"Back on the subject of mercury, and of cyanate salts in general, did you know that mercuric thiocyanate was the chemical used to make Pharoah's Serpents (snakes) for a long time?  Picture all these kiddies, and all these parents who didn't want their kids messing with "dangerous" fireworks, all gathered around a couple hundred grams of burning mercury compounds." 

    - found this while reading about mercury fulminate on the internot.