Théophile De Donder, a Belgian mathematician born in Brussels, elaborated two important ideas that created a bridge between thermodynamics and chemical kinetics. He invented the concept of the degree of advancement of a reaction, and, in 1922, he provided a precise mathematical form to the already known chemical affinity by translating Clausius’s uncompensated heat into formal language. These concepts merge in an important inequality that was the starting point for the formalization of non-equilibrium thermodynamics. The present article aims (...) to reconstruct how De Donder elaborated his ideas and developed them by exploring his teaching activity and its connection with his scientific production. Furthermore, it emphasizes the role played by the discussions with his disciples who became his collaborators. The paper analyzes De Donder’s efforts in participating in the second Solvay Chemistry Council in 1925 to call the attention of chemists to his mathematical approach. We explain why his work did not receive much attention at the time, and how, despite this, his formalization of chemical affinity became the basis for the birth of the so-called Brussels school of thermodynamics. (shrink)

After Lavoisier's execution, the leading French chemists were Antoine-François Fourcroy , Louis-Bernard Guyton de Morveau and Claude-Louis Berthollet . At the beginning of the nineteenth century, Berthollet introduced a new conception of chemical change that challenged the theory of elective affinities which had dominated chemistry for nearly a hundred years. Berthollet's new affinities raised controversy among chemists and had to coexist with the firmly established theory of elective affinities. Apart from the public debate in research articles, (...) Berthollet's affinities also had to compete with the influence of Fourcroy and his school in the textbook market. This paper seeks to assess the extent to which French textbooks published at the beginning of the nineteenth century were committed to Berthollet's innovation, and how they contributed to its marginalization. (shrink)

Summary This paper presents a case study that contributes to the current debate among historians of chemistry concerning the role and influence of pedagogy in science. Recently, Bernadette Bensaude-Vincent and her colleagues concluded that in nineteenth-century France, ?textbooks played an important role in discipline building and in creating theories?.1 Developing this idea further, this paper examines the dissemination of knowledge through face-to-face chemical lectures, showing that the influence of pedagogical strategy on theoretical content of the science is far from (...) negligible. The pedagogy of William Cullen was essentially responsible for the prevalence of the doctrine of affinity in British chemistry from the 1760s onwards. Cullen used his affinity theory as a pedagogical tool that to a large extent defined his discipline, and the pedagogical pyramid that he headed similarly ensured that the doctrine would remain at the heart of British chemistry. From a pedagogical tool, the doctrine of affinity was transformed over time into a chemical tool, offering British chemists a disciplinary common ground that both set and reinforced the boundaries to their discipline. 1A. Garcia-Belmar, B. Bensaude-Vincent and J.R. Bertomeu-Sánchez, ?The Power of Didactic Writings: French Chemistry Textbooks of the Nineteenth Century?, in Pedagogy and the Practice of Science: Historical and Contemporary Perspectives, edited by D. Kaiser (Cambridge, MA, 2005), 243. (shrink)

Ursula Klein has argued that Geoffroy’s table of chemical affinities, published in 1718, marked the emergence of the concepts of chemical compound and chemical combination central to chemistry. In this paper her position is summarised and then modified to render it immune to criticism that has been levelled against it. The essentials of Geoffroy’s chemistry are clarified and adapted to Klein’s picture by way of a detailed comparison of it with Boyle’s corpuscular chemistry that proceeded Geoffroy’s (...) by over half a century. The idea that Geoffroy’s notion of chemical combination marked a significant turning point in the emergence of modern chemistry is defended against the charge that it is Whiggish. (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)

In the 18th century, the concept of ‘affinity’, ‘principle’ and ‘element’ dominated chemical discourse, both inside and outside the laboratory. Although much work has been done on these terms and the methodological commitments which guided their usage, most studies over the past two centuries have concentrated on their application as relevant to Lavoisier's oxygen theory and the new nomenclature. Kim's affinity challenges this historiographical trajectory by looking at several French chemists in the light of their private thoughts, public disputations (...) and communal networks. In doing so, she tells a complex story which points to the methodological and practical importance of industrial and medical chemistry. The following review highlights the advantages and snares of such an approach and makes a few historiographical points along the way. (shrink)

