22 MODERN HIGH FARMING. 



Now we have seen that nitrogen can, though iu a very small 

 degree, be really imparted to plants and to the soil from the atmos- 

 phere; and that after having assisted, through the plant, in forming 

 the muscular tissues of the various animals, it is apt to reassume its 

 aerial character and become at liberty to form fresh combinations 

 either as ammonia or nitric acid. The actual loss, therefore, of this 

 element is comparatively small; but with the phosphorus the case is 

 a very different one, since it always maintains certain fixed combi- 

 nations, and is taken away from and irrecoverably lost to the soil in 

 immense quantities with every crop. 



Hence the same question arises here which, as we have seen, 

 arose in the case of the nitrogen, and none are more important or 

 more worthy of profound consideration : 



' ' HOW SHALL WE RESTORE TO THE GROUND THOSE ELEMENTS 

 WHICH WE YEARLY TAKE AWAY FROM IT ?" 



It will be our duty, later on, to point out the solution which 

 science has furnished to this problem, and how the remedies it pre- 

 scribes are to be employed with economy and profit. 



