The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1838-09-28 00:00:00

LIVERPOOL MECHANICS' INSTITUTION.

LECTURES ON CHEMISTRY APPLIED TO THE ARTS.

On Wednesday, Dr. Kane, whose lectures upon this
science were so eminently successful in the spring of the
year, commenced a course of eight lectures upon chemistry
as applied to the arts and manufactures. The lecture-room
was crowded, the aisles below being. occupied by a nnmber
of persons unable to obtain seat room. Upon the entrance
Of the lecturer he was received with loud expressions of ap-
probation.
1 feel highly flattered, said Dr.-Kane, by the warmth of
the reception which I have experienced from you this even-
ing, because it encourages me to suppose that the manner
in which I developed this science when last I had the honour
of addressing a similar audience in this theatre, was not
unsatisfactory.
The province of chemistry which I have to consider in these
lectures is similar in many points of view,: bat dissimilar in
others, to that in which we were engaged on the former oc-
casion. In the course of lectures which I previously delivered,
it was my business to bring before you the phenomena of
chemistry in their similar as well as in their general form,
and to point outthe results of nature which are to be ex-
pected from the same causes. There is no science which
opens so extensive a field of investigation or rewards our re-
searches with such satisfactory results.
Having satisfied myself' that the dignity of chemistry will
be understood by what I have already stated, it will be my
study to folios; out the same phenomena in their application
to the arts and manufactures, premising beforehand that as
chemistry is capable of opening to us the most enlightened
pleasure, so we shall find that a knowledge of it is the founda-
tion stone of our national success in the arts and manufactures.
On the former occasion, in selecting my illustrations of the
facts which we were called upon to discuss, I chose those
which were capable of being brought before von in the most
elementary and attractive point of view. Although the ap-
plication of ehemistry cannot tail to be to a certain extent
attractive upon all occasions, I shall upon the present be
obliged to sacrifice the brilliant to the useful, as I shall not
allow myself to be called away from what is really useful to
that which is merely ephemeral or novel in attraction.
The substance which is above all others of the most im-
importance to the arts and manufactures is one which, since
its discovery, has at all times maintained its station at the
head of chemical substances. It is that to which, froth its pro-
perty of generating acids, the name ofoxygeu was first given,
• and which has been continued, although it has since been
found that acids are not exclusively formed by it. We find
it to be extensiVely distributed over the three kingdom's of
nature. In the atmosphere it composes more than one-fifth
of the atmospheric air, and in water it exists in still larger
• quantities, constituting eight-ninths of the waters of our
globes In the mineral kingdom we find it exists to the
amount of one-third. In the vegetable and animal, we find it
to a considerable extent, although not in such large propor-
tions, and performing such important services, that if it were
abstracted every living creature would cease to exist. We
shall find in real practice in the arts that every process is
connected, one way or another, with oxygen. Setting out to
contemplate the chemistry of the arts, I shall make one grand
distinction between my present and my former method of
treating the subject. Formerly, in treating of oxygen, I
placed before you the various methods of preparing it. Now,
however, my task is completely slifferent. I shall, in bring-
ing the subject before'you merely show its application to the
art, and not dwell upon the various processes for obtaining it.
-It is evident, front the extent in which it exists in nature, we
may obtain it from a vast variety of bodies. The only one
which I shall describe is that by heating a mineral, which we
shall find to be of use in a variety of manufacturing processes,
namely, manganese. • In this way we prepare oxygen for a
• vast variety of purposes. It is not perfectly pure when thus
obtained, but sufficiently so for all purposes in the arts.
This mineral contains a metal of very great and general use,
namely, manganese, combined with two portions of oxygen,
one of which it gives out on the application of heat, so as to
enable us to collect it in gasholders. Oxygen gas is trans-
parent, colourless, and a little heavier than the atmospheric
air, but not much, being in the proportion of 11 to 1(1. To
appearance it could not be distinguished from atmos-
pheric air, but a little examination only is sufficient to point
out the difference. For instance, we find that if we plunge a
taper into oxygen it burns more rapidly than in common air,
and that if it be immersed in a state of ignition only the ac-
tion of the oxygen upon it is of so energetic a nature as to
rekindle it. lu fact, all bodies which burn in atmospheric
air burn with much increased vividness in oxygen. In order
to show that this is the case, I shall take a portion of a sub-
stance which burns vividly in the atmosphere, but which we
shall observe to burn with much superior power in oxygen
gas. Phosphorus, for instance, as every person knows, is a
very combustible substance, and burns with great brightness
in atmospheric air, but in oxygen gas it will burn still more
brilliantly. The combustion of phosphorus in oxygen, as in
the atmospheric air, gives rise to the same products, but there
is a greater degree of light and heat given out by its combus-
tion in phre oxygen. Oxygen, in its simple condition, is not
applied to any purpose in the arts. Such au application
would be extremely expensive. We are, it must be remem-
bered, in the midst of a vast store-house of this oxygen—
the atmospheric air, from which we extract it in the bleachino,
of linen, and other purposes, to the due performance of winch
it is so highly important.
Oxygen is met with in the atmosphere, mingled with a gas
which was at first" called azote, from the circumstance of its
being unfriendly to life, but now more commonly nitrogen.
In order to prepare azotic gas, we may have recourse to a
variety of methods, but I shall bring butone before von, and
that a most characteristic one., When a substance burns in
the atmosphere it combines with the oxygen., as the azote
merely serves to dilute the oxygen. If we ignite a small
quantity of phosphorus in a cup; and place over it a bell-
glass, so as to allow it to burn in a limited quantity of at-
mospheric air, the combustion of the phosphorus ,will go on
until all the oxygen which the vessel contained is abstracted
by the phosphorus. A white powder will then be found to
have been formed during the process, called phosphoric acid,
by the union of the oxygen of the atmosphete with the
phosphorus. If we allow the vessel to stand until all the
flocculent phosphoric acid has deposited itself, we shall find
remaining in the glass the other compou.nd of atmospheric
air in the state of pure nitrogen. The effect of nitrogen
upon the combustion of substances is very singular. Thus, if
we plunge a ligtited taper into it, we find it instantly extin-
guished, the nitrogen possessing the quality of extinguish-
tig_ flame, or rather of not supporting combustion. Time
combustion of a body depends upon the play of affinities be-
tween the burning body and the gaseous body. Phosphorus
is incapable of combining with nitrogen, and, therefore, it
will not burn in nitrogen. Another very important use of
the oxygen of the atmosphere depends upon its powers in
promoting the respiration of animals. Every animal takes in
a quantity of atmospheric air, but this air is much changed
in respiration. '('he oxygen is replaced by a substance of a
different nature, and its bulk is much diminished. In fact,
every time we expire we metamorphose the oxygen into a
substance of a different and completely • poisonous nature.
We find a different action'carried on in the vegetable
kiog-
dom, as plants absorb carbonic :meld and etiitt mi*gen.
these counteracting principles the atmosphere is constantly
maintained in the same proportions, so absolutely requisite
for the general good of organised nature. Nitrogen, in its
isolated state, is not used in the arts. It combines, however,
with oxygen and with hydrogen in different properties, every
one of which, either directly or indirectly, is of great import-
ance. The most important of its compounds is that from
which it obtains its naive, viz., nitre or saltpetre. If we
analyze saltpetre; we shall find that it contains a large quan-
tity of potash, in combination with nitrogen and oxygen. If
we bring potash and lime into contact with atmospheric air,
so as to expose at considerable surface, see shall find under

