ENGLISH AGRICULTURE. 59 



Soils derived from the mixing of lower chalk with upper 

 greensand are usually of high average fertility. Soils derived 

 from the London clay formation mixed with soils derived 

 >m the Suffolk or Norfolk Crag are generally richer than 

 >ils derived solely from the London clay. The mixing of 

 ie rocky debris of two or more formations in the production 

 a soil is favourable, and very generally gives a strip or 

 3gion of fertile ground. It is the same principle no doubt 

 gives the value to alluvial soils. They have been 

 rough t down by the river as it cuts its way through a 

 lumber of different formations, so that the washings of many 

 :inds of soil are brought together, arid a high standard of 

 utility is the result. This is a point of some importance in 

 >nnection with the bearings of geology upon the distribution 

 soil. 



Let me, in the next place, enforce the importance of care 

 using geological knowledge as a means of predicating the 

 laracter of soils. I am aware that the London clay is a 

 jnacious, fine-grained soil. It may be seen to be such on 

 the north of London, towards Harrow, and it is certainly 

 striking fact that so much ground there lies in permanent 

 sture. It is remarkable in such close proximity to a vast 

 >pulation, but it is accounted for by the retentive character 

 >f the "ground, which is best suited for pasturage and 

 reducing hay for the London market. 



In Essex the London clay reigns paramount, and perhaps 

 10 county has suffered more severely from the recent fall in 

 the value of cereals than Essex. 



The student is in some danger of rushing to the conclusion 

 that when the London clay forms the predominant element 

 re must necessarily find a clayey soil. The London clay 

 >rmation is, however, liable to interruptions, and is not 

 exclusively a clay formation. The Bracklesham beds and 

 the Bagshot sands form part of the great formation which 





