In a former number we directed attention to the many remarkable
properties of the air we breathe, and pointed out how dependent we are
for comfort and even existence on the maintenance of the air in a state
fit for respiration. The difference between good air and bad air can be
easily collected from that article; but as the peculiar conditions of the
air which are capable of affecting health deserve very careful
consideration, we are tempted to resume the subject.
The even balance which, as was explained, is struck between the two sorts
of breathing, that of the animal which gives out carbonic acid, and that
of the vegetable which takes it in, is capable of maintaining the air
upon the large scale always in the proper state. But in order that the
people may be benefited by this wise arrangement, it is necessary that
they should be living abroad in the open air and in the fields; that a
man, in proportion as he destroys the oxygen of the air, should have
around him plants to give out an equal quantity in its place; that, in
fact, mankind, in order to avail themselves of the providential security
for breathing permanently good air, should live out of doors, engaged, at
least principally, in agricultural employments, as was the condition of
society in the early ages, and in some portions of the globe to a certain
extent is so still.
But in countries like ours, where vast numbers of families are collected
in cities, with narrow streets and lanes; where an open place like
Stephen's Green or Merrion Square is anxiously sought after, and
disproportionate rents paid for the houses which are around it, this
immediate restoration of the injury done to the air by breathing, and the
burning of lights and fuel, cannot occur. The air is vitiated
permanently, and those resident in towns require for their health's sake
to understand how the evil may be rendered as small as possible. Even in
a town, the total quantity of air is so great, that if it all come into
play, it can be but slightly injured. But such is often not the case. How
often, when there is a fine healthful breeze outside the town, do we
find, on entering a narrow street, the mass of air perfectly motionless,
and all the mischievous vapours which are produced, collecting until they
become almost irrespirable. This is a great source of disease in towns;
and to prevent or remedy it, requires but frequent change of the air
which a room or a street contains: it requires but ventilation.
It is by means of a fireplace that a room is generally ventilated. The
air which has served for the burning of the fuel is thereby made very
hot, and hot air, being much lighter than cold air, rises up the chimney,
generally mixed with soot, and is then called smoke. According as the
hot air leaves the room, cold air enters to supply its place through the
open doors or windows, or, if these be closed, through every little
crevice which can give it passage. There is thus produced a rapid current
of air, or draught, as it is termed. The air vitiated by the breathing of
persons in the room is carried away along with that vitiated by the fire,
and at any one moment the air in the room is found to be almost
completely pure. It is therefore to proper ventilation that the
inhabitants of towns must look for the maintenance of health. Disregard
to this precaution has been the means of increasing to a frightful extent
the mortality of large cities, and instances have been given, where an
infectious disease, which had ravaged a number of low and confined
streets in a large English town, stopped suddenly, and avoided a street
otherwise no better than the rest, but which had been kept clean, and the
rooms ventilated, by the exertions of some well-informed persons. For the
preservation of the health of the poorer classes in large towns, medicine
is of far less importance than cleanliness and ventilation.
We are sure, however, that many of our intelligent readers are ready now
to start an objection to the account just given of the cause of bad air
in cities. If the air of a city be injured by the large quantity of
carbonic acid which is formed, a city should be the best place possible
for the health of vegetables. If the air which is bad for man be good for
plants, the vegetation in a confined street should surpass, in brilliancy
and verdure, that of the most open and best attended gardens. It is true,
unfortunately, that the only produce of our once industrious Liberty is
now the grass which is growing in the seats of former bustle; but we have
not even the satisfaction of knowing that that flourishes. It is pale,
sickly, and stunted; for the air of the city is vitiated by causes
different from that which alone has hitherto occupied us, and these
causes are as injurious to plants as to man. The carbon of our fuel
produces, in burning, carbonic acid, but carbon is not the only substance
in ordinary fuel. Most coals contain sulphur, and in burning, this body
produces sulphurous acid, also a gas, which is highly irritating and
poisonous, particularly to plants, and which, mixing with the air,
renders the city as injurious to the organization of a plant as the
carbonic acid to the respiration of an animal.
To render air fit for respiration, it is necessary to do more than keep
the proper quantity of oxygen in it; the carbonic acid must be taken
away. Plants, our readers have already remarked, do both, and hence the
admirable fitness of external nature to the objects for which the Creator
has designed it. If the carbonic acid were not taken away, all animals
would be poisoned, even if the proper quantity of oxygen remained, for
carbonic acid is a positive poison, which kills by acting on the brain
like opium. A person can live, breathing with only one lung; in the
disease of consumption, an individual may live for months with only one
lung, or even only part of a lung, remaining fit for use; but if
perfectly good air be breathed with one lung, and carbonic acid with the
other, the person will be poisoned after a very short time; consequently,
it is of great importance to prevent the accumulation of carbonic acid,
even where it is not produced at the expense of the oxygen of the air.
