Chemistry and Cannon: J.-L. Proust and Gunpowder Analysis SEYMOUR H. MAUSKOPF D’un instrument de guerre à un instrument de labo ratoire, les affinités ne changent certainement pas. [J.-L. Proust, “Cinquième mémoire sur la poudre à canon,” Journal de physique, de chimie et d’histoire na turelle 73 (novembre 1811): 390] This is the story of an attempt by a major chemist of the late 18th century to develop “useful knowledge” for industry under govern ment patronage. The chemist was Joseph-Louis Proust (1754—1826; known as Luis José Proust in Spain); the industry was munitions; the government was Spanish. It is not a success story in any simple sense; Proust’s research did not bring about any change in the manufacture of gunpowder (although Proust rather passionately argued for some reforms based on his experiments) and his work on gunpowder has been all but forgotten. Yet, on closer scrutiny of Proust’s career, I came to realize the significance of the gunpowder research for it. Although Proust is best known for his work in analytical chemistry (the enunciation of the law of definite proportions, a basic principle of chemical stoichiometry), he carried out research and taught on a wide range of chemical topics, many of them practical. Indeed, it was primarily through his practical chemistry that Proust was enabled to spend his mature and most creative years in Spain in the employ of the Spanish government. Of central importance were his activities as researcher, consultant, and teacher concerning munitions, carried on when he was professor of chemistry at the Royal Artillery School in Segovia (1785—98). Proust Dr. Mauskopf is professor of history at Duke University and, in 1988—89, was Edelstein International Fellow in the History of Chemical Sciences and Technologies at the Beckman Center for the History of Chemistry and the Edelstein Center, Hebrew University of Jerusalem. He is currently researching scientific involvement in explo sives and munitions from the late 18th century through World War I. He thanks the secretarial staffs of the Duke Department of History and of the Beckman Center for their expert services; and Alex Roland, Joe Burchfield, and the Beckman Center “brown bag seminar” for their helpful, frank readings of various drafts of the article.© 1990 by the Society for the History of Technology. All rights reserved. 0040-165X/90/3103-0003$01.00 398 Chemistry and Cannon: J -L. Proust and Gunpowder Analysis 399 certainly did not regard his practical chemistry as any less important than his “pure” chemical analysis; as we shall see, he placed high value on his gunpowder research. In fact, this research was probably the most comprehensive and systematic study of gunpowder chemistry of its day. Moreover, it was part of a scientific research tradition devoted to the elucidation of the physics and chemistry of gunpowder that spanned the 18th century.1 Therefore, one of the objectives of this study is to present and analyze Proust’s scientific research on gunpowder for its intrinsic scientific interest and significance. That this work has been neglected is only partly due to its limited application to the munitions industry in its own day; it is also a part of the general neglect that the history of modern scientific investigations of munitions has suffered. The classical study by J. R. Partington has for its focus the medieval and early modern eras and is very sketchy about the history of gunpowder after 1700.2 To discover information about the later period, one is forced to turn to state-of-the-art treatises of the 19th century, with their inevitable “textbook” orientation to the history of science.3 This study and its companion in Osiris are intended to provide partial redress for the shortcomings in the history of the scientific study of munitions. There is also a second objective related to the state patronage of Proust as practical chemist: the examination of Proust’s gunpowder research as a species of the “useful knowledge” so prized by 18thcentury reformers, bureaucrats, and entrepreneurs. There has devel oped a vast literature on the issue of the relationship between science and industry encapsulated by this phrase. Much of it has focused on 'Seymour H...