Early the next morning, we went to visit the cave, of the entrance to which two views were sketched by Mr. Seymour. It is a perpendicular fissure, extending about one hundred and sixty feet into the horizontal limestone cliffs, which here form the north bank of the river. At times of high water, the Ohio flows in, and fills the cave nearly to its roof. In this cave, it is said, great numbers of large bones were some time ago found, but we saw no remains of any thing of this kind. Impressions and casts of the shells of submarine animals are seen in the rocks, forming the sides of the cave, as in all the strata of compact limestone, in this region. The organic remains here, do not appear to be so numerous as those of the rocks at the falls, and at Cincinnati; and are much less distinct, and visible in the fracture; indeed the fracture generally exhibits to the eye no vestige of organic remains. It is upon the surface only, and more especially in such parts of it as are in a certain stage of decomposition, that they are at all to be distinguished. As far as we could discover, they consist chiefly of the caryophyllæ, similar to the radiated species, so common at the falls of Ohio; of the encrinus, but of this our specimens were not so perfect as to enable us to determine the analogy. Numerous other remains were exhibited, but not sufficiently characterized to be referred to their proper places in the system. The top of the cliff, into which this fissure opens, is said to be the favourite haunt of great numbers of birds of prey. This is not improbable, as many hawks and birds of prey always choose high and inaccessible cliffs to build their nests in. We saw about the tops of these rocks, only one pair of hawks, which we took to be of the red-shouldered species, (falco lineatus,) but a heavy rain, which commenced soon after we had ascended, prevented {33} us from procuring a specimen. About the cave, we found some fragments of pottery, arrow points, and other articles of Indian manufacture. Near Shawaneetown are extensive salt manufactories, at a place heretofore called United States' Saline, affording employment and a source of trade to a part of the inhabitants of that village. Common salt, with the nitrates of lime, potash, &c. occur in great plenty, in connexion with the horizontal limestones and sandstones on the Ohio. Of these we subjoin some account, from the mineralogical report of Mr. Jessup.[048] On the 29th of May we passed the mouths of the Cumberland and Tennessee, the two largest rivers, tributary to the Ohio. At the mouth of the Cumberland is a little village called Smithland; where, for a considerable part of the year, such goods are deposited as are designed for Nashville and other places on the Cumberland.