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.
Bark painting from Stringybark ("Eucalyptus tetradonta"). The bark must be free of knots and other blemishes. It is best cut from the tree in the wet season when the sap is rising. Two horizontal slices and a single vertical slice are made into the tree, and the bark is carefully peeled off with the aid of a sharpened tool. Only the inner smooth bark is kept and placed in a fire. After heating in the fire, the bark is flattened under foot and weighted with stones or logs to dry flat. Once dry, it is ready to paint upon. Earth pigments—or ochres—in