140 ON THE FOOD OF PLANTS. 



appropriate a large portion of carburetted hy- 

 drogene without injury. 



A due attention to these particulars will ex- 

 plain the want of accordance in the opinions of 

 Sir Humphry Davy, with many of the operations 

 that are most successfully practised by many 

 eminent farmers. Indeed, if the food of plants 

 was wasted, by exposure to the atmosphere ; 

 ploughing and stirring up the soil must occasion 

 waste and sterility ; and the same must be the 

 case with turning over, and exposing masses of 

 dung; but, observing practitioners well know 

 that those processes are followed by additional 

 prolificacy. 



That class, among the cultivators of plants, 

 who, of all others, pay the most attention to their 

 health, and proper condition for fructification, 

 is, perhaps, the florists ; and the most eminent 

 amongst those, make it their practice to mix and 

 turn over their compost at short intervals, so 

 that every part may be exposed to the influence 

 of the sun, air, and light, for at least twelve 

 months before they use it. 



The fact is, I believe, that whether carbon 

 and oxygene combined, as carbonic acid, be the 

 best state of preparation for the consumption 

 of plants, or not ; carbon and oxygene form the 



