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 a strong decoction of the cinchona bark served with wine. Wine was used because some alkaloids of the cinchona bark are not soluble in water, but are soluble in the ethanol in wine. In 1681 "Água de Inglaterra" was introduced into Portugal from England by Dr. Fernando Mendes who, similarly, “received a handsome gift from (King Pedro) on condition that he should reveal to him the secret of its composition and withhold it from the public”. In 1738, "Sur l'arbre du quinquina", a paper written by Charles Marie de La Condamine, lead member of the expedition, along with Pierre Godin