toe id ath Maik UP by $ Cornell University The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924012131458 THE PRODROMUS OF NICOLAUS STENO’S DISSERTATION CONCERNING A SOLID BODY ENCLOSED BY PROCESS OF NATURE WITHIN A SOLID i AN ENGLISH VERSION WITH AN INTRODUCTION AND EXPLANATORY NOTES BY JOHN GARRETT WINTER UNIVERSITY OF MICHIGAN “WITH A FOREWORD BY WILLIAM H. HOBBS UNIVERSITY OF MICHIGAN ;. o- New Bork ’ - THE MACMILLAN COMPANY LONDON: MACMILLAN AND COMPANY, LIMITED 1916 All rights reserved 7 HE volumes of the University of Michigan Studies are published by authority of the Executive Board of the Graduate School of the University of Michigan. A list of the volumes thus far published or ar- ranged for 1s given at the end of this volume. Anibersity of Michigan Studies HUMANISTIC SERIES VOLUME XI CONTRIBUTIONS TO THE HISTORY OF SCIENCE PART II. NICOLAUS STENO’S DISSERTA- TION CONCERNING A SOLID BODY ENCLOSED BY PROCESS OF NATURE WITHIN A SOLID THE MACMILLAN COMPANY NEW YORK - BOSTON - CHICAGO - DALLAS ATLANTA + SAN FRANCISCO MACMILLAN & CO., Limitep LONDON - BOMBAY - CALCUTTA MELBOURNE THE MACMILLAN CO. OF CANADA, Ltp. TORONTO Puatre V. Portrait oF Sreno IN THE Prrrt PaLace, THE PRODROMUS OF NICOLAUS STENO’S DISSERTATION CONCERNING A SOLID BODY ENCLOSED BY PROCESS OF NATURE WITHIN A SOLID AN ENGLISH VERSION WITH AN INTRODUCTION AND EXPLANATORY NOTES BY JOHN GARRETT WINTER UNIVERSITY OF MICHIGAN WITH A FOREWORD BY WILLIAM H. HOBBS UNIVERSITY OF MICHIGAN Netw Bork THE MACMILLAN COMPANY LONDON: MACMILLAN AND COMPANY, LIMITED 1916 All rights reserved h.374 36 | COPYRIGHT, 1916, By FRANCIS W. KELSEY, EDITOR. Set up and electrotyped. Published September, 1916. QE HOF Seely 1W1¢ Norwood ress J. 8. Cushing Co. — Berwick & Smith Co. Norwood, Mass., U.S.A. PREFACE THE task of preparing this translation of Steno’s Prodromus has been lightened by the generous help of several of my colleagues in the University of Michigan. To Professor W. H. Hobbs I am indebted for suggesting the work and for reading the entire manu- script, as well as for contributing a Foreword. Professor E. H. Kraus read in manuscript the section dealing with crystallography, and Professor E. C. Case gave helpful suggestions in questions of paleontology. A point in physics was clarified by Professor W. D. Henderson. To Professor J. B. Woodworth, of Harvard University, my thanks are due for permission to reprint the section entitled Zhe Interpreter to the Reader from his copy of the A. O. version, and for verifying certain references. Mr. Bernhard Berenson, of Florence, kindly furnished photographs of the portrait of Steno in the Pitti Palace, and of Duke Ferdinand II in the Uffizi, Dr. Fr. C. C. Hansen, of the University of Copenhagen, generously sent a photo- graph of the portrait of Steno as Vicar of Schwerin. But from the editorial side my greatest debt, and one I have especial pleasure in acknowledging, is to Dr. Vilhelm Maar, of the University of Copen- hagen, whose scholarly edition of Steno’s Ogera Philosophica has been of invaluable service. In addition to furnishing photographs of the portraits of Steno, Dr. Maar has given me, by letter, not only much information, but also warm encouragement. The recent publication of a facsimile edition of the Prodromus, by W. Junk (Berlin, 1904), and of the text, by V. Maar (Copen- hagen, 1910), has obviated the necessity of presenting the Latin text in connection with this translation. I am under much obligation to Mr. William H. Murphy, of Detroit, whose generosity has made possible this publication in the Humanistic Series. JOHN G. WINTER. ANN ARBOR, MICHIGAN, March 15, 1916. ForEwo RD INTRODUCTION: I. II. III. IV. Life of Steno The Writings of Steno Bibliography of the Prodromus CONTENTS Selected References TRANSLATION OF THE PRoDROMUS WITH EXPLANATORY NorTES ATTESTATIONS . EXPLANATION OF THE FIGURES INDEX PLATES PORTRAIT OF STENO IN THE PITTI PALACE PORTRAIT OF STENO AS VICAR OF SCHWERIN REPRODUCTION REPRODUCTION REPRODUCTION REPRODUCTION REPRODUCTION OF ORIGINAL TITLE PaGE. or First PaGE OF STENO’S FIGURES, I-13 OF STENO’S FIGURES, 14-19 OF STENO’s FIGURES, 20-25 PAGE 169 175 188 194 202 205 271 272 277 Frontispiece FACING PAGE 184 194 REPRODUCTION OF TAILPIECE (p. 76 of Original Edition published at Florence in 1669) vii FOREWORD THE ScIENCE OF THE PrRopromus or NicoLaus STENO In reading the Prodromus of Nicolaus Steno one should remember | that the essay was written near the middle of the seventeenth century, | when scientific observation was hardly thought of. All knowledge | concerning the causes of natural phenomena was generally supposed to have been given by God directly to man, and the message was strictly guarded by the church. Giordano Bruno, who denied that there had been a universal deluge, and who had brought forward evidence that a change had taken place in the distribution of land and sea, was burned at the stake for heresy. More than a century later, and a half a century after Steno wrote, de Maillet, in order to express his conviction that the rocks of the earth were marine deposits, thought it necessary to disguise his name in the anagram Tellzamed and to allow his views to be published only after his death. In view of these conditions Steno’s Prodromus is remarkable for its generally untrammelled reasoning, although the concluding pages of the essay are given over to a somewhat labored effort to prove that his views are .not incompatible with Scripture, and that the written word has supplemented his observation. It seems doubtful, however, that he would have escaped persecution had he not been a devout Catholic and, moreover, under the protection of a powerful | prince, the Grand Duke Ferdinand II. Some indication of the atmosphere of Florence in Steno’s time may be gained from Vin- centius Viviani’s certificate appended to the Prodromus and approving it for publication, “since I have recognized in it a perfectly sincere manifestation of the Catholic faith and of good morals, as in the very candid author, I have thought the same worthy of being entrusted to type” (p. 271). | Steno is the pioneer of the observational methods which dominate | in modern science, but he was destined to pass away and be almost forgotten before the methods which he used were to be adopted by students of science. If we except Leonardo da Vinci, who like Steno was a Florentine by adoption and who antedated him by a century 169 ie