Samuel Lytler Metcalfe (1798–1856) was an American chemist and physician who wrote a voluminous work, Caloric Its Mechanical Chemical and Vital Agencies in the Phenomena of Nature (2 vols., London, 1843); attempting to account for all natural phenomena in terms of caloric. The book came out at the time when the concept of caloric was being gradually discarded and the law of conservation of energy was about to appear. Metcalfe was convinced that caloric would be the key to unlock the secrets of nature; in order to develop the practical implications of his views he made research trips twice to England (1831 and 1835–45), and there he completed Caloric.

There is a story, which historians of modern France often tell, of the ministerial official in Paris who had only to glance at his clock in order to know the exact passage of Vergil being construed and the law of physics being expounded in every school throughout the country. Invariably, the story is told for a purpose. It is used to demonstrate the high degree of centralization and the attendant rigidity of the French educational system, usually with special reference to the nineteenth century. The story, which has its roots in the rich corpus of Napoleonic legend, serves this purpose very well, but unfortunately it is both apocryphal and misleading. For while it is true that most nineteenth-century ministers with responsibility for education aspired to the ideal of total control, not one of them came close to it in reality.

Jean Antoine Claude Chaptal was not only a chemical manufacturer and one of the first ‘industrial scientists’ but was also, according to his own testimony, one of the early supporters of Lavoisier's system of chemistry. It might be assumed that Chaptal's pioneering work in industrial chemistry was intimately linked with his acceptance of the oxygen system of chemistry; more specifically, that this theory served to direct and inform his applied research and contributed not a little to its success. Indeed, he himself in 1790 explicitly stated this to have been the case. A close study of his work prior to 1790 fails, however, to establish the importance of such a linkage. First, his selection of research topics proves to have owed little to the ‘new chemistry’ but much to the scientific and economic milieu of his province of Languedoc and of Montpellier, its administrative seat. Second, the significance of his acceptance of the ‘new chemistry’ appears rather problematic, not the least because of the rather hazy boundaries between the phlogistic and Lavoisian theories in the 1780s. Third, it is not clear from the evidence available how the new theory helped solve the various problems of industrial chemistry he faced, or could have done so, other than to offer alternative explanations for processes with which he was already familiar and indeed had often mastered. It will be suggested that it is precisely this less dramatic role which was filled by the new chemistry: that of ‘rectifying’ his ideas by providing alternative and more satisfactory rationalizations of his experiences and experiments in the laboratory and the factory, not that of enabling him to simplify and perfect old processes nor to invent new ones. To put the point more bluntly: Chaptal's early successes and reputation in industrial chemistry were not a by-product of his allegiance to the new chemistry; rather, his growing adherence to that system was a by-product of its ability to provide satisfactory post-hoc explanations of the chemical processes and products with which he was concerned.