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
Schedula Romana treatment for malaria was found in the forests of the Andes in Peru. A such called fever tree, whose bark, made into powder and given as a beverage, cured the fevers and was known to have produced miraculous results in the local population. The bark was obtained from several species of the genus "Cinchona", of the Rubiaceae family. Popularized in Europe through the work of jesuits in America, the cinchona tree bark came to be known as Jesuit's bark. Perhaps the most prominent popularizer of the Jesuit's bark was a Spanish Jesuit Cardinal, Juan de Lugo. In 1643, Cardinal Lugo