Daily new dominion. [volume] (Morgantown, W. Va.) 1897-1906, 1899-08-11


Samples of milk sealed up in tin cans
were first subjected to a pressure Of
several hundred pounds to the square
inch, but such pressures had no per
ceptible effect, and somewhat higher
pressures were tried with same result.
As there was no suitable method or
apparatus for subjecting liquids like
milk to still higher pressures, it was
necessary to devise one and this was
no easy task. Such method. howev-
er, was perfected step by step, the
pressures obtainxble increasing grad
ually until they reached the enormous
pressure of 200, 600 pounds To the
square inch. In this connection 1t is
interesting to note that this pressure
service pressure used in modern guns,
and twice as great as the highest pres
sures to which any gun in the Z. S.
Navy or army is ever subjected, even
in "the test to destruction, and this
test is only applied to one gun (Krag
Jorgensen rifie) of many thousands
manufactured. After few applications
Of these high pressures the steel cylin-
ders in which the milk was placed
would often split like pop guns aud
the solid steel pistons crush like glass.
One would hardly believe that any
living thing could survive such con-
ditions, and yet some of the germs
did survive, for the milk would gen
orally sour in time, although ii often re-
nained S,ueet for too or three toeekS.
That such pressures would not COM
pletely sterilize the milk was, of
course, disappointment to those in
charge of the work, but .being in no
way responsible for the truly remark
able vitality with which nature had
seen fit to endow these tiny things,
doubtless for good and sufficient rea-
sons, and being determined to find d
solution to che problem the effect of a
continuous low pressure was then
studied. 1t was hardly expected that
lower pressures would sterilize the
milk, but it was hoped that they
might prevent the action of the germs
and SO keep the milk sweet while the
pressure was applied II a pressure
of two or three tons should prove to
be sufficient it would be an easy mat
ter to construct d steel can in which
the milk could be shipped under such
pressures. Ten tons, however, was
found to be the lowest pressure that
could be relied upon. Lower pres
sures would prevent souring, but per-
nit other equally Objectionable
changes in odor, taste, etc. Under
ten tons pressure the milk never sour
ed, although some of the tests were
continued for two or three weeks, but
can or tank that would stand such
pressures would be so heavy that it
would probably be cheaper to ship the
milk on ice.
In as much as certain disease germs.
Notable Of typhoid fever and tuberculo-
sis, SO often find their way into milk,
it was thought worth while to try the
effect of pressure on these, and a.num
Der of samples were enoculated. At
ter remaining under pressure of ten
tons for as many days some Of all the
germs introduced were alive, although
the milk was still sweet. The results
Of this experiment ''and the fact that
other changes giving peculiar odoI
or appearance took place, although
the milk did not sour, and that sam
piles subjected to pressure never sour
ed in quite the usual way seemed to
leave no way of escaping the conclu-
sion that of all the germs to be found
in milk those which are ordinarily in
strumental in the souring must be
among those most susceptible to pres
sure. 1t is generally admitted that
the effect of pasteurization is just the
reverse of this (or practically SOY for
while this process greatly reduces the
total germ content it is especially eff
fective in destroying the disease
germs. That it is not so effective in
destroying the germs that ordinarily
contribute to the souring of milk is
shown by the fact that pasteurized
milk sonrs readily and in about the
usual way. Pressure seemed to be
most effective just where pasteuriza
tion was least effective, and Elsa Versa. ;"
This suggested a combination of
pressure and the pasteurizing temper
allure, or sort of pasteurization I'M
der pressure, which was at once taken
up and is still being studied the re-
suits being very encouraging indeed.
The milk is placed in tin cans, with
tight fitting screw caps, and by means
Of a very ingenious machine (which
could hardly be explained without the
Illustrations subjected to a pressure
Of seven TO ten tons at a temperature
of about $50 degrees f., for about one