Glow in the dark
Distributed through Kix cereal for 15 cents and a box top, the ring was more than a novelty. Hidden inside was a tiny scientific instrument called a spinthariscope containing a minute amount of radioactive polonium-210.
After entering a dark room and allowing their eyes to adjust, children could look through a small lens and watch tiny flashes appear as alpha particles struck a zinc sulfide screen.
Advertisements presented the effect as a chance to witness atomic energy in action and assured families that the radioactive material inside the ring was harmless and the toy was “perfectly safe.”
The ring reflected the enormous fascination with nuclear science that followed World War II, when atomic energy was marketed not only as powerful technology but as something exciting, futuristic, and educational.
Today, the idea of deliberately putting radioactive material inside a children’s cereal prize seems almost impossible to imagine.
In 1947, it was sold as science you could wear on your finger.
