The Pulaski citizen. [volume] (Pulaski, Tenn.) 1866-current, 1873-10-16
CURIOUS AND SCIENTIFIC.


The distinguished psychologist, BrucIe,
has been making some investigations
upon the substances produced In the
digestion of the heterogeneous consti- /
tuents Of food, ordinarily called car
bchydrabes. he distinguishes. in the
first place, between the dextrinszhich is
coiored red by iodine and that which is
not colored at all by this reagent, call
ing the former eEythrodextrin, and the
latter achrodextrin. Commercial dex-
trim, made by roasting raw starch. is
mixture of erythrodextrin and soluble
starch or amidulin. That made by
Payen's method-in which the starch is
moistened with nitric acid, dried and
roasted-contains besides erythrodex-
trim, both achrodextrin and sugar.
Starch treated with sulphurie acid
yields first amidulin, then erythrodex-
trim, then achrodextrin and sugar. The
process Of mailing produces achrodex-
trim In quantity. When now, the con-
tents of the ston.achs Of dogs, killed
from one to five hours after meal made
up mostly of starch, were analysed,
large quantities of soluble starch and
of erythrodextrin were found, while
achrodextrin and sugar existed only IN
traces in the small intestine on the
other hand, there was no erythrodex-
trim, but sugar was always present. The
small amount of sugar in the stomach is
ascribed to the checking influence of the
acid of the gastric juice upon the saliva
the action of this very acid producing.
however, the soluble starch present,
while the conioined successive action of
the saliva and the acid produces a part
of the erythrodextrin. The chief part
of this substance Brucke has proved is
due to the Tactic acid fermentation,
which he thinks is normal digestive
process, intended to prepare the starch
for more rapid transformation into sugar
in the duedellum, under the influence
of the pancreatic juice.
INFLUENCE OF FORESTS ON THE TEN
PERATURE OF THE GROUND. Bava-
rian physicist Ebermayer has investiga-
ted the influence of forests on the eli
mate of the neighborhood as shown by
the numerous observations recorded
in that kingdom. Among his conclu-
sions are the following results as to the
temperature of the ground, determined
by thermometers sunk to the depths of
one and six inches and of one, two,
three and four feet. For the upper
layer of earth, within one foot of the
surface, the minimum monthly mean
temperatures occur both in open and in
wooded regions in the month of Janu-
AIRY only on the high mountains does
the lowest temperature occur in Febru-
airy. The temperature increases from
February ON, until its maximum in
July; at the high stations, only, does
the maximum occur in August. From
July or August the temperature decrea-
ses 70 January or February. To the
agricultural interests it is especially
| important to note that the monthly in
crease of temperature is most rapid In
May, and is nearly as great in April it
is least in June and July. Concerning
the strata lower than one foot, Eber-
mayer finds thnt the monthly incaease
in temperature is greater in June and
July than it is in the upper stratum.
The loss of temperature is, in the upper
stratum, most rapid in November and
October, and least in the coolest
weather in January and February. In
forest-cOvered places the lowest temper
allure occurs in February, and continues
to june, during which interval the
ground is cooler than the air in July
and August the ground is somewhat
warmer than the air. The greatest diff
ference between the temperature of free
and forest land occurs in May, and the
least in June. The fluctuations in for
est land are less than in open ground.
The influence of the forest in prevent
ing the cooling of the ground by the
radiation of its heat is most noticeable
in October and Fovember, and least in
january and February.
NEW Form OF ExPLos1vEs.-Sir
Charles w. Vincent makes communi-
cation to Iron in reference to new ex-
plosives, the object being especially to
call attention to recent patent by Doc
tor Sprengel. The theory of explosion
is based upon the rapid disengagement
of an enormous volume of gas in a con-
fined space this being produced in
such quantity as by its expansive pres
sure to accomplish the object of irving
and bursting asunder the inolosure. As
a general rule, these explosives, like
fire and water, are very good servants,
but very bad masters, and their tendency
to go Off when their services in this di-
rection are not needed is the frequent
cause of great amount of mischief,
both to life and property. The object
of DR.. Sprengel has been to devise some
method by which the components of the
explosive may be kept apart until the
moment when needed for use, so that il
either be subjected to the action of heal
or percussion, no damage will be the
result. The one being a combustiblt
and the other an oxidizing agent
neither will act injuriously unless IL
combination with the other. These
combustible and oxidizing agents, &C
cording to DIR. Sprengel, should befron
different states of matter; thus, If the
one be solid the other must be &
liquid, and he proposes to place the
solid, but finely divided oxidizing sub
stance in n vessel or chamber, and tC
add to it when needed for use the liquid
combustible, and TO explode the two by
means Of detonating fuse or percus
sion cap. The fluid oxidizing agen
preferred by him is nitric acid, Will,
the solid eombustile may consist of suel
nitro compounds as are not explosive
such as nitro-naphthaline and the nitrat,
of aniline. Aud again, the solid chic
rates, per-chlOrates or nitrates of tas
stun may be used to oxidize bi-sulphid,
! of carbon. benzole, nitro-benzole, alec
hol, either. oils, ect. The hest result,