Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1893-01-31
TESTING CREAM.

A correspondent Of the Lewistor
Journal sends the following query
..Can cream be tested by the Babcocl
tester the same as mllkT
DIR. Babcock ln . late bulletin from
the wisconsin Experiment Station
answers the question Of our correspond
ent a. follows:
The chief difficulty In testing cream
lies In the sampling. Cream that U
sour, or that has been exposed to ali
until the surface has dried cannot b
accurately sampled. The same is true
Of centrifugal cream that is badly froth
ed. Sweet cream, from Cooley caus
that Il not too thick to dow readily from
the plpette, may be tested with satisfhc
tory results. The process, however
must be modified sllghtly from that US
ed with milk, ss the amount OF Tat 10
cream Is so large that II cannot bt
measured In the ordinary test bottle, U
the usual quantity is taken Tor the test
besides much greater error results
from the cream that adhercs to tht
pipette than with milk. Both OF thess
difficulties may be overcome by taking
two or three test bottles and dividing
the test sample between them Into as
nearly equal portions as can be Judged
by the eye. The pipette is then filled with
water and this Is run Into the tubes tht
same way as the cream. IL three bottles
are taken the pipette is filled with water
a second time aud emptied into the bot
ties as before. This serves to rinse the
cream from the pipette, and at the same
time to dilute II to point where II can
be tested In the same way as milk. The
bottles are then treated In the usual man.
ner and the reading Of the tubes added
together for the per cent. OF lat In the
cream.
The necessity of dividing the sample
Of cream as directed above may be avoid
ell by the use Of q special test devised by
Mr.. j. VI. Bartlett Of the Maine Experi'
ment Station. This bottle differs from
the regular test bottle In having a bulb
blown In the neck, the graduation COM
mencing below the bulb, which holds lO
per cent. With this bottle cream up to -
to IS per cent. of fat may be tested In
the same manner as milk.
Owing to the low specific gravity OF
cream, the test sample, II of the same
volume, will weigh less than that OF milk,
and consequently the per cent. OF TAT as
shown by the scale will be less than IL
found by gravimetric analysis, In pro-
portion as the weight Is less than IL gins.
If7.6c. c. Of cream Is taken aud the
portion adhering to the plpette Is rinsed
into the test bottle, a close approxima-
tion Of the true result may be obtained,
without weighing by correcting. the
scale reading, by correcting the scale a.
follows: for n scale reading of 20 per
cent. add .25 per cent. for a scale read
Ing Of Is per cent. add 0.l per cent.
Readings between these may be correct
ed In proportion. Below 10 per cent.
no correction Is necessary.
Cream may be tested In the ordinary
bottle In the manner proposed by Mr.
winton, Ia Bulletin los, OF the Connec-
ticut Experiment Station, by using a
pipette having a capacity OF G.Oi c. c.
which will deliver up about grams OF
average cream, or one-third OF the
weight Of the usual sample. When this
pipette Is used, about II c. C. OF water
should be added to the cream In the bot
tie before adding the acid. The usual
amount of acid should be taken and the
test completed In exactly the same way
as with milk. The reading should be
multiplied by three to obtain the per
cent. of fat In the cream. No correction
for the specific gravity u necessary
when this pipette Is used. With either
of these notifications the test may,
with advantage, replace the oil test
churn In gathered cream factories.