Chemical Elements and Substances

The potential reducibility of chemical entities to their physical bases is a matter of dispute between ontological reductionists on one hand, and emergentists on the other. However, relevant debates typically revolve around the reducibility of so-called ‘higher-level’ chemical entities, such as molecules. Perhaps surprisingly, even committed proponents of emergence for these higher-level chemical entities appear to accept that the ‘lowest-level’ chemical entities – atomic species – are reducible to their physical bases. In particular, the microstructural view of chemical elements, actively (...) developed and defended by emergentists, appears to hold that the explanatory power of nuclear charge justifies being reductionist about atomic species. My first task in this paper is to establish that nuclear charge cannot ultimately provide explanations sufficient to justify a reductionist approach to atomic species, unless we abandon the persuasive intuition that the presence of an element in a substance ought to explain the properties of that substance. The ‘missing piece’ for explaining the properties of substances by way of their elemental constituents is the electronegativity values of participant atoms. But electronegativity is a strikingly disunified concept that appears distinctly unamenable to analysis by way of fundamental physical principles. Through evaluating the uncertain physical identity of electronegativity, as well as its widespread and indispensable epistemic utility in chemical practice, I argue that electronegativity provides compelling grounds to seriously consider emergence for atomic species. (shrink)

The heated debates and severe conflicts between the atomists and the anti-atomists of the latter half of the nineteenth century are well known to the historian of science. The position of Dmitrii Ivanovich Mendeleev towards these nineteenth century debates on atomism will be studied in this paper. A first attempt will thus be offered to reconcile Mendeleev’s seemingly contradictory comments and ambiguous standpoints into one coherent view.

It is widely recognized that conceptual and theoretical innovations and the employment of new instruments and experimental techniques are important factors in explaining the growth of scientific knowledge in chemistry. This study examines another dimension of research in chemistry, collaboration and co-authorship. I focus specifically on Theodore Richards’ career and publications. During the period in which Richards worked, co-authorship was beginning to become more common than it had been previously. Richards was the first American chemist to be awarded a Nobel (...) Prize and he was at the forefront in this new trend in chemistry. He collaborated more than was typical for his time, with many scientists, in different sized groups, and he often had persistent collaborative relationships, extending over a number of years. Further, it appears that these collaborations benefited Richards, his collaborators, and the field of chemistry as a whole. (shrink)

The philosophical vision of the world and the consequent methodology behind the book are clarified. The perspective used is the systemic one, but since today this term has assumed a wide and diversified meaning in the literature, this introduction will clarify the specific meaning of our approach, starting from the meaning of the term "system". Our idea of system is based on three key assertions that may seem contradictory, but are necessary and complementary to its definition. In particular, we considered (...) the usual idea that the system is more and less than the sum of its juxtaposed parts, highlighting the role of emergencies and constraints. In our idea of a system, however, we must consider a third fundamental characteristic: its dynamism, the dual nature of the system as an entity and as a process, its role as a "dynamic entity". Afterwards, the holistic and reductionist approaches were analysed in detail, and both the specific merits and the fact that these two opposing worldviews, considered individually, cannot give a complete and balanced description of reality, were taken into account. For us, only the systemic approach provides a balanced description of both the parts and the whole and must, therefore, be preferred. Finally, the differences between our approach and the approaches mentioned above have been considered in detail in this introduction. (shrink)

We provide a detailed history of the concepts of atomic number and isotopy before the discovery of protons and neutrons that draws attention to the role of evolving interplays of multiple aims and criteria in chemical and physical research. Focusing on research by Frederick Soddy and Ernest Rutherford, we show that, in the context of differentiating disciplinary projects, the adoption of a complex and shifting concept of elemental identity and the ordering role of the periodic table led to a relatively (...) coherent notion of atomic number. Subsequent attention to valency, still neglected in the secondary literature, and to nuclear charge led to a decoupling of the concepts of elemental identity and weight and allowed for a coherent concept of isotopy. This concept received motivation from empirical investigations on the decomposition series of radioelements and their unstable chemical identity. A new model of chemical order was the result of an ongoing collaboration between chemical and physical research projects with evolving aims and standards. After key concepts were considered resolved and their territories were clarified, chemistry and physics resumed autonomous projects, yet remained bound by newly accepted explanatory relations. It is an episode of scientific collaboration and partial integration without simple, wholesale gestalt switches or chemical revolutions. (shrink)