Chemical affinity is by itself inclusive of the action of a sign. Naturalization of the action of a sign is latent in the material organization holding its own identity by means of the exchange of material. A concrete experimental example is the citric acid cycle running in the absence of biological enzymes. The carbon atoms to be exchanged round the cycle serve as the signs for holding the cycle as a natural system. The action of a sign operates in (...) the present progressive tense and is also descriptively approachable in the same tense, as implying that a natural system holding its own identity assumes the first-person status acting for its own sake. The action of a sign is thus addressable in first person descriptions on the level of the supporting material system that can recognize the sign as such from within. Furthermore, if the action of a sign happens to precipitate the record registered in the present perfect tense, the record itself will be approachable in third person descriptions in the present tense. When one can relate the record of an earlier event to that of a later one, what is called information will come up. Information to be externalized and objectified is about the completed outcome from the action of a sign that is accessible in third person descriptions in the present tense. Conversely, if the action of a sign is carried by a natural system holding its own identity in a manner to be registered in the present perfect tense after the event, information will appear in a proper form of bookkeeping as relating the memory to anticipation on the part of the material agency. Although information in the present has the capacity of relating the past to future in the present tense as avoiding direct confrontation with the dynamic nature of the present or now head on, the action of a sign facing the present squarely is competent enough to address and decipher the generative capacity of information itself operating in the present progressive tense. (shrink)

This paper presents a numerical study of the reaction A ↔ B in the presence of an intermediate and destabilizing step in its dynamics. After introducing a direct autocatalytic destabilizing process, namely quadratic autocatalysis ) and cubic autocatalysis ), a thermodynamic analysis of the evolution of the reaction in closed and open systems was performed. In addition, the Gibbs free energy, the thermodynamic affinity, and the entropy generation of the overall reaction were evaluated for each of the autocatalytic steps, in (...) order to analyze the behavior of these thermodynamic quantities when the system moved towards equilibrium or towards oscillatory non-equilibrium states. (shrink)

The usual account of Auguste Comte, thinker of the “positive” science, overshadows his attention to the “spectacle of destruction”, to which the metaphysical state of human knowledge and humanity offers the stage. I first illustrate the understanding of this Comtian metaphysical state as both a progressive and self-destructive transformation of “theology”, using an example drawn from the history of astronomy. The broader relevance of this conception is then assessed in the field of social philosophy, so that the realm of natural (...) sciences is finally re-examined with the analysis of Comte’s criticisms of the theory of chemical affinity. (shrink)

The usual account of Auguste Comte, thinker of the “positive” science, overshadows his attention to the “spectacle of destruction” (and of obsolescence), to which the metaphysical state of human knowledge and humanity offers the stage. I first illustrate the understanding of this Comtian metaphysical state as both a progressive and self-destructive transformation of “theology”, using an example drawn from the history of astronomy (Longomontanus). The broader relevance of this conception is then assessed in the field of social philosophy, so that (...) the realm of natural sciences is finally re-examined with the analysis of Comte’s criticisms of the theory of chemical affinity (Berthollet). (shrink)

The purpose of my study is to reconstruct the historical development of Kant's pre- critical approach to mechanical explanation and cosmology. I shall focus on three main works: the 1755 Theorie des Himmels, the 1763 Beweisgrund and the 1766 Träume. I shall challenge some interpretations of the relation between mechanism and finalism, looking for the emergence of a principle of demarcation separating both ontologically and epistemologically organics from inorganics products. I shall try to show why Kant came to be dissatisfied (...) with his early systematic account of the formation and arrangement of the heavenly bodies on purely mechanical principles. Finally I shall argue that the pre-critical period ends, paving the way to a revision of cosmology in the light of an appreciation of the role of chemical affinity for the construction of the world-edifice. (shrink)

Classical thermochemistry is inextricably bound up with the problem of chemical affinity. In 1851, when Julius Thomsen began his career in thermochemistry, the concept of chemical affinity had been in the centre of chemical enquiry for more than a century. In spite of many suggestions, preferably to explain affinity in terms of electrical or gravitational forces, almost nothing was known about the cause and nature of affinity. In this state of puzzling uncertainty some chemists felt it more (...) advantageous to establish an adequate experimental measure of affinity, whatever its nature was. One way of providing affinity with a quantitative description was by means of the heats evolved in chemical processes. (shrink)

This article discusses some continuous limit cases of Susan Haack’s crossword puzzle metaphor for the coherent development and foundation of science. The main objective of this discussion is to build a bridge between Haack’s foundherentism and the epistemological framework of objective cognitive constructivism, including its key metaphor of objects as tokens for eigen-solutions. The historical development of chemical affinity tables is used to illustrate our arguments.

