74 THE UPPER PINE BELT. 



amendment to the soil. Quantities of excellent lime were also obtained 

 from them by burning, especially by Dr. Jamison, on Caw Caw swamp. 

 The green sand marls intercalated with them contain 30 per cent, of car- 

 bonate of lime, and 22 per cent, of green sand. 



The marls of Sumter and Darlington, examined by Mr. Tuomey, were 

 found to contain 60 to 70 per cent, of carbonate of lime, with traces of 

 phosphate of lime. Larger quantities of the latter are said to have been 

 found here since attention has been directed to the value of phosphates. 



SOILS. 



The upper pine belt contains something over 6,000 square miles, about 

 one-sixth of which is swamp and the remainder uplands. 



The uplands consist of a fine, light, gray, sand}^ loam, resting on a sub- 

 soil of red or yellow clay. In the east, in Marlboro and Marion, it is 

 usually found at only three inches to four inches. In the west it is often 

 deeper, and a subsoil of yellow or red sand intervenes between it and the 

 surface soil ; even here the depth to clay is seldom as much as two feet. 



The following are the anal3'ses of these soils, made by Eugene A. Smith, 

 of Alabama, for the Tenth United States Censi?is : 



Insoluble matter .... 93.695 



Soluble Silica 1.483 



Potash 0.076 



Soda 0.060 



Lime 0.114 



Magnesia 0.202 



Bn. Oxide of Manganese . 0.020 



Peroxide of Iron .... 0.737 



Alumina 1.846 



Phosphoric acid 0.036 



Sulphuric acid 0.106 



Water and organic matter 1.771 



Total 100.146 



Hydroscopic moisture @ 



75° F 2.512 



No. 1 is from the Johnson field, on the Cathwood plantation of P. F. 

 Hammond, in Aiken county, near the Savannah river, the soil being taken 

 uniformly, as all the samples were, to the depth of twelve inches. The 



