We do not know how far back the use of writing extends with the Indians. According to the account of Nearchus, they wrote on cotton, beaten hard; other Greeks speak of the bark of trees, while native evidence teaches us that the leaves of the umbrella palm were used for the purpose. Modern enquirers are of opinion that the Indian alphabet is not an invention of the people, but borrowed from the Phenician.[189] As we have shown, the Phenicians reached the mouth of the Indus in the tenth century. But about this time, or perhaps before it, there existed a marine trade between the Indians and Sabæans, on the coasts of south Arabia. Granting the origin of the Indian alphabet from the Phenician, it is thus rendered more probable that it was taken from the south Arabian alphabet, which in its turn rose out of the Aramaic alphabet, than that it was borrowed directly from the Phenician. In the latter case we should have to presuppose a trade between Babylonia and India by means of the Persian Gulf (in Babylonia the Aramaic alphabet was in use beside the cuneiform in the eighth century B.C. at the latest) as a more probable means of communication than the voyages of the Phenicians to Elath, which had already been given up. But from whatever branch of the Semitic races the Indian letters may have been taken, the general use of them cannot be put much earlier than 800 B.C. The oldest inscriptions of the Indians which have come down to us, are those of Açoka, king of Magadha, and belong to the middle of the third century B.C. They exhibit a complete alphabetic use of writing, and the forms of the letters are not very different from those employed at a later time.[190]