But the india-rubber and the cacao are not the only treasures worth collecting in these forests. Even now the export of the Para nuts, the fruit of the _Bertholletia excelsa_, yields an annual revenue of two hundred thousand dollars; and the copaiba oil and the urucu, the seeds of the _Bixa orellana_, used for dyeing, about one hundred thousand dollars. These sums seem small enough, it is true, but there are perhaps a hundred times those values of the rich-flavored nuts rotting unheeded in the forests, and above a score of other rich oily seeds, at present collected only for the use of the natives, not to mention several resins which yield the finest varnishes, plants giving the most brilliant hues, and others with fibres that would serve not only for the finest weavings, but also for the strongest ropes; besides about forty of the most indispensable drugs, all which might become most valuable articles of export.... Notwithstanding the fertility of tropical vegetation, I doubt whether any other part of the world, in the same latitude, can offer as great a number of useful plants as does the Amazon Valley; and now, when all-transforming steam is about to open up to us this rich emporium, European industry should take advantage of the hitherto neglected treasures. What might not be done with the fibres, some of which surpass our hemp and flax in all respects? The curaua, for example, a sort of wild pine-apple, gives a delicate transparent flax of a silky lustre, such as is used in the Philippine Islands, on a large scale, it appears. It is sold under the name of _palha_ at Rio de Janeiro. The tucum and the javary would make excellent ropes, cords, nets, etc., well calculated to resist moisture and rot; and the piassaba, the murity, etc., would readily supply solid brushes, brooms, hammocks, hats, baskets, mats; while the snow-white bast of others would give excellent paper. The lianas or cipos of these countries are, besides their minor uses, quite indispensable to the half-civilized natives for the construction of their light cottages, taking the place (as they do) of our nails and cramp-irons, beams, posts, and rafters. The whole palm-leaf roof is fastened, and artificially interwoven and intertwined, with tough creepers of nearly an inch thickness.... In the hot lowlands of the Amazon, in the shade of endless forest, there is many an herb of mysterious virtue, as yet known only to wild Indian tribes, while the fame of others has already spread over the ocean. Who has not heard of the _urary_, or _curare_, the quick arrow-poison which, in the hands of clever physiologists and physicians, promises not only to become a valuable drug, but to give us interesting disclosures on the activity of the nerves?