4. _Granular Limestone_ is abundant at the _Cave_ or _Falls_, in Adams, and on both sides of the Hoosack. The _Cave_ or _Falls_, (O) is a singular chasm between limestone rocks. A small stream, which appears once to have run on the surface of the hollow between two small elevations, has now worn a passage many feet in depth through the limestone. The chasm is narrow, winding in its course several rods long, and its opposite sides were connected, till four years ago, by a natural bridge of limestone. From the bridge to the water is 70 feet. There is a dark cavern of several feet diameter, and some passages into the rocks. The white marble walls, the foaming of the water below, the piles and irregularity of the rocks, and the thick overhanging trees, make the scene very wild and interesting. The limestone rests on mica slate. On the west bank of the Hoosack, and east base of the hill, (L) the same coarse-grained and white limestone is found, resting on the mica slate at the west of it. At the north and west base of Saddle Mountain, (E) and at a less elevation than the quartz, are extensive strata of limestone, inclining the same way as the mica slate of the mountain. It is less distinctly granular, and less white than the other, but belongs to the same rock. It forms tolerably good marble. Between the strata are crystals of carbonate of lime, rhomboidal, and tending to the _lenticular_ form. Some of these strata appear to be composed of blended crystals of this kind. In one place are strata of several rods in length and breadth, which are inclined to the southwest, and thus lie against the mica slate of the mountain. The inclination is about forty-five degrees. Unless this limestone be connected with that on the east of Saddle Mountain, (and no connexion has yet been traced,) it must be considered as lying on both sides of the mica slate, or alternating with it. 5. _Argillaceous Slate_ rests on quartz on Stone Hill, and is also found low down in the valley connected with limestone. It constitutes the hill (P) connected with the Taconick range, and also Northwest hill, (Q) whose base is compact limestone. A few miles north, this slate is distinctly marked, and in about 12 miles, forms hills of _roof slate_ in Hosack, New-York. It is annually carried in large quantities to Albany. On the first-mentioned hill, it contains some _talc_. 6. _Aluminous slate._ This is found in argillaceous slate, in Pownal, 5 miles north, at the base of a hill east of the Hoosack. It is used to _set_ colours. 7. _Chlorite._ In rounded masses, generally with quartz, scattered through the valley in Williamstown, and found at an elevation of some hundred feet on the hills of the Taconick range. Chlorite slate has already been mentioned as occurring on the same range. 8. _Rubble Stone._ In rounded masses through the valley.