There has always been a need to analyze things and substances down to component parts in order to explain material characteristics in terms of combinations of some simpler, basic pieces. Near the beginning of civili­zation, as writing, fixed agriculture, and manufacturing became human activities, a common theory of element analysis seemed to appear in sev­eral places. This practical, working theory was that everything is com­posed of various combinations of four elements: earth, air, fire, and water. Although this concept now seems quaint, in ancient times it made a cer­tain logical sense. Steam, for example, was obviously composed of air, containing a measure of water, giving it wetness, plus fire, giving it heat. Bricks were made of earth, with the water removed, wine was water with a bit of earth and fire mixed in, and something as complex as wood was mainly earth, with some water, air, and fire locked in, to be extracted when the wood was burned. Burn the wood, and the fire would escape, the water and air would evaporate away, and one is left with only a pile of black earth or ashes.

With this rough but practical working theory, technology and science managed to progress very slowly for thousands of years. There were some other theories, often showing brilliant insight in a world lacking a base of scientific knowledge. The first written mention of a true atomic analysis of matter dates to around 550 b. c.e. in India, where elaborate theories were developed by the Nyaya and Vaisheshika schools, describing how elemen­tary particles combine, first in pairs, then in trios of pairs, to produce more complex substances. The first references to an atomic structure in the West appeared 100 years later. A teacher named Leucippus (ca. fifth century b. c.e.) in Greece thought of a scheme in which all matter was composed of smaller pieces, with the smallest pieces being incapable of being broken into smaller pieces. His views were recorded and system­atized by a student, Democritus (ca. 460 b. c.e.-370 b. c.e.), around 430 b. c.e., and in this work the word atomos was first used, meaning “uncutta-

ble.” The Greek word was later shortened to atom. These were fine theories and were pointed in the right direction, but they were of no practical use and were considered philosophy. These theoretical atoms were too small to be seen, and there was no experimental confirmation that any of these ideas had a basis in reality.

Through the turn of the millennium, in 1000 C. E., the practice of indus­trial chemistry, in which useful compounds such as soap were formed by mixing two or more substances, increased in importance, and the lack of utility in the ancient earth-air-fire-water model of matter began to become evident. Gold, for example, was apparently earth because it was a solid, but the difference between gold and copper was difficult to define or explain. There was no systematic method of analysis available and no way to quantify the subtle differences among metals, liquids, or gases. Any analysis was simply an opinion, and the art of chemistry had to turn to unproductive, mystic explanations for compounds and alloys.

In 1661, Robert Boyle (1627-91), a well-educated, Irish gentleman of independent means, having attended Eton College in England, pub­lished a book with the verbose title THE SCEPTICAL CHYMIST: OR CHYMICO-PHYSICAL Doubts &

Paradoxes, Touching the SPAGYR — ISTS PRINCIPLES Commonly calVd HYPOSTATICAL, As they are wont to be Propos’d and Defended by the Generality of ALCHYMISTS. This book broke new ground in that Boyle finally called the four-element sys­tem to task and harshly criticized the more advanced work of the Spagyr — ists, who contended that solid matter was composed of various combina­tions of salt, sulfur, and mercury. He went further to advance the theory, once again, that matter is composed of elements, which are undecom- atoms, and he described the process of chemical analysis and

the fundamental differences between compounds and mixtures of com­pounds. Boyle s other work studying the properties of gases is considered an important beginning to formal science, but his chemistry book was a monumental start in the understanding of atomic structures.

After Boyle, formal science gathered speed, and the ancient concepts of matter were buried. In 1789, Antoine-Laurent Lavoisier (1743-94), a French nobleman, chemist, and economist, first used the term elements to describe oxygen and hydrogen, claiming that these two gases could not be broken chemically into more elementary components. He compiled the first table of elements and went on to introduce the metric system of measurements. He also advanced physics by formulating the law of con­servation of mass, by which matter can neither be created from nothing nor destroyed but only be changed in form.

In 1808, John Dalton (1766-1844), an English chemist, meteorologist, and physicist, published the first volume of his New System of Chemical

Philosophy, in which he stated the following five main points of his atomic theory:

П Elements are composed of indivisible particles called atoms.

П All atoms of a given element are identical.

П The atoms of a given element are different from those of any other element.

П Atoms of one element may combine with the atoms of other ele­ments to form compounds.

П Atoms may not be broken into smaller particles, destroyed, or created from combinations of smaller particles by chemical action.

Although these simple rules may now seem obvious, Dalton’s work solidi­fied Boyle’s findings and set the course for chemistry and physics for the next 200 years.

By the late 19th century, the existence and the importance of the atom were firmly established. The next increment of knowledge would be large and unexpected, when it was discovered that the undecomposable, indi­visible atoms were falling apart.