Individuals and populations student winner. Limbing in the Tropics, photographed in Manaus, Brazil. While walking in the Amazon rainforest looking for bat roosts to set up mist nets to capture bats for scientific research, a faint and almost imperceptible noise suddenly caught this photographer’s attention. An anteater was climbing with exceptional ability in a tangled mess of branches and lianas. (Photo by Adrià López Baucells/University of Lisbon/British Ecological Society)

A homeless man sleeps against a wall adorned with a mural featuring a Shipibo Indigenous girl and Amazon rainforest animals, in Pucallpa, in Peru's Ucayali region, Wednesday, September 2, 2020. Peru is home to one of Latin America's largest Indigenous populations, whose ancestors lived in the Andean country before the arrival of Spanish colonists. (Photo by Rodrigo Abd/AP Photo)

Raissa Floriano whose father is hospitalized with CCOVID-19, cries during a protest amid the new coronavirus pandemic outside the 28 Agosto Hospital, in Manaus, Brazil, Thursday, January 14, 2021. Scores of COVID-19 patients in the Amazon rainforest's biggest city will be transferred out of state as the local health system collapses and dwindling stocks of oxygen tanks begin to falter. (Photo by Edmar Barros/AP Photos)

A fisherman carries a large Pirarucu (Arapaima gigas) at the Piagacu-Purus Sustainable Development Reserve in Amazonas state, Brazil, on October 24, 2019. The pirarucu -a giant fish of the Amazon, that had been on the verge of extinction- can measure up to three meters and weigh more than 200 kilos. The soft and tasty white meat fish is nowadays served in renowned restaurants in Rio de Janeiro. (Photo by Ricardo Oliveira/AFP Photo)

An Emperor Tamarin monkey, native to the Amazon rainforest, experiences its new home in the living rainforest enclosure at ZSL London Zoo on March 25, 2010 in London, England. Entitled “Rainforest Life” the large temperature and humidity controlled bio-dome is home to free-roaming monkeys, sloths, tree anteaters and tropical birds. The exhibit, which is opening in the International Year of Biodiversity, will be open to the public from March 27, 2010. (Photo by Oli Scarff/Getty Images)

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 police officer walks along a street of the burning village of Smolenka near Chita on Monday, April 13, 2015. Russian authorities say out-of-control agricultural fires have killed at least 15 people, injured hundreds more and destroyed or damaged more than 1,000 homes in Siberia. The fires were started by farmers burning the grass in their fields, but spread quickly because of strong winds. (Photo by Evgeny Yepanchintsev/AP Photo)

Satirical sculptures burn during the traditional Fallas festival in Valencia, Spain, on March 19, 2014. Every year the city celebrates the ancient “Las Fallas” fiesta, a noisy week that is full of fireworks and processions in honor of Saint Joseph that ends on midnight of March 19, burning large satiric figures displayed around the streets of the city. (Photo by Alberto Saiz/Associated Press)