Thus gentlemen have I endeavoured to point out some of the more prominent of the numerous exertions made by your late president, in the cause of American science. The advantages that have resulted to its interests, by such substantial coun-
finite obligations."—In justice to Mr. Pursh I beg leave to state, that for the assistance so received, he gives Mr. Nuttall all due credit, although there appears to be some little disagreement between them, respecting the discovery of a new genus of plants, called Bartonia by their joint consent, in honour of, to use Mr. Pursh's words, "their mutual friend, Dr. B. S. Barton." Respecting Mr. Nuttall, I beg leave to quote from a manuscript paper now in my possession, written by Dr. Barton three or four days before his death, the following observations:
"I became acquainted with this young Englishman in Philadelphia several years ago; and observing in him an ardent attachment to, and some knowledge of botany, I omitted no opportunity of fostering his zeal, and of endeavouring to extend his knowledge. He had constant access to my house, and the benefit of my botanical books.
"In 1810 I proposed to Mr. Nuttall the undertaking of an expedition, entirely at my own expense, and under my immediate direction, to explore the botany, &c. of the northern and the north-western parts of the United States, and the adjoining British territories. Accordingly, having provided him with a special passport from the president of the United States, Mr. Madison, and with whatever else I deemed necessary, together with a considerable collection of manuscript queries and memoranda, Mr. Nuttall took his departure from Philadelphia in April, 1810.
"His route was by Pittsburg to Detroit, Michilimakinak, Fox River, the Falls of St. Anthony, &c. He deviated, however, from the route which had been pointed out to him, having been prevailed upon to ascend the Missouri in company with some of his own countrymen, some Americans, and others, whose objects were principally traffick.
"He proceeded to the Mikanee-towns; from thence to the territory of the Mandan Indians, in the boat of a Spanish gentleman; and in the same vessel descended the Missouri to St. Louis, near the confluence of this great river with the Mississippi, in the autumn of 1811.
"Among a very considerable number of plants which he observed and collected, in the course of his journey, there were two species of a genus which he observes in his notes to have the "facies" or aspect of cactus, and which he very properly referred to the class and order of icosandria monogynia—he named this genus Bartonia. One of the species he calls Bartonia superba, and the other Bartonia polypetala. The former he found in flower in August and September; growing all the way from the river Platte to the Andes, on broken hills and the clefts of rocks—(Pursh adds, not I fear on the best authority, 'and on volcanick soil.') He speaks of it as a plant (herba) about three feet high, whose 'splen-