Carbonic acid is indeed produced in a great variety of ways, besides by
animals in breathing, and fuel in burning. It is remarkable that it is
only the green parts of plants which breathe as has been described; the
leaves and stems giving out oxygen, and absorbing carbonic acid. The
flowers and the ripe fruits of plants act on the air in the same way as
animals, and hence deteriorate it; and the rooms where stores of fruit
are kept, are known to be very unwholesome, and persons have been
suffocated by sleeping in a room where there was a very great quantity of
flowers. Oils, particularly drying oil, and spirit of turpentine, act on
air also, absorbing oxygen and giving out carbonic acid; and the air of a
newly painted house, if the doors and windows are kept close, is
consequently found to be very unfit for respiration. In many countries,
particularly where there are burning mountains, carbonic acid is given
off from the ground, and it collects in every hollow or cave, in
consequence of being much heavier than the air. There is a cave in Italy,
called the Dog's Grotto, because a dog on entering it is instantly
suffocated, though a man may walk in without injury. The cause is, that
the cave is filled up by carbonic acid to about four feet deep; a dog, or
any animal that holds its head lower than that height, breathes carbonic
acid and is choked, but a man breathes the pure air which is above it,
and escapes. In deep dry wells which have been neglected, carbonic acid
accumulates, and workmen who go down to clean the pit are sometimes
suffocated. In such cases a candle should first be let down, and if it
burns, the air is fit to breathe. If the candle be extinguished, it is
unsafe for an individual to descend.
In the Island of Java, however, perhaps the most remarkable collection of
carbonic acid is to be found. On the summit of the highest mountain there
is a circular valley of considerable depth, and presenting to the eye a
spectacle combining the utmost beauty and horror. The sides of the valley
are clothed with the richest perennial verdure of the tropics; all the
plants which grow on that fine island are there found of surpassing
magnitude and beauty, but intermixed with the skeletons of tigers,
wolves, and men. There is no living animal. The greatest developement of
vegetable life goes hand in hand with absolute destruction to all animal
existence. The natives call this place _the Valley of Death_. It is the
crater of an extinct volcano. From its bottom issue perpetually watery
vapour and carbonic acid, the elements which clothe its sides with
vegetable riches; but the whole being an invisible lake of carbonic acid,
proves instant destruction to the unwary animal that passes over its
brink. Some deserters from an English regiment concealed themselves in
it, and their bodies, seen through the transparent but deadly gas by
which they were surrounded, verified a fact which had been previously
suspected to be a fable of the natives.
In the fermentation of corn, for making malt liquors or ardent spirits, a
large quantity of carbonic acid is generated, and workmen who heedlessly
descend into the vats to cleanse them, are very often suffocated. The
trial by a lighted candle should never in such cases be omitted. In the
burning of lime there is a very large proportion of carbonic acid set
free; and poor persons who are tempted to sleep on the platform of a
lime-kiln for the sake of the warmth it affords, are sometimes suffocated
by the vitiated air they breathe.
The air, so far as regards its influence on health, is modified in a very
important manner by causes which are not so positively known and measured
as those we have hitherto examined. The spreading of odours through the
air, whether they be the "spicy gales of Araby the blest," or the more
unwelcome indications of putrescent matter, takes place by means of
quantities of substances so small as to defy the powers of detection we
possess. Many diseases, it is well established, arise from the formation
and diffusion through the air of peculiar poisons in amazingly small
quantity. Thus ague is produced by a specific poison generated in
marshes. These poisons resemble other ordinary poisons, inasmuch as we
can decompose them, and thus destroy their power. The chemical substance
chlorine decomposes almost every vegetable or animal material that it
touches. Thus it destroys all colours, and is hence of the greatest use
in bleaching; it also destroys all atmospheric poisons, and,
consequently, in hospitals and in private houses it is used to disinfect
or prevent the spreading of disease, by decomposing the material which
conveys it through the air.
For change of air we therefore, with reason, go to the country when we
can; but whether to the sea side or to the interior, to Enniskerry or
Kingstown, is not dependent on the nature of the air. Wherever the
invalid finds most amusement, and agreeable occupation which does not
fatigue; wherever the beauty of scenery, and the society of those to whom
the heart is bound in ties of mutual esteem and love, present to the mind
of one harassed by intense exertion of thought, or broken down by disease
of body, a relief in admiration of the wisdom and goodness of his
Creator, and in sympathy and kindliness towards his fellow men, the
atmosphere is clearest; the bracing, enlivening influence of the pure
country air is the most sensible, and the mind and body are most
effectually restored to the condition of perfect health.
IRELAND FOR EVER! AND KILMAINHAM TO THE DEVIL!--Mr Egan, better known as
"Bully Egan," held the chairmanship of Kilmainham at the time that the
government were using their utmost endeavours to pass the Act of Union,
and, of course, expected to be deprived of his office if he should oppose
it. However, when the time for the division had arrived, his love of
country preponderating over his love of self, he voted against the
measure, exultingly exclaiming, "Ireland for ever! and Kilmainham to the
devil!"