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Sidgwick’s Electronic Interpretation of Co-ordination Chemistry (#litres_trial_promo)
Australian Chemistry (#litres_trial_promo)
Australian and Japanese Chemistry (#litres_trial_promo)
Co-ordination Chemistry in Australia (#litres_trial_promo)
Nyholm’s Renaissance (#litres_trial_promo)
Conclusion (#litres_trial_promo)
16 At the Sign of the Hexagon (#litres_trial_promo)
Synthesis (#litres_trial_promo)
Industrial Chemistry (#litres_trial_promo)
Chemistry and the Environment (#litres_trial_promo)
EPILOGUE (#litres_trial_promo)
APPENDIX: HISTORY OF CHEMISTRY MUSEUMS AND COLLECTIONS (#litres_trial_promo)
NOTES (#litres_trial_promo)
BIBLIOGRAPHICAL ESSAY (#litres_trial_promo)
INDEX (#litres_trial_promo)
ACKNOWLEDGEMENTS (#litres_trial_promo)
ABOUT THE AUTHOR (#litres_trial_promo)
OTHER BOOKS BY (#litres_trial_promo)
COPYRIGHT (#litres_trial_promo)
ABOUT THE PUBLISHER (#litres_trial_promo)
‘Chemical Industry, Upheld by Pure Science Sustains the Production of Man’s Necessities’, frontispiece to A. Cressy Morrison, Man in A Chemical World: the service of chemical industry (London & New York: Scribner’s, 1937) Reproduced courtesy of Scribner’s, Collier Macmillan, New York
PREFACE TO THE FONTANA HISTORY OF SCIENCE (#ulink_64f61707-0a46-5c92-86ed-f055512217d6)
Academic study of the history of science has advanced dramatically, in depth and sophistication, during the last generation. More people than ever are taking courses in the history of science at all levels, from the specialized degree to the introductory survey; and, with science playing an ever more crucial part in our lives, its history commands an influential place in the media and in the public eye.
Over the past two decades particularly, scholars have developed major new interpretations of science’s history. The great bulk of such work, however, has been published in detailed research monographs and learned periodicals, and has remained hard of access, hard to interpret. Pressures of specialization have meant that few survey works have been written that have synthesized detailed research and brought out wider significance.
It is to rectify this situation that the Fontana History of Science has been set up. Each of these wide-ranging volumes examines the history, from its roots to the present, of a particular field of science. Targeted at students and the general educated reader, their aim is to communicate, in simple and direct language intelligible to non-specialists, well-digested and vivid accounts of scientific theory and practice as viewed by the best modern scholarship. The most eminent scholars in the discipline, academics well-known for their skills as communicators, have been commissioned.
The volumes in this series survey the field and offer powerful overviews. They are intended to be interpretative, though not primarily polemical. They do not pretend to a timeless, definitive quality or suppress differences of viewpoint, but are meant to be books of and for their time; their authors offer their own interpretations of contested issues as part of a wider, unified story and a coherent outlook.
Carefully avoiding a dreary recitation of facts, each volume develops a sufficient framework of basic information to ensure that the beginner finds his or her feet and to enable student readers to use such books as their prime course-book. They rely upon chronology as an organizing framework, while stressing the importance of themes, and avoiding the narrowness of anachronistic ‘tunnel history’. They incorporate the best up-to-the-minute research, but within a larger framework of analysis and without the need for a clutter of footnotes – though an attractive feature of the volumes is their substantial bibliographical essays. Authors have been given space to amplify their arguments and to make the personalities and problems come alive. Each volume is self-contained, though authors have collaborated with each other and a certain degree of cross-referencing is indicated. Each volume covers the whole chronological span of the science in question. The prime focus is upon Western science, but other scientific traditions are discussed where relevant.
This series, it is hoped, will become the key synthesis of the history of science for the next generation, interpreting the history of science for scientists, historians and the general public living in a uniquely science-oriented epoch.
ROY PORTER
Series Editor
BIBLIOGRAPHICAL NOTE (#ulink_cc3dd6c4-f83d-5161-8b8d-4d5a68feda82)
So as not to encumber the book with footnotes, I have employed the simple device of indicating the source of a quotation by a superscript number. These sources will be found in the relevant notes section (often briefly) and more details are given in the bibliographical essay, which not only provides an up-to-date guide to the published literature, but is also my acknowledgement to the hundreds of historians whose work has guided me in writing this book. For historical convenience, trivial rather than systematic (IUPAC) names are used for inorganic compounds, viz. ‘alum’ rather than ‘aluminium potassium sulphate-12-water’. In the case of organic compounds, systematic names are used only for more complex compounds.
