The most unholiest chemical reaction you`ll ever see

Remember those little black tablets you would light during the 4th of July, Canada Day or any other holiday celebration where fireworks were there a plenty?
Well in this video the chemical you see being spread across the bottom of the tank is Hg(SCN)2, or Mercury(II) Thiocyanate, its pretty much the same thing ( I remember them being called snakes) So you know these products are banned now, probably a good thing considering mercury vapours are pretty dangerous.