Evening star. [volume] (Washington, D.C.) 1854-1972, 1916-05-07

flter-bed Investigations are fraught
with live interest.
1T has been conclusively proved that
hundreds of millions of nematodes in
habit the filter sands in addition to
rhodifer, protoZa and other minute mi
cro-orga nisms already known to be
there. Each of these organisms is ex-
cretlng material. the soluble portion of
which must pass into the citys drink
ing water unless il is precipitated dur
ing its passage through fumes and de-
livery pipes.
1t is thought highly probable that
this organic matter is the basis of diff
ferences in taste in drinking water not
due to chemical variation, and that the
physiological effect produced by
change of drinking water. baff1ing to
the understanding of physicians. may
also be traced to the presence of for
eigu organic substances.
Excreta has its own peculiar char
acter. and that of any given species
must be different from that of any
other. Though differences between eX-
creta might be slight in organisms that
are similar TO each other, the differ
ences among organisms of different FL
ter beds are great enough to cause wide
differences not only in the inSoluble
parts. but in the soluble parts as well.
Such soluble parts as pass INTO the
drinking water must play their role in
Imparting to the water its flavor and
other qualities.
Persons even now sense a difference
in taste in the water Of different cities,
and il is not too fnespun to say that
the future Hill see connoisseurs of
drinking water like the present day
tasters of wine and tea. and that along
with the chemical and meteorological
tests. which are now so efficiently made
OF filter water. there will be an at
tempt to determine the nature Of the
substances which. it seems probable.
are the source of the difference in
flavor Of different city waters.
''I is beyond the imagination of the
scientist of todar to vision the relation
between this micro-organism and other
soil constituents" asserts Dr. Cobb.
who knows more about nematodes than
any man living. and who distinguishes
Tylenchulus devestatriN from des-
nosocolox with as little difficulty as
the ordinary person tells mouse from
an elephant. There are hundreds of
thousands Of undiscovered species of
nemas whose part IN the economy of
the soil IS scarcely seused
Hundreds of investiga tors will hav
lived and died before any visible i'm
preston is made upon this huge group.
and II is early to prosnosticate in any
definite way what the future holds in
The way OF applying these myriad or
ganisms to practical uses OF mankind.
Yet even the slight inroad which we
have made into this new science hints
at limitless possibilities.
Parasitic nematodes destroy crops
to the extent of millions of dollars
damage yearly" continued DIR. Cobb,
and il is believed that II torn condi-
ton of roots. which does not neces-
sarily destroy the plant but which i'm
pairs it's vigor and detracts from max
imum productivity. is caused by the ac-
ton of plant uematodes The gall
worm. which infests several hundred
different species Of plants. most Of
them cultivated crops. is a species of
nema The onion and other dubious
crops OF Europe are attacked by
nematode which frequently destroys
the entire crop. The nematode has also
blocked the way to the introduction
Of the dasheen, dubious plant of the