Ex´tract, a term to denote all that can be dissolved out of a substance by a specified menstruum, such as water, alcohol, ether, &c. In modern pharmacy the term is applied to two kinds of preparation from vegetables. One is got by digesting the plant in water or other solvent, and evaporating or distilling away the excess of solvent until the extracted matter is sufficiently inspissated. The other is got by bruising the plant in a mortar, separating the juice, warming it until the green colouring-matter separates, and filtering it off. The juice is next heated until the albumen coagulates, and again filtered. The juice is now evaporated to a
syrup, the green colouring-matter added and well mixed, and the evaporation is thereafter continued until the required concentration is attained. Extracts must be capable of being redissolved, so as to form a solution like that from which they were derived. Extracts are used in cookery, medicine, and the manufacture of perfumery.—Extract of Meat (extractum carnis) is a soft, yellowish-brown solid, or very thick syrup, which is employed as a portable soup. It is now manufactured on the large scale by processes proposed by Liebig.
Extradi´tion (Lat. ex, out, and tradere, to hand over), the act by which a person accused of a crime is given up by the Government in whose territories he has taken refuge to the Government of which he is a subject. Conventions have been entered into by Britain with almost all civilized countries for the apprehension and extradition of persons charged with particular offences, especially those of the most heinous stamp, such as murder, robbery, embezzlement, arson, rape, and piracy. The Extradition Act of 1870 makes special provision that no criminal shall be surrendered for a political offence, and that the criminal shall not be tried for any but the crime for which he was demanded. Other British Extradition Acts are those of 1873, 1895, and 1906. See International Law.—Cf. Sir E. Clarke, The Law of Extradition.
Extravagan´za, in music or the drama, a species of composition designed to produce effect by its wild irregularity and incoherence; differing from a burlesque in being an original composition and not a mere travesty.
Extravasa´tion (Lat. extra, beyond, and vas, vessel), an escape of some fluid, as blood or urine, from the vessel containing it. Blood extravasation, in contusions and other accidents, is when blood-vessels are ruptured by the injury, and the blood finds its way into the neighbouring tissues. In some accidents to the urethra and bladder extravasation of urine is a very serious occurrence.
Extreme Unction has been, since an early period, one of the seven sacraments of the Roman Catholic Church. It is performed in cases of mortal disease by anointing in the form of a cross, the eyes, ears, nose, mouth, hands, feet, and reins (in the case of males). It is administered after confession and the eucharist, and is believed to remove the last stains of sin. It can only be administered by a bishop or priest, and is not applied in the case of young children or excommunicated persons.
Exu´ma, Great and Little, two of the Bahama Islands. The former is 30 miles long and 3 miles wide, and has a good harbour. Pop. 3465.
Eyalet (ī´a-let), a former administrative division of the Turkish Empire, subdivided into sanjaks or provinces, and kazas or districts. It was ruled by a pasha, and gave place to the vilayet on the reorganization of the empire in 1871.
Eyck (īk), Hubert and Jan van, brothers, famous painters of the old Flemish school, born at Maaseyck, Hubert in 1366, Jan probably about 1385. They lived first at Bruges, whence the younger brother is called John of Bruges, and afterwards at Ghent, to which they removed about 1420. Here they executed the celebrated Adoration of the Lamb for the Cathedral of Ghent; a painting which, in its different parts, contains above three hundred figures, and is a masterpiece. It was in two horizontal divisions, comprising ten panels, of which only the two central ones remain at Ghent, the others being at Berlin. Hubert did not live to see it completed. He died at Ghent (1426), as did also his sister Margaret, who was likewise a painter (1431). Jan finished the work in 1432, and returned to Bruges, where he remained till his death, which took place in 1441, and executed several excellent pieces. His reputation became very great even during his lifetime, by his share in the introduction of oil-painting; the original invention of which has been incorrectly ascribed to him by many. Jan van Eyck also introduced improvements in linear and aerial perspective, and in painting upon glass. Three portraits by Jan van Eyck, The Scholar, The Man with a Turban, and Giovanni Arnolfini and his Wife, are in the National Gallery, London; the Madonna of the Chancellor Rollin is in the Louvre.—Cf. W. H. J. Weale, John and Hubert van Eyck.
Eye, the organ of vision, is an instrument presenting some analogy to a photographic camera. It is provided with a lens for focussing images upon a sensitive membrane called the retina. The walls of the globe of the eye are formed principally of two fibrous membranes: one white and opaque—the sclerotic (Gr. sklēros, hard)—which envelops two-thirds of the globe posteriorly; and the other transparent, and resembling a horny plate, whence its name, cornea (Lat. corneus, horny). The sclerotic is a tough fibrous coat, and is the part to which the phrase 'white of the eye' is applied. In the front of the globe the sclerotic is abruptly transformed into the transparent portion (the cornea), which is circular, and which forms a window through which one can see into the interior. A membrane, the conjunctiva, so named because it unites the eye to the lid, spreads over the anterior portion of the globe, and then folds back on itself and lines the internal surface of the eyelids. On the internal surface of the sclerotic is a vascular membrane called the choroid. This is essentially the blood-vessel coat of the eyeball. About the place where the sclerotic passes