Danish physicist Niels Bohr (pictured below) was a noted anti-Nazi crusader and assisted various Jewish scientists and other refugees who were being persecuted by the Third Reich.
Nobel laureates James Franck (a Jewish physicist) and Max von Laue (an outspoken critic of Hitler) were Germans who were concerned in the 1930s that their gold Nobel Prize medals would be seized by the government. They smuggled them to Bohr in Denmark for safekeeping. In doing so, they violated a German law prohibiting the export of gold out of Germany.
Unfortunately, the Germans invaded Denmark in 1940. Bohr realized that his reputation as a Jewish sympathizer would put his house and laboratory at the top of the Nazi "Places to Search Today" list. Were the Germans to discover in Bohr's custody the Nobel medals with the names of the recipients engraved on them, Bohr and the two German Nobel laureates would all pay the ultimate price for their outrageous auric audacity.
Hungarian physicist George de Hevesy was working in Bohr's lab at the time. He took the two Nobel medals and placed them in aqua regia, which is one of the few solutions which can dissolve gold. Unfortunately, it is a very slow chemical reaction, and de Hevesy and Bohr spent several nervous hours watching the gold slowly disappear while waiting for the sound of jackbooted footfalls.
The footfalls finally did arrive, but by the time they did so, all that remained of the medals was a bottle of innocuous orange liquid. The Nazis left empty-handed, and the bottle of dissolved gold remained on Bohr's shelf until after the war.
In 1950, de Hevesy reversed the chemical process and gave the resulting gold back to the Nobel Committee, who minted replacement medals for Franck and von Laue.
Bohr was himself no stranger to Nobel Prizes, as he had won one in 1922. De Hevesy followed suit in 1943. It appears that you could not swing a dead cat in Bohr's lab without hitting a Nobel Prize winner, and it is not surprising that they were smart enough to know about the properties of aqua regia.
To see a video (preceded by a short commercial) of aqua regia in action dissolving a gold coin, click here.
Science! I didn't know you could dissolve gold.
ReplyDeleteAll you need is just a little hydrochloric acid and nitric acid mixed together.
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