spinthariscope

thumb|200px|right|A low quality toy spinthariscope taken from a 1950s Chemcraft brand "Atomic energy" chemistry experimentation set thumb|A spinthariscope crafted by Robert Drosten in Belgium in 1905 and used in the University of Mons Faculty of Engineering ("Polytech Mons") at the beginning of the 20th century. A spinthariscope () is a device for observing individual nuclear disintegrations caused by the interaction of ionizing radiation with a phosphor (see radioluminescence) or scintillator.

==Invention== 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 () "spark".