THE ROOTS OF GRAPE VINES. 185 



Rafters and sashbars reduce the quantity of light that 

 the glass admits, and thus operate injuriously ; they 

 are, however, necessary evils, but the fewer there are 

 in number within a given space, and the less surface 

 each occupies, the better. But to plant a vine, the 

 main stem or branch of which will become one of its 

 grand receptacles of nourishing matter, in a situation 

 where the direct rays of the sun can never reach it, is 

 certainly one of the most absurd and contradictory 

 things imaginable. The proper situation, without 

 doubt, is under the centre of a light : the main stem 

 and all the branches, and, of course, the fruit also, will 

 then enjoy the full power of the sun. 



The bed of materials being made and enclosed, and 

 the vines planted, a brief review may now be taken of 

 the conditions by which the roots are surrounded. 



Here, then, is a mass of materials, the mechanical 

 texture and arrangements of which constitute the very 

 delight of the vine. 



The innumerable cavities and interstices, and the 

 extraordinary extent of surface for the roots to tra- 

 verse which such a mass possesses when put compactly 

 together, offer to the roots of the vines planted in it 

 such facilities of growth, and the substances them- 

 selves such means of nourishment and support, as can- 

 not be obtained from an hundred times its bulk of 

 mere soil. All the substances, except the bones, pos- 

 sess in common the highest powers of absorption. The 

 porosity of charcoal is such, that its cells occupy more 

 than one half of its cubical contents. The beneficial 

 effects of it, therefore, as an absorbent, and a retainer 

 of moisture, render it invaluable as a component. 

 Whereve" charcoal is placed in situations that exclude 

 the atmospheric air, dryness can never enter, tt is 

 said to be under such circumstances indestructible ; 

 but that is not the case when the roots of vines fasten 



