By a kind of compensation, the Tropical Forests, which contain so many poisonous plants, produce also a great number of the highest utility to man. Some offer him efficient remedies against the diseases which beset his frame; others nourish him with the fecula of their roots or the delicious substance of their fruits; others again supply him with textile fibres, dyeing or resinous materials, and woods which the artist and the artisan convert to numerous uses. This vegetable wealth has been widely distributed over South America. It will suffice to indicate a few of its more notable sources. If we direct our attention to medicinal plants, we shall probably find none more precious than the Quinquina, whose bark is the most effective of all febrifuges, and which is endowed, moreover, with very valuable tonic and depuratory properties. Sir Samuel Baker, in his recent address to the British Association at Dundee, pronounced it the traveller's best friend, the powerful weapon with which he could securely enter the African wilderness, and successfully contend against its demon-host of fevers and agues. The Quinquinas (genus, _Cinchona_; family, _Rubiaceæ_) are trees or evergreen shrubs with large and handsome leaves, and flowers whose form and fragrance remind one of the lilac. They are diffused over the two slopes, but chiefly along the eastern slope, of the Andean Cordilleras, in the republics of Venezuela, New Granada, Ecuador, Peru, and Bolivia. The traveller meets them occasionally in picturesque groups or thickets which the Peruvians call _Manchas_ (spots); but they are more frequently scattered in immense forests. What of the lactiferous and resinous plants? South America is the native land of the trees whence we extract the resinous gums called "Animé d'Amérique," "White Amber," and "Soft Brazilian Copal," and the "Hevea Guyanensis," which furnishes the greater portion of the caoutchouc imported into Europe. Caoutchouc was described for the first time in 1736, by the scientific travellers Bouguer and La Condamine, members of a Commission despatched to Peru by the Parisian "Académie des Sciences," to measure an arc of the meridian. A few years later, the engineer Fresneau, who resided for a long time in Guiana, collected, with the assistance of a native, ample information in reference to caoutchouc and the tree which produced it. Finally, in 1768, was found in a work by the traveller Aublet on the Flora of Guiana, the description and figure of the _Hevea_. This tree attains a height of 50 to 70 feet. The almond enclosed in the kernels of its fruits is white, of a very agreeable taste, and much esteemed by the Indians, who also extract from it an oil for seasoning their food.