A Handbook of Health. Woods Hutchinson
in the open street, or from the cans in the stores, will contain anywhere from a million to a million and a half bacteria to the cubic centimeter (about fifteen drops); and samples have actually been taken and counted, which showed five and six millions.
Such a splendid food for germs is milk, and so rapidly do they grow in it, that dirty milk will actually contain more of them to the cubic inch than sewage, as it flows in the sewers. Now see what a difference a little cleanliness will make! Good, clean, carefully handled milk, instead of having a million, or a million and a half, bacteria, will have less than ten thousand; and very clean milk may contain as low as three or four hundred, and these of harmless sorts. The whole gospel of the care of milk can be summed up in two sentences: (1) Keep dirt and germs out of the milk. (2) Keep the milk cool.
The inside of the bottle is thoroughly cleansed by the revolving brush.
Besides the germs of the summer diseases of children, which kill more than fifty thousand babies every year in the United States, dirty milk may also contain typhoid germs and consumption germs. The typhoid germs do not come from the body of the cow, but get into the milk through its being handled by people who have, or have just recovered from, typhoid, or who are nursing patients sick with typhoid, and who have not properly washed their hands; or from washing the cans, or from watering the milk with water taken from a well or stream infected with typhoid. It is estimated that about one-eighth of all the half million cases of typhoid that occur in the United States every year are carried through dirty milk.
The milk that spills or spatters over the hand drips back into the can and may seriously infect the main supply.
The germs of consumption, or tuberculosis, that are present in milk may come from a cow that has the disease; or from consumptive human beings who handle the milk; or from the dust of streets or houses—which often contains disease germs. The latter sources are far the more dangerous; for, as is now pretty generally agreed, although the tuberculosis of cattle can be given to human beings, it is not very actively dangerous to them; and probably not more than three or four per cent of all cases of tuberculosis come from this source. The idea, however, of allowing the milk of cows diseased from any cause to be used for human food, is not to be tolerated for a moment. All good dairymen and energetic Boards of Health now insist upon dairy herds being tested for tuberculosis, and the killing, or weeding out, of all cows that show they have the disease.
Cheese. Cheese is the curd of milk squeezed dry of its liquid (whey), salted, pressed into a mould, and allowed to ferment slowly, or "ripen," in which process a considerable part of its casein is turned into fat. It is a cheap, concentrated, and very nutritious food, and in small amounts is quite appetizing. But unfortunately, the acids and extracts which have formed in the process of fermentation and ripening are so irritating to the stomach, that it can usually be eaten only in small amounts, without upsetting the digestion. Its chief value is as a relish with bread, crackers, potatoes, or macaroni. In moderate amounts, it is not only appetizing and digestible, but will assist in the digestion of other foods; hence the custom of eating a small piece of "ripe" cheese at the end of a heavy meal.
It is well to have the quality and purity of the milk tested just before it goes to the consumer, but it is far more important that it should be examined by State Inspectors at the dairy farms.
CHAPTER V
THE COAL FOODS (Continued)
STARCHES
Sources of Starch. The starches are valuable and wholesome foods. They form the largest part, both in bulk and in fuel value, of our diet, and have done so ever since man learned how to cultivate the soil and grow crops of grain. The reason is clear: One acre of good land will grow from ten to fifteen times the amount of food in the form of starch in grains or roots, as of meat in the shape of cattle or sheep. Consequently, starch is far cheaper, and this is its great advantage.
Our chief supply of starch is obtained from the seed of certain most useful grasses, which we call wheat, oats, barley, rye, rice, and corn, and from the so-called "roots" of the potato. Potatoes are really underground buds packed with starch, and their proper name is tubers.
Starch, when pure or extracted, is a soft, white powder, which you have often seen as cornstarch, or laundry starch. As found in grains, it is mixed with a certain amount of vegetable fibre, covered with husks, or skin, and has the little germ or budlet of the coming plant inside it. It has been manufactured and laid down by little cells inside their own bodies, which make up the grains; so that each particular grain of starch is surrounded by a delicate husk—the wall of the cell that made it. This means that grains and other starch foods have to be prepared for eating by grinding and cooking. The grinding crushes the grains into a powder so that the starch can be sifted out from the husks and coating of the grain, and the fibres which hold it together; and the cooking causes the tiny starch grain to swell and burst the cell wall, or bag, which surrounds it.
Starches as Fuel. The starches contain no nitrogen except a mere trace in the framework of the grains or roots they grow in. They burn very clean; that is, almost the whole of them is turned into carbon dioxid gas and water.[7]
This burning quality makes the starches a capital fuel both in the body and out of it. You may have heard of how settlers out on the prairies, who were a long way from a railroad and had no wood or coal, but plenty of corn, would fill their coal scuttles with corn and burn that in their stoves; and a very bright, hot fire it made.
One of the chief weaknesses of the starches is that they burn up too fast, so that you get hungry again much more quickly after a meal made entirely upon starchy foods, like bread, crackers, potatoes, or rice, than you do after one which has contained some meat, particularly fat, which burns and digests more slowly.
How Starch is Changed into Sugar. As we learned in chapter II, the starches can be digested only after they are turned into sugars in the body. If you put salt with sugar or starch, although it will mix perfectly and give its taste to the mixture, neither the salt nor the starch nor the sugar will have changed at all, but will remain exactly as it was in the first place, except for being mixed with the other substances. But if you were to pour water containing an acid over the starch, and then boil it for a little time, your starch would entirely disappear, and something quite different take its place. This, when you tasted it, you would find was sweet; and, when the water was boiled off, it would turn out to be a sugar called glucose. Again, if you should pour a strong acid over sawdust, it would "char" it, or change it into another substance, carbon. In both of these cases—that of the starch and of the sawdust—what we call a chemical change would have taken place between the acid and the starch, and between the strong acid and the sawdust.
If we looked into the matter more closely, we should find that what has happened is that the starch and the sawdust have