l'2i ON THE FOOD OF PLANTS. 



** most valuable and most efficient. Dung 

 " which has fermented, so as to become a mere 

 " soft cohesive mass, has generally lost from one- 

 " third to one-half of its most useful constituent 

 " elements. It evidently should be applied as 

 " soon as fermentation begins, that it may exert 

 " its full action upon the plant, and lose none 

 " of its nutritive powers.'* 



Again, " All green succulent plants con- 

 " tain saccharine or mucilaginous matter, with 

 " woody fibre, and readily ferment. They can- 

 " not, therefore, if intended for manure, be used 

 " too soon after their death." 



A reference to the principles of chemistry, most 

 certainly induces me to form conclusions very 

 different to Sir Humphry : in his explanations 

 of chemical principles, and their combinations, 

 no doubt he is clear and correct ; but many of 

 his applications of those principles, and his in- 

 ferences, appear to me to be superfcial, hypo- 

 thetical, and fallacious : and this most probably 

 arises from a want of practical knowledge and 

 observation. His opinions seem to be grounded 

 on the belief^ that in the production and appli- 

 cation of food for plants, quantity is the *^rand 

 desideratum. He appears to have no notion 

 that the health and condition of plants determine 



