A discourse on some of the principal desiderata in natural history, and on the best means of promoting the study of this science, in the United-States. [electronic resource] : Read before the Philadelphia Linnean Society, on the tenth of June, 1807. / By Benjamin Smith Barton, M.D., president of the Society; one of the vice-presidents of the American Philosophical Society; and professor of materia medica, natural history and botany, in the University of Pennsylvania