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 "Pulvis Patrum". The history of cinchona bark, which dates back more than 300 years, has greatly influenced that of pharmacy, botany, medicine, trade, theoretical and practical chemistry, and tropical agriculture. Circa 1650, the physician Sebastiano Bado declared that this bark had proved more precious to mankind than all the gold and silver that the Spaniards had obtained from South America, and the world confirmed his opinion. See also Swords, Ships and Sugar - The History of Nevis, by Vincent K. Hubbard, p. 73, where a large amount of "Peruvian Bark" had been captured by the pirate Basil Ringrose, also known