A woman visits the mirror installation “Mar de Espelhos” (Sea of Mirrors) ahead of its opening in Rio de Janeiro, Brazil on June 13, 2023. (Photo by Ricardo Moraes/Reuters)

A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)

A citizen wearing protective suit shops at a market in Santiago, Chile, April 16, 2020 Chile has taken stringent measures to contain the virus, including imposing a night time curfew, suspending classes, closing non-essential businesses, and mandating the use of face masks on all public transit. (Photo by Jorge Villegas/Xinhua News Agency)

Early morning storms over the Masai Mara National Reserve, Kenya on August 26, 2016. (Photo by Action Press/Rex Features/Shutterstock)

Zhu Jianqiang, or “strong-willed pig”, famous for surviving more than a month buried in the ruins after the magnitude-8.0 Wenchuan earthquake in 2008, feeds on food sent by admirers wishing it a safe winter in Jianchuan Museum, Chengdu city, southwest China's Sichuan province, 11 January 2021. (Photo by Rex Features/Shutterstock)

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)

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 suspected Vietcong is kicked by a Vietnamese soldier holding a rifle as another soldier attempts to tie his hands on October 22, 1965. The prisoner was one of 15 captured October 21 near Xom Chua when government troops raided in the plain of reeds area. Troops killed 43 suspected Vietcong and seized some arms. (Photo by Richard Merron/AP Photo)