Ein bisher unbekanntes Zeitzeugnis: Otto Warburgs Tagebuchnotizen von Februar-April 1945

Warburg's diary notes February-April 1945 Personal notes in the form of a diary, written by the German cell biologist Otto Warburg in the weeks before the collapse of Germany's Third Reich (Feb.-April 1945), were found at the end of one of his laboratory notebooks, which are preserved in the Archives of the Berlin-Brandenburg Academy of Sciences and Humanities. These notes are unique in form and content: there seem to be no other surviving diary notes of this type. Written from a very personal perspective, they provide a detailed account of how Warburg experienced local events in this decisive and turbulent period. Furthermore, they clearly demonstrate Warburg's embittered attitude towards some of his long-standing collaborators, whom he suspected of having denounced him to the Nazi authorities. In this paper, Warburg's notes are fully transcribed and integrated into the historical contex

Otto Warburg's first approach to photosynthesis

In the field of photosynthesis research, Otto Warburg (1883-1970) is predominantly known for the role he played in the controversy that began in the late 1930s regarding the maximum quantum yield of photosynthesis, even though by that time he had already been working on the topic for more than a decade. One of Warburg's first contributions on the subject, which dates from around 1920, is his proposal for a detailed model of photosynthesis, which he never completely abandoned, despite later overwhelming evidence in favor of alternatives. This paper presents a textual and graphical reconstruction of Warburg's model and of his argument for its validity. Neither has received much attention in the history of science, even though the model was certainly one of the most plausible explanations of the period and therefore could not be so easily discredite

The Gentleman and the Rogue: The Collaboration Between Charles Darwin and Carl Vogt

This paper investigates the relationship between the eminent 19th-century naturalists Charles Darwin and Carl Vogt. On two separate occasions, Vogt asked Darwin for permission to translate some of the latter's books into German, and in both cases Darwin refused. It has generally been assumed that Darwin turned down Vogt as a translator because of the latter's reputation as a radical libertine who was extremely outspoken in his defence of scientific materialism and atheism. However, this explanation does not fit the facts, since, on closer investigation, Darwin not only gave serious consideration to engaging Vogt as the German translator of two of his books, albeit ultimately rejecting him, but he also collaborated with Vogt on the French editions of his works. In this paper we argue that this was not because Darwin was unaware of Vogt's personality and blunt writing style; rather, Darwin seems to have decided that the benefits he would gain from their association would clearly outweigh the risk of offending some of his readers: in working with Vogt, who was not only a knowledgeable scientist but also an avowed adherent of Darwinism, Darwin could be assured of the scientific quality of the translation and of an edition that would not distort his central concepts - both of which were by no means matters of course in 19th-century translations of scientific work

Evolution of the Z-Scheme of Electron Transport in Oxygenic Photosynthesis

We start with the discussion of the photosynthetic unit, based on the experiments of Emerson and Arnold (1932a, 1932b), continue with the first two-quantum proposal by Rabinowitch (1945, 1956), Emerson's Red drop (1943) and Emerson Enhancement Effect (1957) and various action spectra made for understanding the roles of the photosynthetic pigments. The experimental work of Kok (1959) and the theoretical model by Hill and Bendall (1960) were followed soon thereafter by the seminal papers of Duysens et al. (1961) and Duysens and Amesz (1962), in which the two photosystems were shown to be connected, in series, by cytochrome, which can be photooxidized by photo system I and photoreduced by photosystem II. Further, Witt et al. (1961) and others, cited in this paper, made refinement of the Z-scheme

Why the dilemma of case studies misses the point: Towards an explicit methodology for integrated history and philosophy of science

We respond to two kinds of skepticism about integrated history and philosophy of science: foundational and methodological. Foundational skeptics doubt that the history and the philosophy of science have much to gain from each other in principle. We therefore discuss some of the unique rewards of work at the intersection of the two disciplines. By contrast, methodological skeptics already believe that the two disciplines should be related to each other, but they doubt that this can be done successfully. Their worries are captured by the so-called dilemma of case studies: On one horn of the dilemma, we begin our integrative enterprise with philosophy and proceed from there to history, in which case we may well be selecting our historical cases so as to fit our preconceived philosophical theses. On the other horn, we begin with history and proceed to philosophical reflection, in which case we are prone to unwarranted generalization from particulars. Against worries about selection bias, we argue that we routinely need to make explicit the criteria for choosing particular historical cases to investigate particular philosophical theses. It then becomes possible to ask whether or not the selection criteria were biased. Against worries about unwarranted generalization, we stress the iterative nature of the process by which historical data and philosophical concepts are brought into alignment. The skeptics’ doubts are fueled by an outdated model of outright confirmation vs. outright falsification of philosophical concepts. A more appropriate model is one of stepwise and piecemeal improvement

The Challenge of Colour

Colourful plant images are often taken as the icon of natural history illustration. However, so far little attention has been paid to the question how this beautiful colouring was achieved. At a case study of the eighteenth-century Nuremberg doctor and botanist Christoph Jacob Trew the process of how illustrations were hand-coloured, who were involved in this work and how the colouring was supervised and evaluated is reconstructed, mostly based on Trew’s correspondence with the engraver and publisher of his books, Johann Jacob Haid in Augsburg. Furthermore, the question of standardising colours, their uses and their recipes is discussed at two examples of the same time period: the colour charts of the Bauer brothers, arguably the most renowned botanical draughtsmen of the period, and the colour tables by the Regensburg naturalist Jacob Christian Schaeffer. Hand-colouring botanical illustrations, it is argued, was far from a straightforward task but confronted botanists and their employees with a plethora of practical and methodological problems, to which different solutions were developed in the course of time. Analysing these problems and solutions reveals some new and interesting aspects of the practices of eighteenth-century botany and of the production of scientific illustrations in general