300 THE PHILADELPHIA FLORIST. [No. 10 



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^recommend underground drains. Not so much for taking off water, pA 

 CJ 5 but as a means of increasing its retention in the soil, and allow an °(j 

 admission of air to the roots of plants. In gravelly and sandy soils, \ 

 draining in conjunction with deep cultivation will secure a more am- 

 ple and lasting supply of moisture in dry weather, and keep vegeta- 

 tion in a luxuriant condition. This may seem paradoxical, but it is 

 nevertheless true. The soil is rendered more porous, water perco- 

 lates freely into it, carrying nutritious mailer to the roots, air follows, 

 holding moisture in suspension, and when the surface supply fails, 

 this suspended moisture is again brought up by capillary attraction, a 

 principle in cultivation which is not sufficiently understood or recog- 

 nized. 



Clayey soils are still more improved by this system of underground 

 ventilation. A compact surface is formed immediately below the 

 cultivated soil, which forms a perfect basin for the retention of water 

 to the exclusion of atmospheric gases. The strongest clays have 

 their "weak points;" here we find a natural crack, and there a vein of 

 sand; here again' a bit of gravel and there a stratum of decomposed 

 vegetable matter; so long as there is no vent underneath, these re- 

 main comparatively inactive, but c undermine |them with drains, and 

 their action is at once apparent, the subsoil that before held water as 

 in a basin, now transmits it like a filter. As the water sinks into 

 the soil a supply of fresh air immediately follows. From the in- 

 creased porosity of the soil the water that falls from the clouds con- 

 veys the ammonia, and carbonic acid to the roots of plants, which it 

 has absorbed during its passage through the atmosphere. The air ad- 

 mitted disintegrates and decomposes the mineral ingredients in the 

 soil, rendering them soluble and fitted for absorption by vegetation. 

 There are, perhaps, few soils actually deficient in inorganic sub- 

 stances, if properly presented to the atmosphere for decomposition. I 

 consider that the physical condition of the soil (its relation to air and 

 water) is of more importance than the introduction of the most valu- 

 able manures, although "the books" would lead us to believe that it 

 is entirely subordinate to its chemical constitution. Chemical ex- 

 periments have proved the failure of crops to proceed from a defi- 

 ciency of inorganic matter, although present in sufficient quantity in 

 the soil, yet in a state unfit for the purposes of vegetation. Many 

 and important are the chemical changes effected in this laboratory of 

 nature, when her great agents air and water are allowed sufficient 

 scope. Another advantage derived from the removal of superfluous 

 water in soils, is the increase in temperature they receive. A wet 

 soil is always cold. The heat of the sun is expended in evaporating 

 the water instead of warming the soil ; the water must be removed 

 before the soil absorbs heat. On undrained, tenacious soils this isG 



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