Police officers detain a man during a gathering in memory of Russian opposition leader Alexei Navalny near the Wall of Grief monument to the victims of political repressions in Moscow, Russia on February 17, 2024. (Photo by Reuters/Stringer)

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.

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)

Couples dance samba as smoke rises from a burning pyrotechnics warehouse in Moscow on June 19 2021. (Photo by Dimitar Dilkoff/AFP Photo)

People push a stretcher carrying an injured victim after a mosque blast inside the police headquarters, at a hospital in Peshawar on January 30, 2023. A blast at a mosque inside a police headquarters in Pakistan on January 30 killed at least 25 worshippers and wounded 120 more, officials said. (Photo by Zafar Iqbal/AFP Photo)

Metropolitan Police run as they escort people, some without shoes, away from a shooting scene in the northwest part of the city on April 22, 2022 in Washington, DC. Police evacuated residents from the shooting scene Friday afternoon and there were reports of several shooting victims. (Photo by Kevin Dietsch/Getty Images)