Vermont farmer. [volume] (Newport, Orleans County, Vt.) 1870-1877, 1874-03-13

position OF tne sap OF the several species dlf-
fered remarkably, according to the date Of
Aow, and especially the time Of its beginning
This singular periodicity, peculiar to every
species, demonstrates that the absorption of
water by the rootlets is not caused by os.
NOSE. or any other mere physical force, but
is the result Of the specific life which imparts
to every plant its distinctive characteristics
In regard to the circumstances which az
feet the flow Of sap from the sugar-mape
the following results have been arrived at.
A careful comparison Of the daily weight OF
sap from several trees with the meteorologic-
al observations of the same period, conclu.
sively proves that while the general flow
corresponds with the season, rising to a max
imum and then declining. yet the daily aud
hourly flow varies with the weather. The
most unfavorabe weather is that which is
either steadily and severely cold or uniform
ly warm and foggy, while the best sap.days
are such as are bright and warm at mid-day,
but preceded by freezing nights. Such va
riations Of temperature as affect the flow of
maple-sap are most likely to ocur when the
ground is covered with snow, because the
heat Of the sun during the day cannot then
accumulate to moderate the cooling influence
Of the night The most probable explanation
Of the effect of these alterations appears to
be that the outer tissues of the tree are par
| tally empted Of their contents by the con-
tracing influence Of cold, the sap being driv-
en- into the heart-wood of the higher parts of
the trunk. Meanwhile, absorption goes on
as usual underground, and thus, when relief
is afforded by the expansive influence of the
SUM- the sap rushes back to the surface and
flows abundantly.
Observations by Blot in France, on the
poplar, aud by Nevins, in Ireland, on the
elm, seem to show that the sap is thus forced
BY freezing wcather'from the outer wood and
branches into the hearts of trees
To determine whether sap would run from
the heart-wood Of a sugar.tree, a piece Of
gas-pipe was sharpened and driven snugly
into hole six inches deep. From this spout
the flow was regular and long continued, but
not quite as abundant as usual. This proves
that the spring sap usually enters and fills
the heart-wood as well as the alburnum.
Another tree was selected and a piece OF
bark five inches long and three inches high
was removed from the outer layer Of wood,
and piece of sheet-iron driven into the bark
below to catch the sap, which flowed very
profusely but stopped very early. The tree
from the heart of which the sap was taken
as above described, flowed eleven days longer
than the similar one from which only piece
Of bark was removed, but the latter afforded
twelve pounds more Of the fluid.
In the case of tree tapped on the north
| nd 81 ~
found that the north spout yielded daily
about twice as much sap as the south spout
and continued to flow nearly two weeks lon
ger The tree was tapped March 18th, aud
yielded seventy pounds of sap, containing
two and half pounds Of sugar.
In order to discover whether the sweet
ness of the sap was tie same in all parts o.
the tree, spout was inserted into healthy
maple, which had never been tapped, at tn,
usual height, and fifty feet above this anoth.
er spout was set into the trunk where it wa'
about FIVE inches in diameter A limb thir
, ty-fve feet from the ground was also cut wher,
it was one inch in diameter In seven hour
the lower spout had bled six pounds of sap
the limb, two ounces. and the upper spout
, not drop. Similar experiments on differ
: ent trees showed that the sap flowed mos
freely within twelve feet of the earth, ant
5 that the flow diminished rapidly above Thu
2 height.
} This fact corresponds with the curious re
suits obtained in observing the pressure o.
the sap as indicated by the mercurial gauge
which seem to show that the flow is caused
by the absorbent power of the roots forcing
, water into the tree. The rapidity of tn,
bleeding or weeping as the Germans say, i
modified by the season, the temperature anC
, the time which may have elapsed since 1
previous flow.
1t appears evident, therefore, inasmuch a
most trees will not bleed at any time, and a
even in the maple the sap rarely rises more
, than twenty feet from the ground during tn
, spring flow. that the development of leaf anC
flower buds is not usually affected by any
, mechanical pressure lof the sap forced into
them from below. Their vitality is stimu
lated to activity by the genial influence o
the sun, and their growth is, in its beginning
, caused by the assimilation of organic sub
, stances accumulated during the preceding
season of vegetation.
Experiments upon the roots of maple
proved that sap flowed from both ends of I
: cut root, and that il all contained sugar
In regard to the amount Of sap yielded BY
: the sugar-maple and its percentage of sugar
further observations are needed. The larges
flow during any one day last spring from
l healthy shade-tree of this species, measuring
e six feet and FIVE inches in circumference
b occurred March Odd, and amounte to tel
9 pounds and three ounces from two spouts
i A similar tree, however, bled from two orr
, fees on the 10Th Of December, 1873, sixteel
4 pounds and seven ounces of moderately swee
1 sap from which excellent sugar was made
4 On the 7th of November sap was gathered
g from the latter tree which was found to con
} tain only about one.half as much sugar a
e was observed in that which flowed las
n March. Whether the total amount of su
s gar obtained from tree can he much in
creased by multiplying the number of spout
inserted into j., we have not determined
though Mr. Parker d. Hubbard, of Sunder
land, an experienced sugar-maker has give
. the opinion that it cannot. His custom is Il
bore two half.inch holes about two inches il
depth into ordinary trees while four spout
: and two buckets are used in the case Of verl
g large trees.
r Among the interesting facts relating h
this subject in Emersons Report on tn
Trees and Shrubs Of Massachusetts,, are tn,
followiug A tree in Bernardston is said +
e have yielded barrel of sap in twenty-fou
t hours, and another in Leverett one hundre,
n and seventy-fve gallons in one season. Tn
r average annual product of sap from the suga
1 maple is said to be from twelve to twenty
' four gallons, and the amount of sugar fror
|. two to three pounds. Instances are given
n however, in which the yield from a singl
|. tree has exceeded thirty pounds in one sea
sou.
h Sugar may also be made from the sap Q