=25. Too fast eating.=--When the food stays too long in the stomach or intestine it sours, or decays, just as it does outside of the body. This makes us very sick. When we eat too much, or when we do not chew the food to small pieces, the stomach may be a long time in digesting the food. Then it may become sour and make us sick. =26. Biliousness.=--When the food is poor or becomes sour, it is poorly digested. Then the liver has more work to do, and does not change the food to blood as it should. It also lets some of the sour poisons pass by it. These poison the whole body and make the head ache. We call this _biliousness_. The tongue is then covered with a white or yellow coat and the mouth tastes bad. These are signs of sickness. The stomach and liver are out of order. =27. Rules for eating.=--If we eat as we should, our stomach will digest its food. We must follow three rules. _First_, we must chew the food in the mouth until all the lumps are fine. Then the food will be ready for the stomach. _Second_, we must eat slowly. If we eat fast we cannot chew the food well. The stomach cannot take care of food if it comes too fast. We must swallow all of one mouthful before we put another into the mouth. _Third_, we must eat only at meal times. The stomach needs a rest. Even a little candy, or apples, or nuts will keep the stomach at work, and tire it out. A child needs to eat more often than his father. So, besides his meals, he should have something to eat in the middle of the morning and some more in the afternoon. But he should not be eating at all hours. He ought not to eat little bits just before dinner, for that spoils his meal. WHAT WE HAVE LEARNED 1. The stomach and intestine stir and rub the food, and mix it with juices. 2. The juices change albumin to a liquid, and starch to sugar. They also change fat to the form of tiny drops. 3. The digested food soaks through the sides of the intestine into the blood tubes. 4. The blood carries the food to the liver. 5. The liver changes food to blood. 6. Blood goes to all parts of the body and feeds the cells. 7. The liver keeps poisons from getting into the blood. 8. Water and minerals become a part of the blood without being digested. 9. When food is not well digested, the liver cannot make it into good blood. This makes us bilious. 10. If food is not soon digested it sours and decays. This makes us sick. 11. We can make food digest quickly by chewing it well and eating slowly. CHAPTER V FOODS =28. Kinds of food.=--The cells of the body need water, albumin, fat, sugar, and minerals for food. We sometimes eat sugar alone, and we drink pure water. But most of our food is a mixture of all five kinds of food. Food comes from animals and plants.