Compared to its sister disciplines—philosophy of physics and philosophy of biology—philosophy of chemistry remains a relatively young field of philosophical endeavour. Having originated in the late...

I challenge Gareth Eaton’s recent claim that Theodore Richards should be counted among the discoverers of isotopes. In evaluating Eaton’s claim, I draw on two influential theories of scientific discovery, one developed by Thomas Kuhn, and one developed by Augustine Brannigan. I argue that though Richards’ experimental work contributed to the discovery, his work does not warrant attributing the discovery to him. Richards’ reluctance to acknowledge isotopes is well documented. Further, the fact that he made no claim to having made (...) the discovery also undermines Eaton’s argument. (shrink)

I respond to Scerri’s recent reply to my claim that there was a scientific revolution in chemistry in the early twentieth Century. I grant, as Scerri insists, that there are significant continuities through the change about which we are arguing. That is so in all scientific revolutions. But I argue that the changes were such that they constitute a Kuhnian revolution, not in the classic sense of The Structure of Scientific Revolutions, but in the sense of Kuhn’s mature theory, developed (...) in the 1980s and early 1990s. (shrink)

This chapter examines the work in chemistry that led to the discovery of boron and explores the implications of this episode for the scientific realism debate. This episode begins with Lavoisier’s oxygen theory of acidity and his prediction that boracic acid contains oxygen and a hypothetical, combustible substance that he called the boracic radical. And it culminates in the work of Davy, Gay-Lussac, and Thénard, who used potassium to extract oxygen from boracic acid and thereby discovered boron. This episode constitutes (...) a novel predictive success of Lavoisier’s theory of acidity, which was not even approximately true. Selective realists attempt to accommodate such false-but-successful theories by showing that their success is due to the fact that they have approximately true parts. This episode poses a strong challenge to selective realism because the parts of Lavoisier’s theory that are responsible for its success are not even approximately true. (shrink)

The thesis is: the “periodic table” of “dark matter” is equivalent to the standard periodic table of the visible matter being entangled. Thus, it is to consist of all possible entangled states of the atoms of chemical elements as quantum systems. In other words, an atom of any chemical element and as a quantum system, i.e. as a wave function, should be represented as a non-orthogonal in general (i.e. entangled) subspace of the separable complex Hilbert space relevant to the system (...) to which the atom at issue is related as a true part of it. The paper follows previous publications of mine stating that “dark matter” and “dark energy” are projections of arbitrarily entangled states on the cognitive “screen” of Einstein’s “Mach’s principle” in general relativity postulating that gravitational field can be generated only by mass or energy. (shrink)

This paper investigates the case of enzyme classification to evaluate different ideals for regulating values in science. I show that epistemic and non-epistemic considerations are inevitably and untraceably entangled in enzyme classification, and argue that this has significant implications for the two main kinds of views on values in science, namely, Epistemic Priority Views and Joint Satisfaction Views. More precisely, I argue that the case of enzyme classification poses a problem for the usability and descriptive accuracy of these two views. (...) The paper ends by suggesting that these two views provide different but complementary perspectives, and that both are useful for evaluating values in science. (shrink)

