El Paso herald. (El Paso, Tex.) 1901-1931, 1913-04-03
FARMING
CARE IS REQUIRED
IN TESTS Of MILK
Bulletin Issued by State
College Tells How 1t
May Be Done.


issued bv the experiment station gives
directions for operating the Babcock
test. The bulletin says;
The Babcock test is a means OF deter
-.,f~i-,r- the Dercent OF tat in milk,
rream and other dairy products Inc
tester is a machine Wnlcn separates the
the fat from milk by cenIrlIusaI force
ma brings it into the graduated neck OF
the milk bottle so that the percent OF
far in the milk may be READ dlreclIy-
The equipment consists Of the tester
nroper. called the centrtuSe, a ls-6 c C.
5,iDerte milk and cream test bottles, an
acid measure, a quantity OF sulpnurlc
acid, and a pair OF dlFlders- a com
Dlete two-bottle outfit suitable lor
farm use, can be purchased Tor
Accuracy Is Necessary.
In making the test, great accuracy
is required Before taking sample,
the milk should be wei mixed by
Shaking If the milk is 10, Il should
be warmed in water heated 10 dD"uI 10
degrees Fair. then shaken thoroughly
OF poured back and tocth rom one pot
tie to another, so that me butter TAT
may h. thoroughly mixed with the milk.
The 17-6 c c. pipette sh1Ul1 be inserted
Immediately and the MI X sucked TO 4
little above the mark on the neck d me
pipeute. The right fOreUnSec can ne
placed quickly over the top OF tho
pipette 10 hold the milk If the finger
is dry, the pressure may be released 10
allow the milk 10 run Gown Nlll4 even
with the mark. The milk should iaen
be transferred without loss TO the milk
bottle. This can be done most easily by
holding the bottle in IN ;ncilne1 posi-
tion and allowing the milk . run down
the side OF the bottle neck
Sulphuric acid of specific gravity OF
1.S2 to 1.83 should be added. The amount
to use is rs C. C. The acid measure Is
marked to indicate that amount II too
little acid is used or the aCi IS too
weak, the casein VIII not be all DIS
solved and the test viii DE spoiled. If
the acid is too strong or too much is
used. the casein will be burned and
black charred substances will inter-niE
with the fat In adding the acid, the
test bottle should be held in an in
clined position and the acid allowed 10
run down the side of the bottle The
acid. being heavier than the milk, goes
10 the bottom and forces the milk Up
Shake the bottle Immediately with ro-
talry motion until the acid and milk are
thoroughly mixed. The action Of the
acid is to dissolve the sOiids-nOt-fat in
the milk The chemical action causes
the mixture to become very not and al
most black in color
While still hot, the bottles should be
placed IN the centrlfuge ana Whlr1ed
al the proper speed Different ma
chimes require different speeds and one
should follow the directions that &C
company the outfit The required
speed may vary from 500 to 1900 rev.
buttons of the wheel per minute, ac-
cOrding to the diameter of the wheel
After v hirling for tive minutes, the ma
chine should be stopped and hot water
Of a temperature Of 40 degrees Fair
should be put IN IN sufficient quantity
to bring the fat up to the neck Of the
bottle Then whlrl for two minutes
more and add water TO bring the tat
all within the graduated portion Of the
neck " hirl again for one minute, to
make sure all the fat has come unto the
bottle neck and to clarity the line be
tween the fat and the water
The fat as it appears in the neck Of
the test bottle should have a yeuOwish
or straw color, and be clearly dist net
from the water below Any black or
1Occulent matter in or at the edge OF
the fat column should not OccEr Il the
test is conducted properly.
Read While Bottles Are Hot.
The reading should be rGRea while
the bottles are still hot 125 o 10 ce-
grees FAIR IS the temperature al = 6lSh
the reading should be ma Ie- If the
bottles cool before the reading IS maze.
they should be placed IN a water bath
OF the required temperature and then
read To read the test, the dividers
are used, placing one point at the bot
tom of the fat column and the other
at the extreme top Then without
changing the angle of the dividers, they
are placed with one point at the zero
mark, while the other extends up along
the bottle neck and indicates the per-
centage Of fat The milk bottles are
graduated so that when 11.6 G c Cor
IS grams) of milk are used the amount
of fat may be read in direct percentage.
The graduated portion is divided into
10 spaces, each representing one per
cent These spaces have five divls-
ions, each representing one-fifth or
twO-tenths Of one percent.
Testing cream requires the samples
to be weighed instead of measured o.
the plpette- This is because an Gcru-
rate sample cannot be taken by the
latter method Eighteen grams If
cream are required, while the 17.6 c. O.
81 q mHmH
grams, depending on the richness OF the
cream in butter fat Cream also mas
tendency TO stick to the sides OF The
pipette, which prevents an accurate
sample from being take1. Special bal
ance scales are best adaptcu for weigh
ing cream samples
In taking cream samples, the same
precautions as in the case of milk
should be taken to get q fair sample.
Eighteen grams of cream should DE
weighed into each cream bottle. Usually
q little less than us c. C. Of acid is SUI
nclent Tor cream, as there is less aSCiu
to dissolve The mixture Of aciI and
cream al first should have a light choc-
oiaJe color, gradually changing to
black as the test proceeds. The pro-
cess OF centrifuginS and reading the
test IS the same as for milk, except that
the fat is measured from the bottom of
the tat column to the lower edge Of the
meniscUs.
Some people prefer to use only nine
grams of cream, in testing There are
special bottles made for that amount
Nine grams can be tested with the or
binary IS gram cream bottle by simply
multiplying the result by two to s,et
the corrected reading. The objection
to using only nine grams of cream is
that in case of error the error is twice
as great by the nine gram method as
where Is grams are used.
Testing Skim Milk.
Testing skim milk requires a special
double necked bottle that viii read a
fat test as low as ve-hundredths Of
one percent Ordinary separator skim
milk or buttermilk should contain oniv
five to ten hundredths Of one percent
OF fat which is too low to be read ac-
curately in the ordinary milk bottle.
us c. C. Of skim milk should be meas
ured with the ordinary milk pipette
and the side tube. As skim milk con-
tains more sOlids-nOt-fat than whole
milk, more. than 17.6 C. C. of acid IS
needed 10 to 20 c. O. is the proper
amount to use. 1t should be added in
two portions, shaking carefully after
each addition to mix thoroughly with
out getting any solid matter into the
small neck or squirting any acid on the
operator. in centrifuEing. the whirl-
ing should be continued for one or two
minutes longer than in the case of
v hole milk Usually the graduated pOr-
ton OF the neck is divided into five
spaces, each representing five-hun-
dredths of one percent The fat column
may be raised or lowered to a position
to be read more easily by placing the
finger over the mouth OF the side