The L'Anse sentinel. (L'Anse, L.S., Mich.) 18??-current, 1898-02-05
FILTRATION OF MILK.
Sent Upward by Pressure Through
Layers of sand.

Sent Upward by Pressure Through
Layers Of sand.
The control Of the milk supplies at its
source Is subject which Is engaging
much attention at the present time;
but, while something has been accom-
plished. nobody can really answer for
tine cleanliness of the cows and the
mixers at five o'clock on winter morn
ing on small homesteads in the country.
The more conspicuous objects. as COW
hairs, are indeed removed by straining
through coarse muslin, but quantity
OF fine dirt, which would suffice to rem
der transparent liquid visibly turbid,
will probably remain.
Some of the dirt to be seen at the bot
tom OF pail, jug, or even glass, con-
sists of aAnnneral dust, but the greater
part is neither more nor less than COW
dung. fact which furnishes an obvious
explanation of the myriads of bacillus
coli present in so many samples of
milk; yet, strange to say, no one seems
to think it necessary to filter milk,
though it always contains a vast num-
Der of the bacilli, fraction of which
would be deemed sufficient to condemn
any water as unfit for drinking, and
the known outbreaks of typhoid fever
traceable to milk are far more numer-
Gus than those attributable to public
water supplies, for milk presents an ex-
cellent culture fluid for the bacilli of
tine bowel
Sand filtration of milk on its arrival,
whether by road or rail, at the central
depot has been practiced for several
years in some cities, as by the Copen-
hagen Dairy company and by Messrs.
Bolle, of Berlin, whose arrangements,
alike for the purity of the milk and for
the physical and moral welfare of the
persons lover 1000 in number) in their
employment, are well worthy of imita-
ton. The filters used in this dairy con-
sist of large cylindrical vessels divided
by horizontal perforated diaphragms
into five superposed compartments. of
which the middle three are filed with
fine Clean sand sifted into three sizes,
the coarsest being put into the lowest
and the finest into the uppermost of the
three chambers.
The lowest of all is partly occupied by
a perforated, inverted, truncated cone,
which assists in supporting the weight
of the filtering material. The milk en-
tiers this lowest compartment by pipe
under gravitation pressure, and after
having traversed the layers of sand
from below upward, is carried by an
overflow to a cooler fed with ice water,
whence it passes into a cistern from
which it is drawn direct into the locked
cans for distribution.
1t is the rule of this dairy, also, when
ever any epidemic or epizootc occurs
in the districts whence its supplies are
obtained, to subject the whole before
admission to the filter to temperatures
first of 100 degrees Fahrenheit, and
then about 220 degrees Fahrenheit, in
two apparatus interposed in the course
of the pipe supplying the filter. The
filtered milk is not only freed from dirt,
but the number of bacteria is reduced
to about one-third. without sterilizing;
The loss Of fat is in new milk stated to
be small, but the quantity of mucus and
Shiny matter retained in the sand
which is, Of course. renewed every time
lis surprising.-British Medical Jour
nal.