5. Aristobulus calls the river, which runs through Sogdiana, Polytimetus, a name imposed by the Macedonians, as they imposed many others, some of which were altogether new, others were deflections[1019] from the native appellations. This river after watering the country flows through a desert and sandy soil, and is absorbed in the sand, like the Arius, which flows through the territory of the Arii. It is said that on digging near the river Ochus a spring of oil was discovered. It is probable, that as certain nitrous, astringent, bituminous, and sulphurous fluids permeate the earth, greasy fluids may be found, but the rarity of their occurrence makes their existence almost doubtful. The course of the Ochus, according to some writers, is through Bactriana, according to others parallel to it. Some allege that, taking a more southerly direction, it is distinct from the Oxus to its mouths, but that they both discharge themselves (separately) into the Caspian in Hyrcania. Others again say that it is distinct, at its commencement, from the Oxus, but that it (afterwards) unites with the latter river, having in many places a breadth of six or seven stadia. The Iaxartes is distinct from the Oxus from its commencement to its termination, and empties itself into the same sea. Their mouths, according to Patrocles, are about 80 parasangs distant from each other. The Persian parasang some say contains 60, others 30 or 40, stadia. When I was sailing up the Nile, schœni of different measures were used in passing from one city to another, so that the same number of schoeni gave in some places a longer, in others a shorter, length to the voyage. This mode of computation has been handed down from an early period, and is continued to the present time. 6. In proceeding from Hyrcania towards the rising sun as far as Sogdiana, the nations beyond (within?) the Taurus were known first to the Persians, and afterwards to the Macedonians and Parthians. The nations lying in a straight line[1020] above these people are supposed to be Scythian, from their resemblance to that nation. But we are not acquainted with any expeditions which have been undertaken against them, nor against the most northerly tribes of the nomades. Alexander proposed to conduct his army against them, when he was in pursuit of Bessus and Spitamenes, but when Bessus was taken prisoner, and Spitamenes put to death by the Barbarians, he desisted from executing his intention. It is not generally admitted, that persons have passed round by sea from India to Hyrcania, but Patrocles asserts that it may be done.