OLIVE-TREE, or Olea, L. a genus of plants, consisting of six species, the principal of which is the Europæa, or Common Olive-tree.—It is a native of the Southern parts of Europe, especially Italy, France, Spain, and Portugal, where it is cultivated to a very considerable extent, on account of its fruit, from which the sweet or salad-oil is extracted; and which also, when pickled, forms an article of food. This tree, however, produces no fruit in Britain, even in hot-houses, and as it is planted only in tree gardens of the curious, we shall confine our account to the properties of olives, and to the oil obtained from them.
Olives possess, in their natural state, an acrid, bitter, and extremely disagreeable taste; which, however, is considerably improved when this fruit is pickled. The Lucca olives being smaller than any other, have the weakest taste; the larger ones, imported from Spain, are the strongest; but the most esteemed are the olives of Provence, which are of a middling size, and not so strong as those of Spain.—On account of the great quantity of oil they contain, all these varieties, if eaten by persons of delicate habits, are extremely hurtful, especially if taken by way of dessert, after a solid or heavy dinner.—Olives pay, on importation, the sum of 1l. 18s. 912d. per hogshead of 63 gallons.
As an article of food, olive-oil is preferable to animal fat; but it ought always to be mild, fresh, and of a sweet taste. It should not, however, be eaten by persons of weak stomachs; for, even in its mildest state, it produces rancidiiy and acrimony, which are extremely injurious to digestion.—Olive-oil is chiefly used in salads, and should always be consumed together with a large portion of bread, or with the addition of sugar, on account of its richness; as otherwise it requires a powerful and active bile to assimilate it to alimentary matter. It pays on importation the sum of 7l. 7s. 912d. per tun of 252 gallons.
Medicinally considered, olive-oil has lately been found an excellent preventive of the plague, when rubbed over the whole body immediately after the contagion is supposed to have taken place.—It is also beneficially employed internally for recent colds, coughs, hoarseness, &c. whether mixed with water into an emulsion, by means of alkalies, or with conserves or syrups into a linctus.—Lastly, considerable quantities are used in the preparation of plasters, ointments, &c. for external applications.