The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1874-02-27
[For the Dispatch.l
James River eSater-Wiaat Is the best
Means Of Clearing it?

means OIL Clearing lGs
As an addendum to the communication on
"Filtering Reservoirs" we state that one of
the late proprietors of the papermil in
Manchester, Dir. Ed. t. Robinson, says that
an attempt was made by The company to pro-
cure clear water from the river, for the
manufacture OF paper, by means OF litter
beds. The attempt was unsuccessful. IL
was found that the water could not 6e made
sufficiently clear, and also that in short
time the beds became so much o5structed
by the clay deposit that the water would
not pass. Let this statement be preserved
among the papers Of the city's Water Com
mittee.
In this city mode Of clearing muddy
river-water is in partial use, which, for sim
plcity, efficiency, and economy, IS perfcct
success. That there is high authority for
this usage. and that it is neither novel nor pc.
culiar to Richmond, will appear from the
following quotations :" Waters which wash
cliffs of clay become saturated with impalpa-
BILE material, which they almost wholly re.
fuse to shed by any mechanical action. Such
water, it is found, may be purified By adding
to it few grains of alum to the gallon. The
alum is decomposed, and its ingredients fall
in insouble precipitates, carrying with them
the alumina and other impurities which dis
color the appleton.
"In some semi -barbarous countries water
is cleared by rubbing the inside of the
earthcn vessel in which The water is GEN.
famed with some kind Of seed, the albumen
and casscine of which clear or fine the water.
The process is partially mechanical one,
but is aided by chemical influences. In In
dia, clearing-nutS (tne seed Of stIychnos pa
tatorumI: in EgyDt, almonds; in Nubla,
beans, haricots, and castor seeds, are used
for this purpose. Alum
is popularly used to clear muddy water.
Two or three grains are sufficient for quart
of water."-Peresra.
an. DArcet, after describing the above
and the common method OF filtration by Jtl-
tering- g-stones, next details a plan which he
found more successful in clarifying Nile
water. 1t consists in the introduction of a
solution of alum, or Of the powder itself, in
the proportion Of a quarter, or even half, q
grain to a quart of water. This means bad
already been used with success by the father
of Nj. D'Arcet in purifying the water Of the
Seine at Paris. The Chinese (of course) had
long been in the practice Of Clarifying the
turbid water Of their rivers by stirring the
fluid which has been drawn with a bamboo
cane, into the hollow joint at the end OF
which a piece Of alum bad been intro
duced."- -Ann. d dHygieae, quoted By Bel.
"Jeunet adds one, gramme of alum to ten
Iitres Of turbid water, and In few minutes
it is fit for llse."- Journal Applied Chem.
tstry. 5,,., ~,
The addition of alum never fails to render
our muddy iriyer-water tTansparently clear;
and no taste IL impaired by it to the water
ii too large an excess is avoided indeed,
if exa city the eright quantity Is used there Is
no a III n In the cleared wafer Alum is COM
posed OF sulphurie acid, alumina, and ammo.
min rye use popular terms) In our,fiver-
water are small quantities of lime and or.
gunic matt VI dn all probability mixed with
the clay. TIE sulphuric acid in the alum
parts company .snd Gnttes with the 1ime, and