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
Alexander von Humboldt a center of learning in the U.S., Humboldt met with some of the major scientific figures of the era, including chemist and anatomist Caspar Wistar, who pushed for compulsory smallpox vaccination, and botanist Benjamin Smith Barton, as well as physician Benjamin Rush, a signer of the Declaration of Independence, who wished to hear about cinchona bark from a South American tree, which cured fevers. Humboldt later published a treatise in English on cinchona. After arriving in Washington D.C, Humboldt held numerous intense discussions with Jefferson on both scientific matters and also his year-long stay in New Spain. Jefferson had only