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.

The annual Antarctic photography exhibition, which is part of Hobart’s Antarctica festival is back on with its chilly, majestic imagery. The winner this year is Sydney’s Sam Edmonds with his striking photo of a gentoo penguin in the snow. Here: Casey Station 2017. (Photo by Chris J. Wilson/The Guardian)

A girl washes the body paint off her arm on the shore of Lake Balaton during the coinciding Strand Festival and B.My.Lake Festival in Zamardi, 110 kms southwest of Budapest, Hungary, 24 August 2016. (Photo by Zoltan Balogh/EPA)

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)

Chinese-American actress Bai Ling is seen on October 15, 2018 in Los Angeles, CA. (Photo by Hollywood To You/Star Max/GC Images)

Ed Sheeran, Taylor Swift and Selena Gomez attend The 58th GRAMMY Awards at Staples Center on February 15, 2016 in Los Angeles, California. (Photo by Kevin Mazur/WireImage)

Early morning paddle boarder enjoys late days of summer on Trent Severn Waterway in Rosedale, Ont., Thursday, September 3, 2020. (Photo by Canadian Press/Rex Features/Shutterstock)