The historical problem of the development of physics and chemistry as separate disciplines has been insufficiently analyzed. While there have been some studies of specialized disciplinary formation, for example, in physical chemistry, radioastronomy, and molecular biology, few historians or sociologists have tackled the historical bifurcation of physics and chemistry or the nature of their interactions over long periods of time.¹

The category of “discipline” is useful because it carries conceptual, social, and psychological meaning. The French historian and philosopher Michel Foucault especially focused attention on the idea of the relation of knowledge to “disciplines,” much as the American historian and...

On the whole, late-nineteenth-century physicists tended to think of chemistry as a descriptive science in need of physical foundations. Maxwell characterized chemistry as a science lacking clarity and rigor, that is, insufficiently abstract.¹ Hermann von Helmholtz expressed the opinion that chemistry as a science progresses “not quite rationally.”² These views were in keeping with late Enlightenment traditions in the classification of knowledge. As noted in the introduction, Kant wrote that theoretical reason includes mathematics and physics (Physik), the principles of which are a priori synthetic judgments. One encounters “genuine science only to the extent that one encounters mathematics in it.”³...

The term “chemical philosophy” was often used in the eighteenth and nineteenth centuries, but what did it mean, and how did its meaning change during this period? Clearly, there were parallels of meaning conceptually between the terms “natural philosophy” and “chemical philosophy,” but there also were important differences, particularly as the two distinctive identities of chemistry and physics began to emerge during the first decades of the nineteenth century. We focus now on the changing aims and methods of chemistry, or on the epistemology of chemistry, during much of the nineteenth century.

Philosophers and historians interested in science mostly have...

Charles Peirce distinguished three kinds of signs: the icon, the index, and the symbol. According to Peirce, the icon conserves the element, or prototype, represented. The index recalls the prototype by indirect means of empirical connections. The symbol evokes the prototype by pure conventions and a system of re1ations.¹ These categories are a useful starting point in thinking about the language and imagery of the chemical discipline in the nineteenth and twentieth centuries.

“Icon” originally referred to paintings, sculpture, or other artwork depicting angels or saints in the Eastern Orthodox church. The modern semiotic meaning of “icon” is broader; the...

The conventional account of the origins of physical chemistry is reiterated by one of the discipline’s preeminent twentieth-century practitioners, Henry Eyring, in an essay celebrating the centennial of the American Chemical Society in 1976. “Unofficially physical chemistry is as old as efforts to improve cooking or to develop the implements of peace or war. Yet its more formal beginning, around 1887 [when theZeitschrift für physikalische Chemiewas founded], was only a little later than the birth of the American Chemical Society.” The founders were Svante Arrhenius, Wilhelm Ostwald, and J. H. van’t Hoff. “These three great men from Sweden,...

The first chair of theoretical physics in France was the professorship established for Pierre Duhem in 1894 at the Bordeaux Faculty of Sciences.¹ Duhem was well known in French scientific circles not only as a physicist but as a physicist of exceptional mathematical skills who addressed himself early in his scientific studies to chemical problems. He wrote a controversial doctoral thesis (1886) in which he developed the concept of thermodynamic potential for chemistry and physics, and he later developed a treatment of equilibrium processes formally analogous to the mechanics of Lagrange. The goal was to make mechanics a branch of...

In his inaugural lecture for the chair of theoretical chemistry at Oxford in 1973, Charles Coulson recalled a student asking him, “Why are you not located in physical chemistry?” Nernst and other physical chemists at the turn of the century had thought of physical chemistry as theoretical chemistry. In contrast, by 1970, as Coulson put it, “the theoretical chemist is concerned not just with physical chemistry but with all branches of chemistry.”¹

Coulson’s generation of theoretical chemists was equally at home in physics, mathematics, and chemistry. What clearly distinguished his generation from the preceding generation of theoretically minded chemists was...

Like Arthur Lapworth, and unlike Thomas Lowry and Robert Robinson, Christopher Ingold was a scientist comfortable in the laboratory domains of both physical chemistry and organic chemistry. As his student, Derek Davenport, remarked in 1987, lngold became the clear leader of the “emerging discipline” of physical organic chemistry when he “harnessed chemical kinetics to his discussions of reaction mechanisms”:

His magisterial review, “Principles of an Electronic Theory of Organic Reactions” . . . was a kind of legal brief describing the way physical organic chemistry ought to be if only God had done his work properly. Now more than fifty...

Niels Bohr’s 1913 hydrogen atom paper demonstrates the traditional interest of some physicists in placing the facts and laws of chemistry within a broader framework of foundational principles laid out by physicists. During the course of the next two decades, a number of physicists who became known as quantum physicists developed physical theories and mathematical techniques that they claimed would create a mathematical and theoretical chemistry. However, few of them had much chemical knowledge beyond a general understanding of the periodic table of the elements and familiarity with the Lewis-Langmuir theory of the electron duplet and octet.

Among the physicists...

In 1930, the student Charles Coulson wrote out as the first lines of his chemistry exercise book at Clifton College in Bristol, “Physics is Chemistry. Chemistry is Physics. Laws of Conservation of energy and matter are FUNDAMENTAL LAWS. Lavoisier was the first to realize this clearly.”¹ Almost sixty years later, the editors of theAnnual Review of Physical Chemistryannounced that they had entertained the suggestion that “Chemical Physics” be added to the title of the journal but rejected it, even while recognizing, they said, that the difference between the practice of physical chemistry and chemical physics is “small indeed.”²...