E X P L A I N E D BY THE MICROSCOPE. 19
natural contraâion from the evaporation and lofs of the fiuid contained in it began; PLATE
and the floccofe matter fiirank fo much fafter than the veflëls could, that though the
ends had been cut even at firft, they were foon fo altered that the veiTels flood out far Fig. 4.
beyond the Flock, and ihewed their form and feparate nature moft diiliriétly. a b
In the Ozier, taken in its feafon of quickeft growth, in Spring, the Blea affords thefe
veiTels yet more diftinflly even than the Wi l low ; but the matter is more difficultly managed
j for they are fo tender, ib foft, fo watery, that 'tis Icarce poffible to keep them
together. Fig. 5. ihews a piece of it ; in which appears this farther difcovery than Fig. 54
had been made before, that the mouths of the Blea-veiTels all open upwards.
In a piece yet farther magnified, by a combination of two of the moil powerful
objeit glafles, and with the advantage of a room conftruited plirpofely for this fervice,
a degree of light was made to penetrate the very fabftance of thefe veiTels j and the firit
appearance it exhibited was that of many Cells or Blebs, fuch as we have feen in the
Bark and Rind ; but on more obfervation, the appearance o f thefe Cells was found to be
neither equal nor regular : Nature has nothing to do with fo wild conitruftions as
feemed to /hew themfelves here : the truth was at length difcovered : thefe feeming diviiions
altered their places j and were found only to be fraall portions of a watery Sap,
which the contraflion of the part had prevented from efcaping with the reft, at the
mouths of the veffels. This appearance is given at Fig. 6. and may be a very heceffary
leffon againil hafty judgments.
A VeiTel' feparated from this Ozier Blea is ihewn by itfelf at Fig. 7. 'Tis ftrarige Fig. 7.
that the coat of veiTels fo tender ihould be fo thick in proportion to their cavity j but
this is theleait compaft of all Blea-veiTels.
C H A P , VI I .
OF THE WOOD:
A S we proceed into the more inward part of the Shoot, In whatfoever Tree, the
conilruftion becomes more difficult of obfervation: the parts are harder, and
lefs free to feparate one from the other j but with due care thefe macerations will afford,
from one kind of tree or other, pieces which will difclofe its inmoft ilrudurc.
Many muit be examined to find fuch; for it is not always in the Shoots even of the
fame fpecies thefe happy objefts may be found; the difFerent forwardnefs of the feafon,
the greater or lefs progrefs of the fap, and even the more or lefs healthy ilate of the
particular Tree, all afford variations, and render the beft fometimes inferior to thofe
naturally much below them.
F Th e