TheConversationUS, 
In 1911, George de Hevesy had the sneaking suspicion that the kitchen of his boarding house cafeteria was reusing leftovers in their soup.
So he came up with a plan and sneakily sprinkled a small amount of radioactive material in his leftover meat. A few days later, he measured the radioactivity in the prepared food – catching his landlady red-handed. It was the first successful radioactive tracer experiment.
https://theconversation.com/how-a-disgruntled-scientist-looking-to-prove-his-food-wasnt-fresh-discovered-radioactive-tracers-and-won-a-nobel-prize-80-years-ago-214784
@histodons #histodonds #historyofscience
