Fulguration /(?)/

Ful·gu·ra·tion

Fulguration

n.
  1. The act of lightening. [R.]
  2. 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 blick. (Assaying)
    A phenomenon called, by the old chemists, fulguration.