34 T H E CO-NS T RUC T ION OF TIMBER
P L A T E thefe VcSels, Jong iLook about in water, that the outer membrane has feparated itfelf
^ ^ ^ • like the bull of an almoud in blanching 5 and in this .ftatc we not only fee that there
is fuch a membrane, or probably a number of fuch membranes, but alfo that they
F i g . 4. are vafcular, as at Fig. 4.
5' A fpllt and hollowed piece of the Willow Oak is reprefented at Fig. 5. in which
t h e thick coats of thefe VelTels render them very confpicuous.
T h e f e Veflels, which are, in nature, cifterns of Sap for the feeding th e g r owt h of the
w h o l e T r e e ; and f rom which it bleeds fo freel y in the Spring and at Midfummer i are
f o large that they are capable of being filled with coloured wax, in the manner of the
veflels in anatomical injedtions j and this way they afford f o pleafing objefts for the
M i c r o f c o p e , and give fuch excellent opportunities of tracing thei r courfe and ftrufture,
t h a t it would be invidious to conceal the method f r o m the curious Reader,
A view of pieces of the Oak, thus treated, and of the effefl it has upon their
Veflels, is given in the additional Plat e XIV.
T h e Method of filling the VelTels is this :
A great many pieces of the Scarlet and other Oaks are to be taken off In Spring;
t h e y mull: be cut into pieces of about two inches length, and immediately from the
c u t t i n g they muf t drop into fome warm rain water : in this they are t o ftand four and
t w e n t y hours; and then be boiled a little. When taken out they are to be tied on
f i r i n g s , and h u n g up in a place wher e the air pafles freely, but the fun dees not ihine.
W h e n they are perfeft l y dry, a large quantity of green wax, fuch as is ufed for the
feals of law deeds, is t o be gently mel ted in an earthen pipkin fet i n water, the water
t o be heated and kept boling. As foon as the w a x runs, the Sticks are to be put in ;
a n d they are f r equent l y to be ftirred about. They muf t be kept in this ftate about an
h o u r , and then the pipkin is to be taken out of the water, and fet upon a naked
fire; where it is to be kept , with the wax boiling, for two or three hours; freili
f u p p l i e s of the fame green wax being added from time to time.
A f t e r this it is to be taken from the fire, and the Sticks immediately taken out with
a pair of tongs. When they are cold, the rough wax about the m is to be broken off.
B o t h ends of each Stick are to be cut off half an inch long, and thrown awayj and
t h e middl e pieces faved. Thefe are then to be cut into fmaUer lengths, fmoothed at
tlie ends with a fine chilTel, and many of them fplit in various thicknefles.
T h u s are obtained preparations, not only of great ufe, but of a wonder ful beauty.
M a n y Trees afford h andfor a e objefts as well as the O a k j and in fome, where the Sap
Vcffels are few, large, and diftinft, the fplit pieces refemble ftriped fatins, in a way
f c a r c e to be credited. It is in fuch that the outer coats of thefe Veffels are mof t hapi
pi l y of all to be examined.
C H A P .
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