ON SOIL. 43 



more compact soils ; and, clinging like ivy romid the 

 porous surfaces of their retreats, extract therefrom a 

 species of food, more nourishing than that obtained 

 by them under any other circumstances whatever. 



One of the principal causes of grapes not ripening 

 well on open walls in this country, is the great depth 

 of 7iiould in which the roots of vines are suffered to 

 run, which, enticing them to penetrate in search of 

 food below the influence of the sun's rays, supplies 

 them with too great a quantity of moisture; vegeta- 

 tion is thereby carried on till late in the summer, in 

 consequence of which, the ripening process does not 

 commence till the declination of the sun becomes too 

 rapid to afford a sufliciency of solar heat to perfect 

 the fruit. 



To prevent this, the sub-soil should be composed 

 of dry materials. It is almost impossible, indeed, to 

 make a vhie border of materials that shall be too dry 

 or porous. It is not mere earth that the roots require 

 to come in contact with, to induce growth and exten- 

 tion, but air also, which is as necessary to them as to 

 the leaves and branches. The excrementitious mat- 

 ter discharged from the roots of a vine is very great ; 

 and if this be given out in a soil that is close and 

 adhesive, and through which the action of the solar 

 rays is feeble, the air in the neighborhood of the roots 

 quickly becomes deleterious, and a languid and 

 diseased vegetation immediately follows. But if the 

 roots grow in a soil composed of dry materials, mixed 

 together in such a manner as to possess a series of 

 cavities and interstices, into which the sim's rays can 

 enter with freedom, and there exert their full power, 

 the air in which the roots perform their functions be- 

 comes warmed and purified, they absorb tlieir food in 

 a medium which dissipates their secretions, and a 

 healthy and vigorous vegetation is the never-failing 

 consequence. 



The roots of every plant have a particular tempera- 

 ture in which they thrive best; and that which those 

 of the vine delight in most is generated in a greater 



