All About Food
( Originally Published 1917 )
Of all the subjects capable of tempting the pen of the scholar, the professional man, and even the amateur, none has been more prolific or more exploited than that of food; and the number of works which treat of it, either in its entirety or along the lines of the different sciences which spring from it, are innumerable.
Some have discussed it from the economic, the philosophical, and the social point of view. Others have followed the more direct line of cooking and have made it the subject of wise scientific essays; while another class have sung and glorified the pleasures of the palate. What-ever may be the intrinsic merit of these works, they all point to the perfection of the art of good living, which plays an important part in the march of human progress and of civilization.
There can never be too many of such works, so varied are the kinds: and the more new ones produced, the greater will be the emulation, the more will a knowledge of the true scientific principles of food and feeding be disseminated and the more quickly and thoroughly will be popularized the correct methods and practices in the art of preparing and supplying food.
The question of the .proper nourishment of the body is wisely regarded as of the highest importance, since it alone, with rest of the wearied body, assures the suppleness of muscle, the vigor of the system, and the power of the mind. But-in order to properly realize the complex problem of food, it is highly necessary to know the good and bad qualities of food stuffs; to be able to select and to treat them according to the laws of hygiene and the rites of proper cooking; to know the proper value and the use of accessories and sauces, without which one can never attain to. the niceties of seasoning and taste.
To one who realizes the importance of proper preparation, and of sure guidance in these matters, there has always been the uncertainty of knowing where to find the precise, certain teachings; the processes sanctioned by the practices which, in association with scientific contributions, enable one to adjust the question of _food to tastes, ages, disposition, occupations, and climate.
The object of this work is to present, as far as possible, the sum of our knowledge of the art of maintaining good health by proper nourishment. An effort is made to present all that is worth knowing upon the subject by contributions from the pens of the highest medical authorities, famous chemical analysts, eminently successful housekeepers, and most excellent cooks.
It aims to be a sure guide and a reliable counsellor to the whole household economy, whether pretentious or simple. The facilities of an elaborate establishment, faultlessly equipped, are not of course to be compared to those of a remotely situated farmer's cottage; but the same knowledge, the same care ought to direct the preparation of the meals of those who inhabit the one or the other. The more a kitchen is ordered by hygienic laws, the more it rests upon demonstrated facts, the more it bases its formulas upon the gifts of professional students; the more will the art of cooking tend to become an exact science; and the hazard and chance of a wellcooked, nourishing meal be eliminated. The rapid advance of the applied sciences, and more especially that of chemistry, make it compulsory upon the one who holds the key of the health and welfare of the family to summon to her aid all of the forces for the satisfactory solution of the difficult problems relating to the wholesomeness of food.
It is especially. true that the person to whom is entrusted the choice and selection .of foods should not act blindly or unintelligently in the Matter. It is extremely important that such should know the nutritive value and digestibility of the diet of each individual, and what constitutes the proper ration of each, not in quantity, but in quality and kind.
As meats play such an important part in the household economy, they are made the subject of careful study.
Poultry and game are not less minutely studied: all of the preliminary processes are faithfully described by a demonstration of methods of dressing, carving, etc.
A good table, in the hygienic sense of the word, is the principal element of good health. It is, therefore, necessary to understand clearly what hygiene teaches us is a good table. Science is everywhere making rapid strides: In industry, commerce, and everywhere, the habits of chance, and of haphazard, are giving way, little by little, to scientific methods. The time has come when we are able to take ad-Vantage of the exact knowledge of foods and their- values which science has placed at our disposal. It is doubtless difficult in practice, except perhaps in large and fully equipped kitchens, to conform exactly to the scientific rules; but one is able to draw from them sufficient direction to enable one to proceed upon right lines and according to right principles in this most important of all matters.
