per lb was given for specially prepared " plantation Para."
A similar depression is presented by methyl alcohol (67°) and methyl ether (-23 °) Among the aromatic di-substitution derivatives the ortho compounds have the highest boiling-point, and the meta boil at a higher, or about the same temperature as the para compounds.
The region, which abounds in valuable rubber forests, was settled by Bolivians between 1870 and 1878, but was invaded by Brazilian rubber collectors during the next decade and became tributary to the rubber markets of Manaos and Para.
Partly for this reason and partly because pieces of wood and dirt are apt to be included with the scrap, the market value of Ceara rubber is usually less than that of Para.
America which furnish rubber of secondary commercial importance are Hancornia speciosa, yielding the Mangabeira rubber of Brazil, and species of Sapium furnishing the Colombian rubber and much of the rubber of Guiana (derived from Sapium Jenmani), which is scarcely inferior to the rubber of Para.