Waxahachie firefighters battle a massive fire at the Magnablend chemical processing plant on October 3, 2011 in Waxahachie, Texas. The burning chemical plant is not far from several residential areas and Wedgeworth Elementary School. (Photo by Tom Pennington/Getty Images)

Photographers work on the red carpet after the screening of the film “Mad Max: Fury Road” out of competition at the 68th Cannes Film Festival in Cannes, southern France, May 14, 2015. (Photo by Regis Duvignau/Reuters)

A reveler jumps from a fountain onto the crowd below, after the launch of the “Chupinazo” rocket, to celebrate the official opening of the 2014 San Fermin fiestas in Pamplona, Spain, Sunday, July 6, 2014. Revelers from around the world turned out here to kick off the festival with a messy party in the Pamplona town square, one day before the first of eight days of the running of the bulls glorified by Ernest Hemingway's 1926 novel “The Sun Also Rises”. (Photo by Andres Kudacki/AP Photo)

Russian President Vladimir Putin, right, and North Korea's leader Kim Jong Un pose for photographers during their meeting in Vladivostok, Russia, Thursday, April 25, 2019. Putin and Kim are set to have one-on-one meeting at the Far Eastern State University on the Russky Island across a bridge from Vladivostok. The meeting will be followed by broader talks involving officials from both sides. (Photo by Alexander Zemlianichenko/AP Photo/Pool)

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.

A youth in costume hurries past a mural after dancing at the Sun Festival in Cotacachi, Ecuador, Sunday, June 24, 2018. Across the Andes, from the tip of Argentina as far north as Colombia, indigenous communities are gathering for the southern hemisphere's winter solstice to honor the ancient sun god. (Photo by Dolores Ochoa/AP Photo)

A woman waits at a polio immunisation health centre, in Maiduguri, Borno State, Nigeria, August 29, 2016. Nigeria's military has liberated large swathes of land from Boko Haram but a ride with an army convoy, all guns firing for fear of ambush, shows how far the northeast is from normality after a brutal Islamist insurgency that has displaced millions. (Photo by Afolabi Sotunde/Reuters)

Children react as a carnivorous theropod known as the Australovenator dinosaur walks through crowds along the Southbank, in London, Monday, February 18, 2013. The dinosaur is one of many that can be visited at the Erth's Dinosaur Petting Zoo, visiting from Australia, the creatures can be touched and fed at the Southbank Centre. (Photo by Kirsty Wigglesworth/AP Photo)