INTRODUCTION (#ulink_3d11c803-03b2-583a-b3a1-9591eecb5245)
That all plants immediately and substantially stem from the element water alone I have learnt from the following experiment. I took an earthern vessel in which I placed two hundred pounds of earth dried in an oven, and watered with rain water. I planted in it the stem of a willow tree weighing five pounds. Five years later it had developed a tree weighing one hundred and sixty-nine pounds and about three ounces. Nothing but rain (or distilled water) had been added. The large vessel was placed in earth and covered by an iron lid with a tin-surface that was pierced with many holes. I have not weighed the leaves that came off in the four autumn seasons. Finally I dried the earth in the vessel again and found the same two hundred pounds of it diminished by about two ounces. Hence one hundred and sixty-four pounds of wood, bark and roots had come up from water alone.
(JOAN-BAPTISTA VAN HELMONT, 1648)
Helmont’s arresting experiment and conclusion capture the essence of the problem of chemical change. How and why do water and air ‘become’ the material of a tree – or, if that sounds too biochemical, how and why do hydrogen and oxygen become water? How does brute matter assume an ordered and often symmetrical solid form in the non-living world? Helmont’s experiment also raises the issue of the balance between qualitative and quantitative reasoning in the history of chemistry. Helmont’s observations are impeccably quantitative and yet, because he ignored the possible role of air in the reaction he was studying, and since he knew nothing of the hidden variables of nutrients dissolved in the water or of the role of the sun in providing the energy of photosynthesis, his reasoning was to prove qualitatively fallacious.
Chemistry is best defined as the science that deals with the properties and reactions of different kinds of matter. Historically, it arose from a constellation of interests: the empirically based technologies of early metallurgists, brewers, dyers, tanners, calciners and pharmacists; the speculative Greek philosophers’ concern whether brute matter was invariant or transformable; the alchemists’ real or symbolic attempts to achieve the transmutation of base metals into gold; and the iatrochemists’ interest in the chemistry and pathology of animal and human functions. Partly because of the sheer complexity of chemical phenomena, the absence of criteria and standards of purity, and uncertainty over the definition and identification of elements (the building blocks of the chemical tree), but above all because of the lack of a concept of the gaseous state of matter, chemistry remained a rambling, puzzling and chaotic area of natural philosophy until the middle of the eighteenth century. The development of gas chemistry after 1740 gave the subject fresh empirical and conceptual foundations, which permitted explanations of reactions in terms of atoms and elements to be given.
Using inorganic, or mineral, chemistry as its paradigm, nineteenth-century chemists created organic chemistry, from which emerged the fruitful ideas of valency and structure; while the advent of the periodic law in the 1870s finally provided chemists with a comprehensive classificatory system of elements and a logical, non-historically based method for teaching the subject. By the 1880s, physics and chemistry were drawing closer together in the sub-discipline of physical chemistry. Finally, the discovery of the electron in 1897 enabled twentieth-century chemists to solve the fundamental problems of chemical affinity and reactivity, and to address the issue of reaction mechanisms – to the profit of the better understanding of synthetic pathways and the expansion of the chemical and pharmaceutical industries.
Returning to Helmont’s tree, an arboreal image and metaphor can be usefully deployed. The historical roots of chemistry were many, but produced no sturdy growth until the eighteenth century. In this healthy state, branching into the sub-disciplines of inorganic, organic and physical chemistry occurred during the nineteenth century, with further, more complex branching in the twentieth century as instrumental techniques of analysis became ever more sophisticated and powerful. Growth was, however, dependent upon social and environmental conditions that either nurtured or withered particular theories and experimental techniques.
Although conceived as a work of synthesis for the 1990s (there has been no extensive one-volume history of chemistry published since that of Aaron Ihde in 1964), The Fontana History of Chemistry draws extensively upon some of the themes and personalities treated in my own research as well as upon the post-war work of other historians of chemistry. Gone are the days of Kopp and Partington, when a history of chemistry could be allowed to unfold slowly in four magisterial and detailed volumes. My volume is designed to be neither a complete nor a detailed narrative; nor is it a work of reference like James R. Partington’s History of Chemistry, to which I, like all historians of chemistry, remain profoundly indebted. I am particularly conscious, for example, of ignoring developments such as photography (that most chemical of nineteenth-century arts), spectroscopy, Russian chemistry, or the emergence of ideas concerning atomic structure. In some cases, as with the omission of any emphasis on the role of Avogadro’s hypothesis in the nineteenth-century determination of atomic and molecular weights, the lacuna is justified historiographically; in other cases, as with my muted references to the roles of rhetoric and language in chemistry, it was a decision not to introduce a contemporary historiographic fashion in a book largely dedicated to a readership of chemists and science students.
