Radioactivity Demonstration Kit (ca. 1960s to 1980s)
This demonstration kit was produced by Eduquip Inc. for use in schools, probably during the 1960s through the 1980s. Each of the six boxes contains one of the following chemicals: uranium sulfate, uranium nitrate, sodium sulfate, sodium nitrate, thorium nitrate, and sulfur.
By placing the cubes on a sheet of photographic film for a few days, processing the film, and noting which boxes produced an image, a student could determine which chemicals were radioactive and which were not. This analysis could then be confirmed using a Geiger counter.
Kolb, W. Frame, P. Living with Radiation: The First Hundred Years. Syntec Inc.