Part 25

MOTHER: No; and that makes me think to tell you something else about this wonderful caretaker. If we had a quart of blood and should let it stand awhile, it would become thick like jelly. But if you should take a bundle of twigs and keep stirring it round and round, it would not get thick at all. If you looked at your bundle of twigs after stirring the blood with it, you would find the twigs covered with a sticky substance. If you should wash them, you would wash away the red color, and would have left a soft, stringy mass all matted together.

HELEN: But what is it good for?

MOTHER: It is called fibrin, and if it were not in the blood, you would bleed to death if you cut yourself. So long as the blood stays in the body, the fibrin goes quietly with it wherever it goes; but if it begins to run away, as it did from Amy’s finger, the fibrin goes to work at once to cork up the place so it can not get out.

PERCY: How long does it take the blood to go from the heart through the body and back again, mother?

MOTHER: I am sure you will be surprised when I tell you that the heart sends it with such force that it will go to the farthest part and get back in from three to eight minutes, and some say it takes even less time than that.

ELMER: What! so quickly as that! It does not seem possible.

MOTHER: And though one-eighth of the body is blood, yet it will all pass through the heart in about the same time.

HELEN: How wonderful! But I don’t see how all these little things in the blood, called cor´pus-cles, can get through the tiny, hair-like veins, which are so small.

MOTHER: We can learn a useful lesson from them, and you would be pleased, I know, to watch them, if they were only large enough so you could. They seem to know just what they want to do, and where they ought to go. When the little veins are too small for more than one to go in at a time, they do not push or crowd one another. One row waits as politely as can be till the others have passed in, and then they follow. How wonderful it is to think of this river of life flowing round and round, and we feel nothing of it but the gentle tap, tap of the heart as it sends it bounding through every part of the body! Should it stop, we would die; for “the blood is the life.”

PERCY: But how did people find out that the blood goes around as it does?

MOTHER: A doctor in England, named Harvey, first discovered it. Before his time people thought air went around through the body in the arteries. Men have studied the subject since Dr. Harvey lived, and they keep learning more about it all the time.

AMY: Does water go into the blood, mother?

MOTHER: Yes; it very quickly finds its way there, and it is the same with strong drinks, such as beer and whisky. It only takes a very few minutes for anything we drink to get into the blood stream.

The walls of the veins and arteries are governed by the nerves of our telephone system. They let just the right amount of blood flow through them all the time. When alcohol gets into the blood, it puts the nerves to sleep, and so too much blood goes into the little veins. You know a man who drinks has a red face. If he drinks a long time, his nose gets so red that it is called a “rum blossom.” This is because so much blood goes to his nose that it becomes large and red. Alcohol also makes the walls of the arteries weak, so they sometimes burst open and the person dies.

Now that we have learned a few things about the blood, we must be careful what we give this care-taker of the body to eat. We have learned very little of what there is to know, and as you grow older I hope you will study and learn more.

THE BATHROOM

HELEN: I have been thinking of what you said about the blood being washed every time it made a trip to any part of the body. Where is the bath room in the body-house, mother?

MOTHER: It is a large double room, and it is found in the top part of the trunk, each side of the heart.

PERCY: Why, I thought that was where the lungs are.

MOTHER: So it is; and it is in them that the blood is made clean after every journey it takes through the body.

AMY: But is there water in the lungs in which to wash the blood?

MOTHER: No; and the blood could not be washed in water if there was. It takes air to wash blood. Let us try to learn how it is done; but first we will take a peep into the bath room. There are two ways to get in. One is through the folding doors, the way that our food goes to the kitchen; for you remember there are four or five doors back of the pink curtain. In this place the air finds a door standing wide open, and it passes through a passage, called the windpipe, which is about three-fourths of an inch wide, and about four and one-half inches long in grown people. After going through the windpipe it comes to two passages, leading to the two parts of the bath room. While we might call it a double bath room, yet it is really two rooms.

ELMER: That must be the right and left lungs.

MOTHER: That is right. But I must not forget to tell you that there is another way to reach the lungs, and that is through two little doors, always standing open, just above the folding doors which lead to the kitchen. The air finds a long, curved passage to go through, and this is much the better way to go, because if it goes in cold, it passes some places where it gets warm before reaching the bath room. You know it would be rather hard to wash clothes in cold water, and so it is much better to have warm than cold air in which to cleanse the blood.

HELEN: You mean it passes through the nostrils in the nose.

MOTHER: Yes; and another reason why this is the best way for it to go is because the air is filtered or strained through some little hairs, which do their best to keep any dirt or dust which may be in the air from going further. These passages open back of the pink curtain, and it goes down through the windpipe the same as though it had passed through the mouth.

PERCY: But I should think our food would go into the bath room instead of the kitchen.

MOTHER: It would, only that, as soon as it starts for the kitchen, there is a little trap-door which feels it coming, and it shuts down quickly over the air passage, so nothing can get through. Suppose the trap-door does not do its duty quickly enough, and food “goes the wrong way,” as we sometimes say, the person chokes and has a bad time till the food is out of the way. I once saw a fowl eating corn, and in some way a kernel got into her windpipe. She began hopping about in great distress, and died as quickly as though her head had been cut off. It sometimes happens that people are choked to death in the same way.