The Republican. [volume] (Oakland, Md.) 1877-current, 1892-05-20
PURE WATER.
Il Il Hard to Obtain. but Nature Furnishes
Much of 1t.

Il Is Hard to Obtain. but Nature Furnishes
Much of 1t.
Impure streams that flow through
| rich agricultural and densely populated
regions are apparently purified by dilu-
ton from springs along the banks and
the infiowing smaller streams of less
impure water. The by-products of
| chemical factories that are thrown into
streams, and which are neither removed
| by chemical action nor by sedimentation,
are frequently so diluted in few miles
| flow that the water becomes harmless,
| although at the factories it may be a
| strong antiseptic. Streams become puri-
| fled to the greatest extent, however, by
| process of sedimentation, which, in its
| origin, is largely influenced by chemical
action. This takes place as the velocity
of the current diminishes. when much
| of the insoluble matter subsidies, re-
| moving with 1t organic matter that
would remain in suspension or solution
for many days. Along slowly running
streams can be seen in summer organic
accumulations on stones laid down by
| sedimentation. A careful study of the
various natural processes of publication
| has led DIR. Percy +. Frankland. of En-
| gland, To the conclusion that not only
| is sedimentation the principal cause of
| the natural removal of decaying organic
matter from river water, but that it is
| also the principal cause of the partial
| disappearance of germs The latter is
of great hygienic Importance in both
n1 49, So g
| water.
| But nature does not completely re-
| move organic matter and micro-organ-
isms from river water. The distance re-
quired for reasonable separation of
the former in our American streams is
generally not more than fifteen or
twenty miles. and often much less. The
Hudson river. which receives the sewage
of Troy. becomes reasonably free of it's
organic matter in the six or eight miles
flow to the city of Albany. But owing
to the small size of some of the English
streams. like the rivers Severn, Tee and
Wear, and the great population ON their
banks. the waters remain unfit for use
many miles below the points of contain
nation, and the royal commissioners
| concluded that there is not a river in all
England sufficiently long to free itself
through natural agencies of even
moderate amount of sewage. The self
publication of water in streams is no
guarantee that it is Wholesome at any
distance below the place where it is GER
tainly contaminated with products of
the human body, for although the or
ganic matter and even the germs may
be largely removed it is unsafe to drink
water for any length of time that con-
tains even few infectious bacteria
When river water has once been pol
luted with excrementitious washing
from diseased patients it should never
be used directly or from city water
works without due consideration of it's
nature and the possibility of its produc-
ing disease.
Nature also purifies water to con-
siderable extent in freezing, and the
product deserves our attention, for there
is rapidly increasing demand for ice
in the United States, where we are al
ready cutting some twenty-five million
tons annually. Those who frequently
examined ice and have followed Tyn-
dali, Cramer, Leone, Fraenkel, Engel-
mann, Pengra, Prudden and others in
their Investigations know that water
is only partially purified in freezing.
The freezing process removed for Pen
gra only from twenty to fifty per cent.
of the organic matter, forty per cent of
the organic salts. and about ninety per
cent. of the micro-organisms. The
diminution of bacteria in water in freez-
ing is owing largely to their destruc-
ton, instead of expulsion. But some
species of bacteria have great power of
withstanding cold, and the bacillus of
typhoid fever has been found in ice sew
eral months after its formation: and
there are many other classes of germs
that cannot be destroyed by freezing
alone When such impure ice is melted
the living germs regain their activity,
and. If pathogcnic, are capable of pro
ducing disease. Impure snow water is
also sometimes detrimental to health.
Some years ago DR.. Charles Smart, OF
the United States army, traced the
cause of a mountain fever to the melt
ing snow of the Rocky mountain
streams and inferred that the germs of
this typho-malarial fever were brought
down from the atmosphere by snow, re-
manned frozen during winter, and then
passed into the streams in an active
condition when the snow melted in
May, June and July. 1t is frequently
the case that impure ice is the agent of
transmitting typhoid and other fevers.
Engineering Magazine.
EASAIONS In LEMEI QX