Oxygen.
use your brain
No one knows
it isnt easy its boring
dephlogisticated air is oxygen gas; - so called by Dr. Priestly and others of his time.
Joseph Priestly discovered "oxygen" in 1744. He called it "dephlogisticated air."
The gas is carbon dioxide.
Joseph Priestley was the man who first discovered oxygen, or as he called it "dephlogisticated air", back in the 18th Century
In 1809 Joseph Louis Gay-Lussac and Louis-Jacques Thénard tried to decompose dephlogisticated muratic acid air by reacting it with charcoal to release the free element muriaticum (and carbon dioxide). They did not succeed and published a report in which they considered the possibility that dephlogisticated muratic acid air is an element, but were not convinced. In 1810, Sir Humphrey Davy tried the same experiment again, and concluded that it was an element, and not a compound. He named this new element as chlorine, from the Greek word χλωρος (chlōros), meaning green-yellow
dephlogisticated muriatic acid
It derives from the French 'principe oxygene' which means 'acidifying principle'. The name was given because at the time it was thought that oxygen had to be present in an acid. The word was suggested by Antoine Lavoisier, the 'father of chemistry', though it was first isolated by Joseph Priestley. Priestly had called it 'dephlogisticated air' so I for one am very grateful to Lavoisier.
In 1809 Joseph Louis Gay-Lussac and Louis-Jacques Thénard tried to decompose dephlogisticated muratic acid air by reacting it with charcoal to release the free element muriaticum (and carbon dioxide). They did not succeed and published a report in which they considered the possibility that dephlogisticated muratic acid air is an element, but were not convinced. In 1810, Sir Humphrey Davy tried the same experiment again, and concluded that it was an element, and not a compound. He named this new element as chlorine, from the Greek word χλωρος (chlōros), meaning green-yellow