Food; what it is and does

Preface

FOOD — WHAT IT IS AND DOES PURPOSE OF BOOK

Production of food and food-preparation are among the oldest occupations of human life. They are still most essential to human well-being. Cultivation and cooking of food have come down the ages into complex activities highly specialized and associated with concentrated commercial interests. Together these are coming under the direction of science and the regulation of the community.

Occupation with the needs created by living, is a common human pursuit, practiced with or without purpose or plan. Any continuation of life necessitates work. Advancing life requires intelligent work that includes the study of how to live constructively. That this may be, the study of food in school is now generally advised by all prepared to see its bearing upon both wholesome life and efficient work, and also how the understanding cooperation of humanity is needed in supplying and selecting what is of use for growth and health.

Civilization, in whatever stage it is at the time, is the environment into which each generation comes. But what the environment becomes in its supplies and practices is determined by humanity as it lives. Experience served as a guide to action until Science was born. Together Experience and Science inform humanity and can be forming to its environment, upon which its physical nurture depends.

The learner responds to the active aspects of learning with understanding. Personal experience in activity carries one not only into seeing facts but also into knowing their meaning. Cookery in its actual practice in choosing, combining, preparing food makes foodknowledge center in nourishment, in which its real significance lies.

But where cookery has not become a school course, while that subject is being ushered in — speed the day — or is being pursued

Hi only in its mechanical aspects, a study of food — diet — nutrition is needed. Such a school need for girls and also boys is met in this presentation of Food — What it is and does.

No community is longer wholly indifferent to youth's entering upon its mature functions and responsibilities, devoid of knowledge of what sustains and makes possible intelligent maintenance of abiding health and enduring energy. Even habits that secure healthful functioning of the body need the supplement of an intelligent, interested attitude toward information that has forming

power for race-growth.

EDITH GREER

New York

IV

CONTENTS IN GENERAL

RTPI

Plant Life and Plant Foods .... pp. 1-79

For Specific Subjects see p. vii

For Specific Subjects see p. 81

For Specific Subjects see p. 130

For Specific Subjects see p. t6o

Hygiene — Health — Sanitation . . 214-224

For Index see p. 225

ILLUSTRATIONS

Food Maps and Statistics Food Charts and Tables Diagrams and Interpretations

Meat Cuts and Carving Table- Laying and Equipment

New England Hearth Norwegian Bread-making Italian Kitchen and Well-head

Index records Specific Cuts under Illustrations

It*

Date

Papaiv

Banana

Plant life and Plant foods; Animal life and Animal foods; Food-Science Living — Industry — Commerce ; Home and Community Occupations

Certain needs are common to all physical life. It always

requires air, water, and food of some kind. In general,

however, the specific foods desirable for different persons

are as different as are the persons and their lives rj=\ Light on Life lightens labor in living a~| through Strength, Progress, Growth

VI

Markets — Human Foods — Human Nutrition 1-2 Vegetables — Starchy — Leguminous — Green 3-5 Comparison of Vegetables — Combination 6-7 Parts of Vegetables — Maturity — Preservation 8-1 1 Cooking — Caring for — Selecting of Vegetables 1 2-4 Plant- Production — Plant Foods — Grains 1 5-7 Cereal Maps and Data on Production 18-9 Cereals — Composition, Preparation — Grain Foods 20-3 Wheat — Milling — Flours — Breads — Bread- Making 24-8 Rising Agents — Yeast- Activity — Fermentation —

Leavens 2 9~3 1 Baking-Powder — Residues — Home-made Leavens 32-4 Flours — Home-used — Flour-Mixtures — Bread- Substitutes 35-7 Fruits — Cultivation — Preservation — Preparation —

Nuts — Production — Use as Food — Data and Maps 46-9

Oils — Acids — Spices — Flavorings — Condiments 50-5 Beverages — Tea — Coffee — Cocoa — Chocolate —

Sugar 56-64 Vegetation — Value — Life-Needs — Plant-Construction and Activity 65-8 Bacterial Life — Dangers — Significance — Development 69-70

CYCLE OF NATURE

Living Organisms — Products of Living — Life

Functions 7 r ~3

Food Cycle — Vegetable Cells — Starch Grains 74-6

Some World Crops in 19 12-19 13 77

Crop-Distribution — Maps and Diagrams 78-9

vii

MARKETS iftll HUMAN FOODS

Food Markets of the world show the foods of all climates, seasons, lands. Grain foods, vegetables, fruits, meats, dairy products are all seen and are all different. Yet they all contain most of the food substances needed to nourish humankind, but in such different proportions and combinations as to make great variety in Human Foods.