In this paper I sketch William Whewell’s attempts to impose order on classificatory mineralogy, which was in Whewell’s day (1794e1866) a confused science of uncertain prospects. Whewell argued that progress was impeded by the crude reductionist assumption that all macroproperties of crystals could be straightforwardly explained by reference to the crystals’ chemical constituents. By comparison with biological classification, Whewell proposed methodological reforms that he claimed would lead to a natural classification of minerals, which in turn would support advances in (...) causal understanding of the properties of minerals. Whewell’s comparison to successful biological classification is particularly striking given that classificatory biologists did not share an understanding of the causal structure underlying the natural classification of life (the common descent with modification of all organisms). Whewell’s key proposed methodological reform is consideration of multiple, distinct principles of classification. The most powerful evidence in support of a natural classificatory claim is the consilience of claims arrived at through distinct lines of reasoning, rooted in distinct conceptual approaches to the target objects. Mineralogists must consider not only elemental composition and chemical affinities, but also symmetry and polarity. Geometrical properties are central to what makes an individual mineral the type of mineral that it is. In Whewell’s view, function and organization jointly define life, and so are the keys to understanding what makes an organism the type of organism that it is. I explain the relationship between Whewell’s teleological account of life and his natural theology. I conclude with brief comments about the importance of Whewell’s classificatory theory for the further development of his philosophy of science and in particular his account of consilience. (shrink)

There are currently three major theories on the origin and evolution of the genetic code: the stereochemical theory, the coevolution theory, and the error-minimization theory. The first two assume that the genetic code originated respectively from chemical affinities and from metabolic relationships between codons and amino acids. The error-minimization theory maintains that in primitive systems the apparatus of protein synthesis was extremely prone to errors, and postulates that the genetic code evolved in order to minimize the deleterious effects (...) of the translation errors. This article describes a fourth theory which starts from the hypothesis that the ancestral genetic code was ambiguous and proposes that its evolution took place with a mechanism that systematically reduced its ambiguity and eventually removed it altogether. This proposal is distinct from the stereochemical and the coevolution theories because they do not contemplate any ambiguity in the genetic code, and it is distinct from the error-minimization theory because ambiguity-reduction is fundamentally different from error-minimization. The concept of ambiguity-reduction has been repeatedly mentioned in the scientific literature, but so far it has remained only an abstract possibility because no model has been proposed for its mechanism. Such a model is described in the present article and may be the first step in a new approach to the study of the evolution of the genetic code. (shrink)

Long after its alleged demise, phlogiston was still presented, discussed and defended by leading chemists. Even some of the leading proponents of the new chemistry admitted its ‘absolute existence’. We demonstrate that what was defended under the title ‘phlogiston’ was no longer a particular hypothesis about combustion and respiration. Rather, it was a set of ontological and epistemological assumptions and the empirical practices associated with them. Lavoisier's gravimetric reduction, in the eyes of the phlogistians, annihilated the autonomy of chemistry together (...) with its peculiar concepts of chemical substance and quality, chemical process and chemical affinity. The defence of phlogiston was the defence of a distinctly chemical conception of matter and its appearances, a conception which reflected the chemist's acquaintance with details and particularities of substances, properties and processes and his skills of adducing causal relations from the interplay between their complexity and uniformity. (shrink)

Summary The first systematic studies on the velocity of chemical reactions (now called reaction rates) were published in the 1850s and 1860s. Inquiring about the course of chemical change, their authors established empirical equations on the basis of their measurement results. But these laws, which represented reaction velocities as proportional to the actual concentration of the reagents, could not be given a physical foundation. The chemists themselves regarded their propositions as mere ad hoc hypotheses. In 1867 Leopold Pfaundler (...) formulated a qualitative theory of chemical processes based on Clausius's version of the kinetic gas theory (and more specifically on his theory of evaporation), and on Saint-Claire Deville's investigations of dissociation processes. Pfaundler's theory was based on farreaching analogies: between evaporation and dissociation; between the gaseous state and the activated state; and between evaporation- and chemical-equilibrium. Four points of Pfaundler's theory must be regarded as essential: (1) the reduction of chemical change to randomly occurring molecular collisions, only showing regularities in great numbers according to the laws of probability; (2) the idea that molecules are in different states of internal and external motion, which determines whether a collision results in a reaction; (3) the view of the reaction step as a transition from internal to external motion and vice versa; and (4) the introduction of a new molecular-kinetic definition of chemical affinity as the maximum of internal motion. With these assumptions, Pfaundler provided the empirical rate equations with a new statistical interpretation and a physical Justification. (shrink)

