It’s a pretty well-known fact that that the Nazis financed their portion of World War II in part by seizing the gold reserves of the nations they conquered. It’s hard to know exactly how much gold was stolen by the Nazis: contemporary accounts are a confusing hodgepodge of metric, Imperial and troy units, and books on the subject don’t always make it clear whether they’re using historical or inflation-adjusted currencies. But it’s certain that the Nazis seized tons of gold throughout Europe and sent it back to Germany, where it was melted down and recast with the Nazi stamp.
What is less known, however, is that the Nazis also banned the export of gold from Germany in the 1930s. At the time, the German government faced the dual problem making reparation payments to the Allies while simultaneously (illegally) rebuilding their armed forces. What’s worse, any Jews, academics, intellectuals and leftists who could afford to leave Germany did, taking their gold with them. Germany’s gold reserves fell to unsustainably low levels, hence the law forbidding anyone to take gold out of the country.
Which made the actions of two German scientists – Max von Laue and James Franck – a crime. Both men had sent their Nobel Prizes to the Institute of Theoretical Physics in Copenhagen. The Institute’s founder and leader – Niels Bohr – promised to keep the medals safe for the men.

The only problem was the Germans launched the invasion of Denmark and Norway – Operation Weserübung – on April 9, 1940. The Danes held out for a whopping six hours before giving up, but there was method to their madness: in return for their quick surrender, the Nazis allowed the Danes a fair amount of autonomy, and Denmark was arguably the safest place to be in Nazi-occupied Europe.
But the Nazis did go door to door throughout Copenhagen, looking for gold, Jews or anything of interest to the Reich. Bohr knew the Nobel Prizes would be a death sentence for von Laue and Franck. After all, they were not only made of 23 karat gold – which was illegal to export – they also had the recipient’s names inconveniently inscribed on them. And von Laue was a vocal opponent of the Nazis and Franck was Jewish. If the Gestapo found the medals… it would be bad.
A Hungarian chemist named Georgy de Hevesy was working in Bohr’s lab that day. He suggested to Bohr that they bury the medals. Bohr rejected the idea, as it was only a matter of hours before the Nazis arrived, and they certainly would notice any recently disturbed dirt on campus grounds. So de Hevesy had another idea: there was a chemical in the lab, a mixture of three parts hydrochloric acid and one part nitric acid known as aqua regia. It has several uses in the lab and it’s one of the few chemicals that will dissolve gold. Perhaps they could just… dissolve the medals?
Bohr agreed, so the men put the Nobel Prizes in the aqua regia. The thing is, though, aqua regia breaks down gold slowly. Dissolving the medals might have taken days or even weeks! And so the two men spent several very nervous hours watching the medals ever so slowly dissolve. I imagine it was like a scene in a movie where the Good Guy copies a bunch of files to a flash drive while being hunted by the Bad Guys, and we all watch as the agonizingly slow progress bar tracks the copy: 20% complete… 30% complete… 40% complete. Only in real life this chemical process went on for hours and hours!








