A Treatise on Physiology and Hygiene Part 4

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 {44} interior is softer, and probably conveys the fluids by which it is nourished. The hair is more glossy in health than at other times.

[Sidenote: 8. Office of the nail? Of the hair? Give the ill.u.s.trations.]

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.

[Sidenote: 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.

[Sidenote: 10. Influence of the sun? How ill.u.s.trated? 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 ill.u.s.trated 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.

[Sidenote: 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.

[Sidenote: 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 {45} 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 pa.s.ses 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.

[Sidenote: 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.

[Sidenote: 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 gla.s.s, 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. {46}

[Sidenote: 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 circ.u.mstances, 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.

[Sidenote: 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 quant.i.ty escaping from the body varies greatly, according to the temperature of the air, the occupation of the individual, and other circ.u.mstances. 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.

[Sidenote: 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 pa.s.ses 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.

[Sidenote: 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 {47} "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.

[Sidenote: 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.

[Sidenote: 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.

[Sidenote: 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. {48}

[Sidenote: 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.

[Sidenote: 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.

[Sidenote: 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 cla.s.s should be careful to avoid every extreme in reference to bathing, clothing, and whatever greatly affects the action of the skin.

[Sidenote: 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 circ.u.mstances 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. {49}

[Sidenote: 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.

[Sidenote: 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 coa.r.s.e 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.

[Sidenote: 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. {50}

[Sidenote: 29. After the bath? Swimming among the ancients?]

29. The Thermae, 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 pa.s.sed directly from the Thermae 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."

[Sidenote: 30. The Sun-bath? The story of Pliny?]