Theory
"Phlogisticated" substances are those that contain phlogiston and are "dephlogisticated" when burned; "in general, substances that burned in air were said to be rich in phlogiston; the fact that combustion soon ceased in an enclosed space was taken as clear-cut evidence that air had the capacity to absorb only a definite amount of phlogiston. When air had become completely phlogisticated it would no longer serve to support combustion of any material, nor would a metal heated in it yield a calx; nor could phlogisticated air support life, for the role of air in respiration was to remove the phlogiston from the body."
Thus, phlogiston was described in a way that was basically the opposite of the role of oxygen in combustion.
Joseph Black's student Daniel Rutherford discovered nitrogen in 1772 and the pair used the theory to explain his results. The residue of air left after burning, in fact a mixture of nitrogen and carbon dioxide, was sometimes referred to as "phlogisticated air", having taken up all of the phlogiston. Conversely, when oxygen was first discovered it was thought to be "dephlogisticated air", capable of combining with more phlogiston and thus supporting combustion for longer than ordinary air.
Read more about this topic: Phlogiston Theory
Famous quotes containing the word theory:
“It is not enough for theory to describe and analyse, it must itself be an event in the universe it describes. In order to do this theory must partake of and become the acceleration of this logic. It must tear itself from all referents and take pride only in the future. Theory must operate on time at the cost of a deliberate distortion of present reality.”
—Jean Baudrillard (b. 1929)
“The struggle for existence holds as much in the intellectual as in the physical world. A theory is a species of thinking, and its right to exist is coextensive with its power of resisting extinction by its rivals.”
—Thomas Henry Huxley (1825–95)
“The theory of rights enables us to rise and overthrow obstacles, but not to found a strong and lasting accord between all the elements which compose the nation.”
—Giuseppe Mazzini (1805–1872)