13. As the pens of geographers delineate it, the whole of the region which we have been speaking of is thus divided. From the north to the Caspian gates it borders on the Cadusii, and on many Scythian tribes, and on the Arimaspi, a fierce one-eyed people. On the west it is bounded by the Armenians, and Mount Niphates, the Asiatic Albani, the Red Sea, and the Scenite Arabs, whom later times have called the Saracens. To the south it looks towards Mesopotamia, on the east it reaches to the Ganges, which falls into the Southern Ocean after intersecting the countries of the Indians. 14. The principal districts of Persia, under command of the Vitaxæ, that is to say of the generals of the cavalry, and of the king's Satraps, for the many inferior provinces it would be difficult and superfluous to enumerate, are Assyria, Susiana, Media, Persia, Parthia, the greater Carmania, Hyrcania, Margiana, the Bactrians, the Sogdians, the Sacæ, Scythia beyond Mount Emodes, Serica, Aria, the Paropanisadæ, Drangiana, Arachosia, and Gedrosia. 15. Superior to all the rest is that which is the nearest to us, Assyria, both in renown, and extent, and its varied riches and fertility. It was formerly divided among several peoples and tribes, but is now known under one common name as Assyria. It is in that country that amid its abundance of fruits and ordinary crops, there is a lake named Sosingites, near which bitumen is found. In this lake the Tigris is for a while absorbed, flowing beneath its bed, till, at a great distance, it emerges again. 16. Here also is produced naphtha, an article of a pitchy and glutinous character, resembling bitumen: on which if ever so small a bird perches, it finds its flight impeded and speedily dies. It is a species of liquid, and when once it has taken fire, human ingenuity can find no means of extinguishing it except that of heaping dust on it. 17. In the same district is seen an opening in the earth from which a deadly vapour arises, which by its foul odour destroys any animal which comes near it. The evil arises from a deep well, and if that odour spread beyond its wide mouth before it rose higher, it would make all the country around uninhabitable by its fetid effect. 18. There used, as some affirm, to be a similar chasm near Hierapolis in Phrygia; from which a noxious vapour rose in like manner with a fetid smell which never ceased, and destroyed everything within the reach of its influence, except eunuchs; to what this was owing we leave natural philosophers to determine. 19. Also near the temple of the Asbamæan Jupiter, in Cappadocia (in which district that eminent philosopher Apollonius is said to have been born near the town of Tyana), a spring rises from a marsh, which, however swollen with its rising floods, never overflows its banks.