Arthur Clark and Michael Kube–McDowell (“The Triger”, 2000) suggested the sci-fi idea about the direct transformation from a chemical substance to another by the action of a newly physical, “Trigger” field. Karl Brohier, a Nobel Prize winner, who is a dramatic persona in the novel, elaborates a new theory, re-reading and re-writing Pauling’s “The Nature of the Chemical Bond”; according to Brohier: “Information organizes and differentiates energy. It regularizes and stabilizes matter. Information propagates through matter-energy and mediates the interactions of (...) matter-energy.” Dr Horton, his collaborator in the novel replies: “If the universe consists of energy and information, then the Trigger somehow alters the information envelope of certain substances –“. “Alters it, scrambles it, overwhelms it, destabilizes it” Brohier adds. There is a scientific debate whether or how far chemistry is fundamentally reducible to quantum mechanics. Nevertheless, the fact that many essential chemical properties and reactions are at least partly representable in terms of quantum mechanics is doubtless. For the quantum mechanics itself has been reformulated as a theory of a special kind of information, quantum information, chemistry might be in turn interpreted in the same terms. Wave function, the fundamental concept of quantum mechanics, can be equivalently defined as a series of qubits, eventually infinite. A qubit, being defined as the normed superposition of the two orthogonal subspaces of the complex Hilbert space, can be interpreted as a generalization of the standard bit of information as to infinite sets or series. All “forces” in the Standard model, which are furthermore essential for chemical transformations, are groups [U(1),SU(2),SU(3)] of the transformations of the complex Hilbert space and thus, of series of qubits. One can suggest that any chemical substances and changes are fundamentally representable as quantum information and its transformations. If entanglement is interpreted as a physical field, though any group above seems to be unattachable to it, it might be identified as the “Triger field”. It might cause a direct transformation of any chemical substance by from a remote distance. Is this possible in principle? (shrink)

To this day, a hundred and fifty years after Mendeleev's discovery, the overal structure of the periodic system remains unaccounted for in quantum-mechanical terms. Given this dire situation, a handful of scientists in the 1970s embarked on a quest for the symmetries that lie hidden in the periodic table. Their goal was to explain the table's structure in group-theoretical terms. We argue that this symmetry program required an important paradigm shift in the understanding of the nature of chemical elements. The (...) idea, in essence, consisted of treating the chemical elements, not as particles, but as states of a superparticle. We show that the inspiration for this came from elementary particle physics, and in particular from Heisenberg's suggestion to treat the proton and neutron as different states of the nucleon. We provide a careful study of Heisenberg's last paper on the nature of elementary particles, and explain why the Democritean picture of matter no longer applied in modern physics and a Platonic symmetry-based picture was called for instead. We show how Heisenberg's Platonic philosophy came to dominate the field of elementary particle physics, and how it found its culmination point in Gell-Mann's classification of the hadrons in the eightfold way. We argue that it was the success of Heisenberg's approach in elementary particle physics that sparked the group-theoretical approach to the periodic table. We explain how it was applied to the set of chemical elements via a critical examination of the work of the Russian mathematician Abram Ilyich Fet the Turkish-American physicist Asim Orhan Barut, before giving some final reflections. (shrink)

The success of a few theories in statistical thermodynamics can be correlated with their selectivity to reality. These are the theories of Boltzmann, Gibbs, end Einstein. The starting point is Carnot’s theory, which defines implicitly the general selection of reality relevant to thermodynamics. The three other theories share this selection, but specify it further in detail. Each of them separates a few main aspects within the scope of the implicit thermodynamic reality. Their success grounds on that selection. Those aspects can (...) be represented by corresponding oppositions. These are: macroscopic – microscopic; elements – states; relational – non-relational; and observable – theoretical. They can be interpreted as axes of independent qualities constituting a common qualitative reference frame shared by those theories. Each of them can be situated in this reference frame occupying a different place. This reference frame can be interpreted as an additional selection of reality within Carnot’s initial selection describable as macroscopic and both observable and theoretical. The deduced reference frame refers implicitly to many scientific theories independent of their subject therefore defining a general and common space or subspace for scientific theories (not for all). The immediate conclusion is: The examples of a few statistical thermodynamic theories demonstrate that the concept of “reality” is changed or generalized, or even exemplified (i.e. “de-generalized”) from a theory to another. Still a few more general suggestions referring the scientific realism debate can be added: One can admit that reality in scientific theories is some partially shared common qualitative space or subspace describable by relevant oppositions and rather independent of their subject quite different in general. Many or maybe all theories can be situated in that space of reality, which should develop adding new dimensions in it for still newer and newer theories. Its division of independent subspaces can represent the many-realities conception. The subject of a theory determines some relevant subspace of reality. This represents a selection within reality, relevant to the theory in question. The success of that theory correlates essentially with the selection within reality, relevant to its subject. (shrink)

