The Camden chronicle. (Camden, Tenn.) 1890-current, 1910-06-24

which root themselves in the soil at
the bottom and sides of the pool, but
those which float about freely both
on the surface and in the body of the
water Many of the latter class, and
some of the most effective, are nil
croscopic-so small that they cannot
be seen by the naked eye But what
they lack in size they make up in
numbers. Others form green scum
on the surface of the water, while
others again, like duckweed, cluster
together and form a green mat, each
plant sending down it's tiny roots into
the water, absorbing the soluble de-
caying matter and using it to build
up clean vegetable tissue
1t is chiefly through the agency of
plant life that offensive soluble mat
ter is gradually removed and con-
verified into vegetable tissue and oxy-
gen. And here it may be we'll to
note a singular but very prevalent
fallacy in regard to the green scum
which is so often seen on filthy pools.
1t is no uncommon thing to hear the
scum blamed for the filth, the owner
of the pond being urged to remove it
and ''let daylight into the water"
Now, daylight is a very good thing,
and it acts as most efficient cleanser,
but it does so most thoroughly when
it acts through the medium of active
plant growth. Falling on the green
plants which form the scum, sunlight
accomplishes many times the puri-
flying work that it can do when it
merely passes through the water and
is absorbed by the black mud at the
bottom. In all such cases aquatic
plants of every kind, from the often
sive green scum to the beautiful
water lily, grow and flourish because
the water is so filthy that it affords
them the nourishment that they re-
quire. The filthy water is the cause
of the plant growth; the plant growth
is not the cause of the filthy water.
1t is natures effort to utilize matter
which otherwise would be not only
useless but deleterious. And remem-
Der that the moist dirt or filth is not
essentially evil. 1t is only matter in
the wrong place Put it in the right
place and it will do good work, build
ing up most effectively delicious vege-
tables, like celery, asparagus and
fruits like Strawberries and raspber-
ries.
In this connection, a point which
deserves special attention is the fact
that the oxygen given off by plants
under the influence of sunlight is in
a peculiar condition known as the
nascent state. Oxygen in this condi-
ton is much more active than ordin-
airy oxygen, This is we'll shown by
its bleaching power when fabrics are
spread on a fresh grass plot in bright
sunlight. Every washerwoman knows
that an hours sunshine aided by
good grass plot will do more in the
way of bleaching linen than half
days sunshine when the clothes are
hung on the line. Now, as fast as
the oxygen is liberated by the plant
it is dissolved in the water and oxi-
dies or destroys most of the organic
impurities present.
A very important characteristic of
this dissolved oxygen is that it seems
to be destructive to bacteria and mi
crobes. Whether this result is due
to the removal of the food of these
organisms or to a positive deleterious
action upon them may be a debatable
question; the probability is that it
tn c.
is this action, however, that it has
been claimed that if a quantity of
sewage is poured into a stream of suf-
tlcient size it will all disappear in the
course of a two or three-mile flow.
Most aquatic insect larvae subsist
upon the microscopic plants which
they find in the water they inhabit,
though some of them, such as those
of the dragon fly, are fiercely carniv-
orous. They tend by the decay of
their dead bodies to render the water
impure, and where man exercises any
control they should be kept down as
far as possible.
The best assistants in this direction
are small fish. Large fish are utterly
worthless for this purpose, as they
are not sufficiently active and they
prefer larger game than small larvae.
Indeed, the food of most of the large
fish consists chiefly of small fish
sometimes those of their own species.
A few dozen minnows from one to
three inches in length will extermin-
ate all the mosquito larvae in a good
sized pond and will do little toward
defiling the water. But a dozen perch
or two or three pckerel will soon
eat up the minnows and allow the