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 17th
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).
_____
The illustration above is actually from the 1738 edition of Becher.
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