It is to the persevering energy and great talent of that distinguished French botanist Dr. Weddell that we owe our knowledge of the chinchona regions of Bolivia and Southern Peru, and especially of the inestimable quinine-yielding species which he identified as the _C. Calisaya_. Dr. Weddell accompanied the scientific expedition of the Count de Castelnau, which was sent out by Louis Philippe to South America, and, after crossing the vast empire of Brazil, entered Bolivia by the country of the Chiquitos in August, 1845. It was Dr. Weddell's chief object to examine the chinchona region of this country, and his first step was to proceed to Tarija, to ascertain the extreme southern limit of the chinchona-trees, which he discovered in 19° S. lat. He named the species _C. Australis_. Dr. Weddell then commenced a thorough exploration of the Bolivian chinchona forests, making his way over the most difficult country, from Cochabamba, through Ayopaya, Enquisivi, and the _yungus_[80] of La Paz; where the species of chinchonæ continued to multiply under his eye. In Enquisivi he first met with and studied the _C. Calisaya_, which he named and described, collecting much information respecting the trade, and the methods of collecting bark. In 1847 he entered the province of Capaulican, descending the river Tipuani, where he was attacked by fever, and ascending the Mapiri. At Apollobamba, the centre of the most ancient bark-collecting district, he found that the surrounding forests were quite cleared of chinchona-trees, and that it was necessary to seek for them at a distance of ten or twelve days' journey from any inhabited place. In June 1847 Dr. Weddell entered the Peruvian province of Caravaya, examined the chinchona forests of the valleys of Sandia (San Juan del Oro) and Tambopata, and concluded his investigations by a visit to the lovely ravine of Santa Anna, near Cuzco. Dr. Weddell was accompanied in his visit to the valleys of Santa Anna by M. Delondre, a manufacturer of quinine at Havre, who, after contemplating the project of paying a personal visit to the chinchona forests for twenty years, had at length set out, landed at Islay in July, 1847, and proceeded by way of Arequipa to Cuzco. M. Delondre appears to have employed a contractor to supply him with bark, who failed in his engagements, and of whom the French quinine manufacturer bitterly complains as a second Dousterswivel.[81] MM. Weddell and Delondre finally left the chinchona forests in September, 1847, and set out for the coast of Peru. Dr. Weddell's valuable monograph on the chinchona genus, '_Histoire naturelle des Quinquinas_,' the most important work that has yet appeared on the subject, was published at Paris in 1849.