FOREWORD and a half, there was no writer upon natural science before the | eighteenth century that in accuracy of observation, in cogency of reasoning, or in discrimination of judgment might be compared with the “learned Dane.” In some measure Steno reflected, of course, the crude notions of his time. Thus we find him adopting, though apparently with some reserve, the doctrine of the four elements, fire, earth, air, and water. In the main, however, if we exclude the prolix introduction addressed “to the Most Serene Grand Duke” and the weak conclusion intended to prove the orthodoxy of his position, the Prodromus with but moderate changes may be made to harmonize with the science of the twentieth century. We must attribute it _ largely to the closeness of his observation of Nature and to his dis- _criminating judgment, that Steno was not lured into wild speculations, -aS were so many in his time. One of his statements might well be printed in large letters and placed upon the walls of our laboratories and lecture rooms, as a warning to those who undertake scientific investigation. “The nurse of doubts,” says Steno, “seems to me to be the fact that in the consideration of questions relating to nature those points which cannot be definitely determined, are not dis- tinguished from those which can be settled with certainty” (p. 213). How much trouble would be saved if to-day scholars had this point oftener in mind ! . The form of Steno’s essay is geometrical, and this is responsible for the almost unintelligible title and the correlation of subjects which, interpreted in the elaborate differentiation of twentieth century science, appear somewhat incongruous. As stated in the introduction, the Prodromus is divided into four parts. The first of these contains among other things an inquiry into the origin of fossils. The second part is stated to be: “Given a substance possessed of a certain figure, and produced according to the laws of nature, to find in the substance itself evidences disclosing the place and manner of its production.” In like geometrical form the third part discusses solids which are con- tained within solids. The concluding portion of the essay is largely a consideration of the prehistoric geological changes which Steno was able to read in the rocks of Tuscany. The broad outlines of the Cartesian conception of matter were adopted by Steno, who regarded a natural body as an aggregate of imperceptible particles subject to the action of forces such as proceed from a magnet, from fire, or sometimes from light. A fluid differed NICOLAUS STENO 171 from a solid in having its particles in constant motion and with- drawing from their neighbors, that is to say, changing their relative positions. Some of Steno’s greatest contributions to science lie in the field of crystallography, for he studied the growth of crystals and showed that those formed in the mountains must have developed in the same manner as crystals of niter separating from solutions in water. These grow, he said, by accretions of substance upon the surface of the crystal nucleus, and not as do plants and animals. The prevalent columnar form of crystals and the variation of their habit through the occurrence of faces of variable size, Steno ex- plained by the addition of substance on certain sides only of the growing crystal. The force which draws the substance out of the surrounding fluid he recognized to be inherent in the crystal itself, | and this crystallizing force he happily likened to what we should | to-day call the lines of force about a magnet. | It is hardly to be expected that, great as Steno was, he should in : his day have discovered the important fact of the orientation of the molecules of crystals, but he did point to the striking peculiarity of light refraction that distinguishes the crystal from amorphous sub- stances, such as glass. Steno was, however, the discoverer of the fundamental law of crystallography known as the law of constancy of interfacial angles. As usually stated, this law affirms that xo matter how much the faces of a crystal may vary im their size or shape, the interfacial angles remain constant, provided they are measured at the same temperature. The absolutely empirical veri- fication of this law was delayed until the invention of the reflecting goniometer in 1805. Barring the refinement of temperature varia- tions, it was amply verified by Rome de I'Isle with the simple goni- ometer which he invented in 1783. It is clear, however, that Steno more than a century earlier fully grasped the principle of the law, and gave it some sort of crude experimental verification. In the explanation of his figures, Steno says (p. 272): “Figures 5 and 6 belong to the class of those crystals which I could present in countless numbers to prove that in the plane of the axis both the number and the length of the sides are changed in various ways without changing the angles.” As a corollary to his deductions concerning the growth of crystals, Steno showed that so-called “phantom crystals” are no product of 172 FOREWORD the action of the larger crystal, but existed first and were enveloped through continued growth of the crystal nucleus. In the realm of geology we owe to Steno the first clear enuncia- tion of some of those great principles which to-day we assume to be axiomatic only because so much has been built upon them as a foundation. That rocks in the main result from sedimentation in water is thus expressed in the Prodromus (p. 219): “ The strata of the earth, as regards the manner and place of pro- duction, agree with those strata which turbid water deposits.” _ The reasons for this belief are most cogent: “The strata of the earth are due to the deposits of a fluid, (1) because the comminuted matter of the strata could not have been reduced to that form unless, having been mixed with some fluid and then falling from its own weight, it had been spread out by the movement of the same superincumbent fluid; (2) because the larger bodies contained in these same strata obey, for the most part, the laws of gravity, not only with respect to the position of any substance by itself, but also with respect to the relative position of different bodies to each other” (p. 227). It is further clearly shown how marine deposits may be distin- guished by their character from those deposits which are laid down in fresh water upon the continents, as well as from the