274 THE FLORIST AND 



can understand the cause or not, that his drained land is much drier in a 

 wet time, and more humid in a dry time, than his unci rained land, and that 

 it will stand a drought very much better; in fact, that droughts seldom af- 

 fect his well drained land. Let us examine this a little. 



If you take a common sponge, and dip one end into a basin of water, the - 

 whole sponge will become thoroughly saturated, the water rising very far 

 above its own level. If you take a narrow glass tube, open at both ends, 

 and plunge one end into water, you will observe the water rise, contrary to- 

 the law of gravitation, much higher in the tube than the external surface of 

 the water. Dr. Hook, when experimenting on this subject, made glass tubes 

 so fine that the water rose in them twenty-one inches above the level of the 

 water in the vessel. The law by which it rises is called capillary attraction, 

 and is explained thus: the particles of water have a stronger affinity for the 

 glass than for other particles of water, and consequently leave them and 

 ascend the glass. The height to which they will ascend is probably in the 

 inverse ratio of the diameter of the tube.. 



When a soil, especially a retentive one, is underdrained, the water as it 

 percolates through it leaves innumerable small pores ; it becomes like a 

 sponge — a reticulated mass of fine tubes. These tubes, when the surface is 

 wetter than the subsoil, carry down the water to the drains below ; and 

 when the surface is dryer than the subsoil, as it is in a drought, tbese tubes 

 carry up the water to the roots of plants. Underdraining is not built on 

 this theory, but the theory is founded on the practical results of underdrain- 

 ing, and will the more commend itself to practical farmers. 



Plants can take their food only in a state of dilute solution. They can- 

 not live and grow without a constant supply of fresh water. Stagnant wa- 

 ter is exceedingly deleterious ; no fact is better demonstrated than that agri- 

 cultural plants cannot thrive, however well manured, so long as their roots 

 are surrounded with stagnant water. The necessity for underdraining rests 

 on these three facts. Not only does underdraining remove all excess of wa- 

 ter, and supply it when deficient, but it equalizes the temperature of the 

 soil. In the spring and fall, when a warm soil is so much needed for the 

 germination and maturation of seeds, the thermometer shows that an under- 

 drained soil is several degrees w r armer than one that is not drained ; while 

 in very hot weather, the case is exactly the reverse of this. It is a well 

 known fact that vegetation starts much earlier in the spring, and continues 

 later in the fall, on a drained than on an undrained soil. 



But beside the beneficial mechanical effect on the soil, underdraining has 

 great chemical action. The removal of stagnant water and the free admis- 

 sion of air in its stead, accelerates the disintegration of minerals as well as 



