the lake, and
discharged its sewage into the same lake only a few feet away from the
water intake. That the hotel had a reputation of being unhealthy, and
that it had difficulty in filling its guest rooms, is not to be wondered
at, and yet individuals will treat their lungs exactly as the hotel
treated its patrons.

_Effects of bad air._

In order to establish a proper relation between the amount of impurities
diffused through the air and the physiological effect on individuals
breathing that air, certain observations have been noted and certain
experiments have been made which prove without question the injurious
effect of vitiated air.

Professor Jacob, late Professor of Pathology, Yorkshire College, Leeds,
gives the following example on a large scale, to show the results of
insufficient ventilation: "A great politician was expected to make an
important speech. As there was no room of sufficient dimensions
available in the town, a large courtyard, surrounded with buildings, was
temporarily roofed over, some space being left under the eaves for
ventilation. Long before the appointed time several thousand people
assembled, and in due course the meeting began; but before the speaker
got well into his subject, there arose from the vast multitude a cry for
air, numbers of people were fainting, and every one felt oppressed and
well-nigh stifled. It was only after some active persons had climbed on
the roof and forcibly torn off the boards for a space about twenty feet
square that the business of the meeting could be resumed."

Remembering that the process of breathing is for the purpose of
supplying oxygen to the blood and that the absorption of oxygen in the
lungs is the same process which goes on when a candle burns, the
following experiments were made by Professor King of the University of
Wisconsin, to show the effect of expired air on a candle flame. He took
a two-quart mason jar and lowered a lighted candle to the bottom, noting
that the candle burned with scarcely diminished intensity. Through a
rubber tube, he breathed gently into the bottom of the jar, with the
result that the candle gradually had a reduced flame and was finally
extinguished. He observed also that if the candle were raised as the
flame showed signs of going out, the brilliancy of the flame was
restored, while lowering the candle tended to extinguish the flame. Even
when the candle was raised to the top of the jar, the flame was
extinguished af