452 Oa the Agricultural Geology of England and Wales. 



existence, subject to local modifications from climate^ from the 

 nature of the bottom, and from the depth of water — some animals 

 inhabiting muddy, some sandy, some rocky bottoms, and some 

 bemg peculiar to certain zones of depth. Smith's oolitic dis- 

 trict, moreover, was one in which the influence of the rock 

 formations on the soil is at or near its maximum ; and it is not 

 surprising that he should have assigned to them generally an in- 

 fluence which they really possess in some situations where the 

 superficial deposits are absent, and should not have made suffi- 

 cient allowance for the modifications produced, even under their 

 slightest developement, by those deposits which are generally 

 present to some extent or other. 



Of Smith's views, however, on this subject we know but little 

 directly. His great work was his Map of the Strata; and, though 

 a most voluminous writer of notes, he published scarcely any 

 books. Some who, availing themselves of the open liberality 

 with which he communicated the results of his researches, called 

 themselves his pupils, and some who, without even this acknow- 

 ment, appropriated his discoveries, over-generalised his over- 

 generalisations. Farey, the author of the Report to the Board 

 of Agriculture on Derbyshire, carried this to the extreme of 

 regarding shells as distinct species if they were found by him 

 in more than one formation ; thus involving himself, as Pro- 

 fessor Sedgwick has remarked, in the vicious circle of first using 

 organic remains for the identification of strata, and then using 

 strata for the identification of organic remains. In like manner, 

 Smith s views respecting the influence of the rock formations on 

 soils, which are known only to those who have conversed with 

 him or have heard him lecture, or who have access to his notes, 

 may have become engrafted on agricultural geology in a some- 

 what exaggerated form, for he was one of the first to point out 

 the difterence between the stratified rocks and the superficial de- 

 posits: and the influence of the latter on the soil is too palpable 

 in districts where they prevail to have escaped the notice of so 

 accurate an observer. 



From the time when Smith's active labours ceased little was 

 done in the prosecution of agricultural geology, till the publication 

 of Mr. ?vIorton's work on Soils,* if we except the slight notices 

 respecting the agricultural characters of the rock formations in the 

 " Outlines of the Geology of England and Wales," by Conybeare 

 and Phillips, and if we except also the Report on the Geology of 

 Cornwall and Devon by Sir H. De laBeche. These two counties, 

 but particularly the former, constitute a district in which the 

 superficial deposits are of limited extent, and in which a more 



* -'The Nature and Property of Soils,"' &c., by John Mortoi). 1842. 3rd edition. 



