32 Putnam Hill Strata. 



dred grains of the nitrate, which would give to the coal about sixty 

 per cent of carbon ; it requiring about thirteen grains of wood coal, 

 to decompose that quantity of nitre. Forty grains of this coal heat- 

 ed to redness in a crucible, and kept at that point for a few min- 

 utes, left twenty one grains of coke, which contained but little earth, 

 for fourteen grains of this coke, deflagrated, one hundred grains of 

 nitre. While burning in a grate, it flames freely at first, but soon 

 melts and runs together, obstructing the circulation of the air through 

 the burning mass. This character is common to the coal from the 

 upper deposit, not only at several remote points in Ohio, but also 

 on the Kenawha river in Virginia. The bitumen it contains is very 

 pure and free from sulphur. — 3 feet. 



5. Slaty, micaceous sandstone, in thin layers, from half an inch 

 to two or three inches in thickness, very fissile — -some of the lower 

 layers are hard, and fine grained — when struck, emitting a metallic 

 sound, as if they had been subjected to a strong heat. No veget- 

 able remains have been seen in this stratum. — 15 feet. 



6. Fine plastic clay, nearly white ; a kw miles west of this local- 

 ity, the same bed is found with a much purer clay, and is used in 

 the manufacture of Pots for glass house furnaces. It supports a 

 great degree of heat. This vicinity abounds in clays very suitable 

 to the manufacture of earthen ware of various kinds. — 1 foot. 



7. Stratum of shelly ash colored limestone, with a tinge of yellow 

 decomposing very readily into marl. It seems to be made up of de- 

 composed and broken, and also of many whole shells, of the same ge- 

 nera, and generally of the same species with those found at " Flint 

 ridge," a few miles west of this spot, in a calcareo-silicious deposit, 

 abounding in cellular quartz, with veins of chalcedony, and furnishing 

 a material for mill stones equal to the best imported Paris Burrh 

 stones — a further description of this interesting deposit, which lies 

 at an elevation somewhat greater than this, will be given hereafter. 

 The figures of shells Nos. 1, 2, 3, 4, 5, 6, 7, 9, 10, (page 2 of the 

 wood cuts, and fig. 8 on page 3,) are from this bed, a description of 

 which may be given in the appendix. No. 1 1 , (page 2,) is an impres- 

 sion very common in this bed of limestone. The stellated points are 

 of a greenish hue and appear to be connected by a fine striated sub- 

 stance. It is probably a species of Gorgonia, but the fragments of 

 stone are too small to give its original figure or outlines. The spines 

 of a species of Plagiostoma, are very abundant in some parts of 

 the bed. The perfect shell is found near Columbia in compact 



