HISTORICAL SKETCH OF THE PROGRESS OF DISCOVERY, AND COMMERCIAL ENTERPRIZE, FROM THE DEATH OF ALEXANDER THE GREAT, TO THE TIME OF PTOLEMY THE GEOGRAPHER, A.D. 150.--WITH A DIGRESSION ON THE INLAND TRADE BETWEEN INDIA AND THE SHORES OF THE MEDITERRANEAN, THROUGH ARABIA, FROM THE EARLIEST AGES. For several centuries after the death of Alexander, the impulse and direction of discovery and commercial enterprize continued towards the countries of the East. Of his successors, Seleucus Nicanor and some of the Ptolemies of Egypt prosecuted his plans of commerce with this part of the world with the most zeal and success. Seleucus, after the death of Alexander, obtained possession of those provinces of his empire which were comprized under the name of Upper Asia; he, therefore, naturally regarded the conquered districts of India as belonging to him. In order to secure these, and at the same time to derive from them all the political and commercial advantages which they were capable of bestowing, he marched into India; and it is supposed that he carried his arms into districts that had not been visited by Alexander. The route assigned to his march is obscurely given; but it seems to point out the country from the Hyphasis to the Hysudrus, from thence to Palibothra, at the junction of the Saone and the Ganges, or, perhaps, where Patna now stands. There is no good reason to believe, with some authors, that he reached the mouth of the Ganges. Seleucus was stopt in his progress by the intelligence that Antigonus was about to invade his dominions; but before he retraced his steps towards the Euphrates, he formed a treaty with the Indian king Sandracottus, who resided at Palibothra: and afterwards sent Megasthenes, who had some knowledge of the country, from having accompanied Alexander, as his ambassador to him. In this city, Megasthenes resided several years, and on his return he published an account of that part of India; fragments of this account are given by Diodorus Siculus, Strabo, and Arrian; and though it contains many false and fabulous stories, yet these are intermixed with much that is valuable and correct. He gives a faithful picture of the Indian character and manners; and his account of the geography and dimensions of India is curious and accurate. Some further insight into these countries was derived from the embassy of Daimachus, to the son and successor of Sandracottus; this terminated the connection of the Syrian monarchs with India which was probably wrested from them soon after the death of Seleucus. At the time when this monarch was assassinated, Pliny informs us, that he entertained a design of joining the Euxine and Caspian seas, by means of a canal; he was undoubtedly the most sagacious of the Syrian kings, and the only one who imitated Alexander in endeavouring to unite conquest with commerce.