The Cook County herald. [volume] (Grand Marais, Minn.) 1893-1909, 1898-10-01
1actsria II Toe,

Inc following IL from the WORK ~
Professor Vol on the Principles 81.
Modern Dairy Practice" He says: Al
though we find q .consid erable number
OF bacteria In Ice under certain condi.
lions. It is, however, . fact that every
time water freezes It's bacterial content
.is considerably diminished. Ftankei's
nVest1gations show this plainly. Wa
ter from the river Spree containing
.66, GOO bacteria per cubic centimeter
froze at 1918 r. After two days one
cubic centimeter. contained only 1900
bacteria, and after nine days only Ia
bacteria. IN another sample 5000 bac-.
terra were found per centimeter at the
beginning OF the experiment, and after
three days freezing only 20 bacteria
were found IN the same volume. A
third sample. which was highly in
Tested with bacteria, containing not
less than 5000 per cubic centimeter,
showed only $4,000 bacteria per cubic
.centimeter after six days. freezing.
The freezing is therefore a powerful
means against the development of the
bacteria in the water. It is in reality
of no great Importance that absolute
steril1ty cannot be obtained from the
water in this way, as the bacterial con-.
tent by this method will be extremely
small, provided the water is not highly
infected before freezing. :.
In the meteorological analysis Of the
Ice that I have made I have obtained
greatly varying results, according to
the origin of the ice. In examining
thick lake ice in the center of a large
block OF ice the analysis proved It to
be entirely free from bacteria. On the
surface of this block, which was ex-
posed to infection during cutting,
hauling, ETC., an appreciate quantity
was, on the other hand, found, rang
Ing from 20 to 400 per cubic centime-
ter. Only one inch deep no bacteria
was usually found; sometimes, how
ever, couple OF bacteria colonies ap-
peared on the gelatine plates in the
ARCHAEOLOGICAL ANALYSIS. This block OF
Ice was taken from the lake in March
and hauled to an ice house; the anal
ysis was made in the following August.
Even porous, soft ice has proved very
poor In bacteria, sometimes entirely
sterile, If it did not come from the sur
face layer. This was found to be the
case in ice taken from lake where
no city or factory was situated. The
results Of analyses made Of ice from
the harbor of Helsingfors were differ
ent. They, Showed that the water must
have been very rich in bacteria before
freezing, for about two months after
the tharbor2 was frozen over the ice
contained between 260 and $500 bac-
terra per cubic centimeter. The ma
terial for these analyses was taken by
myself from the ice in the harbor. No
Ice free from bacteria was found in
this place.
My investigations concerning the
bacteria of ice have also proved an
other fact, which still more confirms
my opinion that recently melted Ice
water is to be preferred to even very
pure well-water in the dairy work. The
Investigations showed that In the case
Of bacteria remaining in the ice for e
long time their virulence, that is, their
power to develop their specific quail
ties, was greatly diminished. This
multiplication took place very slowly,
and where the bacteria were made up
Of fermentation starters, the fermenta-
ton developed considerably more slow
~ and less intensely than was usually
the case. I also observed that some
Of the ice-water bacteria which did not
show any Preventative power on the
first incubation cultures, after having
later reached their normal conditions
again possessed this power. The in
vestigations were made both with the
Tactic acid bacteria and putrefactive
bacteria. The former, which caused a
complete fermentation in milk before
the freezing by being kept for twenty
four hours in an incubator at Sc F,
were unable to produce even something
like similar characteristic fermenta-
ton in several days after having been
enclosed in ice for two weeks.