in the same way.

_Organic matter in air._

The stuffy and close feeling perceived in an ill-ventilated room is,
however, due to the organic matter from the lungs, which is expired
along with the carbon dioxid, and some chemists have argued that this
amount of organic vapor ought to be measured instead of the carbon
dioxid.

At the present time there is no simple and direct method of measuring
organic vapor, and because this vapor increases in the atmosphere
proportionately to the carbon dioxid gas, it is much simpler to measure
the latter. Then it is impossible to fix a standard of carbon dioxid
because a person whose lungs are well developed and whose blood is well
oxygenated, or, as we say, one who has good red blood can stand, even if
uncomfortable, a few hours of a bad atmosphere without suffering serious
discomfort, while an anaemic or poor-blooded person would be affected to
a greater degree. It is for this reason that in any house no living
room, especially one heated by a coal stove, should be shut up tight
against fresh air. This is the reason why the women of the family, who
have to breathe the same air over and over all day, are pale and weak
and easily susceptible to disease, while the men, who are out of doors
most of the time, and when indoors are made restless by the bad air,
suffer much less from the ill effects.

Experiments seem to show that when the amount of carbon dioxid in the
air has doubled, that is, when the expired air mixed with the air in the
room has increased the proportion of carbon acid from four parts in ten
thousand to eight parts in ten thousand, that the air is seriously
affected, and that such ventilation ought to be provided that no greater
amount than this could occur. This is such a condition that the room
smells "close" or stuffy to a person coming in from outdoors, indicating
organic emanations as well as an excess of carbonic acid gas. The
question then is: how may this condition be avoided in an ordinary
house, or in an ordinary stable, because the health of the cattle on a
farm, judging at least by the character of the buildings provided, is
quite as important as the health of the farmer's family.

We must take it for granted that no such elaborate schemes are possible
as in public buildings or schools, where fans are provided, either to
force air into the several rooms or else to suck it out. The ventilation
of the house must be more simple and easily adjusted and mus