The Camden journal. [volume] (Camden, S.C.) 1836-1851, 1849-11-21
POPULAR ERRORS ABOUT THE
RISE AND FALL OF SAP IN TREES

! WHAT curious udliuCIilal!oil Is tl'tEl Wn'Si
supposes the sap Of tress TO fail or settle ii
the winter into the roots. Ono would have
thought that the notorious difficulty OF cran-
ming Quart of water into a pint measure
might have suggested The improbab;lIty OF
such phenomenon. For it certainly does
require a very large amount o! crednIiy to
believe that the fluids OF The trunk and head
of a tree, can by any natural force OF COM
preston. be compelled TO ente. 50 nario"
lodging at the root. =.
We shall assume the word sap 70 signify
the fluids, of whatever nature, ~ihca are
contained in the interior o. a tree. III lhc
spring the sap runs out OF The trunk Wien IL
is wounded; in the summer, autumn, and
winter i docs not, unless exceptionally,
make its appearance. But IL truth li'e sap
is ALWAYS in motion at all scasons and r"d eI
all circumstances. except in the ?rese"&s OF
intense cold. The difference is, :hal there
is great deal OF it in the spr'ns, anu much
less at at other seasons.
When tree falls to rest ar 'ae 22pT"acA
OF winter, IFS leaves have carried so I:;A-A
more 1uid than the roots have been able 10
supply, that the whole Of the intcror rs N
state of comparative dryness, and the
large portion of that sap which once was
fluid has become solid, in consequence OF The
various chemical changes 1t has undergone
Between simple evaporation on lhc one
ho' md chemical qualification on inc OH
c sap, is; in the autumn, so much d'nin-
in quantity as to be no longer uIscoV.
erauIc bv mere incisions The power that
plant may possess of resisting co!d' Is IN
proportion to the completeness OF this dry
ing process.
when the leaves have fallen of, the tree
is no longer subicclto to much loss OF llu'd by
persprallnn, nor 10 extensive chemical chah-
yes by assimilation. But the absorbing pow
er Of the roots is not arrested; they on the
contrary 90 on sucking fluid from the SOIL
and driving it upwards into the system
The effect of this is, that after some months
of such action, loss' of fluid which the tree
has sustained in autumn bv It's leaves, is made
good. and The whole p liant Is dIslendcd win
wa,cry particles. This is most wise pro-
vision III order to insure abundant tood 10
new born leaves and branches when warmth
aud light stimulate them into growth.
During all the winter period the sap aP-
pears to be at rest, for The rcfillIng process is
a very gradual one. But M. Blot many
years ago proved by an ingenious apparatus
hat the rate oImo,ion of the sap may DC
measured at all seasons, and nc ascertaiIIcd
it to be in state of considerable influence
upon tho direction in which the sap moves.
In mild weather The sap was constantly r.
sing. but when fros, was cxPcr'enced' INC
sap flowed back agaIn-a phenomenon
which he referred to the contracting power
OF cold on the vessel OF the lrui.i a"I branch
cs, the effect Of which was 10 iorce Inc sap
downwards INTO the roots lying IN warm
er meGlum; thcn, again, when the l'ost
reached the roots themselves and began ac'
ting on them. The sap was forced back Inio
the trunk: bu, as soon as thaW came on
and the ground recovered lis heal, the f'o'S
out of which part Ut the sap tan pee''
forced Upwards. we're again fl!icd ~ thc
fluids above them, and the sap was l"fced
to fail. A large poplar tree IN the lalicr
state. having been cut across at the ground
line. the surface OF tho stump was !n!ii'u 10
be dry, tut the end OF the lrnnk 'ls"A d'prca
with sap. Sap then is always III m"'"n'
and if II ever settles 10 The root IN Visible
manner, that is owing to temporary CAUSES
the removal of which. causes lis instant re-
ascent.
As to the idea that the b!ecding .! I'e"
begins first at the root, and III connection
with this suppnSinn. lha. what Is called 'ii@
rise oflhc sap is tie cause OF the cNpii'S'n
o buds and leaves and braEchc'' mt"ri-
can well be more destitute oI any rGaI !"nI.-
daion. lfin the spring, when tic hn.a af~
lust swelling. tree Is CHI across al ''e
ground Inc, no bleeding Will iakH pace
neither will he sap ilow for some distance
upwards, bat among the branches inc D'cHH-
,nc will be found to have c"rn'ncnceh. bis
was observed some years ag" nE AlF.
Thompson, at that tlrnc the Duke OF Fort
lands gardner. who thought nc had hSc"'-
cred that the sap of trees dcSccndS IL TIC
spring, instead of ascending; strange spec
ulaiIniI cinuy! IL llillSl DC E"iiIS"|'. .''c
fact is tia, the sap is driven into accelerated
motion first at the cxrcmllIes OF tree. &c
cause i, is there that light and warmth tFsi
tell upon tc cxci,ablc buds. .hc mo'ncn!
the buds arc excited thcY begin to anrE sap !
from the part they are IN contact; - supply
the waste soproduccd, the adIaccn''S2p pnsH
cs upwards; as the expansion Of tic leaves
proceeds. tho demand upon the sap near
them becomes greater; quicker motion %ll!I
is necessary on the par: oi the sap I" maze
good the loss; and thus from above Gown
ward is that pcrccpiiblc flow OF the il,'"!5 OF
trees, which we call bleeding. effected.
The well known fact OF trees Spr"u;InG
in ,hc spring. although fcIIcd Ill the anlo'nn,
proves that tho sap had not At that ln'" QUIT
icJ ,h, ,ruuI; 10 take refuge IN the roots. |