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.

Gabriel of Arsenal celebrates scoring his team's third goal with teammates during the UEFA Champions League 2024/25 League Phase MD5 match between Sporting Clube de Portugal and Arsenal FC at Estadio Jose Alvalade on November 26, 2024 in Lisbon, Portugal. (Photo by Stuart MacFarlane/Arsenal FC via Getty Images)

Artturi Lehkonen #62 of the Colorado Avalanche scores against goalie Jake Allen #34 of the New Jersey Devils in the first period at Ball Arena on February 26, 2025 in Denver, Colorado. (Photo by Matthew Stockman/Getty Images/AFP Photo)

Van cat walks in the snow in Yuzuncu Yil University's “cat villa” where they are carefully cared, in Van, Turkiye on January 21, 2022. One of the most important symbols of Van province of Turkiye endangered Van cats are taken under protection at the Van Cat Research and Application Center of Yuzuncu Yil University. They have been the subject of many scientific studies with their unique characteristics. Efforts are continuing to protect the extinction of the Van cat, which is known for its sensuality, friendliness, white silky fur, lion's walk, fluffy tail, different eye colors and fondness for water. (Photo by Ozkan Bilgin/Anadolu Agency via Getty Images)

Mates Jimi Hunt and Dan Drupstee dug the 650m slippery slide on a property at Helensville, northwest of Auckland and opened it this weekend as part of a festival to help combat depression.

People of the LGBTQI community pose for a photo on a large rainbow colored flag as they take part in the parade to mark Thailand Pride Festival 2022 in Bangkok, Thailand, 27 November 2022. Thailand's LGBTQI groups and foreigners attended the Pride festival to raise awareness and promote sexual diversity and equal rights for the Lesbian, Gay, Bisexual, Transgender and Queer (LGBTQ) community. The festival also aims to promote tourism in Thailand as Covid-19 restrictions are being lifted, with hopes to becomes an annual and sustainable event in November. (Photo by Narong Sangnak/EPA/EFE/Rex Features/Shutterstock)

Photographer and editor with Reuters for 22 years, Andrew Winning has died of brain cancer at the age of 49. Here: Elite special police run for cover after gunfire was heard from inside the Japanese ambassador's residence in Lima, Peru, January 27, 1997. At the moment the shots were fired, police were parading past the residence in a show of force, and helicopters were flying above. Earlier, several armored personnel carriers rolled past the compound. Tupac Amaru rebels had seized the diplomatic compound December 17 and held 72 hostages. (Photo by Andrew Winning/Reuters)

On Set with David Bowie and Tilda Swinton. A photo taken by Director Floria Sigismondi on set of The Stars (Are Out Tonight), featuring Tilda Swinton.