Does Sendivogius’ Alchemy Cancel the Celebration of the 250th Anniversary of the Discovery of Oxygen?

Most chemistry textbooks claim that oxygen was discovered almost simultaneously by Carl Scheele and Joseph Priestley about 250 years ago. Priestley obtained oxygen by heating mercuric oxide (1774), and Scheele -by heating NaNO₃, as well as by dissolving pyrolusite in sulfuric acid (1772). The name “oxygen” was given a few years later (1779) by Antoine Lavoisier. This great scientist, often accused of taking advantage of the discoveries of others, conducted experiments related to the decomposition of water vapour over heated iron, as well as the synthesis of water from hydrogen and oxygen. His work was of great importance because it revealed the elemental nature of oxygen and its role in the processes of combustion and respiration. The present article draws attention to the prehistory of the “oxygen theory”. It emphasises the natural philosophy of a forgotten alchemist, healer, and diplomat - Michael Sendivogius (1566-1636) - who popularised his belief that the substance (“Water of life that does not wet the hands”) obtained by heating the “Central Salt” (nitre, KNO₃) is part of the air. It is the “secret food of life” used invisibly by every living thing.