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.

“Hayley Dee Westenra (born 10 April 1987) is a New Zealand soprano, classical crossover artist, songwriter and UNICEF Ambassador. Her first internationally released album, Pure, reached #1 on the UK classical charts in 2003 and has sold more than two million copies worldwide. Pure is the fastest-selling international début classical album to date, having made Westenra an international star at age 16. In August 2006, she joined the Irish group Celtic Woman, was featured on their Celtic Woman: A New Journey CD and DVD, toured with them on their 2007 Spring Tour, and also was featured on their DVD, The Greatest Journey: Essential Collection, released in 2008”. – Wikipedia

Photo: The world's biggest-selling soprano, Hayley Westenra, has today been announced as the voice of ITV's coverage of this years Rugby World Cup, with her version of “World In Union”. The multi-million selling artist releases her fifth album, “Paradiso”, that has been produced by film composing legend Ennio Morricone, on 29th August. (Photo by Gareth Cattermole/Getty Images)

Snakes are collected and rolled before putting into the oven on March 2, 2014 in the village of Kertasura, Cirebon, Indonesia. At slaughter house snake skins measuring in the hundreds of metres, are sold to bag factories in the West and Central Java provinces on a monthly basis. From snake skin was manufactured into bags, shoes, wallets and belts. The price of a bag made from snake skin costs between 150,000 rupiah ($15 USD) and 300,000 rupiah ($30 USD), depending on its size. When snake skins reach Western fashion houses their price can increase dramatically and sell for up to $4,000 USD. (Photo by Nurcholis Anhari Lubis/Getty Images)

“Amphilophus citrinellus is a large cichlid fish endemic to the San Juan River and adjacent watersheds in Costa Rica and Nicaragua. In the aquarium trade A. citrinellus is often sold under the trade name of Midas cichlid. A. citrinellus are omnivorous and their diet consists of plant material, molluscs and smaller fish”. – Wikipedia

Photo: Two Midas Cichlid (lat: amphilophus citrinellus) fish are seen in an aquarium at Hellabrunn zoo on December 23, 2009 in Munich, Germany. (Photo by Alexandra Beier/Getty Images)

A woman holds a hedgehog at the Harry hedgehog cafe in Tokyo, Japan, April 5, 2016. In a new animal-themed cafe, 20 to 30 hedgehogs of different breeds scrabble and snooze in glass tanks in Tokyo's Roppongi entertainment district. Customers have been queuing to play with the prickly mammals, which have long been sold in Japan as pets. The cafe's name Harry alludes to the Japanese word for hedgehog, harinezumi. (Photo by Thomas Peter/Reuters)

Inspired by traditional Indian travelling photography studios, Arthur Crestani photographed the inhabitants of Gurgaon, a city built almost entirely by private companies. Arthur Crestani’s “Bad City Dreams” contrasts the glossy ideal sold by developers with urban reality. Here: Luxury Living Bhiwadi: “Sky Club on 18th Floor”. (Photo by Arthur Crestani/The Guardian)

Goyo, an eight-month-old mini pig, plays with a dog in Mexico City, December 21, 2015. Mini pigs can grow to about 30 kg (66.1 lbs) in weight and about 35 cm (1.1 ft) in height, according to the company Mini Pigs Mexico. The company says that the mini pigs' popularity as pets is growing and around 300 are sold every year in Mexico, with prices ranging from $350 to $1,600. (Photo by Edgard Garrido/Reuters)

Completion is near on Monaco's tallest skyscraper ever, and its first new one since the 1980s. Fueled by a luxury-housing boom in the tax-haven nation, the Odeon Tower's so-called Sky Penthouse is expected to sell for more than any other apartment in the world has ever sold before. Photo: The five-story Sky Penthouse is expected to be complete in September 2015. The water slide extends from a dance floor in the residence down to a private infinity pool. (Photo by Tour Odeon)