A soldier walks on the bank of the river in central Pyongyang, North Korea on April 16, 2017. (Photo by Damir Sagolj/Reuters)

Visitors look up at mock-ups of dinosaur skeletons inside the Museum of Natural History in Pyongyang on September 28, 2016. (Photo by Ed Jones/AFP Photo)

Divers perform during an event to celebrate the upcoming Christmas at the aquarium in Seoul, South Korea, Friday, December 1, 2023. Christmas is one of the biggest holidays celebrated in South Korea. (Photo by Lee Jin-man/AP Photo)

People attend the New Year's eve gala of youth and students at Kim Il Sung Square in Pyongyang, North Korea Sunday, December 31, 2023. (Photo by Jon Chol Jin/AP Photo)

North Korean dance during an evening gala as they celebrate the country's 76th founding anniversary at Kim Il Sung Square in Pyongyang, North Korea Sunday, September 8, 2024. (Photo by Jon Chol Jin/AP Photo)

Embers remain among the debris after most of the buildings were burned to the ground in a wildfire at Gounsa Temple in Uiseong on March 26, 2025. At least 18 people have been killed in one of South Korea's worst wildfire outbreaks, with multiple blazes burning and causing “unprecedented damage”, the acting president said. (Photo by Yasuyoshi Chiba/AFP Photo)

Students participate in a commemorative march near the Arch of Triumph in Pyongyang on April 25, 2025, to mark the 93rd anniversary of the Korean People's Revolutionary Army. (Photo by Kim Won Jin/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.