For a description of the cavern from which these specimens came, we refer to the succeeding memoir, by Mr. Kain. ART. X. _Remarks on the Mineralogy and Geology of the Northwestern part of the State of Virginia, and the Eastern part of the State of Tennessee._ By Mr. JOHN H. KAIN, of Tennessee. The most prominent as well as the most beautiful feature of this country, is that succession of mountain and valley, ridge and vale, which we meet with in traversing its surface. The grand range of Alleghany mountains enters Virginia about the 39th degree of north latitude; and, pursuing a southwestern course, spreads out upon the east end of Tennessee, and terminates near the southern boundary line of that state, in the Alabama territory; and about the 34th parallel of north latitude. In this view are included the Blue Mountains, the North Mountains, the Allegheny, (properly so called) the Cumberland, Clinch, Iron, and Smoky mountains, together with a variety of smaller mountains, spurs, and ridges, all running parallel to each other, from the northeast to the southwest; and all, I believe I may say, covered with forests, and presenting to the eye of the naturalist a most interesting field for speculation and improvement. With a few exceptions, the geologist meets with none of those remarkable appearances which indicate the changes and convulsions which have been wrought by time, the great enemy of nature. Occasionally we are presented with a view of a sublime precipice, formed by a section which a river appears to have made for itself through an opposing mountain; and the large masses of ruins, which lie scattered around such a place, seem, to the imagination of the solitary traveller, the historical records of commotions, awful even in retrospect. Most commonly, however, the mountains seem to have lain for ages in undisturbed repose; and the streams of water, when they have crossed them, have sought an easy passage through the ravines, which do not so often divide a mountain, or ridge, at right angles, as wind between the ends of two opposing spurs, which pass each other, gradually declining into the champaign country at their mutual base. Through this whole extent of country we rarely meet with any remarkable falls of water; the obvious reason of which is, that the rocks are so soft that they are easily worn down to the level of the beds of rivers. But shoals, or shallows, are frequent, and are formed by beds of rounded sandstone, spread out into a broad base, over which the water often rushes with no small violence and noise.