90 



BRITISH PLANTS 



Comparison between the Physical Properties of Sand and 



Clay. 



Clay. 



1. Particles small. 



2. Individual air-spaces small; 

 total pore-space large. 



3. Cohesion great. 



4. Soft and greasy to the touch 

 when wet. 



5. Maximum water - capacity 

 great. 



6. Amount of hygroscopic water 

 great. 



7. Water - retaining capacity 

 great. 



8. Almost impermeable to 

 water. 



9. Capillarity great. 



10. A wet soil. 



11. A cold soil. 



12. When dry, is hard and 

 cracks. 



13. Drainage difficult. 



14. A fertile soil, since it is diffi- 

 cult to wash soluble matter out 

 of it. 



15. A heavy soil, hard and ex- 

 pensive to work. 



Chalky soils occupy an intermediate position — in some 

 characters more approaching sand, in others clay. The 

 best soil is that which, while light and warm, is fertile in 

 plant-food, and contains plenty of water, without appear- 

 ing wet. No one of the above soils fulfils all these con- 

 ditions, but by suitably mixing sand, clay, and chalk 

 together a loam is obtained which answers most of these 

 qualifications fairly weU. 



Sand. 



1. Particles large. 



2. Individual air-spaces large; 

 total pore-space small. 



3. Cohesion of the particles very 

 small. 



4. Firm and gritty to the touch. 



5. Maximum water - capacity 

 small. 



6. Amount of hygroscopic water 

 small. 



7. Water - retaining capacity 

 small. 



8. Very permeable to water. 



9. Capillarity small. 



10. A dry soil. 



11. A warm soil. 



12. When dry, is friable and 

 does not crack. 



13. Drainage natural and easy. 



14. A sterile soil, since soluble 

 matter is easily washed out of it. 



16. A light soU, easy to work. 