In yet other cases, choices of subject matter, and therefore of omission, have stemmed from the decision to structure chapters around seminal texts, their writers and the schools of chemists associated with them. This principle of organization has been freely borrowed from Derek Gjertsen’s The Classics of Science (New York: Lilian Barber, 1984) and a book edited by Jack Meadows, The History of Scientific Development (Oxford: Phaidon, 1987), with which I was associated. To use a metaphor from organic chemistry, the book is arranged around textual types, each title standing symbolically for a paradigm, a theoretical, instrumental or organizational change or development that seems significant to the historian of chemistry. I have tried to lay equal emphasis upon the practical (analytical) nature of past chemistry as much as on its theoretical content, and, although it would have taken a volume in itself to analyse the development of industrial chemistry, I have tried to provide the reader with an inkling of the application of chemistry. Wherever possible I have stressed the significance of chemistry for the development of other areas of science, and I have noted some of the false steps and blind alleys of past chemistry as much as the developments that still remain part of the scientific record. Echoing Ihde’s incisive treatment, The Fontana History of Chemistry also provides a generous treatment of twentieth-century chemistry – albeit within the constraints of my chosen themes and typologies. I have tried wherever possible to illustrate the international nature of the chemical enterprise since the seventeenth century.
Helmont’s tree leads us both backwards and forwards in time – forwards to when evidence accrued that air (and gases) did participate in chemical change, and backwards to the ancient traditions of elements and of transmutation that Helmut had inherited. The book opens with the roots of chemistry and the social, economic and religious environments that promoted it before the time of Helmont. In particular, the opening chapter examines early chemical technologies and their rationalization by Greek philosophers in theories of elements or, more iconoclastically, in terms of corpuscules and atoms. The tree enters here again, for one of the perennial proofs for the existence of elements and for their number was the destructive distillation of wood by fire – an important phenomenon empirically (for it was the model for distillation techniques generally) and cognitively because it was the basis of the concepts of analysis and synthesis. Chemistry was, and is, concerned with the analysis of substances into their elements and the synthesis of substances from their elements or immediate principles.
The possibility of manipulating elementary matter into substances of commercial or – at the extreme – of spiritually uplifting value, such as silver and gold or an elixir of life, led to alchemy. The latter’s origin, as well as its formal connections with chemistry, are complex and even contentious. However, our contemporary demand for science to have empirical validation, as well as our respect for the technological manipulation of Nature’s resources for the benefit of humankind, can be traced back to the philosophical spirit of enquiry that underpinned alchemical investigations. And it goes without saying that alchemy provided early chemistry with much of its apparatus and manipulative techniques, as well as the idea of a formal symbolic language for practitioners of the art.
Each of the sciences, no doubt, has its own difficulties and peculiarities when it comes to presenting its historical development to a diverse audience of professional historians, scientists, students and laypersons; but chemistry, like mathematics, possesses a particularly intimidating obstacle in its language and symbolism, which potentially obscures what are usually quite simple theoretical ideas and experimental techniques. As William Crookes noted in 1865 when reviewing a book on stuttering that had been inappropriately sent to Chemical News for review:
Chemists do not usually stutter. It would be very awkward if they did, seeing that they have at times to get out such words as methylethylamylophenylium.
However, if (as Peter Morris has noted) the historian avoids chemical detail and language, the scientific story become exigious and almost trivial. For this reason, while the first twelve chapters should present little difficulty to a sophisticated general reader, I have not hesitated to use technical language in the five chapters that are devoted to twentieth-century chemistry. Because this is a history, and not a textbook, of chemistry, I have not defined and explained symbols, equations and technical vocabulary. These chapters will present little difficulty to readers who have a secondary or high-school foundation in chemistry (and will have the privilege of being critical of my treatment). At the same time, it is to be hoped that there is sufficient of a human interest story in the intellectual and experimental worlds of Pauling, Ingold, Nyholm, Woodward and the other giants of twentieth-century chemistry, to propel the non-chemical reader towards the final pages.
The history of chemistry has served and continues to serve many purposes: didactic and pedagogic, professional and defensive, patriotic and nationalistic, liberalizing and humanizing. As I write, especially in America, where words like ‘chemical’, ‘synthetic’ and ‘additive’ have unfortunately become associated with the pollution, poisoning and disasters caused by humans, the history of chemistry has come to be seen by leaders of chemical industry and educators as a possible way of revaluing chemical currency: that is, of demonstrating not only the ways in which chemistry plays a fundamental role in nature and our understanding of cosmic processes, but also how it is essential to the economy of twentieth-century societies. In other words, the history of chemistry not only informs us about our great chemical heritage, but justifies the future of chemistry itself. Such a justification echoes the liberal and moving words of the first major historian of chemistry, Hermann Kopp
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The alchemists of past centuries tried hard to make the elixir of life … These efforts were in vain; it is not in our power to obtain the experiences and views of the future by prolonging our lives forward in this direction. However, it is possible and in a certain way to prolong our lives backwards, by acquiring the experiences of those who existed before us and by learning to know their views as if we were their contemporaries. The means for doing this is also an elixir of life.
