The sun., 1891-10-04

sediment remains pure and tatntl06S Just be-
cause 1t has FREQ access to the oxygen Of the
atmosphere. The millions OF minute plants
contained in small quantity Of this sediment
thus are enabled to live and grow. and finally
die natural DEATH They are not strangled
or starved to death as they were In the closed
bottle. While they are living they have to
thermore. they serve to Keep the water pure
Ro ass
ly used IN building up their tissues;
tiai It is to have reservoirs. tanks. and other
bodies Of water that contain much organic
fs % Ged psnss h hR M ss
from the water into the various constituents
cells. and the air ia, needed to Keep the water
Hns Ss fsgoa 81 h SsSSs domestic
laIgs, cities. shopId have 9 rapid dow. and. Il
cipitous descents: or in case they, cannot how
so rapidly as 1t is possible to All them, the
q ths
and not near the top. Where the water Is
naDE Tsr psn It ss a. PSRaS being s.e 30
Keep 4, thoroughly aerated. and. therefore.
sob1es by ehes
leaves. These gl2bules OF oxygen may be
seen dQn0rlnR 10 the surface OF the leaves OF
almost any water weeds on q warm summer
S%yEhss SSayih sehoolboys and anglers call them Fair
Many persons imagine that water containing
vegetable nature, especially Il such organisms
in which case they. appear Chiefly as sediment
Such Is not the case. howeysr @ 81 soSrse thc
aa 81 tSo
principle found IN the decaying stems Of
end vSsh sash
has no bad smell being constantly aerated BY
tns Ssaf S he a.
tions beneath. and 1t IL used for domestic pur-
pGTfSss WS Sfewh y oaress plants in the croon
tey asyse oi eSe Ss % sab
Gs ped sans
from the decomposition Of animal bodies that
may have fallen into tho lake. ,.u.. .u.,
iyssetsbSIss bodies knSSp ss desnitds snd dis:
an and shapes assumed Iy these plants. small as
thSE are & is something tS wonder tks Ht; ..,d. ~,
long. are az cellular. aowerless plants. devoid
OF rootS which aabsorb nouris%hn1ent H % from the
hrSugh rss ths walls o. taer ss psr
stiles. form. Some are. so minute as to moro
than than taH the power Of the best MICROSCOPES.
extending as much as 2OO feet over their
marine ped, and with stems so strong and
q such utility as to be manufactured into han
dies for small tools and cutlery. The desmids
mna y ant sna sRhaSn Ssy as
able size. the form Of the individual plants
cannot be made out except under q good
micr9scope Theyhave the power Of motion
to limited degree meyInf sSw toEwssd
saracs 81 hs 1atsr formns soS 20 espe tae
cially when the water is subjected to strong
rays OF tho sun. In each case their motion
causes o slight upward current, y the water
be otherwise .quiet, causing dirt and other
ssgR With Ssm %os e bs. tS the sur
mains, being held 70 the I sSrisss | By @ sontast
Is another method BY which they help to
purify the water. In the cuts to 8. ak dfner-
ent kinds Of ,desmids common IN the Croton
water rs ilast.asea from nature highly
not much more highly deyeloped than the
same water. In all Of these plants the circula-
tlon OF the grapules 10 the protoplasm is qqte
evident This movement OF the very life
principle Of plants has been compared by some
blood IN the lower anlmals and In man.
Diatoms. which are ike the desmids, o group
OF algg very low In the scale Of development
are quite numerous In the Croton water. and
SO far as Ind dividual plants are concerned. come
In greater abundance through the city water
pipes than any other plants. They are OF more
tptsr9st to the eSyersse perhaps
on their cell walls. These markings are not
always distinctly visible. until the plants have
been boiled ID splphurio acid 10 eat