THE OLIVE 51 



Absorbtioii is o^reater by iiioht than bv dav. and recently cultiva- 

 ted ground is the most receptive, as it exposes the greater number 

 of particles to the action of the air. 



As the earth grows dry. its caj^acity to absorb moisture diminish- 

 es. So we observe that ground frequently and thoroughly cultiva- 

 ted retains moisture the lonsfest. 



THE DRYIXG QUALITY OF SOILS. 



Of 100 parts 

 of water. 



Silicious sand in four hours evaporates 88.4 



Calcareous '' " " " " 75.9 



Gypsum " " " " 71.7 



Drv chalk " " " " 52.0 



Earthv " " " " " 45.7 



Clavev soil " " " " 34.6 



Clay " " " '' 31.9 



Carbonate of lime in four hours evaporates 28.9 



Manure " " '' " 20.5 



Magnesia '' " ' " " 10.8 



Garden earth " " '' " 24.3 



Arable hand " " "■■ '' 32.0 



These figures indicate what we see in practice, that the more 



sandv the soil, the sooner it dries. Some soils when thev drv, actu- 



ally diminish in volume, and through splits and cracks expose the 



roots of the tree. Sandy, limey and gypsum soils do not have this 



drawback ; the others vary in the following degrees. 



Of 1000 parts. 



Carbonate of lime soils loses 50 



Drv chalk " " 60 



Earthy " " " 89 



Clayey soil " " 114 



Clay " " 183 



Magnesia u u ^-^ 



Manure " " 200 



Garden earth " " 149 



Arable land " " ' " 95 



