So VEGETABLE STRUCTURE.' 
continually difcbarges Its watery part into the Cells between them ; and 
perhaps there are other fources of a fimple fluid which fill them. Cer- 
tainly the great quantity of water imbibed and perfpired by Plants, is princi- 
pally lodged in thefe Cells of the Blea. 
Having thus far examined the general ftrudlure of the Blea, we are 
to proceed in our fearch, by taking off a thin piece from its outermofl; part 
length wife. Such thin pieces are eafily obtained from the thicknefs of the 
inner Rind, becaufe it Is compofed of feparate Plates or Couches ; but in 
this we muff obtain by art what offers itfelf fo eafily there. To this end, 
having feparated the two Rinds clean from a piece of the Flowering Stalk 
of Hellebore, we are to raife a thin piece of the Blea with the point of the 
Lancet-fciffirs ; and taking hold of it with fine Plyers, to tear it off, length- 
wife, and upward, from the reft. The thinneft part of this is to be work- 
ed well on its inner furface in water, with a camel’s hair pencil j and with 
due care we may walh away all but one feries of Veft'cls and their Mem- 
branes. The inner furface will be irregular, but the thicknefs will be no 
more than that of one Couch of the Rind. 
We thus fee the Courfe of the Veflels, riling In a curved manner, and 
conneded together by very frequent arched ones, placed, as the crofs-bars, 
in the two Rinds ; but with this great difference, that here what appear 
as arched parts in this view, when we fee the whole more enlarged, are 
found to be really portions of the Veflels themfelves, not feparate Veflels 
arifing from them, as in the Rinds. 
A PIECE of the outer furface of the Blea, with the exterior fide upper- 
moft, appears to the Microfeope with a confiderable power of magnifying, 
as at Fig. 51, Plate V. What ftrikes the eye firft in this view is, that 
there appear a kind of interftices at the places where the Veffels pafs over 
one another: but this Is the natural refult of their form. Thefe Veflels do 
not run up ftralt, as thofe of the Rind, but bend backward and forward, 
repeating from fpace to fpace, the form of the letter S. Any two of them 
which run in this form, in an oppofite diredion, will crofs one another at 
the two places where the bend is made, and confequently there will be 
formed between them two elliptical figures, or one fuch figure by each half 
of the double S. This cannot be feen diftindly in a piece of the fubftance 
managed as at Fig. 51, becaufe the Veffels will have been forced a little 
from their original courfe, by the violence ufed in preparing the piece j but 
even in that fragment which is engraved exadly from Nature, fomething 
of this general courfe may be feen, and the whole will be underftood dif- 
fmdly 
