Seen in a long camera exposure, the Caldor Fire burns on Sunday, August 29, 2021, in Eldorado National Forest, Calif. (Photo by Noah Berger/AP Photo)

A traditional high altitude bonfire burns on the occasion of the Swiss National Day on the “Stanserhorn” mountain near Stans, Switzerland, Sunday, August 1, 2021. (Photo by Urs Flueeler/Keystone via AP Photo)

A woman and a girl in a school uniform run past a barricade of burning tires during a demonstration against high prices and fuel shortages, in Port-au-Prince, Haiti on October 21, 2021. (Photo by Ralph Tedy Erol/Reuters)

A Palestinian protester runs past burning tyres amid clashes with Israeli security forces deploying during a raid in the old city of Nablus, in the occupied West Bank, on December 30, 2022. (Photo by Jaafar Ashtiyeh/AFP Photo)

People walk past burning tires during a protest against Haitian Prime Minister Ariel Henry in Port-au-Prince, Haiti, Monday, February 5, 2024. (Photo by Odelyn Joseph/AP Photo)

A woman poses for photographs while Indonesian police officers burn seized various drugs during a press conference at the regional police headquarters in Banda Aceh on June 12, 2025. (Photo by Chaideer Mahyuddin/AFP Photo)

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.

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)