Part 23

THE CLOCK OF LIFE.

“Oh, did you ever think, my child, That in your body dwells A tiny clock, that verily All other clocks excels?

“It needs no key to wind it up, No oiling of the wheels, No jeweler to make repairs; With such it never deals.

“Near seventy ticks a minute is Its normal race to go; Just place your thumb against your wrist, And you will find it so.

“This little clock was made to be A faithful sentinel, To give alarm of any change Within its prison cell.

“If you are healthy, then its ticks Are even, full, and strong; By this you know that, in its cell, Nothing is going wrong.

“When sickness comes, it works so hard, And is so feeble, too, It can not keep the perfect time Its Maker meant it to.

“Now, would you help this little clock The best of time to keep? Then always mind the rules of health, And thus their blessings reap.”

—Mrs. Julia Loomis.

THE CARETAKER

AMY: Just see, mother! I have cut my finger. See how fast the blood runs out! Oh-h!

MOTHER: Suppose we let a drop fall on this glass and then try to find out what it is made of, what it does in the body, and about the different rooms it visits. You may ask questions and I will try to answer them; but first we will bind up the cut finger in this bit of soft cloth. We have already learned how blood is made, but we want to learn what it does for us.

Blood is made from the food you eat and the water you drink. If you eat good food it makes good blood. Bad food and drink make bad blood. It might be called the caretaker, or the housekeeper of the body. Without it your body-house would go to ruin; for the Bible says, “The life of all flesh is the blood.” After passing through the kitchen, serving room, and dining room, the blood enters a dark tunnel and comes to your heart.

HELEN: But what makes it such a bright red color?

MOTHER: Because it has millions of little red bodies called cor´pus-cles. Really it is a pale yellow, but there are so many of these tiny folk floating around that they make it look red, just as a river would if it were packed full of tiny red fishes, or as water would if you should fill a bottle with very small red beads and then cover them with water.

PERCY: But are all the cor´pus-cles red?

MOTHER: No; some are white, but there are many more red than white.

AMY: What do they look like?

MOTHER: You can not see them at all unless you should look through a mi´cro-scope. The red cor´pus-cles are shaped like a little biscuit with a dimple in the middle. The white ones keep changing their shape in a very wonderful way. First they are round, then square, then three-cornered, and they take on ever so many other shapes. There are several millions of these little red and white fellows in a single drop of blood.

ELMER: But you said it went through a dark tunnel to get to the heart. Please tell us about that.

MOTHER: The tunnel is round, like a tube, and I must tell you that these tubes are in every part of your body. Some are quite large, some are small, and some are so tiny that you could not see them if you should try. They are like a tree with its trunk dividing into large branches, and these into smaller ones, till at last they become little twigs. The largest tubes for carrying blood through the body are called arteries. The smaller ones are called veins. The arteries carry fresh, bright, clean blood to every part of your body-house. It bounds along with a hop, skip, and jump, as though it were in a hurry to get to work. The arteries have very strong walls, and, as I told you, the blood soon finds itself in the heart.

HELEN: Which room did it go into first?

MOTHER: When the blood is fresh and clean it goes into the top room on the left side. It keeps coming in until the room is filled full. Then the little folding doors open, and the blood is crowded into the lower left room, the doors fly back, and--

AMY: But please tell us about the doors.

MOTHER: They are made so that the blood could not get back into the top room if it wished; for they never swing but one way, and some small cords hold them in place. These doors are called valves. When the lower room is filled, the walls press together, and the blood is forced into the largest blood tube in the body, the walls of which are so very smooth, that the blood passes along with a merry bound. The tube keeps growing smaller the farther we go from the heart, and branches into many smaller tubes.

PERCY: And how far does the blood go?

MOTHER: Perhaps it first takes a trip through the trunk of your body, down through your right leg, and on to the end of your big toe. The tubes at last become very small, and there are so many of them that they are like a network of the finest lace. A hair would seem like a big rope beside them. They are so very tiny that you can not see them. Their walls are thinner than tissue paper, and they are so close together that you can not touch your skin with the point of a needle without touching some of them. When the blood comes to these tiny tubes, it does not travel so fast as at first, and as it passes along, the muscles pick it to pieces, take the part they want as food, and load the blood down with waste which they can not use. When they are so hungry, the blood is glad to feed them and give them the oxygen, which makes them warm.

AMY: Did it stay long in those little tubes?