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T H E C O N S T R U C T I O N OF.TIMBER
P L A T E The Reader will be pleafed to obferve, that in this and ail the otiier figures of fcdions
ê'^en in this part of the Work, the VeiTeJs intended to be particularly Ihewn are the
only finiilied parts. The conaruaion of the reft is thrown in fliadow, that 'the eye may
not be confufed. There is more in the Pifcidla worthy of note bcûde thefe Vafa in-
. t ima j and it will be figured again with that view hereafter.
T h e exad fituation of the Vaf i intima in this Tree is always fubfervient to that of
the Vafa interiora : thofe are placed nejr the inner edge of the Bark, and the intima
keep a nearly exait dirtance between them and the Wood j three of them appear to
Fig. 2. accompany one of the interiora, as in Fig. 2.
It is not at all diflicult, after a fuccefsful maceration, to feparate fome of thefe velfels
f r om the Blea : in that ftate they appear perfcf t cylinders, with thick white coats, fiUed
with a hard red juice : and, fo far as I have been able to fee, perfectly uniform on their
Fig. furface. Some of them, thus feparated,.are fliewn at Fig. 3. It is thus alone we can
view them by the common powers and apparatus of Microfcopesj but 'tis not thus
they are fcen in their greateft beauty—To obtain that view, a piece of young Branch
o f the Pifcidia is to be cut into ihort cylinders ; one of thefe is to be fplit ; and after
j u f t fo much maceration as will loofen the parts one from another, the Wood is to be
got away. This is beft done by means of a fma!! hollow chilTel, fliaped Uke the half
o f a quill. The opening is to be made with this, and then the Wood pulled away
with a pair of fine pincers. The part where the chiiTel paffed is to be cut off and"
thrown away, and the reft prefervcd for obfervation. Many pieces ihould be treated
in this way, and chiiTels of many fizes ufed for this purpofe j for 'tis only by that
variety, and among a number of pieces, that one or two can be fdund happily cleared
F i g . 4. of the interior part. One of thefe pieces, fuccefsfully cut, is reprefented at Fig. 4.
And befide the Vafa interiora, which make a very pretty appearance in fiich an objedt,
we fee thefe intima in every view we could wiih : upon the top of the feûion we fee
their white mouths filled with a crimfon concreted juice ; and upon the fplit fides we
fcarce ever fail to fee feveral of them in their whole length j for their coats are fo
ilrong, that they very feldora tear j but ufually iland out in their places.
T h e coat of the Vas intimum has nothing of that vafcula'r ftruflure of that of the interius
: it feems one firm, folid, uniform, woody fubftance, formed to keep the precious
j u i c e it contains in perfeét fecurity. It muft not be omitted here, that this juice, in
the prefent inllance, is of a fubftance fo compaft when dry, and is fo firmly united
every way to the fides of its veiTels, that preparations once made of the parts will
never lofe their charafler. If à tranfverfe feition be cut, of but the thoufandth part of
an inch in thicknefs, and be immediately plunged in fpirit of wine, the VelTels, when
the whole is viewed in a few drops of the fame fpirit, appear as fo many rubies : and
fo firmly does their contained juice keep its place, as well as colour, that many years
fteeping in the fame fpirit docs not diffolve or feparate it. I would not venture to relate
fo ftrange a thing, but that I have many Slices now in fpirit which are unaltered in fix
years keeping. The matter of colour is fo important in this objeil, that a fécond Figureis
given with that advantage. What this indiiloluble juice is, (for neither does
water afTc<it it, otherwife than by deflroying the parts in which it is loHgcd) or what