Herald and news. [volume] (West Randolph, Vt.) 1878-1943, 1898-12-15
FILTRATION OF MILK.
sent Upward by Pressure Throusn
Layers of Sand.

! sent Inward by Pressure 1hfous
Layers of Sand.
The control of the milk supplies atits
,ource is a subject which is engaging
much attention at the present time;
hut. while something has been accom-
plished. nobody can really answer for
The cleanliness of the cows and the
mixers at five o'clock on winter morn
tng 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 a pail, jug, or even a glass, con-
sists of a mineral dust, but the greater
part is neither more nor less than COW
dung. a fact which furnishes an obvious
explanation of the myriads Of bacillus
coli present in so many samples OF
milk; vet. 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 waller 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
the bowel
ff4-,tfc., of ~ I'LL d ffc 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 tine middle three are filled with
fine clean sand sified 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. fruncated cone.
which assists in supporting the weight
of the filtering material. The milk en-
tiers this lowest compartment by pipe
under gravi;ation pressure. and after
having traversed the layers of sand
from below upward. Is carried by an
overflow 10 a cooler fed with ice water.
whence it passes into a cisiern from
which ii is drawn direct into the locked
cans for distribution.
II ia the rule Of this dairy. also, when
ever any epidemic or epizootic occurs
in the districts whence its supplies are
obtained, TO subject the whole before
admission TO the firer TO temperatures
first of 100 degrees Fahrenheit. and
then about 220 degrees Fahrenheit, in
two apparatus interposed in he 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 sierilizing;
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 urprising.--British Medical Jonr- |
nal.