Experimenting with Chemical Bodies

A review of Experimenting with Chemical Bodies: Science, Medicine, and Philosophy in the Long History of Reinier de Graaf’s Experiments on Digestion, from Harvey and Descartes to Claude Bernard, by Evan R. Ragland.

As the title of this thesis suggests, Evan Ragland aims to trace the history of experiments on digestion over almost three centuries. In doing so, he draws on recent work on early modern experiments by William R. Newman, Robert Frank and Anita Guerrini, and he adds to other existing histories of experimental practices and ideas. Moreover, Ragland bases his research on the work of a number of Dutch historians of medicine, such as Harm Beukers, Gerrit Arie Lindeboom, and Mart van Lieburg, combined with a wide array of primary sources. What makes his approach unique is the span of time over which he traces the history of Reinier de Graaf’s (1641-1673) experiments, and this thesis shows the added value of thinking of a cluster of experiments as a “character.” Ragland immediately recognizes that treating de Graaf’s experiments as an entity that can be traced through time and place is not entirely unproblematic, but correctly points out that they were indeed an actor’s category to the experimental physiologists of the nineteenth century, who worked with and within historically defined techniques and ideas.

The dissertation is woven around four themes: experimentation, Cartesian mechanism, chemistry and life, and the role of historical reflection in scientific practice. In the first two chapters, the stage is set for de Graaf’s work. In Chapter 1, Ragland explores early experimental anatomy in Leiden in the wake of William Harvey between 1638 and 1658. After a survey of Cartesianism in the Low Countries, he describes how the Leiden professors Antonius Walaeus and Franciscus dele Boë Sylvius collaborated on tracking down the origins of the blood in nutrition. Ragland shows that strict mechanical reduction and Cartesian corpuscular explanation remained the ideal for Sylvius, whose medicine was grounded in a chemical acid-alkali theory based on Van Helmont’s work, even though this was not always compatible with the realities of experiment. Moreover, Ragland rightly stresses the important role of anatomical experiments performed by talented students, which made Leiden into a flourishing site of discovery in the seventeenth century.

The second chapter draws a more detailed image of the experimental culture in Leiden in the 1660s, focusing on De Graaf’s and Sylvius’ experiments. Starting with a biography of De Graaf, Ragland explains how de Graaf got involved in the experimental culture at Leiden University, and how he was influenced by Sylvius. In this chapter the epistemic importance accorded to vivisectional discoveries by students in seventeenth-century Leiden and their unpredictability becomes even more acute. It also makes clear that the sites of experimentation were not necessarily within the university walls, and that students and professors shared their findings almost instantly. A thorough discussion of Sylvius’ experimental anatomical and chemical work that informed his new chemical medicine shows that, unlike his contemporaries — most of whom still relied on the Galenic faculty of attraction to explain the function of the organs — Sylvius presented a purely chemical picture of the action of digestion, respiration, innate heat, and the glands.

With the tools and training provided by Sylvius and Leiden University described in the first two chapters as context, Chapter 3 is a survey of de Graaf’s “dog apparatus” and the importance of taste-assay. After de Graaf’s discussions of the anatomy of the pancreas are placed in context, a detailed analysis of his experiments on what Ragland calls “chymical animals” follows. This is a particularly interesting section, as it shows that de Graaf understood his animal subjects as manipulable apparatus, notwithstanding the obvious trouble he encountered in stabilizing them to create reliable experiments. The innovative aspect of de Graaf’s experiments was that he not only intervened in living animals, but that he also kept them alive and even returned them to something resembling normal functioning. This enabled him to collect enough uncorrupted pancreatic fluid in a phial attached to the living dog — its vital heat functioning as a sort of chymical furnace that determined the amount of pancreatic juice produced — to analyze it by tasting it. Tasting was essential for de Graaf and his contemporaries to determine the chymical nature of the pancreatic juice, as its acidity helped him explain its function in the body: it thickened the blood and tempered the effects of the alkaline bile, and together, de Graaf argued, pancreatic juice and bile produced a chymical effervescence in the intestines. Like his predecessors, de Graaf understood the pancreas as the primary source of acidity in the body, and combined with the results from his taste experiments, this allowed him to develop a pathology and therapy of the pancreatic juice. Ragland convincingly demonstrates that although investigative tasting was a centuries-old practice, a new understanding of flavors in terms of chymical principles meant it begot a new rationalization, and the traditional Hippocratic humors were thus given new meaning as chymical principles in the seventeenth century.

