For a report of the 75th Anniversary Meeting, The History of the History of Chemistry (Autumn 2010) click here.
Journée d’étude sur la chimie et l’alchimie au XVIIe siècle
(Colloquium on seventeenth-century chemistry and alchemy)
9 June 2010, Lille
On Wednesday 9 June, The Society for the History of Alchemy and Chemistry held a meeting at Université de Lille 3, Villeneuve d’Ascq, Lille. The event marked the second leg of a two-part, collaborative colloquium organised by SHAC and UMR ‘Savoirs, Textes, Langage’ (CNRS, universités de Lille 3 et de Lille 1). At the first meeting, held in June 2009, scholars from Lille visited London to present their work on ‘Chymistry and Mechanism in the Seventeenth and Eighteenth Centuries’. In June 2010, five British and American scholars visited Lille to give papers on ‘Seventeenth-Century Chemistry and Alchemy’.
The first paper was given by Jennifer Rampling (University of Cambridge/Scaliger Instituut, Universiteit Leiden), entitled ‘“Which masters call sericon”: the evolution of an alchemical practice, 1471–1678’. Dr Rampling traced the history of a mysterious alchemical substance, ‘sericon’, in order to examine one problem faced by historians of alchemy – the difficulty of isolating and tracking changes in alchemical ideas, practices and nomenclature over time. Sericon is named as the main ingredient in several fifteenth-century English recipes for the ‘vegetable stone’, an alchemical product capable of preserving and restoring health, and (following further procedures) able to transmute metals. However, both the identity of sericon, and the alchemical practice it represented, were reinterpreted between the fifteenth and seventeenth centuries. In the Medulla alchimiae(1476) of George Ripley, and other works of the same period, sericon denotes red lead, which is dissolved in wine vinegar. Throughout the sixteenth century, ‘sericonian’ alchemy continued to be read as a process using lead and vinegar. However, competing interpretations also evolved, as early modern readers, struggling with the precise nature of ‘sericon’, tried other readings: verdigris, minium of copper, or – most commonly – antimony.
The shift is apparent in two interpretations of the same alchemical poem, the Vision of George Ripley. The first, made in 1577 by Samuel Norton, gives a standard sericonian reading using red lead and vinegar. The second, made in the 1650s by the Bemuda-born alchemist George Starkey, interprets the process very differently. Rather than a recipe for the vegetable stone, Starkey describes a mineral elixir, made using antimony and used for transmutation. Dr Rampling argued that such textual transmutations reveal the attempts of later practitioners to make practical sense of authoritative sources. Over time, the original practice of sericonian alchemy was eclipsed by other methods and materials. This eclipse is one reason why we find few traces in modern scholarship of either sericon or the vegetable stone.
Next, Peter Forshaw (Universeit van Amsterdam) introduced the complexities of ‘Early modern alchemy and cabala’. From the late fifteenth century, a Christianized version of Cabala circulated in Europe through the works of Giovanni Pico della Mirandola and Johannes Reuchlin. This approach was taken up by a number of alchemical writers during the sixteenth and seventeenth centuries, who were interested in its value as an exegetical technique. Whereas Christian interpreters sought to discover additional layers of meaning in scripture, leaving the text itself intact, Jewish Kabbalists transformed the written text by breaking it down into its component parts, then recombining the Hebrew letters (or even parts of letters) according to established methods. For alchemists, these techniques offered a new approach to decoding impenetrable alchemical texts. Indeed, the breaking down and reconstitution of language was seen as analogous to the alchemical reduction and recombination of elements and qualities. Several works attributed to Paracelsus praise Cabala (or ‘Gabala’) as a key to understanding alchemy, perhaps in response to the supposed Mosaic basis of Cabala, which invested the system with a scriptural authority lacking in the ‘pagan’ works of Aristotle and Galen. Dr Forshaw explained how alchemical writers, including Bernard Georges Penot and Heinrich Khunrath, employed Gematria: a Cabalistic exegetical technique whereby the numeric values assigned to each Hebrew letter are manipulated in order to imbue words, and even whole texts, with numerical significance. Such letter-play assigned complex levels of meaning to alchemical terms, such as ‘Azoth’ and ‘Elixir’. However, such usage was attacked by the great critic of alchemy, Thomas Erastus, who held Cabalistic techniques to be appropriate for interpreting scripture, but diabolical in Paracelsian chemistry.
Dr Forshaw argued that the source for many other writers was the Venetian Giovanni Agostino Pantheo, or Pantheus. Pantheus attempted to distinguish various types of metallic transmutation, employing Cabalistic-style techniques to create a ‘higher’ manifestation of alchemy, outlined in his Voarchadumia (1530). Pantheus’ works were admired by many later practitioners, including John Dee, Khunrath, Oswald Croll, and Michael Maier. However, Dr Forshaw noted that there is little support for Cabala being employed in ‘spiritual alchemy’. More often, cabalistic techniques were used for calculating the values of alchemical terms and various quantitative aspects of practice (weights, relative proportions, even dimensions of apparatus); for establishing a philological basis for practical processes; for decoding and encoding terms; and even composing Cabalistic enigmas to tease readers.
