Combustion Phlogiston theory

A. L. Lavoisier recognized oxygen as an element, developed the modem theory of combustion, and demolished the phlogiston theory. 

A more nearly correct theory of calcination and combustion had been proposed in the previous century. In 1630 the Frenchman Jean Rey theorized that the weight increase during calcination came about because air was incorporated into the calx. However, by the time the phlogiston theory was proposed, Rey s idea had been forgotten. It... 

The scientific revolution that began when Lavoisier announced his new theory of combustion was far from over. Chemists stuck to the phlogiston theory and some of them continued to cling to the old four-element theory as well, objecting that Lavoisier hadn t really shown that water could be decomposed. The hydrogen, they said, could have come from the hot iron over which the steam had been passed. 

Georg Ernst Stahl, 1660-1734. German chemist, physician, and professor. Co-founder of the phlogiston theory of combustion. Author of Fundaments Chymiae Dogmabcae et Expenmen-talis. He distinguished between potash and soda and recognized that alum contains a peculiar earth different from all others. 

Johann Joachim Becher, 1635-1682. German chemist and physician. Founder of the phlogiston theory. His experiments on minerals are described in his Physica Subterranea. Stahl summarized his views on combustion in a book entitled "Specimen Becherianum, ... 

M. and Mme. Lavoisier. In 1777 Lavoisier gave quantitative proof of the incorrectness of the phlogiston theory. Shortly after Priestley and Scheele discovered oxygen, Lavoisier gave the true explanation of combustion and respiration Ber-thollet, Guyton de Morveau, Fourcroy, and Klaproth were among the first to accept the new views. See also ref. (60)... 

Lavoisier overthrows the phlogiston theory and demonstrates the true nature of combustion. 

Stahl s phlogiston theory was elaborated to explain not just combustion but many other processes, including biological ones. It accounted for acids and alkalis, for respiration and the smells of plants. It was a chemical theory that, if not all embracing, at least gave the discipline an impressive unity. 

Theories of combustion, as they existed at the end of the seventeenth century and before the advent of the phlogiston theory of Stahl, may perhaps be advantageously considered here. 

The first period in the development of combustion science was a period of determination of the basic chemical facts to this period belong the refutation of the phlogiston theory and the discovery of oxygen, the discovery and study of the properties of carbon monoxide and carbon dioxide, and the so-called pneumatic chemistry —the investigation of various gases and determination of the stoichiometric laws (1650-1820). 

Daniel Bernoulli proposed the kinetic molecular theory for gases in the early 1700s to explain the nature of heat and Boyle s Law. At that time, heat was thought to be related to the release of a substance called phlogiston from combustible material. 

He provided an explanation of the heat and light produced in combustion as an alternative to the phlogiston theory. 

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