294 DUE PEOPORTION OF WOODLAISTD. 



To the general truth of this sad picture there are many excep- 

 tions, even in countries of excessive cHmates. Some of these are 

 due to favorable conditions of surface, of geological structure, and 

 of the distribution of rain ; in many others, the evil consequences 

 of man's improvidence liave not yet been experienced, only be- 

 cause a sufficient time has not elapsed, since the f elhng of the 

 forest, to allow them to develop themselves. But the vengeance 

 of nature for the violation of her harmonies, though slow, is sure, 

 and the gradual deterioration of soil and climate, in such excep- 

 tional regions, is as certain to result from the destruction of the 

 woods as is any natm-al effect to follow its cause. 



Due Proportion of Woodlcmd. 



The proportion of woodland that ought to be permanently 

 maintained for its geographical and atmospheric influences varies 

 according to the character of soil, surface and climate. In coun- 

 tries with a humid sky, or moderately undulating surface and an 

 equable temperature, a small extent of forest, enough to serve as 

 a mechanical screen against the action of the wind in locahties 

 where such protection is needed, suffices. But most of the ter- 

 ritory occupied by civilized man is exposed, by the character of 

 its surface and its climate, to a physical degradation which can 

 not be averted except by devoting a large amount of soil to the 

 growth of the woods. 



From an economical point of view, the question of the due pro- 

 portion of forest is not less complicated or less important than in 

 its purely physical aspects. Of all the raw materials which nature 

 supplies for elaboration by human art, wood is undoubtedly the 

 most useful, and at the same time the most indispensable to social 

 progress.* 



and this evidence is presented with more or less detail in most of the special 

 works on the forest which I have occasion to cite. I may refer particularly to 

 HoHENSTEiN, Der Wald, 1860, as full of important facts on this subject. See 

 also Caimi, Cenni sulla Importanza del BosrM, for some statistics, not readily 

 found elsewhere, on this and other topics connected with the forest. 



* In an imaginary dialogue in the Recepte Veritable, the author, Palissy, 

 having expressed his indignation at the folly of men in destroying the woods, 

 ■his interlocutor defends the policy of felling them, by citing the example ot 

 " divers bishops, cardinals, priors, al bots, monkeries and chapters, which, by 



