The Care of the Skin by John Harvey Kellogg

Seventh-day Adventist Publishing Association · Battle Creek, Mich. · Nov 18, 1902

The Care of the Skin

By John Harvey Kellogg

J. H. KELLOGG, M. D.

THE outer covering of the body is remarkably adapted to its protection. When viewed with a microscope, its surface is found to be made up of several layers of horny scales, which form a protective layer that is a poor conductor of heat and electricity, but affords a considerable degree of resistance to the entrance of foreign bodies, the bites of insects, and the introduction of poisons. It also protects against the entrance of germs. Beneath this layer are found the active portions of the skin, glands, nerves, and blood vessels, by which are performed the various functions that are carried on by this remarkable organ.

Of the glands, there are two kinds; we may, perhaps, say three. They are the perspiratory, or sweat, glands, consisting of a long tube leading from the surface to the deeper layers of the skin, ending in a little coil. The walls of these tubes are filled with blood vessels. The number of sweat glands in the skin has been estimated to be two and one-half million, and the walls of their tubes, if spread out, would cover a surface of ten or eleven thousand square feet. These glands secrete water containing salt and various waste substances. Under certain conditions, the sweat may also contain a slight amount of acid. Under ordinary conditions these glands pour out perspiration upon the skin at the rate of about one and one-half ounces an hour. Heat and exercise may increase their activity to more than forty times that amount. It is even possible for a person to perspire one fifth of his weight in twenty-four hours.

There are found in the skin small glands which secrete fat. This is poured out upon the skin as a protective measure. Probably to some extent the fat glands also act as purifiers of the blood, by removing wastes.

Here and there in the skin are found little pockets, from which grow the hairs.

The skin is very rich in blood vessels, the capillaries of which, by a peculiar arrangement, are made to lie between bands of muscular tissue. These, under some circumstances, are able to contract and compress the vessels in such a way as nearly to empty them.

The Temperature Nerves

The skin is a most remarkable structure in the large number and variety of the nerves which it contains. It receives special nerves for its glands, others for its blood vessels, nerves which appreciate pain, pressure nerves, the tactile nerves, which enable one to recognize the location of any part which is touched, and the temperature nerves of two kinds — the so-called hot and cold nerves. In all, there are at least seven or eight different kinds of nerves in the skin alone. By the aid of the temperature nerves, the skin becomes, like the eye, an organ by which it is possible to recognize light. The skin may, in a certain sense, be considered an extended eye. Some lower animals possess no other eyes than their skins, which are, however, extremely sensitive to light. This function of the skin is quite generally overlooked. Its importance can scarcely be appreciated until we have learned something more of the nature of light, one of the most wonderful of all the forces with which we are daily in contact. A word further, however, in reference to the thermic, or temperature, nerves.

There are two kinds of temperature nerves, which can be easily determined by touching the skin with hot and cold points. It will be found that the hot points are felt at certain places, and the cold points at certain other places. Those parts of the skin which are sensitive to cold are not sensitive to heat, and vice versa. These hot and cold areas are, of course, very small, and can only be detected by very careful observation. The information communicated by the thermic nerves is relative rather than positive. An object is felt as cold when it has a lower temperature than the skin, or some other object which has just before been in contact with the skin. In this way, one hand may be made to report an object as warm, while the other hand reports it as cool or cold. Very hot and very cold objects are not felt as such, but give rise to impressions of pain. Temperatures near that of the body are said to be neutral, because they do not stimulate either the hot or the cold nerves. The skin is more sensitive to cold than to heat, and cold is more quickly felt than heat. Objects that are good conductors, and so transmit heat to the skin or withdraw heat from it, rapidly feel warmer or colder than other objects whose temperature is the same, but which are not good conductors of heat. The temperature sense becomes quickly fatigued. It is for this reason that water which is so cold or so hot as to be at first painful, after a few seconds can be readily tolerated.

Light, and Its Effect upon the Skin

Modern researches have shown that a sunbeam contains at least three different kinds of light rays; namely, heat rays, luminous rays, and chemical rays. When the ray of light is decomposed by a prism, as seen in the rainbow, the heat rays are found chiefly in the red portion, the luminous rays in the yellow portion, while the chemical rays have a violet color. There are also invisible heat rays and invisible chemical rays. All these different rays act upon the body through the skin, but in different ways. The thermic nerves are especially stimulated by the luminous and heat rays. The chemical rays without doubt act upon other nerves. So-called “sunburn” is produced by excessive action of the chemical rays, and is an inflammation rather than a burn. The browning of the skin produced by exposure to the sun is due to the action of the chemical rays. These are also the rays that are useful to the body photographer. For though invisible to the human eye, these rays are recognized by the eye of the camera. All these visible and invisible rays are associated with the sunbeam, and exert a powerful influence upon human beings, as well as upon animals and plants. The powerful stimulating effect of light is shown by its influence upon vegetation in the spring.

Unquestionably, the civilized portion of the human race suffer greatly because of their exclusion from the influence of the sun’s rays by thick and dark-colored clothing, and by dwelling so much indoors. This evil should be remedied, as far as possible, by out-of-door life and frequent exposure of as large a portion of the body as possible to the active influence of the sun’s rays, by swimming in the open air, by means of the sun bath, the air bath, and the sand bath. Every school, and when possible every home, should have connected with it a large out-of-doors gymnasium, in which the benefits of the sun’s rays may be enjoyed in the summer time. Sun rooms should also be connected with every home, where the beneficial effects of light may be enjoyed to the fullest extent possible, as one means of counteracting the deteriorating influence of civilized modes of life.

Skin Training

An enormous amount of time is devoted to the training of the hand, the eye, and the brain; but the training of the skin is seldom thought of. Nevertheless, a well-trained skin is more essential to health than almost any other kind of bodily culture. The neglect of the skin must be regarded as the foundation cause of a large number of chronic maladies. It may almost be asserted that a man who will keep his skin in a thoroughly healthy condition may defy almost any known disease. The experienced horseman knows very well the importance of attending to the skin of the animal under his care. A horse which has a hidebound skin, with the hair dry and rough, is by this fact alone known to be in a state of disease. A man whose skin is hidebound, with the hair dry and dingy, dull and lifeless in appearance, and harsh and brittle to the touch, shows by this fact that his whole body is in a state of disease.

A healthy skin is warm, slightly moist, smooth, reddens quickly when rubbed or exposed to the action of hot or cold water, is supple and elastic, perspires readily under exercise or the application of heat, and is free from pimples, eruptions, and discolorations.

To maintain this condition, the skin must be subjected to daily bathing and grooming. Horsemen rub and groom their charges daily. Wild and domestic animals left free in the field habitually groom themselves by vigorously rubbing against trees or other objects. Man, of all animals, neglects to groom himself, and this is especially true of civilized man; for, as is well known, the savage and half-civilized nations from time immemorial have practiced rubbing of the body as a means of maintaining health.