Note 85 — OBSERVATIONS ON THE MINERALOGY AND GEOLOGY OF A PART OF THE UNITED STATES WEST OF THE MISSISSIPPI.

"A very extensive bed of native argil occurs on the right bank of the Mississippi, commencing near the head of Tiawapeti Bottom, at the Little Chain, about forty miles above the junction of the Ohio and Mississippi, and extending with very little interruption near six miles above the Grand Tower, a distance of thirty-four miles. Beyond these limits I have not observed it. Its colour is snow-white; structure fine, pulverulent; fracture dull earthy. It is amorphous, and adheres to the tongue. It does not effervesce with acids, even in the slightest degree. The bed of argil reposes on horizontal strata of siliceous sandstone, and is overlaid by shell limestone. In the vein of argil, nodules and veins of flint are arranged so as to make with the horizon an angle of about fifty degrees. The argil has been taken to New Orleans, Pittsburgh, St. Louis, &c. in considerable quantities, supposing it to be chalk, for which substance it has been used." Mr. Jessup's MS. Report.

"Flint.—This occurs in nodules and veins in a bed of native argil, above Tiawapeti Bottom. Its colours are bluish-gray and greenish-black. It gives fire with steel; fracture is conchoidal, and the edges are translucent. The veins of flint dip to the south-east." Ibid.

Imbedded in the chalk of Cape Girardeau, are occasionally found nodules of flint, which are enveloped by a hard crust of calcareous carbonate, arranged in concentric layers. Its colour is grayish-black, breaks with a perfectly conchoidal fracture, is translucent on the edges, and readily gives fire with the steel. Schoolcraft's View of the Lead Mines, p. 180.—James.