Skip to 0 minutes and 6 secondsDuring a lecture on his newly discovered alkali metals, Humphry Davy gave a dramatic demonstration as to the possible origin of the force of a volcanic eruption.
Skip to 0 minutes and 25 secondsKnighted just the day before, Sir Humphry gave his lecture to a packed audience right here in the lecture theatre of the Royal Institution, where a young Michael Faraday was sat at the back taking notes. Faraday's notebook, which he presented to Davy, is an important record since Davy himself did not leave accurate details of his demonstration lectures. This is Faraday's account of the lecture given by Davy on Friday the 10th April 1812, where he describes Davy's experiment
Skip to 0 minutes and 58 secondsto simulate the volcanic eruption: "It consisted of a miniature volcano. He had built upon a square board a pile of earth and stones in the form of a mountain crater.
Skip to 1 minute and 14 secondsOpenings and fissures were left in the top and the sides of this mountain in which was put pieces of the metal potassium. Sir Humphry Davy took a bottle of water and poured some of its contents into the fissures."
Skip to 1 minute and 54 secondsThe beauty and violence of this demonstration depends on the incredibly reactive metal potassium, that Davy had discovered just a few years before. This reaction with water produces the flammable gas hydrogen, and it also burns in the air with this beautiful purple flame.
Skip to 2 minutes and 27 secondsAlthough Davy suggested this might be a possible explanation for volcanic activity and earthquakes, we now know that this isn't due to such chemical reactions. Nevertheless, Davy's spectacular demonstrations illustrating natural phenomena, which very few members of the audience would have seen at the time, would have been extremely impressive. And it's little wonder that they contributed to his reputation as one of the most brilliant lecturers of the day.
Recreating Davy's 'Volcano'
Watch this video, in which Dr Peter Wothers reconstructs an experiment to demonstrate a volcano erupting using potassium, performed by Davy in the Royal Institution lecture theatre on 10 April 1812.
Please don’t try to recreate this experiment!
Dr Wothers explains that we only know so much about the experiment because Michael Faraday was in the audience of the lecture taking notes. Davy built a ‘volcano’ and used the newly isolated alkali metal potassium to investigate a theory he had about the force of volcanic eruptions.
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