Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1903-05-14

Boston, May The question Of the
purity or impurity of public water
supply j. naturally one of the most i'm
portant matters that modern science
has to deal with. Until recently
chemical analysis has been considered
the most authoritative method Of ap-
preaching the problem, while the
science Of bacteriology- has to
do with the examination of the vast
number of little organisms that exist
in water-has been supposed to be Of
less value. Within the last few years,
however, meteorological investigation,
largely as a result of what has been
accomplished at the Massachusetts
Institute of Technology, has been gen
orally accepted by engineers and prac-
tical santarians as a quicker and more
direct means of learning Whethe
water is healtful or Unhealthful-IOt,
indeed, by finding actual disease-pro-
ducing bacteria but by discovering
certain other organism whose pres
ence in large numbers is always proof
luted with sewage, and proof presUmp-
tive, of the presence of their more
dangerous brethren. The colon baciln
and the streptococci, as these tale
bearing bacilli are called, are not
harmful in themselves. In fact they
are distinctly friendly to mankind and
have given the scientists a rapid
method of finding the local source Of
typhoid and other water-bOrne cpl
denies
Very few persons are likely to see
a colon bacillus even with a powerful
microscope, yet it is SO widely diffused
that it exists practically everywhere.
But it only develops in large numbers
under special conditions of lighter
rather darkness-warmth and nOur-
ishment, and it is this strenuous and
patriotic development that makes 1t
such an excellent water test. If you
should examine a drop of water under
a microscope the colon bacillus would
be one of the many organisms that
you probably would not see at all be
cause they were so small. Perhaps,
in that particular drop of water, if it
were very pure, there would be 40
colon bacillus whatever; but if there
was any pollution the little bacillus
would be there living upon it. And il
the proper conditions of warmth, dark
ness, and nOurishment were provided
the bacillus would soon begin to di-
vide itself and produce what the bac-
teriologists call a colony.
These colonies are the real test for
impurities in drinking water. A small
quantity of the suspected water
usually a cubic centimeter, or, roughly
speaking, about thimbleful-is
mixed with a solution that contains
nourishment for the bacillus and a
certain amount of deXtrOse, a kind of
sugar which the colon bacilli not only
enjoy but have the property Of caus-
ing to ferment. This mixture is placed
in tube, shaped like the letter U
except that one arm is much shorter
than the other, and the tube put away
for "A hours in an oven heated to
blood temperature. When the tube is
place. in the oven both ends are
closed, with the LIQUID entirely filing
the shorter arm. If the colon bacilli
are present they will ferment the
dextrose in the solution, producing
gas that rises and forces the liquid
backward: so that when the tube is
again examined there is an apparently
empty space where the liquid had
been when the bacilli were first set
aside to incubate.
If you should now look at this solu-
ton under 4 microscope you would
probably see the colon bacillus, 0rI
rather hundreds and hundreds oil
them, hurrying here and there in the
mixture and looking for all the world
like miniature live sausages. But this
one experiment is not absolutely con
elusive; there is another little organ
ism, recently discovered in the In
stitute of Technology laboratories,
which destroys the colon bacillus and
does not produce a gas from the
sugaTy part of the solutiOn-an or
ganism. in other words. which would
neutraliZe the experiment Just de-
scribed. Actually to prove that the
colon bacillus was not present-with
all that its presence implies-in the
original cubic centimeter of water.
demands. therefore, a series of other
tests made for the purpose of differ
entiating this particular organism
from others which closely resemble it.
One of the simplest of these tests is
to srOw the b3ciIi in gelatine thinIy
spread over a glass plate and shut up
in the park at an ordinary tempera-
ture. A little of The suspected water
IS mixed with the gelatine and if this
water contains bacteria, invisible even
to the most powerful microscope, they
will Immediately begin to feed and
develop. The colon bacillus grows by
dividing itself into two similar organ
isms-a process which takes about 20
minutes under favorable conditions
and the colonies which result, having
more inhabitants than a state in the
American union, are plainly visible 10
the naked eye. In fact a bacteriologist
growing bacteria is much like some
Brobdignagian farmer who should
plant Liliputian seeds without know
ing what they were going to produce
but when the crop was grown recog-
nized his acres of corn by the green
and yellow masses of the growing
the total effect of hundreds and nun
dreds of them all massed together.
But even after the bacteriologist has