Edward Stone (natural philosopher) piece of bark from a willow tree and was struck by its extremely bitter taste. Knowing that the bark of the Peruvian cinchona tree − from which quinine (used in the treatment of malarial fevers) is derived − has a similarly bitter taste, he surmised that the willow might also have therapeutic properties. Stone's interest in willows was due to the ancient "doctrine of signatures" – whereby the cause of a disease offers a clue to its treatment. According to Stone: "As this tree delights in a moist or wet soil, where agues chiefly abound, the general maxim that many
Hugh Algernon Weddell des environs de Paris (1845). In 1843, he was invited to join the expedition of François Louis de la Porte, comte de Castelnau to South America, and he explored and collected botanical specimens on that continent for five years. In May 1845, Weddell left the expedition which was then in Paraguay, and proceeded on a solitary journey which would take him into Peru and Bolivia. Before leaving Paris, he had been particularly instructed by the Muséum national d'Histoire naturelle to undertake a thorough investigation of the "Cinchona" plant, or "fever bark" tree in its native habitat. "Cinchona", the source of