Rio Negro, an Amazonian tributary. Beginning as the Rio Guainía in southeastern Colombia, the Rio Negro meanders in an east-wardly direction for 1,400 miles. It serves as the natural boundary between Colombia and Venezuela before entering the Brazilian state of Amazonas. A mulch of tannin-bearing leaves, which drop and cover the rain-forest floor, discolors the Negro. The blue-black water of the Rio Negro flows into the light brown waters of the Solimões at the Encôntro das Aguas (meeting of the waters) 11 miles below Manaus. The two rivers flow side by side for about 4 miles before their waters finally merge.
Francisco de Orellana named the Negro when he first reached it on 3 June 1451. In 1657 Jesuits inhabited the river banks, where they found Manau, Aruák, and Tarumá Indians. In 1669, the Portuguese established a small outpost, Fort São José do Rio Negro, at the mouth of the Negro. After 1700, slaving along the river was common until many Indians succumbed to European diseases and forced labor. At the end of the eighteenth century, explorers Alexandre Rodrigues Ferreira and Baron Alexander von Humboldt traveled along the river. Richard Spruce spent from 1864 to 1870 wandering up the Negro, and he saw rubber being gathered the entire length of the river. Seringueiros still collect rubber and other rain-forest products, such as Brazilnuts from the banks of the Negro, but poor soils prevent it from supporting a dense population.
See alsoBrazil, Geographyxml .
Henry Bates, The Naturalist on the River Amazon (1863).
Alex Shoumatoff, The Rivers Amazon (1986).
Leslie Bethell, ed., Colonial Brazil (1987).
Little, Paul E. Amazonia: Territorial Struggles on Perennial Frontiers. Baltimore: Johns Hopkins University Press, 2001.
Smith, Anthony. Explorers of the Amazon. London: Viking, 1990.