The following investigation illustrates, by concrete historical examples, some of the basic results, outlined in earlier papers on theory evolution and reference dynamics in science (cf. Balzer, W. et al.: 1989, 'A Static Theory of Reference in Science', Synthese 79, 319-360; Lauth, B.: 1989, 'Reference Problems in Stoichiometry', Erkenntnis 30, 339-362; Lauth, B.: 1990, 'Theory Evolution and Reference Kinematics', Synthese 88, 279-307). All theories considered in this paper are represented within a metatheoretical frame that has become known as the (...) structuralist view in the philosophy of science. The paper focusses on some physical constants, namely the mass and charge of electrons, henceforth denoted by m₀ and e₀, of Boltzmann's constant k, Faraday's constant F and Avogadro's Number ${\rm N}_{{\rm A}}$ , and the evolution of their 'reference spectra' from the beginning of the 19th century until the early days of quantum physics. (shrink)

Philosophers frequently cite Dalton's chemical atomism, and its nineteenth century developments, as a prime example of inference to the best explanation. This was a controversial issue in its time. But the critics are dismissed as positivist‐inspired antirealists with no interest in explanation. Is this a reasonable assessment?

The world is an untidy place, and the sciences—all of them—reflect this. One source of this untidiness is the relationship between levels of organization. Reducing macrolevels to microlevels—explaining the former in terms of the latter—has met with successes but has never been the whole story. In the biological sciences, there has been much attention lately to the shortcomings of reductionism on the grounds that (i) it changes the subject rather than explaining, (ii) it leads to a myopically molecular view of (...) the biological world, and (iii) the behavior or behaviors of complex systems are often very poorly predicted based solely on their microproperties. It is just for these reasons that biologists of many stripes have called for a move away from reductionism and toward a new kind of biology for the 21st century. But what shape might this new biology take? (shrink)

(1974). Newton, Gases, and Daltonian chemistry: The foundations of combination in definite proportion. Annals of Science: Vol. 31, No. 6, pp. 561-574.

The concept of extent of reaction was discussed many times in physical chemistry journals and books. This contribution strongly suggests the use of the extent of reaction as standard basic tool in teaching stoichiometry. The same idea was suggested several times in the past without success because the concept of extent of reaction is still not presented in the first-year general chemistry textbooks. It is also remarked that the concept of extent of reaction represents a simple example of the (...) way of attaining a mathematization of chemistry, that is chemistry thought and made with the mathematical way of thinking, i.e. using variables, symbols and functions. Presenting the concept of the extent of reaction within the general chemistry curriculum will support successive physical chemistry courses, as these courses make extensive use of this powerful concept when teaching thermodynamics and kinetics of chemical reactions. (shrink)

This article serves as an introduction to the laws-of-biology debate. After introducing the main issues in an introductory section, arguments for and against laws of biology are canvassed in Section 2. In Section 3, the debate is placed in wider epistemological context by engaging a group of scholars who have shifted the focus away from the question of whether there are laws of biology and toward offering good accounts of explanation(s) in the biological sciences. Section 4 introduces two relatively new (...) pieces of science – metabolic scaling theory and ecological stoichiometry – that have not been topics of much discussion by philosophers but are relevant because they have at least some of the hallmarks of laws of nature. Section 5 concludes by pointing out that discovering laws of biology, if any there be, will not necessarily answer the questions raised by the debate in the first place: we will still want to know how biology compares to other sciences, how to characterize its systems and processes, and whether accounts in terms of laws always or usually constitute adequate explanations in various sciences. (shrink)

The chemist Jeremias Benjamin Richter (1762–1807) coined the term “stoichiometry” and proposed the “law of definite proportions.” He is also commonly acknowledged as having been a student of Immanuel Kant (1724–1804). This paper demonstrates how Kant’s philosophy positively shaped Richter’s approach to chemistry in the _Anfangsgründe der Stöchiometrie_ (1792–1794) and outlines two ways in which Richter attempted to represent the chemical force in “pure intuition”: (1) “reductionistic forces,” in which qualitative features scale with the quantity of matter; and (2) (...) generalized “abstracted forces,” in which a plurality of dissolution- and bonding-properties are latent within the chemical in the manifold of space-time. (shrink)

