The daily crescent. [volume] ([New Orleans, La.]) 1848-1851, 1851-02-01
Lyceum Hall Lectures.

Last evening" DR.. j. L. Smith delivered the
fourth of his series of lectures on chemistry in the
above Hail. His subject was the combination OF
oxygen and hydrogen, the two elements which he
had treated and exhibited the properties of in the
preceding lectures Previous, however, to entering
upon his subject proper, he exhibited considera.
BILE sized balloon, made of gold heaters skin, and
in the shape of an elephant, which he had inflated
previous TO the lecture, with hydrogsa gas and
which he now disengaged, when the creature rose
buoyantly in the air, till its further progress was
prevented by the lofty ceiling, against which for
time it remained, and in due season made safe
and gradual descent. If the audience Were in any
degree disappointed the preceding evening with the
little hydrogen balloon which would not rise, they
had it more than compensated for on this, in see
| ing the elephant" make his aerial gyrations; and
the lecturer, too had the satisfaction OF exhibiting
what 1t was his Chief purpose TO exhibit, and ex,
piain' by the introduction OF the experiment, the
exceeding ghtness OF hydrogen gas ana Its use In
| balloon ascension
he had prepared quantities OF oxygen and
hydrogen gases ~h'ch ne haa nl,1eo ana placed
IN 's'''-s -. 'no pr'po'e' ~"o Oe,o.e enec'-
'"e s' ~, ~" VI '"e'e nc eAp'a'neu 'na'
s..;a r"'.e1 ' ~. ~ ee"n'e
ah,os, ,,,,s ,,Lan -. ,ha s,,nd,rd - a.
chemist comn,res the weight of The rest bv-ovv,sn
tbsn w,s fornsd WHOM i combined ,v;,h ~.
formar IN do so in the proportion Of EIGHT tho
resulting comnound being nine. Either of these
bodies again. when thew enter into combination
with any of the other elementary bodies. do so in
this proportion the other elements observing the
same regularity in their mode of combining so that
when we once ascertain what is the combining
equivalent of any one body with any other one
whatever we are sure to find it enter in the same
exact proportion in every compound which it NAV
enter into. They may, and often do, form CON-
pounds where we have two, three and four equiva-
Tents of one elementary body, entering into and
combining with single equivalent of another ele-
mentary body, but they never, he said, perplex us
by forming combinations when half or third of
any of these is found always in the exact definite
numbers, and which set forth in all works on
chemistry. knowledge Of this important law of
the combinations of bodies, was highly necessary
to correct understanding of the subject of chemi
cal changes, and although without this, little
para.ive progress could be made, yet he must refer
them to works on ike subject, as in a short and
popular course like the present. he could not give it
the attention 1t required
He then went on to illustrate the manner in
which the combination OF oxygen and hydrogen
was effected. He showed that the requisite pro-
portions of these elements for combination were
placed in immediate contact with each other, yet
that no chemical change resulted, and this would
remain to be the case, no matter how long they
should be so kept. 10 effect union, 1t was neces
sary to call in the action of third body; and this
third body, though required to set the chemical
affinity Of the others into full play, did not take any
other part in the union which they formed; it
seemed to set one point OF them into notion which
instantly became propagated to all the other parts
OF the mixture, an explosion In snort was the resu
when heat and light were given iorth. Inc uitl
mate result OF the explosion with the ga es refer
| red to, he showed to be the formation OF water
This he did by setting flame to jet oil these gnlted
and holding bellglass over it, when an evident
deposit of watery vapor formed on the int
| ror and tricked down the side He exploded the
mixtures in the same way BY passing an electric
spark through these gases in little apparatus for
The nurnose and also in small brass cannon which
No had oh,raed with tho same both Of which ex.
| -I-,-I - I..sa.;-. T. n H.. go.