Rationality and irrationality in the history of continental drift: Was the hypothesis of continental drift worthy of pursuit?

The revolution in geology, initiated with Alfred Wegener’s theory of continental drift, has been the subject of many philosophical discussions aiming at resolving the problem of rationality underlying this historical episode. Even though the debate included analyses in terms of scientific methodology, applications of concrete accounts of epistemic justification to this case study have been rare. In particular, the question as to whether Wegener’s theory was epistemically worthy of pursuit in the first half of the twentieth century, that is, in its early development, remained open or inadequately addressed. The aim of this paper is to offer an answer to this question. The evaluation of Drift will be done by means of an account of theory evaluation suitable for the context of pursuit, developed in ?e?elja and Straßer (accepted for publication). We will argue that pursuing the theory of continental drift was rational, i.e., that it was irrational to reject its pursuit as unworthy.     

Plotinus’s conception of unity and multiplicity as the root to the medieval distinction between lux and lumen

Plotinus resolved the paradox of the immanent transcendence, characterizing the relation between the One and the universe, through his theory of the two energeiai. According to this doctrine, all existents have an internal activity and an external activity: the internal activity comprises the true essence and substance of each being; the external activity is emitted outwards as its image. The source of the emission is thus present in the lower layer of being by virtue of its manifold images. The prominence given to light in elucidating this solution led to a distinction between two types of lights: an original light, corresponding to the internal energeia of every existent, and a secondary light, which is the outflow and image of the first light, existing outside of the luminous body.This paper demonstrates the striking similarity between these two Plotinian lights and the concepts of lux and lumen developed by two thirteenth-century philosophers: Robert Grosseteste and Albertus Magnus. Moreover, the paper contends that the purpose of these two medieval concepts of light was identical to what Plotinus had in mind when he first made the distinction: to account for the relation between the one and the many.     

3-OH-Kynurenine content and ommochrome formation in the developing compound eye ofEphestia kühniella

Summary The eye color ofEphestia kühniella is primarily determined by the ommochromes xanthommatin and ommin. The pigmentation, an important part of eye differentiation, occurs mainly during the pupal stage. Comparative studies on eye colour mutants indicate that a first step in ommochrome synthesis is the binding of the precursor 3-OH-kynurenine to developing pigment granules. Both xanthommatin and ommin are present from the early beginning of eye differentiation, and exhibit different developmental profiles.     

Role of the Raphe Magnus nucleus in morphine analgesia : studies with intracerebral microinjections in the rat]

Microinjections of low concentration of morphine (5 micrograms) into the nucleus Raphé Magnus of the Rat produce a strong analgesia that can be reversed by systemic naloxone, an opiate antagonist. The administration of naloxone (5 micrograms) into the Raphé Magnus considerably reduces the effects of intravenous morphine. The effects of microinjections of morphine are strongly reduced by Cinanserin, suggesting a role for serotoninergic mechanisms in morphine analgesia.     

The isotope effect: Prediction,discussion, and discovery

The precise position of a spectral line emitted by an atomic system depends on the mass of the atomic nucleus and is therefore different for isotopes belonging to the same element. The possible presence of an isotope effect followed from Bohr's atomic theory of 1913, but it took several years before it was confirmed experimentally. Its early history involves the childhood not only of the quantum atom, but also of the concept of isotopy. Bohr's prediction of the isotope effect was apparently at odds with early attempts to distinguish between isotopes by means of their optical spectra. However, in 1920 the effect was discovered in HCl molecules, which gave rise to a fruitful development in molecular spectroscopy. The first detection of an atomic isotope effect was no less important, as it was by this means that the heavy hydrogen isotope deuterium was discovered in 1932. The early development of isotope spectroscopy led to successes as well as problems. At the end of the paper I briefly comment on the relationship between theory, experiment and prediction in this area of spectral physics.     