Ostwald (born September 2, 1853, Riga, Latvia, Russia; died April 4, 1932, at his private estate near Leipzig, Germany) almost single-handedly established physical chemistry as an acknowledged academic discipline. In 1909, he was awarded the Nobel Prize in chemistry for his work on catalysis, chemical equilibria, and reaction velocities. Ostwald was graduated in chemistry at the University of Dorpat (now Tartu, Estonia) and appointed professor of chemistry in Riga in 1881, before he moved from Russia to Germany on the (...) chair in physical chemistry at the University of Leipzig in 1887. For about twenty years he made Leipzig an international center of physical chemistry: by establishing an instruction and research laboratory that attracted virtually the whole next generation of physical chemists; by editing the first journal of the field (Zeitschrift für physikalische Chemie); and by writing numerous textbooks. In 1906, he retired from university and devoted the rest of his life to various topics, including the history and philosophy of science, color theory, painting, the writing of textbooks and popular books about science, the international organization of science, and the formation of an artificial language for the international exchange of ideas. Since his master degree thesis in 1876, Ostwald followed the general approach of applying physical measurement and mathematical reasoning to chemical issues. One of his major research topics was the chemical affinity of acids and bases. To that end, he studied the point of equilibrium in reactions systems where two acids in aqueous solution compete with each other for reaction with one base and vice versa. Because chemical analysis would have changed the equilibria, he skillfully adapted the measurement of physical properties to that problem, such as volume, refractive index, and electrical conductivity. From his extensive data he derived for each acid and base a characteristic affinity coefficient independent of the particular acid-base reactions. To understand the different chemical affinities, Ostwald drew on a new, but then hardly accepted and not yet fully developed, theory advanced by Svante Arrhenius. According to this theory of electrolytic dissociation, electrolytes like acids, bases, and salts dissociate in solution into oppositely charged ions to a certain degree, such that at infinite solution dissociation is complete.. (shrink)

Classical atoms—“part-less, ontologically irreducible simples” as the conference flyer puts it—are not the atoms of modern chemistry and analogies with the latter can be construed in various ways. They have figured in the historical development of concepts of chemical affinity but without, as Alan Chalmers and I have independently argued, making any significant contribution to empirically justified theories. A purely combinatorial conception of the formation of compounds by juxtaposing atoms is associated with Daltonian atomism. I review the merits of (...) this idea as a solution to problems posed by developments in early nineteenth century chemistry and go on to suggest that subsequent developments in chemistry are as much in agreement with ideas associated with Aristotle as with the ancient atomists, if not more so. The basic issues can be understood without getting involved in detailed chemistry and I hope what I have to say will be of interest to philosophers concerned with the metaphysics of matter but with no special knowledge of chemistry. (shrink)

O objetivo deste artigo é investigar a concepção enciclopédica de revolução científica posta em prática pelo químico francês L.-B. Guyton de Morveau (1737-1816). Deslocando a análise do conhecimento químico das Luzes do programa traçado por Lavoisier (1743-1794), sugerimos uma concepção revolucionária republicana, proclamada como resultado do esforço de uma coletividade. Daremos destaque a três abordagens revolucionárias de Guyton de Morveau no âmbito da química. A primeira foi sua atuação no ensino dessa ciência, cuja pedagogia e métodos de ensino foram fundamentais (...) para sua imersão social. Além disso, entre 1770 e 1790, Guyton de Morveau teve desempenhos decisivos no seio da empresa enciclopédica e no seio da escola química francesa. (shrink)

Origin of a dissipative structure in a chemical dynamic system: occurs under the following constraints: 1) Affinity must be high. (The system must be far from equilibrium.); 2) There must be an auto-catalytic process; 3) A process that reduces the concentration of the auto-catalyst must operate; 4) The relevant parameters (rate constants, etc.) must lie in a range corresponding to a limit cycle trajectory. That is, there must be closure of the network of reaction such that a state sufficiently (...) close to the prior condition is achieved at the corresponding part of each oscillation. If these constraints continue to be met interactions of the system with the rest of the world are quite different in the presence of the dissipative structure than they would be in the absence of that self-organized coherence. Closure of a network of relationships which gives rise to a dissipative structure is a 'unit-determining' feature. The effects of the structure as a whole are the resultants of the effects of the components, but the concentrations of the components at any instant are effects of the closure of the limit cycle. This is an influence on components arising from what those components constitute --- downward causation. (shrink)

I argue in the paper that classical chemistry is a science predominantly concerned with material substances, both useful materials and pure chemical substances restricted to scientific laboratory studies. The central epistemological and methodological status of material substances corresponds with the material productivity of classical chemistry and its way of producing experimental traces. I further argue that chemist’s ‘pure substances’ have a history, conceptually and materially, and I follow their conceptual history from the Paracelsian concept of purity to the modern (...) concept of pure stoichiometric compounds. The history of the concept of ‘pure substances’ shows that modern chemists’ concept of purity abstracted from usefulness rather than being opposed to it. Thus modern chemists’ interest in pure chemical substances does not presuppose a concept of pure science. (shrink)

