Niels Stensen Research Articles

The Volterra cliff in the mind of philosophers, savants and geologists (1282–1830)

Abstract The Pliocene fossiliferous succession of the Volterra hill, a prominent place in Tuscany, Italy and, since the Renaissance, the site of important archaeological finds of the ancient Etruscan civilization, has formed the object of enquiry over six centuries of research on the inner nature of the Earth system. The works of Restoro d'Arezzo, Leonardo da Vinci, Nicolaus Steno, Giovanni Targioni, Nicolas Desmarest, Giambattista Brocchi, Alexandre Brongniart and Charles Lyell testify to the early recognition through fieldwork that those strata with seashells had formed at the bottom of the sea. This interpretation served different approaches to knowledge. Restoro, Leonardo and Steno, spanning nearly four centuries in the history of science (1282–1669), including the ‘Copernican Revolution’ and the start of the Modern Age, relied also on textual sources and trusted a speculative model of the Earth's interior, so that at Volterra they focused on vertical movements of the earth–water system. The authors of the eighteenth and nineteenth centuries abandoned pre-built young-Earth models and emphasized the geography of ancient Tuscany. Brocchi, Brongniart and Lyell promoted the taxonomic use of seashells to correlate rocks across Europe. This place deserves higher standards of valorization to promote understanding of the history and sociology of ideas.

Drawing muscles with diagrams: how a novel dissection cut inspired Nicolaus Steno's mathematical myology (1667)

In 1667, twenty years before Isaac Newton published his mathematization of physics, and more than ten years before the publication of Giovanni Borelli's De motu animalium , the Danish anatomist Nicolaus Steno published an entirely new geometrical theory of muscle motion in the book Elementorum myologiæ specimen . Historians of science have studied this book in recent decades, but the recent rediscovery of a seventeenth-century muscle atlas at the Bibliothèque interuniversitaire de Santé in Paris sheds new light on the largely overlooked origin of Steno's mathematical theory of muscles. In this article, we show that Steno's muscle diagrams result from a tension that Steno faced when combining his interest in illustrations with presenting his mathematical insights about the inner structure of muscle fibres. Furthermore, we argue that Steno's diagrams are deeply connected to observations through a new method of dissecting the muscles. The observational origins of Steno's mathematical insight are further confirmed by the strong correlation between Steno's depictions of the structure and function of skeletal muscles and the results of current biomechanical investigations.

Physico-mathematics and the life sciences: experiencing the mechanism of venous return, 1650s–1680s

ABSTRACT This article deals with physico-mathematical approaches to anatomy in post-Harveyan physiology. But rather than looking at questions of iatromechanics and animal locomotion, which often attracted this approach, I look at the problem of how blood returned to the heart – a part of the circulation today known as venous return but poorly researched in the early modern period. I follow the venous return mechanisms proposed by lesser-known authors in the mechanization of anatomy, such as Jean Pecquet (1622–1674) and Nicolaus Steno (1638–1686), alongside the more famous Giovanni Alfonso Borelli (1608–1679). Their mechanisms differed only in small details. Yet, these minor differences highlight significant aspects of the mechanization of the life sciences in the seventeenth century. First, they relied more on observations than hitherto acknowledged, even if only indirectly. Second, their mechanisms drew more from the physico-mathematical disciplines than from the trending corpuscularian philosophies of their time. Finally, these mechanisms led to a more accurate understanding of the circulation that remains valid today, thus revealing their cognitive benefits. In short, through the single problem of how blood returned to the heart, this article portrays the increasing complexity of anatomy in the early modern period.

Health-care provision for displaced populations arriving from Ukraine

Health-care provision for displaced populations arriving from Ukraine

William Poole. The World Makers: Scientists of the Restoration and the Search for the Origins of the Earth.

William Poole. <i>The World Makers: Scientists of the Restoration and the Search for the Origins of the Earth.</i>

Archaeological Stratigraphy and the Bifurcation of Time: Solido intra solidum

The goal of this paper is to explore the ways solidity and fluidity have been articulated in relation to understandings of time and the archaeological record. It reflects on the paradox that led the 17th-century Danish scholar Nicholas Steno to write one of the first discourses on stratigraphy: how can solid objects (such as fossils) occur within other solid objects (rock)? His dissertation ( De solido intra solidum naturalitur contento, 1669) offered the simple solution: the containing solid was once a fluid. However, such a solution came at a cost which still haunts contemporary understanding of the archaeological record: a bifurcation of time into past and present expressed through the ideas of archaeological statics and dynamics. In addressing the way ‘solid fluids’ are entangled with time and archaeological stratigraphy, this paper attempts to draw novel perspectives on all three.

