Weekly national intelligencer., 1851-03-01
SMITHSONIAN LECTURES.

The lecture Wednesday evening was delivered by DR..
b. A. GoULD, Of Cambridge, and the subject the Lou of
Graritatioa. ttt "<s
The energy which finds its expression in this law The
mighest OF all the forces which govern the physical uni
verse; and the only one which human power is unable in
any manner to subject its CONTROL The study OF Astrono
in its highest the study solely of this one law
BY Astronomy meant the science Of Asr which
not in be conlounded with that branch ofhe
study OF the heavenly bodies which belongs province Of
Natural History. These departments Of investigation
exist in the study of all things celestial or terrestria-,hs
realm Of the senses and the realm Of The elect.
DR.. G. then proceeded to state what this is and how
from formula simple the complicated results might
and did He considered It's action Were there
only two bodies in the universe for the when two
bodies were created relatively at rest relatively motion,
he showed the manner in which additional body
would affect by its perurbaons the symmeic motion prev
ousy existing He then proceeded give historical sketch
of the steps which led to the discovery Of the awom the
first discovery Of the true theory Of the solar system by Ko
pernicus the observations Of Tycho Bshe and the genea
cations Keppe to the detection Of the law n all its beauty
and universally by Newton
In closing he referred the Investigations of Mos
so and Faraday undertaken in the hope Of referring the
gavi,aive, the magnetic and the electochemies forces
the modified action of some higher law.
Dr. GoADBr commenced bis Lecture on Friday evening by
remarkng that the several forms Of digestive apparatus which
had been already examined and discussed carefully selected
from down to'he crustacea and from them the in
sects notwithstanding the great diversity Of form and
peIy of arrangement all destined the production Of
and the result viz the separation Of the nutrient
particles from the food which the animals referred
| rally subsist. 40 e
This nutriment destined to become blood and be
distributed every organ Of the body for M nouhment and
support and repair the and decay which every part
of living oganism constantly pone absorbed from that
portion of the nutrmena canal in which the separation of
the nutrient particles takes place in the higher animals BY
series Of vessels specially devoted this Junction. and called
acteas and by themoonveyed into the general circulation;
but in insects far know, the newly formed blood
chye ansudes through the paetes Of the intestine into the
free space Of the body. But subseve the import
ant function for which il destined must be mixed with
another element In other words the chys requires the ad
don of oxygen, which be separated from the atmo
sphere by the lungs in air breathing animals and from water
by the gills, in all the aquatic tribes
In the higher animals the inlet and outlet of the respiratory
apparatus is the that is devoted ohe reception Of food
namely the mouth. In insects the respiratory organs
provided with number of special mouths which perform
other function than that Of regulating the ngress and
egess of the atmosphere The number Of these breathing
mouths spracles is usually the Of pair for every
segment
muscles open and shut hem and with nerves Of sensation
to take alarm at the approach of exaneops matter and direct
the muscles to kind Of pasmodc contraction and closure
Of the spacle as happens with when food makes
tempt 90 the wrong way" These external spirace
which lateral in their posiion shown in the inegu
of the larva of beetle indigenous to this country, (os
odrma cremicoor and in section Of the caterpillar that
feeds on the The aquatic beetles arbreahing
insects they obliged and rise to the
face of the discharge the altered air contained in their
respiratory organs and nhale fresh supply from the amo-
sphere This process the work Of instant but nssmuch
the surface Of the pond covered with dust and exaneous
of all kinds in minute PARTICLES which would be forc
bly, driven into the paces the moment they opened
and produce convulon that would destroy e there
not most beautiful mechanical prevent such
contingency the spracles Of the aquatic beetle (dycs
arsinas) providedw Of bony processes each
Of the lips of the breathing mouth and those processes
covered with hairs thicky set diagonal I'M their direction,
and crossing each other inteminaby forming hair seve,
with meshes Of such nconcevable neness ectuay
exclude deleterous matter Of any kind This clearly de-
monstrated by the preparation. s.4ett
The internal breathing organs of insects have been
pared distribution Of artera boodvesses in the higher
animals They composed of three membranes
the internal layer, covered by tough elastic
thread which wound spray round the former, from
end Of this very extensive the other and this,
which forms the second middle coat covered by the third,
analogous the unc of higher animals The lungs
have not local position, in the majority Of animals and to
which the blood is conveyed by vessels that may obtain the
required oxygen but in insects the lungs 60 to the blood,
and for this purpose they distributed throughout the body
carrying oxygen every tissue, rendering the blood always
pure always vital and is this high condition Of esps
ton that mpars this class of anmas the surprising
gy and activity for which they conspicuous The air
tubes distributed through the whole length Of the locomo-
tive organs the claws which terminate the foot The
spay wound elastic admits Of compression by the COM
pound action the muscles of the limbs recovering its figure
the the pressure removed Many other remarkable
facts related connexion with this structure which the
lecturer illustrated by preparation Of the entire respiratory
organs of a caterpillar (cossus Ggniperda)
The structure of the heart considered This
gan placed the back in insects has thence been called
dorsa vessel" 1t is composed of number Of chambers,
generally eight in the larval condition. which communicate
with each other by Of internal valve Each cham
Der provided with pair Of external valves which
said open the free space in the body but really the
lecturer has discovered and demonstrated by preparation Of
the heart of the American cockoach, in the Huntean
collection Of England, into large SINUS which
loosely invests the dorsa vessel The whole phenomena Of
the circulation of the blood be beautifully trans
parent aquatic insects by Of the compound microscope
especially in the larva Of ephemera The pair of external
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