The Bolivar bulletin. [volume] (Bolivar, Hardeman County, Tenn.) 1865-1888, 1873-10-03
Relation of the Air to olOthing.


The following statements of general
interest are specially reliable, beingcon-
tanned in a lecture by Professor Petten-
kofer, of Munich, whs is known as high
authority on such subjects Although
the warmth of the body is the result of
respiration, it is singular fact that the
normal temperature of the blood of the
African is the same as that of the Esqui-
max, or about 993 degrees, while the air
surrounding them, and inhaled by them,
may differ as much as $50 degrees in
temperature neither does this temper
ature vary, in a state of health, more
than two degrees, though the tempera-
ture of the air may vary p deg. Thehea
generated by the body in twenty-fOur
hours is sufficient to raise thirty quarts
of cold water to the boiling-point and
of this the regular processes of nutri-
ton require only a definite part, and the
larger portion must be given off through
radiation, evaporation, or cOnduction.
When heat is lost by radiation, as insit-
object, the impression of a draught may
be created, although the air beperfectly
calm, heat being simply given up to the
colder object. Thus, while the tenn
perature of a room may remain con-
slant, different sensations may be expe-
rieneed, dependent on the surrounding
objects. A much larger amount of the
superfuous heat is lost by evaporation );
and during severe exercise, when more
heat is developed, evaporation is also
more rapid, and the normal temperature
of the blood restored. A "cold" is
caught when the evaporation is toorapid
But little heat is lost by conduction.
The particles of air in contact with the
body becomes warm, and arereplacedb by
colder ones, creating a current, which is
insensible, because of less velocity than
three feet per second. In better con-
ductors cooling takes place more rapidly,
water of 81 deg. ees seeming much colder
than air of 81 degrees. These three
modes of cooling, however, supplement
each other, and act together. Thus Q
current of warm air cools more rapidly
than calm cooler air, not only by reason
of renewal of the air, but by faVOring
evaporation.
The chief object of clothing is to sur
round the body artifcially with a warm
climate, poor conductors being conse-
quently selected. The cooling process
is, however, simply checked by the cloth
ing. Even the thinnest, finest fabric, as
a veil, diminishes loss byradiation. But
the inclosure of air is especially efec
tive, and consequently garments of pc
rous heavy material are warmer thar
those which are more compact. Fell
shoes, permeabIe to air, are warmer thar
leather or india-rubber ones, while the
latter soon become uncomfortable because
of checked ventilation. The more by
groscopic the material, the colder the
clothing, because it is a better conduc
tor when moist. Linen and silk are TO
this reason colder than wool, and also be
cause the latterretainsitse elasticity whel
moist, and keeps the air Within it's pores
And our bed, which is, in fact, our sleep
ing garment, is of special interest. I
must be warmer than our waking cloth
ing, since less heat is developed durin;
sleep. Consequently loss of sleep i
very exhausting. The feathcr-bed pos
sesses in ne highest degree feeble con
Quoting power, elasticity, and permea
bility to air; but, if too thick or soft
resembles more an air-tight garment
The house, too, may be regarded as al
extended piece of clothing, so gradual i
the transition from bodily garments tot
(the step from the wide garment of tn
Arab to his felt tent being a small one,
and, in hygienic functions, they agre
precisely inregulating our relations wit
the surroundingair. The ease with whic
current of air may be blown throug
brick, pieces of mortar, wood, ETC., b
glass tubes cemented to opposite sides
and the passage of water $50 much den
ser through these substances, show no
inperfectly our walls, of whatever mi
terial, and however thick, exclude til
air from us. We do not perceive tn
free passage of air through them bt
cause the current is too Harper.
N1d0zig7e