It is in this spirit that The Fontana History of Chemistry has been written.
1 On the Nature of the Universe and the Hermetic Museum (#ulink_db813c83-ddce-5f41-904e-65eb73ac901a)
Maistryefull merveylous and Archimastrye Is the tincture of holy Alkimy;
A wonderful Science, secrete Philosophie,
A singular grace and gifte of th’Almightie:
Which never was found by labour of Mann,
But it by Teaching, or by Revalacion begann.
(THOMAS NORTON, The Ordinall of Alchemy, c. 1477)
In 1477, having succeeded after years of study in preparing both the Great Red Elixir and the Elixir of Life, only to have them stolen from him, Thomas Norton of Bristol composed the lively early English poem, The Ordinall of Alchemy. Here he expounded in an orderly fashion the procedures to be adopted in the alchemical process, just as an Ordinal lists chronologically the order of the Church’s liturgy for the year. Unfortunately, although the reader learns much of would-be alchemists’ mistakes, and of the ingredients and apparatus, of the subtle and gross works, and of the financial backing, workers and astrological signs needed to conduct the ‘Great Work’ successfully, the secret of transmutation remains tantalisingly obscure.
The historian Herbert Butterfield once dismissed historians of alchemy as ‘tinctured with the kind of lunacy they set out to describe’; for this reason, he thought, it was impossible to discover the actual state of things alchemical. Nineteenth-century chemists were less embarrassed by the subject. Justus von Liebig, for example, used the following notes to open his Giessen lecture course:
Distinction between today’s method of investigating nature from that in olden times. History of chemistry, especially alchemy …
Liebig’s presumption, still widespread, was that alchemy was the precursor of chemistry and that modern chemistry arose from a rather dubious, if colourful, past
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The most lively imagination is not capable of devising a thought which could have acted more powerfully and constantly on the minds and faculties of men, than that very idea of the Philosopher’s Stone. Without this idea, chemistry would not now stand in its present perfection …[for] in order to know that the Philosopher’s Stone did not really exist, it was indispensable that every substance accessible … should be observed and examined.
To most nineteenth-century chemists, and historians and novelists, alchemy had been a human aberration, and the task of the historian seemed to be to sift the wheat from the chaff and to discuss only those alchemical views (chiefly practical) that had contributed positively to the development of scientific chemistry. As one historiographer of the subject has put it
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[the historian] merely split open the fruit to get the seeds, which were for him the only things of value. In the fruit as a whole, its shape, colour, and smell, he had no interest.
But what was alchemy? The familiar response is that it involved the pursuit of the transmutation of base metals such as lead into gold. In practice, the aims of the alchemist were often a good deal broader, and it is only because we take a false perspective in seeing chemistry as arising from alchemy that we normally narrowly focus on to alchemy’s concern with the transformation of metals. However, as Carl Jung pointed out in his study Psychology and Alchemy, there are similarities between the emblems, symbols and drawings used in European alchemy and the dreams of ordinary twentieth-century people. One does not have to believe in psychoanalysis or Jungism to see that the most obvious explanation for this is that alchemical activities were often concerned with a spiritual quest by humankind to make sense of the universe. It follows that alchemy could have taken different forms in different cultures at different times.
At the beginning of the twentieth century, after the elderly French chemist, Marcellin Berthelot, had made available French translations of a number of Greek alchemical texts, an American chemist, Arthur J. Hopkins (1864–1939), showed how they could be interpreted as practical procedures involving dyeing and a series of colour changes. He was able to show how Greek alchemists, influenced by Greek philosophy and the practical knowledge of dyers, metallurgists and pharmacists, had followed out three distinctive transmutation procedures, which involved either tincturing metals or alloys with gold (as described in the Leiden and Stockholm papyri), or chemically manipulating a ‘prime matter’ mixture of lead, tin, copper and iron through a series of black, white, yellow and purple stages (which Hopkins was able to replicate in the laboratory), or, as in the surviving fragments of Mary the Jewess, using sublimating sulphur to colour lead and copper.
While Hopkins’ explanation of alchemical procedures has formed the basis of all subsequent historical work on early alchemical texts, and while Jung’s psychological interpretation has stimulated interest in alchemical language and symbolism, it was the work of the historian of religion, Mircea Eliade (1907–86), who, following studies of contemporary metallurgical practices of primitive peoples in the 1920s, firmly placed alchemy in the context of anthropology and myth in Forgerons et Alchimistes (1956).
