purposes; and there is scarcely a bone in the body but might be spared as well if not better than this.

THE FOOT.-The bones of the foot have a general resemblance to the bones of the hand, which I shall describe fully in another place. But they differ from those of the hand in several important particulars.

The foot is composed of twenty-six little bones, strongly fastened together by gristle, or ligaments. These ligaments yield, when we bear upon the foot, just enough to have it conform to the surfaces on which we tread. If the foot consisted of one solid bone, it would not yield or spring at all; and it would be liable to be broken when we jump or fall on our feet. Think how clumsy a wooden foot would be! And one of solid bone would be almost equally so.

ARCH OF THE FOOT.-The arching of the foot is a singular contrivance. It is, really, very much like the arch of a bridge upon its two abutments. I will explain the matter.

In the above engraving, the foot is not placed flat down upon the ground, but in the position which it has just setting it down. Then, as may be seen by the two lines drawn, it descends in a semicircle from the point of the heel. The lowest extremity of the heel and the ball of the great toe may be considered as the abutments of the arch, while the bones of the instep form the arch itself.

when we walk, and are

You may easily perceive, by lashing a strip of wood to the bottom of the foot, how awkwardly we should feel if we were obliged to walk with a flat foot. It is quite evident there would be no spring when we tread on it. We could hardly walk, run, leap or swim at all.

One thing more. The heel is not exactly under the leg, but runs back like a spur, and

Is fastened to the main body of the foot by a very firm but springy (elastic) joint. On this account, when we walk, (the heel being thus formed like a spur, and having a great deal of elasticity,) we put it down first, and the whole weight of the body does not come down with a jolt, as it otherwise would do, but more gently.

ITS CONTRIVANCE.-Taken altogether, the foot is a most admirable contrivance. It is, indeed, arched both ways; from the toes to the heel, and from side to side. It will help you to get a clearer idea of this arched structure, to step into the water with your bare foot, and then step immediately upon a dry floor, and find what sort of a track it will make. You see only a spot for the heel, and several spots for the toes and the parts of the foot near them. The middle part of the foot will scarcely touch the floor at all. There is, however, a difference in the form of feet. Some persons have flatter feet than others. All persons, however, have the soles of their feet apparently less arched than is shown by the engraving, on account of the muscles, tendons,

blood vessels, &c., which in a great degree fill up the hollow in the real foot.

I have said that this part of the human form is most admirably contrived; and it is so. When we examine the feet of the camel, the elephant, the horse, the dog, the cat or the bird, we are struck with the wisdom of the Creator, in adapting them to the kind of life they are destined to lead. The foot of the camel is so made, that it does not sink deeply into the sand on which it travels. The horse could not travel much in the deep sands of Arabia, his foot being more elastic, and made for firmer ground. It is, indeed, so very elastic, that those who shoe the horse find it necessary to make the shoe as narrow round the edge as possible, so that the iron may not press upon the softer and more elastic part of the foot, inside of the hoof.

THE ANKLE.-Between the lower ends of the tibia and fibula, and the bones of the foot, are seven short bones, not unlike those of the wrist in shape, but rather larger. Of these you will get a better idea, when I describe the bones of the upper extremities.

CHAPTER III.

MATERIAL OF THE FRAME.

Structure of bone. Shape of the bones. Description

of the bones. bones.

Growth of the bones. Vessels of the

You have already seen that the frame-work of the house I live in consists chiefly of bone. Before we go any farther, I ought to tell you how bones are constructed, and of what substances they are formed.

STRUCTURE OF BONE.-Sticks of timber are evidently full of little holes; for if you take a piece of wood, of several kinds which I could mention, and placing your mouth at one extremity, blow hard, you can force a little air through it, from end to end. This shows that there are little holes or tubes running lengthwise, all the way through. If you could blow hard enough, you might force air through any kind of wood. The philosopher and chemist,