Demonstrators dance around a burning an effigy of the Russian President Vladimir Putin during an anti-war action in Tbilisi, Georgia, Sunday, March 27, 2022. (Photo by AP Photo/Stringer)

A burning tree is seen during a fire in an area of the Amazon rainforest in Itapua do Oeste, Rondonia State, Brazil, September 11, 2019. (Photo by Bruno Kelly/Reuters)

A man takes a selfie next to a burning barricade during a protest against the government in the streets of Port-au-Prince, Haiti, February 10, 2019. (Photo by Jeanty Junior Augustin/Reuters)

Light painting on the beach at Walton-on-the-Naze in Essex, United Kingdom on April 25, 2023 using burning steel wool spun around on a rope sending sparks flying. (Photo by Kevin Jay/Picture Exclusive)

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 leopard skin burns as Indian officials and activists burn wildlife contraband including tiger and leopard skins, and bones as part of a campaign to save the tiger in Mumbai, India, Tuesday, July 30, 2013. Despite conservation efforts, tiger numbers in India have declined due to rampant poaching of the cats for their valuable pelts and body parts that are highly prized in traditional Chinese medicine. (Photo by Rafiq Maqbool/AP Photo)

Residents look on as flames burn through bush on January 04, 2020 in Lake Tabourie, Australia. A state of emergency has been declared across NSW with dangerous fire conditions forecast for Saturday, as more than 140 bushfires continue to burn. There have been eight confirmed deaths in NSW since Monday 30 December. 1365 homes have been lost, while 3.6 million hectares have been burnt this fire season. (Photo by Brett Hemmings/Getty Images)

A police officer holds a pistol during clashes with protesters near a burning tyre barricade in the Kariobangi slum of Nairobi, Kenya Friday, May 8, 2020. Hundreds of protesters blocked one of the capital's major highways with burning tires to protest government demolitions of the homes of more than 7,000 people and the closure of a major food market, causing many to sleep out in the rain and cold because of restrictions on movement due to the coronavirus. (Photo by Brian Inganga/AP Photo)