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Introduction - Creations of Fire .. World of Knowledge Magazine

Introduction

The history of chemistry is the story of human endeavor, an eccentric endeavor like human nature itself. Progress came in fits and starts, and came from all over the world.

It was necessary to establish some order because the span of this history is large (about 100 thousand years), and we have divided the text into three distinct sections in time, although they are major sections: The first section, chapters (71), covers the period from one hundred thousand years before the written era, until the eighteenth century, and in it we present the background of the chemical revolution. The second section (chapters 8-14) covers the period from the late eighteenth century until the First World War, and deals with the chemical revolution and what followed it. The third section (chapters 15-20) covers the period from the First World War until 1950, and presents the chemical revolution and its consequences, as well as signs of revolutions to come.

There have always been two tributaries to the current of chemistry: experiment and theory. But systematic experimental methods were not in regular use before the seventeenth century, and quantitative theories were not developed until the eighteenth century. It might be argued that modern chemistry did not begin as a science until the chemical revolution of the eighteenth century, but we say that the first experiments were carried out by craftsmen, while the first theories were proposed by philosophers. A revolution cannot be understood unless we know what it is that it is revolting against. So we will begin our account with the works of healers, artists, cloth weavers, and metal workers, and show how philosophers used their observations of craftsmen—whether explicit or not—to produce the first chemical theories. One of these theories—Aristotle’s theory of the four elements of fire, water, earth, and air—became the focus of experimental effort for nearly two thousand years.

There are two reasons for its longevity. The theory had intuitive appeal: it was assumed that the four elements were present in certain proportions in all substances. Indeed, when wood was burned, air (smoke rising, water (copying) dripping, soil (ash) forming, and fire (flaming) could be seen rising. The theory also held promise: if all matter was a mixture of elements, then it was possible to change the proportions of these elements in one substance to create another—that is, to perform a transmutation. The most interesting of the transmutations was the transmutation of base metals into gold—a transmutation pursued tirelessly from the first millennium BC to almost two millennia AD.

The efforts of the semioticians—who tested the theory of transmutation—particularly marked a ramification in the development of chemistry. The main trend was that the accumulation of chemical facts in succession by craftsmen would lead to the collapse of the theory. But it was an important ramification. The semioticians developed techniques that had applications in practical chemistry, and they influenced the public image of those who practiced experimental chemistry, which became associated with mystery, magic, mysticism, and deception. Even when the semioticians turned from the production of gold to more benevolent things such as the production of medicines (what we call the chemical reform of the sixteenth century), the image of chemistry took some time to change. In this way, this shift in direction—which coincided with the scientific revolution of the seventeenth century—brought a new kind of respect for chemical experimentation and inspired the serious transformations that produced the chemical revolution.

The chemical revolution, led by the French chemist Lavoisier, was a revolution against ambiguity and imprecision in thought and experimentation. When smoke mysteriously supported the idea that air was an element, careful thinkers wondered whether smoke was the pure element of air, and if so, why did air sometimes acquire different properties and different reactivity?

When the lightness of ash mysteriously supported the idea that something was leaving wood during heating, careful thinkers wondered why metals gained weight when heated? The chemical revolution had decisively and definitively dismissed magic as an explanation, authority as evidence, and unverifiable conjecture as chemical theory. The chemical revolution had decisively and definitively established the need for precise quantitative measurements in experimental analysis, the need for clear and pure language in analytical thinking, and the need for verifiable and verifiable experimental results to support chemical theory.

​​​​​​​The rejection of Aristotle's four elements led to the emergence of dozens more. Chemists used their new tools and ideas to discover new elements and the laws governing their reactions. Chemistry became a science, reactions could be controlled, chemical production became an industry, and chemists became professionals.

With all this progress, there remained a large gap in the theory: what forces hold the elements together? Electrochemical theories, in the nineteenth century, explained how opposite charges hold some elements together, but these theories failed - as did every other theory - to explain the existence of the simplest compound ever, molecular hydrogen, which consists of the union of two identical hydrogen atoms. Without an explanation for this, it was impossible for anyone to predict anything, except one thing: that it would require another revolution. This time, this revolution came much faster. With the new century, the twentieth century, came the quantum revolution.

Quantum theory, the basis of the quantum revolution, is the result of the combined efforts of physicists and chemists to understand radioactivity, the ability to react, and the structure of the atom. Rutherford, the founder of the planetary model of the atom, was a physicist by birth, but he won the Nobel Prize in Chemistry. Lewis, the chemist, had the insight, derived from extensive knowledge of chemical reactions, to propose the two-electron bond—on which chemists founded the quantum theory of the chemical bond. The explosion of experimental information and theoretical understanding began before the quantum revolution—but was accelerated by it—and led to the division of chemistry into branches. Biochemistry, organic chemistry, inorganic chemistry, analytical chemistry, and physical chemistry became independent fields, although their interaction was essential to the progress of each. The progress was made by chemists. We can now predict the properties of materials even before we make them, and we can assume what materials were present at the moment life itself was born. But what lies ahead in chemistry? It is difficult to predict. Aristotle would surely have been surprised by Lavoisier’s results, and Lavoisier would have been astonished by Lewis’s conclusions. And so we are sure to be astonished—and delighted—by the chemistry to come.