Amador ledger., 1905-12-22
FOOD VALUE TESTS.
SCIENTISTS SEEK TO SECURE
BEST BUTTER AND BEE1.
Confine Cows to Air-Tight Cells In
Experiments = Special APP
paratus for the
Purpose.

The University OF pennsylvania at
Harrisburg has lately begun expert
ments to test foods for cattle. The ex-
periments are directed toward the sci
entific feeding of cattle to find out exact
produce the best milk, the best flesh and
the best butter.
1t is not the plan Of the Pennsylvania
scientists who are conducting the tests
to starve scientifically the cattle with
which they are making their expert
ments nor to try the effects of poison
on them. On the contrary, the sole pur-
pose of the tests is to find out what foods
or combination of foods will produce the
richest results and the cost thereof.
To make their tests correct they have
invented what they call respiration
calorimeter. 1t is an apparatus which
measures with exactness the gases
given of by a COW or an o. and the
heat generated in the animals body
during the process Of assimilation.
The respiration part of the apparatus
attends to the gases and the calori-
meter to the temperature. In this ma
chine for months past series Of the
most valuable tests has been made and
the scientists who have been supervis-
ing them are enthusiastic over the re-
suits that they have secured.
The respiration calorimeter consists
OF double-walled chamber, 6x10 feet
and eight feet high, containing a COM
Portable stall. The walls Of the cham
ber are double, the inner one being a
sheet copper, while the outer one is of
zinc, with an air space between. The
door through which the animal enters
and the small opening through which
food is given to the animal, close air
tight, shutting off the interior from the
world outside except 80 far as it can
be seen through a double plate glass
window.
When an animal Ia placed in this
hermetically sealed cell all air is cut
off from 1t, save that which is supplied
by a meter pump, which sends in a
uniform quantity Of dry, pure air at
stated inter. ais. The pump not only
sends the air currents in, but it draws
sample of it at stated intervals. An
other pump draws samples for an
analysis at the same instant that the
injector does. By comparing these
samples 1t is easy to tell exactly what
bases and how much the animal has
added to the air and to determine the
amount of gases given of by different
foods.
The copper inside box of this cham
ber is surrounded by two wooden box
es, each box being eight inches larger
than the one inside it. When in use
they are kept at exactly the temper
ature of the air surrounding the stall,
and thus there is no loss Of heat from
the chamber In which the animal il
placed.
By simple adjustment the air Is
made to leave and enter the cell at the
same temperature, and thus there is
no loss on that account. So all the
heat that the animal gives off remains
in the chamber, which is carefully
registered by delicate electrical ther-
mometers.
But If the heat remained in the cell
it would result in the place soon be-
coming unbearably hot, and so an ar
rangement is made to keep it at one
temperature by means Of coils of cold
water, which absorbs the heat almost
as fast as it is given of. The instru-
ments measure the most minute varia-
tions of heat, and these facts are class
flied with the result of air analysis.
Thus the amount of waste and heat
created by each kind Of food can be
calculated.
In making a test the animal IL
usually placed in the calorimeter be-
tween one and two o'clock in the after
noon. The next few hours are spent in
adjusting the instruments. At six
o'clock in the evening the test is usual
ly begun and usually lasts for 48 hours
At the end of that time the animal is
taken from the cell and carefully ex-
amined by experts and full report Of
its condition is made to go with the
gas and temperature analysis.
Then If the animal Is intended for
beef it is killed and samples of its
flesh, blood and various organs are put
through most careful series of anal
ysis. II it is for the purpose of i'm
proving the milk or butter supplies,
these products are tested and the re-
suits tabulated.