Chance saved the situation. It occurred to someone to see whether the impurity was radioactive. This was very fortunate, for the impurity actually displayed radioactivity. But what element could have caused it?

   The chemists reported the unknown impurity to be uranium oxide. Was this a discovery? Hardly. Uranium salts had rather long since been used for colouring glass. It was one of the first practical uses of uranium. But in the Roman glasses uranium was evidently a chance admixture.

   That put an end to the story for the time being. But some decades later this forgotten fact came to the knowledge of the American archeologist and chemist Kelly.

After extensive investigations, repeated analyses and comparison of various data, Kelly came to the conclusion that the presence of uranium in the ancient Roman glasses was the rule rather than the exception. The Romans knew about uranium minerals and used them for practical purposes, particularly, for colouring glass.

   Perhaps this is where uranium's biography starts?

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