268 APPENDIX TO PART I. 



water, together with the alkaline and earthy ingredients 

 which are derived from the soil, nor am I aware of any 

 proof that they may not likewise be assimilated when so 

 introduced. 



'* The theory of M. Decandolle, therefore, is not affected 

 by the above experiments, but must rest on its own merits, 

 and continue to afford a subject for inquiry to the scientific 

 agriculturist." 



Practical Inferences. From Dr. Dauheny^s Lectures on 

 Agriculture, delivered at Oxford, 1841. 



'^The first inference that may be drawn, relates to the 

 utility of diligent and frequent tillage, in order to favor the 

 disintegration of the soil, and the free admission to it of 

 oxygen and of water. 



"Unless the former take place, no fresh alkali can be 

 extracted from the subjacent rock by the action of water 

 upon it ; unless the latter be brought about in a sufficient 

 degree, the humus excluded from air cannot undergo that 

 process of eremacausis, or gradual combustion, on which 

 its influence upon the nutrition of plants has already been 

 shown to depend. 



"Hence, in ancient times, the importance attached to 

 those operations which had this object for their aim, — 



" ' Quid est agrum bene colere ? ' asked Cato. ' Bene arare. Quid 

 secundum? Arare. Quid tertium ? Stercorare.* 



Thus ploughing was regarded the most important process 

 in agriculture, after which, though at a long interval, came 

 manuring. 



" The design, therefore, of the agriculturist is, to reduce 

 the soil to that loose and crumbling condition, in which it 

 becomes entirely pervious to air and moisture, imparting to 

 it the quality which the ancients denominated putre. 



" * Et cui putre solum, (namque hoc imitamur arando,) 

 Optima frumentis.' 



"Hence the superiority of spade husbandry over the 

 plough, if the expense of the labor be not taken into the 

 account ; hence the fertility of the small farms of the ancient 

 Romans, notwithstanding their rude methods and their 

 deficiency of skill ; hence the fine condition of those tracts 

 of land, which are subjected to the unremitting manual ex- 

 ertions of societies of men like the Trappists, whose mis- 



