Cinchona genus is the source of a variety of alkaloids, the most familiar of which is quinine, an antipyretic (antifever) agent especially useful in treating malaria. Cinchona alkaloids include: They find use in organic chemistry as organocatalysts in asymmetric synthesis. Alongside the alkaloids, many cinchona barks contain cinchotannic acid, a particular tannin, which by oxidation rapidly yields a dark-coloured phlobaphene called red cinchonic, cinchono-fulvic acid or cinchona red. In 1934, efforts to make malaria drugs cheap and effective for use across countries led to the development of a standard called "totaquina" proposed by the Malaria Commission of the League of Nations.
Birch bark the phloem, kills the tree by preventing the flow of sap to the roots. To prevent it from rolling up during storage, the bark should be spread open and kept pressed flat. Birch bark can be cut with a sharp knife, and worked like cardboard. For sharp bending, the fold should be scored (scratched) first with a blunt stylus. Fresh bark can be worked as is; bark that has dried up (before or after collection) should be softened by steaming, by soaking in warm water, or over a fire. Birch bark was a valuable construction material in any part of