WITH AGRICULTURE AND PLANTING. 485 



powers in various ways. The atmosphere is perpetually 

 modifying it ; rivers, waves, and winds, act here and 

 there upon its surface, and alter its external form ; wa- 

 ter introduces into it the substances which it holds in so- 

 lution. The different constituent parts of soil act upon 

 each other chemically, and in this manner new decompo- 

 sitions and mixtures are produced ; and this chemical 

 change is increased by the action of vegetables, as well 

 as of bodies deriving their origin from both organic 

 kingdoms. 



From what has been said of the relations existing be- 

 tween the masses of which the solid crust of the globe is 

 composed, and the loose earth or soil by which it is co- 

 vered, it appears evident enough (Hausmann concludes) 

 that they have great influence over its formation and na- 

 ture, and therefore upon the more perfect vegetables, 

 and especially those which are the objects of cultiva- 

 tion ; and that although the fertility of the soil is much 

 increased by these vegetables themselves, yet the first 

 foundation of their vigour is derived from the disinte- 

 gration and decomposition of rocks. If this be correct, 

 the constitution of the solid crust of the earth has a 

 much more extended influence. For, by preparing a 

 habitation for the greater and most important parts of 

 plants, it also exerts a high degree of influence upon the 

 animals which derive their sustenance from them, and, at 

 the same time, affords the means of subsistence to man *. 



* Those who feel disposed to examine the connection of Geology 

 and Agriculture, will find many additional details and views given in 

 Hausmann's work, of which the above may be considered in some de- 

 gree as a condensed view. 



