SOILS. 



53 



and forced it into fields and patches in hollows, low vallies, 

 &c. If the relics contained in the shell-marl should be consid- 

 ered as those of fresh water, it might render the hypothesis 

 more complicated ; but I cannot perceive that it would be a 

 substantial objection. 



SOILS, 



j9s wjluencing the growth of Vegetables. 



An error of importance had prevailed among geologists, on Prevailing 

 the subject of the origin of soils, until a classification of detri- 

 tus was established. Cuvier's theory of the earth did much to- 

 wards the present improved state of that department of geolo- 

 gical knowledge. But Schoolcraft suggested the first thought fil^'t^'^.u-'^^* 

 ever published, on a classification, which is in accordance with g^^^^^ed the 



distinclion 



the present views of geologists on that subject ; though his no- between 

 menclature was different.* Near the same time Conybeare, dTluvion.^" 

 Buckland, and others, gave a character to it, which will en- 

 dure. 



It seems to be demonstrated, that anti-deluvial detritus (cal- Tertiary 

 led the tertiary formation) is a deposite, as independent and dent"depo"" 

 distinct, as secondary rocks. It cannot be traced immediate- 

 ly to any adjoining rocks. Consequently its character cannot 

 be explained by referring to other strata ; unless we admit the 

 general principle that all deposites, made after the deposition 

 of the lower part of the argillite, consist of fragments of the 

 older rocks. 



The principle heretofore received then, that soils depend for 

 their constituent characters on underlaying rocks, cannot be 

 received any farther than as applied to analluvion. All other 

 kinds of soil have characters as independent as transition or se- 

 condary rocks ; and they may be classified now, with as much 

 accuracy. 



See my index to the Geology of the P^orthern States, 2d ed. 1820. 