These three twentieth-century interpretations of alchemy, dyeing, psychological individuation and anthropology, together with the historical investigation of Chinese alchemy being undertaken by Joseph Needham and Nathan Sivin in the 1960s, stimulated the late Harry Sheppard to devise a broad definition of the nature of alchemy
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Alchemy is a cosmic art by which parts of that cosmos – the mineral and animal parts – can be liberated from their temporal existence and attain states of perfection, gold in the case of minerals, and for humans, longevity, immortality, and finally redemption. Such transformations can be brought about on the one hand, by the use of a material substance such as ‘the philosopher’s stone’ or elixir, or, on the other hand, by revelatory knowledge or psychological enlightenment.
The merit of such a general definition is not only that it makes it clear that there were two kinds of alchemical activity, the exoteric or material and the esoteric or spiritual, which could be pursued separately or together, but that time was a significant element in alchemy’s practices and rituals. Both material and spiritual perfection take time to achieve or acquire, albeit the alchemist might discover methods whereby these temporal processes could be speeded up. As Ben Jonson’s Subtle says in The Alchemist, ‘The same we say of Lead and other Metals, which would be Gold, if they had the time.’ And in a final sense, the definition implies that, for the alchemist, the attainment of the goals of material, and/or spiritual, perfection will mean a release from time itself: materially through riches and the attainment of independence from worldly economic cares, and spiritually by the achievement of immortality.
The definition also helps us to understand the relationship between the alchemies of different cultures. Although some historians have looked for a singular, unique origin for alchemy, which then diffused geographically into other cultures, most historians now accept that alchemy arose in various (perhaps all?) early cultures. For example, all cultures that developed a metallurgy, whether in Siberia, Indonesia or Africa, appear to have developed mythologies that explained the presence of metals within the earth in terms of their generation and growth. Like embryos, metals grew in the womb of mother Nature. The work of the early metallurgical artisan had an obstetrical character, being accompanied by rituals that may well have had their parallel in those that accompanied childbirth. Such a model of universal origin need not rule out later linkages and influences. The idea of the elixir of life, for example, which is found prominently in Indian and Chinese alchemy, but not in Greek alchemy, was probably diffused to fourteenth-century Europe through Arabic alchemy. The biochemist and Sinologist, Joseph Needham, has called the belief and practice of using botanical, zoological, mineralogical and chemical knowledge to prepare drugs or elixirs ‘macrobiotics’, and has found considerable evidence that the Chinese were able to extract steroid preparations from urine.
Alongside macrobiotics, Needham has identified two other operational concepts found in alchemical practice throughout the world, aurifiction and aurifaction. Aurifiction, or gold-faking, which is the imitation of gold or other precious materials – whether as deliberate deception or not depending upon the circumstances (compare modern synthetic products) – is associated with technicians and artisans. Aurifaction, or gold-making, is ‘the belief that it is possible to make gold (or “a gold”, or an artificial “gold”) indistinguishable from or as good as (if not better than) natural gold, from other different substances’. This, Needham suggests, tended to be the conviction of natural philosophers rather than artisans. The former, coming from a different social class than the aurifictors, either knew nothing of the assaying tests for gold, or jewellery, or rejected their validity.
CHINESE ALCHEMY (#ulink_fb79a08c-55ff-53db-90e6-36fb7720f750)
Aurifactional alchemical ideas and practices were prevalent as early as the fourth century BC in China and were greatly influenced by the Taoist religion and philosophy devised by Lao Tzu (c. 600 BC) and embodied in his Tao Te Ching (The Way of Life). Like the later Stoics, Taoism conceived the universe in terms of opposites: the male, positive, hot and light principle, ‘Yang’; and the female, negative, cool and dark principle, ‘Yin’. The struggle between these two forces generated the five elements, water, fire, earth, wood and metal, from which all things were made:
Unlike later Greco-Egyptian alchemy, however, the Chinese were far less concerned with preparing gold from inferior metals than in preparing ‘elixirs’ that would bring the human body into a state of perfection and harmony with the universe so that immortality was achieved. In Taoist theory this required the adjustment of the proportions of Yin and Yang in the body. This could be achieved practically by preparing elixirs from substances rich in Yang, such as red-blooded cinnabar (mercuric sulphide), gold and its salts, or jade. This doctrine led to careful empirical studies of chemical reactions, from which followed such useful discoveries as gunpowder – a reaction between Yin-rich saltpetre and Yang-rich sulphur – fermentation industries and medicines that, according to Needham, must have been rich in sexual hormones. As in western alchemy, Taoist alchemy soon became surrounded by ritual and was more of an esoteric discipline than a practical laboratory art.
