48 WASTE AND RECONSTRUCTION. 



that, many as are the agents at work and complicated as are 

 their modes of action, yet, on the whole, they may be con- 

 veniently arranged into two grand categories namely, the 

 powers of waste and degradation from without, and the 

 powers of reconstruction and upheaval from within. As 

 surely as the meteoric and aqueous disintegrate and level, 

 so surely does the igneous reconstruct and upheave ; as 

 the chemical and vital dissolve and destroy in one area, so 

 they recombine and build up in another. There is nothing 

 so harmonious as this incessant round of mutation, nothing 

 so marvellous as the variety it produces, and yet nothing 

 so certain as the unity of design by which the whole is 

 combined into one intelligible system. Strange as it may 

 seem, even the comfort and development^ of man is indis- 

 solubly bound up with this system of vicissitude. It is 

 not the rugged and flinty hill-side that yields him his sus- 

 tenance. He cannot build his cities on its peaks or plough 

 its precipices. And yet these hills are the great store- 

 houses of future fertility. The rains, the frosts, the streams, 

 and the rivers are perpetually carrying down from their 

 heights the materials to form the fertile valleys washing 

 out from the old crystalline rocks the inorganic elements 

 indispensable to vegetable luxuriance. And on these moun- 

 tain-derived plains man has hitherto settled in communi- 

 ties and built his cities. The plains of the Old World, 

 the historic fulfilments of the past China, Hindoostan, 

 Mesopotamia and Egypt were borne down from the 

 mountains of Asia and Africa ; just as the prairies, the 

 llanos, and pampas of the New World, the hopes of the 

 advancing future, are the gifts of the Andes and the Eocky 

 Cordilleras. How marvellous this system of interdepend- 

 ence between the organic and inorganic between the 

 mechanical processes of nature and the social development 

 of man ! How admirable this system of unceasing rejuven- 



