Italy's Alexandra Oberstolz and Katharina Sofie Kofler compete in the women's-doubles luge event at the Gangwon 2024 Winter Youth Olympic Games in the Alpensia Sliding Centre in Gangwon, South Korea, on January 21, 2024. (Photo by OIS/IOC/Handout via Reuters)

Harry Potter fan Emil Valkov, 7, from Bulgaria, who travelled to Britain with his family to attend the event for his older sister's birthday, poses for a photo at “Platform 9 3/4” during Back to Hogwarts Day at Kings Cross Station in London, Britain on September 1, 2023. (Photo by Hollie Adams/Reuters)

(L-R) Dustin Poirier punches Conor McGregor of Ireland in a lightweight fight during the UFC 257 event inside Etihad Arena on UFC Fight Island on January 23, 2021 in Abu Dhabi, United Arab Emirates. (Photo by Jeff Bottari/Zuffa LLC)

Visitors pass an exhibit for Sculpture by the Sea, along the coastal walk from Bondi to Tamarama in Sydney, Australia on October 24, 2025. The annual event is Australia’s largest annual outdoor sculpture exhibition. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Jackie Galarza greets the Camarasaurus dinosaur held by Houston Ferguson during the “Jurassic Quest” experience at Broward County Convention Center on July 08, 2022 in Fort Lauderdale, Florida. Fans of dinosaurs can walk through moving and roaring animatronic replicas of the now extinct creatures during the three-day event. (Photo by Joe Raedle/Getty Images)

Lee Kiefer of the USA (L) and Inna Deriglazova of Russia (R) in action during the women's Foil Individual Gold Medal Bout of the Fencing events of the Tokyo 2020 Olympic Games at the Makuhari Messe convention centre in Chiba, Japan, 25 July 2021. (Photo by Kiyoshi Ota/EPA/EFE)

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 general view of the Vintage and Rare Guitars shop on Denmark Street on April 20, 2011 in London, England. Denmark Street, in the Soho area of central London, traces its musical connections back to the 1890s and is famous for its connection to contemporary British music after recording studios started setting up there in the 1960s. Many world-renowned recording artists, including: Jimi Hendrix, The s*x Pistols and Elton John have played and recorded in the street. The Rolling Stones recorded their first album in 1964 at the street's Regent Sounds Studio's. Known as London's 'Tin Pan Alley' Denmark Street is regarded as one of, if not the, best music streets in Europe and contains numerous specialist music shops, with many boasting of a long and prestigious musical history.