A protester gestures as he holds a dog before a burning barricade during protests in Harare, Zimbabwe on January 15, 2019. (Photo by Philimon Bulawayo/Reuters)

Fire retardant is dropped on the Fairview Fire burning near Hemet, California, U.S., September 6, 2022. (Photo by David Swanson/Reuters)

An emu runs to escape an approaching wildfire as it burns near Potero, California, U.S. June 20, 2016. (Photo by Mike Blake/Reuters)

A policeman stands by a burning car, set alight during a communist march in the East End of London. (Photo by Topical Press Agency/Getty Images). Circa 1936

Canadian actress Nina Dobrev kicks her leg up at Burning Man in the first decade of September 2022. (Photo by nina/Instagram)

If we were to burn NH4Cr2O7 with HgSCN in the Dark Ages in Europe and show it to anyone, it is us who would be burning next on a fiery cross of Inquisition. And it’s no wonder, since this experiment produces a truly marvelous result. At first, as you ignite the mixture of NH4Cr2O7 and HgSCN, all you can see is that it is slowly burning with a reddish flame. After a while, however, a crater is formed in the middle of the burning pile, and then, suddenly, tentacle-like appendages start sprouting from the burning mixture. And you can almost hear the scream of the mad occultist – “Come forth, Kraken! Come forth!” But of course, this is simply a chemical reaction that is called the "Pharoah's Serpent". It was also often sold in firework stores until people realized that it was toxic.

Bill Moreau watches as the Black Forest fire burns near his house near Black Forest Road Tuesday afternoon, June 11, 2013, near Colorado Springs, Colo. The Black Forest Fire was one of at least three significant wildfires burning in Colorado amid gusty winds and record-breaking hot, dry weather. (Photo by Christian Murdock/AP Photo/The Colorado Springs Gazette)

A hillside erupts in flame as a raging wildfire fire burns in Placerita Canyon in Santa Clarita, Calif., Monday, July 25, 2016. A raging wildfire that forced thousands from their homes on the edge of Los Angeles continued to burn out of control Monday as frustrated fire officials said residents reluctant to heed evacuation orders made conditions more dangerous and destructive for their neighbors. (Photo by Nick Ut/AP Photo)