226 SCIENTIFIC AGRICULTURE. 



the execution of all her laws, and that she does nothing by 

 accident. And whenever we find an apparent exception to 

 this principle, it is evident that our knowledge is deficient or 

 our conclusions erroneous. 



Hence, although plants may be made to maintain a transi- 

 tory and sickly existence without all the usual elements, and 

 to absorb both by their leaves and roots, substances unneces- 

 sary and pernicious to their growth, still from the uniformity 

 of the elements and their proportions, as shown by analysis of 

 the plants and the soils in which they thrive best, we are com- 

 pelled to conclude, that each and all of these elements, are in- 

 dispensible to their healthy growth and maturity. And who- 

 ever practically disregards this principle, and hangs his hope 

 of success on some contingent circumstance, must correct his 

 error at his own cost. 



