JVotkes of the Florid as ^ &fc. 125 



A rolling tract of comparatively elevated ground, a 

 continuation of Georgia and Alabama ridges, passes in an 

 eastern direction, through the centre and northern part of 

 West Florida, thence bends to the south-east into East 

 Florida, dividing the waters that fall into the St. Johns and 

 Gulf of Mexico and terminating between the Bay of Espi- 

 ritu Santo and Charlotte harbour, and occupying in Flori- 

 da, an extent of near 400 miles, with an average width of 

 thirty. It presents the most diversified scenery afforded in 

 the southern part of this country, an alternation of hills often 

 of considerable elevation, and good soil, lakes, extensive 

 prairies, savannas and pine plains. 



This rolling district is principally of secondary forma- 

 tion. Ledges and beds of limestone and siliceous rock 

 appear in many parts. Numerous sinks, caves and subter- 

 ranean water courses peculiar to calcareous tracts indicate 

 a basis of limestone. This rock occurs in sinks or circular 

 tunnel shaped basins, generally very steep, and often of 

 considerable depth, probably occasioned by a passage 

 opened by water into limestone caves — these sinks are nu- 

 merous and observed in every part of the hilly country of 

 Florida. Some have perpendicular walls of limestone, 

 with a decomposing surface embracing marine shells, oth- 

 ers have wells of pure water. Near the Indian village of 

 San Falases at the bottom of a deep sink is a natural well 

 about three feet in diameter; its limestone border is circu- 

 lar, vertical, and well defined, it was filled with pure water. 

 Sinks border most of the lakes and savannas, affording an 

 outlet for the waters. In a section of the hilly district of 

 East Florida called Alachua, I visited a sink filled with 

 water, covering an acre. It is the outlet of a mill-stream 

 that winds through a handsome prairie, and plunging into 

 the rocky basin takes a subterranean course — ledges of 

 calcareous and siliceous shell rock formed the banks of the 

 pool. Rocks in situ and detached, enclosing in a white 

 siliceous matrix, siliceous petrifactions of marine shells 

 were frequently noticed in this vicinity. This mineral 

 gives fire copiously with steel, and no effervescence is pro- 

 duced by acids applied to a recent fracture, and on minute 

 division it appears entirely siliceous. A siliceous petrifac- 

 tion of madrepores retaining no calcareous particle, but the 

 cells perfect, and the stone white as coral rock in its na- 