City markets everywhere are much alike in what they have, and they have most foods known to humanity. In town, village, hamlet is found only what is produced in the locality. It is these rather than the cosmopolitan markets that show the characteristic foods of the land. It is upon such foods that the majority of the inhabitants depend for nourishment, that is, must live, grow, and do their work.

Rural life may limit further what comes from elsewhere, but it usually can be made rarely rich in what may be freshly raised at hand. With its abundance of fresh air and often fresh spring water the country provides for health-giving physical living that cannot be so fully insured under any other conditions.

Human foods support the life of humankind. They differ from the foods needed by both animals and plants but include both plants and animals themselves. Whatever humanity can digest, that is, can make over into body-tissue Or otherwise use to aid in its living and working, is a human food. But all human foods are not equally desirable. Only those foods are valuable which do for the body what food needs to do to give the body health, energy, strength, endurance, and which do not do anything less helpful. Which foods these are varies somewhat with life-conditions.

VEGETABLE FOOD

HUMAN NUTRITION

Of what plants and animals make human foods and how they do this is considered later. The result of their food-manufacture is that human food is both vegetable and animal. Both serve in some respects # the same purpose in the body, while in others their use is different. Either vegetable or animal food would sustain life, but both together do so much better than either could. Vegetable food would do better alone than animal. Not a few persons do live upon it entirely. There are, however, reasons that make food-scientists doubt the advisability of an exclusively vegetable diet. But Science now advises that somewhat more than one half (at least .56) of the food of humankind be vegetable.

Plant food supplies most of the energy and endurance of the body in starch, sugar, and vegetable-oil foods ; also much of the body-heat, the food-bulk required for digestive activity, the salts needed for body-regulation, and the water used in living processes and food-utilization. Some vegetable food can also build up body-tissue as it needs repair or material for growth.

Vegetables, fruits, and seeds are of plant production. What these are like and where they come from, how they come, are prepared and used, are the food-facts that show what the food-supply brings to humankind as its vegetable food.

Looking back of the food as served is seen the life of the plant itself, also the work of those that bring it to humankind as a human food that will nourish when eaten. Seeking such facts and seeing them as factors controlling the sustenance of humanity is the purpose of studying Food — What it is and does.

What vegetable food is used in human living is learned from markets that show what foods are available and from science that finds what foods can be produced and supplied, also what kinds of food are needed.

(STARCHY) VEGETABLES

Plant food known generally as vegetables, fruits, grains, nuts, consists of various parts of the plant. The root, stem, stalk, leaves, flower, fruit, seeds all serve as human foods, but not all these parts of the same plant. Each vegetable food is the edible part of the plant from which it comes. Beets are roots ; celery is stem ; cabbage, leaves ; cauliflower, flowers ; tomato, fruit ; cocoa, seed. Different parts of some plants are edible at different seasons, as bean pods when young and beans when older.

Vegetables containing much starch are not edible raw, because starch cannot be digested uncooked ; such are potatoes. Vegetables containing a large percentage of starch are called starchy vegetables (see pp. 6, 9) to indicate this fact and designate in general what their use will be as a human food, for it is only their use in the body which makes them of importance as foods. Starchy vegetables keep well. They are therefore suitable for out-of-season use.

Starch develops in plants as they mature, as fat does in animals as they grow old. Starch eaten in excess of the daily need stores fat in the body as body-fat. Cooked starchy foods supply the body with energy that endures and body-heat.

Other constituents beside starch are present, too, in so-called starchy foods. These are water, mineral matter, often some sugar, fat in the form of oil, and a very complex substance called protein that always contains some nitrogen compounds. Protein is present in all living matter.

This constituent (protein) enables food to build up body-tissue as growth requires and living necessitates. Mineral matter serves in body-building too (the skeleton is largely mineral matter) and also aids digestion in various ways. Water does the latter too. Sugar and fat furnish heat-energy that is used more quickly than that supplied by starch.

VEGETABLES (LEGUMES)

One group of the starchy vegetables contains more protein than others. These are known as legumes. They are peas, beans, lentils. They have a power all vegetables do not share. Other plants take the nitrogen compounds they make into protein from the soil. Legumes have on their roots small tubercles or nodules in which there are bacteria that enable them to take free nitrogen directly from the atmosphere and store it in such plants for food use. Peanuts are also leguminous. Clover though not a human food is a leguminous plant, therefore has this power. By taking the free nitrogen of the air thus and making it into plant protein such plants can return the nitrogen in themselves to the soil for the plants that cannot take it from the air.