It is a notion commonly acknowledged that in his work Timaeus the Athenian philosopher Plato (_c_. 429–347 BC) laid down an early chemical theory of the creation, structure and phenomena of the universe. There is much truth in this acknowledgement because Plato’s “chemistry” gives a description of the material world in mathematical terms, an approach that marks an outstanding advancement over cosmologic doctrines put forward by his predecessors, and which was very influential on western culture for many centuries. In the (...) present article, I discuss inter-transformations among Plato’s four types (fire, air, water, and earth) as well as the interpretation they received in the literature. I find that scientists and scholars generally emphasized (and often misunderstood) mathematical aspects of these “reactions” over the philosophical ones. I argue that Plato’s “chemistry” in fact bears on crucial topics of his philosophical system, such as Forms, Becoming, causation and teleology. I propose that consideration of these doctrines help to understand not only the sense of his “chemical” reactions, but also the reason why their stoichiometry is by surface balance and is restricted only to types that come to be and pass away but not to those that provoke the inter-transformations. (shrink)

Scientists typically do something other than accept or reject their theories, they pursue them. Throughout the greater part of the nineteenth century numerous chemists devoted their research energy and resources to the development of Daltonian theory, declaring themselves willing to make use of the atomic theory in their research but reluctant or unwilling to accept it. When Frankland, for example, declared that he did not want to be considered a “blind believer” in the atomic theory and could not “accept (...) it as true”, but that he had been—and planned to continue—using it “as a useful ladder”, he had arrived at a decision shared by many of his colleagues that while the theory was not acceptable, it was promising and worthy of pursuit.1 And when Van’t Hoff measured the kinetic-molecular theory by its fruits in the 1880’s, he judged that it barely gave the then-current 4% interest rate, and so was an unpromising theory, unworthy of pursuit (van Nelsen 1960. p. 151). (shrink)

The near-interface region of an epitaxial Ba 0.3 Sr 0.7 TiO 3 thin film grown on LaAlO 3 was found to consist of a high density of stacking faults bounded by partial dislocations. The stacking faults can extend over large distances . Various possible atomic configurations of the faults were considered. The atomic structures of the faults were identified using high-resolution electron microscopy and simulation as well as energy-filtered imaging. The and faults were found to lie predominately on the {100} (...) and {110} planes. The faults on , or have never been observed before in perovskites. The stacking faults on {100} have a structure consisting of a double layer of edge-sharing TiO 6 octahedra. The excess of Ti was detected by energy-filtered imaging. The formation of the extended stacking faults is probably related to a small amount of excess Ti during the film deposition, which may originate from the non-stoichiometry of the ceramic targets BaTiO 3 and SrTiO 3 . It is also enhanced by the misfit-induced compressive strain in the early stages of the film growth. (shrink)

This article presents a simple derivation of optimization models for reaction networks leading to a generalized form of the mass-action law, and compares the formal structure of Minimum Information Divergence, Quadratic Programming and Kirchhoff type network models. These optimization models are used in related articles to develop and illustrate the operation of ontology alignment algorithms and to discuss closely connected issues concerning the epistemological and statistical significance of sharp or precise hypotheses in empirical science.

We argue for an account of chemical reactivities as chancy propensities, in accordance with the ‘complex nexus of chance’ defended by one of us in the past (Suárez, 2017, 2020). Reactivities are typically quantified as proportions, and an expression such as “A + B → C” does not entail that under the right conditions some amounts of A and B react to give the amount of C that theoretically would correspond to the stoichiometry of the reaction. Instead, what is (...) produced is a fraction α < 1 of this theoretical amount, and the corresponding percentage is usually known as the yield, which expresses the relative preponderance of its reaction. This is then routinely tested in a laboratory against the observed actual yields for the different reactions. Thus, on our account, reactivities ambiguously refer to three quantities at once. They first refer to the underlying propensities effectively acting in the reaction mechanisms, and which in ‘chemical chemistry’ (Schummer, 1998) are commonly represented by means of Lewis structures. Besides, reactivities represent the probabilities that these propensities give rise to, for any amount of the reactants to combine as prescribed. This last notion is hence best understood as a single case chance and corresponds to a theoretical stoichiometric yield. Finally, reactivities represent the actual yields observed in experimental runs, which account for and provide the requisite evidence for / against both the mechanisms and single case chances ascribed. (shrink)

