In Éléments de l'art de la teinture, Claude-Louis Berthollet organized and described knowledge of a chemical craft in terms of contemporary chemical science. The resulting intellectual structure of his treatise established a programme and method for the subsequent improvement of dyeing. Berthollet's descriptive and hierarchical systematization of knowledge rendered problems intelligible and isolated them so that they could be attacked and solved by methodical experimentation. This double-edged processes of solving practical problems, first cognitively and then experimentally, provides a key to (...) understanding the way science has contributed to rapid and systematic technological change. (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)

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)