This work utilizes examples from chemical sciences to present fundamentals of dialectics and synergetics. The laws of dialectics remain appropriate at the level of atoms, at the level of molecules, at the level of the reactions, and at the level of ideas. The law of the unity and conflict of opposites is seen, for instance, in the relationships between the ionization energy and electron affinity of atoms, between the forward and back reactions, as well as in the differentiation and (...) integration between the various areas of chemistry. The law of the passage of quantitative changes into qualitative changes describes the transformation properties of the compounds when the number and arrangement of atoms in the molecule undergoes changes. According to this law, the development is accompanied by breaks and jumps. This paper suggests equations for the description of these relationships. The law of the negation of the negation is manifested in the Periodic Law, in the evolution of ideas about the mutual transformation of chemical elements, in the development the concept of triads of elements, etc. Small changes in the conventional Periodic Table on the basis of previously rejected versions allow reflecting secondary and additional periodicity. Synergetics, similarly to dialectics, is dedicated to the studies of general laws of evolution. Synergetics includes highly advanced and specified ideas of dialectics. The cornerstone of synergetics is the principles of self-organization and nonlinearity. Mathematical development of these concepts was substantially facilitated by considering oscillating chemical reactions as an example. These reactions are quite complex and therefore provide adequate models for self-organization. Oscillations may exist only upon execution of specific thermodynamic, mathematical, and chemical conditions. Mechanisms of several oscillatory reactions are briefly reviewed. The construction of novel biomimetic or smart materials based on oscillating reactions is described. (shrink)

Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffroy's affinity table, Lavoisier's (...) classification of substances and their relationships, Mendeleev's periodic table, Cayley's enumeration of alkanes, Sylvester's association of algebra and chemistry, and Wiener's relationship between molecular structure and boiling points. These examples show that mathematical chemistry has much more than a century of history. (shrink)

This paper examines the negative response to Dalton’s atomic symbols by situating them in the context of the normative eighteenth-century representational system of affinity tables. Aesthetic analysis of the affinity tables reveals them as schema embedded with a potent functionalist empiricism. In contrast, the aesthetics of Dalton's symbols is associated with hypothetico-deductivism and alchemical iconicism.

Throughout the history of the Western world, science has possessed an extraordinary amount of authority and prestige. And while its pedestal has been jostled by numerous evolutions and revolutions, science has always managed to maintain its stronghold as the knowing enterprise that explains how the natural world works: we treat such legendary scientists as Galileo, Newton, Darwin, and Einstein with admiration and reverence because they offer profound and sustaining insight into the meaning of the universe. In The Intelligibility of Nature (...) , Peter Dear considers how science as such has evolved and how it has marshaled itself to make sense of the world. His intellectual journey begins with a crucial observation: that the enterprise of science is, and has been, directed toward two distinct but frequently conflated ends—doing and knowing. The ancient Greeks developed this distinction of value between craft on the one hand and understanding on the other, and according to Dear, that distinction has survived to shape attitudes toward science ever since. Teasing out this tension between doing and knowing during key episodes in the history of science—mechanical philosophy and Newtonian gravitation, elective affinities and the chemical revolution, enlightened natural history and taxonomy, evolutionary biology, the dynamical theory of electromagnetism, and quantum theory—Dear reveals how the two principles became formalized into a single enterprise, science, that would be carried out by a new kind of person, the scientist. Finely nuanced and elegantly conceived, The Intelligibility of Nature will be essential reading for aficionados and historians of science alike. (shrink)

Introduction: the age of reflexion Part I. Romanticism: 1. Romanticism and the sciences David Knight 2. Schelling and the origins of his Naturphilosophie S. R. Morgan 3. Romantic philosophy and the organization of the disciplines: the founding of the Humboldt University of Berlin Elinor S. Shaffer 4. Historical consciousness in the German Romantic Naturforschung Dietrich Von Engelhardt 5. Theology and the sciences in the German Romantic period Frederick Gregory 6. Genius in Romantic natural philosophy Simon Shaffer Part II. Sciences of (...) the Organic: 7. Doctors contra clysters and feudalism: the consequences of a Romantic revolution Nelly Tsouyopoulos 8. Morphotypes and the historical-genetic method in Romantic biology Timothy Lenoir 9. ’Metaphorical mystifications’: the Romantic gestation of nature in British biology Evelleen Richards 10. Transcendental anatomy Philip F. Rehbock 11. Romantic thought and the origins of cell theory L. S. Jacyna 12. Alexander von Humbolt and the geography of vegetation Malcolm Nicholson Part III. Sciences of the Inorganic: 13. Goethe, colour, and the science of seeing Dennis L. Sepper 14. Johann Wilhelm Ritter: Romantic physics in Germany Walter D. Wetzels 15. The power and the glory: Humphrey Davy and Romanticism Christopher Lawrence 16. Oersted’s discovery of electromagnetism H. A. M. Snelders 17. Caves, fossils and the history of the earth Nicholas A. Rupke Part IV. Literature and the Sciences: 18. Goethe’s use of chemical theory in his Elective Affinities Jeremy Adler 19. Kleist’s bedlam: abnormal psychology and psychiatry in the works of Heinrich von Kleist Nigel Reeves 20. Coleridge and the sciences Trevor H. Levere 21. Nature’s book: the language of science in the American Renaissance David van Leer 22. The shattered whole: Georg Buchner and Naturphilosophie John Reddick. (shrink)