The final paper of the morning session was delivered by Stephen Clucas (Birkbeck, University of London), on ‘Margaret Cavendish’s materialist critique of Van Helmont’. Although the chymical philosophy of Jan Baptista van Helmont attracted both support and criticism throughout the seventeenth century, the critique of Margaret Cavendish, Duchess of Newcastle, has been little studied. Her engagement with Van Helmont takes place in thePhilosophical Letters (1664), a work in which Cavendish appears to shore up her own, rather suspect philosophical orthodoxy by attacking the “presumption” of other contemporary philosophers. Dr Clucas argued that Cavendish’s critique of Van Helmont was therefore strategically useful: through Van Helmont she was able to attack both opponents of her own materialist position, and a figure associated with the Puritan movement. Her comments can be usefully compared with those of Robert Boyle. Like Boyle, she criticised Van Helmont’s “strange terms and unusual expressions” as impediments to clear understanding, and disliked his theory of active chemical principles (such as “Gas” and “Archeus”) which lacked corporeal substance. Such immaterial principles were unnecessary in Cavendish’s vitalist conception of an animate, yet material, nature, while for Boyle they could be replaced by corpuscular parts. However, Boyle and Cavendish differed over Van Helmont’s view that chymistry could create new substances. While Boyle accepted this possibility, Cavendish did not. In her view, actions of art differed from actions of nature: the productions of art were therefore both different and inferior.
Although Cavendish’s own natural philosophical account of an animate, eternal matter was theologically unorthodox, she also criticised Van Helmont’s chymical principles as potentially blasphemous. For instance, his belief that voids could be created from and reduced to nothing seemed to challenge God’s creation of the worldex nihilo. Cavendish contrasted Van Helmont’s interpretations of scripture with her own religious orthodoxy, as distinct from the “philosophical liberty” she enjoyed when writing on natural philosophy. In distinguishing between theology and natural philosophy (a distinction which Van Helmont transgressed), Cavendish therefore sought the freedom to be both “a good Christian, and a good Natural Philosopher.” Dr Clucas argued that her critique should therefore be seen as part of a wider polemical project, positioned in a period, following the Restoration, when religious orthodoxy was at a premium.
After lunch, Anna Maria Roos (University of Oxford) gave a paper titled ‘Chemical mechanisms of fossilization in the Royal Society’. In the late seventeenth century, the origins of fossils were discussed by members of the Royal Society, including Robert Plot and Martin Lister. These men argued that forms similar to living beings could be created within rock by the generative power of nature, without any organic origin – for instance, by the existence of mineral-generating ‘seeds’ within the atmosphere.
Dr Roos suggested that these seminal theories were derived from earlier theories of saline chemistry developed by Jan Baptista Van Helmont, for whom salts provided the formative principle of materials. Several influential French chemists, including Joseph Duchesne, had posited the existence of a universal, formative salt responsible for generating minerals. Opinions varied as to this salt’s identity, contenders including nitre, sal ammoniac, and, above all, vitriol derived from pyrites. Lister noticed that pyrites was present in Yorkshire limestone, and in the fossils of that region, and speculated whether pyrites might therefore provide the germinating seed of the ‘formed stones’. In Lister’s theory, volatile salts, generated from pyrites, interacted in the air with intermediary substances (neighbouring minerals, or plant and animal remains), sometimes taking on the form of animals or plants. This theory contradicted that of Van Helmont, who had argued for a water-based formation of minerals. However, Lister’s friend Robert Plot was more receptive to Van Helmont’s theory, suggesting that ‘formed stones’ might grow from salt-containing mineral seeds in either water, earth or air, possible aided by astrological influences. Different salts engendered different forms: thus the spiral shape of an ammonite might result from the interaction of two salts growing in different directions. Dr Roos concluded by noting that, although both Lister and Plot believed that fossils had mineral rather than organic origin, their differing attitudes towards Helmontian saline theories reveal both the complexity of this issue, and the importance of salt in seventeenth-century theories of the generation and transformation of minerals.
Lawrence Principe (Johns Hopkins University, Baltimore) concluded the meeting with a paper titled, ‘Turning Experiments into Theories: The Evolution of Wilhelm Homberg’s Essais de chimie’. The major work of Wilhelm Homberg, chief chymist of the Académie Royale des Sciences around 1700, is his influential chemistry course, the Essais de chimie. By studying versions of the Essais prepared at different times, scholars can gain insight into how Homberg’s theoretical views suggested, and were modified by, programmes of experiment. Professor Principe discussed four versions of the Essais. The best known is that published in the Mémoires de l’Académie Royale des Sciences between 1702 and 1709. However, the manuscript transcript of Homberg’s original presentation to the Académie shows the extent to which Homberg’s views changed before publication: changes which, Professor Principe argued, are related to the experiments Homberg carried out after his presentation, from 1702 onwards. Two more versions were uncovered by Professor Principe in a St Petersburg archive: one, the final, unpublished version of the Essais, written towards the end of Homberg’s life; the second, an earlier version which Professor Principe dated to around 1694 or 1695.
In the early version, Homberg describes four chymical principles of animal and vegetable substances: oil, salt, earth, and water, plus another three for minerals: the Paraselsian ‘tria prima’ of mercury, salt, and sulphur. Of these, Homberg seems to have considered salt to be the most important, and many of his experiments in the late 1690s involve analysis of various salts – probably influenced by Van Helmont. However, by 1699 he had concluded that volatile salts could not be reduced into water, and subsequently moved away from his earlier, Helmontian approach. In his 1702 account, oil has been removed as a principle of animal and vegetable substances, Homberg concluding on the basis of his analyses that oils were in fact composed of salty, earthy and watery parts. He therefore replaced salt with sulphur as the only activating principle in matter, probably as the result of experiments held between 1702 and 1704. Homberg seems to have started investigating the sulphur principle after noticing that a gigantic burning lens, purchased by his patron, the Duc d’Orlèans, turned white metals gold. In 1705, Homberg declared that the active sulphur principle in its free state was light itself, which could be manipulated chemically using the burning lens. In the final version of the Essais, sulphur dominates as the only active principle, and Homberg has also added another passive principle, air. By identifying the sulphur principle as light, and adding air, Homberg therefore included within chymistry subjects usually viewed as part of physics: pneumatics, optics, and acoustics.
Jennifer Rampling
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