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
Tree converted into bark and the cambium layer creates new phloem and xylem cells. The bark is inelastic. Eventually the growth of a tree slows down and stops and it gets no taller. If damage occurs the tree may in time become hollow. Leaves are structures specialised for photosynthesis and are arranged on the tree in such a way as to maximise their exposure to light without shading each other. They are an important investment by the tree and may be thorny or contain phytoliths, lignins, tannins or poisons to discourage herbivory. Trees have evolved leaves in a wide range of