The ArgumentMost historians of science share the conviction that the incorporation of the corpuscular theory into seventeenth-century chemistry was the beginning of modern chemistry. My thesis in this paper is that modern chemisty started with the concept of the chemicl compound, which emerged at the end of the seventeenth and the beginning of the eighteenth century, without any signifivant influence of the corpuscular theory. Rather the historical reconstruction of the emergence of this concept shows that it resulted from the reflection (...) on the chemical operations in the sixteenth-century metallurgy and seventeenth-century pharmacy. I argue that the reversibility of these operations and their understanding as crafts (metallurgy) or chemical arts (pharmacy) were decisive factors for the emergence of the first ideas about chemical compounds in the seventeenth-century pharmaceutical works written by pharmaceutically trained authors, influenced by the Paracelsian image of nature. There is a direct line of descent from these authors to E.F.Geoffroy (1675–1742), who integrated the first scattered ideas of chemical compound into a general concept comprising chemical artefacts as well as natural bodies. (shrink)

In this paper it is performed a historical account of the theoretical roots that grounded the following four key basic ideas of chemical equilibrium: ‘incomplete reaction’, ‘reversibility’, ‘equilibrium constant’ and ‘molecular dynamics’. These notions developed in nineteenth-century as a consequence of the evolution of the concept of chemical affinity. The discussion begins with the presentation of the earliest affinity table [‘Table des rapports’] published in 1718 by Geoffroy. Afterwards, it is examined Bergman’s compilation. The theory supporting this arrangement assumed that (...) chemical displacement reactions were complete and could not be reversed. It is analysed how Berthollet’s model showed the inadequacy of this view. His new conceptual considerations established that the amount of the substances involved in a reaction was an essential factor determining its direction, which accounted for the early concepts of incomplete reaction and reversibility. Guldberg and Waage specified the role of mass in chemical equilibrium reactions as they considered the concentrations of the chemicals involved, formulating the first chemical equilibrium mathematical equation that approximates what is called nowadays chemical equilibrium constant. Finally, it is presented how Pfaundler was the first to consider the kinetic theory in the interpretation of the macroscopic properties of equilibrium reactions. (shrink)

E.F. Geoffroy's table of different relations ( rapports ) between different chemical substances is mainly based on empirical knowledge accumulated in 16th and 17th century metallurgy and pharmacy. The substances listed in the left half of the table were basic for the formation of salts which were produced for medical ends in the chemical-pharmaceutical practice of the 17th century. The right half of the table refers to substances and operations of metallurgy which had already been described in the metallurgical writings (...) of the 16th century. Even Geoffroy's ordering of the substances within the columns of his table has its origin in metallurgical and pharmaceutical practice. The key concept of the conceptual framework underlying the table and its commentary is the concept of chemical compound which emerged at the end of the 17th century. Geoffroy extends the range of application of this concept, which was first limited to chemical artefacts, to include natural bodies. Eliminating the peripatetical distinction between natural bodies and chemical artefacts he formulates a new research program, consisting in the determination of the laws of the relations ( rapports ) between different chemical substances. (shrink)

The ArgumentEtienn-François Geoffroy' Table des Rapports is generally regarded as a landmark in the evolution of chemistry during the eighteenth century. Issues have arisen among historians concerning the significance and originality of the Table that require fuller attention to the immediate context of chemical research in the Academie des sciences during the two decades that preceded its appearance. The present paper argues that, despite the transition from communal to individual research projects that marked the reorganization of the Academy in 1699, (...) chemists continued to pursue shared problems within a communal ethos. The interactions between Wilhelm Homberg, Etienne-François Geoffroy, and Louis Lemery were particularly prominent. The paper traces one example of this interaction, involving the sulfur principle and its influence on one entry in Geoffroy's Table. Further such studies are needed to elucidate the relation between the concepts of chemical composition and reactions implied in Geoffroy's table and the concepts embodied in the previous work of Geoffroy and his associates in the Academy. (shrink)