NORTH-CAROLINA GEOLOGICAL SURVEY. 25 



Soda, 0.03 



Sol. silica, 0.20 



Water, 8.90 



Phosphoric acid, trace. 



99.44 



These remarks are justified on comparing the results of this 

 analysis with Dr. Long's soil, which has been under cultiva- 

 tion only three years ; thus, the silica is in greater proportion, 

 and the organic matter, less ; and it is due no doubt to the 

 fact that it has been under cultivation for the time specified. 

 It still retains, however, a magazine of food for future crops ; 

 and if not exhausted at a greater rate than during the last 

 century, it will be a rich soil at the close of the next century. 

 It will be perceived that all the elements of fertility which 

 belong to new and unexhausted soils still belong to this. The 

 inorganic matter is extremely fine, like the finest grit, and in 

 the proportion required for the production of the most valua- 

 ble crops. Growing, as we perceive, in a magazine of food, 

 it seems to show that it is a crop upon which it is scarcely 

 possible to overmanure, and that it is unlike other corn crops, 

 which, when over supplied with food, run to stalks and leaves 

 to the detriment of the grain. 



17. If we calculate the amount of inorganic matter which 

 a hundred crops of maize remove from the soil, we should 

 find it to amount to many thousand pounds. 



From data in my possession, I am led to believe that five 

 hundred pounds per acre of inorganic matter is removed in 

 every crop. This inorganic matter is contained in the ker- 

 nels, cobs, husks, silks, leaves, sheaths, stalks and tassels ; 

 each organ containing its own appropriate amount: 



The number of plants which are allowed to grow upon an 

 acre, amount to fourteen thousand and seven hundred. Each 

 plant removes from the soil a specific amount of the earthy 

 compounds, and nearly in the following proportions, viz : 



In Silica, 195 Ibs. 



Earthy phosphates, 108 " 



Lirne, 25 " 



Magnesia, 18 " 



