Part 27

MOTHER: Yes; just as soon as strong drink is swallowed, every part of the body tries to get rid of it. The alcohol in such drinks makes the thin walls of the lungs hard, so they can not make the blood clean, and they try to throw out the poison. Sometimes it causes that dreadful disease, consumption, which can not be cured.

HELEN: Don’t a great many people die of consumption?

MOTHER: Yes; it kills more people than any other disease; so every one should take good care of their lungs, and give them plenty of room to grow. They should also breathe pure, fresh air at all times.

ELMER: But you can’t squeeze the lungs. We must have room to breathe.

MOTHER: But we can squeeze the stomach and liver so that the lungs do not have room, and by stooping over when sitting or walking, we get round shoulders and narrow chests, and this causes the lungs to become small and diseased.

AMY: I once read how some people on a ship suffered for fresh air.

MOTHER: Please tell us about it.

AMY: One night when there was a storm the captain told the sailors to send the people down into a large room below deck so they would not be in the way. After they had gone, the doors were fastened, so they could not get out. When the storm was over, the sailors took a candle and opened the door, but when they went in, the candle went out. At last enough fresh air got in so the candle would burn. They found the poor people lying on the floor, and quite a number of them were dead.

MOTHER: I suppose they had no air to breathe only that which had been used over and over again, and as that was not fresh, it poisoned them so they died. We should learn from this sad story to keep the lungs well filled with good air; for the blood can not be well cleansed if it is impure.

HOW THE HOUSE IS HEATED

MOTHER: If you touch a stone, Amy, how does it feel?

AMY: It is cold.

MOTHER: Yes, wood, iron, glass, and all the things around us which do not have life, are cold. If you touch your head, how does it feel?

PERCY: It is warm.

MOTHER: We sometimes see a little glass tube called a thermometer, with figures telling us how warm or how cold the air is. Here is a smaller one that you may hold in your mouth under your tongue, Elmer, and we will see if it will tell us how warm the house you live in is inside. That will do. The glass says it is about ninety-eight degrees. How many degrees will the larger glass record on a hot summer day?

ELMER: It is very warm when it is over eighty or ninety in the shade.

MOTHER: Yet you see that inside the body-house it is nearly one hundred degrees, yet you do not feel too warm. Are all animals warm?

HELEN: If they are alive, they are. If their bodies are cold, we say they are dead.

MOTHER: Some birds and animals have more heat in their bodies than we do. The horse has one hundred degrees, the ox one hundred and one, the dog one hundred and two, the sheep one hundred and four, and the duck and pigeon have one hundred and eight. The bodies of some creatures, such as fishes and frogs, are much cooler than our own, and we call them cold-blooded. The frog has only seventy degrees of heat.

HELEN: But what makes us warm, mother?

MOTHER: Do you remember that we talked a good deal about our food as fuel not long ago?

PERCY: But, mother, fuel is something to burn, and there is no fire inside of us.

MOTHER: That is true in one way; but let us see if we can find out where the heat in our bodies comes from. It may be a little hard to understand, but we will try. Here is a candle. If lighted, it burns brightly. Now I will fasten a wire around it and lower it into this glass jar and cover it tightly. Now watch it. What is the matter?

AMY: It is going out. Now it just flickers and hardly burns at all. Why does it go out, mother?

MOTHER: Because all fire must have a part of the air called oxygen to make it burn. When the candle can have plenty of air, it burns brightly, but when shut up closely, where it soon uses all the oxygen, it will not burn at all. Now our bodies are much like the candle. We eat food, and when it is made into blood, it mixes with the oxygen we breathe, and as it goes round and round in the body, it makes heat. The difference between us and the candle is that the burning does not go on as fast in our bodies as in the candle, so there is no flame, and it would take much longer to make the same amount of heat. If you throw a piece of fat into the fire, it will burn. If you eat the fat, it will make just as much heat in your body, but it will last a long time.

PERCY: How queer to think we are burning, bit by bit, just like a candle!

MOTHER: Yes; just as long as we live, the fire is kept going.

AMY: But I shouldn’t think that blood going around with oxygen in it would keep us warm.