What is the phlogiston theory? – Discover the phlogiston postulates
The phlogiston theory is a chemical theory that sought to explain the combustion process through the presence of a substance in bodies, known as ‘phlogiston’. This theory was proposed by the alchemists Johann Joachim Becher and Georg Ernst Stahl in the year 1667. Are you interested in knowing what this theory is? Stay here and find out what it is about and much more, here we show you!
What does the term “phlogiston” mean?
the phlogiston is part of a chemical theory, already refuted, which is based on the existence of a chemical element called “phlogiston”, which was found within the combustible bodies, and could be released through combustion. This theory tried to explain how the combustion process worked, as well as that of oxidation.
This first theory of modern chemistry was postulated in the 18th century by the alchemist Johann J. Becher, being perfected by the physician Georg Ernst Stahl. Both were looking for a way to explain how did combustion work through the loss of the phlogiston element.
However, the theory was abandoned at the end of the century thanks to the experiments of Antoine Lavoisier, which managed to better explain how combustion worked. Thus, in 1783 a document was published that allowed to demonstrate the inconsistency of this theoryachieving, in this way, ruling out that the loss of mass of any solid that was exposed to fire was phlogiston.
To do this, Lavoisier conducted an experiment with two metals and one non-metal: lead, tin, and sulfur. He placed each of them under fire and examined their masses, discovering that the residue of the mass of each of these objects, after they were calcined, was even greater than the initial one. In this way, he verified that, if the phlogiston theory were to be applied, its weight in metallic elements would be negative, being completely absurd.
This investigation allowed numerous important experiments to be carried out, and among them was the one that allowed one of the chemical elements was discovered most important of the periodic table: the Oxigen.
What is the history of the phlogiston theory?
In 1667 he was first postulated the phlogiston theory at the hands of the German alchemist Johann Becher, who tried to impose a particular and unique version of the theory of the four elements. In it, he mentioned that there were only two elements: earth and water. On the other hand, air and fire were only agents of transformations.
Therefore, it is that all the bodies, according to Becher, were found made by mixing earth and water. Likewise, he maintained that minerals were made up of three different types of land, each of them carrying a certain property. Among them, we find the ability to be volatile or fluidity that it may have, its combustible nature and its glassy appearance.
Through this information, what was known as ‘terra pinguis’, an element that provided sulfurous or combustible properties. Becher’s disciple was the one who led this theory, because with what his teacher had raised, Georg Stahl declared that metals were nothing more than phlogiston-containing compounds, which allowed them to be flammable. For example, he defined that wood was nothing more than a combination of phlogiston and ash, in the same way he said that soot was almost pure phlogiston.
Who created the phlogiston theory? – Father of theory
The phlogiston theory was created by Johann Joachim Becher, a German physicist, chemist and alchemist. Because he mentioned and included the principle of flammability within modern chemistry, through his observations and analysis, he proposed that when one substance ignites, another substance at the same time is released. This last substance she baptized under the name of “terra pinguis“.
The individual who finished creating and giving foundations to the phlogiston theory was Georg Ernst Stahl, who years later would postulate it.
What does the phlogiston theory say?
The phlogiston theory mentions that substances containing “phlogiston” go through a “dephlogistication” process when burned. That is, every time they go through a combustion process, all the phlogiston will be released that was stored inside the body, which will be previously absorbed by the air.
In this way, the plants will then take in the phlogiston through their respiration, so that air cannot spontaneously burn. In addition, that this was the quality that allowed the manner and organisms of the Kingdom Plantae, in general, to burn so easily.
As can be seen, it is more than clear that this theory is completely opposed to the oxygen theory.