these favourable circumstances that the nitrogen and
oxygen will combine and unite with the potash to form
nitre. The chemist cannot generate nitre in sufficient quan-
tities by this method, but the manufacture is carried on upon
a large scale by nature. Whereter limestones and calcare-
ous soils exist, particularly if they be mixed with clay, or
gravel, or animal manure, if they ate exposed for a number
of months in summer to the action of the air, provided they
do not become too dry, they will be found, when washed, to
yield a large quantity of saltpetre. In the East Indies nitre
beds exist naturally in very large quantities; and in the
central parts of South America there is generated an enor-
mous quantity of a kind of saltpetre in the same manner.
From these parts accordingly the nitre is derived. Suppose
a limestone soil to be exposed moist to the action of the at-
mosphere. The affinity of the soil for nitric acid is very pow-
erful, and in this manner it produces a junction between the
nitrogen of the atmosphere and the oxygen, which forming
nitric acid, unites with the base, and in this manner we have
the nitre of conimerce. The manufacture of the nitric acid
of commerce is very simple. If we take a quantity of nitre,
consisting.of potash united with nitric acid, and pour upon
it oil of vitriol, upon the application of heat the nitre is de-
composed, the potash unites with the sulphuric acid to form
sulphate of potash, and aquafortis or impure nitric acid is
disengaged in a vapourous form, and collected in a receiver.
In the rain which falls after a thunder-storm we shall find a
small quantity of nitric acid. Nitric acid is composed of
one equivalent of nitrogen and five of oxygen, or 14 nitro-
gen and 40 oxygen form 54—nitric' acid. This enormous
quantity of ox3gen which it contains gives to nitric acid its
greatest commercial value, and not any remarkable quality
of its own. It is a portable store-house of oxygen, and can
easily be decomposed wherever the oxygen is wanted. In
order to show this, it is only requisite to have recourse to a
very few experiments. In the arts the metals are used in an
oxydized form. The rust of iron, and an immense number.
of substances which we 51-01 have to examine, are only com-
b inations of the metals with oxygen, and these oxides where
they do not exist in nature are generated by means of acids.
If .c take a little nitric acid and pour it upon the metal tin,
there ensues a violent action. Orange-coloured fumes arise;
and a pearl white powder is formed, which is used in making
white glass, and in various other processes in the arts. Ni-
tric acid in the arts is not made in glass retorts as we
have described, but in large iron cylinders, lined with
tire clay. Nitrate of soda is principally employed for
this purpose. The heat is continued until the sulphate of
soda is tused, which is then used as a flux by brass-founders.
I shall advert to but a few of the combinations of nitrogen: In
order to generate nitric oxide we take a retort containing a

