The Portland daily press., 1875-03-08
THE FARM AND HOUSEHOLD.
Prof. Arnold's Lecture on Milk.


stances contained in pelicle OF their feshy
covering. In their composition blood and
milk are somewhat alike; the former con-
tains fibrine and albumen, the latter casene
and albumen. Where there is large secre-
erection of milk, there will be large flow Of
blood to the udGer, and hence in selecting
cows we look at the veins as well as the es-
cutcheon and udder. In its structure the I'D
der is cellular, the cells are about the size of
pin heads; it has been ascertained by exact
measurement that the elobules in milk are OF
tie same size as these cells, and therefore it
is quite probable that they are secreted from
the udder. The first among the many
changes which take place in milk occurs in
the udder. By absorption the udder is con-
stantly absorbing the fatty part Of the milk,
and therefore the shorter time it remains
there the richer it will be in butter globules.
The speakers own experiments have shown
that forty per cent more cream is obtained
from milk drawn from the COW once In three
hours than from that which remains I'M
MIXED twelve hours. 1t is therefore better
to milk as often as wa can conveniently.
The globules in milk rise to the top, form
ing cream. The butter maker endeavors to
remove the pelicle without breaking the fat,
as when broken ii becomes grease. The glob
ules are of different sizes; heavy covering
may weigh down the fat inside, and thus
affect the rising of the cream. Large and
small ones are found In the milk OF all cows,
and their size varies not only in different
breeds and animals, but in the same COWS at
different seasons of the year. The large ones
rise to tue surface first, as the covering on
the small sacs is OF abont the same thickness
as theirs, and therefore keeps them down
longer; and also in rising the small ones have
to displace more milk in proportion to their
size. Fats also expand under heat more
the rising of cream is affected. Cream is
composed of layers, the large glObues at the
top, and the smallest which rise last, at the
bottom. From milk containing the largest
and most uniform globules we get cream the
soonest, and the best butter; as when they
are unequal in size the larger are broken first
and turned to grease before the smaller are
broken.
In Jersey milk the globules are very large
and nearly uniform in size; they rise readily
and at the same time, and are easily churned
together. Ayrshire milk has a few large
globules but many snail ones. and it Is very
difficult to get them to rise, and for the same
reason it is not easy to churn good butter
from their cream. In the milk from Devon
and Dutch cows, they are of medium size.
but quite uniform, so that their milk is good
for butter. The poorest skim milk comes
from Jersey, and the best from Ayrshire
The specific gravity of milk and cream Is
50o, cream rises slowly and probably will
not all rise-heat it up to TOO and it will rise
rapidly. In cheese factories II you subject
the whey to strong heat for two hours. the
butter will all be up.
The germs which get into milk from i'm
pure water, bad feed, or by exposing cows to
the hot sun of July and August, hinder the
cream from rising. Anything of a putfe ac-
tive nature will develope in milk and hold on
to the globules and prevent their rising.
Tainted milk is always feverisn, the pellcles
begln to decay and adhere together, and this
condition you can discover by the microscope.
Milk from distillery Stops contains germs
which cling to the psllicle and check the
rising of the gobule. Cows on low and
swampy lands get from bad water these
germs.
A gentleman In Ithaca. N. Y. who bottled
his milk for winter use, found that milk from
low ground feed would not keep till winter.
Rank clover draws from the earth germs
which are injurious to milk. In making an
examination of cows milk where the cream
appeared too adhesive, DR.. Law Of Cornell
University discovered the presence Of germs,
plant forms resembling algae, with some
blood and tbSsubstance known as frog spit
tie; and all this was traced back through the
blood to the impure water which the animal
drank. Milk will not keep when sour food
is used, because the acidty passes into the
blood and thence into the milk Fastening
fermentation.
Animal odor in milk Is very troublesome,
especially at cheese factories-one can well
infect whole vat, and the cheese made from
1t will soon be destroyed. Its nature was
long unknown, hut recently II has been dis
covered to be very subtitle volatile oil; at
temperature of 500 it remains in the milk, at
$50 it is driven off; if the milk is cooled too
rapidly it will remain In it, but will be dis
covered whenever the milk is heated. Vola-
tile oils that come from the sweet grasses are
not Objectionable, and we retain them that
they may give a pleasant flavor to butter.
By many persons the evils arising from this
odor or oil, are attributed TO animal heat
this however is an erroneous idea animal
heat does not differ from any other heat, and
is no more injurious.
Milk cans for factory use should have an
opening in the cover protected by wire cloth,
and surrounded with a collar to retain the
milk which may be shaken out in tianspor-
tation. Experiment has shown that milk
thus protected and carried tour or five miles
TO the factory, has given less trouble than
that received from the immediate neighbor-
hood. BY its complete aeiation, all the ami
NAL odor has been removed.
Cheese making is process Of fcrmepta-
ton, and this is similar to, but not the same
as putrefaction; it is the growth of germs
which multiply and develop into blue mould.
A single germ has been found in milk with fif
ty stalks, each with head containing thou
sands of seeds which continue to produce
their kind. Rennet coagutates milk, turning
it into cheese, because it contains blue mould.
The germs in rennet cure cheese; it is a d.
gestive process, you digest milk with the gas
trio juice of the calf Rennet not only changes
milk to curd, but continues to act on the
cheese after it is manufactured.
Some factories are making butter and
cheese from the same milk; great progress
and improvement have been made in the |
manufacture Of skinned milk cheese; as fire.