The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1897-11-28
E1Uf1AN BODY A FUEL MACHINE
Remarkable Experiments Prove That Mechanically We
Are the Same as a Steam Engine.

/ that is used is a fixed and definite guam
Jlty. A pound of COAL for example, IS ca
pab!e OF giving out, when consumed,
definite number OF heat units. no more,
no less. and the same is true OF every
other combuSuble substance. AS num-
I berless tests have established the heat
values Of al familiar combustibles. il is
comparatively easy for the physicist to
lnoute the stored potential energy of
any substance OF which the chemical
composition is known.
Such being the case, Professors As
bury and Rosa thought it would be high
~ interesting to ascertain by actual eX-
pertinent the status of the human body
as heat engine. They therefore de-
ViSed cabinet OF unique construction,
made as nearly impervious as possible to
! heat, supplied with air through one regis
terlng meter and ventilated through an
other: in short, equipped with all posi-
bic devices for refined measurements.
Within this cabinet the person to be eX-
perlnented upon lived for a given number
of days, eating, sleeping and following
/ routine OF work as nearly normal in
character as the cramped quarters would
permit The most vigorous work per-
formed was the riding of a stationary BIZ
cycIe which was driven the equivalent of
a certain number of miles each day. A
certain number of hours were also de-
voted to active study or reading.
Every particle of food consumed by the
subject was most carefully weighed and
its heat value carefully estimated; and
| food. in this sense, it should be under
1 stood, includes both air and water. From
i this amount, the heat values of the pro-
/ ducts given out by the body unconsumed
| were, OF course, Subtracted. The differ
! ence represents the fuel actually burned
by the human machine. Meantime, the
exact amount of work performed by the
! person had been registered, and this. of
/ course, accounted for a measurable
amount of the heat evolved by the fuel
! consumption. The really difficult and
! novel part of the problem was to ascer-
/ tain whether the amount of heat radiated
from the body into space, or carried off
! by the air, accounted for the balance of
! the heat which the animal fires had set
free.
REMARKABLE EFFECT OF RAISING
THE ARM.
To answer this question, most ingeni-
ouSly placed thermometers We're called
into uSe-thermometerS OF such delicacy
that they registered the most infinitesi-
NAL changes in the temperature of the
cabinet and it's surroundings. For eX-
ample, the assistant without the cabinet
on guard to register results, noted one
night d sudden rise in his thermometer,
which had been for some time stationary,
the subject within the cabinet being
asleep. Unable to account for the sudden
rise, the assistant went to the window of
the cabinet and Deered in, when it ap-
peared that the subject had awakened
ana reached out his nand tor his watch
to note the time. The amount of physical
eEert4on necessary to- raise his arm had
Set free enough additional heat to raise
the temperature of the entire apparatus
and affect the thermometer in the way
noticed.
Since such inf1nitesimal changes of tenn
Derature were recorded by the delicate
apparatus it goes without saying that
during the day, when the subject was
constantly occupied in one way or anoth-
er, the thermometers showed constant
fluctuations OF temperature, and required
to be constantly observed tC, make sure
of accurate and correct results being re-
corded. The details of these results nave
not as yet been published, nor would they
interest the general reader if they had
but the general result, as recorded by
Professor Rosa, is to confirm the conVic-
ton that the human body, considered as
q heat machine is governed by precisely
the same laws that govern any other ma
chine that consumes fuel All the hea
potentially contained in the fuel Which
was taken into the body in the form O.
food, water and air, was accounted for by
the measured quantities of unconsumet
combustibles given off by the body, plu!
the work done. plus the heat actuall!
thrown out by the body. In other words
the law of the conservation of energ!
was shown by these experiments to ap
ply to the human body as accurately al
it does to any non-living machine.
1t was a curious and interesting fac
that purely mental efforts, dissociate,
from any physical motion, did not in
crease the heat given off by measure
: able amount So it seems that the mos
active mental effort does not require S
much expenditure of mechanical energ
as raising the arm.
-D-<r-7, o.
Indicating Directory.
Philadelphia Times: A curious in
r-o,+;o,, &c +l,a dav,ioa of q D1ll1fh ma