[155 j 



leaves are very different in different vegetables, so they 

 flourish most in different soils : the plants that have 

 bulbous roots require a looser and a lighter soil than 

 such as have fibrous roots ; and the plants possessing 

 only short fibrous radicles demand a firmer soil than 

 such as have tap roots, or extensive lateral roots. 



A good turnip soil from Holkham, Norfolk, af- 

 forded me 8 parts out of 9 siliceous sand ; ani the 

 finely divided matter consisted 



Of carbonate of lime - - 63 



silica - - 15 



alumina 11 



oxide of iron - 3 



vegetable and saline matter 5 



moisture - 3 



I found the soil taken from a field at Sheffield- 

 place in Sussex, remarkable for producing flourishing 

 oaks, to consist of six parts of sand, and one part 

 of clay and finely divided matter. And one hundred 

 parts of the entire soil submitted to analysis produced 



farts. 

 Silica 54, 



Alumina - - 28 



Carbonate of lime - 3 



Oxide of iron 5 



Decomposing vegetable matter - 4 



Moisture and loss ... 3 



An excellent wheat soil from the neighbourhood 



of West Drayton,. Middlesex, gave 3 parts in 5 of sili- 



