THE TEARS. From a small gland, not unlike the gland which furnishes the saliva, or spittle, only much smaller, over the top of each eye, just within the socket, flows a small quantity of a clear liquid, and, by means of the eyelids, operates as a moist cloth would do, passed over a glass window. This liquid is carried over the whole surface of the eye, and keeps it constantly moist and clean. The superfluous liquid is then carried off through a very narrow passage, which descends from the inner corner of the eye, and is conveyed by a pipe or duct into the nose.

The little gland over the eye is called the lachrymal gland; the liquor which it furnishes to wash the eye is called the tears; and the tube through which the tears escape into the nose is called the lachrymal duct.

If this duct gets permanently stopped, as sometimes happens, the tears overflow the eye, and run down on the outside of the cheek, which causes much trouble. To remedy this evil, the surgeon is sometimes obliged to fix an artificial tube in such a manner as to convey the fluid into the nose, to be carried off as it should be.

THE EYELIDS.-The eyelids are to guard the tender eye from injury in various ways.

One of their uses is to keep off the too strong light of the sun. If our eyelids were cut off, if it did no other harm, I am sure we should soon become blind. Those people who let the full blaze of a candle, or lamp, or bright fire, shine on their eyes, run a great risk of injuring their sight; but they are sometimes a great many years in finishing the work of making themselves wholly blind.

Besides veiling the eyes during sleep, another use of the eyelids is to ward off small bodies from the eyes, as sticks, chips, stones, &c. The power of the eye is wonderful in this respect. It will sometimes close so suddenly as to shut out an object which could hardly have been seen, just as if it felt it coming before it arrived. It does not always close quick enough, however; for blacksmiths, stone-cutters, cutlers, &c. sometimes have their eyes more or less injured.

THE EYEBROWS AND EYELASHES.-The eyebrows serve as a sort of defence to the eyes, by catching a part of the dust that would

otherwise fall into them.. Perhaps they may have other uses than this; but I have not room to enlarge. I should like to describe the eyelashes, and mention their uses, and also speak of several other membranes, vessels, &c., connected with this wonderful organ, but the limits of a work like this forbid. I can only say that besides contributing to the beauty of the countenance, both the eyelids and eyelashes lend their aid in keeping off too strong a light, as well as in defending the tender organ beneath from injury.

REFLECTIONS.-I must not close this chapter without noticing the place in which the eye is situated. Some animals, as the snake, tortoise, &c., have the eyes set in the side, or rather in the upper part of the head, precisely where they are wanted; for they have no occasion to look downward. In general, those animals that cannot move the eye without moving the whole body, have this organ more prominent, and more to the side.

But man, without moving his body at all, can move his head in such a manner that though the eyes are fixed in the front part of

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the head, and in a deep socket, he can yet look in every possible direction. All things considered, his eyes are as happily placed as those of any other known animal; and they are much better guarded from injury. Their deep bony socket, the high ridge around it, the eyebrows, the eyelids, the eyelashes, and lastly, reason to direct us, and enable us to avoid danger, all conspire to guard the "apple of the eye," as it has been called, with great care; and, in this country, it is comparatively seldom that we meet with a person, young or old, who has not both eyes perfect.

CHAPTER XIII.

THE COVERING.-THE DOORS.

Description of the ear, externally and internally. Description of the nose. The mouth.

THE doors of the house I live in are the

mouth, ears, nose, &c. These I call doors for reasons which have already been given, and for others which will presently be seen.

THE EAR.-Some account of this has been given in treating of the bones. The reader has already been told that it is made for the admission of sound; that if there were no ear, we could hear no sounds, and that a part of this curious organ lies deep in the bones of the head.

There are, in fact, two great divisions of the human ear-the external and the internal. The external ear is what we see in the living