In his account of scientific revolutions, Thomas Kuhn suggests that after a revolutionary change of theory, it is as if scientists are working in a different world. In this paper, we aim to show that the notion of world change is insightful. We contrast the reporting of the discovery of neon in 1898 with the discovery of hafnium in 1923. The one discovery was made when elements were identified by their atomic weight; the other discovery was made after scientists came (...) to classify elements by their atomic number. By considering two instances of the reporting of the discovery of a new chemical element 25 years apart, we argue that it becomes clear how chemists can be said to have been responding to different worlds as a result of the change in the concept of a chemical element. They saw, did, and reported different things as they conducted their research on the new chemical elements. (shrink)

ABSTRACT The idea that the extension of a chemical substance is fixed by determining what stands in the relation of being the same substance to a paradigm sample plays a substantial role in chemistry, and procedures of identification that don’t make direct use of the method can be traced back to ones that do. But paradigm samples are not typically selected by ostension, as in Putnam’s version of this procedure. The relevance of ostension is questioned after a discussion of the (...) establishment of paradigm specimens in the analysis of some contents of crude oil and an examination of the general features of the same-substance relation that takes into account the temporal dependency and the consequent role of characteristic features of substances. 1Introduction 2Some Formal Properties of the Same-Substance Relation 3Characteristic Properties and Paradigm Samples 4Naming Substances Old and New 5Some Points of Comparison with Temperature 6Summary and Conclusion. (shrink)

Aiming at the conflict between access and storage due to the continuous accumulation of knowledge storage in the field of artificial intelligence in welding, the author uses RDF (Resource Description Framework) to represent the technological knowledge of CO2 gas shielded welding, designs and implements a knowledge base based on Web semantic and stores it in HDFS, which is used to solve the difficulties of mass data storage. By studying the mechanism and characteristics of spatter in CO2 gas shielded welding, aiming (...) at the common measures and means of reducing spatter, the author realizes the inference function based on welding process rules by using Jena framework and optimizes the craft realization, finally integrates the core functions into the Spring framework and adopts the HTML5-based interface design to enable a new welding process expert system across the Internet and mobile platform. (shrink)

Invited review of the anthology of new papers _Philosophy of Chemistry: Growth of a New Discipline_.

Attempting to compare scientific theories requires a philosophical model of meaning. Yet different scientific theories have at times—particularly in early chemistry—pre-supposed disparate theories of meaning. When two theories of meaning are incommensurable, we must say that the scientific theories that rely upon them are meta-incommensurable. Meta- incommensurability is a more profound sceptical threat to science since, unlike first-order incommensurability, it implies complete incomparability.

In a number of papers and in his recent book, Is Water H₂O? Evidence, Realism, Pluralism (2012), Hasok Chang has argued that the correct interpretation of the Chemical Revolution provides a strong case for the view that progress in science is served by maintaining several incommensurable “systems of practice” in the same discipline, and concerning the same region of nature. This paper is a critical discussion of Chang's reading of the Chemical Revolution. It seeks to establish, first, that Chang's assessment (...) of Lavoisier's and Priestley's work and character follows the phlogistonists' “actors' sociology”; second, that Chang simplifies late-eighteenth-century chemical debates by reducing them to an alleged conflict between two systems of practice; third, that Chang's evidence for a slow transition from phlogistonist theory to oxygen theory is not strong; and fourth, that he is wrong to assume that chemists at the time did not have overwhelming good reasons to favour Lavoisier's over the phlogistonists' views. (shrink)

