The four-element theory

Pattison Muir, A History of Chemical Theories and Laws, p. vii. New York (1907). Partington, A Short History of Chemistry, 3rd ed.. Chapter 11, Dover Publications, New York 

The four-elements theory lasted well into the end of the eighteenth century, and the concept of the ether as a medium for the transmission of light lasted to the end of the nineteenth century The remarkable longevity of the four-element theory for several millennia highlights the lack of a chemical proof that earth, water, air, and fire were elements, or that nature s enormous variety of materials were made up of only four substances. To the ancient mind, the theory helped to explain many facts in ways that were easily understood. 

Applying Aristotle s theory to medicine, Galen of Pergamos (129-199 AD) proposed that in a healthy body, the four elements, which appear as four humors (blood, phlegm, bile, and black bde) are in equilibrium (an idea going back to Anaxogoras, 450 BC). Disease, he said, is caused by the predominance of an element and is cured by the opposite element.  

Partington, A Short History of Chemistry, 3rd ed., pp. 13 14, Dover Publications, New York 

---

Boyle expounded no alternative theory in The Sceptical Chymist. He concerned himself mainly with fostering skepticism about the Aristotelian and Paracelsian chemical philosophies. But the book is a science classic nevertheless. Little progress could be made in chemistry until those theories were overthrown. To be sure, Boyle failed to accomplish this and belief in the four-element theory, especially, lingered on for quite a long time. However, Boyle showed that it was possible to doubt long-established ideas, thus performing a great service to science. 

When Lavoisier s career as a chemist began, the four-element theory was still widely believed. It was Lavoisier who showed how implausible it really was and who correctly identified many of the elements. He demolished one commonly held belief about water quite early in his career. At the time, it was commonly thought that water could be transmuted into earth. After all, watering plants made them grow. It appeared that water was being transformed into a solid substance. 

It was a simple picture of matter, as simple as the four-element theory with which chemistry had begun. And it was just as wrong. In fact, in 1925 physicists were already beginning to realize that there were serious problems with this model. For example, the electron was supposed to be approximately the same size as atomic nuclei. How could one confine numerous electrons in so small a space Uranium, for example, was supposed to have 238 protons and 146 electrons within the nucleus. 

Not until the sixteenth century did questions about the ultimate nature of things began to be asked again. Although the four-element theory continued to be accepted, new attempts were made to better... 

However, before we can provide a full summary of chemistry in France prior to the chemical revolution of the 1770s, we need to present two other topics in early eighteenth century chemistry the return of air, and the revival of the four element theory that had been largely invisible among French chemical writers for more than a century. 

Aristotle continued and extended the four-element theory of matter. His definition of an element can be found in De caelo, where he says ... 

In spite of the fact that the phlogiston theory made it possible for a large number of facts to be coordinated into a system, it nevertheless retarded the progress of chemistry and prevented a number of the best chemists from seeing the correct explanation of the facts they uncovered. So until it, along with the four-element theory, were comprehensively rejected, modem chemistry remained unfounded for earth, air, water, and fire are not the elements, and substances do not bum because of the presence in them of a common principle of inflammability. 

The four elements are not the same as the substances with the same name that occur on Earth. The primary elements can be combined in any proportion to produce the known variety of homogeneous substances. Whereas the four elements are in constant interaction with each other and hence interconvertible, heavenly bodies do not consist of earthly elements, are immutable, circle the Earth on perfect orbits and consist of quintessence, the fifth heavenly element. The alchemists adopted the four-element theory, which offered the possibility of transmutation of metals. As even the elements can be interconverted the same must be true for metals, which are homogeneous bodies and, although not elements, are made up of the four elements. The Arabian alchemist Ibn Sina (Avicenna), who questioned the transmutation of metals, explained that metals are formed by the combination of sulphur (air - - water) and mercury (fire - - earth), which derive from the four elements. In order to make the theory applicable, not only to metals, but to all substances, Paracelsus added salt as the third element of alchemy. Again, his tria print,a of salt (body), sulphur (soul), and mercury (spirit) are not... 

This incommensurable relationship between polygons and the limiting circle reflects the unbridgeable gap between gods and humans, interpreted to demonstrate that heavenly bodies move in perfect circles and differ from earthly objects in composition. Alchemy, astrology, the Aristotelean model of the cosmos and the four-element theory assume a hidden mystical link between heaven and earth, only revealed through pure belief in its magic. 

The four-element theory would make it seem that the various substances of the universe differed only in the nature of the elemental mixture. This hypothesis would be true whether one accepted the atomist view or not, since the elements could mix as atoms or as continuous substance. Indeed, there seemed reason to think that even the elements themselves were interchangeable. Water seemed to turn to air when it evaporated, and the air turned back to water when it rained. Wood, if heated, turned to fire and vapors (a form of air) and so on. 

There is a long history for us to recognize polymers. Let us start with the early evolution of our molecular views (Rupp 2005). As early as in the middle of 500 BC, the Greek philosopher Leucippus and his follower Democritus suggested that, an indivisible minimum substance called atoms constituted our world. Almost at the same time, Empedocles proposed that the world was formed by four elements, i.e., water, air, fire, and earth. Later on, Plato set up the Academy at Athens, inherited the atomic theory, and also advocated the four-element theory on the basis of the formal logic system of geometries. 

A third important school of thought that influenced the philosophies of Athens was that of Empedocles. It is difficult to decide with what trumpet blast to announce this name, but let it suffice to say that Empedocles was the originator of the four-element theory of matter— another idea that dominated Arabic and European chemical thought until the close of the 1700s. 

Philosopher Empedocles (Greece) introduces the four-element theory of matter (fire, air, water, earth). [450 BCE]... 

In Chap. 3, Jo Hedesan addresses Boyle s Sceptical Chymist as a case study for theory choice in the 17th cenmry. The original discussion focuses on three competing theories concerning the chemical components of matter the four-element theory of Aristotle, the three-principle theory of Paracelsus and the atomistic theory. Hedesan argues, that in effect the book is an attack on Paracelsianism by Boyle. This is evident from the fact that the other two theories fall out of the discussion quite early in the text. In the history of Chemistry, this seminal text is often taken as a successful attack on Paracelsianism. 

---