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
Jesuit's bark came to Spain in 1643 while procurator of the Peruvian province of his order, proceeded through France (there is an alleged cure of the young Louis XIV, when still dauphin, effected by Father Tafur by means of Peruvian bark), and thence to Italy as far as Rome. The celebrated Jesuit theologian John de Lugo, who became a cardinal in 1643, learned about the cinchona from Tafur, and remained from 1643 until his death in 1660 its faithful advocate, zealous defender, and generous, disinterested dispenser in Italy and the rest of Europe, for which he was honoured in the appellation of