The creation and use of artificial oxygen atmospheres is of extremely recent origin by evolutionary standards. Indeed, the capacity of organisms to adapt to artificial oxygen atmospheres is constrained by the fact that extreme concentration exposures are artificial, usually acute and abrupt, mostly post-reproductive, and ultimately unsustainable for long periods of time. Much as wood cannot evolve protections against intense thermal injury (burning), eucaryotic cells have not evolved — and possibly cannot evolve unequivocally — to withstand even short term, serious oxidative injuries induced by extreme oxygen exposures.
While the word “oxygen” dates to the 18th C, knowledge about oxygen’s production and properties dates to the 8th C or earlier.* Credit for oxygen’s “discovery” should not be ascribed to any one person, place, or time but regarded as a metaphor based in fact for how we come to know what we know — and may still come to know in the future.
Chinese experimenters recognized as early as the 8th C that a substance released by heating potassium nitrate could react with carbon and sulfur but not gold. Italian scientist, artist, and inventor Leonardo da Vinci (1452-1519) postulated in the 15th C that air consisted of two parts: one consumed by burning and one not, corresponding to oxygen and nitrogen, respectively. Polish alchemist Michael Sendivogius Polonos (1566-1636) postulated in the early 1600s that an “areal food of life” circulated from earth to air via the same potassium nitrate — saltpeter — pathway that, when heated, released the “Elixir of Life.” His concept was put to a practical test in 1621 when a Dutchman, Cornelius Drebbel (1572-1633), created the first known artificial oxygen atmosphere, one capable of sustaining 12 men who remained submerged under water in a wooden submarine for three hours.
John Mayow (1641-1679, English), who studied respiration and physiology at Oxford in the 17th C, conducted a series of experiments that shed light on the properties and nature of oxygen. He probably deserves more credit than he typically receives for his work in this empirical domain. His experiments showed that select metals increased in weight when heated in the presence of his mysterious gas; that this marvelous and wondrous gas composed about 20% of the atmosphere; and that mice kept under a bell jar in the presence of a burning candle expired soon after the candle extinguished presumably because this gas was exhausted. These observations led him to conclude that spiritus nitro-aereus — oxygen by another name — was present in the atmosphere, transfered via the lungs to the blood by breathing, and consumed in respiration so as to sustain life itself.
Other curious and intrepid proto-chemists produced the “release of oxygen” by heating various metals: Ole Borch (1626-1690, Denmark) in 1678 (saltpeter), Steven Hales (1677-1761, England) in 1731 (saltpeter), Pierre Bayen (1725-1798, France) in 1774 (mercury oxide). However, there are three names most commonly cited in connection to the isolation, characterization, and naming of oxygen, fairly or not: Carl Wilhelm Scheele (1742-1786, Swedish), Joseph Priestly (1733-1804, English), and Antoine Lavoisier (1743-1794, French). Perhaps the improved communication flow and revolutionary spirit abounding in the 18th C explains why these three scientists typically receive credit for things predecessors also accomplished in some form.
Scheele isolated oxygen from various nitrates; Priestly isolated “deflogisticated air” from mercuric oxide using sunlight as a heat source and essentially replicated Mayow’s work with bell jars, mice, and candles — with the added feature of breathing the gas himself to see how it made him feel; while Lavoisier conducted derivative investigations but ultimately gave oxygen its name, after the Greek for “acid-former,” under the misconception that anything acting like an acid had to contain oxygen.
While all three deserve credit for experiments, reports in letters, and formal publications; Lavoisier is the one who campaigned most actively to gather fame to himself for the discovery of oxygen. Beheaded during the French Revolution, he nonetheless claimed: “This theory [the oxygen theory] is not as I have heard it described, that of the French chemists (e.g, Bayen), it is mine (elle est la mienne); it is a property which I claim from my contemporaries and from posterity.”**
It was not long after Priestly published “Experiments and Observations on Different Kinds of Air” (1775) that the therapeutic potential of oxygen to treat various respiratory conditions and unrelated diseases was recognized and exploited. The first commercial use of artificial oxygen atmospheres for medical purposes was initiated by Thomas Beddoes (1760-1808) at his Pneumatic Institute in Bristol, England in 1798. This short-lived enterprise shut down in 1802. Of great interest is the fact that Humphry Davy (1778-1829, England) of nitrous oxide fame; and James Watt (1736-1819) of steam engine fame were partners with Beddoes in his enterprise — one which, practically speaking, upended the tight relationship between evolution and atmospheric oxygen content; while changing forever the way medicine would view and handle oxygen therapy in patient care settings.
*Technically minded readers might enjoy reading or reviewing:
Lane N. Oxygen. The Module that made the World. Oxford, 2002
Stępniewski W, Stępniewska Z, Bennicelli RP, Gliński J. Oxygenology in Outline. Institute of Agrophysics PAS, Lublin, 2005
http://www.chemistryexplained.com/elements/L-P/Oxygen.html
**http://todayinsci.com/
