LETHE (i. e. oblivion), in the Greek mythology a stream in the nether world, a draught of the waters of which, generally extended to the ghosts of the dead on their entrance into Pluto’s kingdom, obliterated all recollection of the past and its sorrows.

LETO (i. e. the hidden one), one of the Titan brood, who became by Zeus the mother of Apollo and Artemis, and for whose confinement, in her persecution by Hera, Poseidon by a stroke of his trident fixed the till then floating island of Delos to the sea-bottom.

LETTER OF MARQUE, a commission to the captain of a merchant ship or a privateer to make reprisals on an enemy’s ships or property.

LETTERS PATENT, a document under seal of the government granting some special privilege to a person.

LETTRES DE CACHET (i. e. sealed letters), warrants of imprisonment, issued prior to the Revolution, sealed with the private seal of the king, in contradistinction from lettres patentees, which were sealed by the Great Seal of the kingdom.  See CACHET, LETTRE DE.

LEUCIPPUS, a Greek philosopher of the 6th century B.C., the founder of the Atomic theory of things, of which DEMOCRITUS (q. v.) was the chief expounder.

LEUCTRA, a village in Boeotia, to the S. of Thebes, where in 371 B.C.  Epaminondas and his Thebans overthrew the ascendency of Sparta.

LEUTHEN, a village in the W. of Breslau, in Silesia, where Frederick the Great defeated the Austrians with great loss in 1757.

LEVANA, the title of a book by Jean Paul on the education of children; title from the name of a Roman goddess, the protectress of foundlings.

LEVANT (i. e. the Rising), a name given to the E. of the Mediterranean and the regions adjoining by the western peoples of the Mediterranean.

LEVEE, a morning reception held by the sovereign or some one of high rank.

LEVELLERS, a party of violent red-hot Republicans, led on by John Lilburne, who appeared in the time of the Commonwealth, but were suppressed by Cromwell.

LEVER, CHARLES JAMES, a novelist, born at Dublin, was by profession a physician; author of a numerous series of Irish stories written in a rollicking humour, “Harry Lorrequer” and “Charles O’Malley” among the chief; was a contributor to and for some time editor of Dublin University Magazine; held ultimately various consular appointments abroad, and after that wrote with success in a more sober style (1806-1872).

LEVERRIER, URBAN JEAN JOSEPH, French astronomer, born at St. Lo; distinguished in chemistry before he devoted himself to astronomy; rose to eminence in the latter science by a paper on the variations in the orbits of the planets, and was led to the discovery of the planet Neptune from perturbations in the orbit of the planet Uranus; he indicated the spot where the planet would be found, and it was actually discovered a few days after by Galle at Berlin (1811-1877).