ARETHUSA, a celebrated fountain near the city of Syracuse in Sicily, famous for the quantity of its waters, and the number of fishes it contained. Many fables were invented by the ancients concerning this fountain. They had also a notion that the river Alpheus ran under or through the waters of the sea, without mixing with them, from Peloponnesus to Sicily. Mr Brydone informs us, that it still continues to send forth an immense quantity of water, rising at once to the size of a river, but is entirely abandoned by the fishes it formerly contained in such plenty. At some distance from Arethusa is a fountain of fresh water which boils up very strongly in the sea, inasmuch that, after piercing the salt water, it may be sometimes taken up very little affected by it. This fountain Mr Brydone thinks the ancients were ignorant of, or they would not have failed to use it as an argument for the submarine journey of Alpheus. It is much more probable, however, that these large fountains owe their existence to Mount Ætna.