An April Fools’ Origin
In April 1978, Kenneth Woolner of the University of Waterloo published an elaborate April Fools’ hoax in the chemistry teachers’ newsletter CHEM 13 News. He introduced Claude Émile Jean-Baptiste Litre, a supposedly 18th-century French scientist born in 1716, as the man behind the litre.
Why Claude Litre Was “Created”
The International System of Units typically uses capital letters for units named after people. Since “l” for litre could be confused with “1” or “I” in some fonts, Woolner jokingly solved the issue by inventing Claude Litre, justifying the capital “L.”
From Hoax to “History”
Woolner wrote a detailed fictional biography, claiming Litre was the son of a wine bottle maker who proposed a unit of volume that was adopted posthumously in 1778. The story was convincing enough that it was mistakenly printed as fact in the IUPAC journal Chemistry International before being retracted.
The Real Origin of the Litre
In truth, the word “litre” comes from the litron, an old French unit of dry volume. No Claude Litre ever existed. The uppercase “L” remains in use today in part because Woolner’s joke highlighted the need for a clearer symbol, and agencies like the U.S. NIST now recommend it.
Claude Emile Jean-Baptiste Litre was said to be the man behind the litre.
Except he wasn't.
In 1978, chemist Kenneth Woolner invented him for an April Fools' joke – to solve a typographic headache: how to justify a capital "L" for litre…🧵👇 pic.twitter.com/MTzABP55r2
— Fascinating True Stories (@FascinatingTrue) October 9, 2025