During the second half of the nineteenth century, electronegativity has been one of the most relevant chemical concepts to explain the relationships between chemical substances and their possible reactions. Specifically, EN is a property of the substances that allows them to attract external electrons in bonding situations. The problem arises because EN cannot be measured directly. Indeed, the only way to measure it is through different properties that do can be directly measured, for instance enthalpy, ionization energies or (...) electron affinities. What is particularly troubling about this case in quantum chemistry is that the different models used to describe and quantify EN are incompatible but, in a certain sense, equivalent because the same EN scale results in all of them. By analyzing Linus Pauling’s and Robert Mulliken’s models of EN, it will be argued that, if we remain cling to a traditional representative conception of models, we cannot understand the meaning of the information provided by those models. Indeed, if we do not want to adopt an instrumentalist point of view concerning chemical knowledge, we should reconsider by virtue of what a model represents the system, or, in other words, which the factors that determine the representative power of a model are. I will propose a new perspective that incorporates the role of experimental techniques in the very notion of representation; this perspective allows us to understand how supposedly incompatible models of the same target system can be both simultaneously representative. (shrink)

Dynamin is a GTPase that regulates late events in clathrin‐coated vesicle formation. Our current working model suggests that dynamin is targeted to coated pits in its unoccupied or GDP‐bound form, where it is initially distributed uniformly throughout the clathrin lattice. GTP/GDP exchange triggers its release from these sites and its assembly into short helices that encircle the necks of invaginated coated pits like a collar. GTP hydrolysis, which is required for vesicle detachment, presumably induces a concerted conformation change, tightening the (...) collar. Unlike most of its GTPase cousins that serve as molecular switches, dynamin has a low affinity for GTP, a very high intrinsic rate of GTP hydrolysis and functions as a homo‐oligomer. A concerted conformational change resulting from coordinated GTP hydrolysis by the dynamin oligomer might be sufficient to generate force. In this case, dynamin would be the first GTPase identified that acts as a structural protein with mechano‐chemical function. (shrink)

According to microessentialism, it is necessary to resort to microstructure in order to adequately characterise chemical substances such as water. But the thesis has never been properly supported by argument. Kripke and Putnam, who originally proposed the thesis, suggest that a so-called stereotypical characterisation is not possible, whereas one in terms of microstructure is. However, the sketchy outlines given of stereotypical descriptions hardly support the impossibility claim. On the other hand, what naturally stands in contrast to microscopic description is (...) description in macroscopic terms, and macroscopic characterisations of water are certainly possible. This suffices to counter the claim that microdescriptions are necessary. Whether it counters the impossibility claim depends on whether all macroscopic descriptions are stereotypical (stereotypical descriptions presumably being macroscopic). In so far as systematic import of “stereotypical” can be determined, it would seem not. But some macroscopic characterisations have definite affinity with everyday knowledge, which presumably stands in conflict with the spirit of the impossibility claim. Since what is characterised are properties expressed by predicates like “is water”, the necessity of identity has no bearing here, and matters of interpretation pose problems for claims to the effect that science fixes the extension of “water” as ordinarily understood. (shrink)

Electronegativity is a quantified, typical chemical concept, which correlates the ability of chemical species to attract electrons during their contact with other species with measurable quantities such as dissociation energies, dipole moments, ionic radii, ionization potentials, electron affinities and spectroscopic data. It is applied to the description and explanation of chemical polarity, reaction mechanisms, other concepts such as acidity and oxidation, the estimation of types of chemical compounds and periodicity. Although this concept is very successful (...) and widely used, and in spite of the fact that it is still subject to scientific investigations, neither a more than intuitive definition nor a generally accepted, logically clear and standardized quantification model has been developed. In the present work, electronegativity is presented and discussed with respect to its main conceptual and operational continuities and discontinuities. We try to analyze the epistemological status of electronegativity, conceived as a typical notion of chemical sciences. Under ‘epistemological status’ we subsume the issues of its reference, its historical persistence, and the relationship between its measurement and quantification. (shrink)

