458 On the Agricultural Geology of England and JVales. 



and has pointed out the geology of the surface as of more imme- 

 diate importance to agriculture than that of the rock formations. 

 He has declared that Agriculture now requires " maps of her 

 own," — maps which shall exhibit the extent and composition of 

 the superficial deposits ; and that notwithstanding the useful 

 labours of the Government Geological Survey, the construction of 

 maps of the superficial deposits, which should show the agricul- 

 tural capabilities of different districts, based on a knowledge of 

 their soils and subsoils, and the sources from which they have 

 been derived, whether near at hand or remote, is a work well 

 worthy the patronage of our leading Agricultural Associations. 



Course of investigation required. — The true inductive method 

 liy which to determine the relative influence of the rocks and the 

 superficial deposits on the character of the soil, requires that the 

 variations of the latter should be laid down on the scale of our 

 best geological maps, and that the information should be noted 

 which is furnished by every available section respecting the 

 mineral character of that which, though the real substratum, is 

 the assumed surface of those maps. The depth and composition 

 of the various beds belonging to the superficial deposits between 

 such stratum and the soil, should also be indicated. We are not 

 aware that more than two attempts have been made in England 

 to collect this information. The first was a map of the soils of a 

 large portion of Norfolk, undertaken as the basis of a paper on 

 the geology of that county, as illustrative of the laws of the distri- 

 bution of soils, which was published in the Seventh Volume of 

 the Journal of the Royal Agricultural Society. The other was 

 a map of part of South Wales, constructed on the same plan, for 

 the Government Geological Survey. In both these cases the 

 variations of soil were found to be mainly dependent on other 

 conditions than the composition of the subjacent rock. The 

 author of those maps has acknowledged that the idea of con- 

 structing the first of them was suggested by the passage above 

 referred to in the Lectures of Professor Johnston ; who has him- 

 self produced two maps, the one agricultural, the other geological, 

 appended to a Keport on the Agricultural Capabilities of New 

 Brunswick," which was made during his recent visit to America, 

 and published by the Colonial Legislature. 



The only means at present existing for submitting the whole 

 of England and Wales to the test proposed, is by collecting such 

 information as geology furnishes respecting the distribution of the 

 superficial deposits, together with such still less perfect informa- 

 tion as can be obtained from the Reports to the Board of Agri- 

 culture and other Agricultural writings respecting the distribution 

 of soils, comparing the results thus obtained with our best geolo- 

 gical maps. 