Recent work on Natural Kind Essentialism has taken a deflationary turn. The assumptions about the grounds of essentialist truths concerning natural kinds familiar from the Kripke-Putnam framework are now considered questionable. The source of the problem, however, has not been sufficiently explicated. The paper focuses on the Twin Earth scenario, and it will be demonstrated that the essentialist principle at its core (which I call IDENT)—that necessarily, a sample of a chemical substance, A, is of the same kind as another (...) sample, B, if and only if A and B have the same microstructure—must be re-evaluated. The Twin Earth scenario also assumes the falsity of another essentialist principle (which I call INST): necessarily, there is a 1:1 correlation between (all of ) the chemical properties of a chemical substance and the microstructure of that substance. This assumption will be questioned, and it will be argued that, in fact, the best strategy for defending IDENT is to establish INST. The prospects for Natural Kind Essentialism and microstructural essentialism regarding chemical substances will be assessed with reference to recent work in the philosophy of chemistry. Finally, a weakened form of INST will be presented. (shrink)

Friedrich Paneth’s conception of “chemical element” has functioned as the official definition adopted by the International Union of Pure and Applied Chemistry since 1923. Paneth maintains a distinction between empirical and “transcendental” concepts of element; furthermore, chemical science requires fluctuation between the two. The origin of the empirical-transcendental split is found in Immanuel Kant’s classic Critique of Pure Reason (1781/1787). The present paper examines Paneth’s foundational concept of element in light of Kant’s attempt, late in life, to revoke key distinctions (...) made in his Critique, including that of regulative and constitutive functions of reason. In a section of his Opus postumum devoted to the “Transition from the Metaphysical Foundations of Natural Science to Physics,” Kant bends his philosophical system to address the newly emerging sciences of matter of his time. Specifically, he tried, without success, to develop the transcendental ground for microscale motions of bodies encountered in physical, electrical and chemical processes. Paneth’s discussion of chemical element does not take the Opus postumum into account, which is why it begins with a rejection of Kant’s rejection (in his earlier writings) of chemistry’s status as science. I make the case that Paneth’s definition of element effectively maintains something very like Kant’s critical separation of regulative and constitutive principles, while a advancing the concept of chemical science. (shrink)

At the heart of chemistry lies the periodic system of chemical elements. Despite being the cornerstone of modern chemistry, the overall structure of the periodic system has never been fully understood from an atomic physics point of view. Group-theoretical models have been proposed instead, but they suffer from several limitations. Among others, the identification of the correct symmetry group and its decomposition into subgroups has remained a problem to this day. In an effort to deepen our limited understanding of the (...) periodic law, we have extended the traditional Lie algebraic framework to account for the peculiar degeneracy structure of the periodic system. Starting from the four-dimensional hidden symmetry and accidental degeneracy of the hydrogen atom, as first revealed by Fock in 1935, our research has mainly focussed on the way this SO(4) symmetry of the Coulomb potential gets broken in the periodic system as a consequence of the transformation of the hydrogenic (n, l) filling order to the Madelung (n+l, n) order due to electronic repulsions, relativistic effects and spin-orbit couplings. In this PhD dissertation, a new left-step format of the periodic table is first proposed on the basis of the Madelung rule. Following the particle physics tradition, the chemical elements are then considered as various states of some 'atomic matter', which is described by a non-compact spectrum-generating dynamical Lie group. The chemical elements are shown to form a basis for a single infinite-dimensional degeneracy space of the SO(4,2) ⊗ SU(2) group. An explanation for the period doubling is then proposed in terms of a particular symmetry breaking of the SO(4,2) group to the anti de Sitter SO(3,2) group. The Madelung rule is rationalised on the basis of nonlinear Lie algebras which reflect the screening of the Coulomb hole. This opens new perspectives for a symmetry-based understanding of how the periodic law emerges from its quantum mechanical foundations, and holds the future promise of complementing our current phenomenological approach by a direct atomic physics approach. (shrink)

Using the cases of three Russian chemistry textbooks from the 1860s—authored by Freidrich Beilstein, A. M. Butlerov, and D. I. Mendeleev—this essay analyzes their contemporary translation into German and the implications of their divergent histories for scholars' understanding of the processes of credit accrual and the choices of languages of science.

