In some respects the Russian "caravan route" is the most important channel of the tea-trade. The tea is collected mainly at Tientsin, and sent by camel caravans through Manchuria to the most convenient point on the Siberian railway. Not only the shipments of brick tea[36] for the Russian market, but the choicest products for western Europe also are sent by this route. It is probably an economical way of shipping the brick tea, but a more expensive method of shipment for the latter could not be found easily; it is preferred from the fact that, no matter how carefully sealed, the flavor of tea is materially injured by an ocean voyage. It is evident, therefore, that for the tea product alone the Siberian railway will soon become an important factor in the commerce of Europe. Shipments of tea are also sent from Canton to Odessa, Russia, but this route is not less expensive in the long run than the Cape route, and the tea suffers as much deterioration from the shorter as from the longer voyage. =Cacao.=--Cacao, the "cocoa" of commerce, consists of the prepared seeds of several species of _Theobroma_, the greater part being obtained from the _Theobroma cacao_. The name is unfortunately confused with that of the cocoa-palm, but there is no relation whatever between the two. The seeds of the cacao were used in ancient America long before its discovery by Columbus, and the latter carried the first knowledge of it to Europe. By the middle of the seventeenth century it was much used in Spain, and less than a hundred years later it had become the fashionable drink of western Europe. The cacao-tree, originally native to Mexico, is now cultivated throughout tropical America and the West Indies. It is not cultivated to any extent in the Eastern continent. The fruit consists of large, fleshy pods, which are cut from the trees usually in June and December. The seeds are then piled in heaps, or else packed in pits, and allowed to undergo a rapid fermentation for a period of several days, to which process their flavor is mainly due. The roasted and broken seeds are the cocoa-nibs of commerce. The husks are known as cocoa-shells. A very large part of the cacao product comes from Ecuador, Guayaquil being perhaps the chief market of the world. The Venezuelan and Brazilian products, however, are the choicest; these are known in commerce respectively as Caracas and Trinidad cacao. Spain, Portugal, and France are the chief purchasers, and in the first-named country the consumption per person is five or six times as great as in other countries.