Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1883-01-31
Fooliag the Senses.

Immerse the torehnger of one band
in water at 104 degrees Fahrenheit, and
then plunge the whole of the other
hand into the water with temperature
OF 102 degrees Fahrenheit. The latter,
although two degrees cooler. viii be
Judged to be the warmer of the two,
from which it appears that the intensity
of the sensation of temperature depends
not only upon the relative degree oil
heat to which the parts are exposed,
but also upon the extent of surface over
which it is applied. From this cause
bath which is not uncomfortably warm,
when a few fingers are dipped IN 1t,
appears scaldnIg hot when the whole
body Is immersed. The sense OF tenn
perature is likewise, entirely at fault
when required to determine which Is
the warmer OF two substances, say a
piece OF iron and a piece of wood, for II
they both have the same temperature,
the iron will feel the hotter OF the two,
because Of Its being so much better
conductor. A slight difference OF tenn
perature, however, between two sub
stances of ike nature is easily dlscerned,
and we may here describe a simple but
Misunderstanding trick which Is found
ed on the fact.
The performer, having placed his
hat behind him, requests the people
present to place in it three or four pen
nies. He shakes it up behind him, and
then asks some person 10 take out a
penny and closely examine 1t. He
has then to pass 1t to the others for
examination, the last one pitching 1t
back into the hat again, The pennies
are then shaken up, and the performer
now, placing one hand behind him,
picks out the penny which has been
examined. although throughout the
whole operation he has never seen 1t.
When the experiment has been done
some two or three times successfully,
all sorts OF unlikely suggestions are
made as to the way in which the feat
has been performed, but very seldom
the night one, which was exceedingly
simple. the people, IN handling the
penny which was selected from the
others. make it warm. 1t Is, therefore,
easy to pick il out from the others when
If has been pitched into the hat again.
This sufficiently demonstrates the fact
that at ordinary temperatures the sense
of temperature as localized In the fin
gers is sufficiently sensitive to descnmi-
nate between several pieces OF metal so
as to say which is the warmest.
But for the extremes of hot and cold
touch is thoroughly deceived, piece o
frozen mercury giving a burning sensa
ton ike a red-hot bar of metal. Iht
touch which attans to such perfection
in persons afflicted with blindness /:
readily deceived. This is shown forci
bly, by the experiment OF Aristotle
Cross the index and middle fingers anc
run them over a marble placed on the
on the table with the eyes shut. Undel
such circumstances one has difficulty Il
avoiding the belief that he is dealing
with two marbles instead of one. Th'
idea of roundness which has been OBJ
tanned by complex Judgment, founded
on the coaIescence of several sensations
Is here appealed TO, but the usual con
di1ons being reversed, we draw wrong
conclusion. The sense OF taste may bt
likewise copf JuLded by altering th'
conditions. under which the gustatory
operation Is always carried on. Thus
II The nostrlls be held firmly, it Is i'm
possible TO distinguish between ap
plying an onion or an apple TO the
tongue.