OLIVE. (Lat. olea.) A genus of trees belonging to the Diandria Monagynia class of plants. The Olea Europa -a has an upright stem, with numerous branches, grows to the height of twenty or thirty feet, and differs from most trees in yield ing a fixed oil from the pericarp instead of from the seed. The olive tree has in all ages been held in peculiar estimation ; and some authors have styled it a " mine upon earth." It was sacred to Minerva. Olive wreaths were used by the Greeks and Romans to crown the brows of vic tors; and it is still universally regarded as emblematic of peace. Tho olive flou rishes only in warm and comparatively dry parts of the world, as the south of France and Spain ; in Italy, Syria, and the north of Africa; and though it has been raised in the open air in this coun try, its fruit did not ripen. The fruit is a smooth oval plum, about three quarters of an inch in length, and half an inch in diameter ; of a deep violet color when ripe ; whitish and fleshy within ; bitter and nauseous, but replete with a bland oil. Olives intended for preservation are
gathered before they are ripe. In pick ling, the object is to remove and to pre serve them green by impregnating them with a brine of aromatized sea-salt; and for this purpose various methods are em ployed. But it is chiefly for the sake of its oil that the olive tree is cultivated. Olive oil is pale yellow ; its density is 9.10. When fresh, and of fine quality, it is al most tasteless, having only a very slight and agreeable nutty flavor. It is less apt than most other fixed oils to become vis cid by exposure, and hence is preferred for greasing clock and watch-work. It is largely used as an article of food. It is the principal article of export from the kingdom of Naples.