Science,sensitivity and the sociozoological scale: Constituting and complicating the human-animal boundary at the 1875 Royal Commission on Vivisection and beyond

Arnold Arluke and Clinton Sanders (1996) have argued that human societies index both humans and animals as belonging to particular rungs of the social hierarchy. They term this multispecies ranking the “sociozoological scale”. This paper will investigate how claims at the 1875 Royal Commission on Vivisection about the sensitivity of particular species and breeds not only reflected assumptions about human social hierarchy but also blurred the boundaries between the human and the animal in the process. It will further be shown how these claims were informed by 18th and 19th century humanitarianism, classism, scientific racism and evolutionary theory, and how these influences combined in claims-making about the relative capacity of particular animals to sense pain and ethical duties towards them that followed from this sensitivity. Particular attention will be given to the opposing efforts of commissioners Thomas Henry Huxley and Richard Holt Hutton to demarcate human and animal sensitivity and exempt companion animals from vivisection respectively. The paper concludes by considering the sociozoological orders constituted by the 1876 Cruelty to Animals Act, particularly through its focus on calculating pain, and the legacy and limitations of this constitution.     

A Companion to the History of Science

Snell's law of refraction did not affect the study of optics until twenty‐five years after its publication in 1637 and by then its universality threatened to break down already. Two optical phenomena—colour dispersion and strange refraction—were discovered that did not conform to the sine law. In the early 1670s, Isaac Newton and Christiaan Huygens respectively investigated these phenomena. They tried to describe the irregular behaviour of light rays mathematically and to reconcile it with ordinary refraction. This paper discusses their investigations and aims at throwing new light on the history of seventeenth‐century optics. Both initially approached the problem in a mathematical way in which they built on Descartes' analysis of refraction. This is surprising because it contradicts their earlier dismissal of Descartes' account and it does not fit our picture of them as mathematical physicists. By looking more closely at their early investigations it becomes clear that Newton and Huygens first had to develop the approach to optics of their later writings. After Descartes placed the issue of the physical nature of light rays on the scientific agenda in 1637, they recognized its purport in their struggles with colour dispersion and strange refraction. It was at this point that their physical optics evolved from the traditional geometrical optics with which they had started.     

The effect of hexamethonium on the secretion induced by sodium deoxycholate in the rat jejunum

Summary The i.v. administration of hexamethonium reduces or abolishes net water secretion induced by sodium deoxycholate in the denervated rat jejunum. The findings suggest that a local nervous reflex may be involved in bile salt-induced intestinal secretion.This research was sponsored by grants from the Swedish Medical Research Council (14X-2855), from the Swedish Society for Medical Sciences, from Magnus Bergvalls Stiftelse and from the Medical Faculty, University of Göteborg.     

Maxwell's role in turning the concept of model into the methodology of modeling

This is a contribution towards a history and philosophy of modeling in its early stages in electromagnetism. In 1873, James Clerk Maxwell (1831–1879) hinted at the methodology of modeling at the end of his Treatise on Electricity and Magnetism. We focus on Maxwell's impact on physicists who immediately followed him, specifically Oliver Lodge (1851–1940) and George Francis FitzGerald (1851–1901). We begin with the role that the scientific concept of model played in the late nineteenth century, as assessed by Ludwig Boltzmann (1844–1906). We then discuss the role of hypothesis as a methodology, the appeal to (dynamical) illustration, and the way Maxwell applied model and working model in his studies of electromagnetism. We show that for Maxwell these key terms were kept distinct, but Lodge did not maintain these distinctions and, in this regard, FitzGerald followed Lodge. Notwithstanding Lodge's influence, Fitzgerald modified Maxwell's theory based on the mechanical model he designed, thereby implicitly taking the first step towards modeling. This methodology consists in drawing consequences from the (mechanical) model to the (electrodynamic) theory and modifying the latter in light of the functioning of the former. At the core of our argument is the thesis that it was a methodological novelty to move from the concept of model to the methodology of modeling. The introduction of modeling as a new methodology into physics in the late nineteenth century was a major event which deserves proper recognition.     

