matter. The quantity escaping from the body varies greatly, according to the temperature of the air, the occupation of the individual, and other circumstances. The average daily amount of this excretion, in the adult, is not far from thirty ounces, nearly two pints, or more than nine grains each minute.

17. What does perspiration set free from the blood? What other service does perspiration perform? Explain the process.

17. The Uses of the Perspiration.—Besides liberating from the blood this large amount of water, with the effete matter it contains, the perspiration serves to regulate the temperature of the body. That is to say, as evaporation always diminishes temperature, so the perspiration, as it passes off in the form of fine vapor, cools the surface. Accordingly, in hot weather this function is much more active, and the cooling influence increases in proportion. When the air is already charged with moisture, and does not readily receive this vapor of the body, the heat of the atmosphere apparently increases, and the discomfort therefrom is relatively greater.

18. Effect of interruption of excretion? What experiments are mentioned?

18. The importance of this excretion is shown by the effects that often follow its temporary interruption, namely, headache, fever, and the other symptoms that accompany "taking cold." When the perspiration is completely checked, the consequences are very serious. Experiments have been performed upon certain smaller animals, as rabbits, to ascertain the results of closing the perspiratory tubes. When they are covered by a coating of varnish impervious to water and gases, death ensues in from six to twelve hours; the attendant symptoms resembling those of suffocation.

19. Give the story in relation to the boy covered with gold foil.

19. It is related that, at the coronation of one of the Popes about three hundred years ago, a little boy was chosen to act the part of an angel; and in order that his appearance might be as gorgeous as possible, he was covered from head to foot with a coating of gold foil. He was soon taken sick, and although every known means were employed for his recovery, except the removal of his fatal golden covering, he died in a few hours.

20. Give the quotation. Perspiration?

20. The Importance of Bathing.—From these considerations, it is evident that health must greatly depend upon the free action of the skin. "He who keeps the skin ruddy and soft, shuts many gates against disease." When the watery portion of the perspiration evaporates, the solid matter is left behind on the surface. There, also, remain the scales of the worn-out cuticle, and the excess of sebaceous matter. In order to secure the natural action of the skin, these impurities require to be removed by the frequent application of water.

21. Ablution in warm climates? What advice is given?

21. In warm climates, and during hot weather, ablution should be more frequently practised. For a person in good health, a daily cold bath is advisable. To this should be added occasionally a tepid bath, with soap, water alone not being sufficient to remove impurities of a greasy nature. Soap facilitates this, by forming with such substances a chemical mixture, which is readily soluble in water, and is by it removed from the body.

22. Liebig's maxim? What further is added?

22. There is a maxim by the chemist Liebig, to the effect, that the civilization of a nation is high, in proportion to the amount of soap that it consumes; and that it is low, in proportion to its use of perfumes. In some degree, we may apply the same test to the refinement of an individual. The soap removes impurity; the perfume covers, while retaining it.

23. What is said about cold bathing?

23. The different kinds of Baths.—All persons are not alike able to use the cold bath. When the health is vigorous, and the system does not feel a shock after such a bath, a prompt reaction and glow upon the surface will show that it is beneficial. Where this pleasurable feeling is not experienced, but rather a chill and sense of depression ensues, we are warned that the system will not, with impunity, endure cold bathing.

24. What is said about warm bathing?

24. It should also be borne in mind, that the warm or hot bath cannot be continued so long, or repeated so frequently as the cold, on account of the enervating effect of unusual heat so applied to the body. For persons who are not in robust health, one warm bath each week is sufficient; this class should be careful to avoid every extreme in reference to bathing, clothing, and whatever greatly affects the action of the skin.

25. What is said about sea-bathing?

25. Sea-bathing is even more invigorating than fresh-water bathing. Those who cannot endure the fresh water, are often benefited by the salt-water baths. This may be accounted for, in part, by the stimulant action upon the surface, of the saline particles of the sea-water; but the exciting scenes and circumstances of sea-bathing also exert an important influence. The open-air exercise, the rolling surf, the genial weather, and usually the cheerful company, add to its intrinsic benefits.

26. What is said as to the time and manner of bathing?

26. Time and Manner of Bathing.—A person in sound health may take a bath at almost any time, except directly after a full meal. The most appropriate time is about three hours after a meal, the noon-hour being probably the best. For the cold bath, taken rapidly, no time is better than immediately after rising. Those beginning the use of cold baths should first try them at 70° Fahr., and gradually use those of a lower temperature. From five to twenty minutes may be considered the proper limit of time to remain in a bath; but a sensation of chilliness is a signal to withdraw instantly, whether at home, or at the sea-side. Two sea-baths may be taken daily; one of any other kind is sufficient.

27. Condition of the body when bathing? Direction, after bathing?

27. The body should be warm, rather than cold, when stepping into the bath; and after it, the skin should be thoroughly dried with a coarse towel. It is best to continue friction until there is a sensation of warmth or "glow" throughout the entire surface. This reaction is the test of the good effects of the bath. If reaction is still incomplete, a short walk may be taken, especially in the sunshine. It is very congenial, however, both to health and comfort, to rest for a short time directly after bathing, or to take some light refreshment. This is better than severe exercise or a full meal.

28. Bathing among the ancients? Baths of Rome?

28. Bathing among the Ancients.—The Romans and other nations of antiquity made great use of the vapor-bath as a means of preserving the health, but more particularly as a luxury. Their method was not unlike that employed in northern Europe at the present day. The public baths of Rome and other cities are among the grandest and most interesting monuments of ancient luxury and splendor; and from their ruins have been recovered some of the most beautiful works of art.

