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. [Illustration: _The 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. HELEN: But how does the bath room look?