The human body has been long ago likened to a lamp or a fire, which burns its food as a stove consumes the fuel with which it is supplied. It is a frequent poetic figure to speak of the " spark of life," or of the life which flickers, goes out, or kindles as a flame. And science will bear out this poetic metaphor, if one does not take it literally nor push the figure too far. Lavoisier, the eminent French chemist of the eighteenth century, proved conclusively that we are very like a lamp which consumes itself or as a fire that burns. The digestion supplies the necessary combustible material, and the breathing with the lungs is at once the draught which supplies the air to the burning fire and the chimney which carries off the gaseous products.
The heat furnished by this combustion of our food is that which keeps our bodies at the proper temperature. It has further been said that our bodies are not only fire which produces heat, but are at the same time machines capable of doing work,that they are steam-engines in which the combustible materials supply by their destruction both heat and work.
This is true with one exception: In a steam-engine that which burns and is destroyed is the fuel. The machine itself is made up of pieces of metal, the wear and tear of which are insignificant and almost of no account. But in the human body not only is the food consumed, but all the pieces of the body; the tissues, bones, and all its parts are used up and destroyed. It must, therefore, be plain that our food performs the double part of supplying the fuel for the human engine, and of continuously repairing its parts. Let us now consider the materials which are capable of performing this double duty in the economy of man.
The materials with which man repairs the losses which he continually sustains are derived by him from the tissues of plants and animals. Plants furnish either grains, such as the grains of cereals which give us meal and bread; or- the leguminous grains, as- peas, beans, etc.; with roots and tubers, as carrots; turnips, and' potatoes; with leaves, as lettuce, spinach, cabbage, cauliflower, etc.; or with fruits, as apples, pears, oranges, cherries, peaches, apricots, etc. From animals we derive three classes of products; the flesh, or meat with its accompanying fats; milk and its products, cheese and butter and eggs.
All of these foods are known as compound foods, because they are infinitely complex in their nature and chemical composition. Chemistry has determined beyond doubt that there are four types of simple foods derived from this complex mass of compound animal and vegetable foods.
1: The albumens.
2. The fats.
3. The starches and sugars.
4. The mineral matter, or salts.
Milk, the ideal food for the young, embodies in itself these four types of simple foods. And it is from an examination of it that. we can best come to an understanding of these types. If we allow the milk to stand for a time in a suit-able vessel, we will see the cream rise little by little to the top and form a yellowish layer or covering. This cream, when skimmed and churned, solidifies into butter, and here we see one of the types of simple foods, viz., fat. The skim milk when treated with rennet and subjected to pressure yields cheese, which is a simple food of the type of albumen. If the liquid which remains be slowly evaporated over the fire, we will procure yellowish crystals of sugar of milk, a type of the starches and sugars. Lastly, if the liquid be completely evaporated there will remain some solid matter much resembling the common salt of the household. This is. an example of the fourth type; the mineral matter or salt from the milk.
Chemical analysis of all of the elementary foods has shown that under the infinite variety of outward aspects which they present, whether meat, eggs, vegetables', or fruits, there are al-ways present one or more of the four varieties of simple foods, and these determine the character of the food.,
To estimate the value of an article of diet is to knew what it contains in the way of albumens, fats, starches or sugars, and mineral matter. Practically these four types represent all that is necessary to supply the wants of the human body. The fundamental problem of supplying proper food consists in combining these types in suitable quantities, and under the most favorable forms to satisfy the needs of each individual. It is to be remembered that though these simple types of food are present, yet they are in very variable proportions. Therefore, in order. to properly apportion a daily ration exactly suited to the needs of each person, it is necessary to combine the several compound foods, such as milk, bread, meat, vegetables, grains, and fruits, in such a way that the individual will obtain from them the albumen, fats, sugars and starches, and salts which are needed for the thorough nourishment of the body.
A thorough and intelligent knowledge of this important subject necessitates the consideration of
1. The simple foods.
2. The compound foods.
3. The manner in which it is necessary to combine these in order to make a diet; then to select the proper quantities of each, so as to form a ration for each person.