I criticize the treatment of natural kinds as some sort of object, advocated in a recent paper by Alexander Bird. The arguments he gives for regimenting an illustrative statement featuring chemical kinds in his preferred manner are not conclusive, and his criticisms of an alternative strategy involving universally quantified sentences fail. This is important because of the widespread but poorly supported assumption that expressions of natural kinds should be treated as singular referring terms.

Over the last two decades a new scholarship on alchemy has emerged, leading to a fundamental reformulation of knowledge about alchemists and their activities. We now know that medieval and early modern alchemists employed experiment in concert with theory to demonstrate the existence of stable “chymical atoms,” which were thought to combine with one another according to a hierarchical theory of matter. Employing laboratory-based analysis and synthesis, alchemists were among the first explicitly to enunciate the principle of mass balance and (...) to show that materials are compounded of the ingredients into which they can be physically decomposed. Perhaps even more surprisingly, these convictions and practices arose out of the interaction of alchemical practice with scholastic Aristotelianism, long viewed by historians of the Scientific Revolution as antithetical to experiment. Thus the new historiography challenges both a long-standing marginalization of alchemy itself and a commonplace view of Aristotelianism as inimical to the early modern growth of experimental science. -/- . (shrink)

In this essay I critically examine the role of entropy of mixing in articulating a macroscopic criterion for the sameness and difference of chemical substances. Consider three cases of mixing in which entropy change occurs: isotopic variants, spin isomers, and populations of atoms in different orthogonal quantum states. Using these cases I argue that entropy of mixing tracks differences between physical states, differences that may or may not correspond to a difference of substance. It does not provide a criterion for (...) the sameness and difference of substance that is appropriate to chemistry. (shrink)

A lively philosophical debate has lately arisen over the nature of elementhood in chemistry. Two different senses in which the technical term ELEMENT is currently in use by chemists have been identified, leaving chemistry open to the logical fallacy of equivocation. This paper introduces a third, more elemental candidate: the high-enthalpy short-lived unbonded atom. An enthalpy index based on free-atoms-as-elements is established, whereby one can monitor the degree to which an atom’s spin-based attractive force is implemented exo-enthalpically when the atom (...) binds chemically to others. Enthalpy indexing shows that the strength of an atom’s attractive force is proportional to its spin angular momentum. Vibrational spectroscopy shows that the force varies inversely as the fourth power of the inter-atom distance. Both features differentiate the chemical force from the stronger electromagnetic force and from the weaker Van der Waals force. (shrink)

Gibbs’s phase rule treats mixtures by relating the number of independent variables governing their state to the numbers of phases and independent substances. For the case of a single substance, it provides a criterion of purity. But where more substances are involved, the notion of independent substance is less readily understood. Textbook writers sometimes use algebraic terminology in ways that are suggestive but cannot be taken as literally accurate. I suggest that a mereological interpretation applies to these cases, as it (...) captures more concisely the insights underlying the use of algebraic ter- minology and illuminates the general notion of substance. (shrink)

There have been occasions when the publication of a particular book has had a singular impact on the conceptual world of the chemist. Sometimes the publication occurs near the beginning of a major change in discourse, and sometimes more near the end. Jean Perrin published Les Atomes in 1913 as the culmination of a century-long controversy over the size and physical reality of atoms and molecules. After its publication almost all chemists and physicists agreed that atoms and molecules of the (...) size we currently understand to be appropriate are real physical objects. The story of the background, development, publication, content and response to Les Atomes forms the text of this paper. The content of Les Atomes is also the basis for extended reflection on the philosophical significance of the work of Jean Perrin. (shrink)

