Malaria saved the lives of thousands of workers and helped develop the methods used in future public-health campaigns against the disease. The first effective treatment for malaria came from the bark of cinchona tree, which contains quinine. This tree grows on the slopes of the Andes, mainly in Peru. The indigenous peoples of Peru made a tincture of cinchona to control fever. Its effectiveness against malaria was found and the Jesuits introduced the treatment to Europe around 1640; by 1677, it was included in the London Pharmacopoeia as an antimalarial treatment. It was not until 1820 that the active ingredient, quinine,
Cinchona "plea for the correct spelling of the genus "Chinchona"". A Spanish physician, Juan Fragoso wrote of bark powder from an unknown tree in 1600 that was used for treating various ills. Nicolas Monardes also wrote of a New World bark powder used in Spain in 1574. Both identify the sources as trees that do not bear fruit and having heart-shaped leaves and it has been suggested that these references could be to "Cinchona" species. The name Quina-Quina or Quinquina was suggested as an old name for Cinchona used in Europe and based on the native name used by the Quechua