Electronegativity, described by Linus Pauling described as “The power of an atom in a molecule to attract electrons to itself” (Pauling in The nature of the chemical bond, 3rd edn, Cornell University Press, Ithaca, p 88, 1960), is used to predict bond polarity. There are dozens of methods for empirically quantifying electronegativity including: the original thermochemical technique (Pauling in J Am Chem Soc 54:3570–3582, 1932), numerical averaging of the ionisation potential and electron affinity (Mulliken in J Chem Phys 2:782–784, (...) 1934), effective nuclear charge and covalent radius analysis (Sanderson in J Chem Phys 23:2467, 1955) and the averaged successive ionisation energies of an element’s valence electrons (Martynov and Batsanov in Zhurnal Neorganicheskoi Khimii 5:3171–3175, 1980), etc. Indeed, there are such strong correlations between numerous atomic parameters—physical and chemical—that the term “electronegativity” integrates them into a single dimensionless number between 0.78 and 4.00 that can be used to predict/describe/model much of an element’s physical character and chemical behaviour. The design of the common and popular medium form of the periodic table is in large part determined by four quantum numbers and four associated rules. However, adding electronegativity completes the construction so that it displays the multi-parameter periodic law operating in two dimensions, down the groups and across the periods, with minimal ambiguity. (shrink)

Based upon the demarcation between Elementalism and Atomism Chemistry from the perspective of the long-term history of chemistry, the authors re-examine the Berthollet-Proust controversy on the three types of chemical compounds, pointing out that Berthollet proposed the law of indefinite proportions by deduction, while Proust proposed the law of definite proportions by induction. The controversy is beyond the framework of affinity chemistry and entail a synthesis of meta-chemical thinking and experiments. Proust’s discovery of the law of definite proportions (...) not only function as Bacon’s “instances of lamp” to invoke Dalton and other atomism chemists to envision atomism, but also served as a bridge linking the two meta-chemistries. John Dalton, the third choice, envisioned his atomism by abduction. The case study on “the Berthollet-Proust controversy and Dalton’s resolution” mandates a reinvestigation of the crucial role of the system of experiments and the evolution of chemistry according to the demarcation between the established branches of Elementalism and Atomism Chemistry. (shrink)

By setting out the grammar of event causality, as developed by Hume and Mackie, in contrast to the grammar of agent causality in the natural sciences, a kind of hybrid hierarchical format for chemical explanations is sketched. From this starting point the history of agentive concepts in chemistry is displayed as a progression from Newton’s ‘forces’, through the nineteenth century concepts of ‘affinity’ and ‘valency’ to recent theories of molecular binding in terms of the migration of electrons and protons (...) as powerful particulars. The final stage of this development is the rewriting of chemical theory in terms of energy. (shrink)

In the 1930s Warburg's spare prose and disciplined respect for the facts set the style for a new generation of biochemists who had not known the conceptual revolutions of earlier years. Led by Warburg, they rejected the excesses of the colloid school and the false starts of the teens and twenties. Talk of active structure virtually disappeared as chemists began to identify enzymes, coenzymes, vitamins, and hormones. In the gradual transformation of the Atmungsferment from an ironcolloid complex to a specific (...) haem-protein, the roots of Warburg's inspiration were readily forgotten-the richer and more varied intellectual currents of the early decades of biochemistry. Experimental cytology and pharmacology were important strands. Most of what Warburg was doing on narcosis from 1908 to 1912 was typical of this school. He was deeply influenced by Loeb and his theory of the fertilization membrane. In the period from 1900 to 1914 the ups and down of belief in Hofmeister's enzyme theory was an important trend which helped determine the style of biochemistry in later decades. Warburg's conception of the Atmungsferment was shaped by the general reaction c. 1910 against Buchner's optimistic view. Warburg's Heidelberg lecture was framed as an answer to Hofmeister's lecture of 1901 and turned out almost as an imitation or second edition of it. It was a style that was soon out of fashion. The affinity between the early concept of enzymes and the old concept idea of “living protein” should not be neglected in discussions of Warburg's distaste for “enzymology.” The colloid school is too easily dismissed as a mere impediment to the chemical triumphs of the 1930s. Warburg's Atmungsferment was obviously colored by the colloidal cast of biochemical thought in 1912. The Atmungsferment represented, in short, a hybrid transition from the romantic biochemistry of the period 1900–1925 to the mature, classical of the 1930s. It is fascinating precisely because it reflects, and refracts through a unique and powerful mind, the varied local traditions of the early history of modern biochemistry. (shrink)

Francis Bacon's reflections on atomism have generally been misunderstood because they have never been systematically studied in relation to the speculative chemical philosophy which he developed in the interval between about 1592 and his death in 1626. This philosophy, in many respects unknown to historians until quite recently, was the only body of positive science which Bacon ever accepted. The speculative philosophy was, on the whole, chemical and non-mechanical, and consequently not consistent with atomist doctrines. In fact, Bacon (...) never at any time accepted the principal atomist tenets. It is therefore necessary to explain why he was interested in atomism at all. Of the several reasons for his interest one is especially important—namely, his belief that the speculative and atomic philosophies had affinities. In particular, he believed that of all the ancient philosophies atomism alone approached the ideals associated with the key notion of ‘subtlety’—ideals represented in their highest form in the speculative philosophy. (shrink)

