Cinchona ledgeriana" had a yield of 8 to 13 percent quinine in bark grown in Dutch Indonesia which effectively out-competed the British Indian production. It was only later that the English saw the value and sought to obtain the seeds of "C. ledgeriana" from the Dutch. During World War II, the Japanese conquered Java and the United States lost access to the cinchona plantations that supplied war-critical quinine medication. Botanical expeditions – called Cinchona Missions – were launched in 1942-1944 to explore promising areas of South America in an effort to locate cinchona species that contained quinine and could be harvested
Jesuit's bark in the Jesuit College at Rome, who undoubtedly deserves the greatest credit after de Lugo for distributing the genuine unadulterated article, and to whom are attributed the Roman directions for its use "Schedula Romana", the earliest dating at least from 1651. In his friend Honoré Fabri, a French Jesuit, who stayed for a time in Rome, de Lugo won a determined defender of the bark against the first anticinchona pamphlet written by the Brussels doctor Jean-Jacques Chifflet. Under the pseudonym of Antimus Conygius, Fabri wrote in 1655 the first paper on cinchona published in Italy, as well as the first