Vermont farmer. [volume] (Newport, Orleans County, Vt.) 1870-1877, 1875-04-16
Principles Of Horticulture.
X. SAP.

260. The fluid matter which is absorbed
either from the earth or from the air is
called sap.
26l. When it first enters plant, it con-
sists Of water holding certain principles, es.
pecially carbouic acid, in solution.
262. These principles chiefly consist OF
animal Or vegetable matter in state Of de.
composition, and are energetic in proportion
to their solubility, or tendency to form car
bonic acid by combining with the oxygen of
the air.
263. Sap soon afterwards acquires the
nature Of mucilage or sugar. and subsequent :
ly becomes still further altered by the ad-
mixture Of such soluble matter as it receives
in passing in its route through the alburnum
Of newly formed woody issue.
264. When it reaches the vicinity of the
leaves, il is attracted into them, and there,
having been exposed to light and air, is con-
verted iRto the secretions peculiar to the
species.
265. 1t finally, in its altered state, SINKS
down the bark, whence it is given off lat
orally by the medullary rays, and is distrib-
uted through the system.
266. No solid matter whatever can be
taken up by the roots; for this reason,
metals, which in the state of OK ides are poi
sonous, are perfectly harmless in their me-
tallic state, as mercury; and this is, no
doubt, the cause why liquid manure, which
contains all the soluble parts Of manure in a
fluid state, acts with so much more energy
than stimulating substance in a solid state.
267. The cause of the motion Of the sap
is the attraction of the leaf.buds and leaves.
26S. The leaf-buds, called into growth by
the combined action of the increasing TEN.
perature and light of spring, decompose their
carbonic acid, and attract fluid from the It's
sue Immediately below them the space SO
caused is filed up by fluid again attracted
from below, and thus a motion gradually
takes place in the sap from one extremity to
| the other.
269. Consequently, the motion Of the sap
takes place first in the branches and last in
the roots
go. For this reason, branch of plant
subjected to a high temperature in winter
will grow while its stem is exposed to very
low temperature.
27l. But growth under such circumstan-
ces will not be long maintained, unless the
roots are secured from the reach of frost /;
for if frozen they cannot act, and will conse-
quently be unable to replace the sap of
which the stem is emptied by the attraction
Of the buds converted into branches, and by
the perspiration Of the leaves.
272. Whatever tends to inspissate the
sap, such as dry and heated atmosphere
or an interruption OF its rapid flow, or a
great decomposition of carbonic acid by full
exposure to light, has the property of caus-
ing excessive vigor to be diminished, and
fower-buds to be produced.
273. While, on the other hand, whatever
tends to dilute sap, such as q damp atmos-
phere, free aud uninterrupted circulation,
or great accumulation of oxygen in conse-
quence Of the imperfect decomposition Of
carbonic acid, has the property of causing
excessively rapid growth, aud an exclusive
production Of leaf-buds.
274. Inspssated or accumulated sap is,
therefore, great cause of fertility.
275 And thin fluid, not being elaborated,
is great cause Of sterility.
276. The conversion of sap into different
kinds Of secretion is effected by the COM
bined action Of Air, Light, and Tempera-
tuTe.