Ἰνδικά 19.1: Arrianus Ind. 6, 2

19.1

Καὶ τόδε λέγει Μεγασθένης ὑπὲρ ποταμοῦ Ἰνδικοῦ, Σίλαν μὲν εἶναί οἱ οὔνομα, ῥέειν δὲ ἀπὸ κρήνης ἐπωνύμου τῷ ποταμῷ διὰ τῆς χώρης τῆς Σιλέων, καὶ τούτων ἐπωνύμων τοῦ ποταμοῦ τε καὶ τῆς κρήνης· (3) τὸ δὲ ὕδωρ παρέχεσθαι τοῖόνδε· οὐδὲν εἶναι ὅτεῳ ἀντέχει τὸ ὕδωρ, οὔτε τι νήχεσθαι ἐπ’ αὐτοῦ οὔτε τι ἐπιπλέειν, ἀλλὰ πάντα γὰρ ἐς βυσσὸν δύνειν· οὕτω τι ἀμενηνότερον πάντων εἶναι τὸ ὕδωρ ἐκεῖνο καὶ ἠεροειδέστερον.

There is in India a river called the Silas, named after the fountain from which it flows, on which nothing will float that is thrown into it, but everything sinks to the bottom, contrary to the usual law.