31 



I. Relations of Geology to Agriculture. 



From any one of these general topics, I might select 

 beautiful examples of the close bearings of science upon 

 profitable farming — but time does not permit me to illus- 

 trate in detail any one of the general relations to which 1 

 have referred. A few observations, however, in reference 

 to the special applications of Geology and Chemistry, will 

 neither detain us long, nor prove, I believe, generally 

 uninteresting. 



In reference to Geology, I could have wished to point 

 out to you the very close economical connection which 

 recent discoveries have established between practical geo- 

 logy and practical agriculture — how the manufacture and 

 abundance of valuable manures, for example, is actually 

 dependan t on the progress of geological discovery. I rnust 

 be content, however, with a brief allusion to the geology 

 of the United States. 



There are few countries, indeed, which more clearly 

 than your own, show the relations which geology bears to 

 agriculture in all its branches. Your wide prairies are na- 

 turally dsitinguished from your vast forest lands, by the 

 character of their soils, and these again by the geological 

 structure of the regions over which they extend, and from 

 which they are generally derived. The broad treeless zone 

 of calcareous marl, or rotten limestone — called the prairie 

 or cane brake country — which crosses Alabama in an east 

 and west direction,* owes its natural nakedness to the dry, 

 waterless, chalky deposits, which for a depth of hundreds 

 of feet form the uppermost rocks of the country ; and the 

 tenaceous, soapy, unctuous quality of the soils, with which 

 the carriage wheels of travellers in that State, in wet wea- 

 ther, become familiar, is owing to the same cause. 



* Lyell's Second Visit to the United States, p. 42, 89. 



