Women take part in the desert trek “Rose Trip Maroc”, on November 1, 2019 in the erg Chebbi near Merzouga. The Rose Trip Maroc is a female-oriented trek where teams of three must travel through the southern Moroccan Sahara desert with a compass, a map and a topographical reporter. (Photo by Jean-Philippe Ksiazek/AFP Photo)

Roman Cervenka #10 of Czechia celebrates with the trophy and gets a beer thrown on him from his teammates during IHF Ice Hockey World Championship gold medal celebrations with fans at Old Town Square on May 27, 2024 in Prague, Czech Republic. (Photo by RvS.Media/Monika Majer/Getty Images)

A runner takes part in the International World's coldest marathon at minus 53 degrees (–63.4 Fahrenheit) near Oymyakon, the republic of Sakha, also known as Yakutia, Russian Far East, Saturday, January 22, 2022. Sixty five runners, including athletes from the United Arab Emirates, United States and Belarus, started the run at extremely low temperature in Oymyakon, Yakutia's Pole of Cold. The international team of men and women ran full distance and half-marathon. (Photo by Ivan Nikiforov/AP Photo)

A soldier reacts after falling off a horse as members of the King's Troop, Royal Horse Artillery, arrive at Green Park for a gun salute celebrating the King's birthday in London on November 14, 2022. King Charles III is celebrating his first birthday as monarch as he turns 74. (Photo by Daniel Leal/AFP Photo)

Canada's Deanna Stellato-Dudek and Maxime Deschamps perform in the gala exhibition during the ISU Grand Prix of Figure Skating Final in Beijing on December 10, 2023. (Photo by Wang Zhao/AFP Photo)

Paolo Guerrero of Brazil's Internacional reacts after missing an opportunity to score during a Copa Libertadores soccer match against Chile's Palestino in Porto Alegre, Brazil, Tuesday, April 9, 2019. (Photo by Diego Vara/Reuters)

Valeria Gonzalez Maidana of Paraguay performs in the final round of the first Budapest Ballet Grand Prix in the National Dance Theatre in Budapest, Hungary on November 23, 2023. The international ballet competition was launched by the Hungarian Dance University, a leading training facility of Hungarian professional dancers, to promote ballet and dance art in Hungary. The competition offers young dancers an opportunity to compete and gain exposure in the international dance scene, and provides scholarships and career opportunities for the most outstanding dancers. The event runs from 21 to 24 November. (Photo by Tamas Vasvari/EPA)

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.