The Modern Phlogiston Concept

Leicester and H.S. Klickstein, A Source Book In Chemistry 1400—1900, McGraw-Hill, New York, 1952, pp. 55-58. 

This figure, from the book Oedipus Chymicus, is from Science and Technology Catalog 5 Jeremy Norman, San Francisco, 1978, p. 13. Courtesy of Jeremy Norman Company, Inc. 

MacPhail, Alchemy and the Occult, Yale University Library, New Haven, 1968, Vol. 2, pp. 472-476. 

Phlogiston was postulated to be present in substances that could burn as well as in metals, which were known to form calxes. The concept works like this  

Aside from relating these two seemingly very different kinds of chemistry, it explained the well-known ability to convert calxes into metals by heating with charcoal  

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