The Vermont watchman. [volume] (Montpelier, Vt.) 1883-1911, 1885-04-22

mineral matters in solution potash,
phosphoric acid, lime, nitric acid, etc).
When the tree opens its leaves this
crude sap is drawn into them, and is
there exposed to the atmosphere and
sunlight. The leaves take up carbonic
acid and probably other gases, and
under the chemical action of light these,
aided by the mineral matter in the sap,
are combined to form carbohydrates
Starch, sugar, gum, wooD, hydro
carbons Qat-oils, wakes, resins, bal
sans, essential oils), together with the
various other organic matters, more or
less peculiar to each species. Possibly,
even probably, these combinations are
not all completed in the leaves, but the
materials are brought together there,
though their union, in the various
forms, may be partially effected else
where. After the leaves have given to
the sap these atmospheric elements,
and their combinations begin, consid
cradle share of the new-formed mate
rial is used in the growth of the leaves
themselves, and in the shoots, or young
branches. But a part is sent down
ward, between the wood and the bark,
even to the most distant extremities of
the roots, to make a new layer of wood
all the way. AT this time the carb-
| hydrates must exist dissolved in the
water of the sap. AS the various sugars
and gums are soluble, while starch and
woody fibre are insoluble, we have
right to infer that the new sap holds its
carbohydrates first as sugar and gum,
and that the change into the less soluble
forms only takes place (perhaps under
the influence of substances stored up in
the previous years layer slowly, as it
flows along. There is also a lateral
(sideway) movement of the sap, from
the outside towards the center of the
trunk, in woody plants. AS we know
that the heart-wood" grows harder
and heavier and, when burned, pro-
duces more ashes than the new wood,
we may infer that the sap, after depos-
iting its sugar as wood and gum in the
outer layer, works inward, and leaves
some of its potash, lime, ETC., in the
older layers. 1t also takes inward other
substances found in the heart-wood.
But still another thing seems evident,
namely, that, in some species at least,
all of the sugar is not changed to woody
matter during the first season. Part
remains, either as sugar or starch, in
the newly-formed wood, and to a less
extent in the successive layers beneath.
If it remains as sugar, it may be in So
luton in the moisture of the wood. But
a part or all Of it may be deposited as
starch Gin some cases as gum until the
next spring, when it may resume the
sugar form, the two being of the same
composition, except in the matter of
one, two or three atoms, more or less. of
water.
When spring comes again the deeper
roots, below frost, send up the watery
sap, and this takes the sugar into solu-
ton again, or dilutes the solution al
ready there. The fact that, as Mr..
Wheeler says, in the spring the main
bulk of the sap lies within twelve feet
of the ground" favors the view that
the water which takes up the sugar,
and constitutes with it the sugar-mak-
er's :" sap" comes from the roots be-
The potash and lime brought up in the
root-water at the same time unite with
, acids in the sap-wood, forming the
entire" which we find in the syrup
after boiling.
Besides the sap in the tree, there is
also considerable quantity of air, of
carbonic acid gas, and perhaps other
elastic gasses-either free, or dissolved
in the sap. When the sun shines these
gases feel the heat, and if they can ex-
pand they will. But if the tree is
sound, and the bark and wood unfrac.
,, tured in every part, there is no chance
for these gases to expand under the
influence of warmth The warmth
only increases their tension, orpressure
But cut, break, or bore into the tree
and then the gas can expand, and il
, expanding it will force the sap to flow
out of the wound. When the air grows
: cool again the gases in the wood con
tract, and the flow of sap ceases. The
same thing happens again and again
until the advancing spring starts tn,
:, buds into growth. The moment thi
. growth begins. the young leaf begin
also to collect from the atmosphere tn,
! carbonic acid gas which, transformed
into the new materials of growth, S,
thickens the sap that it can no longe
9 flow from the wounds made by the tap
e per. This seems to us to be the sun
and substance of what is known, or ma,
Il be logically inferred from what i
q known, about the sap question.
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