The Jackson standard. [volume] (Jackson C.H., Ohio) 1847-1888, 1875-03-11
of the Scientific American
The Principles of Ventilation.

Unless I greatly mistake the intelli-
gence and disposition of the average
American, his Scientific" representative
will be deluged with articles protesting
against the crude notions contained in
the article coming from "the land of
cakes" entitled 1.-The Ventilation of the
United States Senate Chamber" l pur-
posely ignore the special subject of his
article, the senate chamber, and beg
leave to refer very briefly to some of the
most untenable of his general assertions.
He boldly asserts that "the whole Sc
cret of ventilation consists" in providing
IAN entrance for fresh air below and an
exit for foul air above" and bases this
erroneous idea upon the false assump-
ton that foul air" making no distinc
tions, "ascends and accumulates at the
ceiling" only. He also says: "If our
halls like the ancient Greek houses, were
without roofs, ventilation would cause
no thought" for 1.-The foul air from our
lungs and bodies would ascend right into
the air, and fresh supply would come
down to US through the same opening"
AS simple and plain refutation of his
statement regarding the tendency of foul
air to accumulate at the ceiling" 1
would refer him to the familiar expert
ment OF placing bit of lighted candle
at the bottom of a tall glass jar with open
top He will find, upon exhausting the
lungs into the bottom of the jar, by
means of tube that the light will be
extinguished almost Immediately; and
if he breathe downward into the jar-not
directly over the fame, but near the side
of the vessel-the light will just as cer-
tainly be put out as in the previous ex-
pertinent, only the inevitable and fatal
result will be retarded. If, instead of
the lighted candle in the tall jar, he pla-
ces "the ancient Greeks" or a few live
Scotsmen in a "high" room, closed at the
bottom and open to the free air of heaven
at the top, he will find results quite par
allel to those in his previous experiments.
Any causes favoring the sudden genera-
tion of an excessive amount of oarbonic
acid gas would result in speedy death to
them all, or in asphyxia, as in the first
experiment, Confinement in the same
place, under more favorable circumstan-
oes, would somewhat retard the fatal re-
suit; but ultimately, as the air became
contaminated by poisonous exhalations,
languor, decay, and death by some
chronic malady, would occur as surely
as the light was slowly extinguished in
the second experiment,
In both these instances, "the destroy
ing angel" is carbonic acid; it is the prin-
clpaI QeIeterlOuS element which contain
mates the air we breathe, and to which
we are most universally exposed; it is
generated by decomposition, by combus-
ton, and by respiration. At any ordi-
nary comfortable living temperature, the
specific gravity of this poisonous gas,
even when exhaled from the lungs, is
greater than that of the surrounding air;
therefore it of necessity gravitates to the
bottom of the jar or to the bottom of q
room, instead of rising to- the ceiling.
No matter what may be its source, if in
excess it Is "the destroying angel al
ways injurious, often fatal. We find, in
what is called pure air, about As parts of
oarbonic acid to 10000 of air; the open
air of cities is often contaminated by
from 6 to Is parts to 10000 while the
confined air of some public halls and
school rooms has been found to contain
as many as IS parts to 10000, in such
cases rendering the air absolutely poison
ous
If warming were not inseparably con-
nected with proper ventilation, as, I'M
fortunately for the position of your cor
respondent, it is in our climate, it might
do to provide only for the escape of foul