COMMUNICATIONS. Page. Chilton's defcription and analysis of Heavy Spar from New Jersey Gibb's Mineralogical notice respecting the Weft River Mountain, Connecticut Grifcom's chemical examination of a mineral water from Litchfield, State of Wifter's defcription of Melanite from Pennsylvania, and Amber from New Bruce's mineralogical notice refpecting American Fluates of Lime Silliman's defcription of the Lead Mines near Northampton, Maffachusetts Mitchill's Physical Geography of Mountains, in New Jersey Meade's mineralogical notice refpecting elaftic Marble, from Maffachusetts 93 Mitchill's account of the remains of marine animals in a foffil state, in New Meade's defcription of feveral newly difcovered ores of lead from Northampton 149 Arnell's account of the Cheechunk Spring at Goshen, Orange County Inquiry into the chemical characters and properties of Rhode Island coal, with its application to arts and manufactures Cloud's experiments on Palladium found in combination with Gold Brown's description of a Nitre Cave, on Crooked Creek, Kentucky Williams on the Indications and methods of fearching for coal Smithson on the compofition of Zeolite Hayden's Geological Sketch of Baltimore Latrobe on the Sand hills of Cape Henry in Virginia Jameson on the Topaz of Scotland 100 113 166 182 243 THE AMERICAN MINERALOGICAL JOURNAL. JANUARY, 1810. I. Descriptive Catalogue accompanying a suite of Mineral specimens presented to the Editor by his colleague, S. L. MITCHILL, M. D. Professor of Natural History and Botany, in the University of the State of New-York. THESE pieces were collected during a tour made, in the summer of 1809, to Niagara. They may serve to illustrate the mineralogy as well as the geology of that region, and of some places along the Mohawk river. 1. Brittle slate, or fragile shistus, which forms the inferior strata at the great cataract. The layers of this are full of cracks and flaws; and at the denuded edge, the fragments may be picked out by the fingers. They constitute part of the ruinous mass at the foot of the precipice below, through which the visitor to the falls must travel. This shistus decaying and crumbling, undermines the superior strata of the lime-stone, causing them to tumble down and enlarge the chasm into which the river pours. 2. Calcareous carbonate, or lime-stone, which forms the upper layers of rocks at the falls. It overlays the shistus VOL. I. A. (No. 1,) and is supported by it. It is of the species called swine-stone, or lapis suillis, as appears from the strong and unpleasant odour it emits when rubbed or broken. In the neighbourhood the inhabitants burn it to quick-lime. It affords a good cement, and generally makes very white walls. Its disposition is tabular, and its strata extensive and horizontal. Their termination is abrupt and steep. Over and down these precipices, the water descends at the rapids, and finally plunges at the grand cataract. 3. A fine specimen of the calcareous rock, which predominates at Niagara, covered on one side by rhomboidal crystals. They are of a clear white; and are probably carbonates, as they emit bubbles when exposed to the action of a stronger acid. Their angles are all oblique. 4. Another sample of rhomboidal crystallizations. But on this, as well as on the preceding No. 3, there is an appearance of semi-transparent crystals, which manifest a greater tendency to assume the rectangular figure, and to form cubes. These might at first glimpse be taken for fluates of lime. In confirmation of your opinion that they contained no fluoric acid, I can now assure you that I made repeated experiments on some of the fairest of these crystals, assisted by Mr. Griscom, without finding any thing that would corrode glass. Though we pulverized this peculiar substance in a mortar of porphyry, and carefully added sulphuric acid in a proper temperature, we could not satisfy ourselves that the smallest erosion was produced on the surface of a window-pane duly prepared with wax. 5. Calcareous rock, carrying crystals resembling dogstooth spar. 6. A piece of the calcareous rock charged with iron pyrites. This piece is very valuable, as it contains that link in the chain of evidence which demonstrates the conversion of common lime-stone to gypsum hereabout; or in other words, the change of the calcareous carbonate to a sulphate. |