Although de Graaf’s conclusions about the nature and therapy of the pancreatic fluid were the subject of heated debate during his lifetime and after his death, his experiments and skill would continue to inspire researchers. Chapters 4 and 5 show this by connecting de Graaf’s work to Ivan Pavlov’s “dog technologies.” Chapter 4 minutely details contemporary attacks on de Graaf’s conclusions about the pancreatic juices, among others from his former colleague and friend Jan Swammerdam. From this, it becomes clear that there was no such thing as “the” acid-alkali theory, but rather a family of related acid-alkali systems, most notably the universalized acid-alkali theory of Otto Tachenius, which was criticized by Robert Boyle. Relating a number of persuasive examples, Ragland argues that the universal and localized versions of acid-alkali theory were defined by larger programs of philosophical explanation, as well as changing notions of the qualities of acids and alkali, and the diverse uses of experiment. Meanwhile, de Graaf’s dog-apparatus and taste-assaying continued to be used as a model for experimental anatomy and medicine, but Johannes Nicolaus Pechlin and Johann Conrad Brunner in the 1670s and 1680s published a series of works that downplayed the importance of the pancreas based on exactly these methods, and de Graaf’s central claims, already criticized during his life, were quickly refuted after his death. In the last section of this chapter, Ragland gives a brief but thought-provoking analysis of Herman Boerhaave’s metaphorical and literal take-over of Sylvius’ position and his attempts to distinguish himself from Sylvius through rhetoric. Finally, this chapter shows that notwithstanding ongoing debates and rivalries, de Graaf’s dog-apparatus lived on as an icon and method of experimental investigation in the eighteenth century.

Chapter 5 relates the resurrection of de Graaf’s dog-apparatus in the nineteenth century. Ragland shows that there is a distinct gap in research on the pancreas in the eighteenth century. Related digestion experiments by René de Réaumur and Lazzaro Spallanzani in this period did not result in considerably new conclusions, and chemical experiments were increasingly and widely employed to study digestion. Subsequently, early-nineteenth-century work building on these eighteenth-century approaches and adopting older techniques used both historical reconstructions and the new apparatus from chemistry to study digestion experimentally. Ragland discusses the work of five early-nineteenth-century researchers of digestion to demonstrate their reliance on de Graaf’s original methods. Most fascinating here are William Beaumont’s (1785-1853) experiments on a human subject, a trapper who survived a musket wound that left him with a gastric fistula that allowed Beaumont to study human digestion and gastric fluids relatively easily. In this section, Ragland shows that even in the work of Claude Bernard (1813-1878), de Graaf’s influence is still notable, and he suggests that acid-alkali physiology could be traced from van Helmont to Bernard, an interesting idea that deserves future attention from historians of science. Ivan Pavlov (1849-1936) was Bernard’s protégé, and he in turn created his own dog-technologies to obtain and study gastric juices both in vivo and in vitro, and once again relied on tasting as a means to define the nature of the juices. Finally, Ragland demonstrates that nineteenth-century physiologists, particularly Bernard, used their understanding of historical methods and experiments to underscore the novelty and usefulness of their new physiology.

In his conclusions, Evan Ragland returns to the themes set out in the introduction, and recounts the slightly ambivalent nature of the nineteenth-century engagement with early-modern investigative techniques and doctrines — they were both resource and constraint. Subsequently, he draws attention to the tendency to reject reductive mechanism in favor of chymistry in the seventeenth century and to why chymistry corresponded best to living phenomena and allowed for productive investigations. As the author himself points out, the novelty of his study is particularly that it shows that the nineteenth-century leaders of experimental medicine revived the practices and tools of the seventeenth-century investigators. A number of issues should be considered in this context. Although multilayered and diverse, forms and styles for reporting experiments were continuous and fairly consistent. The manual skill and inventive ability to construct difficult experiments that originated in the work of de Graaf continued to be highly valued in the long history of medical experimentation. Ragland concludes that experimentation was mobile, both a method of demonstration and an open-ended method of inquiry. It could travel between philosophical and cultural frameworks, even over a long period. Yet the distinction between the processes of living things from those of non-living things sets the modern researchers apart from their early modern counterparts.

A reflection on historiography and some suggestions for future research form the finale of the thesis. Based on the continuity of some aspects of seventeenth-century experimentation into the nineteenth century, Ragland objects to Andrew Cunningham’s thesis that there was a strong discontinuity in science around 1800, as well as to Michel Foucault’s argument that a “clinical gaze” emerged around the same time. He offers an alternative theory of complex continuity and discontinuity instead, that is more in line with Nicholas Jardine’s common-sense ontology. Identifying Steven Shapin and Simon Schaffer’s Leviathan and the Air- Pump: Hobbes, Boyle, and the Experimental Life (Princeton, NJ: Princeton University Press, 1985) as an example of a local, synchronic study that attempts to identify the cultural beginnings of scientific practices with limited success, Ragland suggests that long-term studies are the only manner in which we can locate and demonstrate historical emergence. Moreover, he argues that long-term studies have additional advantages, such as accounting for the revisability and open-endedness of experimentation, as well as for its manual, somatic character and competitive and collaborative nature. These are valuable suggestions and Evan Ragland’s thoroughly researched thesis is a very welcome addition to existing studies of early modern experiments, not least because it persuasively shows how experimental practices function as historical entities with much more complex continuity than expected.

Marieke M.A. Hendriksen
ICOG (Groningen Institute for the Study of Culture)
University of Groningen, The Netherlands

Primary Sources

Museum Boerhaave, Leiden
Leiden University Library special collections
The College of Physicians of Philadelphia Library
University of Pennsylvania Library
The Chemical Heritage Foundation

Dissertation Information

Indiana University. 2012. 604pp. Primary Advisor: Domenico Bertoloni Meli.

Image: Reinier De Graaf, Tractatus anatomico-medicus de succi pancreatici natura et usu. Leiden, 1671.

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