Bottle containing quinine (guiaca), 19th century.

UNITED KINGDOM - JULY 30: Glass bottle with cork and wooden lid. Quinine is a white crystalline alkaloid with a bitter taste, which is almost insoluble in water and dissolves in alcohol and other organic solvents. Derived from cinchona bark, (named 'quina quina' by the indiginous people of Peru), which was brought to Europe from South America in the mid 17th century, quinine was isolated in 1820 by the French chemists Caventou and Pelletier. Quinine was the specific agent used to treat malaria, but was also used to allay general fever and pain. (Photo by SSPL/Getty Images)