This lake is in the Compagna of Rome, near Tivoli, anciently called Albulus. It has what are called three floating islands, but they are only apparently so, being composed of bunches of sedges and bulrushes, glued together by the bitumen which swims on the lake, and the sulphur with which it is impregnated, and covered with sand and dust blown from the adjacent banks of the lake. These islands are from twelve to fifteen yards long, and the soil is strong enough to bear six persons, who, by a pole, may move to different parts of the lake. This lake has an outlet, whence its waters run, forming a whitish muddy stream, into the Teverone, the ancient Anio, emitting a vapour of a sulphureous smell as they flow. The ground near this rivulet, as well as on the banks of the lake, resounds with a hollow sound when a horse gallops over it. The water has also a petrifying quality, covering every substance that it passes over with a hard white stony substance. On throwing a bundle of sticks or shrubs into the lake, they will in a few days be covered with this stony crust; and this petrifying quality is even stronger in the rivulet that runs from it, than in the lake itself, and still increases till it falls into the Teverone. These small white incrustations that cover the pebbles in the bottom of the lake and rivulet, being somewhat like sugar-plums, are called Confections of Tivoli. Fish abound in the Teverone above and below Tivoli, till it receives the petrifying water; after which, during the remainder of its course to the Tiber, there are none.