ejectamenta of volcanoes. The origin of variation in the character of strata from place to place, and of the alternation of layers of different characters, are all discussed with a clear understanding of the actual conditions. The great principle that the order of superposition of. beds deter- mines the age of formations, is given its first expression (p. 230). “At the time when any given stratum was being formed, all the matter resting upon it was fluid, and, therefore, at the time the lowest stratum was being formed, none of the upper strata existed.” Likewise it is pointed out that sedimentary formations were either laid down in definite basins of deposition or were universal in their extent. The original horizontality of sedimentary formations is now regarded as one of the great fundamental principles of geology. Steno says of the strata “that the upper surface was parallel to the horizon, so far as possible ; and that all strata, therefore, except the lowest, were bounded by two planes parallel to the horizon. Hence it follows that strata either perpendicular to the horizon or inclined toward it, were at another time parallel to the horizon” (p. 230). NICOLAUS STENO 173 If strata are no longer in a horizontal position, it indicates, says Steno, subsequent disturbance of them; and this may be due either to uplift “by violent thrusting up of the strata,” or “spontaneous slipping or downfall of the upper strata after they have begun to form cracks, in consequence of the withdrawal of the underlying substance, or foundation ” (p. 231). These changes in position of the strata are according to Steno the chief cause of mountains, and he pretty clearly distinguishes three of the more important mountain types; namely, (1) block or fault mountains, (2) volcanic mountains, and (3) mountains of ero- sion. The relation of earthquakes to the formation of mountains is indicated with a much nearer approach to present beliefs than is to be found in any save Robert Hooke and comparatively recent writers. The fissures which form in the strata were recognized by Steno to be the passageways or channels for the movement of underground water, and for subterranean gases as well. These crevices are thus the places where veins of mineral are formed. The storehouses of the precious metals being brought about by natural processes, the foolishness of those who employ the divining rod for the locating of them is pointed out. An imperfect notion of the manner of replace- ment of one mineral by another seems to have been gained by Steno from his studies. In the description of the figures—a most important part of the essay —a clear conception is revealed of the relative order of age of strata, of the alternation of transgression and recession of the sea over the same places, and of the nature of a structural unconformity, whereby one set of strata comes to overlie another from which it differs in its lesser angle of inclination. Here Steno gives us the results of his careful field observations in the vicinity of Florence. His figures may, therefore, be regarded as the earliest geological sections ever prepared. Over the origin of fossils war had long been waged in Steno’s time. Like Leonardo, a century and a half before, Steno declared that fossils were petrified remains of plants and animals which had once existed. Steno’s activity in biological studies is brought out in his elaborate examination of the structure of the shells of mollusks. His descrip- tion of the subdivisions of the shells and the division of these into 174 FOREWORD filaments, and of the various surfaces formed by the aggregation of these filaments, is suggestive of the methods of modern histological science. He shows that the substance of the filaments is developed from a fluid exuded through the outer surface of the animal. The structure of pearls, and their relation to the growing mollusks, is discussed at considerable length. In treating the length of geological time, Steno was clearly ham- pered by the church doctrine of the time, to which he himself sub- scribed. Accepting as correct the Usher chronology of the Scriptures and the Noachian conception of the universal deluge, it is small wonder that Steno fell into error in evaluating geological time. “ There are those,” he said, “to whom the great length of time seems to destroy the force of the remaining arguments, since the recollec- tion of no age affirms that floods rose to the place where many marine objects are found to-day, if you exclude the universal deluge, four thousand years, more or less, before our time” (p. 258). He thinks it possible to affirm that the shells dug from the hill on which Volterra was built, were formed more than three thousand years ago. The remains of elephants and extinct animals which were found in the valley of the Arno, and which we now know crossed from Africa on a land bridge in Tertiary times, Steno was forced to regard as the mired pack animals which had been brought by Hannibal’s army on its way to besiege Rome. Now that the Latin text of Steno’s work has become available through republication, it seems opportune to make his argument accessible in English, and it is believed that Dr. Winter’s rendering of the learned Dane’s Prodromus, with annotations and with a brief account of his life and writings, will ube welcomed by students of natural science. Wm. Hersert Hosss. ANN ARBOR, Michigan, ; February, 1916. INTRODUCTION I. THE LIFE OF NICOLAUS STENO Nico.taus Sreno,! the son of a goldsmith, Steen Pedersen, was born in Copenhagen, January 10, 1638.? ‘From early childhood,’ he wrote in 1680, ‘the association with those of my own age had little charm for me. For I was constantly in poor health from my third to my sixth year, and was accordingly under the continual care of my parents and older friends. As a result, I grew to prefer the conversation of older people, especially when they spoke of religion, to the frivolous chatter of younger companions. In my journeys, also, I kept away, as much as pos- sible, from idle and dangerous people and sought friendship with those who had won repute through their upright life or their learning.’ After acquiring a thorough training in ancient and modern languages and mathematics in the grammar school of his native city, Steno entered its University in 1656, where he took up the} study of medicine and had among his instructors the distinguished scientists Thomas Bartholin, Borrichius (Ole Borch), and Simon , as 1 Niels Steensen, the Danish form of the name, in accordance with the learned custom of his day was Latinized by its bearer as Nicolaus Stenonis. The current form, Steno, is due to the mistaken idea that Stenonis was a genitive case. The spelling in French is Sténon and in Italian Stenone. Cf. Vilhelm Maar, WVicolat Stenonis Opera Philosophica (2 vols., Copen- hagen, 1910), Vol. I, p. 1, note 1. According to custom, Steno took his surname from his father’s given name; see Plenkers, Der Dane Niels Stensen, Ein Lebensbild (Freiburg im Br., 1884), p. 3, note I. The sources of Steno’s life, consisting chiefly of letters and unpublished manuscripts, are given by Plenkers, of. czt., pp. v, vi. To Plenkers, Wichfeld (Z2riudringer om den danske Videnskabsmand Niels Stensen in Historisk Tidsskrift, 3 Raekke, 4 Bind, Kjgbenhavn, 1865, pp. I-109) and Maar (Vol. I, pp. i-xi) I am chiefly indebted for the biographical material here given. 2 The Encyclopedia Britannica, in its eleventh edition, presents an inadequate biography of Steno in seventeen lines, and incorrectly gives 1631 as the date of his birth. The ninth edition contains no biographical notice. The error appears also in the account by Chéreau in the Dictionnaire Encyclopédique des Sciences Médicales (Troisigme Série, Tome Onziéme, Paris, 1883, pp. 689-691), in which January 1, 1631, is given as the date. 8 Defensio et plenior elucidatio epistolae de propria conversione, Hannover, pp. 18, 19; quoted by Plenkers, Véels Stensen, pp. 3, 4- 175 176 INTRODUCTION Paulli. In all probability he took no degree,! for the times were troublous, and Steno, like other students, helped defend Copenhagen during its siege by Carl Gustav, king of Sweden. In 1660 Steno went to Amsterdam to continue his studies and was warmly received by Gerard Blaes, the anatomist, to whom he had been recommended by Bartholin. His stay of four months in Amsterdam was made memorable by the discovery on April 7, 1660, of the parotid duct, which is still known as the ductus Stenontanus? Blaes, however, claimed the discovery for his own, and a warm con- troversy ensued, in which Steno defended himself with ability and dignity. On April 22, 1661, Steno wrote to Thomas Bartholin from Leyden: * ‘Since you urge me in your letter to publish an account of the exterior salivary duct, I am constrained to explain to you briefly the envy which this bit of a discovery (zzvendzuncula) has won for me, and also the result of this envy; not with the purpose of seeking fame in trifles,t but in order to free myself from the hateful charge of stealing what does not belong to me. For I am sorry that the necessity has been laid upon me of being forced to say much upon a subject of no importance, or else to submit to the base brand of shame. A due consideration of the matter will show that it is not worth making much ado about. For a similar duct® had been pre- viously discovered, and even the very duct in question had been observed by Casserius® although he called it a muscle.... Since, however, the charge imputed to me by reason of that duct does not 1 Wichfeld, of. czt., p. 6, says that Steno went to Amsterdam in 1660 as “Dr. physices.” He is followed by de Angelis in Bzographie Universelle (Michaud ; Mouvelle Edition, Tome Quarantidime, p. 209), by Chéreau in the Dectzonnaire Encyclopédique des Sctences Médicales (p. 689), and by Hughes in ature (Vol. 25, 1882, p. 484). Plenkers (Viels Stensen, p. 11, note 5) gives good evidence for believing that no degree had been conferred, and Maar (Ofera Philosophica, Vol. I, p. ii) implies as much. 2Jt appears that the parotid duct was observed independently by Needham in 1655, but his results were not published until 1667 (Maar, of. czt., Vol. I, p. iii). Steno’s treatise bears the following title and date: De Glandulis Oris et Novis Inde Prodeuntibus Salivae Vasis, Lugd. Batav. Anno 1661. It is printed by Maar, of. c7t., Vol. 1, pp. 9-51. 8 De Prima Ductus Salivalis Extertoris Inventione et Bilsianis Experimentis, Lugd. Batav. Ao (anno) 1661, 22 ap. (Aprilis). Printed by Maar, of. czt., Vol. I, pp. 1-7. 4 In mustaceo laureolam quaeram means literally ‘look for a laurel-wreath in a cake.’ Cicero uses the proverb in writing to his friend Atticus, V. 20, 4. 5 Ductus Whartonianus, for which see Adenographia...Auctore Thoma Whartono, Lon- don, 1656, c. XXI, p. 129; Maar, of. czt., Vol. I, p. 222. 6 De Vocis Auditusgue Organis Historia Anatomica, Ferrara, 1600, tab. V, p. 27, d, ac- cording to Maar, of. czt., Vol. I, p. 222. LIFE OF STENO . 177 permit me to keep silent, I shall tell you the entire affair, as pupil to preceptor, and shall leave the decision to your judgment. ... ‘It is a year now since I was hospitably received by Blaes. After waiting three weeks for a chance to secure anatomical material, I asked the distinguished man whether I might be permitted to dis- sect with my own hand such material as I could buy for myself. He gave his consent, and fortune so favored me that in the first sheep’s head, which I had bought on April 7 and was dissecting alone in my room, I found a duct which, so far as I knew, had been described by no one before. I had removed the skin and was pre- paring to dissect the brain when I decided to examine first the ducts. With this end in view I was exploring the courses of the veins and arteries when I noticed that the point of my knife was no longer closely confined between tissues but moved freely in a large cavity, and presently I heard the teeth themselves resound, as I thrust my knife forward. ‘In amazement at the discovery I called in my host (Blaes) that I might hear his opinion. First he ascribed the sound to the violence of my thrust, then resorted to calling it a freak of Nature, and finally referred to Wharton. But inasmuch as that did not help, and the ducts, which had been handled carelessly, allowed no further inves- tigation, I decided to examine them another time more carefully. I succeeded, although not so well, a few days later with a dog’s head. Since its affinity to the inferior duct indicated the function of the one I had found, I told Jacob Henry Paulli, my intimate friend, that I had discovered a salivary duct, and I added a description of it. But since I knew that something like it had been discovered before and could not determine whether this identical duct had been ex- amined, I remained silent until I could find opportunity to consult Sylvius about it. After he had heard my account he determined to seek the duct in man, and having found it he demonstrated it to spectators on several occasions.’ Steno then proceeds to show that Blaes’s brother, who was in Amsterdam at the time and was thoroughly conversant with the discovery, had accredited it to Steno in letters to Eysson, Professor 1 See p. 176, note 5. 2 Maar, op. cit., Vol. I, pp. 3-5- For a convenient description of the duct and the relation of Steno’s work to that of Richard Hale see de Angelis, Béographie Universelle (Michaud), Nouvelle Edition, Tome Quarantieme, p. 209. 178 INTRODUCTION at Groningen. And furthermore, while Blaes mentioned the duct in his Medicina Generals, which appeared in 1661, a year after the dis- covery, he could account for neither the beginning nor the end of the duct.’ Meanwhile Steno had gone to Leyden, where he remained from : 1660-1664. Here he worked under van Horne, the surgeon, and Franciscus de la Boé Sylvius, the distinguished anatomist who dis- covered the Sylvian aqueduct. Among his intimate friends were men of widely differing attainments. The brilliant young Dane seems, in fact, to have had a genius for friendship. No fellowship could fail to stimulate reflection which included such men as Jan Swammerdam, the naturalist, whom Steno had previously known at Amsterdam; Borrichius, his old teacher, who had come from Copenhagen; Matthias Jacobaeus, Professor at Copenhagen, and later Bishop of Aarhus in Jutland; Peter Schumacher, who later became Count Griffenfeldt and High Chancellor of Denmark; Jacob Golias, Professor of Arabic at Leyden, and Baruch Spinoza, the philosopher, who was then living at Rijnsburg, a suburb of Leyden. But great as the influence of these men was, it was, perhaps, less telling for his subsequent spiritual development than the religious tolerance which Holland alone of European coun- tries then afforded.? While pursuing his anatomical studies in Leyden, Steno learned of the death of his step-father,? and thereupon returned to his native city. Disappointed in his expectation of gaining a professorship, Steno set out in the same year, 1664, for Paris, where he and Swammerdam lived with the naturalist Thévenot. It was in the latter’s house that Steno delivered his discourse on the anatomy of the brain. This treatise shares with the Prodromus the virtues of 1 Maar, of. cit., Vol. I, p. 223; Plenkers, Viels Stensen, pp. 12-14, and Wichfeld, Ey7n- aringer om Niels Stensen, pp. 7, 8. ? Maar, Opera Philosophica, Vol. 1, pp. iv-v. 8 Steno’s father died in 1644, and his mother, Anna Nilsdatter, had contracted a second marriage with Johannes Stichman. Her death followed closely upon that of the latter. See Plenkers, Wels Stensen, pp. 3, 22, 25. 4 Discours sur Panatomie du cerveau, first printed in Paris in 1669; it is reprinted by Maar, of. cét., Vol. II, pp. 3-35. Jacques Bénigne Winslow, a grand-nephew of Steno, and himself a scientist of note, was so impressed by the treatise that he printed it in full in his Exposztion Anatomique (Paris, 1732), pp. 641-659. The preface of the work closes with this remarkable acknowledgment : “Je finis en avertissant avec une sincere reconnoissance, que le seul Discours de feu M. Stenon sur l’Anatomie du Cerveau, a été la source primitive et le modele general de toute LIFE OF STENO 179 lucidity and scientific objectivity. At a time when fantastic meta- physics were rife, Steno trusted only to induction based upon experi- ment and observation. Combating the theories of Descartes and Willis in particular, the author prefaces his discourse with the candid admission : “Au lieu de vous promettre de contenter vostre curiosité, touchant l’Anatomie du Cerveau; ie vous fais icy une confession sincere et publique, que ie n’y connois rien. Ie souhaiterois de tout mon coeur, d’estre le seul qui fust obligé 4 parler de la sorte; car ie pourrois profiter auec le temps de la connoissance des autres, et ce seroit un grand bon-heur pour le genre humain, si cette partie, qui est la plus delicate de toutes, et qui est sujette 4 des maladies tres- frequentes, et tres-dangereuses, estoit aussi bien connué, que beau- coup de Philosophes et d’Anatomistes se l'imaginent. II y en a peu qui imitent lingenuité de Monsieur Sylvius, qui n’en parle qu’en doutant, quoy qu'il y ait travaillé plus que personne que ie con- noisse. Le nombre de ceux a4 qui rien ne donne de la peine, est infailliblement le plus grand. Ces gens qui ont |’affirmative si prompte, vous donneront l'histoire du cerveau, et la disposi- tion de ses parties, avec la mesme asseurance, que s’ils avoient esté presens 4 la composition de cette merveilleuse machine, et que sls avoient penetré dans tous les desseins de son grand Architecte.” 4 Paris, however, did not hold Steno long. In the summer of 1665 we find him in Florence,? where he was soon attached to the court of the Grand Duke Ferdinand II. Upon the recommendation of Thévenot and Viviani, Steno was appointed physician to the Grand Duke, with a house and pension. He was also given a position in the hospital of Santa Maria Nuova. This patronage, gratefully acknowledged in the present treatise, and the opportunity for travel ma conduite dans les travaux Anatomiques. Jel’ai inseré dans le Traité de la Téte, croyant faire plaisir au Public de lui communiquer de nouveau cette Piece, qui étoit devenue rare, et qui renferme beaucoup d’excellens avis, tant pour éviter le faux et l’imaginaire, que pour découvrir le vrai et le réel, non seulement par rapport & la structure et aux usages des parties, mais aussi par rapport & la maniere de faire les Dissections et les Figures Anatomiques.” The first and only complete edition of L’Autobiographie de Jacques Bénigne Winslow is that of Maar, Copenhagen, 1912. I am indebted to it for the foregoing passage, p. xxiv. 1 Maar, Opera Philosophica, Vol. Il, p. 3- 21 have followed Maar, Opera Philosophica, Vol. 1, p. vi. Plenkers, Wiels Stensen, p. 30, and Wichfeld, Zrzndringer om Niels Stensen, p. 17, give 1666 as the date of Steno’s arrival in Florence. 