The bark of the tree, a genus with about 25 species from the family of Rubiaceae (madder and coffee are another two plants from that group) contains quinine. Amerindians in Peru knew of its anti-malarial activity and used it for the resulting fevers. They passed on this knowledge, around 1630, to their European conquerors. Back in Europe, this cure became known as “The Jesuits’ Bark,” which did not endear it to the public in Protestant or Anglican countries. Moreover, such a treatment was not consonant with the still dominant Aristotelian theory of bodily humours and with Galenic medicine.
Well-meaning Jesuits must have decided that helping mankind cope with the scourge of malaria was well worth diassociating themselves from this medication. They came up with a fairy tale, which attributed to it miraculous recoveries from the periodic fevers, either undergone or performed by the Countess of Chinchón. This apocryphal story, spread during the latter part of the seventeenth century, succeeded in the progressive adoption of quinine by physicians. It has left its trace in the genus name for these quinine-producing trees.
Quinine works by attacking the Plasmodium falciparum parasite, inoculated by the female of the Anopheles mosquito, which is the vector of malaria, a disease which continues to affect about half-a-billion people and to kill about two million worldwide every year. One of the technologies currently tested against malaria is sterilization of male mosquitoes, who are then released into the wild.
My book, in French, Copal benjoin colophane … , Le Pommier, Paris, 2007, provides more information on cinchona.