Belief in the transformation of blood-like cinnabar into gold dates from 133 BC when Li Shao-chun appealed to the Emperor Wu Ti to support his investigations:
Summon spirits and you will be able to change cinnabar powder into yellow gold. With this yellow gold you may make vessels to eat and drink out of. You will increase your span of life, you will be able to see the hsien of the P’eng-lai [home of the Immortals] that is in the midst of the sea. Then you may perform the sacrifices fang and shang and escape death.
From then on, many Chinese texts referred to the consumption of potable gold. This wai tan form of alchemy, which was systematized by Ko Hung in the fourth century AD, was not, however, the only form of Chinese alchemy.
The Chinese also developed nai tan, or physiological, alchemy, in which longevity and immortality were sought not from the drinking of an external elixir, but from an ‘inner elixir’ provided by the human body itself. In principle, this was obtained from the adept’s own body by physiological techniques involving respiratory, gymnastic and sexual exercises. With the ever-increasing evidence of poisoning from wai tan alchemy, nai tan became popular from the sixth century AD, causing a diminution of laboratory practice. On the other hand, nai tan seems to have encouraged experimentation with body fluids such as urine, whose ritualistic use may have led to the Chinese isolation of sex hormones.
As Needham has observed, medicine and alchemy were always intimately connected in Chinese alchemy, a connection that is also found in Arabic alchemy. Since Greek alchemy laid far more stress on metallurgical practices – though the preparation of pharmaceutical remedies was also important – it seems highly probable that Arabic writers and experimentalists were ‘deeply influenced by Chinese ideas and discoveries’.
There is some evidence that the Chinese knew how to prepare dilute nitric acid. Whether this was prepared from saltpetre – a salt that is formed naturally in midden heaps – or whether saltpetre followed the discovery of nitric acid’s ability to dissolve other substances, is not known. Scholars have speculated that gunpowder – a mixture of saltpetre, charcoal and sulphur – was first discovered during attempts to prepare an elixir of immortality. At first used in fireworks, gunpowder was adapted for military use in the tenth century. Its formula had spread to Islamic Asia by the thirteenth century and was to stun the Europeans the following century. Gunpowder and fireworks were probably the two most important chemical contributions of Chinese alchemy, and vividly display the power of chemistry to do harm and good.
As in the Latin west, most of later Chinese alchemy was little more than chicanery, and most of the stories of alchemists’ misdeeds that are found in western literature have their literary parallels in China. Although the Jesuit missions, which arrived in China in 1582, brought with them information on western astronomy and natural philosophy, it was not until 1855 that western chemical ideas and practices were published in Chinese. A major change began in 1865 when the Kiangnan arsenal was established in Shanghai to manufacture western machinery. Within this arsenal a school of foreign languages was set up. Among the European translators was John Fryer (1839–1928), who devoted his life to translating English science texts into Chinese and to editing a popular science magazine, Ko Chih Hui Phien (Chinese Scientific and Industrial Magazine).
GREEK ALCHEMY (#ulink_81ad973a-1e20-531b-8b4e-a2d767b2d437)
Although it is possible to argue that modern chemistry did not emerge until the eighteenth century, it has to be admitted that applied, or technical, chemistry is timeless and has prehistoric roots. There is conclusive evidence that copper was smelted in the Chalcolithic and early Bronze Ages (2200 to 700 BC) in Britain and Europe. Archaeologists recognize the existence of cultures that studied, and utilized and exploited, chemical phenomena. Once fire was controlled, there followed inevitably cookery (gastronomy, according to one writer, was the first science), the metallurgical arts, and the making of pottery, paints and perfumes. There is good evidence for the practice of these chemical arts in the writings of the Egyptian and Babylonian civilizations. The seven basic metals gave their names to the days of the week. Gold, silver, iron, mercury, tin, copper and lead were all well known to ancient peoples because they either occur naturally in the free state or can easily be isolated from minerals that contain them. For the same reason, sulphur (brimstone) and carbon (charcoal) were widely known and used, as were the pigments, orpiment and stibnite (sulphides of arsenic and antimony), salt and alum (potassium aluminium sulphate), which was used as a mordant for vegetable dyes and as an astringent.
