EFFECTS OF GOOD CULTURE. 141 



operate wholly to the disadvantage of the dark soils, for as 

 the cooling progresses most rapidly the dew is deposited 

 with equal facility ; and it is doubtful if this accession of 

 moisture may not be of greater benefit to a ^parched soil 

 than the longer retention of the warmth might be. Besides 

 as the dark soils become heated more abundantly than oth- 

 ers, they can better spare their excess of heat than lighter 

 soils can, and yet have an abundance remaining for every 

 need of the crops. 



Such then are, in the main, the most important physical 

 properties of the soil. Over much of them the intelligent 

 farmer has easy and effective control as will be explained in 

 a future chapter. He can drain land that is excessively wet 

 or which is sealed below by an impermeable subsoil and thus 

 open it to the beneficent influence of the vitalizing atmos- 

 phere with all its burden of fertilizing agencies; and to the 

 vivifying influence of the suns heat. He can plow and pul- 

 verize it and make it more open and porous and so give ef- 

 fect to its chemical influences over such organic matter as it 

 may contain as will more quickly prepare it for the aliment 

 of the crops. He can stiffen and darken the lighter sandy 

 soils and loosen and soften the heavier clay, by mixing com- 

 posts or manure with them and thus make either more val- 

 uable for his purposes. 



But while the physical properties of the soil have much 

 to do w r ith its productive power, these are only secondary 

 and helpful to its primary condition of fertility. It may be 

 neither too heavy nor too light; too wet nor too dry; too 

 cold nor too warm; too fine nor too coarse; too high nor 

 too low ; may be situated in the most propitious climate; 

 and consist of a well proportioned mixture of sand and clay ; 

 contain an average quantity of vegetable matter and have 

 every benefit of a warm and favoring locality; and yet it 

 may disappoint the expectations of the farmer or be wholly 

 barren. The want of one of the indispensable elements of 

 plant food in it may forbid the growth of one spear of grass, 

 and make of it a barren waste. Therefore the physical prop- 

 erties of the soil are only accessory to its chemical consti- 