This has been one method of enriching the soil.

There is in many vegetables much woody fiber forming coverings and inner structure of the plant. This fiber is called cellulose. Cellulose, starch, sugar are all together termed carbohydrates in Food Science, because the elements of which they are composed are alike. These differ in their quantities and arrangement, and thus make the different carbohydrates — starch, sugar, cellulose. In general, carbohydrates supply heat-energy. Sugar is the carbohydrate most readily assimilated by the human system. Starch needs preparation before it can be utilized. Cellulose is only slightly digested, if at all, and then only from very young plants. There is little actual cellulose in human foods as eaten.

CONSTITUTION

(GREEN) VEGETABLES

" Green vegetables " is a term used to signify plant foods eaten fresh, usually raw and generally young. Industry is now canning these extensively. Transportation is carrying them from all climates to all cities. Both these practices result in some storing of such foods. The renewal of common interest in food-production is resulting in more distributed food-growth, hence less preservation of food and a fresher food-supply. This is most desirable for all food, but especially important for foods that have as one of their functions (that is, what they do) bringing refreshment through their own freshness.

Greenness suggests the freshness of newness. Green vegetation does this for life at large. Spring renews evidences of life. Summer verdure refreshes life. New plant foods renew diet. Green vegetable foods keep a diet fresh.

Though all such foods are not used uncooked, many usually are ; as lettuce, celery, radishes. They are most propitiously so used. Some are served simply as relishes, but it is as salads that their use is to be developed. Italy, the land of wealth in plant production, gives salads as a form of food-preparation of fresh green plants with olive oil. This is becoming the general food practice here and elsewhere. Encourage it.

These so-called green vegetables (see pp. 6, 8) contain much water, some cellulose, a relatively large percentage of mineral matter, and usually a distinctive flavor. Their value in human nutrition is their aid to the general maintenance of body-processes. They bring freshness, salts needed, and water. Cellulose (woody fiber) that is present in them can so stimulate the alimentary tract as to enable it to free itself of waste products ; though were cellulose itself retained in the body in excess it would endanger intestinal fermentations that prevent proper digestion of any food and so undermine health.

COMPARISON OF VEGETABLES

SUPPLEMENTING

There is no distinct separation between the different groups of vegetables called starchy and green. One group passes gradually into the other, sometimes a plant is used while young as green and as starchy when old, as beans. It is only the extremes of both that show marked differences, as do potatoes and tomatoes. The difference is, however, sufficient in their use in the body to make it advisable, when two vegetables are eaten together, to use one starchy and one green rather than two of either. See the table below.

Composition of SOxME Common Vegetables

Starchy Vegetables

Ash (indicates Mineral Matter)

% 75- 70.3 73- 80.3

79-9

8 7 .2

87.6 88.6 88.5 93-4

Potatoes White Sweet

Corn

Parsnips

Peas

Onions

Carrots

Beets

Pumpkins

% 20.6 27.4

19-5 16.1

7-9 3-9

% 2. 1.8

5- 1.4

3-9 2.2 1.4 1.1

2.4

% I.

I.I

•7

1 + .8- •7 + .6-

1.1 +

+ means slightly more than — means slightly less than

Green Vegetables

3-9

3-5 3-9 3-2

2.2

i.'i

2.4

.8

•9 2.1

1.4

.6

1.6

•4 +

•5 2.1

Cabbage

Celery

Lettuce

Cucumbers

Tomatoes

Hundredths over 5

have been called a

tenth ; under, were

dropped

Spinach

92.3

(Examine for general information only)

Adapted mainly from Olsen's " Pure Foods '

Add the solids of each together. Then write the vegetables in the order of the amount of water that these solids show each must have. Consider ash mineral salts. Compare the quantity of it in each with the amount of the other solids in the food. In what order should the vegetables be arranged to show this ?

DISTINGUISHING

DIFFERENCES IN VEGETABLES

Experience in eating teaches much about differences in vegetables that is not so practically learned otherwise. But science alone can explain what is experienced and give information that living could not disclose without such study. Examination of the chemical composition of foods shows that some are much alike which may seem different, also the reverse.

Though refuse is purchased it is not usually in foods as eaten. The water in the edible portion of food is consumed. Though it does not nourish, it serves in body-regulation.

