The true nut is the seed of trees and shrubs which stores the greater proportion of food material for nourishing the seedling in the form of vegetable oil. The nut is very largely a fuel food or heat producer, therefore among the primitive races, along the warmer belts of the earth's surface, the nut was not of so much importance, but in the northern or colder countries, where the body-heat meets with such powerful resistance from climatic environment, the nut is of equal, if not of more importance than fruits.

Nuts as heat producers.

Pine nuts.

There are a few miscellaneous articles of food that are classed as nuts, which do not belong primarily to this group.

In the following discussion I will take up the several varieties of nuts in the order of their general value as articles of human nutrition:

There are several species of pine seeds from many varieties of trees, and from many different countries. The Italian pine seed or nut, called in Italy "Pignon," and in this country "Pignolia," is the refined or cleansed nut, called by the writer "pro-toid" nut. This is a coined word given to it because it contains the highest percentage of protein of any other food that has yet been analyzed. The "pro-toid" nut contains 34 per cent protein, 47 per cent oil, 9 per cent carbohydrates, 4 per cent ash, and 6 per cent water. The relative proportion of nitrogen to energy is not so great as in some other food products, such as eggs, or skimmed milk. These contain a large per cent of water, so that the protoid nut, while containing pound for pound more nitrogen than any other known food, has a lower nitrogen factor than foods which do not contain so large a percentage of fat. This same rule will apply to all nuts. They are rich in protein, but because of the large amount of fat which supplies energy in its most condensed form, the nitrogen factor, which is the relation between nitrogen and energy, is often lower in many nuts than in grain. The chief advantage of protoid nuts over other varieties is in their softness, consequently they are more digestible, and more assimilable than any other specimen of the nut family.

Composition of the pine nut.

The nitrogen factor in nuts.

The pine nuts which grow prodigally in the western part of the United States are not so rich in protein as the protoid nuts, but in other respects are very excellent food. The annual crop of these is about one million pounds, but is variable, a full crop being produced only about every third year. They are harvested in a very crude way, chiefly by Indians, from the remote districts of New Mexico, Utah and California.

Almonds

The almond is a most desirable food. It contains 17 per cent nitrogen, and 54 per cent fat. The flavor is very agreeable, and the nuts, in digestibility, rank next to protoid nuts.

Pecans. Brazilnuts. White Walnuts

They may be substituted for each other in many dietaries.

The pecan, which is a species of hickory-nut, contains 13 per cent protein, and 70 per cent fat. It is a very delicious article of food, though somewhat inferior to pine nuts and almonds, in digestibility, and as a source of nitrogen.

Brazil-nuts contain 18 per cent protein and 66 per cent fat, and rank high as an article of body-heat and energy.

Soft-shelled or white walnuts are commonly known as "English walnuts," though they are chiefly grown in France and in California. These nuts contain 24 per cent protein, 63 per cent fat, and form one of the staple nut foods of both Europe and America.

Filberts or hazelnuts contain 15 per cent protein, and 65 per cent fat. They differ widely from the varieties hitherto named, and are less digestible. They should be masticated exceedingly fine, and should not be taken by one whose digestion is particularly weak.

Hazelnuts. Butternuts. Beechnuts. Cocoanuts

Butternuts are a species of walnut. They contain 27 per cent protein, 61 per cent fat, and rank in the dietary along with English walnuts and Brazil-nuts.

Beechnuts contain 22 per cent protein and 57 per cent fat. Owing to the difficulty of gathering or harvesting, these nuts have never become popular as an article of human food. They are in the grain class, therefore rank high as an energy-producing material.

The cocoanut is a product of the palm tree, and, while quite distinct from our nuts of the temperate climate, is a very valuable and abundant food, deserving more extended use. Cocoanut is about one-half fat, contains 6 per cent protein and 28 per cent carbohydrates. The milk of the cocoanut is an excellent article of food, and used by the natives in the tropics in many remedial and medicinal ways.

Value of pea-nuts and soy-beans.

Peanuts

Peanuts, which are so widely used as food, are on the boundary line between nuts and legumes. They were classed as peas by some of the early botanists, and as nuts by others. The name indicates the compromise that was made between the two theories. Another legume, which is largely used in Japan and China is the soy-bean. Both the peanut and the soybean are better balanced, and more nutritious than common beans and peas. They are similar in composition, and contain about equal quantities of protein and fat, some peanuts yielding as much as 48 or 50 per cent oil. Neither are palatable in their natural state, but both are very delicious when their starch content is converted into dextrin by-roasting. The Japanese have a method of preparing the soy-bean by a process of fermenting, which renders the proteid material very digestible. Soy-beans have not yet been introduced into this country, hence there will be little opportunity to use them, and they will, therefore, not be discussed here at length.

Legumes rich in nitrogen.