quantity of copper chippiugs, and introduce into it a little
nitric acid diluted with three times its volume of water. Bub-
bles of gas are immediately formed, and there is taken from
the nitric acid three-fifths of its oxygen. Nitric oxide is co-
lourless, and it is impossible for the eye to distinguish it from
atmospheric air, to which it is similar in specific gravity. It
is, however, characterized by this property, which is not
possess*d by any other gas whatever. that, when all Owed to
mingle with atmospheric air, it unites with its oxygen and
generates very remarkable red fumes, by which nitric oxide
can be very readily detected. In order to make this still
more remarkable 1 shall fill this globe with oxygen instead of
atmospheric air, by first removing the latter by means of the
air pump, and then connecting the globe with a vessel con-
taining oxygen. if we place this globe of oiygen in'con-
nection with a jar of nitrid oxide vtry red, dense fumes are
immediately produced. By this means we have nitrous acid,
which can be collected in a solid form by condensation and
cold. These red fumes are easily soluble in water, and we
find that by their combination we procure a very powerful
acid, more powerful than nitric acid. Nitric oxide supports
combustion under particular circumstances. If the nitric
oxide be very powerfully heated it is decomposed; thus when
a body introduced into it is burning very feebly it is extin-
guished, but when it is burning very powerfully it continues
its action and decomposes the nitric oxide. Nitrous oxide is
a substance somewhat resembling nitric oxide. It is well
known under the name of laughing gas, but as its intoxica-
ting qualities have not been practically applied I shall pass
it over with this notice. One very important application of
a compound of nitrogen is in the manufacture of g,unnowder,
and the artificial fires. Gunpowder is composed of charcoal,
saltpetre, and sulphur, in proportions which differ in different
countries. The proportion of saltpetre, however, is 75 per
cent. In the manufacture of gunpowder there are two cir-
cuinstances which require to be taken notice of; the first is,
that the saltpetre should be perfectly pure. The saltpetre of
commerce is frequently contaminated with muriate or nitrate
of magnesia and nitrate of soda. The salts of magnesia are
deliquescent, and so is the nitrate of soda. The admixture
of either of these substances would, therefore, communi;ate
their property of becoming moist tl the gunpowder, and it
• • • / uscil is vry-
mc--r e t as es wt co in a quantity of carbonate
of potash, which is likewise deliquescent, and-cause the pow-
der to he subject to become moist. These things being at-
tended to, the manufacture of gunpowder is perfectly me-
chanical, the granulation being effected by pressure through

,sieves.
Sulphur is not limited to the mineral kingdom. It is also
met with in the animal and vegetable dominons, but in very
minute quantities. In the animal kingdoms it exists in the
brain and in the bones, and in the eggs of birds, owing to
which silver spoons ate discoloured upon using them in eating
the eggs of poultry. In a variety of plants of the cabbage
and stock family, there is a quantity of sulphur, which is the
cause of tbe bad smell exhaled by the plants when in a state
of decomposition. From the mineral kingdom however, it
is that the sulphur of commerce is always obtained. It is