Fŭl’gu-rā’tiōn, n.

n. [Lat. fulguratio, Fr. fulguration.]

1. The act of lightening. [Obs.] Donne.
2. (Assaying.) The sudden brightening of a fused globule of gold or silver, when the last film of the oxide of lead or copper leaves its surface.

A phenomenon called, by the old chemists, fulguration. Ure.