The Saint Paul globe., 1900-04-15
Only january NAS Bad |RE WILL NOT Be HANGED|
RESULT OF EXAMINATIONS, OF CITY
WATER SUPPLY FOR SEW
ERAL MONTHS
SCIENCE TEACHERS SEARCH
Miss Margaret Tanning Reads a Pa
per on Organisms as OBJ
90 served in st. Paul City
Water.

i, Organisms in the st. Paul Water Sup
ply; Methods of Collection and Study
was the subject Of paper read yest2r-
day afternoon by Miss NJ G. Tanning, OF
this city, before a gathering of teachers Of
science at the state university. Miss Fan
ming is a member of the Central high
school faculty. Her paper yesterday was
illustrated by a map and chart, the tor
mer showing the location Of the various
lakes and streams from which st. Paul
draws her water supply, and the, latter
giving the results of her daily observa-
tons The paper was i'll part as follows:
During the last ten or twelve years
much attention has been paid to the
sources of the water supplies of the cit
les and towns in the United States, both
by boards of health and by individuals.
This study of plant life in the water is
particularly valuable because of TIE
knowledge 1t gives of the sanitary rela-
tions of these organisms to drinking wa
ter
THE water supply Of ST. Paul is drawn
from a region north of the city, which
contains about twenty-three lakes. These
lakes are coupled either by creeks or ca
nails constructed by the company The
highest lake is Lake Pleasant, which Is
1856 feet above the level of the Mssi ssippi
river. The slope is sufficient to drain tine
water into Lake Vadnais. From this point
it passes to the pumping station, where
it is forced into the mains and is di.t!ib-
uted to the various parts Of the city.
/ commenced my examination of st.
Paul water the first day Of last October,
and from that day up to the present time
the examinations were made daily. I
shall continue them throughout the yea".
To obtain my material I tied piece of
surgeons absorbent cotton about five
inches square and an inch tLick to the
fauset by means of a nine-ipch square OF
thick unbleached muslin. The water was
then allowed to run for eight or ten
hours, after which the cotton was brown
from the organisms it contained. Tne
cation was then washed in a certain
amount of water, and this water careful
1y examined and the number of organ
isms noted each week.
"I find that the plant life Of the city
water consists almost exclusively of al
gae, the diatoms and the desmids fur
nishing by far the most constant forms.
The diatoms have not been abundant
enough to produce grassy or fishy 0dor,
as is sometimes the case. Thirty nine
species have appeared during the six
months. OF these nineteen belonged to
the green algae, seven to the blue green
and eleven were brown algae, viz, dat
oms. The green algae are useful, Jr they
'liberate oxygen which purifies the water.
The green algae will not live in impure
water, but the blue green thrive best in
water that is impure For six weeks
after Jan. l I found an abundance of The
blue green. forms. Their presence in the
water was all the more conspicuous be-
cause of the fact that the cold wea Tier
had destroyed most of the green forms
For the six weeks mentioned the st. Paul
water was naturally of an inferior quail
| ty, but after that time the blue green al
gaze were less and less In evidence. So
| far as my observations have gone / find
| that, compared with other cities. St. Pau
| has fine quality of drinking water"