The methods of these early technologists were, of course, handed down orally and by example. Our historical records begin only about 3000 BC. With the aid of techniques derived ultimately from the kitchen, these artisans extracted medicines, perfumes and metals from plants, animals and minerals. Their goldsmiths constructed wonderful pieces of jewellery and their metallurgists worked familiarly with the common metals and their alloys, associating them freely with the planets. Jewellers were particularly interested in the different coloured effects of the various alloys that metallurgists prepared and in the staining of metallic surfaces by salts and dyes, or the staining of stones and minerals that imitated the colours of precious minerals. In fact, throughout the east we find an emphasis upon colour, and the establishment of what Needham describes as the industry of aurifiction. Clearly there existed a professional class of artisans, metallurgists and jewellers who specifically designed and made imitation jewellery from mock silver, gold or artificial stones. The Syrians and Egyptians appear to have developed a particular talent for this work, and written examples of their formulae or recipes have survived in handbooks that were compiled centuries later in about 200 BC. For example, to prepare a cheaper form of ‘asem’, an alloy of gold and silver:
Take soft tin in small pieces, purified four times; take four parts of it and three parts of pure white copper and one part of asem. Melt, and after casting, clean several times and make with it whatever you wish to. It will be asem of the first quality, which will deceive even the artisans.
Or, in the equivalent of nineteenth-century electroplating, to make a copper ring appear golden so that ‘neither the feel nor rubbing it on the touchstone will discover it’:
Grind gold and lead to a dust as fine as flour; two parts of lead for one of gold, mix them and incorporate them with gum, coat the ring with this mixture and heat. This is repeated several times until the object has taken the colour. It is difficult to discover because the rubbing power gives the mark of an object of gold and the heat [test] consumes the lead and not the gold.
In one sense this aurifictional technology can be described as simple empiricism. To say that, however, does not mean that its practitioners were devoid of ideas about the processes they worked, or that they had no model to underpin their understanding of what was happening. Given that these technologies were evidently closely bound up with magic, ritual and trade secrecy, this was equivalent to a theoretical underpinning. Although these artisans may not have had any sophisticated chemical theory to explain or guide their practices, that experience was undoubtedly bound up with ritualistic beliefs concerning the objects that were handled. We need only notice the more than obvious connection of the names of metals with the planets, and
TABLE 1.1 The ancient associations of metals and the heavens.
from them the names of the week (table 1.1), as well as beliefs that metals grew inside the earth, to conclude that myth and analogy played the equivalent role of chemical theory in these technologies. Moreover, it seems highly likely from later written records that metallurgists believed that, while metals grew normally at a slow pace within the earth, they could accelerate this process within the smithy, albeit an appropriate planetary god or goddess had to be propitiated by ritual purification for the rape of mother earth. It was this element of ritual, albeit in a Christianized form in the Latin west and a Taoist form in China, that was handed on to the science of alchemy.
For a science alchemy was. Theory controlled and exploited the empirical. Alchemy became a science when the masses of technical lore connected with dyeing and metallurgy became confronted by and amalgamated with Greek theories of matter and change. Greek philosophers with their strong sense of rationality and logic contributed a theory of matter that was able to order, classify and explain technological practice. The pre-Socratic philosophers of the sixth century BC had conjectured that the everyday substances of this material world were generated from some one primary matter. Both Plato (c 427–c 347 BC) and Aristotle (384–322 BC), teaching in the fourth century BC, had also written of this prime matter as a featureless, quality-less stuff, rather like potter’s clay, onto which the various qualities and properties of hotness, coldness, dryness and moistness could be impressed to form the four elements that Empedocles (d. c. 430 BC) had postulated in the fifth century BC. This quartet of elementary substances, in their turn, mixed together in various proportions to generate perceptible substances. Conversely, material substances could, at least in principle and often in practice, be analysed into these four components:
Although Aristotle seems not to have articulated a theory of cohesion, we may assume that the four elements were ‘bound together’ by the moist quality. Expressed in rectangular diagrammatic form, which became the basis for later geometrical talismans and symbols, each adjacent element can be seen to possess a common quality; hence all four of the elements are, in principle, interconvertible. Thus, by changing the form or forms (transformation) of bodies, Nature transmutes the underlying basic, or primary, matter into different substances. Despite pertinent criticisms by Theophrastus (371–286 BC), Aristotle’s pupil and successor at the Lyceum, that fire was different from other elements in being able to generate itself and in needing other matter to sustain it, the theory of the four elements was to remain the fundamental basis of theoretical chemistry until the eighteenth century.
