Quinine the Quechua, who are indigenous to Peru, Bolivia and Ecuador, to halt shivering due to low temperatures. The Quechuas would mix the ground bark of cinchona trees with sweetened water to offset the bark's bitter taste, thus producing tonic water. The Jesuits were the first to bring cinchona to Europe. The Spanish were aware of the medicinal properties of cinchona bark by the 1570s or earlier: Nicolás Monardes (1571) and Juan Fragoso (1572) both described a tree that was subsequently identified as the cinchona tree and whose bark was used to produce a drink to treat diarrhea. Quinine has been
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