East Oregonian : E.O. (Pendleton, OR) 1888-current, 1910-04-22

| into heat given off from the body.
Even the raising of an arm causes a
slight escape of heat. To measure
this heat is to know the amount of
energy expended. Consequently in the
calorimeter, a man is placed in a
heat proof chamber. There are two
outer walls to this room separated by
an air SPACE about five inches in
width. Through this space are run
alternately tubes for the circulation
of cold water and wires for electric
currents.
1t is necessary that the chamber
inclosed be absolutely heat proof and
remain unaffected by temperature
changes without. To accomplish this,
advantage is taken of the law of
physics that no change can occur in
a room unless the temperature with
out it changes. If the heat in the
calor'meter rises cold water is turn
ed on in the pipes until the air in
the space between the walls is the
same as that of the room. If it drops
an electric current is passed through.
Thus the heat in the chamber is alb
solutely imprisoned. The man in the
calorimeter is fed solely upon the diet
that is to be analyzed. To measure
| the heat in the chamber determines
the exact amount of energy giving
nourishment there is in that particu-
| lar food.
Since heat is the expression of en-
| ergy it only remains to measure the
heat within the calorimeter chamber
| m dnterrnina tho aparp,- axpardod L1,
the Subject" under experiment. And
the measuring is done thus:
Water pipes, in coils much like
those used in heating houses, are run
through the calorimeter. Cold water,
| of a known temperature runs through
them. The water absorbs the heat in
the room-that given off by the man
within the chamber. The tempera-
ture of the water as it passed from the
room is again taken and the resultant
rise in its temperature gives the
amount of heat or energy generated
from the food under test. So closely
does the calorimeter register this
heat that its dials show the slight
est movement of the subject-such as
the raising of an arm.
Tests are made in the chamber
with the man at exercise and at rest.
In order to know the amount of mus
cular energy expended a stationary
bicycle arrangement is rigged up in
the calOrimeter. The hind wheel of
this is made of sheet copper. Resist
ing currents Of electricity are passed
through this wheel so that it is known
exactly the load against which he
pulls.
Analyzing The Breath.
There is now known by analysis
the constituents Of the ash from the
food and the energy supplied by it.
There remains then the gas or breath
and the quantity assimilated. The
test of the breath is made at the same
time as the test of the energy. Chem
ically measured air is passed from the
food digested-moisture and carbon
dioxide.
When the air-is drawn from the
chamber it is passed through sulphur
ic acid to extract the moisture and |
through soda lime to extract the car
bon dioxide. These two chemicals |
are analyzed after being saturated |
with the used air and the properties |
that have been given off in the breath |
from the food consumed are deter |
mined.
BY a simple process of elimination |
the constituents Of the ash the breath |
and the energy amount being sub
tracted from the original analysis of |
the food, it is found Just what portion |
Of the food was retained by the sys-
tenn and went to maintaining or build
ing up the frame
1t is by experiment with various
foods-or the same food variously |
prepared-that the calorimeter reg
isters its most valuable information
for the housewife. 1t Is this infor-
nation, translated from techn.ca! !
terms and reduced to plain English |
that Uncle Jim Wilson will use In his |
campaign for the conservation of |
kitchen resources
1t is not always the weight that |