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.

Riot police help an injured anti-government protester after scuffles broke out with women police officers on a road leading to the parliament building, during a protest in Beirut on November 19, 2019. Thousands of protesters rallying against the Lebanese political elite blocked roads in central Beirut on Tuesday, preventing lawmakers from reaching the parliament and forcing the postponement of a legislative session. (Photo by Bilal Hussein/AP Photo)

An Asian elephant called “Plai Deaw” goes for a walk on a mountain road in Nakhon Nayok, Thailand on July 11, 2022. The bull has become well known in the area for his taste for venturing out from the deep forest and emerging among cars and village homes. Thailand has an estimated 2,000 Asian elephants living in the wild but there is often conflict when they come into contact with humans on roads and in villages. A similar number of elephants are kept captive where they work in zoos and are hired out for religious festivals and weddings. (Photo by Mongkol Pitakmoo/ViralPress)

A man carrying vegetables is stopped by police at a barricade on a road during a 21-day nationwide lockdown to limit the spreading of coronavirus disease (COVID-19) in Chennai, India, March 25, 2020. (Photo by P. Ravikumar/Reuters)

A herd of wild monkeys ask for food from passing vehicles along a mountain road after a snowfall on October 20, 2020 in Luhuo County, Sichuan Province of China. (Photo by Jin Shujie/VCG via Getty Images)

A goose walks on the road as Belarusian villagers take part in the Yurya religious rite to bring a good harvest in the village of Lutki, some 270 km south of Minsk, on May 6, 2019. (Photo by Sergei Gapon/AFP Photo)

A man walks past a stranded public transport bus on a road flooded by heavy rains in Mumbai, India, August 5, 2016. (Photo by Shailesh Andrade/Reuters)

A boy makes his way on a bicycle along a flooded road near the Ganges River in Allahabad on August 23, 2022, as water levels rose following monsoon rainfalls. (Photo by Sanjay Kanojia/AFP Photo)