On the Under- , Partial and Full Discoveries of Oxygen

JF Ptak Science Books LLC  Post 574

Our sea of air is composed of atoms, and the atoms are mostly nitrogen (78%) and oxygen (21%), and the atoms are of course all around us; though as obvious as it is, as present as it is, the most active component of air, oxygen, remained under-discovered until relatively late in human history.  Oxygen is present in all major classes of structural molecules in living organisms and in all manner of inorganic compounds, and is   When it was discovered, it really wasn’t; or it wasn’t discovered and recognized until the second time around.  But the stuff that was whirling around its near discoveries were important in themselves for their constituent parts. 

Johann Joachim Becher (born in 1635 and dead at 47 in 1682) got part of the way there, though he didn’t discover oxygen—he discovered the thing that oxygen wasn’t:  phlogiston.  But the phlogiston theory worked a little, but not a lot.  The theory appeared in his book Physica subterranean profundam subterraneorum genesin e principiis bucusque ignotis…and was published in 1669. (Actually, his Subterranean book was published just a few years after our old friend Athanasius Kircher’s masterpiece Mundus Subterreaneus. Just a tired note from the small-world category.)  Actually what the phlogiston theory “did” was explain the process of fire and oxidation—phlogiston was the colorless/odorless/undetectable stuff that was released from the combustibles of the four elements of the Greeks when they rusted or caught on fire. Once the phlogiston was released, the true nature of the material that once held it was then revealed.  As James Conant wrote in. The Overthrow of Phlogiston Theory: The Chemical Revolution of 1775–1789. Cambridge : Harvard University Press (1950, page 14):

“…in general, substances that burned in air were said to be rich in phlogiston; the fact that combustion soon ceased in an enclosed space was taken as clear-cut evidence that air had the capacity to absorb only a definite amount of phlogiston. When air had become completely phlogisticated it would no longer serve to support combustion of any material, nor would a metal heated in it yield a calx; nor could phlogisticated air support life, for the role of air in respiration was to remove the phlogiston from the body."

The other thing that happened was that the phlogiston released into the air could not on its own support life.  That meant it wasn’t not oxygen, it was the opposite of oxygen:  anti-oxygen.  Anti-oxygen is an interesting, very science fiction-y topic, a very cool brick for  the edifice of contracting imaginary worlds.  But in the world of the late 17^th century and for another hundred years, it as the material of theory. 

Becber’s Physica was actually not that at all, either:  it was a work on chemistry, and alchemy, and addressed itself too to the positive possibilities of transmutation.  On the other hand, Becher was the very first to attempt to construct a theory of chemistry.  As stated by Thompson in his history of chemistry:  “(Becher) was the first person who can with propriety be said to have attempted to construct a theory of chemistry; Boyle, who was responsible for hastening the downfall of alchemical and other onions, did not attempt to set out (such a theory)…”

Joseph Priestly on the other hand did actually discover oxygen in 1774—or at the very least was the first to get into print about the discovery, establishing priority over  Carl Wilhelm Scheele who seems to have discovered oxygen first in 1773 but was second in print on the matter--but he couldn’t believe his own results enough to dislodge phlogiston, and went to his grave an unredeemed phlogistonist. ((I admit to being pretty flippant here, as Priestly was an enormously talented man, at high rank in part of the great panoply of scientists; he was also a great political observer and pamphleteer who paid dearly  for his morality.)  It took Antoine Lavoisier’s beautiful experiment in 1777 that established the work of Priestly and Boyle beyond question, killing phlogiston once and for all.  As a matter of fact Lavoisier also published his account along with a general treatise on chemistry in his Traité élémentaire de chemie—a book that looks remarkably fresh for being printed in 1789—completely it at age 47, just four years before he was guillotined for being seen as an enemy to the people of France.  But that (along with the exceptional Mme. Lavoisier, is another story). 

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The illustration above is actually from the 1738 edition of Becher.