Nicolaus Steno on solutes and solvents in time-related structural changes of muscles, fossils, landscapes and crystals, his galilean heritage

In Part One of the Specimen of Elements of Myology, a book in three parts published in Florence 1667, Nicolaus Steno described the changes taking place between muscle relaxation and contraction in a two-stage geometrical model based on anatomical observations in man and animals. The ‘new myology’ was rejected by G.A. Borelli in 1680 and outright ridiculed by J. Bernoulli in 1694. The anatomical correctness and predictive value was rightfully acknowledged only towards the Millennium. In Part Two, the Canis …, Steno gave a detailed anatomical description of a giant shark’s head with focus on the likeness of its teeth and the so-called tongue stones, or “glossopetrae”, dug from the ground. Steno conjectured that remnants from sharks living in the past had become fossils due to chemical processes through interaction with the surrounding sediments at the bottom of the sea, presuming that the finding areas had been sea-covered. From studies in Part Three of reproductive organs in mammals, viviparous ray-fish and shark, he concluded that the so-called female testicles in women and mammals are analogous with ovaries of oviparous animals and should therefore be named accordingly. Two years later in the Prodromus De Solido intra Solidum, Steno described the transformation over time of sedimentary landscapes in Tuscany, and how crystals grow by accretion to the surface of entities derived from limpid sea-water or freshwater in caves. These are studies of time-related transformations of solids in organic and inorganic materials. However, such processes could not be documented by visual observation, since changes go too quickly in muscles, in the case of the landscapes because the transformations took place in the past. Thus, Steno and contemporaries put forward hypotheses on such hidden processes that were only gradually corroborated when fitting into a cluster of evidence. His considerations on crystal growth may have been triggered by an interest as a physician to know how saliva, gall and kidney stones are formed. Likewise, considerations on sharks’ replacement of their teeth could extend knowledge on dentition to bring a better cure for those who complain of being toothless. He emphasized the importance of mathematical methods to describe processes in the human body and cited from Galileo, Discourse on Bodies in Water (1612), in which physics outweighs Aristotelian rules to explain the interaction of solids and solvents. Likewise, Steno’s ‘New Myology’ was a showdown against an Aristotelean physical dogma from Physics VII: everything which moves is moved by another, which excluded fibre shortening in muscles and blinded researchers on muscle contraction for generations after Steno.

Steno and the rock cycle

Geologists categorize the basic types of rock according to their origin – igneous, sedimentary, or metamorphic -- rather than by their physical properties. This is expressed dynamically by the fundamental concept of the rock cycle, which describes how the basic rock types are derived from one another within the Earth system as a result of ongoing cyclic geologic processes. In Nicolaus Steno’s published geological work, particularly De Solido, he takes a similar approach, outlining how a substance can be examined “to disclose the place and manner of its production”. Steno also recognizes the roles of erosion, transport, and deposition in the production of sedimentary strata from pre-existing earth materials. His description and diagrams of the geological evolution of Tuscany also show a clear cyclicity of process. While the modern concept of the rock cycle did not emerge until the 19th century, Steno’s work contains key elements of this important concept.

Dissecting with numbers: mathematics in Nicolaus Steno’s early anatomical writings, 1661-64

At the height of his scientific career, the anatomist Nicolaus Steno published the Elementorum myologiæ specimen (Florence, 1667), a book unlike any other anatomy book until then. Rather than an anatomy book, it seemed more like a book of mathematics, with propositions, lemmas and corollaries. Steno is thought to have developed his mathematical interests in Florence with the school of Galileo. However, this article challenges this interpretation and argues that Steno’s turn towards mathematics was a gradual process that began earlier in Copenhagen and Leiden. By surveying Steno’s early anatomical writings, mathematical methods such as quantification measurements, mechanical analogies, and geometrical models come to light. More importantly, these methods are read in their own context, by considering what mathematics really meant in the early modern period and how anatomists have used it in history. As such, this article provides a more complete picture of Steno’s interest in mathematics and it sheds new light on the rise of mathematics in the early modern life sciences.

