DISEASE GERMS
=197. Catching diseases.=--Our body may get out of order like a
machine. Some parts of it may be cut, or broken, or worn out, or hurt
in other ways. Then we are sick until it is made whole again. Sickness
always means that a part of the body is out of order.
Some kinds of sickness are like a fire. A small bit of something from
a sick person may start a sickness in us, just as a spark may set a
house on fire. Then we may give the sickness to others, just as a fire
may spread to other houses. If a person has measles, we may catch the
measles if we go near him; but if a person has a toothache, we cannot
catch the toothache from him. So we may catch some kinds of diseases,
but we cannot catch other kinds.
=198. Bacteria and germs.=--Every kind of catching sickness is caused
by tiny living things growing in our flesh and blood. Some of them are
tiny animals. Most of them are plants, and are called _bacteria_ or
_microbes_. A common name for all of them is _germs_.
The word germ means nearly the same as the word seed. Bacteria are so
small that we cannot see them unless we look at them through a strong
microscope. Then they look like little dots and lines (p. 54). A
million of them could lie on a pin point; but if they have a chance,
they may grow in numbers, so that in two days they would fill a pint
measure.
Very many kinds of bacteria and other germs are found nearly
everywhere. They are in the soil and in water, and some float in the
air as dust. When they fall on dead things, they cause _decay_ or
_rotting_. When we can fruit, we kill the germs by boiling the fruit
and the cans. Then we close the cans tightly so that no new germs can
get into them. The fruit will then keep fresh for years.
Decay is nearly always a good thing, for by it dead bodies and waste
substances are destroyed and given back to the ground, where plants
feed upon them. Many plants would not grow if they could not feed upon
decaying things. So most bacteria and other germs are useful to us.
But some kinds of germs will grow only in our bodies, and these kinds
are the cause of most of our sickness.
=199. Germs of sickness.=--We catch a sickness by taking a few of the
germs of the sickness into our flesh. There they grow quickly, like
weed seeds in the ground, and form crops of new germs within a few
hours. After a few days the germs become millions in number, and crowd
the cells of our flesh, just as weeds may crowd a potato plant (p. 54).
Disease germs in the body also form poisons, just as some weeds in a
field form poisons. The poisons make us sick, just as if we had
swallowed the leaves of a poisonous weed.
=200. Fever.=--If a sickness is caused by disease germs, the body is
nearly always too warm. Then we say that the sick person has a
_fever_. Almost the only cause for a fever is disease germs growing in
the body. We can make a person have any kind of fever by planting a
few of the germs of the fever in the right part of his body.
We are made sick by the germs of fevers more often than by all other
causes put together. Here is a list of common diseases caused by fever
germs:--colds and sore throats, most stomach aches, blood poisoning in
wounds, boils and pimples, tuberculosis, whooping cough, measles,
chicken pox, diphtheria, scarlet fever, typhoid fever, smallpox, and
malaria.
Which of these kinds of sickness have you had? What sickness have you
had besides these?
=201. Sickness and Dirt.=--Disease germs leave the body of a sick person
in three ways: first, through the skin, second, through the kidneys and
intestines, and third, through the nose and throat. In these same ways
our body gives off its waste matters. If we did not take anything from
another person's body into our own body we should not catch fevers.
Whatever a feverish person soils may contain disease germs. When a
person has only a slight fever he often keeps at work, and then he may
scatter disease germs wherever he goes. So disease germs are likely to
be found wherever there is dirt or filth. Cleanliness means good
health as well as good looks.
=202. Disease germs in the skin.=--Disease germs may often be found in
sores and pimples on the skin, but they will not leave anybody's flesh
and blood through sound and healthy skin. If our skin is smooth and
fair, there will be few disease germs on it unless we rub against
something dirty. A dirty skin nearly always contains disease germs.
Washing and bathing our body will take disease germs from our skin and
help us to keep well.
