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
Cinchona viceroy in Lima. While the veracity of the claims and the details are highly debated leaving it best treated as a legend, the curative properties were known even earlier. The history of the plant, their extracts, and the cures are however highly confused and controversial. Suggestions that the plant went by the native name of Quina Quina which yielded Quina bark have been questioned. Other fever cures from South America were known as Jesuit's Bark and Jesuit's Powder in Europe earlier but although they have been traced to "Cinchona", there is evidence of materials being derived from other species such