Joseph Priestley and the Discovery of Oxygen.
Equipment used by Joseph Priestley in his experiments on gases. On February 6 1804 English theologian, Dissenting clergyman natural philosopher chemist educator and Liberal political theorist Joseph Priestley passed away. Being a rather prolific author with more than 150 works published, he is usually credited with the discovery of oxygen having isolated it in its gaseous state although Carl Wilhelm Scheele and Antoine Lavoisier also have a claim to the discovery. Joseph Priestley attended local schools and learned Greek Latin and Hebrew because he was intended for the ministry Later on, Priestley also studied languages including French Italian and German as well as Aramic and Arabic Also, he was introduced to mathematics natural philosophy logic and metaphysics through the works of Isaac Watts Willem's. Gravesande and John Locke Priestley was educated at Daventry a Dissenting academy and spent most of his life employed as a preacher or teacher. However, he gradually came to question the divinity of Jesus while accepting much else of Christianity the process becoming an early Unitarian 'The History of Electricity' was Priestley's first known scientific work and for this achievement, he was made Fellow of the Royal Society It is believed that he had been inspired by Benjamin Franklin whom he met in London Priestley began performing experiments in order to reproduce those reported in scientific works and later on he started answering some questions on his own. Priestley became interested in the research of nature and gases. Since he was living next to a brewery Priestley was able to obtain a great supply of carbon dioxide. In his first known publication on the topic, Joseph Priestley described how to carbonate water in imitation of some naturally occurring bubbly mineral waters Probably inspired by the works of Stephen Hales Priestley started examining the 'airs' that may be released from different substances. He managed to isolate and characterize about eight gases including oxygen Priestley is also credited with important contributions to the understanding of photosynthesis. He proved that plants somehow change the composition of the air. In one of his famous experiments, Priestley kept a mouse in a jar of air until it collapsed and he found out that a mouse that was kept with a plant would survive. He developed the hypothesis that plants restore to the air whatever breathing animals and burning candles remove. [2, 3]. One of Priestley's most famous experiment was performed in 1774. He used a 12-inch-wide glass "burning lens" and focused sunlight on a lump of reddish mercuric oxide in an inverted glass container placed in a pool of mercury. As a result, the gas emitted and he found it "five or six times as good as common air". After further tests, Priestley called his discovery "He explained that it supported combustion so well because it had no phlogiston in it, and hence could absorb the maximum amount during burning. However, the Swedish apothecary Carl Wilhelm Scheele isolated the same gas and observed a similar reaction Scheele called his material "but he did not publish his findings until 1777 . At yovisto, you may enjoy a video lecture by Professor McBride called “Oxygen and the Chemical Revolution” at Yale University in 2008.