KINDS OF SOILS. 55 



cracks. Place a lump of wet clay in the oven, and it 

 will dry quite hard like stone. Put it directly in the 

 fire, and it will turn to a red, brick-like lump. 



Place some of the wet clay in a saucer or flower-pot, 

 and scatter fine seeds upon it, as in our other experi- 

 ment. The seeds may sprout, and try to grow ; but 

 they will probably soon perish, as their tender roots 

 are unable to push their way into the sticky clay. 



After all these experiments have been performed 

 with the clay and sand, another interesting experiment 

 can be made by drying both the sand and clay, and 

 then mixing them together in equal parts. When well 

 mixed, place in a flower-pot, and scatter seeds upon 

 the mixture. Water well, and place in a sunny win- 

 dow ; and the plants will sprout, and grow longer and 

 better than in either the clear sand or pure clay. 



These experiments with the lump of clay show us 

 that if a soil consists wholly of clay, it must be a poor 

 place for plants. In every rain the water, instead of 

 sinking in the soil to supply the plants, would run away 

 over the surface and be wasted. After the shower 

 had passed, the soil would remain wet for a long time. 

 The sun would dry the soil very slowly, and when dry 

 the soil would split and crack, and tear the tender 

 roots of plants growing in it. The sticky, paste-like 

 soil would cling to our spades and ploughs, and we 

 should find it hard, slow work to cultivate the ground. 

 It would be a wet soil, and, as a result, a cold soil. 

 This was proved in every experiment with the wet 

 clay, for it felt at all times cold in the hands. A clear 



