LETTER IX. 



91 



with the utmost precision determine, what were the 

 characters of the seasons 500 or 1500 years ago. 



23. But, allowing that no such molecular change 

 takes place in the woody matter, nor any farther 

 increase of growth, the sap continues year by year to 

 move through it ; and this movement is a vital action, 

 and due to vital agency : True. And is not this a 

 proof that the old wood still continues to be possessed 

 of vitality ? In my next letter we shall consider 

 whether it be or no. — Meanwhile, believe me, &c. 



