NURSIA. See SABINES.

NUT. The term nut is 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, more or less enveloped in a cupule or cup, formed by the aggregation of the bracts. 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. The following is 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 Bread nut of Jamaica is the fruit of a lofty tree, Prosimum 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 (Rbizobolacem), a native of the forests of Guiana, growing 80 feet 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, Ompltalea 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 produce of Cola acuminate (Sterculiacm), 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 per cent., besides theobromine and other important food-constituents, to which circumstances, doubtless, their valuable properties are due.

Coquilla nuts, the large seeds of the palni, Attalea funifera, the piassaba of Brazil, are highly valued for turnery purposes. They have an elongated oval form, 3 to 4 inches 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, Curais 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.

The Pistachio nut is the fruit of Pistacia vera, L. (Anacardiacen). It is a native of Syria. Although a remarkably delicious nut and much prized by the Greeks and other Eastern nations, it is not well known in Britain. It is not so large as a hazel nut, but is rather longer and much thinner, and the shell is covered with a somewhat wrinkled skin. The small nut of Pistacia Lentiscus, L., not larger than a cherry stone, is also occasionally imported from Smyrna, Constantinople, and Greece.

Ravensara nuts, the fruit of Agathophyllum aromaticum (Laurace4 a native of Madagascar, is used as a spice under the name of the Madagascar clove nutmeg.

The Sapucaya nut, a Brazilian fruit, is seen occasionally in fruit-shops. It is produced by a large tree, Lecythis 011aria, 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 htts a smooth shell furrowed with deep longitudinal wrinkfes.

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 con,cinna, a native . of India, possess the same properties, and are also known as soap nuts. (J. PA.)