of the heart wood of trees. 143 
which I have made, lead me to think it probable, that both 
the alburnum and heart wood become improved in quality 
under such circumstances ; but I am not at present in pos- 
session of such facts as can enable me to give any decisive 
opinion. 
I am, my dear Sir, with great regard, 
sincerely yours, 
T. A. Knight. 
Downton, Dec. 24th, 1817. 
