the morning and play hard. You are breathing faster and deeper as well, as if th

or tea. It is so thin and light that we call it a gas. Indeed, I suppose it is pretty hard for you to believe that air is a real thing a

rom the whistle of a locomotive, and which we call steam. This is simply because air is so pure that it has no smell, and is so perfectly clear that we can see right through it. Almost the onl

for we die quickly when we cannot get it: it takes us only about

at it has sucked up from the food tube, and hundreds and hundreds of tiny red sponges called red corpuscles. These little sponges are full of air which they sucked up as the

ells must have food and air, just like any other animal. They eat the food the blood brings to them, and they take the air from the red cor

the wind blew it out; but how could the wind get through or under the jar? No, the glass keeps all the outside air away from the flame; and that is just the reason why it does go out. Unless

s. When we write about it, we use its nickname, the

have oxygen to burn their impurities, or waste; and if they don't get the oxygen

ee it, you can easily feel it. Blow on your hand. How warm your breath is! Touch your hand to your cheek. It is quite warm, too. If you run or play hard, you sometimes become so hot that you want to take off your coat. That is because your fires are burning

ing past them. If the cells did not do this, they would soon smother to death, just as you could not possibly live in a house

through the skin and stands in beads or drops upon it. That is the part we call perspiration, or sweat. The rest of it goes in the blood to another strainer ca

the lungs, where it can send off its "smoke" and then get fresh air to carry to the cells in the muscles. W

e choke-damp of coal mines, which suffocates the miners if the mine is not well ventilated; and the same gas that sometimes gathers at the bottom of a w

s, and should bring the fresh air into our houses and schools and shops. "Fill up" with it all you can on