DJC wrote:
david lang wrote:

I recall mixing potassium permanganate with something to make a paste
that exploded on contact once dry.


Potasium Permangenate in a liitle heap, make holes in middle as if
mixing cement, pour in glycerine, self-igniting volcano?


Yes indeed, but David's sounds more like ammonium iodide. As often
painted on school assembly hall floors before the Final Assembly in my
youth... Perhaps, like me, he did both?
Douglas de Lacey