120 ON THE FOOD OF PLANTS. 



destroyed the roots. At any rate, whenever I 

 have found a plant wholly killed by the appli- 

 cation of fermenting substances, I have observed 

 the roots were first destroyed. I have no doubt 

 of the correctness of Mr. Kirwan's observation, 

 that " vegetables not only require food, but 

 " that food be duly administered to them, a sur- 

 " feit being as fatal to them as absolute privation." 

 But the effect of surfeit in plants, is generally 

 the same as with animals, and discovers itself by 

 disease affecting different parts, in the manner of 

 sores and putrefying wounds, which also, as with 

 animals, are often followed by mortification and 

 death. 



If, as Mr. Kirwan states, the more solid part 

 of vegetables be submitted to dry distillation, 

 or burnt in a close vessel, it will be reduced to 

 charcoal ; and which will continue to occupy 

 almost as much space, as the vegetable itself did 

 previous to the change, and to retain the same 

 figure and the same organic disposition. It is 

 therefore very evident, that the basis of charcoal, 

 which is termed carbon, not only forms the grand 

 stamina of plants, but that it enters into the 

 composition of every part and produce of ve- 

 getables : it may hence be justly inferred, that 

 if the plant be formed by the required ele- 

 ments, taken in at the root, (and of which there 



