The History Of Oxygen
Oxygen is a chemical element with symbol O and atomic number 8. One of the first known experiments on the relationship between combustion and air was conducted by the 2nd century BCE Greek writer on mechanics, Philo of Byzantium. Many centuries later Leonardo da Vinci built on Philo's work by observing that a portion of air is consumed during combustion and respiration. In the late 17th century, Robert Boyle proved that air is necessary for combustion. Robert Hooke, Ole Borch, Mikhail Lomonosov, and Pierre Bayen all produced oxygen in experiments in the 17th and the 18th century but none of them recognized it as a chemical element. Oxygen was first discovered by Swedish pharmacist Carl Wilhelm Scheele. He had produced oxygen gas by heating mercuric oxide and various nitrates by about 1772. on August 1, 1774, an experiment conducted by the British clergyman Joseph Priestley focused sunlight on mercuric oxide inside a glass tube, which liberated a gas he named "dephlogisticated air". He noted that candles burned brighter in the gas and that a mouse was more active and lived longer while breathing it. Priestley is usually given priority in the discovery because he published his findings first. Another scientist named Lavoisier proved that air is a mixture of two gases: vital air, which is essential to combustion and respiration, and azote, which is now called Nitrogen in English and did not support either. Lavoisier renamed 'vital air' to oxygène in 1777 from the Greek roots ὀξύς “oxys” and -γενής “-genēs”. Oxygen entered the English language despite opposition by English scientists. This substance is an important part of the atmosphere, and is necessary to sustain most terrestrial life.