In the two millennia after Democritus first proposed that matter could be divided only until one reached a smallest defined particle, natural philosophers debated what the smallest unit of matter could be. With the flowering of the Scientific Revolution, the concept that atoms are the basic unit of matter was gradually established beyond dispute. And in the latter half of the century just past, several leading historians of science thought they had pinned down more or less exactly who knew what about atoms and when.

Schoolchildren in the 1950s and '60s were taught that each atom was a miniature solar system of sorts: a tiny, dense lump of protons and neutrons (the sun) ringed by a cloud of electrons orbiting in rapid circles (the planets). The number of negatively charged electrons exactly balanced the positive charge of the protons in the nucleus. We knew these electrons were in fixed orbits in a complex ladder based on each electron's energy level and the number of electrons orbiting the atom. And this knowledge was given currency on magazine covers and billboards and even television, depicting both good in the form of nuclear energy and evil in the form of bombs and fallout. These images reminded us that although atoms are unimaginably small, splitting an atom's nucleus released energy that made nuclear weapons not merely the most powerful bombs in history but something more, something difficult to grasp: real doomsday weapons.

While schoolchildren practiced hiding under their desks in "Duck and Cover" drills, historians of science were codifying a view of how and when atoms came to be seen as the basic unit of matter. Briefly, the idea that atoms are the smallest unit of any element was a minority opinion in Western science from its beginnings with Democritus all the way up through the late 1600s. Then—so the story went—the Scientific Revolution occurred. Reason reigned, superstition was superseded.

Readers who follow developments in physics and chemistry know that the scientific view of atoms today is much more complex than the mini-solar-system view popularized in the mid-20th century. It turns out that no one can determine both the position and the momentum of tiny subatomic particles, so the current view of electrons around the nucleus of an atom describes only a cloud of probable positions. The nucleus is far more complex than the spherical lump of positively charged and neutral particles pictured in textbooks just a few decades ago. Each proton and neutron is composed of smaller particles called quarks that exist for eons or fractions of seconds and have fractional charges and "colors" and spins and charm and other characteristics far more challenging to visualize and grasp than the old model.

So too, the popular image of the Scientific Revolution, representative of the mid-century scholarly consensus even if greatly simplified, has given way to messier narratives that reflect new understandings of the history of science. And nowhere is this change more apparent than in the revised estimate of alchemy among a growing number of contemporary scholars.

Alchemists, of course, figured in the familiar Enlightenment story as the last crazy magicians of the Middle Ages, charlatans scamming credulous creatures of the pre-modern world. In the 17th century, they were vanquished by the Scientific Revolution, their mummery discredited once and for all. But in Atoms and Alchemy: Chymistry and the Experimental Origins of the Scientific Revolution, William R. Newman tells a very different tale. Newman's intent with this book is to "give cause for reconsideration of the traditional 'grand narrative' of the Scientific Revolution. It is time to consider this topic anew rather than adding further lucubrations to the surveys and textbooks of our forebears." Aiming to rescue the beginnings of modern science from accumulated errors and misreadings, Newman clearly demonstrates that alchemists developed and refined laboratory practices that formed part of the foundation of what has become known as the Scientific Revolution. Far from springing up unbidden after a long and dreary epoch of rank superstition, the Scientific Revolution took root in the good soil of centuries of experimentation, much of it done by the alchemists.

This relatively slender book, in company with other recent scholarship that reconsiders what "everybody knows" about the history of science, promises to revolutionize the received understanding of the Scientific Revolution and the mechanical philosophy and experimentalism that characterized it. Newman is well aware that "alchemy" was an umbrella for a wide range of practices and pursuits, not all of which are pertinent to his argument. His dispute is with historians past and present who have denigrated alchemy tout court and who have failed to acknowledge its role in the development of modern science. They have told the story of the adoption of the mechanical philosophy as the recovery in the Latin West—supposedly in the 16th and 17th centuries—of the ancient views of atoms propounded by Democritus and Lucretius. In this account, these classical ideas were usefully modified by thinkers such as Pierre Gassendi and René Descartes, whom these historians have regarded as proto-physicists. To be sure, Robert Boyle is in their pantheon, but he has been characterized as bringing physical thinking to chemistry, or as having a split personality divided between a modern chemistry self and an alchemical self.

To refute this received opinion, Newman conducts a guided tour through the matter theories of half a dozen thinkers, showing in specific detail bloodlines from alchemy to modern chemistry. While Boyle and Thomas Aquinas will be familiar to most readers, the others—Geber, Thomas Erastus, Andreas Libavius, Julius Caesar Scaliger, and Daniel Sennert—will be new to readers not familiar with science in the middle of the past millennium. They are for the most part thinkers who were once important, but who have been left out of historical accounts because they simply don't fit the reigning narrative.

