colspan="3">Whole-milk, whey.

    Milk powder (whole and skimmed). Vitamines[2]   Nuts, cereals (corn embryo, wheat embryo, wheat-kernel, rice (unpolished)).   Beans (kidney, navy, soy).     Cotton seed, peanuts, bread.   Cabbage, carrots, celery.     Cauliflower, onions.     Parsnips, potatoes.     Peas (fresh), spinach.     Rutabaga, fruit, grapefruit.     Orange, lemon, tomato, raisins.           Water soluble “C.”     Fruits: Orange, lemon, tomatoes (canned).     Tomato (fresh), grapefruit, limes, apples.     Vegetables: Spinach, lettuce, cabbage (raw).     Peas (fresh), onions, carrots, cauliflower.     Potatoes (to a less extent).     Whole-milk (to a less extent).

THE INDIVIDUAL FOODSTUFFS AND VITAMINE FACTORS

A study of the individual foodstuffs and vitamines will furnish the first link in the chain which constitutes our present knowledge of dietetics.

CARBOHYDRATES

In the ordinary mixed diet of man, the carbohydrates predominate, being not only the most abundant, but also the most economical source of energy. The term carbohydrate covers all of the simple sugars and those substances which can be converted into simple sugars by hydrolysis; the ones of special interest in this study are divided into three groups, known as, Monosaccharides (C₆H₁₂O₆); Disaccharides (C₁₂H₂₂O₁₁) and Polysaccharides (C₆H₁₀O₁₅).

Monosaccharides.—Glucose, Fructose and Galactose are substances whose monosaccharide molecules contain one sugar radical; hence they cannot be hydrolized to simpler sugars (sugars of lower molecular weight). Those constituting this group of sugars are all soluble, crystallizable and diffusible substances, which do not undergo changes from the action of the digestive enzymes, consequently these sugars will enter the blood stream in their original form, unless attacked by the bacteria which inhabit the stomach and intestinal tract. The monosaccharides are all susceptible to alcoholic fermentation. Each member of the group is utilized in the body for the production of glycogen and for the maintenance of the normal glucose of the blood.

Disaccharides.—Sucrose, Maltose and Lactose are substances yielding, upon hydrolysis, two molecules of simple sugar: each of these sugars is crystallizable and diffusible: all are soluble in water, and to a less degree in alcohol—sucrose and maltose are more soluble than lactose. When attacked by the digestive enzymes, these sugars are changed to monosaccharides.

Polysaccharides.—Starch, Dextrin, Glycogen and Cellulose are substances more complex in character than the above-mentioned groups. They are built up of many sugar molecules, which yield upon complete hydrolysis many molecules of simple sugar. The polysaccharides are insoluble in alcohol, and only soluble to a certain extent in pure water. Some members of this group swell and become gelatinous in the presence of moisture and heat; some become of a colloidal form in water, and will pass through filter paper; others remain unchanged.

A brief description of the various members of these different groups of carbohydrates will assist the nurse in the ways and means of utilizing them in the dietary to the best advantage.

Glucose, which is abundant in the juice of plants and fruits, and to a more or less degree in the blood of all animals (usually about 0.1%) occurs free in nature. This sugar is likewise obtained from many carbohydrates, either through the action of acids, or as the result of the digestive enzymes, and as such becomes the principal form in which the animal body utilizes the carbohydrates ingested. Under normal conditions the glucose in the blood is constantly being burned and replaced; it is only when the body loses to a greater or less degree the ability to burn the glucose that it accumulates in the blood, from which it must escape by way of the urine. There are times, such as when very large quantities of carbohydrates are eaten at once, when glucose will also appear in the urine; but under such circumstances it is generally found to be merely temporary, and for this reason, the condition is known as temporary glycosuria. As a rule, however, the surplus of glucose absorbed, whether it be eaten as such, or is found as the result of enzymic action upon the other carbohydrates, is converted into glycogen and stored in the liver and to a less extent in the muscles. Glycogen is readily reconverted into glucose, which is used by the body for the production of energy. It has been estimated that over half the energy manifested in the human body is derived from glucose, and it is in this form that the tissues of the body will ultimately make use of most of the carbohydrates in food. Practically all of the fruits, and many of the vegetables, are rich in this form of carbohydrate, but grapes contain more than any of the other fruits, while sweet corn, onions, and unripe potatoes contain appreciable amounts.

Fructose.—The second member of the monosaccharide group is more or less associated with glucose in plant and fruit juices, and is used like that substance for the production of glycogen in the body. Eaten as such, or produced as the result of digestive action upon cane sugar, fructose is changed into glycogen, chiefly upon entering the liver, and for this reason will not be found to enter largely into the blood of the general circulation.[3]

Honey is the most abundant source of fructose in nature.

Galactose.—This sugar, unlike the other members of this group, is not found free in nature, but it is produced as the result of hydrolysis of milk sugar, either by enzymes or by acids. Like glucose and fructose, galactose seems to promote the