In a Word: Thank Goodness for ‘Oxygen’

Managing editor and logophile Andy Hollandbeck reveals the sometimes surprising roots of common English words and phrases. Remember: Etymology tells us where a word comes from, but not what it means today.

Except for the fact that it’s based on a misunderstanding of the element’s properties, the etymology of the word oxygen is neither exciting nor terribly surprising. But the story of how it came to be and the word it replaced — a word you only hear in spelling bees today — is an interesting one.

Before the invention of microscopes powerful enough to reveal the microscopic, scientists formed sometimes complicated theories to explain commonplace occurrences. Fire, for example, was a tough one — what was fire, and why did some things burn more easily and quickly than others?

By the 18th century, the most accepted explanation of fire was phlogiston theory. According to this theory, nearly all substances contained an essence called phlogiston (from the Greek phlox “flame”). When a substance was set on fire, the flame was actually the phlogiston being released and then absorbed by the surround air.

Scientists noticed that when you put a flame in a sealed container, it would eventually burn out. They theorized, then, that air could absorb only a certain amount of phlogiston, and once the air was completely saturated — phlogisticated in the scientific parlance — the burning substance could no longer release its phlogiston.

In 1774, English polymath Joseph Priestley proved that the air we breathe is not a single elementary substance but a mixture of gases, and one of the gases he discovered was crucial for the presence of flame. He believed he had found the substance in the air that absorbed the phlogiston and that was therefore responsible for the existence of flame. Because it had yet to absorb any phlogiston, he called this substance dephlogisticated air.

Luckily for us, at about the same time, French chemist Antoine-Laurent Lavoisier discovered the same element and began studies that ultimately disproved phlogiston theory. He called the element oxygène — from the Greek oxys “acid” and the French ending -gène “something that produces” — because he believed it was essential for the formation of acids. In English, it became oxygen.

Lavoisier was wrong about the link between oxygen and acids, but while oxygen isn’t etymologically the most accurate name to describe the element that keeps us breathing, it’s still loads better than the seven syllables of dephlogisticated air.