This tour demands of the reader a genuine curiosity about matter theories and the mental agility to imagine a time when chemical operations were not necessarily assumed to reveal something about the nature of matter. It requires understanding the meaning of scientific words in use today in rather different ways (much as C. S. Lewis illumined in Studies in Words). In an intriguing "Note on Terminology," Newman explains, for example, that "atom" did not necessarily mean absolute indivisibility as in classical theories; nor does "atom" imply indivisibility today. But early modern thinkers used a variety of related terms such as "corpuscle" and "molecule"—not surprisingly, without universally agreed upon definitions. Newman also points out that "mixture" and "compound" once meant almost the opposite of their meanings today.

Another potential surprise for the reader may be that there were, so to speak, at least two Aristotles. There was the familiar one of substance, forms, the four elements, and the four qualities. But there was also the less familiar one of minima, the smallest particles that exhibit the characteristics of a particular material. And in his Meteorologia, Aristotle presented mechanical sorts of explanations in which earth's exhalations condensed to form all the meteorological effects, or, if trapped in the earth, all the metals.

This tradition entered alchemical research at an early date—most prominently in the writings of Geber, the Arabic pseudonym for a 13th-century author called Paul of Taranto. Geber moreover brought experimental evidence taken from the metallurgical-alchemical tradition to bear on matter theory. In the fullness of time, this experimentalism became the gift of alchemy to the emergence of modern science.

Geber used a series of chemical reactions to argue against the Aristotelian theory of matter as explicated by Thomas Aquinas and in support of the sulfur-mercury theory of the composition of metals. In Aquinas' view, the generation of a new material presupposed the total corruption of the previous material, form and all, that is, resolution to the first simple elements (earth, air, fire, and water) or to prime matter itself. But Geber (who did not have mineral acids at his disposal) argued that metals could not be calcined (oxidized), their calces dissolved, sublimed, and finally reduced by fire if the metals had been corrupted all the way down to the four elements. If so, they might have come back, not as metals, but as almost anything! According to Geber, there must be some intermediate surviving principles that account for the metals; for him, these principles were sulfur and mercury.

Variants of this course of experiments, which Newman dubs "resolution to the prime state," appear in the alchemical literature right down through Robert Boyle. As if to emphasize that these reactions were really performed in laboratories and not simply in thought experiments, Newman provides color-photo reproductions of such a series as carried out in the laboratory of Cathrine Reck of the Indiana University Chemistry Department. And these are the only illustrations in the whole book: no curious alchemical symbols or quaint alchemical apparatus. The experiment pictured on the plates shows that solid metal could be dissolved in acid. The liquid acid could pass through filter paper, then the original metal could be restored. To pass through filter paper, the silver must have been resolved to very small particles indeed.

Newman and Lawrence Principe have identified Boyle's immediate predecessor in the use of this general course of experiments as Daniel Sennert, an early 17th-century German academic. Boyle did not acknowledge Sennert in this regard, perhaps because what Sennert tried to demonstrate through this chemistry was quite different from Boyle's use of it. As the reader will no doubt notice, there's a black box here: something persists through change, but what? According to Sennert that something was not any combination of the four elements but rather the invisible semina, which safely carried immaterial forms through change. For Boyle, the same reactions showed the semi-permanence of molecule-like corpuscles, which he at one point calls "primary clusters." These were not informed by forms but rather vice versa. Forms and qualities attributed to bodies really originated in the micro-texture of their particles, which Boyle aimed at demonstrating through other experiments. Newman likens the Sennert-Boyle difference of interpretation of experimental results to the debate between Joseph Priestley and Antoine Lavoisier over the dephlogisticated air/oxygen experiments. Priestley clung to the theory of phlogiston until his death. Lavoisier correctly deduced that the element he named oxygen was the key to combustion.

Newman doesn't mince words. Of one author's view of alchemy in the 17th century, Newman says, "he is badly mistaken … . [His] method consists largely of adding sociological explanations to the preexisting history of ideas." Newman chides the same author for missing things one would find with "closer reading" of source material. Of recent work on the Scientific Revolution Newman says: "In reality, the primary representatives of the most recent historiography have done little but proffer a new gloss on an old and outdated story." But Newman builds his case so carefully and persuasively that these combative words seem fully justified. By the final chapter the fine detail reveals a lovely picture of how the work of the alchemists, especially the mineral acid experiments pictured on the color plates in the center of the book, formed the foundation for modern atomism. Newman is especially vivid in re-creating the brilliant insights of Boyle, demonstrating that particles unimaginably small might be shown to exist without any of the modern instruments and apparatus we take for granted. This is a superb book with far-reaching implications.

Mary Ellen Bowden is senior research fellow at the Chemical Heritage Foundation (CHF) in Philadelphia.

Neil Gussman is communications manager at CHF.

Copyright © 2008 by the author or Christianity Today/Books & Culture magazine.
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