Raftsman's journal. [volume] (Clearfield, Pa.) 1854-1948, 1857-10-07
AIR AND ITS USE.

The pressure of atmosphere on the body of
a medium-sized man is equal to a weight of
10000 lbs., which were it not resisted by an
equal atmosphere from within, would instantly
crush the strongest frame into atoms. One
pound of air measures about 49, cubic feet.
a room feet high, II wide, and I3 long,
contains about 100 lbs. of air and a room
40 feet square and Is feet high contains about
tun. But the pressure of air on the body is
not the same at all times. Every alteration
of an inch in the mercury of the barometer
adds or removes a weight of ,0S0 from the
average weight which man of common stature
sustains. The effects of sudden change in
the atmospheric pressure are often shown in
the shape of headache and apoplexy. The
Impurities of the atmosphere are the secret
cause of great variety of diseases. The
decay of organic matter, vegetable and animal,
generates numerous substances which are pre-
Judicial to health. The air is the grand reser-
voir into which all volatile matters escape,
many of them bearing the principles of con-
tagion and pestilencc. Butwe are not without
the means of avoiding this danger. The
salubrity Of the air is promoted by elevation.
The open hilltop insures atmospheric purity
in ordinary cases. \ rise of sixteen feet
within three hundred yards has been known to
produce an entire change from a relaxing to
a bracing air. The common belief is correct
that night-air is less heathful than that of
day. Tropical fevers are most fatal in the
night. Yet the miasma which produces them
is generated with the greatest rapidity during
the intense heat of the sun. The reason of
this is easily explained. In the daytime,
the air, heated by contact with the burn
ing ground, expands and rises in an upward
current, thus diluting and carrying away
veloped. But at night, in the absence of So
lar heat, no such force is at work, and the
miasms are, accumulated and condensed in
the lower strata of the atmosphere. Hence,
the upper stories of house are less exposed
than the ground-foor, and are more eligible
for sleeping chambers. During the preva-
lence of the yellow fever in Philadelphia,
those who occupied apartments in the third
story were far less liable to attack than those
who resided lower. Sleeping in low rooms
is probably worse in the city than in the coun-
try.
The atmosphere contains the means of pu-
rfcation within itself. When noxious exhal-
ations are set free, they are diffused through
the vast volume of the air, and by the law of
gaseous expansion, aided by the winds and
storms, are lost in the universal intermiXture.
Oxygen finally acts upon them, and burns
them up as completely as if they had been
consumed in a furnace. There the causes of
impurity are confined. The air loses large
proportion of its oxygen by being breathed,
and receives an equal quantity of poisonous
carbonic acid by the same process. The bur-
ming of fuel and combustion for light produce
the same effect. Air-tight stoves and bot-air
furnaces are especially Objectionable on this
account. Gaseous exhalations of pernicious
Quality escape from the kitchen. The discol-
orations of white walls shows that the air has
been contaminated by poisonous sulphuretted
hydrogen. In this case, the sulphur combines
the white lead, and forms black sulphuret of
lead. White zinc paint is not liable to this
change, and hence offords no indication of the
state of the atmosphere. Nor is it true, ac-
cording to the popular belief, that cold air is
necessarily pure, and that apartments need
less ventilation in Winter than in Summer.
Green paper hangings are also dangerous, and
when colored with certain pigments exhale
deadly, poisonous vapors. Cellers are often
sources of disease, and, when filled with de-
caying vegetables, generate noxious air Of
the most fatal character, although SLOW in its
operation, by reasons of the small quantities
in which it reaches the occupants of the upper
apartments.