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 "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