Materials in Eighteenth-Century Science: A Historical Ontology (review)

The goal of this study, as the authors note in the introduction, is an ambitious one: "to write a history of the most significant scientific objects of classical chemistry—chemical substances—covering European chemistry in the time period from the beginning of the eighteenth century until the early nineteenth century" (9). During this "long" eighteenth century, home to the Chemical Revolution of the 1770s and 1780s, the development of most major chemical concepts and theories did indeed revolve around "substances," as opposed to modern day atomism or to the previously upheld corpuscularian and hypostatical elemental theories that were widely spread during the Middle Ages and the Renaissance. Given the vastness and diversity of the realm of eighteenth-century chemical substances and their ways of production and manipulation, the study focuses on a comparative-analytical exploration of the "chemists' modes of identifying and classifying materials" (9). While the subject, in its chronological embrace and methodological approach, comprises a challenging scholarly undertaking, the result is both impressive and rewarding. Klein and Lefèvre's analysis is a brilliant exemplar of how philosophical insights can complement and enrich a rigorous treatment of historical sources; their study bears witness to the intellectual prowess held by a sensitive fusion of the history and philosophy of science.

In a sense, to use a well-known literary distinction, this study is less concerned with telling or arguing (establishing one particular hypothesis) than with showing or substantiating (by way of a nuanced interpretation of contemporary chemical classificatory schemes and practices) the role of material entities in chemical theory and method: their origins, production, detection, manipulation, and changing definitions. This is not to say that the narrative is descriptive or devoid of analytical insights; that can hardly be the case in a work that interweaves the history and philosophy of classifications of material knowledge and their evolution vis-à-vis the chemical experimental and observational domains. It is rather meant as an attempt to provide an image of Klein and Lefèvre's "historical ontology" of eighteenth century chemical substances.

The study is divided into three parts. Part 1 (chapters 1–3) sets the background to both subject matter and historiographical approach. The authors delineate three practices of studying materials in the eighteenth century: natural history (non-interventional collection of observational instances), experimental philosophy (inquiry into the imperceptible dimension of substances by way of instrumental intervention), and technological improvement (evolution of instrumental and laboratorial practices). Eighteenth-century chemists, it is claimed, "constituted multidimensional objects of inquiry by interconnecting [these] three styles of experimentation and observation," which the authors aptly designate as "experimental history" (21). The claim for this multidimensionality forms a corrective antidote to previous historiography, which tended to distinguish more rigidly between the "three styles," thus glossing over finer metaphysical and epistemological commitments of eighteenth-century chemists; Joseph Priestley's pneumatic enterprise is a good case in point. In providing an account of some late-seventeenth century matter theories and classification strategies—which drew upon corpuscularian-qualitative views as well as the corporeal/spiritual distinction—the authors highlight the shift of eighteenth-century chemists from the study of the perceptible to the imperceptible dimension of substances and vice versa, as tightly linked to a novel understanding of concepts such as "compound," "composition," and "analysis." Consequently, chemical affinity and electivity gained increasing prominence in demarcating, for the eighteenth-century chemist, "imperceptible movements of building blocks of preserved substances and their aggregation to new chemical compounds from mere mechanical mixtures" (49). The distinction between physico-mechanical aggregation and chemical composition is a crucial yet largely overlooked theme in the history of early modern chemistry. As a comparative longue durée exploration of classification strategies—focusing on organization of chemistry lectures, textbooks, lists, and tables—the study uncovers such distinctions as well as other ontological shifts and sheds light on their relationship to scientific practices.

Part 2 (chapters 4–10) is dedicated to a genealogical and (con-)textual analysis...