Attention has been called to some curious effects of rarefied
and of condensed air on human respiration. On high mountains
some persons experience distressing shortness of breath, one
result of which is that they are unable to whistle. Precisely
the same effect is sometimes produced by the condensed air in
caissons and diving-bells. Laborers working in comprest air
frequently find, however, that their powers of exertion are
increased as long as the atmospheric pressure is not more than
double that of ordinary air; but beyond that point unpleasant
effects are experienced after the men have left the working
shafts and returned into the open air. On the other hand, high
atmospheric pressure in the case of persons not doing manual
labor has been found to act as a mental stimulus, increasing the
impulse to talk.--_Harper’s Weekly._
(61)
=Air of Sea as Purifier=--See PURIFICATION.
=Airship Flight=--See AMBITION.