# 1911 Encyclopædia Britannica/Nut

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​NUT (O. Eng. knutu, cf. Dutch moot, Ger. Nuss; allied with Gael. cno; it is not of the same form as Lat. nux), a term applied to that class of fruit which consists generally of a single kernel enclosed in a hard shell. Botanically speaking, nuts are one-celled fruits with hardened pericarps, sometimes more or less enveloped in a cupule or cup, formed by the aggregation of the bracts as in the hazel and the acorn. In commerce, however, the term has a wider application and embraces many fruits having hard woody indehiscent shells or coverings without reference to their enclosed seeds or kernels, besides leguminous pods, and even tuberous roots. A great number of nuts enter into commerce for various purposes, principally as articles of food or sources of oil, and for several ornamental and useful purposes. For the most part the edible nuts are very rich in oil, with only a small percentage of the other carbohydrates, starch, sugar, &c., and they also contain a large proportion of nitrogenous constituents. Thus possessing rich nutrient principles in a highly concentrated form, nuts are by themselves rather difficult of digestion, and the liability of many of them to become rancid is also a source of danger and a hindrance to their free use. Oleaginous nuts used for food are likewise employed more or less as sources of oil, but on the other hand there are many oil-nuts of commercial importance not embraced in the list of edible nuts.
On the following page is set out an alphabetical enumeration of the more important nuts, and of products passing under that name, used either as articles of food or as sources of oil.
There remain to be enumerated a number of nuts of commercial value for turnery and ornamental purposes, for medicinal use, and for several miscellaneous applications in the arts. These include:
The application of the term nut to many of these products is purely arbitrary, and it is obvious that numerous other bodies not known commercially as nuts might with equal propriety be included in the list. Most of the nuts of real commercial importance are or will be separately noticed, and here further allusion is only made to a few which form current articles of commerce, not otherwise treated of.
The bread nut of Jamaica is the fruit of a lofty tree, Brosimum Alicastrum. It is about an inch in diameter, and encloses a single seed, which, roasted or boiled, is a pleasant and nutritious article of food.
The souari or surahwa nut, called also the “Butter nut of Demerara,” and by fruiterers the “Suwarrow nut,” is the fruit of Caryocar nuciferum, a native of the forests of Guiana, growing 80 ft. in height. This is perhaps the finest of all the fruits called nuts. The kernel is large, soft, and even sweeter than the almond, which it somewhat resembles in taste. The few that are imported come from Demerara, and are about the size of an egg, somewhat kidney-shaped, of a rich reddish-brown colour, and covered with large rounded tubercles.
The pekea nut, similar in appearance and properties, is the produce of Caryocar butyrosum, growing in the same regions of tropical America.
The Jamaica cob nut is the produce of a euphorbiaceous tree, Omphalea diandra, the seeds of which resemble in taste the ordinary cob or hazel nut. The seed however contains a deleterious embryo, which must not be eaten.
Cola, kola or goora nuts are the seeds of Cola acuminata (Sterculiaceae) a tree native of tropical Africa, now introduced into the West Indies and South America. The nuts form an important article of commerce throughout Central Africa, being used over a wide area as a kind of stimulant condiment. The nuts, of which there are numerous varieties are found to contain a notable proportion of theine, as much as 2·13%, besides theobromine and other important food-constituents, to which circumstances, doubtless, their valuable properties are due.
Coquilla nuts, the hard inner portion (“stone”) of the palm, Attalea funifera, the piassaba of Brazil, are highly valued for turnery purposes. They have an elongated oval form, 3 to 4 in. in length, and being intensely hard they take a fine polish, displaying a richly streaked. brown colour.
​The marking nut, Semecarpus Anacardium, is a fruit closely allied in its source and properties to the cashew nut (q.v.). The marking nut is a native of the East Indies, where the extremely acrid juice of the shell of the fruit in its unripe state is mixed with quicklime and used as a marking-ink. The juice also possesses medicinal virtues as an external application, and when dry it is the basis of a valuable caulking material and black varnish. The seeds are edible, and the source of a useful oil.
Physic nuts are the produce of the euphorbiaceous tree, Curcas purgans, whence a valuable oil, having similar purgative properties to castor oil, is obtained. The plant is a native of South America, but is now found throughout all tropical countries.
Pine nuts are the seeds of several species of Pinus, eaten in the countries of their growth, and also serving to some extent as sources of oil. Of these the most important are the stone pine, Pinus Pinea, of Italy and the Mediterranean coasts, and the Russian stone pine, Pinus Cembra. The Pinus Sabiniana of California and P. Gerardiana of the Himalayas similarly yield edible seeds. These seeds possess a pleasant, slightly resinous flavour.
Ravensara nuts, the fruit of Agathophyllum aromaticum (Lauraceae), a native of Madagascar, is used as a spice under the name of the Madagascar clove nutmeg.
The Sapucaya nut, a native of Brazil, is seen occasionally in fruit-shops. It is produced by a large tree, Lecythis Ollaria, or “cannon-ball tree.” Its specific name is taken from the large urn-shaped capsules, called “monkey-pots” by the inhabitants, which contain the nuts. The sapucaya nut has a sweet flavour, resembling the almond, and if better known would be highly appreciated. It is, however, scarce, as the monkeys and other wild animals are said to be particularly fond of it. This nut, which is of a rich amber-brown, is not unlike the Brazil nut, but it has a smooth shell furrowed with deep longitudinal wrinkles.
Soap nuts are the fruits of various species of Sapindus, especially S. Saponaria, natives of tropical regions. They are so called because their rind or outer covering contains a principle, saponine, which lathers in water, and so is useful in washing. The pods of Acacia concinna, a native of India, possess the same properties, and are also known as soap nuts.