The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1852-01-29

The Professor commenced his lecture BY recapitu.
iatipg the subjects alluded to in that which pre-.
ceded it, in relation to the mechanical properties
of the atmosphere, in which he referred more par
ticulary to the proofs that he adjucei Of its
riality, weight, AID elasticity, daring which, he
said, he had entered into the consideration of its
relations as the vehicle Of sound, and as exercising
strongly magnetic influence Owing to want Of
time he had been compelled to omit allusion to its
other properties; among which was that of color,
to which he had merely incidentally referred whom
treating Of indexion and refraotion. Although
color Is not perceptble in contracted space, yet
when the view extends in horizontal, vertical,
oblique direction, then there return the rays Of
light that give the rich cerulean color, which, as
the acolivity of the mountain is assembled, assumes
deeper tint until at the highest elevation-as at
Mount BlaDc-the sky becomes of the deepest
black So certain is it that the color deepens the
observer Raves the earth, that Saussiere invented
centrivance by which. owing to the regular grada
ton that takes place he was abe at each
stage to ascertain his height from the plain below
by the change it indicated in the color Of the atmo-
spheres thus establishing its relationship with light
After explaining the notifications Of tho atmo-
sphere by whichthe color of the clouds varies from
abe heecy wilderness Of MONDAY to the darkest
shades OF approaching night, he described the
manner in which those changes are effected, by
altering the combination Of the three prsmatic
colors-blue, red and yellow, bringing out those
tints that characterize the landscape and give to
the sky it's beautiful coloring at the time of the
Using and setting sun; in viewing which, he said,
it was impossible cot to be sSruak with the benei-
cent tendency OF the laws OF nature and the ad ipa
ton OF the atmosphere around for the cultivation
other gifts In referring to the barometer, he took
it for granted that all present understood what it is,
and what are its uses; and yet it would be worth
while to consider what were the centemplations Of
Torricelli when he invented the instrument, and at
time when his discovery viewed with doubt.
AT the present day every navigator finds it neces.
sary to have in his possession for there is not
wave of air that may not be measured by the ba-
rometer; and also the oscillations that at certain
times prevail during the day. Not only this, but
by discoveries recently made, particularly at st
Helena, it has been found that there is tidal
movement Of the air, in obedience to the move
ments of the moon. answering to the tides of the
ocean, and pointing its apex to that luminary,
thus serving to illustrate in another aspect
the sublime simplicity of natures laws.
Prof Rodgers here called the attention Of his audi
tory to several rude drawings in his possession
among others was one of an Etruscan lamp, such as
are discovered to have been in use in Hercuaneum,
previous 70 the time of the Caesars and which
show that, although men in the more distant ages,
had made some proficiency in the study of nature,
yet they had never been led TO the discovery OF
her great truths. The representations Of a Chinese
air pump and watering pot, he said, only served to
prove that scarcely any progress had been made in
that country, in knowledge Of the laws of nature,
or OF what man can effect N controlling her power
He then proceeded to consider the component
gaseous portions, contains wafer. The gases
are those of oxygen nitrogen, and carbon. This be
illustrated by experiments-not, he said, for any
pyrotechnical display such exhibited by dealers
in philosophy, his object being rather to improve
than for effect. lie should, therefore, only
select few for the calculation Of facts which
could not be demonstrated Ia any other way.
He commenced with nitrogen and presently, he
said, it would be perceived that this is an active
agent; and it is doubtful whether there exists any
structure that is essentially vital, which has not
nitrogen rs an important component part, while
Others that are destitute of vitality, also dest
tute nitrogen He mentioned this, he observed,
because from its negative character, it had been sup
posed it was only employed to dilute--shan which
nothing could be more ncorrect for to its negative
properties its adds positive effect 1t also forms
four ffhs of the atmosphere, the other fifth being
oxygen. Professor Rodgers here perfer med the
experiment OF burning steel, by inserting it IN
glass vessel filed with oxygen gas Bat the efsct.
wes, to coat the inside of the vessel with oxide Of
iron which colors all the red soil and many Of the
rocks of the globe, and which has been caused by
the combustion ofiron. He performed some other ex.
rerimeDts, to prove that burning charcoal or sui
phur generates an acid converting blue liquid
into red Nitrogen and oxygen constitute
most Of the atmosphere; and although nitro
gen IL much heavier than oxygen, yet it hal
been found impossible to detect any ditfer in
the proportions; at whatever height the air may
be anay ged, these are invariably the same. Inl
is reterabe, he said, to an important law, that wa
discovered by an English schoolmaster, who, with
veries OF modern times, which will last Throughout
all time. Among Others was this:-that whatever
are the relative weights ct these gases, they will
net form chemical combination, but will
mix with each other; and each Of them as
regards the other is to be considered vacuum
In explaining any subject in nature, he said, it
was necessary to bring the particular fact connected
with it under some general law. IL is mans wise
and happy vocation to gather up facts and arrange
them in order and from these to deduce the laws Of
the universe the foundation Of which is with Him
who laid them for ever and ever Professor Rodgers
then passed on to another Ingredient of air, which
abundant,y dfuscd; this is hydrogen, which con-
stitutes eight nnths Of water He then proceeded
TO consider the properties of hydrogen, which IS
lighter than atmospheric air. and when taper was
introduced into vessel containing this gas, the
fame was extinguished, but, as the hydrogen con-
tinued to blaze al the surface the taper was re lii
when again withdrawn. Professor Rodgers here
called the attention Of mis- audience to the nvesti
cation Of carbon, which forms to great extent the
framework Of the globe The specimen of char
coal that he exhibited, he said, was an artificial
product, but there ID substance garnered up, in
which the principal Ingredient is carbon-he al
form OF black lead, which is pure charcoal; and the
diamond Is another elementary form of carbon
which has the same origin vito coal, and is vegc
table product, which has become crysteIllzed, and
possessing so much briiancy that no no one would
suppose tnat it is Identical will tn, common
exuvia Of our hearths. Yet such ~ the 'act, the
same elements often producing different moues OF
the aggregation Of the materials Of which bosy
is composed. Carconic acid gas is not only
heavier than atmospheric. air, but it extinguishes
life lie said be should consider one or two
Of its properties, aut then close his lecture
When oumbined with water, 1t possesses solvent
powers, and il is the great agent by which nutTi-
ment is conveyed to the roots ard stems OF plants
and by which trees are formed; it is the agent by
which rocks ore undermined, and the structure OF
the earth Is changed Thus, BOT only are wondrous
changes effected by tAis powerful but insidious
agent in wearing down the SOIL but also in the
dsintegration OF rocky substances CarSonic acid,
descending in rain, penetraits the Garth, and not
nvain; for each of these portions of water is d,s
solving portions Of the soil, acting az solution
Even common water acts as a solution, and Is
doubtless, producing charges IN the depths OF the
globe; and when carbonate Of lime occurs under
ground the destructive effects Of the solvent proper
tes of water ana caroonic acid gas are everywhere
perceptbe. If we would turn 70 Pennsylvania,
maryland OF Virginia, there vii OF found nume-
rous lost rivers. IL not the river that has been
absoved. and thus disappeared, but it has made a
I,xt hn topt Of IL.