Which vegetables should be used together to supplement one another ? Which should not be because they would duplicate one another ? Which of those that have much starch seem more nearly like " green " vegetables ? Are they in composition ? Parsnips and carrots are usually considered similar. See their composition. Note the similarity of the composition of pumpkins and cabbage.

For Complete Table of Food Composition, see Index.

Starchy, leguminous, and green vegetables have not only general differences but many specific variations within these groups. These alter the value of foods and their combination. Some foods nourish. Some make a diet palatable. Others by adding bulk promote peristalsis. Still others serve in regulation of body-fluids.

How foods are raised affects the dangers they may distribute. Celery, radishes, and such other ground- vegetables bring soil-dangers. All vegetables eaten raw, without skins to remove, as lettuce and salads, generally carry the dangers of soil fertilization, dust, and general handling. Their freshness need not be impaired to insure safety ; if washed in boiling water and plunged into cold, crispness is revived and the food safer.

PARTS OF VEGETABLES ^m AVAILABILITY

The waste in food is not always evident even when real.

Refuse in vegetables

None — spinach, tomatoes skinned, peas and beans dried. 7_i 5% — beans (7%) ; onions ( 1 0%) ; cabbage, cucumbers, lettuce ( 1 5%). 20-30% — potatoes (also sweet), parsnips, beets, carrots, celery (20%);

turnips (30%). 45-60% — green peas (45%); squash (50%); sweet corn (60%).

When it is remembered that water as well as refuse enters largely into the composition of vegetables as procured, it is realized that bulk is a significant characteristic of vegetable food.

Where the nutritive substances are in foods and how they are physically arranged affect their availability. Potatoes have an outer and inner skin. Both are richer in protein and salts than the flesh of the potato. Potatoes when peeled raw not only remove more nutrients than when peeled cooked, but in cooking permit the nutrients to be also dissolved out, as potato protein is in soluble form. Potato cooking-water, if the process is begun with cold water, contains -| of the protein. But if plunged in boiling water, even peeled potatoes lose less than T ^ ; unpeeled, only j^.

Slight nutriment (promote digestion) Palatability

Eggplant — T 9 7 water ; solids mainly starch. (Breading increases value.)

Cabbage — T 9 ^ water. Eaten raw retains nutrients. Cooked loses half.

Cucumbers — over T 9 ¥ water. Used only for palatability. No food-value.

Tomatoes — over T 9 ¥ water ; sugar over \ solids (sugar and protein soluble. Use juice therefore) ; some malic acid. Remove tomatoes from tin whenever not sealed air-tight.

Lettuce — over T 9 ¥ water. Valued for chlorophyll (green coloring matter). Contains iron.

Onions — valued for oils giving flavor. Stimulating to digestion.

Melons — solids J^-, mainly sugar, that with oils and acids gives the flavor.

USABLENESS

■m

CONSTITUENTS IN VEGETABLES

Protein and simpler compounds (of dietetic value) Tissue-Formation

Celery — T 9 g- + water. Valued for nitrogen compounds significant in diet.

Asparagus — over -^ water. More protein than many vegetables, also asparagin (nitrogen compound).

Spinach — over T 9 ¥ water; protein I to 4 carbohydrates. In potatoes protein 1 to 10 carbohydrates.

Beans — nearly i protein (more than in meat) ; less fat than other vegetables or cereals ; ash equal to that of cereals ; rich in potash and lime. String beans nearly T 9 ¥ water; as eaten, protein 2| per cent. Lima beans as eaten have more protein, as pods are discarded. Nutritive and aid digestion of other foods.

Peas — similar. Nutritious as vegetable or soup. Canned may be colored undesirably with copper salts.

Lentils — similar, but smaller. Nutritious.

Peanuts — similar to beans but much more fat. Like beans, peas, lentils (leguminous). All legumes digest slowly and require much intestinal work.

For starch, sugar, and some minerals (these furnish) Heat Energy

Potatoes — white : \ water ; \ starch, mainly ; salts, -| potash, \ phosphoric acid ; -^ protein. Sweet : more solids ; 6 per cent sugar ; keep less well (starch more stable than sugar).

Corn (sweet, green) — -| water ; \ solids (A starch, \ sugar, ^L protein when young). (Carbohydrates increase with ripening.)

Parsnips — over -| water ; 3 per cent sugar ; 3 per cent starch, exceedingly fine grains ; more fat ; salts, \ potash, A phosphoric acid (see potato above) ; more fiber, increasing peristalsis ; more flavor promoting palatability.

