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.

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)

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)

Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)

People watch waves crash over the sea wall in Revere, Massachusetts on January 13, 2024. The Massachusetts Emergency Management Agency is reminding residents of the possibility of flooding in low-lying areas and streets as a third storm in a week batters the state. (Photo by Joseph Prezioso/AFP Photo)

Manchester City's Belgian midfielder #11 Jeremy Doku eyes the ball during the UEFA Champions League quarter-final second-leg football match between Manchester City and Real Madrid, at the Etihad Stadium, in Manchester, north-west England, on April 17, 2024. (Photo by Paul Ellis/AFP Photo)

One woman was pictured sitting bare foot on a pavement in Leeds in the northern English county of Yorkshire on May 30, 2021. With the sun streaming down, Brits have been taking full advantage of the three-day weekend by packing out pub gardens and lining up the beers at bars. (Photo by Nb press ltd)

A woman reacts during the annual tomato fight fiesta called “Tomatina”, tomato fight fiesta, in the village of Bunol near Valencia, Spain, Wednesday, August 30, 2023. Thousands gather in this eastern Spanish town for the annual street tomato battle that leaves the streets and participants drenched in red pulp from 120,000 kilos of tomatoes. (Photo by Alberto Saiz/AP Photo)