Georg Ernst Stahl (nonfiction)

Georg Ernst Stahl.

Georg Ernst Stahl (22 October 1659 – 24 May 1734) was a German chemist, physician and philosopher. He was a supporter of vitalism, and until the late 18th century his works on phlogiston were accepted as an explanation for chemical processes.

Stahl's focus was on the distinction between the living and nonliving. Although he did not support the views of iatro-mechanists, he believed that all non-living creatures are mechanical and so are living things to a certain degree. His views were that nonliving things are stable throughout time and did not rapidly change. On the other hand, living things are subject to change and have a tendency to decompose, which led Stahl to work with fermentation.

Stahl professed an animistic system, in opposition to the materialism of Hermann Boerhaave and Friedrich Hoffmann. His main argument on living things was that there is an agent responsible for delaying this decomposition of living things and that agent is the anima or soul of the living organism. The anima controls all of the physical processes that happen in the body. It not only just controls the mechanical aspects of it but the direction and goals of them too. How the anima controls these processes is through motion. He believed that the three important motions of the body are the circulation of blood, excretion and secretion.

These beliefs were reflected in his views on medicine. He thought that medicine should deal with the body as a whole and its anima, rather than the specific parts of a body. Having knowledge on the specific mechanical parts of the body is not very useful. His views had been criticized by Gottfried Leibniz, with whom he exchanged letters, later published in a book titled Negotium otiosum seu σκιαμαχία (1720).

The best of Stahl’s work in chemistry was done while he was a professor at Halle. Just like medicine, he believed that chemistry could not be reduced to mechanistic views. Although he believed in atoms, he did not believe that atomic theories were enough to describe the chemical processes that go on. He believed that atoms could not be isolated individually and that they join together to form elements. He took an empirical approach when establishing his descriptions of chemistry.

Stahl used the works of Johann Joachim Becher to help him come up with explanations of chemical phenomena. The main theory that Stahl got from J. J. Becher was the theory of phlogiston. This theory did not have any experimental basis before Stahl. He was able to make the theory applicable to chemistry. Becher's theories attempted in explaining chemistry as comprehensively as seemingly possible through classifying different earths according to specific reactions. Terra pinguis was a substance that escaped during combustion reactions, according to Becher. Stahl, influenced by Becher's work, developed his theory of phlogiston. Phlogiston theory did not have any experimental basis before Stahl worked with metals and various other substances in order separate phlogiston from them. Stahl proposed that metals were made of calx, or ash, and phlogiston and that once a metal is heated, the phlogiston leaves only the calx within the substance.He was able to make the theory applicable to chemistry as it was one of the first unifying theories in the discipline. Phlogiston provided an explanation of various chemical phenomena and encouraged the chemists of the time to rationally work with the theory to explore more of the subject. This theory was later replaced by Antoine-Laurent Lavoisier’s theory of oxidation. He also propounded a view of fermentation, which in some respects resembles that supported by Justus von Liebig a century and half later. Although his theory was replaced, Stahl's theory of phlogiston is seen to be the transition between alchemy and chemistry.

Nonfiction cross-reference

• Johann Joachim Becher (nonfiction)

External links:

• Georg Ernst Stahl @ Wikipedia

Attribution: