1) Emit flashes 
to flash like lightning
• (v. i.) To flash as lightning.
(ful´gu-rāt) to come and go like a flash of lightning. to destroy by contact with electric sparks generated by a high-frequency current.
Ful'gu·rate intransitive verb [ Latin fulguratus , past participle of fulgurare to flash, from fulgur lightning, from fulgere to shine. See Fulgent .] To flash as lightning. [ R.]
fulgurate, fulgurated, fulgurating 1. To emit (light) in flashes; to flash like lightning. 2. In medicine, to destroy (abnormal tissue, for example) by electric current. 3. To destroy (tissue) with a sparking electrode. 4. To flash or dart like lightning.
A glass-like structure that forms around the element of a current limiting fuse when it operates. It is causes when the heat of the arc melts the silica sand surrounding it.