But with the hundreds of muscles which we now possess, how multiplied are our motions! For you should recollect that not only the movements of the head, arms, hands, fingers, back, legs, toes, &c., are performed by these means, but also the movements of the very 'chest itself in breathing, unless, as is the case with some unwise or ignorant mothers, we confine the chest by tight clothing. More than all this, the curious processes of chewing and swallowing our food, and of speaking, singing, crying and laughing, are chiefly donenot without the aid of the teeth, it is true-by means of the muscles.

The muscles have other uses still, besides those of beauty and motion; but the reader is not prepared to understand what they are, till he knows more about the blood and the circulation. In describing the circulation of the blood, I shall be likely to make the matter plainer, by far-and with fewer words-than I could possibly do it in this chapter.

CHAPTER XI.

THE COVERING.-BOARDS AND SHINGLES.

The skin. Coloring of the skin. Change of color. The cuticle. Oil glands. Pores of the skin. Cleanliness. Hair and nails.

THE SKIN. I have already told you what cellular membrane is. Now the first layer of the covering of the house I live in-for there are three of these layers-consists of this membrane, in pretty large quantity, and as it were pressed firmly together. It has a closely interwoven fibrous appearance, all the fibres crossing each other in every direction, like the felt of a hat; and it is strong and elastic. It is called the cutis vera, or real skin.

This membrane, or real skin, is principally composed of an almost endless number of small blood vessels, running along and crossing each other in nearly every direction, together with nerves equally numerous, intermingled

with them. The nerves, however, seem to be enlarged on the surface of this membrane, and to form little rows of eminences, or pimples. These are seen plainest on the tongue, and on the balls of the fingers; but they exist, in small size, all over us. You cannot prick the skin with the finest needle in the world, without hitting at least one nerve and one blood vessel. For there would be pain in doing so; and this always shows that a nerve is wounded. A very little blood will also flow, which shows that you have hit a blood vessel.

This is that which, in the case of the ox, deer and other animals, makes leather. In tanning, currying and dressing skins, the cellular layer just now described, the layer which remains to be described, and the paint, are all scraped off, and nothing remains but the true or real skin—the layer now under consideration.

I do not mean to say here, however, that leather consists of nothing but this skin, for tannin, as the chemists call it, which is extracted from the bark of the oak or other trees, combines with the raw hide, to make most kinds of leather; but I mean that no animal

substance goes to form the leather, except this single membrane.

COLORING OF THE SKIN.-We come now to the color of the human body. For so far as I have already described the skin, the color is exactly alike in all people, black, red or white. Here, spread over the true skinthe part which forms the leather-on a thin, gauze-like membrane, called in books rete mucosum, and under the outside membrane not yet described, is a soft pulpy or jelly-like substance, containing the color. In the African, this pulpy substance is black; in the native American or Indian, it is red, or copper color; in the Asiatic it is yellow, and in the European, white. In mixed breeds-mulattoes, &c.-it is of course of the various colors which those mixtures exhibit.

I have sometimes been surprised to find how ignorant most people are on this subject of color. Some have never thought of it at all; others suppose that the whole mass of our bodies is darker or lighter, according to the indication of our faces; others suppose the color is in the blood; and others still that it is

in the true skin, or the part which forms the leather. But we see that none of these are right-that the skin itself, properly so called, is alike in the whole human race; that is, it would form leather of the same color in all; and that the color might be removed, though not without much pain, leaving one individual as white and as dark as another.

What good this color does is, I believe, unknown; or why all mankind could not just as well have been left wholly without it, and all have been really flesh-colored. In some parts of the skin, in the European race, there seems to be but very little of it. It is only on the cheek, and perhaps the lips, that the color seems to differ much from that of the real skin itself.

There have been many conjectures about the uses of this coloring matter, but there is very little true knowledge abroad concerning it. We know, indeed, that a dark skin, as it allows the heat of the body to escape more rapidly than a light one, renders a person cooler in hot weather, in hot climates; but it would be difficult to believe that this is the principal reason for its existence.