29. After the bath? Swimming among the ancients?

29. The Thermæ, as the baths of Rome were called, were of great extent, built very substantially, and ornamented at vast expense. They were practically free to all, the cost of a bath having been less than a cent. It is related that some persons bathed seven times a day. After the bath their bodies were anointed with perfumed oil. If the weather was fine, they passed directly from the Thermæ into the gymnasium, and engaged in some gentle exercise previous to taking the midday meal. Between two and three in the afternoon was the favorite hour for this ancient luxury. Swimming was a favorite exercise, and a knowledge of it was regarded as necessary to every educated man. Their common expression, when speaking of an ignorant person, was, "He can neither read nor swim."

30. The Sun-bath? The story of Pliny?

30. The Sun-Bath.—Some also were accustomed daily to anoint themselves, and lie or walk in apartments arranged for the purpose, with naked bodies exposed to the direct rays of the sun. There is an interesting allusion to this practice, in a letter of the younger Pliny to the historian Tacitus, describing the destruction of Pompeii by an eruption of Vesuvius. "My uncle," (Pliny the elder,) "was at that time in command of the fleet at Misenum. On the 24th of August, about one in the afternoon, my mother desired him to notice a cloud which seemed of unusual shape and dimensions. He had just returned from taking the benefit of the sun, and after a cold bath, and a slight repast, had retired to his study." Then follows a description of the destruction of Pompeii, and the death of the elder Pliny.

31. Benefit of the sun? Effect upon plants? Skin?

31. We may judge somewhat of "the benefits of the sun," by observing the unnatural and undeveloped condition of plants and animals which are deprived of light. Plants become blanched and tender; the fish of subterranean lakes, where no light enters, are undersized, and have no eyes; tadpoles kept in the dark do not develop into frogs; men growing up in mines are sallow, pale, and deformed. Besides the well-known effect of solar light in tanning the skin, it also makes it thicker and better able to resist exposure; though the complexion may be thereby injured, the health gains more than compensate for the loss of beauty. "To make good the loss of the lily, where the sun has cast his ray, he seldom fails to plant the rose."

32. Direction about clothing? Exposing limbs of children? Clothing, night and day?

32. Clothing.—In reference to clothing, we are far more apt, in our changeful climate, to use too little than too much. An aphorism of Boerhaave, worth remembering, if not of adopting, is, "We should put off our winter clothing on midsummer's day, and put it on again the day after." He also says, "Only fools and beggars suffer from the cold; the latter not being able to get sufficient clothes, the others not having the sense to wear them." The practice of exposing the limbs and necks of young children, for the alleged purpose of "hardening" them, is quite hazardous. It is not to be denied that some seem to be made tough by the process; but it is so only with the rugged children, the delicate ones will invariably suffer under this fanciful treatment. As has been stated before, the skin is constantly acting, by night as well as by day. It is therefore conducive both to cleanliness and comfort to change entirely the clothing on retiring for the night. The day-clothing should be aired during the night, and the bedding should be aired in the morning, for the same reason.

33. Cosmetics? Painters' colic?

33. Poisonous Cosmetics.—The extensive use of cosmetics for the complexion is a fertile source of disease. The majority of these preparations contain certain poisonous mineral substances, chiefly lead. Now, the skin rapidly absorbs the fine particles of lead, and the system experiences the same evil effects that are observed among the operatives in lead works and painters, namely, "painters' colic," and paralysis of the hands, called "wrist-drop."

34. Certain hair-dyes also contain lead, together with other noxious and filthy ingredients. These do not work as great harm as the cosmetics, since they are purposely kept away from the skin, but they rob the hair of its vitality. Eye-washes, too, are made from solutions of lead, and many an eye has been ruined by their use. They deposit a white metallic scale on the surface of the eye, which becomes a permanent obstruction to the vision.

QUESTIONS FOR TOPICAL REVIEW.

	PAGE
1. What are the characteristics of the skin, and what office does it perform?	41
2. What can you state of the structure of the skin?	41
3. Describe the cuticle and tell its use.	41, 42
4. Describe the cutis or true skin and tell its use.	42
5. What can you state of the nature and growth of the nail?	42, 43
6. Of the nature and growth of the hair?	42, 43, 44
7. Of the offices performed by the nails and hair?	44
8. How is the difference in complexion in different persons accounted for?	44
9. How is the presence of freckles accounted for?	44
10. How does Nature provide a dressing for the hair?	44, 45
11. What other service do the sebaceous glands perform?	45
12. State what you can of the perspiratory glands.	45
13. What is the difference between sensible and insensible perspiration?	46
14. State the uses and importance of perspiration.	46, 47
15. What impurities gather naturally on the skin?	47
16. Repeat what is said of the importance of bathing.	47, 48
17. When should we indulge in cold, warm, and sea bathing?	48, 49
18. What is the effect in each case?	48
19. What directions are given as to the time and manner for bathing?	49
20. What is related of bathing among the ancients?	49, 50
21. What is related to show the antiquity of sun-bathing?	50
22. What are the effects of sun-bathing?	50, 51
23. What directions are given in relation to clothing the body?	51
24. What can you state of poisonous cosmetics?	51, 52
25. Of hair-dyes and eye-washes?	52

CHAPTER IV.