446 On the Agricultural Geology of England and Wales. 



for their attainment by the present state of geological and agricul- 

 tural knowledge respecting the composition and distribution of 

 soils. 



This essay will, therefore, treat of the objects of agricultural 

 geology, and its present defective state, arising from the neglect 

 of the superficial deposits. In tracing the rise and progress of 

 the application of geology to agriculture, the probable cause of 

 this defect will be indicated. The distribution of the superficial 

 deposits or erratic tertiaries will be described ; its dependence on 

 the position and direction of the chains of hills; the peculiar 

 characters of these deposits ; their depth and composition ; the 

 heights to which they extend, and the districts most free from 

 them. Such information respecting the distribution of soils as 

 can be obtained from the Reports to the Board of Agriculture, 

 and other agricultural works, will then be brought under view, in 

 order to test the accuracy of the prevalent opinion that the varia- 

 tions of soil are dependent on the composition of the strata on 

 which they rest. 



In the course of these investigations we shall enter as little as 

 possible into what some may regard as geological theories. It 

 will, however, not always be possible, even if it were desirable, to 

 describe geological facts, without some allusion to conclusions 

 drawn from them respecting the agencies by which, and the 

 periods at which, the phenomena described were produced. To 

 those, moreover, who are "anaccustomed to geological investiga- 

 tions, much will appear speculation which is in reality well esta- 

 blished fact ; such as the succession of the stratified rocks ; the 

 successive distinct assemblages of plants and animals contained 

 in them ; the aqueous origin of some rocks, the igneous origin 

 of others; mountain chains formed at different epochs by dis- 

 ruption and upheaval of the strata along different lines ; and 

 repeated elevations and depressions of the same areas above and 

 below the sea-level. 



Objects of Agricultural Geology. — A knowledge of soils, sub- 

 soils, and substrata, constitutes the science of agricultural geology. 

 Its objects are — 1. The classification of soils on a sound and 

 accurate basis, and the establishment of some general nomen- 

 clature of them for that Babel of local names which renders it 

 nearly impossible for the cultivator of one district to know the 

 nature of a soil on which a given process of cultivation has been 

 found successful or unsuccessful in another. 



2. Agricultural geology should be able to impart a know- 

 ledge of the laws of the distribution of soils ; that is to say, 

 where soils of a gi^•en quality, or adapted to a given system of 

 husbandry, are to be found ; whether each formation yields a 

 peculiar soil which is co-extensive with the area allotted to it on 