For Aristotle there was a fundamental distinction between the physics of the heavens, which were eternal, perfect, unchanging and endowed with natural circular motion, and the sublunar sphere of the earth, which was subject to change and decay and where movement was either upwards or downwards from the centre of the universe. This sublunar region was composed from Empedocles’ four elements. Aristotle had rejected the atomic theory introduced in the fifth century BC by Democritus. The claim that the apparent differences between substances arose from differences in the shapes and sizes of uncuttable, homogeneous particles, while ingenious, seemed to Aristotle pure invention, whereas the four elements lay close to human sensory experience of solids and liquids and of wind and fire, or of hot and cold, wet and dry objects. How could atomism account for the wide variety of shapes and forms found in minerals in the absence of a formal cause? Moreover, to Aristotle, the postulation of a void meant that there was no explanation for motion, and without motion there could be no change. Atomism also failed to distinguish between physical and mathematical division – a problem that was overcome after Aristotle’s death by Epicurus (341–270 BC), who allowed that, although atoms were the unsplittable physical minima of matter, because an atom had definite size, it could be said to contain mathematically indivisible parts. Epicurus also explained the compounding of atoms together as they fell with equal speeds through the void as due to sudden ‘swerves’ or deviations. These unpredictable swerves are a reminder that atomism, as popularized in Epicurean philosophy, had more to do with the establishment of a moral and ethical philosophy than as an interpretation of the physics and chemistry of change. Swerving atoms allowed for human free will. Atomism for the Epicureans, as well as for its great poetic expositor, the Roman Lucretius in De rerum natura (c. 55 BC), was a way of ensuring human happiness by the eradication of anxieties and fears engendered by religions, superstitions and ignorance. Ironically, in the sixteenth century, atomism began to be used as a way of eliminating the superstitions and ignorance of Aristotelianism.
The other great post-Aristotelian system of philosophy, Stoicism, because it adopted and adapted considerable parts of Aristotelianism, was more influential. Founded by the Athenian, Zeno (342–270 BC), during the fourth century BC and refined and developed up to the time of Seneca in the first century AD, Stoicism retained Aristotle’s plenistic physics and argued for the indefinite divisibility of matter. Stoics laid stress on the analogy between macrocosm and microcosm, the heavens and the earth, and distinguished between inert matter and a more active form, the latter being called the pneuma, or vital spirit. Pneuma pervaded the whole cosmos and brought about generation as well as decay. Ordinary substances, as Empedocles and Aristotle had taught, were composed from the four elements, albeit hot and dry, fire and air were more active than passive wet and cold, water and earth. From this it was but a short step to interpreting air and fire as forms of pneuma, and pneuma as the glue or force that bound passive earth and water into cohesive substances. The concept was to have a profound effect on the interpretation of distillation.
Chemical compounds (an anachronism, of course) were mixtures of these four elements in varying proportions – albeit Aristotle’s and the Stoics’ views were rather more sophisticated than this bald statement suggests. The central theorem of alchemy, transmutation, could be seen in one of two ways, either as what we would call chemical change caused by the different proportions of elements and their rearrangement, or as a real transmutation in which the qualities of the elements are transformed. Alchemy allowed far more ‘transmutations’ than later chemistry was to allow, for it permitted the transmutation of lead or other common metals into gold or some other precious metal. A real transmutation of lead and gold was to be achieved by stripping lead of its qualities and replanting the basic matter that was left with the qualities and attributes of gold. Since lead was dense, soft and grey, while gold was dense, soft and yellow, only a change of colour seemed significant. However, although alchemy is usually taken to be the science of restricted metallic transmutations, it is worth emphasizing that it was really concerned with all chemical changes. In that very general sense, alchemy was the basis of chemistry.
One of the most important geographical areas for the creation of alchemy was Egypt during the Hellenistic period from about 300 BC to the first century AD. Egypt was then a melting pot for Greek philosophy, oriental and Christian religions, astrology, magic, Hermeticism and Gnosticism, as well as trade and technology. Hermeticism, which took its title from Hermes, the Greek form of the Egyptian deity, Thoth, the father of all book learning, was a blend of Egyptian religion, Babylonian astrology, Platonism and Stoicism. Its vast literature, the Hermetic books, supposedly written by Hermes Trismegistus, was probably compiled in Egypt during the second century BC. Gnosticism, on the other hand, was an ancient Babylonian religious movement, which stressed the dualism between light and darkness, good and evil. Gnosis was knowledge obtained only through inner illumination, and not through reason or faith. Humankind was assured of redemption only from this inner enlightenment. Gnosticism both competed with early Christianity and influenced the writing of the Gospels. As its texts show, however, Gnosticism was as much influenced by contemporary alchemy as it influenced alchemical language. For example, in the Gnostic creation story, chemical expressions referring to sublimation and distillation are found, as in the phrase ‘the light and the heavy, those which rise to the top and those which sink to the bottom’. The most important of the Gnostics, Theodotos, who lived in the second century AD, used metaphors of refining, filtering, purifying and mixing, which some historians think he may have drawn from the alchemical school of Mary the Jewess. When Gnostic language is met in alchemical texts of the period, such as the Dialogue of Kleopatra and the Philosophers, however, it is difficult to know whether the author is referring to the death and revivification of metals or to the death and regeneration of the human soul. Exoteric alchemy had become inextricably bound with esoteric alchemy.
