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.

Ford displays the drive train of the F150 Raptor SVT truck during the media preview of the Chicago Auto Show at McCormick Place on February 8, 2012 in Chicago, Illinois. The show, which is the largest and oldest auto show in the country, opens to the public on February 10. (Photo by Scott Olson/Getty Images)

A young protester takes part in a protest near Tahrir Square to call for the fall of Islamist President on January 24, 2012 in Cairo. (Photo by Mohammed Abed/AFP Photo via The Atlantic)

“Unexpected x2 (a.k.a. “how much is that doggie in the window”)”. Taiwan, 2011. (Photo and caption by Asian (Street) Impressions)

Reuters photographer Carlos Barria recently spent time in Shanghai, China, the fastest-growing city in the world. A week ago, he took this amazing shot, recreating the same framing and perspective as a photograph taken in 1987, showing what a difference 26 years can make. (Photo by Carlos Barria/Reuters/Stringer via The Atlantic)

Maharashtrian women dressed in traditional costumes attend celebrations to mark the Gudi Padwa festival in Mumbai March 21, 2015. The festival marks the beginning of the new year for Maharashtrians and is celebrated widely in Maharashtra and in the Konkan region. (Photo by Danish Siddiqui/Reuters)