NORTH-CAROLINA GEOLOGICAL SURVEY. 9 



and carbon. They do not seem, in any instance, to enter 

 into the composition of living bodies in the elementary state, 

 but as compounds ; thus hydrogen combines with oxygen 

 and forms water, or nitrogen and forms ammonia ; oxygen 

 combines with phosphorus, sulphur, etc., before they are 

 fitted to enter into the composition of the animal tissue. 



The soil then, being the great reservoir or source of these 

 elements which are truly essential to life, and so far as nutri- 

 ment is concerned are dependent upon them, we cannot over- 

 estimate the importance of preserving it in the best condi- 

 tion ; and when the soil is so far deprived of these elements 

 that the crops are imperfect, we see the importance of those 

 fertilizers which contain them. It appears also, that sub- 

 stances which do not contain them, have never been denomi- 

 nated fertilizers at all. Hence, when matters are added to 

 soils, it is expected that they contain more or less of phos- 

 phorus, sulphur, potash, soda, etc., in certain states of combi- 

 nations which the plant is able to obtain. 



6. The soils of North-Carolina are remarkable. They 

 belong very frequently to the extremes of certain well dis- 

 tinguished classes. On the one hand, these extremes consist 

 of sand, a marine product, nearly pure, or with only a trace 

 of other matters ; on the other, they are composed of nearly 

 pure vegetable matter, with only a trace of earth or soil 

 proper. These are not simply rare exceptions to the common 

 run of soils, but they form classes. So also the stiff clays 

 which are also marine deposits, form another class. These, 

 however, do not materially differ in composition from the 

 same class in other sections of the State. 



The two former, I believe, are sectional, and are confined 

 to the lower counties. 



Besides the foregoing, where rocks exist near or at the sur- 

 face, we may clearly recognize other classes which differ, both 

 as to their origin and composition. For example, we may 

 readily distinguish from all others the deep red soil of the 

 argillaceous slates from that of gneiss or granite, though the 

 latter has a deep red color also, or, from the deep red soil of 

 the sandstone of Orange, Chatham, Moore and Anson. There 