=203. Disease germs in slops.=--A great many disease germs leave the
body through the intestine and kidneys, and may be found in the slops
and waste water of our houses. Slops are dangerous to health, for they
may run into a well, or spring, or river, and so carry disease germs
into our drinking water (p. 27). Also, house flies may light on the
pails or puddles and carry the germs to our food. In these ways we
catch typhoid fever, stomach aches, and other diseases of the
intestines. All slops and waste matters from the body should be put
where they cannot reach our drinking water, and where flies cannot
crawl over them (p. 80).
=204. Disease germs from the nose and throat.=--If a person is sick with
a fever, many of the germs are likely to be found in his nose and
throat. Thousands of them are driven out with every drop of saliva and
phlegm when he blows his nose, or spits, coughs, or sneezes, or talks.
If he puts anything into his mouth, it will be covered with germs. More
diseases are spread from the nose and mouth than in any other way, for
we are always doing something to spread bits of saliva and phlegm.
=205. Spitting.=--Colds and consumption and other forms of sickness
are often spread by sick persons spitting on the floor or pavement.
The germs become dried and are blown away as dust. For this reason
dust from the streets of cities and in crowded halls is often the
cause of sickness. In many places spitting on a floor or pavement is
strictly forbidden by law.
=206. Putting things in the mouth.=--Many persons have the habit of
sucking their fingers, or of touching a pencil to the tongue when they
write or think, or of wetting their fingers with their lips when they
turn the leaves of a book. In all these ways we may give a disease to
others or may take a disease from some one else.
=207. Public drinking cup.=--When you touch your lips to a cup, you
leave some saliva and cells from your mouth on the cup. If a cup is
used by a number of persons, some one is almost sure to leave germs of
sickness on it, and others are likely to take them into their own
mouths when they drink. So a public drinking cup is a dangerous thing.
Each school child should have his own cup. Public drinking fountains
should be so made that we may drink by putting our lips to a stream of
running water.
[Illustration: =A safe drinking fountain.=
A stream of water gushes up from the middle of the cup.]
[Illustration: =An unsafe drinking place.=
Photograph taken in the basement of a schoolhouse.]
=208. Sweeping.=--Dusty air in a room is dangerous to health, for
disease germs are likely to be found in it. We can get rid of dust by
keeping our floors swept clean. After sweeping we should wipe the dust
from the tables and furniture. A feather duster or dry cloth will only
stir up the dust and make it float in the air again. We should use
either a damp cloth, or a dry duster made of tufts of wool, so that
the dust will stick to the duster.
[Illustration: =House fly, magnified.=
The hairs on its body and legs catch dirt and disease germs.]
=209. Foul air.=--If we live in a closed room, the air soon becomes
foul and dusty, and is likely to have disease germs in it. Foul air is
one of the greatest of the causes of sickness. We should change the
air of a room often so as to keep it fresh and free from dust and
disease germs (pp. 65-67).
=210. House flies.=--House flies come from garbage heaps and filth of
all sorts. So they carry disease germs on their bodies. They light on
our food and on our faces, and so they often make us sick. They are
often the cause of typhoid fever, stomach aches, and stomach sickness
in babies.
[Illustration: =Life history of house flies.=]
Flies are hatched in manure piles and garbage heaps. At first they
look like white worms, and are called _maggots_. Every maggot is a
young fly. We can get rid of flies by cleaning up every garbage heap
and manure pile.
[Illustration: =Young mosquitoes hanging head downward in water.=]
=211. Mosquitoes.=--Mosquitoes carry malaria and yellow fever from
sick persons to the well. If there were no mosquitoes, there would be
no malaria or yellow fever.
Mosquitoes are hatched in water, and the young are called _wigglers_.
We may often see them in rain barrels. We may get rid of mosquitoes by
emptying all rain barrels and pails and cans of dirty water, at least
once a week, and by drying up swamps and marshes.
WHAT WE HAVE LEARNED
1. We catch a fever by taking disease germs into the body.
2. Disease germs cannot be seen without a strong microscope.
3. The germs may be found in dust and dirt.
4. Slops from our houses are often full of the germs.
5. You may take germs into your body by putting pencils and other
things into your mouth, and by drinking from a public
drinking cup.
6. Spitting on the floor or pavement may scatter disease germs.
7. House flies and mosquitoes often spread diseases.