Revellers kiss under a rainbow flag during the Gay Pride parade along Paulista Avenue in Sao Paulo, Brazil on June 3, 2018. (Photo by Nacho Doce/Reuters)

A boy with his bike is seen as rainbow appears after a rainfall in Edremit district of Van province in Turkey on July 08, 2020. (Photo by Ozkan Bilgin/Anadolu Agency via Getty Images)

A model presents a creation from the LaQuan Smith Fall and Winter '23 collection at the Rainbow Room during Fashion Week in New York City, New York, U.S., February 13, 2023. (Photo by Caitlin Ochs/Reuters)

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.

An Indian Hindu devotee pours milk on a snake as an offering during the annual Nag Panchami festival, dedicated to the worship of snakes outside the Nagvasuki temple, in Allahabad, on July 28, 2017. Officially the snake charmers' profession is banned in India, but many in the country offered prayers and milk blessings to cobras and other deadly serpents on July 28 in an annual tribute. The 800,000 charmers and their young apprentices come to the fore for the Nag Panchami festival which dates back several centuries. (Photo by Sanjay Kanojia/AFP Photo)

A woman walks up a stairway painted in the rainbow colors in Bucharest, Romania, Saturday, July 11, 2020. Romania reported 698 new COVID-19 infections in the last 24 hours, the highest level since the pandemic reached the country in February. (Photo by Vadim Ghirda/AP Photo)

Members of the Apollo Rainbow Dancers stretch out in special A train late on May 4, 1985, in New York. The legendary Apollo Theatre celebrated its 50th anniversary in an official reopening after a 15 month refurbishing with a celebrity studded evening. (Photo by Ray Stubblebine/AP Photo)

A woman walks up a stairway painted in the rainbow colors in Bucharest, Romania, Saturday, July 11, 2020. Romania reported 698 new COVID-19 infections in the last 24 hours, the highest level since the pandemic reached the country in February. (Photo by Vadim Ghirda/AP Photo)