T H E C O N S T R U C T I O N OF TIMBER
P L A T E Thcfe lie immediately »Ithin, or under one another: and in, among, and between
_ Ihefe are difpofed the Veflels, which feed the whole; and fome of which contain the
juices, that give the Tree its peculiar qualities, and virtues.
Thefe Veffels are of five kinds :
1 . The EXTERIOR
2 . The INTERIOR [ JUICE-VESSELS.
3 . The INTIMATE
4 . The SAP-VESSELS,
5 . T h e CORONAL.
O f thefe, the firft are placed between the Rind and Bark;
The fécond, in the fubftance of the Barkj
The third, in the fubftance of the Blea j
The fourth, in the fubftance of the Wood j
The fifth, in the Corona, or Circle of Propagation.
Befides thefe greater Veflels, the feveral parts themfelves are vafcular ¡ h u t their Tubes
are of another kind ; and will be confidered when we examine the conftrudUon of thofe
feveral parts. Other Glafl-es wi l l be required.for this : they fcatce appear in the prefent
V i e w ; which is limited folely to the arrangement of the conftitucnt parts together.
The tree in which thcfe feveral circles lie in the happieft way fer obfcrvation, is the
Scarlet Oak of America. If a flice be cut from a two years and a half Shoot of this
tree, in May ; the parts and veflils j uft enumerated will be feen as they are reprefented in
P L A T E Plate III; and this with great diftindnefs and precifion. Where this tree is not at hand,
fcch a flice of the common Englifti O a k will very well fupply its place, the parts lying
very nearly in the fame manner.
a a reprefents the Rind, dry, and very thin.
b b, the exterior Jaice-vefl-els. Thefe are placed in round dufters , they are woody ,
and contain a thin, whitifli, watery juice, of no tafte.
c i, theBark. This confifts of a multitude of filmy bladders, ranged in circles, one behind
another : they are elliptic, thin, and brownilh ; and they hold alfo a watery juice.
They are connefted together, and arife in thefe circles one behind another.
d i, the interior Juice-vefl-els. Thefe are arranged in oval clnfters, avery coirCderable
number of them together. They are of many times the diameter o f the preceding: their
coats are woody ; and they contain a thick, gummy, brown juice, of an anftere, ftyptic
tafte. This gives the virtue to the Oak Bark, as an aftringent ; and its quality, fo ufeful
in tanning animal hides.
s reprefents