Regarding the relative digestibility of white and brown (whole wheat) bread there is considerable diversity of opinion, but in a series of experiments described by Dr. John B. Coppock, in the "Herald of Health," England, it was shown that in equal portions of 100 ounces, 1/4 ounce more of the white bread was digested, than of the brown; but the proportion of Proteids (muscle and tissue forming const.i.tuents) digested, was as follows: white bread, 85 1/2 ounces; brown bread, 88 3/4 ounces, or 3 1/4 ounces more nutrition obtained from the brown bread than from the white. In any event, we are forced to the conclusion that as an article of food, bread has. .h.i.therto had a value placed upon it to which it was not legitimately ent.i.tled.

Nature has designed alb.u.men as the staple of nutrition for man, and primarily, vegetable alb.u.men; hence fruits form as nearly as possible a perfect food, containing, as they do, this important const.i.tuent in addition to the advantages previously mentioned.

Nuts are an excellent article of diet, as they contain a large percentage of proteid (muscle-forming) substance, and fats--both in a state of almost absolute purity, but are somewhat deficient in starch.

To those who feel that they really cannot do without meat, nuts certainly offer the best subst.i.tute. There are preparations of nuts on the markets now, called nut-meats, but our advice would be, to eat all nuts without preparation, only being careful to masticate them thoroughly. The peanut is the first in rank for nutritive value, next comes the chestnut, and third, the walnut.

Our objection to nut-meats applies to all forms of concentrated foods, that is, that they do not give the digestive functions the proper amount of exercise. They do not afford sufficient opportunity for mastication, hence the food is not properly insalivated. And, again, in normal conditions, Nature demands a certain amount of bulk, that the digestive organs may have something to contract upon. It is the nature of the muscular structures to grow if exercised, and there is no reason to doubt that the stomach and intestinal muscles respond to this stimulus. Bulk is especially necessary in the intestinal ca.n.a.l, to supply a certain amount of irritative stimulation, for the purpose of exciting peristalsis. That is one reason why whole wheat bread is preferable to white, on account of the bran, which not only supplies the bulk, but favors elimination by its irritative action.

Before proceeding any further we would call attention to the following table, showing the nutritive ingredients in food substances, and their several functions. The ingredients are cla.s.sified in four divisions: 1, Proteids; 2, Fats; 3, Starches, or carbohydrates; 4, Mineral matters. This is the main cla.s.sification; but to enable it to be better understood, we subdivide it as follows:

Protein.

a. Alb.u.minoids: e. g. alb.u.men (white of egg); casein (curd) of milk; myosin, the basis of muscle (lean meat); gluten of wheat, etc.

b. Gelatinoids: e. g. collagen of tendons; ossein of bones, which yield gelatin or glue. Meats and fish contain very small quant.i.ties of so-called "extractives." They include kreatin and allied compounds, and are the chief ingredients of beef tea and meat extract. They contain nitrogen, and hence are commonly cla.s.sed with protein.)

Fats.

e. g. fat of meat; fat (b.u.t.ter) of milk; olive oil; oil of corn, wheat, etc.

Carbohydrates.

e. g. sugar, starch, cellulose (woody fibre).

Mineral Matters.

e. g. calcium phosphate or phosphate of lime; sodium chloride (common salt).

In this cla.s.sification, water is not taken into account, for the reason that it is not a true nutrient, although of vital importance to the body. Now, let us consider what ultimately becomes of these substances--how Nature utilizes them in the physical economy. Protein is used to build up the solid tissues of the body, the muscles and tendons. It is also a source of nutrition for brain and nerve substance, and partially serves as fuel. Fats simply form fatty tissue and serve as fuel to maintain the heat of the body, by combustion or oxidation. Carbohydrates mainly serve as fuel, owing to the large percentage of carbon they contain, which readily unites with the oxygen. The mineral matters, which are also largely obtained from water, are employed in the formation of bone, and are also utilized in the blood and in other ways.

Thus we see that each const.i.tuent of the food substance fulfills a specific purpose, and the secret of a correct and nutritious diet lies in the selection of such foods as will furnish the proper proportion of each const.i.tuent to serve the purpose for which it is designed. Any deviation from this rule must of necessity result in digestive disturbance, more or less, and although one or two digressions from the path of correct alimentation may not result in anything worse than a slight inconvenience, yet persistence in dietetic errors will inevitably terminate in physical demoralization.

