Spinthariscopic

Spinthariscope Spin*thar"i*scope, n. [Gr. spinqari`s spark + -scope.] A small instrument containing a minute particle of a radium compound mounted in front of a fluorescent screen and viewed with magnifying lenses. The tiny flashes produced by the continual bombardment of the screen by the [alpha] rays are thus rendered visible. -- {Spin*thar`i*scop"ic}, a. [Webster 1913 Suppl.]