15. GULF HAMMOCK REGION. 303 



Sulphuric acid -331% 



Brown oxide of manganese .134% 



Peroxide of iron -534% 



Alumina 1.196% 



Soluble silica 3-456% 



Insoluble matter 35-5557o 



Total 100.667% 



(The percentage of lime given corresponds to about 55% of calcium car- 

 bonate, or limestone). 



The so-called Wakulla volcano, a column of smoke which is 

 said to have been visible from Tallahassee and other high points 

 in that neighborhood during most of the 19th century, must have 

 been in this region. No one ever succeeded in reaching it, and it 

 remains, and probably always will remain unless it becomes active 

 again, entirely unexplained.* 



Topography and Hydrography — The whole region is less 

 than 100 feet above sea-level, and the surface is for the most part 

 level or nearly so; but there are some undulating areas with lime- 

 sink topography, scarcely distinguishable from the lime-sink re- 

 gion described farther on (no. 17). One such area, covering sev- 

 eral square miles at least, is in Taylor County, about half way 

 between Perry and the coast. As in most other parts of Florida, 

 shallow depressions of various sizes are very common. There 

 are natural bridges as well as rocky shoals on several of the 

 creeks and rivers a few miles from their mouths, but apparently 

 no caves or open lime-sinks, probably because the ground-water is 

 too near the surface in most places. 



Most of the streams have practically no valleys, the flatwoods 

 extending almost to their banks. f They are all sluggish, except at 

 the rocky rapids above mentioned, and most of thgm are coffee-col- 

 ored, like the majority of coastal plain streams. There are, how- 

 ever, several clear runs from limestone springs, which are rather 

 common along and near the inland edge of the region. Shallow 



*Perhaps the most reliable account of this phenomenon is in Norton's 

 Handbook of Florida, 3d edition (1892), p. 346. There is a wood-cut of it 

 and some descriptive matter, rather fanciful though, in the article by Barton 

 D. Jonas in Lippincott's Magazine for March, 1882, p. 221 (see bibliography), 

 and one of the chapters in Maurice Thompson's novel. "A Tallahassee Girl.'" 

 is based on it. 



tWhere the Atlantic Coast Line R. R. crosses the Steinhatchee River on the 

 boundary between Taylor and Lafayette Counties the rails are not perceptibly 

 lower over the stream than they are a mile or two away on either side. 



