Hello, friends! Welcome to Sciency Words, a special series here on Planet Pailly where we take a closer look at the definitions and etymologies of scientific terms. Today on Sciency Words, we’re talking about:
Earth. Fire. Air. Water. Only the Avatar can master all four elements. Only the Avatar… or Antione-Laurent Lavoisier, the 18th Century French chemist. As described in this article, Lavoisier originally intended to study each of the four elements in turn, starting with air. But Lavoisier’s air research quickly “bent” the concept of the four elements so hard that the whole concept broke. And thus…
Lavoisier did not discover oxygen, but he did name it. You see, when oxygen was first discovered in the early 1770’s, it was called “dephlogisticated air.” That’s a mouthful of a name, but it made perfect sense to anyone who was familiar with the phlogiston theory of combustion.
Now I’m not going to waste your time explaining what phlogiston theory was, except to tell you that it was an updated-for-the-18th-Century version of the theory that fire is an element. The important thing to know is that Lavoisier’s experiments on dephlogisticated air poked some pretty big holes in phlogiston theory, and so that theory had to be abandoned in favor of “oxygen theory.”
So where did the word oxygen come from? Let me try to reconstruct Lavoisier’s thought process. Among other things, Lavoisier found that burning stuff in “dephlogisticated air” tended to produce substances that were more acidic than the original reactants. “Oxy” is Greek for acid. So some sort of acid-generating process was occurring… an “oxy-genesis,” if you will. Or “oxy-gen” for short!
The term Lavoisier actually used was principe oxygéne, meaning “the acidifying principle.” The words oxygen and oxidation start appearing in English shortly thereafter, thanks mainly to translations of Lavoisier’s work. But by that point, it was clear that oxygen was more than merely an acid-generating gas. It had other properties too. Lavoisier demonstrated that oxygen played an important role in both combustion and animal respiration, as well as other natural processes like the rusting of iron.
But we’ll talk more about oxygen’s many abilities in next week’s episode of Sciency Words.
P.S.: Lavoisier also named hydrogen. Burning “inflammable air” and “dephlogisticated air” together produced water. “Hydro” is Greek for water. So some sort of water-generating process was occurring… a “hydro-genesis,” if you will. Or “hydro-gen” for short!
P.P.S.: And since you can make water by mixing two different kinds of air, water must not be an element. Also, how can air truly be an element if there are different kinds of air? This whole four elements thing fell apart pretty quickly as Lavoisier continued his research.