The Fontana History of Chemistry. William Brock J.

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.

      Most historians have seen three distinctive threads leading towards the development of Hellenistic alchemy: the empirical technology and Greek theories of matter already referred to, and mysticism – an unsatisfactory word that refers to a rag-bag of magical, religious and seemingly irrational and unscientific practices. Undoubtedly this third ingredient left its mark on the young science, and it in turn has left its mark on ‘mysticism’ right up until the twentieth century. In Hellenistic Egypt, as in Confucian China, there was a distinctive tendency to turn aside from observation and experiment and the things of this world to seek solace in mystical and religious revelations. It was the absorption of this element into alchemy that splintered its adherents into groups with different purposes and which later helped to designate alchemy as a pseudo-science.

      Recent studies have shown the considerable extent of pharmacological knowledge within the Arabic tradition. This tradition was to furnish the Latin west with large numbers of chemical substances and apparatus. It was clearly already well established in Greek alchemy, and it is to medicine that the historian must also look for another of alchemy’s foundation stones. For it was the Greek pharmacists who mixed, purified, heated and pulverized minerals and plants to make salves and tinctures. In Greek texts the word for a chemical reagent is, significantly, pharmakon.

      The modern conspectus is, therefore, that practical alchemy was the bastard child of medicine and pharmacy, as well as of dyeing and metallurgy. By applying Aristotelian, Neoplatonic, Gnostic and Stoic ideas to the practices of doctors and artisans, Greek alchemists reinterpreted practice as transmutation. This point is especially clear in a seventh-century AD text by Stephanos of Alexandria, ‘On the great and sacred art, or the making of gold’, in which he attacked goldsmiths for practising aurifiction. If such craftsmen had been properly educated in philosophy, he commented, they would know that gold could be made by means of an actual transformation.

      For one group of such-minded alchemical philosophers, astrology, magic and religious ritual grew at the expense of laboratory and workshop practice. Alchemical symbolism and allegory appealed strongly to the early Gnostics and Neoplatonists. The ‘death’ of metals, their ‘resurrection’ and ‘perfection’ as gold or purple dyes were symbolical of the death, resurrection and perfection of Christ and of what should, ideally, happen to the human soul. This esoteric alchemy is more the province of the psychologist and psychiatrist, as Jung claimed, or of the historian of religion and anthropology, than of the historian of chemistry. Nevertheless, as in the case of Isaac Newton, the historian of science must at all times be aware that, until the nineteenth century at least, most scientific activities were, fundamentally, religious ones. The historian of chemistry must not be surprised to find that even the most transparent of experimental texts may contain language that is allegorical and symbolical and which is capable of being read in a spiritual way.

      Exoteric alchemists continued their experimental labours, discovered much that was useful then and later, and suffered the indignities of bad reputation stemming from less noble confidence tricksters. Another group became interested in theories of matter and promoted discussion of ideas of particles, atoms or minima naturalis. Finally, the artisans and technologists continued with their recipes, uninterested in theoretical abstractions.

      The primitive notion that metals grew inside the earth had been supported by Aristotle in his treatise Meteorologica – the title referred to the physics of the earthly, as opposed to the celestial, sphere, and had nothing to do with weather forecasting. Less perfect metals, it was supposed, slowly grew to become more noble metals, like gold. Nature performed this cookery inside her womb over long periods of time – it was for this reason that, during the middle ages, mines were sometimes sealed so as to allow exhausted seams to recover, and for more metals to grow. If one interpreted the artisans’ aurifictions as aurifactions, then it appeared that they had successfully succeeded in repeating Nature’s process in the workshop in a short time. Perhaps further experimentation would bring to light other techniques for accelerating natural alchemical processes.

      Although Aristotle had never meant by ‘prime matter’ a tangible stuff that could be separated from substances, this was certainly how later chemists came to think of it. Similarly the tactile qualities became substantialized (substantial forms) and frequently identified with the aerial or liquid products of distillation, or pneuma.

      In gold-making, much use of analogy was made. Since there is a cycle of death and regrowth in Nature from the seed, its growth, decay and regeneration as seed once more, the alchemist can work by analogy. Lead is taken and ‘killed’ to remove its form and to produce the primary matter. The new substance is then grown on this compost. In the case of gold, its form is impressed by planting a seed of gold on the unformed matter. To grow this seed, warmth and moisture were requisite, and to perform the process, apparatus of various kinds – stills, furnaces, beakers and baths – was required, much of it already available from artisans or readily adapted from them.

      A secret technical vocabulary was developed in order to maintain a closed shop and to conceal knowledge from the uninitiated, a language that through its long history became more and more picturesque and fanciful. In Michael Maier’s Atalanta fugiens (1618), we read that ‘The grey wolf devours the King, after which it is buried on a pyre, consuming the wolf and restoring the King to life.’ All becomes clear when it is realized that this refers to an extraction of gold from its alloys by skimming off lesser metal sulphides formed from a reaction with antimony sulphide and the roasting of the resultant gold – antimony alloy until only gold remains. As Lawrence Principe has noted, this incomprehension on our part is surely little different from today’s mystification when the preparative organic chemist issues the order, ‘dehydrohalogenate vicinal dihalides with amide ion to provide alkynes’. In other words, although alchemists undeniably practised deliberate obfuscation, much of our incomprehension stems from its being in a foreign language, much of whose vocabulary has been lost. On the other hand, we must recognize that obscurity also suited the rulers and nobility of Europe, who patronized alchemists in the hope of solving their monetary problems.

ARABIC AND MEDIEVAL ALCHEMY

      Greeks alchemy spread geographically with Christianity and so passed to the Arabs, who were also party to the ideas and practices of Indian and Chinese technologists and alchemists. The story that alchemical texts were burned and alchemists expelled from Egypt by the decree of the Emperor Diocletian in 292 AD appears to be legendary. Alchemy does not seem to have reached the Latin west until