180 INTRODUCTION which his position at court afforded him, made possible Steno’s scientific researches. Now followed the happiest and most productive period of Steno’s life. Ferdinand II, although a weak prince, was a generous patron of art and science. The Accademia del Cimento, founded in 1657 ‘by Leopold de’ Medici, the brother of Ferdinand, was the center of a learned group including Vincenzo Viviani, the pupil and biographer of Galileo, Francesco Redi, poet and naturalist, Carlo Dati, the scientist, and Lorenzo Magalotti, the versatile secretary of the society. ‘I have the honor, Redi wrote to Athanasius Kircher,! ‘to serve at a court where distinguished men gather from all parts of the world. In their wanderings they bring and seek in exchange the fruits of high endeavor, and so warm is their welcome that they fancy themselves transported to the mythical gardens of the Odyssey.’ Through the influence of Maria Flavia del Nero, a nun who had long been in charge of the apothecary connected with Santa Maria Nuova, also Lavinia Felice Cenanni Arnolfini, the wife of the ambassador from Lucca, and Emilio Savignani, a Jesuit priest, Steno was induced to embrace Catholicism. He was deeply reli- gious by nature, and there can be no question about the sincerity of his conversion. His seriousness as a lad, and the impression made upon him by the religious tolerance in Holland, have been mentioned. Furthermore, since meeting the eloquent Bossuet in Paris he had been pondering deeply the question of Catholicism versus Protestantism.? He was finally received into the Church, December 8,1667. Five days later Viviani wrote to Magalotti, who was then in Flanders: ‘My very dear friend, N. Steno, who lacked only this to make him adorable, so to say, has turned back to life on the day of the dead,’ in that he has confessed the Catholic faith. His decision to take the final step gave great joy to His Highness (Ferdinand IJ) and all his friends. On the day of the Immaculate Conception, 1 Quoted by Plenkers, Véels Stensen, p. 31. * The question of Steno’s conversion is treated at length by Plenkers (/Viels Stensen, pp. 36-50), who includes in his account many of the letters that passed between Steno and bis friends. The reasons which induced Steno to take this step were set forth by him in Epistola de propria conversione (Florence, 1677) and Defensio et plenior eluctdatio epistolae de propria conversione (Hannover, 1680). ; 3 All Souls’ Day, November 2, is Giorno de’ Mort? in Italian. LIFE OF STENO 181 after he had finally declared his conversion before the Nuntius also, he received a letter from his King, which he called an invitation, with the command to return as soon as possible. An annual pen- sion of four hundred scudi was promised him from the day of his departure. There are no further stipulations, and he can expect an increase of this amount. Still, he is unwilling to begin the journey until he has learned whether His Majesty will support him in this way in spite of his change of belief. Inasmuch as we cannot hope that this will be the case, we have the prospect of keeping him with us.’ ! According to Blondel? Steno wrote to Frederik III informing him of his change of belief. While these negotiations were in progress Steno composed his Prodromus* (1668). The original plan of writ- ing the treatise in Italian was given up in favor of Latin, and when the remarkable essay appeared it was under the title Mcolaz Stenonts De Solkdo Intra Solidum Naturaliter Contento Dissertationts Pro- dromus. It was printed at Florence, in 1669, with the full sanction of the papal authorities, among whom were his influential friends, Redi and Viviani. : The Prodromus was intended as a preliminary statement of prin- ciples which the author expected to elaborate more fully in a later, comprehensive work, which is referred to throughout as the Disserta- tion. The larger work, however, never appeared, probably because 1 Quoted by Plenkers, Wzels Stensen, p. 5. This order of Frederik III, dated 19 October, 1667, is still preserved in Copenhagen. Compare of. c7t., note I. 2 Les Vies des saints pour chaque jour de l'année, Paris, 1722, p. 738. 3 The use of the word Prodromus to designate a treatise preliminary to a larger work is not found in classical Latin. The Mew Oxford Dictionary amply illustrates its occurrence in English, but the examples are from works subsequent to Steno’s time. Francis Bacon (1561- 1626) employs the word in the /nstauratio Magna, Prodromi sive Anticipationes Philosophiae Secundae (edition of Spedding, Ellis, and Heath, Vol. V, p. 182). Larousse, s.v. Prodrome, not only gives the best definition of the word as used by Steno, but also cites an excellent example of a writer whose accomplishment, like Steno’s, fell short of his original expectation : “Ce mot a été employé pour désigner une préface, une introduction, un discourse prélimi- naire; mais, dans sa signification la plus généralement acceptée, il est le titre méme d’un ouvrage destiné a préparer d'autres écrits dont il donne l’idée et auxquels il prépare le lecture. Il a été fait des livres de ce genre sur les matiéres théologiques et philosophiques. II en existe aussi qui sont relatifs aux sciences exactes et naturelles. L’un des plus remarquables est celui que Candolle a publié sous ce titre: Prodrome du systéme du regne végétal (Paris, 1824 et suiv. in 8%°). Ce célébre botaniste avait d’abord congu le plan d’un ouvrage extréme- ment vaste, qu’il intitula: Systéme naturel du régne végétal, et dont il fit paraitre deux volumes (1818-1821, in 8%°) ; mais, comprenant que la vie d'un homme ne se suffirait pas 4 remplir ce plan, il y renonga et fit son Prodrome, recueil déja fort vaste, présentant le répertoire des ordres, des genres, des espéces du régne végétal, et qu’il ne put terminer.” a 182 INTRODUCTION \Steno’s interest in geology had meanwhile given way to his interest in theology! Brief as it is, the Pvodvomus remains one of the most noteworthy contributions to the science of geology, and especially the geology of Italy. Steno’s habits of observation, analysis, and in- duction resulted in an enlightened exposition of geology considered from the petrological, palzontological, and stratigraphical point of view, at a time when many of his contemporaries were still satisfied with some of the absurdities of metaphysical speculation.2 Steno’s work, von Zittel remarks,’ “already contained the kernel of much that has been under constant discussion during the two centuries which have passed since his death; and if one reads the most recent text-books of geology, it will be evident that science has not yet se- curely ascertained the share that is to be assigned to subsidence, to upheaval, to erosion, and to