PT. III. OR POISONED BY VEGETABLE GROWTH? 155 



are a plantation in this neiglibourliood, wliicli succeeded 

 immediately the felHng of an old, perhaps primo3val, 

 beech wood, on a thin staple over chalk. On that part 

 of the site of the old beech wood next the larch, a new 

 self-sown beech wood, mixed with ash and oak, has 

 sprung up, which is equally flourishing with the larch. 



In fact the soil of woods is not impoverished by The son of 



woods does 



their luxuriant growth, notwithstanding the quantity of p^jjl^^'^^"^^ 

 material taken from them by man, nor is it poisoned by 

 excretions from the roots, even of beech trees ; but, on 

 the contrary, when woods are grubbed, the soil is much 

 richer, either for the growth of trees, or of farm 

 produce, than the surrounding ground. Probably the is there 

 main cause of this is, that the roots protect the ground ^J^^^^J^J^^g 

 from aqueous denudation, and allow a greater accumu- ^^^?the'^^ 

 lation of soil, formed by disintegration and by vegetable aqueous de- 

 chemistry. At the risk of being hooted at, I w^ill, 

 however, suggest another possible cause. 



I think that there is an aerial denudation, as well as 

 an aqueous denudation, and an aerial deposit, as well as 

 an aqueous deposit ; and that woods are not only free 

 from the aerial denudation, but are favoured receptacles 

 for the aerial deposit : and that these circumstances 

 more than compensate woods even for the crops taken 

 from them by man. A part of the products of vegeta- 

 tion may be said to be stored in the bodies of animals, 

 and as carnivorous animals prey on the herbivorous, a 

 part even in carnivorous animals ; but the longest-lived 

 animals and plants die, and their hardest parts decay ; so 