Beets — i the solids of potato, solids \ sugar.

Carrots — similar, but no starch ; sugar and pectose as carbohydrates.

Turnips — similar, no starch nor sugar ; pectose mainly as carbohydrates.

Squash — similar, with food-solids starch mainly. Pumpkins similar, but less solids. (Sugar is soluble, so dissolves in water. Baking prevents loss.)

(Facts stated above are in the main from Snyder's " Human Foods.") PLANT LIFE AND PLANT FOODS 9

VEGETABLE CHARACTERISTICS

MATURITY

Plants live. They grow from seeds. They develop the constitution of their plant family. Their developing is called maturing. They blossom, bear fruit, and produce seeds. This process repeated season after season is known as reproduction. Nature's method of continuing the life of vegetation is by physically renewing thus its products. Plant life gives definitely the processes of plant-living.

The readiness of plants for food-use and for reproduction of their kind is not usually the same, because in forming the seed the plant changes itself. The seed itself may be suitable food. When the seed is a human food the rest of the plant usually is not, as bean-pods. Cucumbers gone to seed are not good food, nor are potatoes raised for seed. When other parts than the seed are used for food, these are usually desirable when young or when just full-grown. Cellulose in young plants is tender, later woody. Green vegetables are therefore better young. Starch increases with maturity. Sugar when present does, too. Foods valued for these constituents are of course desirable only when these are produced in them.

Living substances in the main form human foods. Usually anything in food not derived from something that lives itself is not human food. Often such substances when introduced into food are not included in order to nourish the body, but to keep the food from such deterioration as would make its use impossible. It is only commerce overkeeping food and industry using inferior food that introduce non-food materials extensively into human food. Some condiments are of other than direct living origin. Common salt is, and is necessary to life.

Experience in living has taught humanity in which stage of development each plant is best as human food. This age-long habit is followed in choosing vegetable foods.

ALL VEGETABLES

VEGETABLE-PRESERVATION

Conditions under which different foods retain desirable quality indicate the necessities in preserving them. Preservation of food is such treatment of it as will keep it in suitable condition for human use. Green vegetables even in season are perishable. Prompt use is therefore the essential precaution against their deterioration.

Plants are living until they decay. They need the conditions of life, as air to breathe, though after they are plucked they need no longer the requirements for growth, as food. For seasonal use low temperature, complete cleanliness of receptacles and atmosphere, including protection from dust, are usually adequate attention in markets, shops, homes.

Green vegetables lose freshness, and wilt. Some lose sweetness ; fresh corn and peas do. Since they need to be kept in cool, dry air, they should be in a clean, wholesome, well-ventilated cellar or refrigerator. Slightly wilted vegetables revive by standing in water, but this may dissolve out their salts, also some protein and sugar. Lettuce wrapped in a moistened cloth and placed on ice remains crisp. If leaves discolor, remove at once. Vegetables should not be washed until they are to be used, as such moisture may hasten decay or mold-growth.

Starchy vegetables, such as potatoes and beets, need to be kept where it is cool and dry, and with little air in actual contact with them. They therefore keep well piled in cool, dark bins. The air of the room should, however, be fresh. Freezing and thawing changes vegetable-composition and should be avoided. Sprouting too renders a vegetable undesirable for food.

The regulation of moisture, light, temperature, is important because the degrees of these affect differently the growth of the various bacteria as well as the natural processes of decay in the plant itself.

COOKING VEGETABLES

IN GENERAL

Cooking food tends to break it up, thus preparing it for digestion. Cellulose in vegetables needs loosening and softening, so the nutritious substances associated with it may not be lost, because so fixed in this practically indigestible fiber that the digestive juices of the body do not reach them. Besides the aid of cooking, chopping vegetables fine assists in their digestion as often will treating a vegetable, as spinach, with vinegar. Thorough mastication always increases digestion.

Germs in food are generally destroyed or rendered harmless by cooking. This increases not only the safety of food but also the probability of undisturbed digestion.

Flavors of food are sometimes developed by cooking, but they may also be lost. In cooking vegetables the latter is the usual danger. Those delicately flavored, as cauliflower, cannot be cooked long or in much water. Those with strong juices often need several waters and longer cooking ; cabbage may. Vegetables cooked uncut retain flavor that cut they would lose. Cooking-water from vegetables contains many of their nutrients, especially salts, which have dissolved out. It should be used in dressings or soups. This necessitates thorough washing of all vegetables and removal of too strongly flavored parts. Palatability of food is affected by flavor. Digestion is stimulated by palatable food.

