AMPSANCTUS, or AMSANCTUS (mod. Sorgente Mefita)  , a small lake in the territory of the Hirpini, so m . S.E. of Aeclanum, close to the Via Appia . There are now two small pools which exhale carbonic acid gas and sulphuretted hydrogen . Close by was a temple of the goddess Mephitis, with a cave from which suffocating vapours rose, and for this reason the place was brought into connexion with the legends of the infernal regions . Virgil's description (Aeneid, vii . 563) is not, however, very accurate .