Remembering the treatment that had been accorded the Knights and soldiers of St. Elmo, the Maltese inhabitants of Senglea took no prisoners. Hence there arose the expression (used in Malta to this day) 'St. Elmo's pay' for any action in which no mercy is given.

I have a suspicion that when first built, Stonehenge may have glowed blue with St. Elmo's fire during certain times of the year