Introduction: Nicolaus Steno and earth science in early modern Italy

A group of scientists interested in history of science and fascinated by the figure of Nicolaus Steno (1638-1686) gathered in Florence for the 350th anniversary of the publication of his De solido intra solidum naturaliter contento prodromus dissertationis. A public conference held at Palazzo Fenzi on 16 October 2019 and a geological fieldtrip on the following day were occasions to discuss different points of view on the last published work of the Danish natural philosopher, dedicated to "solids naturally enclosed in other solids" (De solido intra solidum naturaliter contento, or De solido in short). The title of the gathering, "Galilean foundation for a solid earth", emphasized the philosophical context that Steno found in Florence, where in 1666-1668 he established tight human and philosophical bonds with renowned Italian disciples of Galileo Galilei and members of the Accademia del Cimento. For participants to the 2019 gathering, the Museum of Natural History of the University of Florence, hosting some of Steno's geological specimens, and the region of Tuscany itself, formed the perfect location to discuss the phenomena that Steno had observed from 1666-1668, the motivations for his research, the methodology of his discovery and, generally stated, the European scientific context which informed his inquiry. Some of the talks given in that meeting are included within this volume, kindly hosted by Substantia, International Journal of the History of Chemistry published by the Florence University Press. In addition some of the invited speakers who were unable to attend, also contributed a paper to this publication. The collection is about earth science in the early modern period, when the study of minerals, rocks, and the fossilized remains of living things did not yet form a distinct path to knowledge about earth history, but was an integral part of the wider "philosophy of nature".

Crystalline stenonian time features from earth and beyond

The writings of Niels Stensen (Steno) on mineral growth and modification in his Prodromus, together with his work on time and process in other solids, are here synthesized as five classes of time features defined by changes in the visible continuity of either or both chemistry and orientation. This organization highlights Steno’s implicit recognition of the fractal, scale-invariant nature of natural time features with regard to space, time, and material. The effectiveness and validity of this Stenonian geochronology framework is demonstrated down to atom scale with modern case studies of the U-Pb geochronology mineral zircon from samples originating from the Earth, Moon, and Mars and spanning most of solar system history. Recently discovered nano-scale features, here termed chronostructures, were intimated by Steno in his corpuscular view of mineral behaviour. The remarkable advances in the Prodromus are seen here as a resulting from the intersection of Steno’s highly attuned approach to visual perception, his adoption of Stoic (Senecan) ethics early in his career to guide his natural philosophy, and the influence of the Galilean scientific environment of Florence. It is shown that, by virtue of its scale-invariant and intensive properties, Stenonian geochronology continues to serve as an independent and critical check on the accuracy of absolute geochronology measurements of geologic time given the latter’s inherent dependence on sample volume and the assumption of the chemically closed system. In this way Steno’s scientific legacy continues to help propel human understanding of how we see our place in time.

A man with a master plan: Steno’s observations on earth’s history

We present specific sources, including specimens of the Medicean cabinet and geological outcrops in Tuscany, probably used by Nicolaus Steno to build a theory on the origin of organic fossils, crystals and sedimentary strata, in order to construct the history of the Earth based on universal geometric principles. Phenomena he observed in Tuscany and in precedeing travels were revealing a sequence of events consistent with the biblical account. We propose that he devised his method to reconstruct a chronology of primordial events to demonstrate the historicity of the biblical creation in contrast to unorthodox thinking. This had been spreading in philosophical circles of northern Europe since the 1650s, circles frequented by Steno before his arrival in Tuscany in 1666. Steno knew in advance what places to visit to find fossils from literature such as Michele Mercati’s Metallotheca. This was a manuscript owned by the Florentine Carlo Dati, whom Steno probably heard about while in Paris in 1664-1665. In Tuscany he soon formed a tight interaction on matters regarding the interpretation of fossils with the local community of learned men. These included Giovanni Alfonso Borelli who was asked by Prince Leopoldo de’ Medici to provide Steno with fossils from Sicily and Malta. Steno’s theory and scale-independent, geometrical method of inquiry of geological objects found in Tuscany is hinted at in his Canis Carchariae Dissectum Caput, a geological essay completed in a few months in 1666. The theory was published in its most complete form in the so-called Prodromus of 1669. In both works he demonstrated that fossils in younger strata in the Tuscan hills, such as shark teeth and molluscan shells, have an origin analogous to solids which living animals form. In both essays he explicitly related the deposition of strata with marine fossils to the biblical flood, an idea foreshadowed in his oldest known manuscript of 1659, when he was a student in Copenhagen. He found no fossils in older sandstones of the Apennines and understood those strata to have formed before the creation of life. These discoveries and other observations he made in Tuscany were, for Steno, the final proof that natural philosophy and biblical revelation disclose in synergy the mysteries of God’s creation.

