Culmination of Fulmination

Mercury fulminate

German chemists recently determined the crystal structure of a compound the alchemists knew as “Knallquecksilber”, but which goes by the formal name of mercury(II) fulminate. The compound is highly explosive, sensitive to heat and shock and its control in the form of a detonator material for dynamite gave Alfred Nobel his big break.

The new crystal structure corrects some previous mentions in the scientific literature, by revealing it to be an almost linear molecule. But, never mind the chemistry you can read more about that in the September issue of my Intute Spotlight. It is that name that intrigues me. Knallquecksilber.

Quite literally it means “bang quicksilver”, quicksilver being silvery mercury’s liquid alchemical name. Bang quicksilver hardly slips off the tongue, so a better translation might be exposive quicksilver, which isn’t quite so crisp and subtle as the German word, but close.

I had a chat with a German chemist friend about the etymology of this name and the lack of a subtle literal translation from the German into English. It’s common to quite a few German words, zeitgeist, meaning literally time-ghost or spirit of the times, being another favourite. My friend pointed out that knallen (verb) describes something exploding with a big bang, a
Knall, the crack of a whip or the banging of a door might be described using knallen in German, for instance.

But, he also pointed out that the English name for this salt itself – mercury fulminate – harbours an explosive origin. Fulmination, of course, being another word for a violent explosion and so perfectly apt for describing big bang quicksilver.