Integral equations between theory and practice: the cases of Italy and France to 1920

In 1899, Ivar Fredholm discovered how to treat an integral equation using conceptual methods from linear algebra and use these ideas to solve certain classes of boundary value problems. He formulated a theory allowing him both to unify large classes of problems and to attack several problems fruitfully. The historical literature on the theory of integral equations has concentrated largely on the unification that was afforded by Hilbert and his school, but has not throughly investigated the roots of the subject in the older theory of partial differential equations, as developed for instance by Fredholm himself but also by Volterra and Levi-Civita. By concentrating on work issuing from this older tradition, in particular on French and Italian work, the paper shows how the new theory of integral equations was enthusiastically received, especially for its fruitful applications to areas of mathematical physics such as hydrodynamics, elasticity, and heat theory.     

The effect of lidocaine on the secretion induced by cholera toxin in the cat small intestine

Summary The intraluminal administration of lidocaine, a local anaesthetic agent, inhibits the net loss of fluid into the intestinal lumen produced by cholera toxin in the cat. It is suggested that the activation of a nervous reflex is involved in the pathogenesis of cholera.This research was sponsored by grants from the Swedish Medical Research Council (14X-2855), from the Swedish Society for Medical Sciences, from Magnus Bergvalls Stiftelse and from the Medical Faculty, University of Göteborg.     

Pathways for excitatory and inhibitory innervation to the guinea-pig tracheal smooth muscle

Summary The trachea receives excitatory cholinergic innervation from the vagus nerve and the stellate ganglion. Inhibitory adrenergic fibres have the same sources. Those in the vagus nerve probably derive from high vagosympathetic anastomoses. Nonadrenergic inhibitory fibres have a preganglionic vagal supply.This study has been supported by grants from Magnus Bergvall Memorial Found and Harald and Greta Jeansson Foundation.     

The effect of Apamin® on nonadrenergic,noncholinergic nervous vasodilatations in the cat small intestine

Summary The intestinal vasodilation evoked by mechanical mucosal stimulation or by transmural electrical field stimulation was abolished by close i.a. injection of Apamin, a polypeptide originally isolated from bee venom. Apamin also blocked the vasodilatation induced by close i.a. infusion of vasoactive intestinal polypeptide (VIP). It is suggested that Apamin is a VIP receptor antagonist.This research was sponsored by grants from the Swedish Medical Research Council (14X-2855), from the Swedish Society for Medical Sciences, from Magnus Bergvalls Stiftelse and from the Medical Faculty, University of Göteborg.     

Number crunching vs. number theory: computers and FLT,from Kummer to SWAC (1850–1960), and beyond

The present article discusses the computational tools (both conceptual and material) used in various attempts to deal with individual cases of FLT, as well as the changing historical contexts in which these tools were developed and used, and affected research. It also explores the changing conceptions about the role of computations within the overall disciplinary picture of number theory, how they influenced research on the theorem, and the kinds of general insights thus achieved. After an overview of Kummer’s contributions and its immediate influence, I present work that favored intensive computations of particular cases of FLT as a legitimate, fruitful, and worth-pursuing number-theoretical endeavor, and that were part of a coherent and active, but essentially low-profile tradition within nineteenth century number theory. This work was related to table making activity that was encouraged by institutions and individuals whose motivations came mainly from applied mathematics, astronomy, and engineering, and seldom from number theory proper. A main section of the article is devoted to the fruitful collaboration between Harry S. Vandiver and Emma and Dick Lehmer. I show how their early work led to the hesitant introduction of electronic computers for research related with FLT. Their joint work became a milestone for computer-assisted activity in number theory at large.     

