Lewisburg chronicle. [volume] (Lewisburg, Pa.) 1850-1859, 1850-05-29

discoverable by mere incisions. The
power that plant may possess Of resiss.
ing cold is in proportion to the complete.
ness Of this drying process.
When the leaves have fallen of, the
tree IS no longer subject to much loss Of
fluid by perspiration, nor to extensive
chemical changes by assimilation. But
the absorbing power Of the roots, is not
arrested they. on the contrary, 60 on
sucking fluid from the soil, and driving ii
upwards into the system. The effect OF
this is that after some months Of such an
action, tha: loss of fluid which the tree has
sustained in autumn by its leaves is made
good, and the whole plant is distended
with watery PARTICLES. This is a most
wise provision in order 10 insure abundant
food to the new born leaves and branches,
when warmth and !igh, stimulate them in
10 growth.
During all the winter period the sap ap.
pears 10 be at rest, for the re.filling process
is very gradual one. But NJ. Blot many
years ago proved BY an ingenious appara-
tus, that the rate of motion OF the sap may
be measured q, all seasons. and he asser.
tanned it to lie in state of considerable
activity ia md-winier. Among other
things. '.e found that frost had considerable
Influence upon the direction in which the
sap moves In mild weather the sap is
constantly rising, but when frost was ex.
porienccd the sap flowed back again-a
, iht nomenon which he referred 10 the coll
tracing power Of cold On the vessel ol
, the trunk aud branches. the effect OF which
vas to force the sap downwards into the
roots, lying in warmer medium then,
egain, when the frost reached the roots
themselves ard began acting on them. tie
sap was forced hack into the trunk bu,
as soon as thaw came and the ground
recovered its heat, the roots out Of which
apart Of the sap had been forced upwards.
were again filled by the fluids above them.
and The sap was forced to fall. A large
poplar tree in The latter state, having been
Gu, across a, the ground line, the surface
Of the stump was found TO be dry, but the
end OF The trunk itself driPped with sap.
Sap, Then. is always in motion, and il il
ever settles TO the roo, in visible manner.
that is owing 10 temporary causes, the re-
moval Of which causes its instant re ascent.
As 10 the idea lha, the bleeding Of tree
begins frs. Il, the root, and in connection
with this suPposltion, that what is called
the rise Of The sap is the cause Of the ex-
pansiou Of buds aud leaves and branches,
: nothing can sell be more destitute Of any
real io"ndalion. II in the spring, when
lie buds are Just swelling, tree is Gu,
across AT ,le ground line no bleeding will
iake pace, neither ill the sap flow for
some distance up~ ards. but among the
branches The bleeding will be found 10
have commenced. This WIS observed
some years ago by Mr. Thompson. a, ,ha,
lime the Duke Of Por.land's gardener, who
though, he had discovered that the sap OF
trees desctnds in the spring, instead Of as
cending strange speculation enough it
must be confessed. The fact is. that The
sap is driven into accelerated motion FIRST
al the eylrcmites OF a tree because il is
there iha, gh. and warmth frs, tell upon
the eyci'able buds. The moment the buds
are excited lhey begin 10 suck sap from
the parts with which they are in contac,
to supply the waste so produced, the ada.
4 cent sap pushes upwards as the expan.
5 sion Of the leaves proceeds, the demand up
on the sap near them becomes greater n
quicker motion still is necessary on the
par, OF the sap 10 make good the loss /; and
. thus from above downward is that percep,i-
2 ble flow Of the fluids Of trees, which We
n call bleeding, effected.
The we'll known fact Of trees sprou,ng
, in The sp.ing, although feled in the au.
tumn. proves lha, the sap had no, a, that
;ime quilted The trunk to lake refuge in the
roots. Such a common occurance should
Pc, people on :heir guard against falling
into The vulgar errors on this subject.
--~----~-->~.~->~--~~~>--~ -~------~----
From the American Agricultur;st.