14 



INTRODUCTORY REMARKS. 



a paradox of the most extravagant kind. If such 

 readers, however, will be at the trouble to give a 

 little attention to the following suggestions, the fact 

 may appear to them much less unaccountable. 



Trees draw their nourishment from a much great- 

 er depth than any of the grasses, roots, or different 

 kinds of grain raised by the agriculturist. Most of 

 the latter derive the whole of their subsistence from 

 the part of the soil that lies within a few inches of 

 the surface; but the former, from the superior 

 strength and magnitude of their roots, are enabled 

 to penetrate much farther, and extract food from 

 the very rock which forms the substratum of a great 

 proportion both of our cultivated and uncultivated 

 grounds. This, though it does not account for 

 lands being positively enriched by wood, makes it, 

 at the same time, far less surprising that trees should 

 grow to a large size, and yet not exhaust the upper 

 part of the soil in so great a degree as most of the 

 crops cultivated by the farmer. 



There is another circumstance which gives ground 

 in wood a great advantage over that in tillage, 

 which is, that the leaves of the trees are suffered to 

 decay and rot where they fall, and, by this means, 

 an annual addition is made to the depth of the ve- 

 getable mould. Now, the leaves of a tree may be 



