It is remarkable also that in the enumeration of the exports of the island of Ceylon given by Arrian, no mention whatever is made of cinnamon. Nor does Cosmas refer to it. “I have searched,” says Sir Emerson Tennent, in his work on Ceylon, “among the records of the Greeks and Romans from the earliest time, until the period when the commerce of the East had reached its climax in the hands of the Persians and Arabians: the survey extends over fifteen centuries, during which Ceylon and its productions were familiarly known to the traders of all countries, and yet in the pages of no author, European or Asiatic, from the earliest ages to the close of the thirteenth century, is there the remotest allusion to cinnamon as an indigenous production, or even as an article of commerce, in Ceylon. I may add, that I have been equally unsuccessful in finding any allusions to it in any Chinese work of ancient date.”[280] This is, in fact, but another, though a striking instance, of the secrecy with which the ancients conducted the more valuable portions of their trade, and fully confirms the notice of the cinnamon trade of Herodotus, who could only have obtained his information about it from the merchants[281] or mariners who traded along the shores of Malabar or of Æthiopia to the south of Zanzibar. He speaks of it as so mysterious in its growth, and so difficult to obtain, that the most exorbitant prices were given for it in the markets of Europe; adding that, though in great demand in Tyre, Carthage, Miletus, and Alexandria, the merchants kept the secret of its _provenance_ as the Carthaginians kept that of British tin. [Sidenote: Change in the course of trade.] [Sidenote: Persian trade with India.]