“Users should not take ore samples out of their jars, for they tend to flake and crumble and you would run the risk of having radioactive ore spread out in your laboratory.” Such was the warning that came with the Gilbert U-238 Atomic Energy Lab, a 1950s science kit that included four small jars of actual uranium. Budding young nuclear scientists were encouraged to use the enclosed instruments to measure the samples’ radioactivity, observe radioactive decay, and even go prospecting for radioactive ores. Yes, the Gilbert company definitely intended for kids to try this at home. And so the company’s warning was couched not in terms of health risk but rather as bad scientific practice: Removing the ore from its jar would raise the background radiation, thereby invalidating your experimental results.

When the Atomic Energy Lab hit the market in 1950, it was one of the most elaborate science kits available. In addition to uranium, it had beta-alpha, beta, and gamma radiation sources. It contained a cloud chamber, a spinthariscope (a simple device for watching atoms decay), an electroscope, and a Geiger counter, as well as a 60-page instruction book and a guide to mining uranium.

Also included in every kit was Learn How Dagwood Splits the Atom! Part comic book, part educational manual, it used the popular comic strip characters Blondie and Dagwood Bumstead, as well as their children, dog, and friends, to explain the basics of atomic energy. In the tale, they all shrink to the size of atoms while Mandrake the Magician, another popular comic strip hero of the day, supervises the experiment and explains how to split an atom of uranium-235.

Despite the incongruity of a magician explaining science, the booklet was prepared with expert advice. Published in 1949 by King Features Syndicate, it featured Leslie R. Groves (director of the Manhattan Project) and John R. Dunning (a physicist who verified fission of the uranium atom) as consultants.

Groves’s opening statement encourages the pursuit of truth, facts, and knowledge. He strives to allay readers’ fears about atomic energy and encourages them to see how it can be used for peacetime pursuits. The journalist Bob Considine, who covered the atomic bomb tests at Bikini, likewise dwells on the positive possibilities of nuclear energy and the availability of careers in the field.

Alas, fewer than 5,000 of the Gilbert kits were sold, and it remained on the market only until 1951. The lackluster sales may have been due to the eye-popping price: US $49.50, or about $500 today. Two competing sets, from the Porter Chemical Company, also contained uranium ore and were advertised as having atomic energy components, but retailed for $10 and $25.