A burning tank is in Daraa, on March 9, 2013. (Photo by Ali Abu-Salah/Reuters/Shaam News Network via The Atlantic)

A brightly burning magnesium-rich meteor known as a bolide was captured near Bude, Cornwall on January 24, 2020. (Photo by Chris Small/Apex News)

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)

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)

Costumed children from the local Shade performance group perform their show during the annual Brixton Burn in Johannesburg, South Africa, 28 August 2021. The annual event is run by members of the “Afrikaburn” community which is a regional event of “Burning Man” in the United States. (Photo by Kim Ludbrook/EPA/EFE)

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.