94 
WOOD AND BARK OP TREES. 
Chemical 
trials too soon, 
Specimens of 
bark. 
I could mention) proved it. If Mr. K., therefore, stops up the 
usual current, it may force itself into the bark to find a pas- 
sage. But this does not teach us what are the directions of its 
sap-vessels ! This is the reason of my disliking all these ex- 
periments (at one time so much the fashion) and which, I am 
firmly persuaded, is the grand cause of the mistakes made in 
phytology, and the reason why so little is known. A wrong 
road was marked out, or it was taken too early, before a foun- 
dation was laid. I am only a dissector ; I pretend to nothing 
but delivering faithfully what I see, without exaggeration. If 
this matter was to be decided by argument or general know- 
ledge, I should never attempt to contradict a gentleman of 
Mr. Knight’s understanding and abilities ; but, after the quantities 
of dissections I have made (and I have many hundred barks 
drawn by me, besides the twenty I have taken to pieces) I 
must be well acquainted with that part, and there certainly is 
not a single sap-vessel to be found in it, except the nou- 
rishing vessels passing in their separate cylinders to the leaves. 
The specimens I have given on figs. 5 and 6 , will serve as a 
pretty good example of barks in general, as they strongly re- 
semble each other. 
I must apologize for some repetitions in this letter, having 
already givtn a description of each separate part. Now that 
I come to ally those parts to each other , to cement the whole, 
and to shew in what manner they prove the truth of each indi- 
vidual observation, it will not be always in my power to avoid 
shewing what has already been read. But I will do it as much 
as the explaining simply and plainly will permit. 
Your obliged Servant, 
AGNES IBBETSON. 
Cowley Cot f 
2 5th Jan. 1813. 
, .... .-V ’ ■’ 
