LAGO DI

AGNANO  , a circular lake, 5 M . W. of Naples, Italy . It was apparently not formed until the middle ages, as it is not mentioned by ancient writers; it was drained in 1870 . It occupied the crater of an extinct volcano, 4 M. in circumference . On the south bank are the Stufe di S . Germano, natural sulphureous vapour baths, and close by is the Grotta del Cane, from the floor of which warm carbonic acid gas constantly rises to a height of 18 in., the fumes of which render a dog insensible in a few seconds . It is mentioned by Pliny (Nat . Hist. ii . 93) . Remains of an extensive Roman building and some statues have been discovered close by .