volcanic action in the history of the earth’s surface conformation in different regions.” The journey to Denmark was not undertaken until a year after Steno’s conversion, and then by a circuitous route. After visiting Rome, Naples, and Murano, he reached Innsbruck in May, 1669, Vienna and Prague in the late summer of the same year, and finally Amsterdam in the spring of 1670. Meanwhile Frederik III had died February 2, 1670, and Steno remained in Holland. Upon learning of the serious illness of his patron Ferdinand II he departed at once for Florence. When he arrived (1670), Cosimo III had al- ready succeeded his father as Grand Duke of Tuscany. But the change in rulers brought no change in the warmth of Steno’s wel- come. Under Cosimo he arranged the minerals in the Pitti Palace, and continued his studies in geology. In the Pitti Palace is a series of portraits of distinguished men who were associated with the Court of Ferdinand II and Cosimo III. 1The Prodromus was Steno’s last scientific work of note. After his conversion (cf. p. 180) his interest in science rapidly waned. Leibnitz, who came to know and esteem Steno Jater in Hannover, in letters to Conring expresses deep regret that Steno had abandoned his earlier studies. See Gerhardt, Die philosophischen Schriften von G. W. Leibniz (Vol. I, Berlin, 1875), p. 185, and especially p. 193: “ Stenxonium Episcopum doleo nunc a physiologicis studits avert? ad theologica vel ideo quia in his facilius quam in illis habebit parem.” ? A striking instance of this is Kircher’s Mundus Subterraneus, Amsterdam, 1665. Com- pare Maar, Om Faste Legemer, Copenhagen, 1902, p. ii ff. 8 History of Geology and Paleontology, Eng. trans. (London, 1go1), p. 27. Compare Huxley, Vature, Vol. 24 (1881), p. 453; A. von Humboldt, Zssaz Géognostigue sur le Gisement des Roches dans les deux Hémispheres (Paris, 1823), p. 38; Cosmos, Eng. trans. (London, 1852), Vol. 2, pp. 347-348; M. J. P. Flourens, De la Longévité humaine et de la Quantité de Vie sur le Globe (Paris, 1855), pp. 211-215. LIFE OF STENO 183 Among these is a portrait of Steno, by an unknown painter, evidently made in the period when the Prodromus was composed; this is reproduced in our Plate V. On the recommendation of Count Griffenfeldt,! Christian V invited Steno to the Professorship of Anatomy in Copenhagen. The royal order, dated February 13, 1672, is still preserved in Copenhagen, and reads: ‘Know that by special royal grace and favor We have allowed you, until further gracious increase, four hundred reichsthaler a year. This pension shall date from the time of your arrival here. For it is our gracious command and will that you undertake at once your journey to our Kingdom of Denmark, in order to be here as soon as possible. You will comply in humble obedience.’? Steno’s reply to Count Griffenfeldt is dated April 26: ‘I thank your Excellency most humbly for your good will to me and wish with all my heart that God may grant me to prove to you, one day, my gratitude and willing service. I suppose that your Excellency already knows the reason why my answer is so late in arriving. For the letters containing the orders of His Royal Majesty did not reach Holland until April 3. From there they were for- warded to me yesterday, the twenty-fifth of April. I humbly ask you therefore to excuse my delay to our most gracious Lord and King. This morning I went to the Grand Duke to tell him of the command of His Royal Majesty, and I hope to receive leave for my final departure within a few days.’* Steno arrived in Copenhagen July 3, 1672. His notable address on the reopening of the Theatrum Anatomicum* was as mucha valedictory as an inaugural, for it marks the close of his scientific career. Hesoon became involved in religious controversies which made his tenure so disagreeable that he yearned for the old life at Florence. Accordingly, he resigned his position in the summer of 1674, and set out for Florence, visiting the Catholic Duke of Hannover, Johann Friedrich, on the way. Thence he came back to Amsterdam before proceeding to Italy. Upon hisarrival in Florence, late in the year 1674, he was appointed tutor to the son of Cosimo ITI, and thenceforth gave up natural science, for which his keen powers 1 See p. 178. 2 Quoted by Plenkers, Mzels Stensen, p. 91. 3 Plenkers, of. c7t., p. QI. 4Printed by Maar, Opera Philosophica, Vol. II, pp. 249-256. 184 INTRODUCTION of observation and analysis so admirably fitted him, in order to devote himself to questions of education and theology. In 1675 Steno took Holy Orders; in the following year (Septem- ber 14, 1676), Pope Innocent XI rewarded his zeal in attempting to convert his former friends! and co-religionists by appointing him Bishop of Titopolis? zz partibus infidelium, and Apostolic Vicar of Northern Germany and Scandinavia. In consequence, toward the end of 1677, he took up his residence in Hannover. An account preserved by Manni* gives a graphic picture of the austere life Steno’s devotion now induced him to lead: ‘The prelate lived and dressed as though he were the poorest person in the world. His position could only be inferred from his ecclesiastical garb, and even this was only serge. For he would not take the robes of his predecessor although they were offered to him at a low price. And notwithstanding the Duke made him an ample allowance to enable him to live as became his rank, he gave everything to the poor. For them he sacrificed everything. And he did this as long as we knew him. He even gave the gold necklace with a medallion containing a portrait of the Duke—he had received it on his second return from Denmark to Rome by way of Hannover *— to a friend with the injunction that it be bestowed upon the poor. When he had nothing else he sold his silver crucifix and costly bishop’s ring to relieve the distress of others.’ Upon the death of Johann Friedrich, in 1679, and the accession of his Protestant brother, Duke Ernst August, Steno was forced to withdraw to Munster. Here he was appointed Suffragan Bishop to Ferdinand, Baron von Fiirstenberg, the Bishop of Munster (1680). The latter died in 1683, and was succeeded by Archbishop Maxi- milian Heinrich. Steno had opposed his election and refused to celebrate mass in honor of the event. He therefore withdrew to Hamburg, where his self-imposed poverty and his asceticism alienated the Catholics themselves. They threatened to cut off his nose and ears, to drive him from the city, and even to kill him. In his 1Plenkers, /Véels Stensen (pp. 122, 123), quotes, among other letters, an interesting appeal to Spinoza. The latter did not reply. 