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.

White horses of the Camargue thunder through the shallow salt flats at sunset on December 8, 2022. Known as Horses of the Sea, the breed native to the wetlands in southern France is one of the oldest in the world. (Photo by Nathalie Mountain/Media Drum Images)

A police officer tries to prevent an anti-government protester from pulling the hair of a woman who is part of group that appeared to show their support for the government during a march of healthcare workers critical of the government, in La Paz, Bolivia, on July 21, 2022. (Photo by Juan Karita/AP Photo)

Local resident Rita holds a cat while her neighbour Raisa saws firewood next to their residential building heavily damaged by permanent Russian military strikes in the front line town of Avdiivka, amid Russia's attack on Ukraine, in Donetsk region, Ukraine on November 8, 2023. (Photo by Serhii Nuzhnenko/Radio Free Europe/Radio Liberty via Reuters)

A woman is soaked as she runs down the street as revellers take part in a water fight on Khao San road on the eve of Thai New Year, locally known as Songkran, in Bangkok on April 12, 2023. (Photo by Jack Taylor/AFP Photo)

People struggle to hold onto their umbrellas in a crosswalk in the rain in Seoul, South Korea, 08 August 2022, as the rainy seas​on revisits the country. (Photo by Yonhap/EPA/EFE)

People splash each other in downtown Yerevan, Armenia during an annual Vardavar holiday on July 16, 2023. Vardavar is a traditional Armenian water festival, with people drenching each other, dating back to pagan times. The ancient festival is traditionally associated with the goddess Astghik, who was the goddess of water, beauty, love, and fertility. (Photo by Karen Minasyan/AFP Photo)