We argue for an account of chemical reactivities as chancy propensities, in accordance with the ‘complex nexus of chance’ defended by one of us in the past. Reactivities are typically quantified as proportions, and an expression such as “A + B → C” does not entail that under the right conditions some given amounts of A and B react to give the mass of C that theoretically corresponds to the stoichiometry of the reaction. Instead, what is produced is a (...) fraction α < 1 of this theoretical amount, and the corresponding percentage is usually known as the yield, which expresses the relative preponderance of its reaction. This is then routinely tested in a laboratory against the observed actual yields for the different reactions. Thus, on our account, reactivities ambiguously refer to three quantities at once. They first refer to the underlying propensities effectively acting in the reaction mechanisms, which in ‘chemical chemistry’ (Schummer in Hyle 4:129–162, 1998) are commonly represented by means of Lewis structures. Besides, reactivities represent the probabilities that these propensities give rise to, for any amount of the reactants to combine as prescribed. This last notion is hence best understood as a single case chance and corresponds to a theoretical stoichiometric yield. Finally, reactivities represent the actual yields observed in experimental runs, which account for and provide the requisite evidence for/against both the mechanisms and single case chances ascribed. (shrink)

Metallothioneins (MTs) are ubiquitous proteins with the capacity to bind heavy metal ions (mainly Cd, Zn or Cu), and they have been found in animals, plants, eukaryotic and prokaryotic micro‐organisms. We have carried out a comparative analysis of ciliate MTs (Tetrahymena species) to well‐known MTs from other organisms, discussing their exclusive features, such as the presence of aromatic amino acid residues and almost exclusive cysteine clusters (CCC) present in cadmium‐binding metallothioneins (CdMTs), higher heavy metal‐MT stoichiometry values, and a strictly (...) conserved modular–submodular structure. Based on this last feature and an extensive gene duplication, we propose a possible model for the evolutionary history of T. thermophila MTs. We also suggest possible functions for these MTs from consideration of their differential gene expressions and discuss the potential use of these proteins and/or their gene promoters for designing molecular or whole‐cell biosensors for a fast detection of heavy metals in diverse polluted ecosystems. (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)

Abstract.This article takes on a perhaps impossible task: not only to reconstruct the core argument of Arthur Peacocke's program in science and religion but also to evaluate it in two major areas where it would seem to be vulnerable, namely, more recent developments in systems biology and the philosophy of mind. If his theory of hierarchies is to be successful, it must stand up to developments in these two areas and then be able to apply the results in a productive (...) way to Christian theological reflection. Peacocke recognized that one's model of the mind‐body relation is crucial for one's position on the God‐world relation and divine action. Of the three models that he constructed, it turns out that only the third can serve as a viable model for theology if it is to be more than purely deistic or metaphorical. (shrink)

Eukaryotic mRNAs are monocistronic, and therefore mechanisms exist that coordinate the synthesis of multiprotein complexes in order to obtain proper stoichiometry at the appropriate intracellular locations. RNA‐binding proteins containing low‐complexity sequences are prone to generate liquid droplets via liquid‐liquid phase separation, and in this way create cytoplasmic assemblages of functionally related mRNAs. In a recent iCLIP study, we showed that the Drosophila RNA‐binding protein Imp, which exhibits a C‐terminal low‐complexity sequence, increases the formation of F‐actin by binding to 3′ (...) untranslated regions of mRNAs encoding components participating in F‐actin biogenesis. We hypothesize that phase transition is a mechanism the cell employs to increase the local mRNA concentration considerably, and in this way synchronize protein production in cytoplasmic territories, as discussed in the present review. (shrink)