RAS-SEM, a city of Tripoli in Barbary, concerning which a number of fables were told by the Tripoline ambassador, all of which were believed in England and other parts of Europe in the beginning of this century. (See PETRIFIED-CITY.) Mr Bruce informs us, that it is situated about five days journey south from Bengazi; but has no water excepting one fountain, which has a disagreeable taste, and seems to be impregnated with alum. Hence it has obtained the name of Ras-Sem, or the fountain of poison. The only remains of antiquity in this place consist of the ruins of a tower or fortification, which, in the opinion of Mr Bruce, is as late as the time of the Vandals; but he says he cannot imagine what use they made of the water, and they had no other within two days journey of the place.—Here our traveller saw many of the animals called jerboa, a kind of mice; which, he says, seem to partake as much of the nature of a bird as of a quadruped.