Part 22

MOTHER: He wanted to know how your heart was working, so he felt your pulse. Sometimes when people are ill it beats very, very fast, and sometimes it moves more slowly than it should.

AMY: What is the pulse?

MOTHER: If I use any words that you do not understand you must ask what they mean. The pulse is the beating or throbbing of the arteries caused by the blood flowing through them from the heart. Have you noticed how the water sometimes goes in jerks as it is pumped through the hose pipe in the garden? It is that way with the heart. Each beat sends the blood through the arteries in jerks, and when we place our fingers on them, we can tell how fast the heart is beating. That is called the pulse.

AMY: Sometimes I think that I can hear my heart beating.

MOTHER: Each time it beats it makes two sounds, and they can be heard if the ear is placed over the heart. The doctor can tell by these sounds whether the heart is working all right.

PERCY: But I should think it would get tired out if it keeps at work all the time.

MOTHER: So it would if it had no rest. Every part of the body must rest. Between the heart-beats there is just a little rest, and, though the time is very short, yet if it were all put together it would amount to six or eight hours a day.

HELEN: If the heart beats sixty or seventy times a minute, I wonder how many times it beats in a day.

MOTHER: You may do a little figuring to find out. Seventy beats a minute, sixty minutes an hour, and twenty-four hours a day.

ELMER: I have it. It would be more than one hundred thousand.

┌─────────┐ │ 70 │ │ 60 │ │ ———- │ │ 4,200 │ │ 24 │ │ ———- │ │ 16800 │ │ 8400 │ │ ———- │ │ 100,800 │ └─────────┘

MOTHER: And this means hard work, too; for if all it does in twenty-four hours were done at once, it would be equal to lifting one hundred and twenty tons of stone one foot from the ground.

PERCY: Whew! I should think this was a powerful little force-pump, sure.

MOTHER: But what would you think of a man who made his heart beat six thousand times more in twenty-four hours, which means that it must lift seven tons more than it should?

Amy: But I thought the heart kept working of itself. Then how could any one make it do more?

MOTHER: By taking only two ounces of alcohol in a day the heart would be overworked as I have said. It would not only have its regular work to do, but it would do that amount extra to throw out the poison it finds in the blood; for it knows it is an enemy. See, I have taken the pendulum off the clock for a minute. Now what has happened?

ELMER: It ticks much faster, and will soon run down.

MOTHER: It is much the same way with the heart of a person who takes drink with alcohol in it. His heart beats faster; his face gets red, and he can think and talk fast. It is like an engineer putting on steam and sending his train at lightning speed down a steep grade. If nothing worse happens, he will find when he comes where the track is up-grade that his power is gone and he has wasted his steam. The clock runs fast with the pendulum off, but it soon “runs down,” we say, and it is the same with the boy or the man who drinks. There are nerves which act on the heart as brakes do on the train. They keep it steadily at work and do not let it beat too fast. There is another way that alcohol hurts the heart.

HELEN: Please tell us how.

MOTHER: It changes the strong muscle walls into fat. The heart grows larger than it should be, and becomes so weak that it can not send the blood over the body as it should. The man has hard work to breathe. He gets the dropsy and other ailments, and perhaps dies of “heart failure.”

PERCY: Does tobacco affect the heart, mother?

MOTHER: Yes; it makes its beat unsteady, and sometimes causes an illness which doctors call “tobacco heart.” It also makes it work harder than it ought.

AMY: What can we do to keep the heart well and strong?

MOTHER: Be sure to give it good blood to send over the body. You need not keep still for fear that you will break this curious little pump; for, like the engines in ships, it is made to be tumbled about. Boys and girls can run, jump, and swing, yet the little engine keeps on with its steady hub tub against the walls of the house, and we would hardly know it was there. Good, honest labor makes the heart work better, and sends the blood running swiftly to every part of the body. We say when we are cold that a brisk walk will “start the blood;” that is, the heart beats more quickly, and soon the whole body becomes warm. We might say that the heart is like a clock, as well as an engine. If I do not wind the clock, what happens?

PERCY: It runs down.

MOTHER: Does some one need to wind up your heart each day to keep it beating?

HELEN: Oh, no; it just keeps going itself!

MOTHER: God keeps it beating, sometimes for a hundred years, without our help. I read a little poem not long ago about the heart, which I will repeat for you:—