Whose discovery was oxygen?

Swedish pharmacist Carl Wilhelm Scheele produced oxygen by heating substances such as mercuric oxide around 1771–1772, calling it “fire air”, but his findings were not published until 1777. English clergyman Joseph Priestley made oxygen on 1 August 1774 by focusing sunlight on mercuric oxide, and published first, calling it “dephlogisticated air”. French chemist Antoine Lavoisier repeated the experiments and correctly explained that oxygen is an element involved in combustion and respiration. He named it oxygène in 1777, from Greek words meaning “acid former”, because he wrongly believed all acids contained it. His work overturned the old phlogiston theory.