The earliest-published recognition of a trace fossil and its producer

The recognition of fossil material as organic represented a sea change in European understanding of geology. Throughout the Renaissance and Early Modern periods, several thinkers approached the same line of reasoning, from Leonardo da Vinci to Nicolas Steno. Among fossil material, trace fossils are furthest removed from the living organism, and the identification of trace fossils as such is extremely rare in the period, even when body fossils were increasingly being seen as organic. Alongside Leonardo da Vinci, whose personal observations in the early 16th century remained unpublished for centuries, and Ulisse Aldrovandi, whose account of trace fossils was published posthumously in 1648, I here show that Bernard Palissy also recognised the biological origins of at least one form of trace fossil. The publication of Palissy’s identification occurred in 1580, 68 years before Aldrovandi’s was published, and 23 years before the manuscript on which that publication was based. Moreover, like Aldrovandi, Palissy’s recognition includes specific identification of the trace as being produced by pholad molluscs. Palissy’s is therefore the oldest example of an ichnological identification to be found in the published literature.

On the history of discovery of ductus parotideus

An article provides author’s translation from Latin of Niels Stensen’s letter to his teacher Thomas Bartholin, describing circumstances of Stensen’s discovery of parotid duct as well as vicissitudes of recognition of his priority but not Gerard Blaes’ one, who credited himself discovery of ductus parotideus. Brief data on Niels Stensen’s life is given, his contribution to medicine and geology is described.

Life of Niels Stensen (1638-1686), who was the Pioneer Scientist and Great Neuroanatomist

Danish scientist, Niels Stensen was a prosperous anatomist and in addition to that a pioneer in the areas of paleontology, geology, mineralogy and bishop. With his studies on subjects of anatomy, neuroscience, paleontology, mineralogy and geology Niels Stensen has major scientific contributions despite the difficult circumstances until his death at very young age.

Lectures de Descartes ed. by Frédéric de Buzon, Élodie Cassan, and Denis Kambouchner (review)

Reviewed by: Lectures de Descartes ed. by Frédéric de Buzon, Élodie Cassan, and Denis Kambouchner Steven Nadler Frédéric de Buzon, Élodie Cassan, and Denis Kambouchner, editors. Lectures de Descartes. Paris: Éditions Ellipses, 2015. Pp. 515. Paper, €35.00. A fair number of recent monographs and essay collections on Descartes cover the same old ground, rehashing well-worn problems (and well-worn solutions) and taking us for another tour in Cartesian circles. Much to be preferred are those studies that go beyond the familiar and truly advance our understanding of Cartesian metaphysics, epistemology, science, ethics, and philosophical theology, especially with new insights into their complex relationships. The best anthologies will also contain original essays by both well-established scholars and new colleagues, thus providing a nice snapshot of the state of the art at the time of publication. There is much to be learned about the development of the field by comparing, for example, the Anglo-American essay collections on Descartes from the 1960s and 1970s—mostly analytic pieces focused mainly on the Meditations—with more recent volumes containing historically and textually sensitive essays by international casts that cover a wider range of Descartes’s writings and their philosophical, scientific, political, and religious contexts. Lectures de Descartes, a collection of essays by European scholars, is a superb case in point. It is part of a series titled “Lectures de. . .” that includes volumes on early modern, late modern, and recent thinkers and trends, including Hobbes, Spinoza, Kant, Bourdieu, Sartre, and analytic philosophy. The goal of the editors of this Descartes volume is to take us beyond a caricatured Descartes who has been reduced to certain overworked themes (hyperbolic doubt, the cogito, the provisional ethics, etc.) and give the reader a better picture of the rich variety of topics that Descartes addressed as well as a finer sense of “la densité et l’inventivité” of his philosophical views. The charge they set for the French, Italian, and Dutch contributors is to put to rest Descartes’s image as a thinker whose only legacy is a bundle of errors, and to dispel some of the prejudices that have tainted his reputation and the reading of his works. As the editors put it, they seek “à déplier des complexités le plus souvent ignorées, et d’abord à rendre à la pensée cartésienne les nuances qui en sont constitutives” (7). We are, they insist, far from being finished with trying to understand what Descartes really wanted to accomplish and precisely how he went about doing it, whether in general or on some specific topic or another. While I do not believe that the best recent scholarship on Descartes is guilty of the reduction, prejudice, and caricaturing that the editors cite, still, on this last point, they are absolutely right. And what the chapters of this book, taken together, are intended to provide is a holistic understanding of Descartes’s project by revealing the intimate relationships among its various parts—especially the connection between his metaphysics and his “science,” so often separated (the editors say) by those who think that the former alone is worth the trouble of examining and by those who believe that the latter can be detached from its metaphysical foundations. On these terms, the chapters succeed admirably. The pair of essays by Stefano Di Bella (“Le programme métaphysique de Descartes”) and Frédéric de Buzon (“Le concept de la physique”) does an especially good job of providing an integrated picture of these two parts [End Page 168] of Descartes’s scientific project. Denis Kambouchner’s chapter on Descartes and political theory (“L’horizon politique”), a rarely discussed topic, while conceding that in an important sense there really is no politique cartésienne, manages to draw some intriguing conclusions from a letter to Elizabeth and to consider its Machiavellian background. Delphine Antoine-Mahut’s chapter on Descartes’s mechanistic account of the human body (“La machine du corps”) draws on some of Descartes’s less studied writings as well as the anatomical works of Nicolas Steno and William Harvey. To be sure, some of the essays do cover familiar territory and stick fairly closely to the...