Young vegetables require less cooking than old. The difference in starch present partly accounts for this. Starch inadequately cooked makes work for the body by burdening it with undigested food. Thoroughly cooked starch does work for the body by providing it with energy. All vegetables need to be salted as they are cooked. Fresh vegetables require less cooking than wilted. The water lost must be returned in cooking ; the toughened fiber must be revived.

CARE — PREPARATION — USE

The structure of vegetables controls somewhat the manner of cooking. Rapid, hard boiling is needed for very much incased vegetables, as asparagus, especially if also delicately flavored. Baked food cooks in steam generated from the water in the food itself. The salts of foods are thus retained and the starch is more fully transformed for digestion.

In cooking, physical striLcture changes, germs are destroyed, flavor is preserved or modified, preparation for digestion begins.

The indigestible material in a food affects its nutritive value in several ways. The separation of it from the nourishing substances is an essential precaution in food-preparation. Cooking, grinding or chopping, masticating, dissolving, aid.

Raw food needs great care. Its freshness is of real value .

Vegetables should be clean themselves, kept so, and handled by no diseased persons. Decaying vegetables are unwholesome. The effect of unsoundness spreads beyond the parts seen as unsound. It rarely can be wholly removed by removing these. Germ-development is prevented by low temperature, pure dust-free air, and sunlight. Pure water too is protective against germs, so long as it remains pure.

Intelligent care of food is a health-help, also an economy.

What humanity has found suits its need is disclosed by the food-supply. This is general advice from race-experience. Living acquaints one with this. But only learning what each food is and does can teach when each should be used. Seasons and stages of development are given with the specific foods.

Grains are more closely related in composition to leguminous vegetables than to other vegetable foods. They serve similarly in the diet. Fruits, spices, nuts, differ somewhat from grains and vegetables and serve different food-purposes.

VEGETABLE-SELECTION

DIFFERENT VEGETABLES

Vegetables have value in human diet only as they serve directly or indirectly some food-need of humanity. The condition of vegetables affects their food-usefulness as much as does their kind. All kinds do not serve alike ; nor do all qualities. Inferior quality of the right kind for the purpose may even cause disease. All food should always be a health-help, strengthgiver, work-aid. To make it so, it must be selected with knowledge of the food-need and quality of the food eaten.

Selection of vegetables suitable for human use is a daily occupation of those determining the food of humanity. Food may through manipulation in preparation be made to appear well irrespective of its actual quality. This is to be avoided. It menaces health and may life. Safe and unsafe food, sound and unsound food, need to be easily distinguishable. Overripe tomatoes have developed in them acid not present earlier. This makes them undesirable and may dangerous. Preparation with seasoning, as in catsup, may make such tomatoes a palatable food, but does not overcome the result in that food of the overripeness of the tomatoes. Such food-preparation is to be discouraged by disuse.

Digestion is hindered by selection of unfit food. Malnutrition instead of nutrition results. Underripe food sometimes contains undeveloped substances not ready for human use. Green apples do. Foods picked green rarely ripen naturally. Choose those gathered ready for use, and use promptly. Overkept food may have lost what it was desirable it should retain or may have developed what it is essential it should not have. Such food is both more exposed to contamination and less able to resist it. Vegetables may carry human disease from the soil, receptacles, or persons. They may also be diseased themselves. This destroys their value as food.

PRECAUTION

PLANT-PRODUCTION

The human need for food is considered in Food Science, pp. 160-224. Precaution in production of vegetables is of great significance. Such food as green vegetables, being often eaten raw and being without covering to remove, such as fruit has, can carry disease from all sources. Fertilization of green gardens with waste products of living, as sewage, may propagate human disease and is to be avoided. Scrupulous cleanliness is essential with such foods. Even washing in boiled water vegetables to be eaten raw is advised if the purity of the water-supply is in any doubt.

Plants show their health and vegetables their quality readily upon observation. But skill in seeing comes only with looking and learning for what to look. Plants droop and die when not sound or cared for well. Vegetables wilt and decay when their vitality is waning. Such indications show the state of health of the food itself. The human disease germs a food may carry may have no apparent effect upon the food itself ; the danger is to those who eat food so laden. Precaution against dust everywhere, flies, insects, and any form of contact with illness or waste-products is too little practiced anywhere.