Which element was named Dephlogisticated Air by its discoverer, the French chemist Lavoisier who gave it this common name?
Period 3 element by Swedish chemist Carl Wilhelm Scheele, who called it "dephlogisticated muriatic acid air," having thought he synthesized the oxide obtained from the hydrochloric acid, because acids were thought at the time to necessarily contain oxygen, a number of chemists, including Claude Berthollet, suggested that Scheele's dephlogisticated muriatic acid air must be a combination of oxygen and the yet undiscovered element, and Scheele named the supposed new element within this oxide as "muriaticum." The suggestion that this newly discovered gas was a simple element was made in 1809 by Joseph Louis Gay-Lussac and Louis-Jacques. This was confirmed by Sir Humphry Davy
Antoine Lavoisier his own. In addition to studying Priestley's dephlogisticated air, he studied more thoroughly the residual air after metals had been calcined. He showed that this residual air supported neither combustion nor respiration and that approximately five volumes of this air added to one volume of the dephlogisticated air gave common atmospheric air. Common air was then a mixture of two distinct chemical species with quite different properties. Thus when the revised version of the Easter Memoir was published in 1778, Lavoisier no longer stated that the principle which combined with metals on calcination was just common air but "nothing else