RATIONAL FRUIT CULTURE. 25 



they also differ physically — in the size of their particles, those 

 of clay being much smaller, and therefore fitting more closely 

 together than those of sand — and for this reason their effects 

 differ considerably. When soil consists of not less than 80 

 per cent, of clay, the rest being sand, it is called clay; when 

 the proportion of clay falls to from 60 to 80 per cent., it is 



Fig. >. — Glasses of water, with samples of soil. On tite left nearly equal proportions of 

 sand and clay; on the right mostly clay. 



clay-loam; when the proportion falls still more, to from 40 

 to 60 per cent., it is loam; with only 20 to 40 per cent, of clay, 

 it is sandy loam; and with less than 20 per cent, of clay, 

 it is sand. If a handful of soil is mixed with water, shaken 

 up well, and allowed to settle, the particles of sand will sink 

 to the bottom, and then the smaller particles of clay will 

 form a layer on top. In this way, their relative proportions 

 can be determined. 



