The Rio Negro or Cusu-debu rises at a great elevation, and separates the Pampas from Patagonia. In its long course through arid deserts to the Atlantic it does not receive a single adjunct, but it forms a communication between that ocean and Chile, as it reaches a pass in the Andes that is free from snow. There is some vegetation in its immediate neighbourhood; it has a bar at its mouth, and is navigable only for four miles above Carmen; it has floods twice in the year, one from the rains, the other from the melting of the snow in the Andes. Some other streams from the Chilian Andes run through, but do not fertilize, the desolate plains of Patagonia. There are various rivers in South America, unconnected with those described, which in any other country would be esteemed of a high order. Of many which descend from the mountains of Guiana, the Essequibo is the largest; its general width is a mile and a quarter; its water, though black, is transparent; and on its banks and those of all its adjuncts the forest reigns in impenetrable thickness. It rises in the Sierra Acaray, which separates its basin from that of the Amazons, and, after a northerly course, falls into the Atlantic near 7° N. lat. by an outlet 14 miles broad, separated by three low islands into four branches. Sir Robert Schomburgk, whose scientific journeys have made us acquainted with a country of which so little was known, has shown that, by cutting a canal three miles long between the Madeira and Guapore, an affluent of the Mamore, an inland navigation might be opened from Demerara to Buenos Ayres, over an extent of 42 degrees of latitude, with the exception of a portage of only 800 yards in the rainy season between Lake Amucu and the Quatata, a branch of the Rupununi, which flows into the Essequibo. But that is not the only water communication between Guayana and remote countries, great though the distance be, for the Napo, a tributary of the Solimoes, offers communication with Quito, the Huallaga with Peru and countries not far distant from the Pacific Ocean. By the Rio Negro, the Orinoco, the Cassiquiare, and its tributary the Meta, there is uninterrupted navigation to New Granada and to within eight miles of Santa Fé de Bogota. “If,” says the distinguished traveller already mentioned, “British Guayana did not possess the fertility which is such a distinguishing feature, this water communication alone would render it of vast importance; but, blessed as it is with abundant fruitfulness, this extensive inland navigation heightens its value as a British colony; and, if emigration sufficient to make its resources available were properly directed thither, the port of Demerara would rival any in the vast continent of South America.” It is certainly very remarkable that the tide of emigration has never set towards a country of such promise, abounding in valuable natural productions, and so much nearer to Great Britain than her colonies in the Pacific.