The sand of this river, which in the aggregate, has a very white appearance, consists principally of minute grains of transparent quartz, mixed with some which are red, yellow, and variously coloured. The shore, opposite the Loup village, is covered with shrubs and other plants, growing among the loose sands. One of the most common is a large flowering rose, rising to about three feet high, and diffusing a most grateful fragrance. The Symphoria _glomerata_, common in all the country west of the Mississippi thus far, is also a beautiful shrub very frequent at this place; the flowers are white, with a faint and delicate tinge of red, having the inside of the corolla densely villous, like the Mitchilla, to which plant it is manifestly allied. On the hills, at {138} a little distance from the river, we observed the _Cactus fragilis_. This plant, which was first detected on the Missouri by Lewis and Clark, has been accurately described by Mr. Nuttall. The articulations or joints of which it consists, are small, oblong, and tapering, but separate from each other with great readiness, and adhere by means of the barbed spines, with which they are thickly set, to whatever they may happen to touch. This has led to a saying among the hunters, that the plant grows without roots. In the afternoon a young Indian belonging to the Arikara nation on the Missouri, but who resided among the Pawnees, stopped at our camp, on his return from a solitary excursion to the Arkansa. He had brought with him, from one of the upper branches of that river, two masses of salt, each weighing about thirty pounds. This salt is pure and perfect, consisting of large crystalline grains, so concreted together as to form a mass about twenty inches in diameter and six in thickness. It had evidently been formed by the evaporation of water in some pond or basin, and that surface of the mass, which was its lower in its original position, was intermixed with red sand, indicating the sort of soil in which it is found. Mr. Peale procured some specimens in exchange for tobacco. This Indian had been many days absent, on his excursion, and as he sat upon his horse before our encampment we had an opportunity to note a trait in the Indian character, which has been the subject of remark by many authors, and which we had previously observed in several instances ourselves; we allude to the apparent coolness which friends, and the nearest relatives, observe to each other when they meet after a long separation. Several of his fellow townsmen, who were about our encampment, hardly noticed him when he first appeared, and it was only after the lapse of a considerable interval {139} that one of them spoke to him, but without any visible ceremony of greeting.