276 PHYSIOLOGY OF TREES. 



allusion be made to the chemical agency attri- 

 buted to plants ; their susceptibility of electric 

 action ; the different vessels discovered in the 

 wood and bark ; their forms, uses in the system, 

 &c. &c. ; all which discoveries being far beyond 

 the reach of practical penetration, and proveable 

 only by the exercise of chemical and physical 

 philosophy, need neither be scrutinized nor re- 

 iterated here. 



Those living authors, whose opinions I have 

 so freely canvassed, and with whose ideas of 

 vegetable life and processes I have been com- 

 pelled to differ, I can only take the liberty of 

 referring to the arguments by which I have 

 endeavoured to substantiate my allegations, for 

 justification in dissenting from such high autho- 

 rities. But to their candid consideration I re- 

 spectfully submit my statements, trusting that 

 what T have advanced on the subject may at 

 least lead to clearer views of physiology, and be 

 accepted as a mite thrown to the general stock 

 of botanical knowledge. 



