The home journal. (Winchester, Tenn.) 1858-188?, 1873-10-09
Relation of the Air to Clothing.

The following statements Of general
interest are specially reliable, beingcon-
tanned in a lecture by Professor Petten-
kofer, Of Munich, who is known as high
authority on such subjects Although
the warmth of the body is the result Of
respiration, it is q singular fact that the
normal temperature of the blood Of TIE
African is the same as that Of the Esqu'
max, or about 800 degrees, while the Dir
surrounding them, and inhaledby them,
may differ az much as 1870 degrees IN
temperature ; neither does this temper
ature vary, in a state OF health, more
than two degrees, though the tempera-
ture of the airmay vary u deg. Theheat
generated by the body in twenty-forr
hours is sufficient to raise thirty quarts
of cold water to the boiIipg-point and
OF this the regular processes Of nutri-
ton require only a definite part, ana the
larger portion must be giveno off Through
radiation, evaporation, or condnctiou.
When heat is lost by radiation, as inst
ting near a cold window, or other cold
object, the impression Of adrangbt may
be created, although the mir beperfectly
calm, heat being simply given up to the
colder object. Thus, while tho tenn
perature Of n room may remain con
slant, different sensations may be eXpc-
rienced, dependent on the surrounding
objects. A much larger amount Of the
superauous heat is lost by evaporation;
and during severe exercise, when more
heat is developed, evaporation is also
more rapid, and tho normal temperature
Of the blood restored. A "cold" is
caught when the evaporation istoorapId.
But little heat il lost by conduction.
The particles OF mir in contact with the
body becomes warm, and arereplacedby
colder ones, creating a current, which is
insensible, because of loss velocity than
three feet per second. In better con
ductors coolingta takes place more rapidly,
water Of 81 degreesseeming muchcoldcr
than air of 81 degrees. These three
modes of cooling, however, supplement
each other, and act together. Thus =
current of warm mir cools more rapidly
than calm cooler air, not only by reason
Of renewal of the air, but by fayoring
evaporation.
The chief object Of clothing is tosur-
round the body artilioially with n warm
climate, poor conductors being consc-
quently selected. Tho cooling process
is, however, simply checked by the cloth
ing. Even the thinnest, iincstfabric, aa
u veil, diminishGs loss byradiation. But
the inclosurc Of mir IL especially eHec-
tive, and consequently garments Of po-
rous heavy material are warmer than
those which are more compact. Felt
shoes, pormeablo to air, are wnrmcrtha n
leather or ipd%ia-rubbor ones, while the
latter soon become uncomfortable because
Of checked ventilation. The more hy-
~grocopic tho material, the colder the
clothing, because it il n better cOnduC-
tor when moist. Linen and silk are for
this reason colder than wool, and also be
cause the latter retains It's elasticity when
moist, and keeps the mir within lLsporcs.
And our bed, which is, in fact, orr sleep
ing garment, is of special interest. IT
must be warmer than our waking cloth
ing, since less heat il developed during
sleep. Consequently loss Of sleep is
very exhausting. The feathC r-bed pos
aossos in the highest degree feeble con
Quoting power, elasticity, and pennea,
bility to air; but, if too thick or soft,
resembles more al air-tight garment.
The house, too, may be regarded Ms IN
extended piece Of clothing, sograduaI is
the transitiop from bodily garments toit
the step from the wide garment Of the
Arab 10 his felt tent being a small one,)
and, in hygienic functions, they agree
precisely ~inregulating our relations with
the surronndingair. Theease with which
n current of air may be blown through
n brick, pieces of mortar, wood, etc, by
glass tubes cemented TO opposite sides,
md the passage of water $50 much den
SER through these substances, show how
inperfectly our walls, Of whatever ma.
terial, and however thick, exclude the
mir from us. We do not perceive tho
FREQ passage of mir through them be-
cause the currents too slow. Hupcr's
Dfaga=inc.