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Who discovered chlorine gas in 1774?

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A labeled diagram of the chlorine element from the periodic table shows its atomic number 17, symbol Cl, electron configuration, and atomic weight range. The box is shaded green to indicate chlorine is a halogen, with icons for orthorhombic crystal structure, gas state at room temperature, and strong acidity. A key explains the icons and colors used. — chlorine Properties of chlorine.

The Swedish chemist Carl Wilhelm Scheele discovered chlorine gas in 1774.12

He produced the gas by treating powdered black manganese oxide with hydrochloric acid. At the time, Scheele failed to recognize the substance as a chemical element, instead identifying it as "dephlogisticated muriatic acid" based on the prevailing phlogiston theory. It was not until 1810 that the English chemist Humphry Davy demonstrated that the gas was an element and gave it the name chlorine, derived from the Greek word chloros, meaning "yellowish green".213