In 1657, he was appointed professor of medicine at the University of Mainz and body-physician to the archbishop-elector. In 1666, he was made councillor of commerce (Commerzienrat) at Vienna, where he had gained the powerful support of Albrecht, Count Zinzendorf, prime minister and grand chamberlain of the emperor Leopold I. Sent by the emperor on a mission to the Netherlands, he wrote there in ten days his Methodus Didactica, which was followed by the Regeln der Christlichen Bundesgenossenschaft and the Politischer Discurs ...

See also:

J. J. Becher, J. J. Becher - Early life, J. J. Becher - Wandering scholar, J. J. Becher - Phlogiston

Read more here: » J. J. Becher: Encyclopedia II - J. J. Becher - Wandering scholar

The phlogiston theory is an obsolete scientific theory of combustion. It was developed by J. J. Becher late in the 17th century and was extended and popularized by Georg Ernst Stahl, who declared the rusting of metal to be a combustion process. Phlogiston theory - Theory. The theory holds that all flammable materials contain phlogiston (derived noun form of the Greek phlogistos, meaning flammable), a substance without color, odor, taste, or weight that is liberated in burning. Once burn ...

Including:

• Phlogiston theory - Theory
• Phlogiston theory - Challenge and demise
• Phlogiston theory - Bibliography

Read more here: » Phlogiston theory: Encyclopedia - Phlogiston theory

The caloric theory of heat is an obsolete scientific theory in thermodynamics, developed mostly during the 18th and 19th centuries. Caloric theory - History. In the history of thermodynamics, the initial explanations of heat were thoroughly confused with explanations of combustion. After J. J. Becher and Georg Ernst Stahl introduced the phlogiston theory of combustion in the 17th century, phlogiston was thought to be the substance of heat. The calorific theory was introduced by Antoine ...

Including:

• Caloric theory - History
• Caloric theory - Theory
• Caloric theory - Successes
• Caloric theory - Demise
• Caloric theory - Significance in the philosophy of science
• Caloric theory - Notes

Read more here: » Caloric theory: Encyclopedia - Caloric theory

The theory holds that all flammable materials contain phlogiston (derived noun form of the Greek phlogistos, meaning flammable), a substance without color, odor, taste, or weight that is liberated in burning. Once burned, the "dephlogisticated" substance was held to be in its "true" form, the calx. "Phlogisticated" substances are those that contain phlogiston and are "dephlogisticated" when burned. Since any substance could be observed to burn for only a limited time with limited air (for instance in a sealed container), air was thought ...

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Phlogiston theory, Phlogiston theory - Theory, Phlogiston theory - Challenge and demise, Phlogiston theory - Bibliography

Read more here: » Phlogiston theory: Encyclopedia II - Phlogiston theory - Theory

Eventually, quantitative experiments revealed problems, including the fact that some metals, such as magnesium gained weight when they burned, even though they were supposed to have lost phlogiston. Some phlogiston proponents explained this by concluding that it had "negative weight"; others, such as Guyton de Morveau, gave the more conventional argument that phlogiston was lighter than air. However, a more detailed analysis based on the Archimedean principle and the densities of magnesium and its combustion product shows that just being lig ...

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Phlogiston theory, Phlogiston theory - Theory, Phlogiston theory - Challenge and demise, Phlogiston theory - Bibliography

Read more here: » Phlogiston theory: Encyclopedia II - Phlogiston theory - Challenge and demise

In the history of thermodynamics, the initial explanations of heat were thoroughly confused with explanations of combustion. After J. J. Becher and Georg Ernst Stahl introduced the phlogiston theory of combustion in the 17th century, phlogiston was thought to be the substance of heat. The calorific theory was introduced by Antoine Lavoisier. Lavoisier had discovered the explanation of combustion in terms of oxygen in the 1770s. In his book Reflexions sur le phlogistique (1783), Lavoisier argued that phlogiston theory was inconsistent with his experimental results, and proposed ca ...

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Caloric theory, Caloric theory - History, Caloric theory - Theory, Caloric theory - Successes, Caloric theory - Demise, Caloric theory - Significance in the philosophy of science, Caloric theory - Notes

Read more here: » Caloric theory: Encyclopedia II - Caloric theory - History

The theory held that changes in temperature are due to the transfer of an imponderable fluid, invisible and weightless, called caloric. The theory originally hinged on two key assumptions: That heat was a 'self-repulsive' (or 'elastic', or 'expansive') substance, while it was attracted to ordinary matter; and That temperature was the density of caloric^{See also:}

Caloric theory, Caloric theory - History, Caloric theory - Theory, Caloric theory - Successes, Caloric theory - Demise, Caloric theory - Significance in the philosophy of science, Caloric theory - Notes

Read more here: » Caloric theory: Encyclopedia II - Caloric theory - Theory

In 1798, Count Rumford published An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction, a report on his investigation of the heat produced while manufacturing cannons. He had found that boring a cannon repeatedly does not result in a loss of its ability to produce heat, and therefore no loss of caloric. This suggested that caloric could not be a conserved "substance" though the experimental uncertainti ...

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Caloric theory, Caloric theory - History, Caloric theory - Theory, Caloric theory - Successes, Caloric theory - Demise, Caloric theory - Significance in the philosophy of science, Caloric theory - Notes

Read more here: » Caloric theory: Encyclopedia II - Caloric theory - Demise

Quite a number of successful explanations can be, and were, made from these hypotheses alone. We can understand why a cup of tea cools at room temperature: caloric is self-repelling, and thus slowly flows from regions dense in caloric (the hot water) to regions less dense in caloric (the cooler air in the room). We can explain the expansion of air under heat: caloric is absorbed into the molecules of air, which increases its volume. If we say a little more about what happens to caloric during this absorption phenomenon, we can explain the radiation of heat, the state changes of matter under various temperat ...

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Caloric theory, Caloric theory - History, Caloric theory - Theory, Caloric theory - Successes, Caloric theory - Demise, Caloric theory - Significance in the philosophy of science, Caloric theory - Notes

Read more here: » Caloric theory: Encyclopedia II - Caloric theory - Successes