ON THE FOOD OF PLANTS. 139 



supply of food should be given, containing a 

 large portion of hydrogene and carbon. 



On these grounds, admitting carbonic acid 

 and carburetted hydrogene to form the food of 

 plants, we come to the following conclusions. 

 Those substances, and that mode of preparation, 

 which produce carbonic acid, and carbonaceous 

 oxydes, constitute the best food, and the best 

 state, for all plants producing grain and pulse ; 

 and surpass also, the best adapted for clovers, 

 grasses, &c., for feed and for hay ; as the quantity 

 of saccharine matter they contain, determines 

 their value, arid riot the bulk, which alone would 

 be increased by carburetted hydrogene. For 

 those plants whose seeds produce oil, such as 

 hemp, flax, rape, and all the cabbage tribe, car- 

 buretted hydrogene may be Well adapted. We 

 find those ideas corroborated by natural and 

 practical results : thus, seed-crops of grain and 

 pulse are always most healthy and prolific, on 

 lands that have been treated in that manner, 

 and left in that state, in which the roots are the 

 most completely freed from those substances 

 which produce carburetted hydrogene gas ; and 

 hemp, rape, turnips, cabbages, &c., from their 

 peculiar form of growth, are enabled to sustain 

 a large and extended surface, and can therefore 



