J. Hendrick and W. Gr. Ogg 459 



much in different parts of Britain. In places it attains a thickness 

 of over two hundred feet, and quite near may be areas from which it 

 is absent altogether. In some parts it consists of the old soils and 

 subsoils of the original land surface; in others of the ground-down 

 portions of igneous, metamorphic, and very ancient stratified rocks, 

 and between these extremities there are all intermediate stages. Thus 

 the drift of the South-east of England— the Clay-with-Flints, for 

 example — is very different from the drift of the North of Scotland, 

 the one being derived fiom the old surface soil and late fornuitions, 

 while the other is largely the ^iroduct of the granitic and metamorphic 

 rocks of the Scottish Highlands. Soils of this latter type cover a, great 

 part of North Britain, and Craibstone furnishes a typical specimen of 

 the Northern Drift Soil. 



Geiiiriil rn))ij)()sih(iii (if llir Diittendl. 



The sample used in these investigations was obtained from the 

 South Meethill Field at Craibstone which is being used for field experi- 

 ments, and in which lysimeters have been built to study the drainage. 



The sample used was taken to a depth of nine inches, air dried, 

 and freed from large stones. 



The methods of analysis (mechanical and chemical) were, except 

 where otherwise indicated, those adopted by the members of the 

 Agricultural Education Association. 



The calcium carbonate present and the "lime requirement" were 

 determined by the methods of Hutchinson and MacLennan'. 



From the mechanical composition it will be seen that the soil under 

 investigation is a coarse sandy soil comparatively rich in organic matter 

 and poor in clay. In determining clay, the liquid was evaporated in 

 bulk and therefore much organic matter dissolved by ammonia was 

 present and was estimated as clay "dried at 100° C," but even with 

 this included, the total was less than 9 per cent. That this is a great 

 overestimate is shown by the fact that after ignition the weight, i.e. 

 the ignited mineral matter of the clay, is less than 4 per cent, of the 

 dry soil. 



The chemical analysis shows the soil to be rich in phosphoric acid 

 and potash both ''total" and "available." 



It contains no carbonate of lime, and has a high "lime require- 

 ment," but in spite of this, good crops have been grown for many 

 years without the application of lime. 



> Joiint. of Agric. Sc. 1914, 6, 323-327: 1915. 7, 75-105. 



