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.

David Pena poses for a photograph with his Lada 2101 built in 1979 on a street in Havana February 9, 2015. Getting parts from the United States is cheaper than in Cuba, where state-run stores sell them at four times the cost, said Pena, a mechanic and president of the Russian Car Club in Havana who drives a souped-up, sporty red 1972 Lada 2101 that he fixed himself. His own Lada has a Fiat engine and an extra Alfa Romeo carburetor. (Photo by Enrique De La Osa/Reuters)

The second and final qualification motor (QM-2) test for the Space Launch System's booster, June 28, 2016, at Orbital ATK Propulsion Systems test facilities in Promontory, Utah. During the Space Launch System flight the boosters will provide more than 75 percent of the thrust needed to escape the gravitational pull of the Earth, the first step on NASA's Journey to Mars. (Photo by Bill Ingalls/NASA)

An adult periodical cicada, in the process of shedding its nymphal skin, is visible on Saturday, May 11, 2024, in Cincinnati. There are two large compound eyes, which are used to visually perceive the world around them, and three small, jewel-like, simple eyes called ocelli at center. (Photo by Carolyn Kaster/AP Photo)

A woman walks inside a building in downtown Havana, Cuba April 21, 2016. (Photo by Alexandre Meneghini/Reuters)

These photos and video were taken in the Russian city of Astrakhan on the evening of June 7th, 2012. (Photo by Maxim Korotshenko)

#Resistiré 2020 (# I will resist 2020), the hymn recorded by more than 30 Spanish artists to beat the coronavirus together. Participating in the hymn: Alex Ubago, Andrés Suárez, Álvaro Soler, Blas Cantó, Carlos Baute, Conchita, David Bisbal, David Otero, David Summers, Despistaos, Diana Navarro, Dvicio, Mariposa Effect, Hall Effect, Ele, Georgina, India, Jose Mercé, Josemi Carmona, Manuel Carrasco, Melendi, Mikel Erentxun, Nil Moliner, Pastora Soler, Pedro Guerra, Pitingo, Rosana, Rozalén, Rulo, Sofía Ellar and Vanesa Martín. Promoted by Cadena 100, all these musicians and artists come together under the production of Pablo Cebrián to get this Resistiré, with which all funds will be for the benefit of Cáritas (Caritas Internationalis is a confederation of 165 Catholic relief, development and social service organizations operating in over 200 countries and territories worldwide. Collectively and individually, their claimed missions are to work to build a better world, especially for the poor and oppressed).

Rag pickers collect recyclable material at a garbage dump in New Delhi November 19, 2014. (Photo by Ahmad Masood/Reuters)