strengthen our powers of resistance by a
reasonable amount of exercise, the breath-
ing of fresh air, attention to suitable cloth-
ing, heedfulness of any organic w^eakness,
and everything adapted to give us strength
and powers of endurance.
Impure Air.
The air which we breathe is rarely quite
pure, and is often very impure. This is
especially the case in city life and within
our houses . Pure air is only to be found in
the open country, the mountains, or at the
sea-side. In addition to its normal oxygen
and nitrogen, many other gases make their
way into it, some of them, being very un-
healthful. There are also solid particles of
"dust," of a great variety of materials,
animal, vegetable, or mineral, many of
them more or less harmful. The worst of
them are the floating bacteria, living germs
of disease, which inhabit air and water
alike ; the great majority of these are harm-
less, some of them are deadly in their effects.
Of the impure gases in the air, some of
the worst are of our own production. We
are constantly breathing out matter which
is poisonous to the system if breathed in
again. This is largely carbon dioxide (or
carbonic acid gas), with small quantities of
organic poisons, the waste of the system.
We can easily understand how it is that
pure air becomes poisoned by respiration,
the specially dangerous products being the
carbon dioxide and the organic matters. The
total amount of carbon dioxide breathed
out in an hour is about 6 cubic feet. While
this is an injurious gas, it is probable that
THE FAMILY DOCTOR
97
the bad effects of breathing respired air are
more due to the poisonous organic matter,
as it is found that while an artificial atmos-
phere containing i part of carbon dioxide
MISPLACED PIPE.
in IOC of air causes but little discom-
fort when breathed, yet if an already
respired air containing only i part of carbon
dioxide in i,ooo of air is breathed much
discomfort is experienced. This organic poi-
son is probably composed partly of an or-
ganic vapor from the luns:s, and partly of solid
matter from the lining of the mouth and air
passages. It is difficult to find out the
exact quantity of organic matter present,
but it varies exactly in proportion to the
quantity of carbon dioxide, and the amount
of this in respired air is therefore taken as
the standard of impurity.
The Air from Sewage and Sewers. —
This is found to contain a great diminution
of the oxygen, a large increase of the carbon
dioxide, and many other gases, such as sul-
phureted h3^drogen, sulphide of ammonium,
marsh-gas, etc. A more harmful constitu-
ent is found In the numerous germs present,
which are probably thrown into the air of
the sewer by the bursting of bubbles on the
surface of the putrefying sewage.
The air from churchyards contains car-
bon dioxide in excessive amount, various
vapors of ammonia, offensive and putrid
gases, and many germs.
Air polluted by Trades. — These impuri-
ties depend, of course, on the nature of the
trade. We may have hydrochloric acid,
sulphur dioxide, sulphurous acid, ammonia,
and sulphureted hydrogen from chemical
36
Page 242
Presented as published in 1901. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
strengthen our powers of resistance by a reasonable amount of exercise, the breathing of fresh air, attention to suitable clothing, heedfulness of any organic weakness, and everything adapted to give us strength and powers of endurance.
Impure Air.
The air which we breathe is rarely quite pure, and is often very impure. This is especially the case in city life and within our houses . Pure air is only to be found in the open country, the mountains, or at the sea-side. In addition to its normal oxygen and nitrogen, many other gases make their way into it, some of them, being very unhealthful. There are also solid particles of "dust," of a great variety of materials, animal, vegetable, or mineral, many of them more or less harmful. The worst of them are the floating bacteria, living germs of disease, which inhabit air and water alike ; the great majority of these are harmless, some of them are deadly in their effects.
Of the impure gases in the air, some of the worst are of our own production. We are constantly breathing out matter which is poisonous to the system if breathed in again. This is largely carbon dioxide (or carbonic acid gas), with small quantities of organic poisons, the waste of the system.
We can easily understand how it is that pure air becomes poisoned by respiration, the specially dangerous products being the carbon dioxide and the organic matters. The total amount of carbon dioxide breathed out in an hour is about 6 cubic feet. While this is an injurious gas, it is probable that
the bad effects of breathing respired air are more due to the poisonous organic matter, as it is found that while an artificial atmosphere containing i part of carbon dioxide
MISPLACED PIPE.
in IOC of air causes but little discomfort when breathed, yet if an already respired air containing only i part of carbon dioxide in i,ooo of air is breathed much discomfort is experienced. This organic poison is probably composed partly of an organic vapor from the lungs, and partly of solid matter from the lining of the mouth and air passages. It is difficult to find out the exact quantity of organic matter present, but it varies exactly in proportion to the quantity of carbon dioxide, and the amount of this in respired air is therefore taken as the standard of impurity.
The Air from Sewage and Sewers. — This is found to contain a great diminution of the oxygen, a large increase of the carbon dioxide, and many other gases, such as sulphureted hydrogen, sulphide of ammonium, marsh-gas, etc. A more harmful constituent is found In the numerous germs present, which are probably thrown into the air of the sewer by the bursting of bubbles on the surface of the putrefying sewage.
The air from churchyards contains carbon dioxide in excessive amount, various vapors of ammonia, offensive and putrid gases, and many germs.
Air polluted by Trades. — These impurities depend, of course, on the nature of the trade. We may have hydrochloric acid, sulphur dioxide, sulphurous acid, ammonia, and sulphureted hydrogen from chemical