A participant marches during the Tokyo Rainbow Pride parade, celebrating advances in LGBTQ+ rights and calling for marriage equality, in Tokyo, Japan on April 21, 2024. (Photo by Issei Kato/Reuters)

Revelers jump on a rainbow painted crosswalk in Church Street, Toronto's LGBT neighbourhood, before “WorldPride”, a gay pride parade, in Toronto, June 29, 2014. Toronto is hosting WorldPride, a week-long event that celebrates the lesbian, gay, bisexual and transgender (LGBT) community. (Photo by Mark Blinch/Reuters)

Walkers marvel at a fog bow over Curbar Edge, Derbyshire in the last decade of October 2023. The phenomenon is similar to a rainbow, but because the water droplets that cause fog are so small, its colours are very weak. (Photo by Richard Bowring/Animal News Agency)

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)

Bangladeshi children from Khan Tea garden posing for photos on March 23, 2022 with their faces painted after adorning with colors like Rainbows on the celebration of the annual Hindu festival of colors, known as Holi festival marking the onset of spring. (Photo by Md Rafayat Haque Khan/Eyepix Group/Rex Features/Shutterstock)

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)