In 1931 eminent chemist Fritz Paneth maintained that the modern notion of “element” is closely related to (and as “metaphysical” as) the concept of element used by the ancients (e.g., Aristotle). On that basis, the element chlorine (properly so-called) is not the elementary substance dichlorine, but rather chlorine as it is in carbon tetrachloride. The fact that pure chemicals are called “substances” in English (and closely related words are so used in other European languages) derives from philosophical compromises made by (...) grammarians in the late Roman Empire (particularly Priscian [fl. ~520 CE]). When the main features of the constitution of isotopes became clear in the first half of the twentieth century, the formal (IUPAC) definition of a “chemical element” was changed. The features that are “essential” to being an element had previously been “transcendental” (“beyond the sphere of consciousness”) but, by the mid-twentieth century the defining characteristics of elements, as such, had come to be understood in detail. This amounts to a shift in a “horizon of invisibility” brought about by progress in chemistry and related sciences. Similarly, chemical insight is relevant to currently-open philosophical problems, such as the status of “the bundle theory” of the coherence of properties in concrete individuals. (shrink)

While most chemists agree on what is a metal and what is a non-metal there is a disagreement with respect to what is a metalloid and what is a transition metal. It is believed that this problem can be solved if two new terms are adopted: typical and less typical metals. These new terms will also help reconcile the European Periodic Table versus the North American regarding numbering of groups as well as the IUPAC numbering which could be as well (...) abandoned in favour of group names as will be shown in the manuscript. (shrink)

Summary Apart from hydrogen, helium is the most abundant chemical element in the universe, and yet it was only discovered on the Earth in 1895. Its early history is unique because it encompasses astronomy as well as chemistry, two sciences which the spectroscope brought into contact during the second half of the nineteenth century. In the modest form of a yellow spectral line known as D3, ‘helium’ was sometimes supposed to exist in the Sun's atmosphere, an idea which is traditionally (...) ascribed to J. Norman Lockyer. Did Lockyer discover helium as a solar element? How was the suggestion received by chemists, physicists and astronomers in the period until the spring of 1895, when William Ramsay serendipitously found the gas in uranium minerals? The hypothetical element helium was fairly well known, yet Ramsay's discovery owed little or nothing to Lockyer's solar element. Indeed, for a brief while it was thought that the two elements might be different. The complex story of how helium became established as both a solar and terrestrial element involves precise observations as well as airy speculations. It is a story that is unique among the discovery histories of the chemical elements. (shrink)

Immanuel Kant has built up a dualistic epistemology that seems to fit to the peculiarities of chemistry quite well. Friedrich Paneth used Kant’s concept and characterised simple and basic substances which refer to the empirical and to the transcendental world, respectively. This paper takes account of the Kantian influences in Paneth’s philosophy of chemistry, and discusses pertinent topics, like observables, atomism and realism.

Since Mendeleev’s discovery in 1869, the periodic table has figured as the ultimate paper tool in chemical research. It has proved to be a vital research instrument in the arsenal of the chemical community. No chemistry textbook, lecture theatre or scientific laboratory is complete without a copy of the periodic table of the elements. -/- This however, should not necessarily imply that the periodic table has never had to contend with problems. In this thesis, the history of the accommodation of (...) the rare-earth elements in the periodic table will be addressed. When Mendeleev published his periodic table in 1869, the rare earths already constituted a major obstacle. Mendeleev was able to include only four members of the rare earths and he experienced great difficulties in positioning these elements. Question marks and wrong atomic weights reigned in the last rows of Mendeleev’s system. -/- This problematic accommodation quickly grew into one of the most serious threats for the periodic law. For over fifty years, chemists continually struggled with the placement of these maddeningly similar elements. As a consequence, a lot of chemists started to question the validity of the periodic law, but others took it as a sign that the concept of a chemical element had to be reconsidered. As a result, this work intends to retrace the mutual influence of the philosophical ideas about the nature of chemical elements and the development of the periodic table from its inception in 1869 to the discovery of Moseley’s law in 1913 and Bohr’s publication of his landmark paper On the Constitution of Atoms and Molecules. -/- The aim of this thesis is to show how, on the one hand, the periodic table (as a research instrument) helped in reformulating the contemporary ideas about chemical elements, and how it aided in developing a new research program in order to resolve the rare earth crisis. On the other hand, the question will be taken up to what extent Crookes’ evolutionary ideas about meta elements helped in saving the periodic table from a severe downfall by solving the gnawing problem of the rare-earth elements. In particular, this work will also focus on the investigations of the Czech chemist, Bohuslav Brauner. It will be shown how Brauner, under the influence of Crookes’ ideas, was led to his formulation of the Asteroid Hypothesis, according to which all the rare-earth elements should be placed in a single case of the periodic table. (shrink)

