[106] Charles Nicholas Sigisbert Sonnini de Manoncourt was a French naturalist and traveller, who visited Egypt, Greece, and Asia Minor during the years 1777-80. He lost his fortune by the Revolution, and spent the remainder of his life in writing and editing scientific works. The book here referred to is _Voyage dans la haute et dans le basse Egypt_ (Paris, 3 vols., 1799). It was twice translated into English.—ED. The hills on the south side of the Platte, above the confluence of the north fork, become more abrupt and elevated, approaching in character those of the Missouri which are destitute of stone. There is here the same transcript of Alpine scenery, in miniature, which constitutes so striking a feature in the Missouri landscape, when viewed from the river bottom. We had no sooner crossed the Platte, than our attention was arrested by the beautiful white primrose (œnothera pinnatifida, N.) with its long and slender corolla reclining upon the grass. The flower, which is near two inches long, constitutes about one-half of the entire length of the plant.[107] [107] Considerable additions were made, about the forks of the Platte, to our collections of plants. We found here, among others, the Pentstemon cristatum, N. Coronopus dydima, Ph. Evolvulus Nuttallianus, Roemer, and Shultz. Orobus dispar, Cleome tryphilla, Petalostemon candidum, Ph., and P. violaceum. Aristida pallens, N. two species of a genus approximating to Hoitzia, several species of Astragalus, and many others.—JAMES. The valley of the Platte, above the forks, is much narrower, and a little more irregular in direction than below, and is frequently interrupted by small hills running in towards the river. On ascending these hills, we found them of a coarse sand, and containing more gravel and small pebbles than below. Among the gravel stones, small fragments of flesh-coloured {155} felspar are distinguished. About the summits of the hills we saw some detached pieces of fine carnelion, with agates and calcedony. We had often examined, with some anxiety, the turbid waters of the Platte, hoping thereby to gain information respecting the predominating rock formations of the mountainous district, from which that river descends. It had been a received opinion among some of the geologists of the United States, that the Rocky Mountains were not of primitive rocks; we had hitherto observed nothing which could either confirm or invalidate this opinion.