Evening star. [volume] (Washington, D.C.) 1854-1972, 1894-02-06

wholesome water may be obtained. Brook
Ign. Long Island is supplied in part by sub
soil water piped from a clean filtering area
at some distance from the city. At isolated
country houses the dangerous characte- OF
the shallow we'll arises from the proximity
of cesspools, pits garbage heaps and man
ured ground; and not unfrequently the
handsome trees that throw grateful shade
over the cool waters of the well form chan
nels OF entry for uniiltered seepage alonS
the course of their roots. The distinguished
bacteriologist, Prof. Koch. attributes any
EMBELLISHMENTS of such wells TO unfiltered
inflow from the surface. but whether the
contamination is from unfiltered inflow or
from the inefiiciency of the subsOil as .
hitter, the facts remain that such waters are
found by the chemist To contain much or
Sahlc matter, vegetable and animal. and bv
MEDICAL observers to be associated with the
fevers.
The deep or subterranean waters are
those mat falling ON high ground sink into
broken edges OF some porous stratum which
underhes the clay beds of the bottom lands
1he waters percOlate through and along
me porous stratum underneath the imper-
meable clay which supports the SubSoil
water When tapped 10y digging or BORING
tney are the waters of our deep wells origi-
haIiy pure but often valuelcss for domestic
or manufacturing purposes on account of
tne large amount of mineral salts which
they have dissolved in their subterranean
course. If the perViouS LAYER be. one of sand
anu gravel the water may Toe as pure a
distilled water. The discovery of Slcn
water 300 feet below the surface of the civ
OF Memphis, Tenn, solved the water cues
ton for that city at a time when its citi-
Zens We're debating whether the million
dollars which they could raise for a Nyats,
supply should Toe expended in bringing in
the cIay-laden waters Of Wolfe river or the
SeWaSe-poluted waters of the NiSsissipni
me thorough filtration to which this deep
lying water is subjected in its subterrauean
course freed it from all germs. whether OF
malaria or of typhoid"
DR.. Smart then gave some interesting
pfactlcal Illustrations of the methods fol
lowed by chemists in testing waters to dis
cover the presence of various kinds of i'm
purities
Processes Of Publication.
Nature purifies," he said. water by
three processes: BY evaporation with slIbse-
quent condensation, by filtration and by
sedimentation
Inc flrst method is perfect as a purify
ing process but it can be utilized by man
only on the small scale. Distilation has
frequently been employed by army medical
ohcers particularly in times of epidemic
Fort Brown owes the suppression of The
prevalence of malarial fevers to the 1Isf OF
distilled water But TO provide a water
assuredIy tree from the germs of diSeaS,
tnere Is no need TO distill. Boiling the water
gives ample security.
FILTRATION as conducted hv nat,ra IN tn,
porous strata of the earth Yields A Sterile.
Water-that is, water perfectly free from
SerhS-but the area Of our artificial filters
Is necessarily small that to obtain
enough OF water from them We must run
the water through rapidly. with the. result
OF getting a clear water that may nor h.
sterile one Nevertheless. artificial hitter
beds are largely used in Europe for m.
supply OF cities because. although the fItra-
ton may not be perfect il improves tb@
water materially. The water supply of th,.
city OF London is filtered water
w - in this city Of Washington. are NOR
interested IN sediinentaUOn than in fltr9-
tilh, because il is oStensbly by this mean
mat our Potomac water is treated During
standardization the particles of SUSPENDED
matters fall to the bottom carr-I-ina Win
them to the Shiny layer which they form
most of the bacterial and other Organisms
but time IS required TO accomplish this
and during that time the living organ
lSmS that are present i'm the wafer atrarl
and destroy the dead organic matter that
is dissolved in 1t, so that by the time
surface water is clear it is often purer than
the original rainfall. We can put more
faith in the whClesomeness of a wate;
clear by seiimentatiOn Than in that of =
water clear By filtration.
NnsiingtoH's Water supply and Ty-
phoid Fever.
The greater the care taken in the purif-
cation OF Il citys water supply the less
is the death rate of that city from malarial
and typhoid fevels. Brooklyn has an aver
age annual death rate from typhoid of IL
IN every 100000 of its population, New York
20, London -. baltimore 40 Boston h.. Gin
cinnau Gi. Philadelphia CG. Chicago 90. and
asnlnStOn, according TO Dr. BILLINGS re-
cent census WORK. 40. W., do not have This
high rate because our sewerage system -
detective, Tor Baltimore has no sewerage
system. nor because our houses are over
crowded and Unvehtllated. back yards filthy
anu UNFRAMED and streets narrow and un-
clean. 40. "" have il because the germs
OF The disease are distributed along wf-h
the clay PARTICLES Of the Potomac water.
The inflow of sewage into the Potomac
river above The Great Fails IL small but
there is enough Of 1t TO give Us more
typhoid fever than is found in Baltimore
New Orleans and other cities that lack many
of our sanitary adVa9 tages. Now let us
examine in what manner our water supply
is purihed.
AT the present time We have Il single
reservoir which, although ii holds a four
days supply, does not permit of CORE
spending sedimentatIon, ami The reason is
th!s: Ilc Reservoir is divided by I CrGSS
dam into TWO. parts. an upper Or receiving
and seiim N Ting basin aud a lower or dis
trlbutins basin, the Two being connected 10y
a gateway about III" middle IF the dam.
Now The pun on the water by thu outflow
To the city Is so great that a current ~ eSI4b-
li.sGed through the safe between the CON
duit which brings the water in and the
mains which carry II away. The water
pIsSeS almost directly from the one 10 jht
other and the value OF the reservoir as a
$. lilnsuting basin Is practically lost. II
Tins cross dam were lowered and the gate
closed 50 that cCmmUuic;st ton between the
two divisions could be effected only by Il
flow over tn top % the dam the quality
OF the water would be- much improved FCl
several years past Col. Elliot. IN charg- Il
the water supply. has asked Tor an apDro-
priatiCn of $lL5.trn To enable him to 10 this
This small expenditure would permit the
upper division 20 act as u catch basin for
the clay Particles and in catching the clay
il would catch also the more dangerous
impurities.
"A great Improvement l. at present IN
progress under the superintendent of Col.
Elliot. Ii IS the reclamation OF the Dcta-
ca Ria basin. which was used a. a receiving
basin up to lS>s. when the increasing inflow
of sewage from its drainage area led 10 its
disuse. The foul water OF the creeks that
have their natural outlet into this basin vii,
be turned aside and led TO the Potomac
slope 10y a tunnel through the Delacarlia
hill. No water will then enter the basin
but that which arrives from Great Falls by
way of the conduit. The form and sheltered
position OF the basin. surrounded as il IS 10y
high and well-wooded banks. viii give every
facility for sedimentation and natural puri-
fication to the lT5.tSS,0OJ gallons supply
which il is capable of containing.
with Sedimentation in this basin and A
flow over in the reservoir We would seem
to have satisfactory provision for the puri-
fication OF our water supply: but the ex-
posed situation OF the distributing reservoir
renders more than this imperatively neces-
sary. Its area is 50 great as compared with