Michal Sedziwój

Michael Sendivogius was a Polish alchemist, philosopher, and medical doctor. A pioneer of chemistry, he developed ways of purification and creation of various acids, metals and other chemical compounds. He discovered that air is not a single substance and contains a life-giving substance—later called oxygen—170 years before Scheele's discovery of the element. He correctly identified this "food of life" with the gas given off by heating nitre (saltpetre). This substance, the "central nitre", had a central position in Sendivogius' schema of the universe.