I had no idea at the time those contained mercury.
Google "ammonium dichromate volcano" to see LOTS of videos -- or "mercury thiocyanate decomposition" (actually (NH4)2Cr2O7 and Hg(SCN)2, FWIW) to see video of snakes alone. Combining them was pure genius!
I was expecting to see video from the Discovery Channel tonight ...
"We've been attacked by the intelligent, educated segment of the culture." -- Pastor Ray Mummert, Dover, PA, during an attempt to introduce creationism -- er, "intelligent design", into the Dover Public Schools.