The spinthariscope was invented by William Crookes in 1903. While observing the apparently uniform fluorescence on a zinc sulfide screen created by the radioactive emissions (mostly alpha radiation) of a sample of radium bromide, he spilled some of the sample, and, owing to its extreme rarity and cost, he was eager to find and recover it. Upon inspecting the zinc sulfide screen under a microscope, he noticed separate flashes of light created by individual alpha particle collisions with the screen. Crookes took his discovery a step further and invented a device specifically intended to view these scintillations. It consisted of a small screen coated with zinc sulfide affixed to the end of a tube, with a tiny amount of radium salt suspended a short distance from the screen and a lens on the other end of the tube for viewing the screen. Crookes named his device from Greek σπινθήρ spinth´ēr "spark."
 Toy spinthariscopes
Spinthariscopes were quickly replaced with more accurate and quantitative devices for measuring radiation in scientific experiments, but enjoyed a modest revival in the mid 20th century as children's educational toys. They can still be bought today as instructional novelties, but they now use americium or thorium.
- Crookes, W. Certain Properties of the Emanations of Radium. Chemical News; Vol. 87:241; 1903.
- Frame, Paul W. "The Crookes Spinthariscope". Oak Ridge Associated Universities. Retrieved 2 May 2013.
- Alfred Romer (1960). The Restless Atom: The Awakening of Nuclear Physics. Anchor Books. Retrieved 2 May 2013.
- Bonnier Corporation (June 2007). Popular Science. Bonnier Corporation. pp. 86–. ISSN 01617370. Retrieved 2 May 2013.
- Modern spinthariscope
- Elements of electricity: a practical discussion of the fundamental laws and ... by Robert Andrews Millikan, Edwin Sherwood Bishop, American Technical Society