202 PRACTICAL AGRICULTURE. 



cools as much in an hour as a clay soil in an hour and 

 twenty minutes, or a sandy soil in two hours. 



FINENESS WITH WHICH SOILS ARE DIVIDED. 



383. Some soils are more finely divided than others. 

 The degrees of fineness may be compared by sifting 

 dried soils through a coarse sieve. The finer they are 

 the better, if their chemical composition is the same. 



ADHESIVENESS OF SOILS. 



384. When soils are wet, they are more adhesive 

 than when dry ; and those which are clayey are more 

 adhesive than those which are sandy. The particles 

 of the former adhere to each other, forming hard 

 lumps, while those of the latter readily crumble in 

 pieces. It follows, that of two soils, equally produc- 

 tive, one may be cultivated at a profit, because it can 

 be worked at a small expense ; while the other, being 

 expensive to work, 'cannot be cultivated but at a less 

 profit. 



POWER OF ABSORBING MOISTURE. 



385. This quality of soils may be compared by dry- 

 ing a quantity of different soils, and then exposing 

 them to the air. If you dry a soil as dry as it can 

 be made, by spreading it on a piece of sheet-iron, and 

 holding it over boiling water, or by p^itting it into an 

 oven of about the temperature of boiling water, and 

 then exposing it to the air, it will be found gradually 

 to increase in weight, in consequence of the water it 



