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.

Отава Ё – Яблочко (Otava Yo – Yablochko; Russian: Яблочко, “Little Apple”). Yablochko is a Russian folk song of chastushka style and dance, traditionally presented as sailors' dance. The choreographed version of the dance first appeared in the 1926 Reinhold Glière ballet The Red Poppy and from there is known in the West as the Russian Sailors Dance.

Volunteers of a Wild Nature Preservation center release a group of owl chicks from the Toro Mountain in Menorca, Balearic Islands, Spain, 31 July 2019. (Photo by David Arquimbau Sintes/EPA/EFE/Rex Features/Shutterstock)

A baby Black-crowned Night Heron squawks in its incubator while being cared for at City Wildlife rescue and rehabilitation center in Washington, DC on May 31, 2017. The heron is one of several that have been brought to CW by the staff at The National Zoo over the past few years. (Photo Linda Davidson/The Washington Post)

A fan of Colombia cheers prior to a qualifying soccer match between for the FIFA World Cup Qatar 2022 Colombia and Chile in Barranquilla, Colombia, Friday, September 10, 2021. (Photo by Fernando Vergara/AP Photo)

A baby orangutan called Barney shows off his dancing at Ragunan Zoo in Jakarta, Indonesia in the first decade of November 2023. (Photo by Syahrul Ramadan/Media Drum Images)

Mott Sreymom, 34, a rat handler with the humanitarian demining organization APOPO, carries an African giant pouched rat back from a landmine field in Siem Reap, Cambodia, Tuesday, June 10, 2025. (Photo by Anton L. Delgado/AP Photo)

A Pelican attempts to take a persons belongings while they are sat in St James' Park, London on Monday, August 11, 2025. Temperatures will soar above 30°C in parts of the UK in the coming days, with another heatwave possible in some areas. (Photo by Yui Mok/PA Images via Getty Images)