Ful"gu*ra`tion (?), n. [L.
fulguratio: cf. F. fulguration.] 1.
The act of lightening. [R.] 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; -- also called
A phenomenon called, by the old chemists,