The Soil 



sandy soil with a mixture of clay, which is 

 the most productive and most easily cul- 

 tivated. Its fertility is increased if it is 

 inundated by floods; for the river leaves 

 behind a fertile mud formed of clay and 

 organic matters carried by the water. 



Heath land is a soil composed of fine sand 

 and humus supplied by the decay of heaths 

 and other plants. It is also used for the 

 cultivation of garden flowers. 



Clay is an earth which when kneaded with 

 water turns into a firm and flexible paste, 

 which can be moulded into any shape. When 

 perfectly pure it is white. This is kaolin, a 

 very rare substance used for the manufacture 

 of porcelain. Plastic clay is oily to the 

 touch and forms a pliable paste when mixed 

 with water. It becomes very hard when 

 baked in the fire and is used for pottery. 

 Other clays produce a paste which is not 

 pliable and which readily absorbs fats. 

 These are used in manufactures to remove 

 from cloths the oil used in weaving them. 

 Ochres are clays coloured red or yellow by 

 rust, which are used in rough painting. Marls 

 are composed of clay and chalk in varying 

 proportions. These marls disintegrate, or 

 fall into powder, under the influence of air 



63 



