The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1838-10-02 00:00:00

and in itself incombustible. It does not, however, support
the combustion of bodies in the same manner as oxygen. It
is not colourless, but of a pale greenish yellow, from which
circumstance Davy gave its name. If we take a little of the
metal antimony and drop it into chlorine, it burns very
beautifully, in fact we have a shower of sparks which arises
from the combination of the chlorine with the antimony. if
we introduce the metal arsenic into it, we have a stilintore
splendid combnstion. Dutch metal likewise bolos in chlo-
rine. We thus observe that chlorine, like oxygen, supports
combustion, and that those bodies which burn best in chlo-
rine are quite different from those which burn best in oxygen.
A taper, which burns so well in oxygen, burns very faintly
in chlorine; whilst metals, which do not burn in oxygen,
burn spontaneously in chlorine. The preparation of chlorine
is very simple. It' we take a quantity of the per-oxide of
manganese, which consists of the metal manganese combined
with two portions of oxygen, and add to it, in a retort, two
proportions of spirits of salts, (common muriatic acid,)
which consists of chlorine united to hydrogen, we shall, on
the application of heat, have the following result:—The
oxygen of the manganese and the hydrogen of the muriatic
acid unite, and form water, whilst one-half of the chlorine
remains with the metal manganese and the other flies off.
In this way we obtain one-hall the chlorine which the spirits
of salts contain. There area variety of other methods, of
which a very beautiful one was communicated to me by
my friend Mr. Wilson, who is connected with this institution
as Professor of Chemistry, founded on the decomposition of
the oxides of chlorine by muriatic acid. The salt termed
chlorate of potash consists of six equivalents of oxygen, six
of chlorine, and one of potassium. If we pour upon it muri-
atic acid, which is a combination of six equivalents of chlo-
rine and six of hydrogen, we have the oxygen and hydrogen
in the proportions to form water, and all the chlorine of the
muriatic acid is set free. There is this advantage attending
the process that we obtain all the chlorine of the muriatic
acid without any inconvenience or dirt, so that is a beautiful
mode of operating for small experiments. Otherwise, from
the cheapness of the black oxide of manganese it is the best
adapted for operations upon an extended scale. We have
for this purpose large leaden retorts, surrounded by iron
jackets in such a manner that steam can be introduced be-
tween to heat the leaden retorts. Into these retorts the man-
ganese and muriatic acid are introduced, or common salt,
sulphuric acid, and manganese. When either of these com-
binations are heated by the steam chlorine is liberated, and
may be collected in proper vessels.
When chlorine was first discovered it was used in the
gaseous form. '!'his has since been given up in consequence
of the ill effects which it produces upon the human lungs. It
is now chiefly used in combination with lime or soda. In
order to exhibit the bleaching properties of chlorine it is only
necessary to perform an experiment similar to that which we
have already made with the sulphurous acid. Here is a glass
containing a bouquet similar to that which I first used. And
here I shall show the convenience of Mr. Wilson's method
of at once obtaining small quantities of chlorine without
much trouble. You will find that according as the disen-
gagement of the chlorine proceeds that the colour of the
flowers will very rapidly disappear, and we shall have in this
case as complete a disengagement of the colour of the flowers
as in our former experiment, with this difference, that the
bleaching with the chlorine is real and permanent, that with
the sulphurous acid only temporary and apparent. In the
one case we shall find it impossible to restore the colour, and
in the other we shall be able to do so. By immersing pieces
of cloth died red with Turkey madder, or blue with indigo,
in a solution of chlorine, the colours will be discharged. The
presence of water is absolutely requisite to the bleaching of
fabrics, for if a piece of coloured cloth is introduced into
chlorine gas, deprived of moisture, no action ensues. Thus
we see that chlorine itself has no power over the colouring
matter, but that its action depends upon a secondary effect.
It, in fact, results from there being oxygen set free, and
this oxygen going to the colouring matter. Therefore, as
the chlorine does not contain any oxygen the liberation of
this element must be a secondary effect. Indeed, in all
cases of bleaching by chlorine, there is water present, which
is decomposed by the chlorine: the chlorine takes the hy-
drogen of the water, forming muriatic acid, whilst the oxygen
of the water is thrown upon the colouring matter, which is
disengaged, and we have an oxide of the colouring nu.tter
formed which is in itself free from colour. Whether we use
the chlorine in a gaseous or liquid state, the same effect is
produced, provided water be present. If we add a little of
the solution of chlorine in water to the blue infusion of cab-
bage, it is turned red; but it. more of the solution of chlorine
is added, the colourint, matter is discharged. The fact. is,
that in the process of bleaching the chlorine is converted
into muriatic acid, which produces a complete reddening of
the blue cabbage.
Chloride of lime, which is now chiefly employed in bleach-
ing, is a white powder known under the name of bleaching
saits. It is a substance of very irregular composition, so that
it is important to any manufacturer to be in the positron to
satisfy himself of its actual strength. This is done by means
of a variety of processes. To the solution of chloride of lime
in water a little sulphuric acid is added, by which means the
chlorine is liberated from the lime, and we have what is
termed a bleaching bath. The chlorine is conducted into
leaden chambers, containing a number of .perforated wooden
shelves, upon which the lime is placed. The lime is allowed
to remain f.oni 40 to 6U hours in this situation, until it has
imbibed a sufficient quantity of chlorine, when it is packed
up in casks for commercial purposes
Muriatic acid is generated by the action of sulphuric acid
upon sea salt, which contains muriatic acid and water. Now
common salt consists of chlorine and the metal sodium.
When oil of vitriol is poured upon common salt, the hydro-
gen of the water unites with the chlorine, and the oxygen
with the sodium, and the chlorine and hydrogen pass off in
the state of gaseous muriatic acid. When chlorine and hy-
drogen are united in the proportions proper to constitute
muriatic acid, they will explode in the same violent manner
as oxygen and hydrogen, upon the application of flame, and
touristic acid will be the product. The only remarkable pro-
perty of this gas is, that it is rapidly absorbed by water, so
much so that it cannot like other gases be collected over
water. For scientific purposes it is collected over mercury.
Muriatic acid gas is transparent and colourless; it is touch
heavier than atmospheric air, and if we conduct it to the
bottom of a glass vessel by means of the beak of a retort, it
will expel the atmospheric air, and occupy its place. if a
tube, closed at one end, containing muriatic acid, is immersed
with its open end in water, the latter will rapidly combine
with the muriatic acid, and fill the vessel. The inuriatic acid
of commerce is merely a strong solution of muriatic acid gas
in water.

As in the former lecture, Dr. Kane illustrated his subject
by a erect an exceedingly interest-
ing nature. On Wednesday he will treat upon the manu-
factures of metals, and the mode of preserving iron from rust.