The history of the classification of chemical elements is reviewed from the point of view of a bibliophile. The influence that relevant books had on the development of the periodic table and, conversely, how it was incorporated into textbooks, treatises and literary works, with an emphasis on the Spanish bibliography are analyzed in this paper. The reader will also find unexpected connections of the periodic table with the Bible or the architect Buckminster Fuller.

This paper suggests that the cases made for atoms and the aether in nineteenth-century physical science were analogous, with the implication that the case for the atom was less than compelling, since there is no aether. It is argued that atoms did not play a productive role in nineteenth-century chemistry any more than the aether did in physics. Atoms and molecules did eventually find an indispensable home in chemistry but by the time that they did so they were different kinds (...) of entities to those figuring in the speculations of those natural philosophers who were atomists. Advances in nineteenth-century chemistry were a precondition for rather than the result of the productive introduction of atoms into chemistry. (shrink)

In 1931 eminent chemist Fritz Paneth maintained that the modern notion of “element” is closely related to (and as “metaphysical” as) the concept of element used by the ancients (e.g., Aristotle). On that basis, the element chlorine (properly so-called) is not the elementary substance dichlorine, but rather chlorine as it is in carbon tetrachloride. The fact that pure chemicals are called “substances” in English (and closely related words are so used in other European languages) derives from philosophical compromises made by (...) grammarians in the late Roman Empire (particularly Priscian [fl. ~520 CE]). When the main features of the constitution of isotopes became clear in the first half of the twentieth century, the formal (IUPAC) definition of a “chemical element” was changed. The features that are “essential” to being an element had previously been “transcendental” (“beyond the sphere of consciousness”) but, by the mid-twentieth century the defining characteristics of elements, as such, had come to be understood in detail. This amounts to a shift in a “horizon of invisibility” brought about by progress in chemistry and related sciences. Similarly, chemical insight is relevant to currently-open philosophical problems, such as the status of “the bundle theory” of the coherence of properties in concrete individuals. (shrink)

Two inter-linked theses are defended in this paper. One is the Duhemian theme that a rigid distinction between physical and chemical properties cannot be upheld. Duhem maintained this view not because the latter are reducible to the former, but because if physics is to remain consistent with chemistry it must prove possible to expand it to accommodate new features, and a rigid distinction would be a barrier to this process. The second theme is that naturally occurring isotopic variants of water (...) are in fact distinct substances, and naturally occurring samples of water are mixtures of these substances. For most practical purposes it is convenient to treat protium oxide, deuterium oxide, and so on, as the same chemical substance, but to insist on this as a matter of principle would stand in conflict with the first thesis. (shrink)

Over the last two hundred years, there have been many occasions where the name of a newly-discovered element has provoked controversy and dissent but in modern times, the naming of elements after scientists has proved to be particularly contentious. Here we recount the threads of this story, predominantly through discourses in the popular scientific journals, the first major discussion on naming an element after a scientist ; the first definitive naming after a scientist ; and the first naming after a (...) living scientist. (shrink)