Mi Gyung Kim (2008) has challenged the historiographical assumption that phlogiston was the paradigmatic concept in eighteenth century chemistry. Her analysis of the operational, theoretical, and philosophical identities of phlogiston demonstrates how Stahlian phlogiston was appropriated into the burgeoning field of affinity theory. However, this new French conception of phlogiston was destabilized by the introduction of Boerhaave's thermometrics. By extending this story through 1790, I will show that British pneumatic chemists integrated new understandings of heat with an affinity based operational (...) definition of phlogiston and thereby stabilized the concept. What resulted was a new and very different phlogiston. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Matter and Spirit in the Age of Animal MagnetismEric G. WilsonDuring the Romantic period, writers on both sides of the Atlantic explored the sleepwalker as a merger of holiness and horror. Emerging when scientific thinkers for the first time were connecting spirit to electricity and magnetism, the somnambulist became to certain Romantics a disclosure of the difficulty of harmonizing unseen and seen, agency and necessity. This problem prominently arose (...) in Anton Mesmer's late eighteenth-century experiments in animal magnetism, in which the sleepwalker proved a paradox: an opaque revelation of transparent currents and an unconscious vehicle of sophisticated thought. Romantics such as Coleridge embraced the somnambulist as an embodiment of these troubles involved in relating motion and meaning. Coleridge and those who responded to him saw in the hypnotized human this sobering possibility: the invisible requires the visible to make itself manifest while the visible needs the invisible to become significant. 1 This is sublime and sinister: to elevate a material form to spiritual power is transcendence; to sink the boundless into a body is grotesque.Here I explore the philosophical implications of animal magnetism, the place of the sleepwalker in the history of ideas, and the role of the hypnotized human in Romantic writers, especially Coleridge. I also meditate on relationships between matter and spirit, machine and human, word and thing. Along the way, I place the history of ideas and the works of Romantic writers in mutually illuminating dialogues. The literary texts shed fresh light on philosophical problems while the ideas reveal hidden literary elements.The somnambulistic trance had been around long before Mesmer's magnetic sleeps. For centuries, shamans had used auto-hypnosis to sound [End Page 329] their souls and other-hypnosis to cure their tribe-members' ailments. However, somnambulism could not become a scientific phenomenon until Europeans in laboratories began to study electricity and magnetism. In the early modern period, Paracelsus argued that a vital fluid courses through the cosmos. The human being draws this flow like a magnet attracts force. When the body pulls to itself evil effluvia, it falls ill. To return patients to health, Paracelsus placed magnets on painful areas. He hoped to extract the unwanted current and return it to the cosmic swirl. 2 In "magnetizing" spirit, Paracelsus opened a door for empirical inquiry into the invisible world. In 1600, William Gilbert claimed that magnets correspond to the earth: both are animated by universal attraction and repulsion. 3 By the end of the seventeenth-century, Newton proposed that things are impelled by a force that draws and repels. Newton's theory of gravity inspired natural philosophers of the next centuries to search for a principle of which the magnet and the spark are manifestations. 4During the second half of the eighteenth century and the early part of the nineteenth, natural philosophers explored electricity and magnetism with unprecedented precision. In 1752, Benjamin Franklin revealed the mystery of lightning and perhaps the spark of life. 5 Inspired by Franklin, F. C. Oetinger, J. L. Fricker, and Prokop Divisch developed a theology of electricity, based on the belief that God is the electrical current. 6 Later in the century, Luigi Galvani and Alessandro Volta debated over whether the galvanic flow might be the origin and principle of life itself. 7 A few years before Franklin harvested lightning, John Michell argued that the magnetic force is not constrained to lodestones but is possibly pervasive. Some years later, Franz Aepinus suggested that magnetism and electricity manifest a deep energy. Soon after, C. A. de Coulomb discovered the mathematical law by which electrical and magnetic forces operate (Whittaker, pp. 50–59).These findings led to the breakthroughs of the nineteenth century. 8 In 1807, Humphry Davy hypothesized that chemical elements interact through electromagnetic affinity or repulsion. 9 In 1820, H. C. Oersted demonstrated the correspondence between electricity and magnetism. The same year, A. M. Ampere formulated the laws by which electrical and magnetic currents interact (Whittaker, pp. 81–86). Michael Faraday in 1831 revealed electromagnetic induction and thus inaugurated a second Copernican revolution: he showed that matter is not solid and discrete but a field of electromagnetic energy. 10 The dreams of [End... (shrink)