Evening star. [volume] (Washington, D.C.) 1854-1972, 1906-05-27
THE PHYSIOLOGICAL ZERO.
Temperature at Which Human Body
Feels No Sensation.

From Literary Digest
This name is given. by certain writers on
the subject. to the temperature at which
the human body feels sensation of heat
or cold. 1t might be supposed that it would
coincide in all cases with that of the body
itself, but, according to the recent expert
ments of Mr.. Maurel French physfolo-
gist. il is several degrees lower, and varies
with the nature of the surrounding me-
dunn, being lower in air than in water. Mr.:
Maurel determined his physiological zero
by tmmersing his body in baths of different
temperatures, but he does not seem to have
measured his own body surface tempera-
tUre directly, relying instead on the records
of measurements made by various earlier
authorities. This and the fact that he has
neglected to take various necessary pre-
cautions makes his results somewhat doubt
full, in the opinion of Henry Pieron, who
criticises the mthus in the Revue Scien-
tifique:
Mr. Maurel placed himself in baths of
water or air at different temperatures, and
noted between what degrees he realized
the sought for state of Indifference. He
did the same for the variations of tempera-
ture between the skin and the clothes,
which he calls the 'subvestial temperature,
and for the temperature of the body in bed
which he names 'cubtlial temperature
And he finds that the cutaneous physiologi-
cal zero lies practically between 80 degrees
and SO degrees (96 degrees and 81 degrees
F.: he even seeks to differentiate the trunk
and the lower limbs, whose physiological
zero he finds to be slightly lower. In gen.
eral the range of zero is l degree to de-
grees G. degrees to degrees F..
He also concludes that there is a rela-
ton between the physiological zero and the
surface temperature of each organ, which
latter is about degrees (o12 degrees F.)
higher than zero. But were any new ex-
periments necessary to show that the sem
saton of Indifference depends on the sur
face temperature of the body?
THE same medium should appear Icy or
hrotlinu n the fever patipnt his surface
tons of heat or cold correspond to an exit
or entrance of heat, the contact that as
sures thernic equilibrium should assure
also a state of sensorial indifference.
AT first sight it would appear odd that
one should experience sensation OF neat
when the external temperature Is Identical
with his own surface temperature. And,
in fact exact experiments in thermo-esthe-
siometry have shown that in certain spots
on the hand. for instance, drop of water
at the same temperature is not felt. But
the surface temperature Is only cross be-
tween the internal and external tempera-
ture, adapting itself to this double influence
by capricious regulating mechanism
under the direct but obscure action of the
nervous system.
Hence the phenomena Of calor1c rada-
ton toward the exterior or interior. which
provoke our sensations Of heat or cold, may
respond to numerous and imperfectly de-
| termined factors, Influenced by pressure,
| humidity, etc. from outside, and by bodily
| chemical actions, the conductibilty OF the
| tissues. etc, from inside.
Thus though rather astonishing, Maui
| rels conclusion that the physiological zero
| Is lower than the surface temperature can
| not be attacked. except on the basis OF
| new experiments.