Abstract Ole Worm, Professor of Medicine at Copenhagen University 1624–1654, collected natural objects and artefacts with a view to letting students learn through observation and the touch of real things. Among the objects were fossils. Through Worm’s correspondence from 1607 to 1654, his growing understanding of petrifaction and petrifactions (fossilization and fossils) and its circumstantial background in the Nordic Renaissance has been investigated. Worm studied medicine with anatomy, botany and (iatro)chemistry at European universities. He began as Professor Pædagogicus and practising physician in Copenhagen in 1613 and he pursued interests in botany and in Nordic philology supported by King Christian IV. Objects for demonstrative instruction were obtained through his correspondents and were arranged systematically in Worm’s museum. The first fossils were identified chemically as petrified mollusc shells and wood, but without attention to species and original environment. With limited zoological knowledge and little field experience, but well trained in anatomical observation and description, and well read, Worm developed his understanding of fossils. He compared sharks’ teeth and glossopetrae , adding evidence to former comparisons. Christian orthodoxy was a barrier to geological and evolutionary thinking. Worm rejected superstition and prepared the way for the scientific comprehension of fossils in the Nordic cultural sphere.

ABSTRACT During the first half of the seventeenth century, the Danish polyhistor, Ole Worm (1588–1654), established a collection in Copenhagen, the Museum Wormianum, consisting of minerals, plants, animals, and man-made objects. The collection attracted visitors and was renowned throughout Europe; however, Worm also used it as a site for teaching his university students. Even though Worm did not contribute significantly to the history of science with new discoveries, this article argues that he played a role in shaping an intellectual environment founded on international exchange in which discussions took place, methods were enhanced, and talents were supported. In this context, his museum had an important function as a site of attraction and exchange, anticipating social interaction and learning, even when Worm himself could not participate.

Abstract This paper concerns the Danish anatomist Nicolaus Steno’s years in the service of the Medici Court and argues that his studies of the Earth in Canis cacharia dissectum caput from 1667 and De Solido intra solidum contento dissertationis prodromus from 1669 must be interpreted within this context and in relation to the epistemological approach of the historia -genre present in many early modern medical textbooks. The use of historia enabled Steno to produce knowledge that was both useful as a Medicean instrument of power and allowed him to produce a truthful geological thesis without referral to Aristotelian causes. Traditionally, Steno’s geological work has been interpreted teleologically, as a break from contemporary natural philosophy and as an example of a foresight which would not be appreciated properly until several hundred years after his death. Challenging the untenable presentist interpretation, this paper argues that Steno’s work on the transformation of the Earth must be understood as inherently connected to the Medici court and their experimental academy – the Accademia del Cimento.