Two men using an electric power saw to fell a tree circa 1940's. (Photo by Keystone View/FPG/Getty Images)

Four men dressed as zombies participate in a Zombie Walk procession in the streets of Paris October 12, 2013. (Photo by Benoit Tessier/Reuters)

Men work on a large hookah at the Taha factory in Baghdad, Iraq July 2, 2016. (Photo by Khalid al Mousily/Reuters)

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.

These stunning images document the everyday lives of the men, women and children of the Mentawai tribe. The Mentawai people, a native population in Indonesia, are famous for their decorative tattoos and for living a semi-nomadic life on the Mentawai Islands in West Sumatra. Shot by professional photographer Mohammed Saleh Bin Dollah, the series captures a glimpse of life on the island as the Mentawai men smoke and hunt for food and the children play in the river. Here: A young boy helps a woman to prepare food taken on July 19, 2014 on the Mentawai Islands, Indonesia. (Photo by Muhamad Saleh Dollah/Barcroft Media)

Maasai men of Matapato jostle to parade as they attend the Olng'esherr (meat-eating) passage ceremony to unite two age-sets; the older Ilpaamu and the younger Ilaitete into senior elderhood as the final rite of passage, in Maparasha hills of Kajiado, Kenya on September 23, 2020. Thousands of Maasai men clad in red and purple shawls and with their heads coated in red ochre gathered this week for a ceremony that transforms them from Moran (warriors) to Mzee (elders). (Photo by Thomas Mukoya/Reuters)

Men selling sheep wait for customers at a local livestock market, ahead of the Eid al-Adha festival, in Lagos, Nigeria September 11, 2016. (Photo by Akintunde Akinleye/Reuters)