Fire Air Oxygen Who Knew What and When Did They Know It

The Development of Modern Chemistry, Harper Row, New York, 1964, pp. 40-50. 

Poirier, Lavoisier—Chemist, Biologist, Economist, R. Balinski (translator). University of Pennsylvania Press, Philadelphia, 1996, pp. 51-54. 

FIRE AIR (OXYGEN) WHO KNEW WHAT AND WHEN DID THEY KNOW IT  

The Uppsala period (1770-1775) was one of incredible productivity for Scheele. He made numerous important discoveries, but his discovery of oxygen in 1771 or 1772 (possibly even earlier) is considered his single greatest work. It is important to remark that Joseph Priestley independently discovered oxygen in 

Scheele made a number of other extremely valuable contributions to chemistry. He added oil of vitriol to fluorspar (CaF ) and distilled it. He found extensive corrosion of the retort containing the reaction mixture all the luting used to seal the apparatus was now brittle and friable, and a white deposit was formed on all interior surfaces of the apparatus. Scheele had formed hydrofluoric acid (HE), which attacked the glass vessel (silicon dioxide) and formed gaseous SiF. When he duplicated the experiment but added water to the receiver, he was surprised to find a layer of gelatinous silica on top of the water. 

---