Epilogue

The Epilogue concludes with a brief look at some of the exciting, and more positive, aspects of chemistry since the 1960s: the use of computers to study perfect three-dimensional structural models and design new molecules on the screen; combinatorial chemistry; retrosynthesis; the discoveries of the carbon allotropes fullerene and graphene; and nanotechnology. In an age of cross-disciplinary, transdisciplinary science and technology several historians, sociologists, and philosophers of science have queried whether the concept of distinct scientific disciplines like chemistry, physics, and biology serves a purpose any longer. Has chemistry become a service science, or has chemistry taken over these other disciplines?

6. Synthesis

‘Synthesis’ considers how the shape and scale of chemistry has been transformed since the start of the 20th century. A series of world wars; a shift from coal to oil as the feedstock for the chemical industry; the introduction of physical instrumentation, quantum mechanics, and electronic theories; the organization of academia and industry to create Big Science as opposed to the more individualized research of previous centuries; a shift from European dominance of the subject to the US and then Russia, Japan, and China; and more women joining the profession have all been important. Underlying these changes was the theme of synthesis of natural chemicals and the creation of artificial materials.

1. On the nature of stuff

‘On the nature of stuff’ shows that the ability to control fire and temperature led to the first chemical technologies: the production of pottery from fired clays and tempers, metals, glass, and bitumen products. It goes on to describe the early speculation of matter by Greek philosophers, such as Empedocles and Aristotle, before discussing the history of alchemy in Europe and the Muslim empire. The same synonyms were often used for different substances resulting in confusion and secrecy. It was Isaac Newton (1642–1727) who compiled an index chemicus in an attempt to make sense of alchemical language and allegory. The demise of alchemy, the move from chymistry to chemistry, and the rise of modern chemistry are also considered.

3. Gases and atoms

Until the mid-18th century, chemists had no understanding of the role of air in chemical changes. The Chemical Revolution was not merely conceptual, but also instrumental in that it involved the practical ability to manipulate, weigh, and measure gases using accurate balances, glass apparatus, and eudiometers. The chemist who transformed our views of elements, composition, and reorganized the way that chemists communicated was the French civil servant Antoine Lavoisier (1743–94). ‘Gases and atoms’ outlines Lavoisier’s work on chemistry nomenclature along with the key chemical discoveries by Joseph Black, Henry Cavendish, and Joseph Priestley. John Dalton’s atomic theory and the problem of ascertaining the molecular structure of water are also discussed.

Introduction

Chemistry has always been the science of matter and a technology for creating new things through metamorphosis and transmutation. In 1800 the elements and compounds known to chemistry numbered only a few hundred; today, they number more than seventy-one million. Few of these substances actually exist in nature; rather, they have been isolated, prepared, and studied by chemists in particular times and places by an evolving repertoire of laboratory practices and theoretical insights, and recorded in publications in various languages. This Introduction outlines the remit of this VSI to describe how explanations were found for the metamorphosis of materials and new transmutations were discovered, studied, and exploited.

5. Reactivity

By the mid-19th century many different kinds of chemical change had been recognized and systematized in textbooks. It became the task of physical chemists to explain these different transformations in terms of exchanges between atoms and molecules powered by energy changes and the shifts in equilibrium that underlay all reactivity. Physical chemists found ways of expressing chemical change in mathematical terms and so brought generalization and systematization to chemical practice. ‘Reactivity’ considers the conditions for chemical equilibria and the mechanisms involved in chemical reactions by discussing concepts such as thermodynamics, periodicity, spectroscopy, ideal gases, Boyle’s law, electrolysis, ionic theory, kinetics, and inert gases.

2. The analysis of stuff

The fundamental problem in chemistry is transmutation. How can two homogeneous stuffs with very different properties merge to form another homogeneous material whose properties are different from the reactants? ‘The analysis of stuff’ outlines the history of chemical analysis beginning in the early 16th century with Paracelsus, a deeply religious practising doctor who began to work with chemical remedies rather than those based on plants. The iatrochemistry movement promoted by Paracelsians meant that chemistry became part of the European medical curriculum. Other key characters in the chemical revolution are also discussed—Joan Baptista van Helmont, Daniel Sennert, and Robert Boyle—along with the documentation of elements by Antoine Lavoisier and Isaac Newton.

4. Types and hexagons

‘Types and hexagons’ introduces some of the key characters involved in making important contributions to the field of chemistry: Antoine Fourcroy, who created the divisions of inorganic and organic chemistry; Friedrich Kekulé, who defined organic chemistry as the chemistry of carbon compounds and proposed benzene’s hexagonal structure; Justus Liebig, who applied chemistry to agriculture, physiology, medicine, nutrition, and industry; Berzelius, who introduced the term isomerism and the electrochemical system of classification; French chemists Charles Gerhardt and August Laurent; Edward Frankland, who proposed valency; Alfred Werner and his coordination theory of molecular structure; and Alexander Williamson, who had a pivotal role in the development of 19th-century chemistry.