The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1914-09-12
DANGER OF ICE INFECTION.

n
The modern practice Of using iced
food and drinks rs SO universal in this
country that it is important to deter
mine to what degree ice may be relied
on as not carrying infection. When in
the seventies and eighties of the last
century it was shown that pathogenic
bacteria might survive freezing, ice
fell under suspicion as possible me-
dunn for the transmission of disease;
yet few epidemics have been ascribed
to it, and the evidence concerning
these has been regarded as inconclu-
sive. H. S. Cumming in a recent arti-
Gle in the United States public health
reports makes study from the point
Of view of the source of ice, the phys
ical and biologic changes accompany
ing or consequent on its formation,
and the methods employed in its COL
lection or manufacture and handling
Ice is either natural or artificial.
Until recently, in order to secure clean,
transparent artificial ice, 1t was neces-
sary to distil the water used, thus de-
stroying all disease germs present.
With the newer methods employed.
filtration is held to be sufficient. Cum
ming remarks that the fact. well
known to chemists. that during crys-
utilization nearly all extraneous sub
stances are expelled from the crystal.
was overlooked by sanitarians until
recently. AS Whipple says, Quail
tatively the early bacteriOlOgists were
right: quantitatively they were wrong"
In the formation of natural ice, most
of the impurities are expelled into the
- I1,
same result is attained by the newer
methods of artificial ice making. By
the "can" method, cans of water are
immersed in the freezing mixture. AS
the freezing proceeds, the impurities
are forced toward the center. In one
Of the newer methods, large cans are
used, and the cakes of ice are cut into
smaller ones, eliminating the dirty
core. By another new "can" method,
the impurities are expelled into about
six inches of water kept liquid by agi-
tatiOn. In the plate" method, the
water is contained in large tanks, on
one side Of which are pipes containing
the freezing mixture. The water
freezes next the pipes in plates about
II inches thick. and the impurities are
expelled into the water beyond.
Some natural ice is undoubtedly de-
rived from polluted rivers or ponds.
Three great factors tend to purify ice
from polluted waters: The first, as
just mentioned, is capitalization. The
second is temperature-the fact that
freezing destroys a large percentage
of bacteria. The third and most i'm
pOrtant is time. The longer the time
intervening between the infection of
water and its use (as>water or as ice),
the slighter the chance of the survival
of the germs. On this score, natural
ice, which is collected and stored for
several months before shipment, has
the advantage over artificial ice, which
is usually marketed soon after it is
made. Owing to these three factors
capitalization, temperature, time
clear, clean ice is Of itself as free from
danger as could be wished Artificial
ice made from pure water in clean,
sanitary factories may be regarded as
safe: SO also may natural ice cut from
reasonably pure deep ponds or lakes
and stored under sanitary conditions.
Artificial ice made from polluted
water in dirty, insanitary factories is
unsafe; natural ice cut from shallow
polluted ponds or from grossly pol
luted rivers is also unsafe. Any dirty
appearing. cloudy ice may be infected
as well as polluted: no such ice should
be used in contact with food or drinks.
Ice which is otherwise safe may be-
come infected by improper handling
by being dragged across dirty streets
or sidewalks OF distributed by unclean
hands. This is the great source of
danger. Summing up the situation,
the Journal Of the American Medical
Association says that W. may prac-
tically eliminate danger by avoiding
the handling Of ice with dirty hands.
by washing the ice with pure water,
and by using only clear ice.