Historical Styles of Experimentation and Observation: Historia Experimentalis
In the early modern period, “experimental history” (historia experimentalis) was a collective style of experimentation in addition to experimental philosophy. The “experimental history” as institutionalized in seventeenth-century and eighteenth-century chemistry was a tradition of experimenting, writing, and teaching that evolved around the multiplicity of chemical substances. Like natural history, experimental history collected, described, and ordered facts relating to the perceptible dimension of particular objects and processes. But whereas natural history was concerned with the observation and collection of things “given by nature,” experimental history reported phenomena procured by intervention into nature, both in the arts and crafts and academic laboratories.
An explicit program of “experimental history” first arose in the early seventeenth century when Francis Bacon (1561–1626) became its most prominent spokesman. Bacon outlined his ideas of an experimental history (historia experimentalis) in a text entitled Preparative Towards a Natural and Experimental History, which was published in 1620 in the same volume with the Novum Organon. Experimental history in Bacon’s original sense was, first of all, a collection and description of existing factual knowledge developed in the arts and crafts. It was an inventory of artisanal operations and experiments in the broadest sense, which complemented natural history. Robert Boyle (1627–91), a keen follower of Bacon, also argued that learned men must collect as many facts as possible from craftsmen and merchants.
Robert Boyle, in particular, made efforts to demarcate “experimental history” from its philosophical counterpart “experimental philosophy.” For example, in his Experimental History of Colours (1664), Boyle asserted that his present work will excite its readers by the delivery of “matters of facts,” free from any speculation and explanation. He further added remarks about the method and the literary style of experimental history, which served to further distinguish it from experimental philosophy. Experimental history did not require a structured presentation of facts. If the experimenter was not, or not yet, able to create order among the experimental facts and to discover regularities, he may present them as they came to mind and hand, that is, by “declining a methodical way.” Furthermore, as experimental history in its most rudimentary stage was a mere collection of phenomena engendered by experiments, the extension of experiments must be possible with the greatest “liberty” of action; the experimenter may add new experiments and thereby collect new facts without knowing where the journey will go. Unlike experimental philosophy, experimental history abstained from reduction, conceptual unity, and inquiry into hidden movements and causes.
Boyle’s emphasis on the absence of any speculation and preconceived methods in experimental history, his insistence on the collection of phenomena without any intellectual and methodical constraints, resonated with another broad cultural movement: the historia tradition. The historia tradition had gained momentum in the Renaissance, when physicians and other learned men revalued the empirical description of objects of nature and of human action vis à vis speculation about causes. As Pomata and Siraisi pointed out recently, “historia” offered thorough descriptions of “how things are” without explaining why they are so. It sought to base knowledge on sense perception and aimed at knowledge of particulars.
Furthermore, Bacon’s and Boyle’s emphasis on the importance of technical artifacts and operations was embedded in an ongoing cultural movement that revalued the role played by the methods and accomplishments of artisans for the acquisition of natural knowledge. The technological treatises of the fifteenth and sixteenth centuries on architecture, machines, shipbuilding, and navigation, military instruments, and ballistics, the art of fortification, mining, and metallurgy, alchemy, the art of distillation and so on gave voice to this new attitude, which questioned the Scholastic divide between manual labor and theory, nature and art, certain knowledge (episteme) and technology (techne). Both the historia tradition and Baconian experimentalism stabilized experimental history as a collective style of experimentation and contributed to its institutionalization as an acknowledged academic practice that persisted well into the 19th century.
Historians of science have discussed Bacon’s program of experimental history in connection with the Royal Society’s endeavor to create a “history of trades” in the seventeenth century. But this program also had an impact on the encyclopedic ventures of the Académie Royale des Sciences, such as the large seventeenth-century project on the history of plants, which also included chemical experiments, and the Descriptions des arts et métiers. The more successful Encyclopédie ou dictionnaire raisonné des sciences, des arts et métiers by Denis Diderot and Jean D’Alembert (1751–80) hinged no less on the Baconian program, as D’Alembert’s preface to the Encyclopédie manifests clearly. In addition, the Baconian program of an experimental history also lent intellectual authority to a style of experimentation in the seventeenth and eighteenth centuries that differed from “experimental philosophy.” This second meaning of “experimental history” has largely been ignored in the existing historical literature.
The distinct style of experimentation in the tradition of experimental history can be discerned especially well in the history of chemistry from the seventeenth century to the early nineteenth century. In the chemistry of this period, experimental history meant a collection of phenomena or facts about a great number of particular substances from all possible practical areas, ranging from artisanal sites and everyday life to the academic chemical laboratory. Chemical experimental history was concerned with the preparation, the practical uses, and the properties of substances—that is, their color, smell, taste, consistency, measurable physical properties, and the plethora of chemical properties. It meant an extension of objectives of natural history to a laboratory science, which, like the classical domains of natural history—botany, zoology, and mineralogy—was concerned with a great multiplicity of things. Its target was neither hidden causes nor imperceptible entities (such as the vacuum, forces, atoms, electrical fluids, and other typical philosophical objects of “experimental philosophy”), but the perceptible dimension of materials and operations. And its objective was not philosophical knowledge, but connoisseurship of materials, their varieties, properties, chemical transformations, and practical uses.
Well into the nineteenth century, chemists often performed experiments on a broad variety of different substances, knowing that they would not, or not yet, be able to unravel regularities and general chemical laws, or to improve chemical theories. One day they would study a mineral water from a nearby spring, the next day an iron ore from a new ore deposit, then test the quality of a dyestuff produced in a local manufactory, distill rosemary to reproduce the essential oil of rosemary sold in apothecary’s shops, and afterwards study the chemical properties of apothecaries’ ordinary ether and compare it with ethers prepared in slightly different ways in their laboratories. Their experiments turned from the study of a material belonging to one class to that of another class, and from the kingdom of minerals to vegetables and to animal substances, and vice versa. Compared with experimental philosophy in the seventeenth and eighteenth centuries, and compared also to the “experimental systems” (Rheinberger) in the modern laboratory sciences that evolve around one coherent scientific object and cluster of questions, this style of experimentation may at first glance appear as aimless artisanal tinkering or mere cookery. As it contributes little to heroic historiography it has been largely obliterated from historical research. Most historians of chemistry have highlighted episodes of eighteenth-century chemical experimentation in which experiments were more systematically focused on one scientific object and interconnected to a coherent “investigative pathway” (F.L. Holmes). However, the scientific careers of the vast majority of chemists from the seventeenth century until the first decades of the nineteenth century show that, as a rule, chemists’ experiments studied a great number of different substances, and often changed from one substance to the other without organizing their experiments into a systematic investigative pathway.