Nicolaus Steno: Biography and Original Papers of a 17th Century Scientist ed. by Troels Kardel, Paul Maquet (review)

Reviewed by: Nicolaus Steno: Biography and Original Papers of a 17th Century Scientist ed. by Troels Kardel, Paul Maquet Marco Bresadola Troels Kardel and Paul Maquet, eds. Nicolaus Steno: Biography and Original Papers of a 17th Century Scientist. Berlin: Springer-Verlag, 2013. xxxviii + 739 pp. Ill. $139.00 (978-3-642-25078-1). Niels Steensen (Nicolaus Steno) was a major seventeenth-century Danish man of science who deserves continual in-depth historical study. He was the author of fundamental works in anatomy and geology, such as Elementorum miologiae specimen and De solido intra solidum prodromus. He was connected with prominent European scholars such as Thomas Bartholin, and with important scientific academies, including the Tuscan Accademia del Cimento. Reflecting the religious tensions typical of the time, he was educated in a Lutheran family, converted to Catholicism when he established himself in Tuscany, and finished his life as a bishop in northern Germany. The volume edited by Kardel and Maquet is thus a welcome contribution to the knowledge of the life and work of this very interesting figure. The volume is divided into three parts. The first part is the English translation of a biography of Steno written in German by Gustav Scherz and originally published in 1987. The second part is the English translation of Steno’s scientific papers, based on the edition of Nicolai Stenonis opera philosophica made by Vilhelm Maar in 1910. The third part includes the transcription of Steno’s anatomical [End Page 342] works in their original languages together with Maar’s scholarly annotations to his edition of Steno’s opera. The last part, however, is not to be found in the volume, but can be downloaded from the publisher’s website (which was unfortunately under maintenance in August 2014, when this review was written). In fact, the volume is more complex than this brief description indicates, as the two editors have added their own notes to Scherz’s biography and Steno’s works, have included new material such as a short discussion of “Stensen’s myology after Scherz” by Kardel (pp. 171–72), and have made some personal choices. For instance, they have omitted those original texts that can be found otherwise in print or in the web. Although these choices are clearly stated in the preface to the volume, some of them are rather unconvincing, like the decision to leave out the translation of some pages of the Elementorum miologiae specimen because their content is “without basis in observations” (p. 550, note a). According to the volume’s editors, Scherz’s work is the most exhaustive biography on Steno. It is a detailed reconstruction of Steno’s family and education, the periods he spent in Holland and France in the early 1660s, and his ten-year stay in Tuscany, interrupted by a long journey in Europe and a brief stay in Denmark. In 1677 his life changed abruptly, when he was nominated a Catholic bishop and began his religious career, which led him to several places in Germany until his death, in November 1686. This last part of Steno’s life was treated by Scherz in a second volume of his biography, which is not however included in Kardel and Maquet’s edition. This is a pity, and one can agree with the editor’s call for a new edition of the second volume of Scherz’s biography and of Steno’s theological papers. Scherz’s knowledge of Steno’s life and work is extensive, based not only on the published works of the Danish scholar, but also on the latter’s manuscripts and correspondence, which he also partly edited. His main interest, however, is for Steno’s religious ideas and trajectory from Lutheranism to Catholicism, which he, who was a Catholic priest, considers full of significance and exemplar. Indeed, he has been one of the main promoters of Steno’s beatification, which eventually came in 1988. Other aspects of Steno’s science are less developed in Scherz’s biography, as for instance his research on glands, whose implications were much wider than a simple dispute about who first discovered the parotid duct, on which Scherz mainly focuses. As a whole, however, Scherz’s biography...

