The Norfolk Virginian. [volume] (Norfolk, Va.) 186?-189?, 1896-05-07

variations in energy, due to varying de-
grees of intensity OF human thought.
BY means OF this machine 1t may yet be
possible to throw upon a graduated
scale an indication of the difference of
effort In reading O modern novel, in
working out a hard problem In mathe-
mates or finance, or In understanding
the position of n presidential candidate.
1t may be possible to measure the mate
rial effect of anger-perhaps OF all hui
man emotion. not excluding that of love.
1t will be possible to indicate the energy
consumed in lifting your arm to the
height of your head. and even the diff
ference of the work Of your body in walk
Ing and sleeping hours.
THE MECHANICAL EFFICIENCY
OF THE HUMAN BODY.
But this is anticipating. Primarily
the calorimeter is designed to show that
a pound of food burned in the human
body gives out the same amount eff en-
ergy as though that food were taken and
burned In q furnace. And eventually
Prof. Rosa hopes to be able to express,
In figures. the mechanical efficiency of
the human body. Just as is now done in
the case of the steam engine.
What he means is this: In the case
OF a pound of coal burned In an engine.
part Is converted into cinders, part is
given Off as useless heat, and part Is
converted into actual energy or work.
Now, in the case of the engine, these
parts are expressibly in set terms. For
example, we say that In Il very fine
t~riple-expansion engine 1t Is possible to
convert something like 10 per cent. of
the total potential energy OF the coal con-
sumed therein into work. And what
Prof. Rosa hopes to find out Is what per-
centage the human body realizes as me-
chanical work out of the potential energy
of the food which II takes in and digests.
This Is the scientific statement OF the
matter. To myself | put 1t in this wise.
that this professor is trying to find out
how much OF the nutriment in II pound
of beef Is actually made use of by the
human body and converted into the en-
ergy that Keeps you warm. and enables
you to attend to business. read your
newspaper or ride your bicycles The
practical or human interest that lies in
all this to the layman. who Is not in
terested in the abstract principles OF
science, Is that one of these days we
shall know Just what kind of food will
enables us to do the most work for the
least money, and incidentally, the class
of foods that 1t is we'll to let alone.
Just the manner in which the expert
mentors ut Wesleyan are trying to find
out is this: They have constructed this
air-tisht box of copper and zinc and
wood. with oil Its varied and delicate ap-
p%liances, and into this box they put a
victim, 1 am going to call h~im-subject,
L should say--seal him up md then pro-
coed to measure and weigh everything
he does and everything he eats. Take
the air he breathcs. 1t Is drawn from
the outside atmosphere down through a
cooling apparatus, which reduces Its tenn
perature to about 20 degrees below freeZ-
Ing point. thus making 1t almost perfect
ly dry. Drawn through the box and
Dreathed by the subject, this air takes
up all the moisture given off from the
skin and lungs. This mir Is again drawn
through a cooler. which reduces 1t to the
same temperature as before. thus ex-
tracing the water II absorbed, which
may then be measured. Do you think
this Is Il small matter? Are you aware.
pray. that merely in breathing you throw
out of your lungs something like two
pounds of water every day?
H EMOTIONS REGISTERED.
Chemical analysis determines the
amount of carbonic acid gas which the
subject gives off in breathing, and also
In the ~freezers and the quantity of heat
given off from the skin is the scheme to
measure things of the person under in
v~estigation. This Is done simply by
passing n stream OF cold water at a
known temperature through "a series of
copper boxes contained In the
and then out past Il second thcrmome-
ter, which registers the change of tenn
perature. The air driven In is kept at
the same temperature as that coming
out, and the Inner and outer walls of the
oharnber are kept at an almost perfectly
HStd temperature, hence IL follows
tnat the stream of water will absorb
all the heat given off by the subject, and
so perfectly developed Is this device that
1t is already possible to measure, with
considerable eXactness, the difference be-
tween the heat expended when the pn-
tient is perfectly still and when he Is
In motion. In the case of IA Swede. who
was among the first subjects confined IN
the box, 1t was possible to crudely meas
ure the effectS OF his emotion ut being re-
leased. He had been in for five DAYS.
ana the mere pleasure and satisfaction
expressed by his bodily state was indi-
Gated in the wonderful line of light which
serves as the needle TO tho galvanometer
attached to the machine.
So far the tests which have been going
on for several months have been directed
simply to perfecting the apparatus, and
to making a long series of trials as to
the subjects condition during the vari-
Gus stages of his confinement. The prac-
teal food tests are yet to come, Later
1t is proposed to instill within the box n
bicycle, which has been made into a disc
dynamo, and set the patient at work
driving the bicycle dynamo. With per-
fectly pure, fresh air and nothing else 10
do, 1t will be possible to measure TO n
very fine piont the effect upon the patient
OF various diets. Thus these experiment
electrical units or even in foot-pounds the
amount of work which n given subiect
Will be able TO do on n diet of rumu
steak. OF rice, of milk. and the of yari-
Gus diets mixed.
1t Is thus that this machine will sun
plement the extended researches which
our Department of Aericultnre upda,