CHAPTER I 



WHAT 18 THE SOIL MADE OFi 



Apparatus required. 



Soil and subsoil from a hole dug in the garden. 

 Clay, Six tripods and bunsen burners or spirit 

 lamps [2]. Six crucibles or tin lids and pipe-clay 

 triangles [2]. Twelve glass jars or gas cylinders [4], 

 Six beakers [2]\ 



If we talk to a farmer or a gardener about soils he 

 will say that there are several kinds of soil ; clay soils, 

 gravel soils, peat soils, chalk soils, and so on, and we 

 may discover this for ourselves if we make some rambles 

 in the country and take careful notice of the ground 

 about us, particularly if we can leave the road and walk 

 on the footpaths across the fields. When we find the 

 ground very hard in dry weather and very sticky in wet 

 weather we may be sure we are on a clay soil, and may 

 expect to find brick yards or tile works somewhere 

 near, where the clay is used. If the soil is loose, drying 

 quickly after rain, and if it can be scattered about by 

 the hand like sand on the sea shore, we know we are on 

 a sandy soil and can look for pits where builder's sand 

 is dug. But it may very likely happen that the soil is 

 something in between, and that neither sand pits nor 



* See p. ziv for explanation of the figares in sqaare brackets. 

 R. 1 



