In this photograph taken on April 28, 2018, Afghan children work at a coal yard on the outskirts of Jalalabad, Afghanistan. (Photo by Noorullah Shirzada/AFP Photo)

Nursing students attend a capping ceremony on May 10, 2021 in Jinan, Shandong Province of China. International Nurses Day is observed annually on May 12. (Photo by Zhang Yong/China News Service via Getty Images)

This aerial picture taken on August 16, 2020, shows the MV Wakashio bulk carrier that had run aground and broke into two parts near Blue Bay Marine Park, Mauritius. A ship that has leaked more than 1,000 tonnes of oil in pristine waters off the Mauritius coast has split into two, its Japanese operator said August 16, 2020. (Photo by AFP Photo/Stringer)

Meital Ben Ari, a co-founder of “Freedom Farm” pats Gary, a sheep with leg braces, at the farm which serves as a refuge for mostly disabled animals in Moshav Olesh, Israel on March 7, 2019. (Photo by Nir Elias/Reuters)

A rooster is seen with the Zigana Mountain Pass, an important road route connecting the Eastern Black Sea region to Eastern Anatolia at an altitude of 2,050 meters, and the surrounding high areas after effective snowfall has occurred intermittently on October 23, 2024 in Trabzon, Turkiye. (Photo by Hakan Burak Altunoz/Anadolu via Getty Images)

Iraqi rapid response forces take a selfie picture outside a hospital damaged by clashes during a battle between Iraqi forces and Islamic State militants in the Wahda district of eastern Mosul, Iraq, January 8, 2017. (Photo by Alaa Al-Marjani/Reuters)

Spectators in colourful attire cheer as the pack of riders (peloton) cycles by during the 14th stage of the 111th edition of the Tour de France cycling race, 151,9 km between Pau and Saint-Lary-Soulan Pla d'Adet, in the Pyrenees mountains in southwestern France, on July 13, 2024. (Photo by Anne-Christine Poujoulat/AFP Photo)

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.