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 handout photo made available by TeideLab shows an image composed of 200 pictures that shows the lightning activity between 3 am and 7am during a storm in Izana, Tenerife, Canary Islands, Spain, 27 October 2019. Over 2,000 lighting strikes fell mostly over Tenerife island last 26 October during a strong storm. (Photo by Daniel López/EPA/EFE/TeideLab)

Kanye West and Bianca Censori were spotted in Prato, Italy on June 1, 2024, where the rapper oversees his clothing production. Bianca holds sketches of designs, hinting at the creative process behind their venture. (Photo by Focus Tuscany/Backgrid USA)

People in traditional dance before competing in the 53rd Verdiales music contest in Malaga, southern Spain December 28, 2014. Verdiales is a form of traditional Flamenco music, which is common in the province of Malaga. Members of singing groups, known as “pandas”, wear traditional costumes decked with flowers and other accessories as they perform in the contest, which is held annually on December 28. (Photo by Jon Nazca/Reuters)

A man watches a classic Turkish movie from his car at a temporary drive-in theatre held in a shopping mall car park amid the ongoing Covid-19 pandemic on May 28, 2020 in Istanbul, Turkey. Istanbul and other major cities across Turkey have begun to ease restrictions and have started preparations for the reopening of some locations, shops and services as infection rates continue to drop. As of May 28, Turkey has reported 4,461 coronavirus-related deaths and 160,979 confirmed cases. (Photo by Chris McGrath/Getty Images)

An officer is on fire as demonstrators clash with police during a protest against plans for new austerity measures on June 28, 2011 in Athens, Greece. Greece's largest labor unions have called for a 48-hour strike, while the Socialist government is beginning to push through legislation for cost cutting reforms. (Photo by Milos Bicanski/Getty Images)

A woman washes her dishes outside the temporary shelter built near the houses damaged during an earthquake earlier this year, in Bhaktapur, Nepal December 28, 2015. (Photo by Navesh Chitrakar/Reuters)