Czech Republic's Stepan Lukes reacts after the puck gets stuck in his helmet grill during the Euro Hockey Tour match between Austria and Czech Republic in Ostrava, Czech Republic on May 1, 2022. (Photo by David W. Cerny/Reuters)

Denmark's Katrine Veje, left, is comforted by Australia's Charlotte Grant, right, after the Women's World Cup round of 16 soccer match between Australia and Denmark at Stadium Australia in Sydney, Australia, Monday, August 7, 2023. (Photo by Rick Rycroft/AP Photo)

Charlotte FC goalkeeper Kristijan Kahlina deflects a shot by Inter Miami forward Leonardo Campana during the second half of an MLS soccer match, Wednesday, October 18, 2023, in Fort Lauderdale, Fla. (Photo by Rebecca Blackwell/AP Photo)

China perform during the mixed team free preliminaries on day seven of the Doha 2024 World Aquatics Championships at Aspire Dome on February 8, 2024 in Doha, Qatar. (Photo by Clodagh Kilcoyne/Reuters)

Tara Davis-Woodhall, of the United States, reacts after an attempt in the women's long jump during the World Athletics Indoor Championships at the Emirates Arena in Glasgow, Scotland, Sunday, March 3, 2024. (Photo by Bernat Armangue/AP Photo)

Newly hired employees for Japan Airlines (JAL) attend an entrance ceremony in a hangar at Haneda Airport on April 03, 2023 in Tokyo, Japan. 2,000 new employees from 37 JAL group companies were welcomed at the event held for the first time in four years following a hiatus due to the coronavirus pandemic. (Photo by Tomohiro Ohsumi/Getty Images)

Two railway workers chat in front of a flower mural inside a subway station visited by foreign reporters during a government organised tour in Pyongyang, North Korea October 9, 2015. (Photo by Damir Sagolj/Reuters)

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.