and related compounds which have been used for a few centuries in the treatment of malaria but have now been supplanted by its alkaloids. The cinchona tree is native to South America. Since one of the primary symptoms of malaria is fever, it makes sense that the use of cinchona bark might be generalized to all fevers. They would have had to be cautious of toxic effects--nausea, vomiting, malaise & hearing loss. I'll try to see if cinchona is related to birch which my people (Native Americans) used as an agent for fever relief.