Our demo technician Andy needs little excuse to head onto the roof of the Ri building and experiment.

To celebrate Halloween he set off a couple of chemical reactions inside two beautifully carved pumpkins: igniting guncotton with an electric fuse and catalysing a decomposition of hydrogen peroxide by potassium iodide (more commonly known as 'elephant's toothpaste').

Happy Halloween!

Watch another spooky demo by Andy on the Headsqueeze channel http://www.youtube.com/watch?v=_mmUlo88Utw

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