Evening star. [volume] (Washington, D.C.) 1854-1972, 1880-10-09
THE WATER WE DRINK.
How to Test if-Causes of Water
Pollution - Analysis Of Potomac

How to Test if-CauSes of Water
Pollution - Analysis Of Potomac
Water.
In bis annual report to Engineer Commits
sioner -Twining the District chemist, Dr. De
Smedt, says: s'Thus far the water Of lis pumps
has been analysed with the following results:
Coed water, 76 pumps; still disable but in daa-
ger Of pollution, is; mineral, 5, a iron and l
sulphur; unfit for drinking purposes, 81. Pure
water strictly so called, Is not to be found In
nature. All water contains more or less impur-
tiles, and 1t rests with the analySist to deter
mine III water has the requisite Qualities to be
fn 81 as good potanle. water or ought
purposes. To form Judgment as to the char
acter of waters there must be microscopic
examination. and the amount OF organic mat
yer, me existence or non-eXistence OF the pro-
ducts OF the oxidation Of organic matter, such
as nltrates; the amount of chlorine, the
amounts and nature of the saline con-
tanned. The most important is the micro
scope examination. Mineral particles may af-
Iect nealtn On account OF their mechanical &C.
end s s or clay or me sand
stances may have more important effects as
Wnen suspended focal matter produces irrita-
tlon OF the whole elementary tfact. Living
things, such as the oya of Eutozoa, the men
atold worms and small leeches may
give rise to certain grave disorders. There are
however, numerous living creatures, both ami
special effect on health can be assigned, and
are important only as showing the presence O
organic Impurities. which serve as their food
as tnallcasing putrefaction. Water containing
bacteria or fungi, or sWarmtng with the lower
forms OF life, should be condemned All waters,
even the puraSt, contain some organic master,
ana the excess Is alone objected TO. The doctor
oescFloes the methods employed by him-.he
eStlmat10n OF the amount OF ammonia present
In the water, the amount of nitrates. chlortae
saline constituents, and degree OF hardness; and
under the head
CERTAIN RULES FOR JUDGEMENT
says If water yields merely traces OF album
lnolo ammonfa1 Ii may be called Organically pure
despite of .o5 parts OF free ammonia per million
Mheh tothis free ammonia is parts per mil
Ion noda IS added water begins to be suspicious.
per million or album1no1d ammonia begins to be
very suspicious, and even is parts per million
ought to be condemned as unfit for drinking
purposes. The average quantity OF nltrateS
and nitrites in the pump waters of the city is
from to 10 parts In 100000 but water con-
tanning 20 parts along with great quantity Of
chiorine he would consider as in danger OF pol
luton. In the presence OF oxygen the nitrogen
OF animal matter is Transformed in great part
into nitric and nitrous acids, and these
oy combining with the basic substances always
present IN polluted water are in their turn con-
verted into nitrates and n1trlteS. The change
Is most rapid and complete when polluted
water passes through aerated soil, but when
the soil is overloaded with organic matter or bY
some unknown causes the purifaction by oXt-
datton may be stopped. and hence the pollution
OF water. The average quantity of chlorine
contained In the pump water in this city is from
8 to 10 parts in 100000 parts Of water; is parts
would be properly presumed to have a bad
origin.
The analysis of Potomac water is as follows:
Appearance, somewhat turbld; vegetable and
mineral substances in suspension, Is parts in
100000; hardness, degrees; solid residue, Is;
organic matter and Volatile 0.04; free ammonia
slight traces; albuminoid ammonia and nItratps
and n1tr1teS, traces;mineral su MISUNDERSTANDING,
magnesium, potassium, sodium, aluminium,
silica, chlorine. carbonate acid and sulphuric
acld-traces; chlorine, .094; opinion, very good
water. A mere filtering makes this water
almost Organically pure.
Lieut. HOXie adds "This water is ordinarily
clear. 1t is only turbfd after storms on the
upper river"