a lake of Campania in Italy, near Baiae, famous among the ancients for its poisonous qualities. It is described by Strabo as lying within the Lucrine bay, deep and darksome, surrounded with steep banks that hang threatening over it, and only Averus, accessible by the narrow passage through which you fail in. Black aged groves stretched their boughs over the watery abyss, and with impenetrable foliage excluded almost every ray of wholesome light; mephitic vapours ascending from the hot bowels of the earth, being denied free passage to the upper atmosphere, floated along the surface in poisonous mists. These circumstances produced horrors fit for such gloomy deities; a colony of Cimmerians, as well suited to the rites as the place itself, cut dwellings in the bosom of the surrounding hills, and officiated as priests of Tartarus. Superstition always delighting in dark ideas, early and eagerly seized upon this spot, and hither she led her trembling votaries to celebrate her dismal orgies; here she evoked the manes of departed heroes—here she offered sacrifices to the gods of hell, and attempted to dive into the secrets of futurity. Poets enlarged upon the popular theme, and painted its awful scenery with the strongest colours of their art. Homer brings Ulysses to Avernus, as to the mouth of the infernal abodes; and in imitation of the Grecian bard, Virgil conducts his hero to the same ground. Whoever failed thither, first did sacrifice; and endeavoured to propitiate the infernal powers, with the assistance of some priests who attended upon the place, and directed the mystic performance. Within, a fountain of pure water broke out just over the sea, which was fancied to be a vein of the river Styx; near this fountain was the oracle: and the hot waters frequent in those parts were supposed to be branches of the burning Phlegethon. The poisonous effluvia from this lake were said to be so strong, that they proved fatal to birds endeavouring to fly over it. Virgil ascribes the exhalation not to the lake itself, but to the cavern near it, which was called Avernus or Cave of the Sibyl, and through which the poets feigned a descent to hell. Hence the proper name of the lake is Lacus Averni, the "lake near the cavern," as it is called by some ancient authors.

The holiness of these shades remained unimpeached for many ages; Hannibal marched his army to offer incense at this altar; but it may be suspected he was led to this act of devotion rather by the hopes of surprising the garrison of Putcoli, than by his piety. After a long reign of undisturbed gloom and celebrity, a sudden glare of light was let in upon Avernus; the horrors were dispelled, and with them vanished the sanctity of the lake: the axe of Agrippa brought its forest to the ground, disturbed its fleecy waters with ships, and gave room for all its malignant effluvia to escape. The virulence of these exhalations, as described by ancient authors, has appeared so very extraordinary, that modern writers, who know the place in a cleared state only, charge these accounts with exaggeration: but Mr Swinburne thinks them entitled to more respect; for even now he observes the air is feverish and dangerous, as the jaundiced faces of the vine-dressers, who have succeeded the Sibyls and Cimmerians in the possession of the temple, most ruefully testify. Boccaccio relates, that during his residence at the Neapolitan court, the surface of this lake was suddenly covered with dead fish, black and fanged, as if killed by some subaqueous eruption of fire.

At present the lake abounds with tench; the Lucrine with eels. The change of fortune in these lakes is singular: In the splendid days of imperial Rome the Lucrine was the chosen spot for the brilliant parties of pleasure of a voluptuous court: now, a slimy bed of rushes covers the scattered pools of this once beautiful sheet of water; while the once dusky Avernus is clear and serene, offering a most alluring surface and charming scene for similar amusements. Opposite to the temple is a cave usually styled the Sibyl's grotto; but apparently more likely to have been the mouth of a communication between Cuma and Avernus, than the abode of a prophetess; especially as the Sibyl is positively said by historians to have dwelt in a cavern under the Cumæan citadel.