Facing glycosphingolipid–Shiga toxin interaction: dire straits for endothelial cells of the human vasculature

The two major Shiga toxin (Stx) types, Stx1 and Stx2, produced by enterohemorrhagic Escherichia coli (EHEC) in particular injure renal and cerebral microvascular endothelial cells after transfer from the human intestine into the circulation. Stxs are AB₅ toxins composed of an enzymatically active A subunit and the pentameric B subunit, which preferentially binds to the glycosphingolipid globotriaosylceramide (Gb3Cer/CD77). This review summarizes the current knowledge on Stx-caused cellular injury and the structural diversity of Stx receptors as well as the initial molecular interaction of Stxs with the human endothelium of different vascular beds. The varying lipoforms of Stx receptors and their spatial organization in lipid rafts suggest a central role in different modes of receptor-mediated endocytosis and intracellular destiny of the toxins. The design and development of tailored Stx neutralizers targeting the oligosaccharide–toxin recognition event has become a very real prospect to ameliorate or prevent life-threatening renal and neurological complications.     

Effect of chronic hypogastric denervation on the noradrenaline content of the vas deferens and the accessory male reproductive glands of the rat

Zusammenfassung Die vorliegenden Ergebnisse zeigen, dass auch langdauernde Dezentralisierung und dadurch bedingte Inaktivierung der kurzen adrenergischen Neurone, welche das Vas deferens und die akzessorischen männlichen Geschlechtsorgane der Ratte innervieren, keine Verminderung des Noradrenalingehaltes dieser Organe verursachen.

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This work has been supported by a grant from Stiftelsen Magnus Bergvalls Minne.     

The Early Development of the Algebraic Theory of Semigroups

In the history of mathematics, the algebraic theory of semigroups is a relative new-comer, with the theory proper developing only in the second half of the twentieth century. Before this, however, much groundwork was laid by researchers arriving at the study of semigroups from the directions of both group and ring theory. In this paper, we will trace some major strands in the early development of the algebraic theory of semigroups. We will begin with the aspects of the theory which were directly inspired by, and were analogous to, existing results for both groups and rings, before moving on to consider the first independent theorems on semigroups: theorems with no group or ring analogues. Dedicated to the memory of Professor W. Douglas Munn. This article was begun when the author was an EPSRC-funded research student at the University of York, UK, and completed at CAUL under FCT post-doctoral research grant SFRH/BPD/34698/2007.     

Peripherally located adrenergic neurons innervating the vas deferens and the seminal vesicle of the guinea-pig

Zusammenfassung Samenleiter und Samenblase vom Meerschweinchen besitzen eine besonders kräftige adrenergische Innervierung, die von Nervenzellen, die in unmittelbarer Nähe der Organe liegen, ausgeht.

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This work has been supported by grants from the United States Public Health Service (NB 02854-04) and from Stiftelsen Magnus Bergvalls Minne.     

Heuristics versus norms: On the relativistic responses to the Kaufmann experiments

The aim of this article is to provide a historical response to Michel Janssen’s (2009) claim that the special theory of relativity establishes that relativistic phenomena are purely kinematical in nature, and that the relativistic study of such phenomena is completely independent of dynamical considerations regarding the systems displaying such behavior. This response will be formulated through a historical discussion of one of Janssen's cases, the experiments carried out by Walter Kaufmann on the velocity-dependence of the electron's mass. Through a discussion of the different responses formulated by early adherents of the principle of relativity (Albert Einstein, Max Planck, Hermann Minkowski and Max von Laue) to these experiments, it will be argued that the historical development of the special theory of relativity argues against Janssen's historical presentation of the case, and that this raises questions about his general philosophical claim. It will be shown, more specifically, that Planck and Einstein developed a relativistic response to the Kaufmann experiments on the basis of their study of the dynamics of radiation phenomena, and that this response differed significantly from the response formulated by Minkowski and Laue. In this way, it will be argued that there were, at the time, two different approaches to the theory of relativity, which differed with respect to its relation to theory, experiment, and history: Einstein's and Planck's heuristic approach, and Minkowski's and Laue's normative approach. This indicates that it is difficult to say, historically speaking, that the special theory of relativity establishes the kinematical nature of particular phenomena. Instead, it will be argued that the theory of relativity should not be seen as a theory but rather as outlining an approach, and that the nature of particular scientific phenomena is something that is open to scientific debate and dispute.