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.

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/AP Photo)

Mount Sinabung volcano erupts, as seen from Tiga Pancur village, Karo Regency in Indonesia's North Sumatra province, in this October 8, 2014 file photo. (Photo by Y. T. Haryono/Reuters)

A woman wearing a sweet girl cosplay mask strikes a pose during a flower watching or Hanami event, in the Japanese Garden of Bucharest, Romania, April 13, 2024. (Photo by Andreea Alexandru/AP Photo)

People gather for the second annual “Cat Beauty Festival” organized by Royal Veterinary Hospital in Sulaymaniyah, Iraq on July 2, 2025. Around 200 cats participated in the event, where the first round was determined by social media votes. The winner, a cat named “Gule Rana”, was selected by a jury. The festival aims to promote animal love and raise awareness about feline care. (Photo by Fariq Faraj Mahmood/Anadolu via Getty Images)

Mexican clown Gabriela Munoz, whose clown name is Chula the Clown, looks at herself in the mirror after putting on her make up during an interview in Mexico City, Friday, August 26, 2022. (Photo by Berenice Bautista/AP Photo)

A festival goer spins a light strip as she dances to electronic music in front of the Belleville stage during the 45th edition of the Paleo Festival, in Nyon, Switzerland, 24 July 2022. The Paleo is the largest open-air music festival in the western part of Switzerland. (Photo by Valentin Flauraud/EPA/EFE)