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.

29. Milk.—Milk is the best food known. It contains just enough water, albumin, fat, sugar, and minerals. Babies and young mammals live on milk alone. A man can live upon four quarts of milk a day. In sickness, milk is the very best food for men, as well as for babies.

The albumin of milk becomes hard when the milk sours. This makes cheese. The fat of milk rises to the top. We call it cream. When cream is churned, the pure fat comes together in a lump. Pure fat of milk is called butter. Cheese and butter are both good foods.

30. Eggs.—Eggs are also good food. The white of an egg is almost pure albumin. The yolk is albumin and fat. Eggs have no starch or sugar. They are not a perfect food, for some sugar must be eaten. But they can be quickly digested and they produce a great deal of strength.

31. Meat.—Meat contains albumin and fat, but no sugar. Fish, oysters, and clams are like meat. They all make good food. Boys and girls should eat milk, eggs, and meat. These foods are the best to give strength to the body. Nearly all food from animals is more quickly digested and gives more strength than food from plants.

32. Bread.—White bread is a food made from wheat. The wheat is ground to flour. Flour is mixed with water, and yeast is added. The yeast makes a gas, and the gas puffs up the wet flour and makes it full of holes. The holes make the bread light. Then bread is baked. Rye or corn meal makes good bread. Cake, biscuit, and pancakes are much like bread. Sometimes in place of yeast, baking powder is used to make the bread or cake light.

33. Meal.—Oatmeal, corn meal, and cracked wheat and rice are sometimes boiled, and eaten with milk. Bread, biscuit, oatmeal, and corn meal are made from grain. All are very much alike. The cooking makes them look and taste different, but yet they are nearly the same.

34. Why we need grain food.—All kinds of grain have much albumin, but only a little fat. But all have a great deal of starch. By digestion the starch becomes sugar. Grain is a good food because it has starch or sugar. Animal foods have no sugar, so we eat grain food with them. The two together make the most nourishing food. Potatoes have a great deal of starch and only a little albumin. They also are good food with meat.

A person cannot live well upon plant food alone, for it has too much starch and sugar, and too little albumin and fat. We need nearly equal parts of albumin, fat, and sugar. A mixture of bread, meat, eggs, vegetables, and milk makes the best food.

35. Fruit.—Fruit, like apples, peaches, and plums all have sugar. They taste good, and give us an appetite for other kinds of food. They have little albumin or fat.

36. Salt.—There is enough mineral matter in all food, and we do not have to eat iron or lime or soda. But we do need some more salt. Even animals need salt. Salt makes food taste good, and helps its digestion.

37. Water.—Water is also a food, for it forms the most of our bodies. All food has water. Even dry crackers contain it. 38. Pure water.—Water in a well runs through the dirty earth, and yet is clear and pure. This is because sand holds back the dirt. But sometimes slops from the house, and water from the barn yard, soak through the soil until the sand is full. Then the well water will be dirty and poisonous. People are often made sick by drinking such water. In cities the dirt fills all the soil and spoils the water. So the water must be brought from the country in large pipes.

Water in lead pipes takes up some of the lead. Lead is a poison. You should let the water run off from a pipe a little while before you use it. Good water is clear and has no smell or taste. Dirty or yellow water, or water with a taste or smell, is not fit for use.

39. Tea and coffee.—Tea and coffee are steeped in water and used as a drink. The drink is the water. The tea and coffee are neither food nor drink. They cause the cells of the body to do more work, and at the same time they take away the feeling of being tired. They do not give strength to the body, but are like a whip and make the body work harder.

40. The appetite.—When we have so many kinds of food, what kind is best for us? The taste of food tells us the kind of food to eat. Bread and meat, and such plain foods, always taste good, and we never get tired of them. Sugar tastes good until we get enough. Any more makes us sick. More than enough sugar or starch is found in bread and potatoes.

If we can eat food day after day, without getting tired of it, the food is good for us. If we get tired of its taste, either the food is not good for us or we are eating too much. Bad tasting or bad smelling food is always dangerous.

We can tell how much food to eat by our hunger or appetite. We can always feel when we have enough. Then is the time to stop.

Sometimes we eat plain bread and meat until we have enough, and then sweet cake or pie is brought in. Then we have a false appetite for sweet things. If the sweet things had not made a false hunger, we should have had enough to eat. But the false appetite makes us want more, and so we eat too much, and sometimes get sick from it.

41. Intemperance.—Eating for the sake of a false appetite is intemperance. Drinking strong drink for the sake of its taste is a common form of intemperance. But eating too much preserves, pie, and candy is intemperance too, and can do a great deal of harm. A little pie, or pudding, or candy, is good, because we can eat our sugar as well that way as in bread. But we should eat only a little.

42. Food and Diseases.—If our food is dirty or is handled with dirty hands, or is put into dirty dishes, there may be disease germs in it. Our food should always be clean, and we should have our hands clean when we handle it or eat it.

Storekeepers sometimes keep fruit and vegetables out of doors where street dust may blow upon it. This dust is often full of disease germs. Flies may also bring disease germs to the food. If food is kept where dust and flies can get at it, we ought not to buy it.

WHAT WE HAVE LEARNED