what were the existing theories before him?
The phlogiston theory
Carl Wilhelm Scheele
 the phlogiston theory
what is tropical storm arlene (1981)? It was a rare off-season tropical cyclone. what is the physical structure of this above type of cyclone just mentioned? Its formation was unusual, originating from a tropical disturbance that crossed from the eastern Pacific Ocean into the Caribbean Sea; few Atlantic hurricanes develop in this manner. what is the seasonal variation seen in this last mentioned hurricane? Approximately 97 percent of tropical cyclones that form in the North Atlantic develop between the dates of June 1 and November 30 and the official end has shifted from its initial date of October 31. what kind of intensity it has? It is determined by either the storm's maximum sustained winds or lowest barometric pressure. what are the steering factors of this hurricane? The surrounding flow throughout the depth of the troposphere, the atmospheric flow affects the path of a hurricane across the ocean etc what is the composition of the above mentioned sphere? Nitrogen, oxygen, argon, carbon dioxide etc what are some early experiments regarding the second mentioned gas? Relationship between combustion and air, air is necessary for combustion, fire requires only a part of air etc how did its discovery take place? Swedish pharmacist Carl Wilhelm Scheele produced oxygen gas by heating mercuric oxide and various nitrates in 1771–2. what theory did this above mentioned pharmacist invent? Theory of phlogiston what does this theory say in short? After Bergman informed the pharmacist about his findings, the pharmacist explained that saltpeter  had absorbed phlogiston with the heat and gave off a new phlogisticated gas as an active principle when combined with an acid.
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Carl Wilhelm Scheele [SEP] Existing theories before Scheele
By the time he was a teenager, Scheele had learned the dominant theory of gases which in the 1770s was the phlogiston theory. Phlogiston, classified as "matter of fire", was supposed to be released from any burning material, and when it was exhausted, combustion would stop. When Scheele discovered oxygen he called it "fire air" as it supported combustion. Scheele explained oxygen using phlogistical terms because he did not believe that his discovery disproved the phlogiston theory. Before Scheele made his discovery of oxygen, he studied air. Air was thought to be an element that made up the environment in which chemical reactions took place but did not interfere with the reactions.