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 of the long list of brochures defending its use and the only independent article on this bark which has been issued by a Jesuit. The two Genoese, Girolamo Bardi, a priest, and Sebastiano Baldo, a physician, who were among the pioneer advocates of the plant, were intimate with the cardinal, and Baldo prefixed to his principal work a letter from de Lugo, dated 1659, on cinchona, which shows that the cardinal even when seventy-seven years old was still active in its behalf. Circumstances created a suitable opportunity for disseminating the bark from Rome throughout Europe by means of the Jesuits.