334 On the Secondary and Tertiary Formations. 



and sometimes by layers of gravel. From its position only on 

 high hills, and want of fossils, I consider it to belong to the dilu- 

 vium spread over the country after its elevation above the sea, 

 most of which has been subsequently washed and worn away 

 by long continued degradation. 



Near the Roanoke, some miles above Williamston, I observed 

 the marl by the road-side, and although it was hard frozen and 

 nearlj'" covered with snow, I recognized in it many individuals of 

 our common recent shell, the Venus mercenaria. This is a very 

 poor part of North Carolina ; the land is quite flat and sandy, and 

 during the winter season one frequently rides for miles through 

 water several inches deep, by which the roads are flooded. 

 The principal growth is the pitch pine, from which a great deal 

 of tar and turpentine are made. The woods along the roads 

 present a singular appearance, every tree being half stripped of 

 its bark to the height of seven or eight feet, and the exposed 

 surface bleached by the white turpentine oozing out. A little 

 cavity is hollowed out at the base of the trunk, into which 

 most of the turpentine runs, and the remainder is scraped off 

 and put into barrels. The tree dies and becomes fat pine. This 

 is burned in pits, as wood is for charcoal, and the tar runs out 

 upon the carefully prepared clean floor. North Carolina tar is 

 inferior to that made in Norway, owing probably to less pains 

 being taken in the preparation. It is sent principally to the 

 north, where it sells for about a dollar and a half per barrel, but 

 the makers receive only ninety cents, out of which they pay 

 twenty-five for the barrel. 



In the very western part of Jones county, I first met with the 

 limestone of the secondary formation. It is on the plantation 

 of Mr. Humphreys, at the heads of New river and Trent river. 

 The rock lies in a heavy ledge on the borders of a swamp ; its 

 surface is much worn and ragged. It is of a straw color, and 

 apparently of good quality for making lime ; — on submitting a 

 piece to chemical examination, I find it as good as the limestone 

 of this formation usually is. It yielded in 100 parts, 



Water, 1.00 



Silica, 5.60 



Iron and al., 5.60 



Carb. lime, 87.00 



Carb. mag. trace 



"9020 



