During the 1840s and 1850s the British embryologist and histologist Martin Barry (1802-1855) propounded a bold and original thesis about the microscopic structure of animal and vegetable tissue. He maintained that minute double spirals were virtually ubiquitous in the makeup of a wide range of structures. This paper considers how a claim of this kind was consonant with a romantic image of scientific creativity with which Barry identified. It describes his partially successful strategies to convince contemporaries of the veracity of (...) his claims. Major figures in the field, such as Richard Owen and Jan Evangelista Purkyně, affirmed that Barry's spirals were real objects in nature. Others, notably William Sharpey, became convinced that the spirals were mere artefacts and that Barry was deeply flawed as a scientific investigator. The ultimate rejection of his hypothesis had much to do with the moral repugnance that Barry's attempts to gain credit for a major discovery evoked among influential medical scientists. This negative assessment of Barry as an investigator reveals the lineaments of an alternative ethic of scientific practice. (shrink)

What is the relation between things and theories, the material world and its scientific representations? This is a staple philosophical problem that rarely counts as historically legitimate or fruitful. In the following dialogue, the interlocutors do not argue for or against realism. Instead, they explore changing relations between theories and things, between contested objects of knowledge and less contested, more everyday things. Widely seen as the life sciences' first general theory, the cell theory underwent dramatic changes during the nineteenth century. (...) The dialogue establishes that each successive version of the cell theory was formulated -- each identity of the object cell was formed -- around a different material : cork, cartilage, eggs in cleavage, muscle. Such things thus serve as exemplary materials, in ways not described by standard concepts like induction, theory -testing, theory -laden observation, and construction. Still, how can theories and perspective possibly be honed on things if these are apprehended differently by different observers according to their interests, training, culture, or indeed theories? The second part of the dialogue addresses this problem, partly through the verbal and visual schemata that were used by nineteenth-century microscopists and that are comparable to schemata in the visual arts. The third part of the dialogue considers the exemplary materials as a historical sequence, itself needing explanation. Theoretical change devolved partly from wider histories and geographies of the prevalence, availability, or scientific and cultural status of materials such as plants, animals, and muscle. (shrink)

In the nineteenth century protozoology and early cell biology intersected through the nexus of Darwin's theory of evolution. As single-celled organisms, amoebae offered an attractive focus of study for researchers seeking evolutionary relationships between the cells of humans and other animals, and their primitive appearance made them a favourite model for the ancient ancestor of all living things. Their resemblance to human and other metazoan cells made them popular objects of study among morphologists, physiologists, and even those investigating animal behaviour. (...) The amoeba became the exemplar of the new protoplasmic cell concept of mid-century and because its apparent simplicity made it widely generalizable it became a popular subject in a breadth of experimental investigations and theoretical speculations. It was able to do this because "the amoeba" denotes not a particular organism, but a general type of behaviour common to the cells of a range of protozoa, simple plants and higher animals. Its status as an exemplary cell also rested upon auxiliary philosophical assumptions about what constitutes a primitive characteristic and the thesis that evolution is a progressive development of order from chaos. (shrink)

In a long-term transformation, that begins in Antiquity but takes a crucial turn in the Renaissance anatomies, the “fibre” becomes from around 1750 the operative building block and at the same time the first unifying principle of function-structure-complexes of organic bodies. It occupies the role that the cell takes up in the cell œconomies of the second third of the nineteenth century. In this paper, I will first discuss some key notions, technical analogies, and images that are related to “fibre”-concepts (...) from Andreas Vesalius to Albrecht von Haller and then focus on Charles Bonnet's and Denis Diderot's fibre œconomies. In Bonnet's and Diderot's fibre œconomies, the self-active, regulating properties of fibre-agents and their material structures, that reach from fibre bundles, tissues and membranes to apparati of organs, are united within the concrete whole of individual organized “systems” or “networks.”. (shrink)

These three books illustrate some key themes in the history of science and the history of microscopy. First is a new enthusiasm among some historians and philosophers of science to embrace the history of microscopy as an area worthy of study, a recognized area of investigation for the historian and philosopher of science. In so doing these historians have redefined the subject area from the more traditional and much researched history of microscopes, with its emphasis on the technical, to a (...) consideration of the community of practitioners of microscopy and the theoretical contexts in which they carried out their studies. They have attempted to view the practice of microscopy and its practitioners within a conceptual, philosophical, and social context. They have by no means excluded technical considerations, but have argued that those alone can explain neither the rise, flourishing, and apparent decline of microscopy in the seventeenth and eighteenth centuries, nor its resurgence in the nineteenth century. Rather, they have argued that an analysis of microscopy must include social and conceptual considerations in addition to the technical. With these three books we have moved at last from the history of microscopes to the history of microscopy, within the context of the history and philosophy of science. The history of microscopy can now take its place within the larger inter-disciplines of HPS and STS. (shrink)

A collection of essays investigating key historical and scientific questions relating to the concept of natural purpose in Kant's philosophy of biology.

The ArgumentMicroscopical consideration played a crucial role in German physiology in the period of, grosso modo, 1780–1830. Specifically, a conception of material change was established, according to which all life is grounded in the process of the generation of microscopical forms out of an amorphous, primitive generative substance. Embryological development, tissue growth, and the generation of microorganisms were all considered to be the manifestation of this fundamental developmental process. In contrast to the common historiography, I try to understand Theodor Schwann's (...) 1838 discovery of the cell theory in terms of the epistemological categories he applied to the prevailing conceptions of life and living matter. I argue that Schwann was able to discern cells not because of any superior microscopical methods, but rather as part of his wider investigative endeavor to explicate life processes according to specific causal agents. I argue that Schwann was able to demonstrate the existence of cells only when he considered animal tissues in terms of a causal relation between specific material agents and their effect, that is, the developmental history of tissue. (shrink)