potash

For centuries, European farmers and soapmakers produced potash by burning wood, soaking the ashes in water, and boiling the solution in iron pots until a white salt crystallized. Pot ash. The name is that literal. This crude potassium carbonate was essential for making soap, glass, and gunpowder. Colonial America exported vast quantities of it to England — potash was so valuable that it was the first patent ever issued by the United States, in 1790.

The chemical symbol K tells a parallel story. It comes from kalium, the Latinized form of Arabic qalī (قلي), meaning 'ashes of plants.' Arab alchemists had identified the alkaline substance in plant ashes centuries before Europeans named the element. The word alkali itself is al-qalī — 'the ashes.' Potassium's very identity is split between an English kitchen and an Arab laboratory.

Humphry Davy isolated potassium on October 6, 1807, by running electric current through molten potash. His laboratory notebook records that when the first globules of pure potassium appeared, he danced around the room in joy. He isolated sodium days later using the same technique. Davy was 29 years old and had just discovered two elements in a single week.

The naming war that followed has never been resolved. English kept potassium from pot-ash. German and most other languages adopted Kalium from the Arabic. The periodic table sided with the Arabs — K, not P or Po. Every chemistry classroom in the world displays the compromise: an English name with an Arabic initial, two civilizations sharing credit for the same white salt scraped from the bottom of a pot.