[Innovations from the Baltic Sea region: Nils Alwall, Lembit Norviit, Adolfs Martins Steins and the artificial kidney]. / Innovationen im Ostseeraum: Nils Alwall, Lembit Norviit, Adolfs Martins Steins und die künstliche Niere.

In connection with the construction of one of the first practical dialysis machines, medical historians emphasize the work of the Swedish physician Nils Alwall. Together with his colleagues, he developed a device in the 1940s that could implement the combination of dialysis and ultrafiltration with membranes (cellophane tubes). Little known is the involvement of the physicians Lembit Norviit from Estonia and Adolfs Martins Steins from Latvia, both coauthors of the influential research article Clinical extracorporeal dialysis of blood with artificial kidney that was published in The Lancet in 1948 and the transfer of knowledge between Estonian, Latvian and Swedish researchers.

Scientific traditions in conflict: the Rusconi-von Baer controversy on the embryology of frogs and the development of the cell theory.

In 1835, the meaning of the cleavage furrows in the division of frog eggs was the cause of a heated argument between the Italian naturalist Mauro Rusconi and Karl Ernst von Baer. These furrows were first described by Prévost and Dumas (Ann Sci Nat 2:100-121, 129-149, 1824b) who did not realize they cut the egg into separate masses. Rusconi (Développement de la grenouille comune depuis le moment de sa naissance jusque a son état parfait, Giusti, Milano, 1826) hypothesized a connection between the furrows and a peculiar crystallization of the content of the egg which eventually produced elementary molecules as the building blocks of the embryo. von Baer (Arch Anat Phys Wiss Med 6:481-509, 1834) was the first to establish a link between the furrows and an active process of dichotomous division he considered to be the basis for all further development and differentiation. The present paper analyses the theoretical reasons behind these divergent interpretations and focuses attention on their implications for the development of the cell theory and the conceptions of life. Prévost, Dumas and Rusconi interpreted cleavage and the whole embryonic development in the light of eighteenth-century scientific theories and the French materialism of the early nineteenth century, which explained life in terms of ordered molecular movement. Starting from other premises partly rooted in German philosophy von Baer (1834) gave a totally different picture which anticipated the cell theory and modern embryology.

Quantification of the early small-scale fishery in the north-eastern Baltic Sea in the late 17th century.

Historical perspectives on fisheries and related human behaviour provide valuable information on fishery resources and their exploitation, helping to more appropriately set management targets and determine relevant reference levels. In this study we analyse historical fisheries and fish trade at the north-eastern Baltic Sea coast in the late 17th century. Local consumption and export together amounted to the annual removal of about 200 tonnes of fish from the nearby sea and freshwater bodies. The fishery was very diverse and exploited altogether one cyclostome and 17 fish species with over 90% of the catch being consumed locally. The exported fish consisted almost entirely of high-valued species with Stockholm (Sweden) being the most important export destination. Due to rich political history and natural features of the region, we suggest that the documented evidence of this small-scale fishery should be considered as the first quantitative summary of exploitation of aquatic living resources in the region and can provide a background for future analyses.

[Sterilization surgeon and researcher: life and career of Benno Ottow (1884-1975)]. / Sterilisierungsoperateur und Forscher: Leben und Karriere Benno Ottows (1884-1975).

The activities of the gynaecologist and member of the Erbgesundheitsgericht Benno Ottow (1884-1975) in the "Third Reich" have been described in a couple of publications. During the Nazi dictatorship Ottow demonstrated great commitment to putting the ideological and legal demands into practice. Drawing on sources from private and state archives in Estonia, Germany and Sweden, this paper investigates the biography of Benno Ottow: from his time as a junior physician period in Estonia and Russia to his directorship of the Brandenburg gynaecological state hospital in Berlin-Neukölln and the postwar-years in Sweden.

Karl ernst von Baer's 'Uber Entwickelungsgeschichte der Thiere II' and its unpublished drawings.

In 1828 Karl Ernst von Baer (1792-1876) published his seminal Uber Entwickelungsgeschichte der Thiere. Beobachtung und Reflexion. In the preface he announced that a second volume with one copper plate would be finished 'in a few weeks'. However, it took nine years until the unfinished second volume was released, with four copperplates. In his 'Autobiography', von Baer did not clarify the reasons why he did not finish his research program of comparative embryology. The paper attempts to elucidate them, furnished by archival documents and von Baer's unpublished embryological drawings. Our sketch of a few figures will show that (1) von Baer searched for 'analogies' (homologies) as a unifying principle and (2) explained the mechanisms of embryogenesis by physiological reasoning (electromagnetism). The main objective is to show that technical problems in illustrating and conceptual difficulties impeded von Baer's ambitious research program.