Cinchona in the year 1851. Mr. [Thaddäus] Haenke mentioned the existence of cinchona bark on his visit to Yuracares in 1796". (Source: Exploration of the Valley of the Amazon, by Lieut. Lardner Gibbon, USN. Vol.II, Ch.6, pp. 146-47.) The cultivation of cinchona led from the 1890s to a decline in the price of quinine but the quality and production of raw bark by the Dutch in Indonesia led them to dominate world markets. The producers of processed drugs in Europe (especially Germany) however bargained and caused fluctuations in prices which led to a Dutch-led Cinchona Agreement in 1913 that ensured a
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