Steno-Fallots tetralogi og Bartholin-Pataus syndrom. En hjertemisdannelse og et misdannelsessyndrom første gang beskrevet af danske anatomer i 1600-tallet

Jesper Brandt Andersen &amp; Niels W. Bruun: Tetralogy of Steno-Fallot and Bartholin-Patau syndrome. A heart malformation and a malformation syndrome first described by Danish anatomists in the seventeenth century. The heart malformation tetralogy of Steno-Fallot was first described by the Danish anatomist Niels Stensen (Nicolaus Steno) (1638–1686) in Thomas Bartholin’s Acta Medica &amp; Philosophica Ann. 1671 &amp; 1672 in 1673, but this was not discovered until 1942. Stensen’s description was built upon a dissection of a female fetus, which he made during his stay in Paris 1664–1665. We bring the first full Danish translation of Stensen’s Latin text and an analysis of his description in relation to his contemporaries and the present. Stensen describes three of the four elements of the tetralogy described in three adult patients by Fallot in 1888, namely ventricular septal defect, pulmonic stenosis and dexteriority of the aorta. The fact that Stensen does not mention the hypertrophy of the right ventricle may have two good reasons. Firstly, the difference between the wall thickness of the right and left ventricles is generally less pronounced in a fetus than after the birth and this would be expected even more in a heart malformation with overload on the right ventricle.Secondly, Stensen may have considered the right sided hypertrophy as merely a result of the three other elements of the tetralogy than as a malformation in itself.Stensen’s description reveals an impressive knowledge about the circulation of the blood in the heart of a fetus, and we speculate that he may have been the first in history to deliver such a precise description, not only of the anatomy and physiology of the tetralogy of Steno-Fallot, but also of the anatomy and physiology of the blood circulation in the fetal heart. Stensen’s fetus had several other malformations, i.e. cleft lip and palate, schisis of the abdomen and thorax and syndactyly of the second to fifth fingers on the left hand. We suggest that the fetus may have had acrofacial dysostosis 1 (Nager syndrome), which is caused by a mutation on chromosome 1q21.2.Likewise, Stensen’s mentor, the Danish anatomist Thomas Bartholin (1616–1680), was the first to describe a case report of the Bartholin-Patau syndrome in his Historiarum anatomicarum rariorum Centuria III &amp; IV in 1657, but this was not discovered until 1960, the same year as Patau and collaborators showed that this syndrome is caused by trisomy 13. We bring the first full Danish translation of Bartholin’s Latin text with an analysis in relation to his age and the present.

Georgius Agricola’s contributions to hydrology

Summary Georgius Agricola’s 1546 book De Ortu et Causis Subterraneorum (On the Source and Causes of What is Underground) was the first European work since antiquity to focus on hydrology and helped to shape the thought of Nicolaus Steno, Pierre Perrault, A.G. Werner, and other important figures in the history of hydrology and geology. De Ortu contains the first known expressions of numerous concepts important in modern hydrology: erosion as an active process, groundwater movement through pores and fissures, hydrofracturing, water-rock reaction, and others. The concepts of groundwater origins, movement, and nature in De Ortu were also the foundation for the theories of ore deposit formation for which Agricola is better known. In spite of their importance, most of Agricola’s contributions to the study of groundwater are unrecognized today because De Ortu , alone of his major works, has never been translated out of Latin and no existing vernacular summary of it is longer than two pages. This article presents the first detailed description of Agricola’s work on hydrology and discusses the derivation and impact of his ideas.

The "Capella Stenoniana" in Florence: the tomb of blessed Niels Stensen (1638-1686).

The "Capella Stenoniana" (Niels Stensen chapel) situated in the Basilica of San Lorenzo in Florence is the tomb of the anatomist and founder of modern geology Niels Stensen (1638-1686). It displays commemorative plaques and contains a sarcophagus with Stensen's mortal remains. The tomb of Blessed Stensen, whose canonization process is under way, is always covered with papers with requests for intercession, prayers and thanks written by pilgrims from throughout the world, among them pupils, students, professors and other academics. They come to the tomb to seek Stensen's intercession to obtain God's graces.