The Portland daily press., 1878-04-25
AGRICULTURAL.

Good milk is impervious to the rays oflight
and of white or very family buff-tinted COL
or, while it undergoes no change on being
heated. 1t has sweet taste and slightly
perceptible, agreeable odor. Its opacity is
caused by multitude of little particles or
gobules, held in suspension by clear liquid,
and which can only be discovered by micro
scopic examination. These globules are of a
fatty nature, and being lighter than the sur
rounding liquid gradually rise to the surface
and form the cream, which collects at the top
of the milk that is allowed to repose. Few
articles of food are more liable to adulteration,
the nature of which adulteration in the case
OF milk consists generally in the addition of
water and the removal of cream, by which
this important item of daily consumption is
robbed of a large portion of its nutritious con-
stituents.
Nearly all the methods of testing milk Or
dinarily adopted are open to the objection that
they are either untrustworthy or occupy too
much time. Judging of sample of milk by
its specific gravity alone is simply absurd,
since the simultaneous abstraction of cream
and addition OF water may be so managed as to
leave 1t in that respect unaltered. To substi-
tute for the test by the lactometer a complete
chemical analysis, or by an estimation OF the
cream or the solid constituents, occupies con-
siderable time, involving delay of hours, in
addition to quite an expense 1t would seem
that herein was wide field for the display of
inventive genius, and when the population of
large towns and cities determine to buy only
pure milk, instead of the sadulterated article
which is now supplied, an active demand will
arise for some economical and expeditions
method of determining the food value of such
milk as is offered for sale.
In this connectionan European chemist,
Prof. Feser, has invented an improved lacto-
scope in the shape of a simple instrument, for
measuring the degree of opacity, or absence of
transparency, of milk, which is, of course, de-
pendent on the proportion OF fat in it. This
lactoscope consists of glass tube about eev-
en- inches long by one and one-third inches in
diameter, except at its closed end, where the
diameter is greatly reduced. Attached
to the bottom of the inside of the tube
at fixed distance from its sides is a short
white-porcelain rod, on which several black
lines are enamelled. The tube itself is grad.
uated in cubic centimetres (0393 inches) and
also bears scale registering the percentage of
fat contained in the milk under examination.
To find this a small quantity about four Gu
bic centimetres Ia cube of about one and a
half inches)-of the milk, which must previ-
ously be thoroughly stirred up, is introduced
into the tube, while water is added little by
little till its opacity is so reduced that the
black lines on the rod become visible. By
reference to one set of graduated marks On
the tube it may be ascertained how much wa
tel has been required, while the other records
the corresponding percentage of cream present
in the samples. The richer a milk is the more
water will it require for the completion of the
test, while the more it has previously been
watered or deprived of its cream the less ad-
ditional water will be needed to bring the
black marks in view. The increased con-
sumption of milk as diet, and the develop
ment of this most remunerative branch of
dairying, is largely dependent on the purity Of
the supply when delivered to consumers
American Cultiuator.