4. The manner of dividing that ration into the several meals.
The simple foods, which constitute the truly nourishing portion of what we eat, present themselves to us in a very great variety of external forms. One finds difficulty to appreciate, for instance, that the flesh of meat and the white of an egg are composed of exactly the same substance, viz., albumen. But whoever wishes to consider food in its true light as an article of nourishment must learn to ignore the external appearance. of the several articles and to regard them as so much of this or that simple food.
Albumen.—The type of this class of food is the white of an egg, which the Latins called albumen., and which is a solution of almost pure albumen in water. All of the animal and vegetable tissues contain some albumen in varying degrees; so it is found in all the compound foods. Meat is composed almost entirely of albumen of several sorts, combined one with the other. The albumen of milk has already been referred to as casein or cheese. Bread contains, in addition to a certain quantity of starchy food, an albuminous substance known as gluten,. which predominates in, the " gluten bread," or the whole-wheat bread so beneficial to diabetics. All of the vegetables and fruits contain also more or 'less albumen. Even the grass of the field upon which the cows feed contains the albutnen which is an indispensable article of food for all living beings.
All of the albuminous forms, whether the white of an egg or the semi-solid mass as found in meat, possess the quality of being coagulated by heat. By coagulation is meant the act of changing into a hard and elastic mass. This change occurs when a raw egg is changed into a hard-boiled egg, or when a piece of raw beef is changed into boiled or cooked beef by the action of heat.
Fats.—This class of foods is probably the most commonly known of the four types of simple foods. The major part of the fats which we eat are not disguised and hidden in the compound foods. They are added to the ration of food voluntarily. There are hardly any species of meats which are not accompanied by sufficient fat for their proper preparation as food. The majority of other foods, and especially the vegetables, require the addition of artificial fats, such as butter and lard, among the animal fats, and of olive oil, etc., from the vegetable kingdom.
Starches and Sugars.—Relatively very large quantities of these are eaten by us every day, as we shall see further on, whether they are found in the compound foods, or are added by ourselves to our dishes. Starch occurs largely in bread, in the form of flour starch or wheat starch; and in potatoes and other vegetables. These supply naturally the starch elements of our food. Arrowroot, tapioca, and sago are starchy foods extracted from the trunks of trees in tropical countries.
Sugars are furnished naturally by certain substances of vegetable origin, as the fruit-sugars from grapes, apricots, pears, peaches. etc., and as special products such as honey. Sugar is artificially prepared from sugar-cane and from beet-root. The starches and sugars are grouped together because, in the process of digestion, starches are changed into sugar.
This begins in the mouth under the action of the saliva and is completed in the intestines.
Salt and Mineral Matter.—This type of food is best represented by the table salt, the chloride of sodium of the chemist. It is added to our foods both in cooking and at the table. But this is not the only salt which we consume. We daily absorb a number of others which are absolutely necessary to our bodily welfare. These are found in all of the articles of which we partake. .They constitute the ashes which remain when articles of animal or of vegetable origin are burned. They include the sulphates, phosphates, and: chlorides of potassium, sodium, magnesium, lime, and iron. Salts are a part of our bodily structure, and are necessary to its growth and to the upbuilding of the wearing tissues. Iron is needed to repair and to supply the red corpuscles of the blood. Lime and the phosphates are necessary to the growth of . the skeleton. All of the salts which are needed for the growth and repair of the body are contained in the articles of our food, with the single exception of the common salt which we add as a seasoning. There is a peculiar physiological reason for salting our food. It is well known that among the wild animals only the grass-eating or herbivorous animals care for salt. The vegetables contain an abundance o the salts of potassium, and when they are taken into the system the potassium eliminates the sodium from the body and thus the amount of it is diminished and must be supplied artificially. In flesh-eating animals the supplies of potassium and sodium are more nearly even, and no elimination of the one by the other occurs.