A racegoer arrives for Ladies Day of the Royal Ascot horse racing meeting, at Ascot Racecourse in Ascot, England, Thursday, June 22, 2023. (Photo by Alastair Grant/AP Photo)

Colombia's Egan Bernal pedals as he warms up ahead of the 10th stage of the Giro d'Italia cycling race, an individual time trial from Lucca to Pisa, Italy, Tuesday, May 20, 2025. (Photo by Marco Alpozzi/LaPresse via AP Photo)

Event entertainer Holly Egan poses with a guitar using an angle grinder as Kevin Jay and Nigel Cox spin burning steel wool, sending sparks flying under the A13 in Essex, UK on April 4, 2024. (Photo by Kevin Jay/Picture Exclusive)

From the “Paradise Revisited” story in the November 2013 issue of National Geographic magazine, this image is a beautiful vision of father and son fishermen as they move through the multicolored coral gardens of Kembe Bay, Papua New Guinea, in a traditional outrigger canoe. (Photo by David Doubilet/National Geographic Creative)

Afghan female police cadets are seen during their graduation ceremony at Sivas Police Vocational Center Directorate in Sivas, Turkey on March 13, 2018. (Photo by Serhat Zafer/Anadolu Agency/Getty Images)

Residents of Mathare slum fill bags with coal in hard conditions in the capital of Kenya, Nairobi on November 06, 2023. The coal that workers produce with primitive methods by working overtime in unlicensed workshops is used for heating, cooking and other daily needs. (Photo by Gerald Anderson/Anadolu via Getty Images)

Spain's Lucia Corrales, left and Canada's Florianne Jourde fight for the ball during a U-20 Women's World Cup round of sixteen soccer match in Cali, Colombia, Wednesday, September 11, 2024. (Photo by Dolores Ochoa/AP 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.