Over 500 years ago, Leonardo da Vinci suggested that the air we breathe contains something vital to life, having found that combustion seemed to remove it from air, causing animals to suffocate. Many medieval alchemists tried to find it, without success. Then in 1774, the English chemist Joseph Priestley succeeded in both separating out the substance, and showing it was a single chemical element, rather than some special mix of gases. Priestley was also the first to publish his findings and thus allow others to confirm his discovery – a process which is still regarded as vital in claiming priority in discovery disputes.
The French chemist Antoine Lavoisier later claimed to have discovered the gas independently of Priestley. He named it oxygen (meaning ‘acid maker’), and investigated its properties. However, it’s known that Priestley had already shown Lavoisier how to make oxygen, undermining his claim.
Some historians argue that credit for discovering oxygen should go to the Swedish chemist Carl Scheele, who identified it several years before Priestley. Unfortunately, a letter he sent to Lavoisier describing his work never arrived, while his scientific report sat in a printer’s office for two years, ensuring his work was overshadowed by Priestley and Lavoisier.
- How does Earth maintain a constant level of oxygen?
- Is atmospheric oxygen declining, and does it matter?