The evening times. [volume] (Grand Forks, N.D.) 1906-1914, 1906-05-02
THE PHYSIOLOGICAL ZERO.
Temperature at Which Human Body
Feels No Sensation.


This name is given by certain writ
ers on the subject. to the temperature
at which the human body feels no
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. a French ply
siologist. it is several degrees lower,
and varies with the nature of the sur
rounding medium. being lower in air
than in water. Mr.. Maurel determined
his physiological zero" by immersing
his body in baths OF different tempera-
lures, but he does not seem to have
measured his own body surface tenn
perature 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 precautions makes
his results somewhat doubtful, in the
opinion of Henry Pieron, who crit
ciseS them thus in the Revue Scien-
tifiQue:
"Mr. Maurel placed himself in baths
of water or air at different tempera-
lures, and noted between what de-
grees he realized the sought-for state
of Indifference He did the same for
the variations of temperature between
the skin and the clothes. which he
calls the 'subvestical temperature, and
for the temperature of the body in
bed. which he names 'cubilial temper
ature.' And he finds that the cutane-
GUS physiological zero lies practically
between 80 degrees and SO degrees
CSC degrees and 81 degrees F.); he
even seeks to differentiate the trunk
and the lower limbs, whose physiolog-
ical zero he finds to be slightly lower.
In general the range of zero is / de-
gree to 2 degrees q degrees to 4 de-
grees F)
He also concludes that there is
relation between the physiological zero
and the surface temperature of each
organ. which latter is about degrees
(5h degrees F.) higher than zero.
But were any new experiments neces-
sary to show that the sensation of in
difference depends on the surface tenn
perature of the body?
THE same medium should appear
icy or broiling to the fever patient,
as his surface temperature oscillates.
And as the sensations of heat or cold
correspond to an exit or entrance of
heat, the contact that assures thermic
equilibrium should assure also state
of sensorial indifference. q.
"At first sight it would appear odd
that one should experience a sensa-
ton of heat when the external tenn
perature is Identical with his own sur
face temperature. And, in fact, exact
experiments in thermoesthesiomet
have shown that in certain spots on
the hand, for instance, a drop of water
at the same temperature is not felt.
But the surface temperature is only a
cross between the internal and ex-
ternal temperature, adapting itself to
this double influence by capricious
regulating mechanism under the direct
but obscure action of the nervous
system.
Hence the phenomena of calorifit
radiation toward the, exterior or in.
terror, which provoke our sensations
of heat or cold, may respond to mum.
erous and imperfectly determined fac.
tors. influenced by pressure, humidity
ETC., from uotside, and by bodily chem
ical actions, the conductibility of the
tissues, etc.. from inside.
Thus, though rather astonishing
Maurels conclusion that the physiol
ogical zero Is lower than the surfac,
temperature cannot be attacked, ex
cept on the basis of new experiments
Literary Digest
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