MAN AND NATURE. 271 



beneficial to his own existence. The fui /cat SiaX- 

 Xai fjLvyVTQ)v expresses briefly what is his dealing 

 with a large class of objects in the natural world. We 

 shall touch upon some of these points hereafter ; but 

 meanwhile must speak somewhat further of the in- 

 fluence he has found means to exercise over local 

 climate a matter of deep concernment to the existence 

 and well-being of mankind. 



We say local climate ', because it is only in special 

 localities, and not generally over the globe, that this 

 influence can be brought into action. And it is well 

 worthy of note that the great agent in any such change 

 belongs to the living world, and to the domain of ve- 

 getable life one that Man can mould to his uses both 

 by propagation and destruction, yet hitherto only with 

 vague knowledge in what these uses consist. It is the 

 forest which thus actively ministers to the climatic 

 conditions of the earth ; which, extirpated by the axe 

 or restored by planting, changes both the face of na- 

 ture and the distribution and destinies of human life. 

 This simple name of Forest will hardly bring to the 

 casual reader a conception of all that it implies ; of 

 the vast extent of the earth's surface thus covered in 

 every zone, to the very confines of the arctic circle ; of 

 the various aspects and qualities of this great forest 

 mantle, and of its relation to all the moving elements 

 of the natural world. It is impossible to estimate, even 

 by loose approximation, the actual extent of surface so 

 occupied. We have given reasons for believing that 

 the earth was largely covered with wood at the time 

 when Man first became its denizen. And though in 



