Four-element theory

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. 

The scientific revolution that began when Lavoisier announced his new theory of combustion was far from over. Chemists stuck to the phlogiston theory and some of them continued to cling to the old four-element theory as well, objecting that Lavoisier hadn t really shown that water could be decomposed. The hydrogen, they said, could have come from the hot iron over which the steam had been passed. 

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... 

The Greek philosophers coupled a four-element theory to the idea of four primary colours to Empedocles these were white, black, red, and the vaguely defined ochron, consistent with the preference of the classical Greek painters for a four-colour palette of white, black, red, and yellow. The Athenian astrologer Antiochos in the second century ad assigned these colours, respectively, to water, earth, air, and fire. 

The conventional four-element theory claimed that all four of Aristotle s elements are present in all substances. But Boyle observes that some materials cannot be reduced to the classical elementary components, however they are manipulated by Vulcan , the heat of a furnace ... 

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. 

In particular, Rouelle adopted Boerhaave s view of elements as constituents and instruments and developed a sort of operationalist matter theory. He presented his four-element theory under the heading of instruments. This lesson included four natural instruments - fire, air, water, and earth - and two artificial instruments... 

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

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. 

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 progress of science is often hampered by the reputation of great scientists. During his lifetime the Greek philosopher Aristotle (384-322 BCE) acquired a reputation of infallibility that persisted for millenia. His four-element theory virtually precluded the development of Chemistry and to question his mechanics was tantamount to heresy. In the same breath one can mention Claudius Ptolemaeus who flourished in Alexandria dming the second century CE. He produced the definitive description of the cosmos, with the Earth... 

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. 

Aristotle s four-element theory along with the formation of metals became the basis of early chemistry or alchemy as it was known then. A mixture of trickery and art, alchemy promised amazing things to those who held its power. 

Aristotle made little attempt to produce evidence to support his four-element theory. His later supporters pointed to the fact that, when a piece of wood is burned, fire issues from it, water oozes out of it, air is produced (in the form of smoke) and earth (ashes) remain behind. It had to be admitted that many other substances could not be analysed in this way, but in the absence of a better theory Aristotle s explanation of the material world remained in vogue until at least the sixteenth century. 

Aristotle s four-element theory was to exert a considerable influence on early laboratory chemistry, or alchemy (Chapter 2). The alchemists were also influenced by Aristotle s ideas on the formation of metals. He believed that metals and minerals were formed from exhalations. The two exhalations were a moist vaporous one, which was formed when the sun s rays fell on water, and a dry smoky one, which arose from the land. When these exhalations became imprisoned in the earth, they formed minerals or metals depending on which exhalation was... 

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. 

---