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.

Queen of drums, Sabrina Sato of Unidos de Vila Isabel samba school during the Champions Parade on the last day of Rio de Janeiro 2022 Carnival at Marques de Sapucai Sambadrome on May 01, 2022 in Rio de Janeiro, Brazil. Rio de Janeiro's iconic carnival returns to the sambodrome after a two year suspension and postponements due to the coronavirus pandemic. (Photo by Wagner Meier/Getty Images)

A burning flame and a broad expanse of water are among the few things which do not tire us with their beauty. However, while we have many sources of water around us, it is quite hard to marvel at a burning flame on a daily basis. Melissa Crisp is one of the few people who were able to subdue the element of fire. She is the person who is behind the design of the uniquely-shaped fire pits, which feature mystifying themes, including a pair of lovers, a fire on the rodeo arena, a forest fire, a fiery flower, and a number of others. Each of the fire pits entrances you, and it almost seems like the characters are alive, as the hot fire burns deep within the spheres, casting dancing shadows all around. (Photo by Melissa Crisp)

Revellers are sprayed by a water cannon during a street party called “Bloco Das Barbas” in Rio de Janeiro, Brazil on February 18, 2023. Hundreds of street parties traditionally take place every year in the city before and during Rio de Janeiro's carnival. (Photo by Carl de Souza/AFP Photo)

Reflection in a mirror of a general view of the peloton competing prior to the 112th Tour de France 2025, Stage 10 a 165.3km stage from Ennezat to Le Mont-Dore Puy de Sancy (Super Sancy) 1318m / #UCIWT / on July 14, 2025 in Ennezat, France. (Photo by Tim de Waele/Getty Images)

A woman dances during a rehearsal by the group “Tambores de Olokun” in Rio de Janeiro, Brazil, Sunday, April 17, 2022. The Brazilian municipalities of Rio de Janeiro and Sao Paulo postponed the traditional parades of the carnival samba schools to April 22 - 23, as a result of the COVID-19 pandemic. (Photo by Bruna Prado/AP Photo)

A member of Viradouro samba school performs during the first night of Rio's Carnival parade at the Sambadrome Marques de Sapucai in Rio de Janeiro, Brazil on April 22, 2022. (Photo by Carl de Souza/AFP Photo)

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)