SHAUL KATZIR* Employment Before Formulation: Uses of Downloaded from http://online.ucpress.edu/hsns/article-pdf/49/1/1/377888/hsns_2019_49_1_1.pdf by Max Planck Institute for the History of Science user on 15 June 2021 Proto-Energetic Arguments ABSTRACT The historiography of the principle of energy conservation has concentrated on the formulation of the law by a few individual scientists. This paper turns to the employment of energetic considerations, examining the uses of related arguments in scientific reasoning before the formulation of a well-defined principle. It shows that conceptual ambiguity and a limited formal realm of validity did not prevent the successful employment of such notions to generate novel scientific results. From the late 1810s to the 1840s, researchers including Fresnel, Ampe` re, Carnot, Roget, Faraday, and Liebig invoked proto-energetic arguments to address particular pro- blems concerning wave optics, electromagnetism, theory of electric batteries, heat motors, and animal heat. Thereby they extended the realm of applicability of argu- ments based on the conservation of “power” beyond non-frictional mechanical systems, where the conservation of the living forces (vis viva) was accepted in the early nineteenth century; they also furnished scientists a theoretical toolkit with a new powerful method. Their development of proto-energetic arguments as tools for reasoning was an important historical process in itself, which together with other developments led to the emergence of “energy physics.” This history, thus, exem- plifies the important role played by practices of reasoning in the formation of scientific laws and principles. KEY WORDS: energy conservation, principles, rational mechanics, electrodynamics, Andre-Marie´ Ampe`re, Augustine Fresnel, Justus Liebig, Michael Faraday *The Cohn Institute for the History and Philosophy of Science and Ideas, Tel Aviv University,
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