Georg Ernest STAHL( German physician and chemist)
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Biography Georg Ernest STAHL
Stahl, Georg Ernst (Stahl, Georg Ernst) (1659-1734), German physician and chemist, creator of the theory of phlogiston. Born October 21, 1659 (other sources - the same number 1660) in Ansbach. In 1673-1679 he studied medicine and chemistry at the University of Jena, was there as assistant professor, then professor of medicine. Since 1687 - the court doctor of the Duke of Saxony-Weimar Johann Ernst. In 1694 he was elected professor of medicine just opened the University of Halle. Taught foundations of medicine and worked in the clinic, conducted extensive theoretical and experimental research in the field of chemistry. In 1715 he was invited to Berlin for the post of court physician of the Prussian King Friedrich Wilhelm I. Became president of the Medical Association - higher medical institutions of Prussia. Thanks to his efforts in Berlin was founded Medico-Surgical College for training military doctors.
In the history of chemistry Stahl came as the author of the theory of phlogiston (from the Greek. flogistos, flammable). The term still occurs in Aristotle, and then a number of doctors and chemists of the Middle Ages, but the first sketch of the teachings of one of the 'beginning' of the macrocosm, 'inflammable earth', gave predecessor Stahl Johannes R. Becher. According to Stahl, all combustible bodies, as well as metals contain a general introduction - phlogiston, which is lost during firing of metals and burning of bodies. Metals at the same time become dross, and the body - in the 'lime'. If these 'deflogistirovannye' education ignited with coal, rich in phlogiston, then they will return its phlogiston, and once again become metals. Further, according to Stahl, phlogiston released during combustion in the air, where the 'perceived' plants and from them goes to the animals. Here he is involved in the processes of respiration, fermentation, putrefaction.
Thus, Stahl believed metals complex bodies (calx + phlogiston) and scale (oxides in the modern sense) - simple. Expansion in the modern sense (the transformation of oxide into the metal), from the perspective of supporters of phlogiston, a process connection, and oxidation (compound of the metal with oxygen) - decomposition. And although the theory of phlogiston in all redox processes are considered 'opposite', . she became the first generalizing the concept of scientific, . helps not only to explain the many observations, . but sometimes make discoveries (eg, . the idea of phlogiston used Lovitz, . opened carbon adsorption of dissolved substances),
Phlogiston theory dominated until 1770-ies, and the pursuit of this matter led to the establishment of many new facts and new chemicals. Based on theoretical assumptions of the theory, it was possible to understand the characteristics of metallurgical processes and improve the quality of melted metal. And most importantly - the experimental facts obtained during the dominance of the ideas of phlogiston, Lavoisier helped identify Priestley obtained oxygen from the real antithesis to create oxygen and phlogiston theory
. Stahl's ideas were set out in numerous works - "Foundations zimotehniki, . or the general theory of fermentation "(Zimotechnica fundamentalic seu Fermentationis theoria generalis, . 1697), . "Becher example" (in addition to the Underground physics Becher) (Specimen Becherianum, . 1723), . "Foundations of dogmatic and Experimental Chemistry" (Fundamenta Chymiae dogmaticae et experimentalis, . 1723),
. Stahl also belong to the work on mining, metallurgy, the art of assaying.
Stahl died in Berlin on May 14, 1734.