Authorities differ as to the actual proportion the nutritive ingredients should bear to each other in the daily ration; but after comparing the statements advanced by different food experts. We think the following figures will represent a fair average of the various tables. The reader will see that 100 parts of carbo-hydrates is taken as the basis of calculation, the figures opposite the other ingredients representing the proportion they should bear to the basic figure.

Carbo-hydrates (carbonaceous material, starch, sugar, etc.), fat, and heat formers, 100 parts.

Proteids (nitrogenous material) muscle, tissue and brain formers 40 parts.

Fats (animal fats, b.u.t.ter, etc.), fuel formers 32 parts.

Mineral salts, 6 parts.

Water 670 parts.

With the above table in mind, it will be easy to select foods that will furnish, when combined, the proper proportion of each ingredient--that is--approximately, and to a.s.sist in the selection, we subjoin a condensed list of the more important articles of food, showing the percentage of each ingredient, as proved by a.n.a.lysis. We would call attention to the fact that animal foods may slightly differ in the ratio of the ingredients, owing to the food upon which the animal has been raised, and its physical condition; and, owing to peculiarities of soil, vegetable foods may differ in like manner, but for practical purposes it will be found sufficiently correct.

IN 100 PARTS.

*Lean Beef Proteids. 20.2 Starches. 0.0 Fats. 3.6 Salts. 2.0

*Fat Proteids. 16.9 Starches. 0.0 Fats. 3.6 Salts. 2.0

*Mutton Proteids. 17.1 Starches. 0.0 Fats. 5.7 Salts. 1.3

*Veal Proteids. 18.8 Starches. 0.0 Fats. 4.4 Salts. 0.5

*Pork Proteids. 14.5 Starches. 0.0 Fats. 37.3 Salts. 0.8

*Poultry Proteids. 21.0 Starches. 0.0 Fats. 3.8 Salts. 1.2

*Smoked Ham Proteids. 24.0 Starches. 0.0 Fats. 36.5 Salts. 10.1

*Mackerel Proteids. 23.5 Starches. 0.0 Fats. 6.7 Salts. 1.0

*Cod Proteids. 27.0 Starches.0.0 Fats.0.3 Salts.22.0

*White of Egg Proteids. 20.4 Starches. 0.0 Fats. 0.0 Salts. 1.6

*Yolk of Egg Proteids. 16.0 Starches. 0.0 Fats. 30.7 Salts. 1.3

*Cow's Milk Proteids. 4.2 Starches. 4.5 Fats. 3.7 Salts. 0.7

*Cheese Proteids. 28.0 Starches. 1.0 Fats. 23.0 Salts. 7.0

*b.u.t.ter Proteids. 2.0 Starches. 1.0 Fats. 85.0 Salts. 1.0

*Cabbage Proteids. 5.0 Starches. 7.8 Fats. 0.5 Salts. 1.2

*Asparagus Proteids. 1.9 Starches. 2.7 Fats. 0.2 Salts. 0.5

*Mushrooms Proteids. 2.5 Starches. 4.7 Fats. 0.2 Salts. 0.7

*Potatoe Proteids. 2.2 Starches. 21.8 Fats. 0.2 Salts. 1.0

*Sweet Potatoe Proteids. 1.0 Starches. 25.2 Fats. 0.2 Salts. 2.7

*Celery Proteids. 1.5 Starches. 0.8 Fats. 0.4 Salts. 0.8

*French Beans Proteids. 23.7 Starches. 55.6 Fats. 2.2 Salts. 3.7

*Lima Beans Proteids. 21.9 Starches. 60.0 Fats. 1.9 Salts. 2.9

*Green Peas Proteids. 6.3 Starches. 12.0 Fats. 0.5 Salts. 0.8

*Lentils Proteids. 24.8 Starches. 54.7 Fats. 1.8 Salts. 2.4

*Wheat Flour Proteids. 11.6 Starches. 71.0 Fats. 1.3 Salts. 1.6