The notion of nature in chemistry

If nature is by definition the object of the natural sciences, then the dichotomy ‘natural’ versus ‘chemical’, held by both chemists and nonchemists, suggests an idiosyncrasy of chemistry. The first part of the paper presents a selective historical analysis of the main notions of nature in chemistry, as developed in early Christian views of chemical crafts, alchemy, iatrochemistry, mechanical philosophy, organic chemistry, and contemporary drug research. I argue that the dichotomy as well as quasi-moral judgments of chemistry have been based on static and teleological notions of nature throughout history and that chemists, unlike physicists, have neglected the dynamic notion of nature. The second part provides a philosophical criticism of the former notions and argues for the latter as well as for an explicit discourse about values in chemistry.     

The dynamic nature of the bacterial cytoskeleton

Three of the four well-established bacterial cytoskeletal systems—the MreB, MinCDE, and FtsZ systems—undergo a variety of short-range and long-range dynamic behaviors. These include the cellular reorganization of the cytoskeletal elements, in which the proteins redistribute from a predominantly helical pole-to-pole pattern into annular structures near midcell. Despite their apparent similarity, these dramatic redistributional events in the three systems are in large part independent of each other. In addition, some of the cytoskeletal structures undergo oscillatory behavior in which the helical elements move repetitively back-and-forth between the two ends of the cell. The details and mechanisms underlying these dynamic cellular events are just now being revealed by fluorescence microscopy of intact cells, fluorescence photobleaching recovery studies, single molecule tracking techniques, and in vitro studies of the purified proteins.     

The history of science as the progress of the human spirit: The historiography of astronomy in the eighteenth century

In the eighteenth century, the historiography of astronomy was part of a wider discussion concerning the history of the human spirit. The concept of the human spirit was very popular among Enlightenment authors because it gave the history of human knowledge continuity, unity and meaning. Using this concept, scientists and historians of science such as Montucla, Lalande, Bailly and Laplace could present the history of astronomy in terms of a progress towards contemporary science that was slow and could be interrupted at times, but was still constant, regular, and necessary. In my paper I intend to explain how the originally philosophical concept of the human spirit was transferred to the history of astronomy. I also introduce the basic principles to which the development of the spirit is subject in astronomy, according to historians of astronomy. The third part of the paper describes how historians of astronomy took into account the effect of social and natural factors on the history of astronomy.     

The endocrine nature of the paranganglia of man

Brightly fluorescent paraganglia were found in the retroperitoneal tissue of adult man. The histofluorescence properties of the paraganglia indicate the presence of tryptophyl peptides, which might be of endocrine importance.     

The endocrine nature of the paraganglia of man

Summary Brightly fluorescent paraganglia were found in the retroperitoneal tissue of adult man. The histofluorescence properties of the paraganglia indicate the presence of tryptophyl peptides, which might be of endocrine importance.     

The rise of alternative bread leavening technologies in the nineteenth century

This article reveals how nineteenth-century chemists and health reformers tried to eradicate the use of yeast in bread, claiming they had devised healthier and more sanitary ways to raise bread. It describes the alternative technological solutions to baking bread, investigating factors that influenced their development and adaptation in the marketplace. A lack of scientific and cultural consensus surrounding yeast, what it was and what it did, fermented during this period. The conflict over yeast helped create a heterogeneous industrialization of the baking industry, changing processes and ingredients and creating new forms of bakery products. By examining the claims of promoters of rival scientific beliefs and technologies, as well as those of users and social commentators, we can see that technology’s eventual adaptation and impact on society is not predictable at its outset. Exploring the relationship between differing scientific beliefs, cultural understandings and alternative technologies also shows how science and industry cannot be isolated from their social and cultural context. The examination of the nineteenth-century technological development of commonplace commodities such as bread, baking powder and yeast, also reveals and explores a story that has not been told before in the history of science and technology. Why it has not been told is as enlightening as the story itself, revealing as it does our own privileging of what is important in science and history.     

The x-phi(les): unusual insights into the nature of inquiry

Experimental philosophy is often regarded as a category mistake. Even those who reject that view typically see it as irrelevant to standard philosophical projects. We argue that neither of these claims can be sustained and illustrate our view with a sketch of the rich interconnections with philosophy of science.     

The chemical nature of the pig blood-group substances dissolved in the serum

Zusammenfassung In Schweineseren finden sich die Blutgruppenantigene A, Na and Nb in gelöster Form. Aus den entsprechenden Schweineseren wurden einerseits die Totallipide, andererseits die Mucoproteide extrahiert und in immunologischen Hemmungstests auf ihre Aktivität im A- und N-System untersucht. Es ergab sich, dass die determinanten Gruppen der Na- und Nb-Antigene an Mucoproteide gebunden sind, während die determinante Gruppe des A-Antigens sowohl an ein Mucoproteid als auch an ein Lipid gebunden ist.