Radium Bread (ca 1920)
Envelopes for radium bread produced by the Hippmann-Blach bakery located in St. Joachimstal (Jachymov, now part of the Czech Republic). Joachimstal is sometimes referred to as the "Cradle of the Atomic Age."
The yellow color is due to the cards I slipped into the envelopes to make the lettering stand out more clearly.
The envelope above left, written in German, indicates that radium water from Joachimstal was used in the production of the bread ("Unter Zusatz von St. Joachimstaler Radiumwasser"). As such, the bread would have contained slightly elevated levels of radium, but nothing that could be considered dangerous. The envelope above right is written in Hungarian.
Translation courtesy of Franz Schönhofer.