Since the discovery of oxygen, there have been swings from emphasis on the
essential, beneficial nature of oxygen to focus on its damaging effects. Outright
speculations and critically-considered hypotheses have ebbed and waned for the
therapeutic use of elevated oxygen and practical applications of gas mixtures for deepsea
diving and pressurized caissons for construction under water. Oxygen as therapy
has been proposed as beneficial or even a panacea. In some hands it was harmful and
even deadly. The use of elevated oxygen tensions (as compressed air) began even
before oxygen was isolated and identified from air. Oxygen was used as therapy and
compressed air was extensively breathed by miners and workers in caissons tunneling
under water to construct bridges. These practical, non-therapeutic applications of
various breathing mixtures containing oxygen also contributed to scientific
understanding of the physiology of oxygen in the human body. Elevated oxygen
tensions also were used for U.S. Navy diving operations and laboratory experiments
with humans and a variety of life forms. In the early years oxygen therapy was used for
a wide variety of diseases, many of which were treated without any established
connection to a mechanism of action. Thus, the therapeutic use, laboratory
experimentation with, and practical applications of compressed air, gas mixtures at and
below one atmosphere pressure, and hyperbaric oxygen has had an interesting, long,
and colorful development that included charlatans (probably), adventuresome
physicians ahead of their times, visionaries, and practical men of industry.
Keywords: Air embolism, Albert Behnke, Atmospheric pressure, Caisson,
Carbon monoxide poisoning, CNS toxicity, Compound oxygen, Cunningham,
Decompression sickness, Domicilium, Gas gangrene, Henshaw, Hyperbaric
pressure, John Bean, John Haldane, Lorrain Smith effect, Paracelsus, Paul Bert
effect, Pulmonary toxicity, Spanish flu treatment, USS Squalus.
