ter sufficient air had been breathed into the jar.
Clearly, then, he argued, air once breathed is not suitable for
respiration, unless much diluted with pure air. He argued from this that
if a candle using oxygen for combustion could not burn in expired air,
therefore an individual using oxygen for the renewal of the blood could
not be properly supplied in a room partially saturated with the expired
products of the lungs.

Professor King also experimented with a candle burning in a jar on which
the cover had been placed, and found that the candle was extinguished in
thirty seconds, and he argued that if a candle was thus extinguished on
account of the carbonic acid given off, so a person shut up in an
air-tight chamber would similarly be extinguished in the course of
time.

To prove that expired air is poisonous to animal life, Professor King
experimented on a hen, placing the same in a cylindrical metal air-tight
chamber eighteen inches in diameter and twenty inches deep. The hen
became severely distressed for want of ventilation and died at the end
of four hours and seventeen minutes.

In the Wisconsin Agricultural Experimental Station, an experiment was
conducted for fourteen days on the effect of ample and deficient
ventilation on a herd of cows. The stable was chiefly underground and
had two large ventilators which could be opened or closed at will. The
food eaten, the water drunk, the milk produced, and weight of the cows
were recorded each day. For a part of the time the cows were kept
continuously in the stable with all openings closed, and then the
ventilators were opened, the alternate conditions being repeated at
intervals of four days. The amount of food consumed was practically the
same under both conditions. The quantity of milk given was greater with
good ventilation. The chief difference was in the amount of water
consumed, since with the insufficient ventilation the cows drank on the
average 11.4 pounds more water each, daily, and yet lost in weight 10.7
pounds at the end of each two-day period. Examination of the animals
themselves also showed that a rash had developed on their bodies which
could be felt by the hand and which was apparently very irritating,
since it was so rubbed by the animals as to cause the surface to bleed.
The evident teaching of the experiment is that under conditions of poor
ventilation, it was impossible for the lungs to remove waste products to
as great an extent as usual,