2 An old bishopric in Isauria. 8 Vita del letteratissimo Mons. N. Stenone (Florence, 1775), p. 229; quoted by Plenkers, Niels Stensen, p. 131. 4 This statement is inexact; Steno did not go to Denmark in 1670, and in 1674 his objective was Florence, not Rome. Pruare VI. Portrait oF STeENo as VicaR OF SCHWERIN, LIFE OF STENO 185 trouble he began to long for the peace and friendships of Italy,! and was preparing to return when the missionary post at Schwerin was offered to him. He accepted it in 1685 as a call to further service. But the change meant only increased fasting and abject poverty, to which he succumbed November 26, 1686. At the request of Cosimo ITI Steno’s body was taken to Florence and laid in the famous San Lorenzo. The physical change which Steno’s self-denial entailed is strikingly shown in his portrait as Vicar of Schwerin. The original, by an un- known artist, is still in Schwerin. Until recently it was his only known portrait. An excellent copy, reproduced in our Plate VI, is in possession of the Anatomical Institute of the University of Copenhagen. On the walls of the cloister of San Lorenzo there is to-day a medallion portrait of Steno, surrounded by a marble wreath, with the following inscription, in black letters, beneath it: NICOLAI - STENONIS - IMAGINEM - VIDES - HOSPES QVAM - AERE - COLLATO - DOCTI - AMPLIVS « MILLE EX + UNIVERSO - TERRARUM - ORBE « INSCULPENDAM CURARUNT - IN - MEMORIAM - EJUS - DIEI- IV - CAL - OC- TOBR - AN: M-D- CCC - LXXXI- QUO - GEOLOGI - POST - CON VENTUM - BONONIAE - HABITUM « PRAESIDE - JOANNE CAPELLINIO - EQUITE « HUC - PEREGRINATI « SUNT - AT- QUE - ADSTANTIBUS - LEGATIS - FLOR - MUNICIPII « ET R - INSTITUTI - ALTIORUM - DOCTRINARUM - CINERES VIRI - INTER - GEOLOGOS - ET - ANATOMICOS - PRAE- STANTISSIMI - IN: HUJUS - TEMPLI - HYPOGEO : LAUREA CORONA - HONORIS - GRATIQUE - ANIMI - ERGO - HONE- STAVERUNT The medallion portrait is by Vincenzo Consani. Plenkers (WVzeds Stensen, p. 88) quotes the inscription, but does not divide it properly into lines. My own transcript was made in Florence June 20, rgrt. The Latinity of the inscription is open to criticism; ALTIORUM in line 9 should be aLTiaRuM, and the hyphens at the ends of lines 4, 7, 10, I2 are not in accordance with ancient usage. I add a trans- lation: - 1Indicated in the letters to Madame Arnolfini (Plenkers, Vzels Stensen, p. 178). 186 INTRODUCTION ‘Friend, you behold the likeness of Nicolaus Steno. To it more than a thousand men of learning, from all parts of the world, con- tributed. They made provision for the carving of it in memory of this day, the twenty-eighth of September, in the year 1881, when the Geologists, after the Congress at Bologna, under the Presidency of Cavaliere Giovanni Capellini, journeyed hither, and in the pres- ence of delegates representing the City of Florence and the Royal Institute of Higher Studies, in the cloister of this church, as a tes- timonial of respect and gratitude honored with a laurel crown a man of surpassing distinction among Geologists and Anatomists.’ The official account of the events recorded in the inscription is in itself a commentary of sufficient interest to warrant reprinting here, particularly because of its estimate of the value of Steno’s contribution to geology :1 Ils allérent en suite rendre hommage aux restes de Sténon qui reposent dans une tombe de plus modestes, dans la crypte souter- raine de la chapelle des Médicis, 4 San Lorenzo. Les chanoines de la Basilique se tenaient, pour les recevoir, au pied de l’escalier qui descend dans la crypte. La, M. le président Capellini invita 4 prendre la parole l’éminent représentant des études d’archéologie préhistorique, M. Waldmar Schmidt, de Copenhague. Notre savant confrére s’exprima en ces termes: “ Messieurs, Au moment ot. les membres du second Congrés géo- logique international sont réunis dans la célébre église de San Lorenzo, devant la tombe de Nicolas Sténon, vous permettrez, je Yespére, au seul représentant du pays ot est né Sténon, d’exprimer au noms de ses compatriotes les plus chaleureux remerciments a la ville de Florence pour l’hommage qu'elle a rendu A leur concitoyen. “Comme vous le savez, 4 une époque ot les sciences naturelles n’étaient pas encore sorties de leur premiére enfance, Nicolas Sténon a jeté les fondements de la géologie; et par ses études, par ses observations, par son génie perspicace, il est arrivé a énoncer, sur divers points de la science, des vues dont les géologues de notre siécle, aprés tant de nouvelles recherches, ont reconnu |’exactitude. “Sténon était né en Danemark et c’est 14 qu'il fit ses premiéres ' Congres Géologigue International . .. Compte Rendu de la 2me Session, Bologne, 1881, Pp- 249-251. See also the brief account in Bolletino del R. Comitato Geologico d’ Italia, vol. 12 (1881), pp. 379, 380. LIFE OF STENO 187 études. Mais c’est en Italie qu’iil a accompli ses merveilleuses découvertes et posé les bases de la géologie. II y fut regu avec cette splendide hospitalité qui nous a nous mémes accueillis partout d’abord 4 Bologne, aujourd’hui a Florence. “L’Italie fut sa seconde patrie, et ses restes mortels reposent dans ce temple magnifique, dans lequel on admire les ceuvres des plus grands artistes du monde. “Quand Sténon abandonna le Danemark pour venir se fixer dans ce beau pays, la science géologique ne déserta pas avec lui la patrie scandinave, “Ne dois-je pas, Messieurs, vous rappeler 4 cette occasion que si le Danemark a eu Sténon, un autre pays scandinave, la Suéde, a eu Linné. Comme l'un avait établi les fondaments de la stratigraphie, l'autre posa les bases de la géologie physique. . .. Vous me per- mettrez donc, Messieurs, de joindre 4 mes remerciments pour la ville de Florence et son syndic qui nous ont fait un si magnifique accueil, l’expression de ma reconnaissance pour celui qui par un beau travail a fait connaitre, je ne dirai pas le nom de Sténon qui était déja assez connu, mais sa vie, son origine et son pays natal: toute ma gratitude a M. Capellini, auteur de la Vie de Sténon et président du deuxieme Congrés international de géologie a Bologne.” Il (Capellini) ajoute que son but était de faire mieux connaitre ce grand homme dont le souvenir doit étre sacré pour tous les géo- logues, et sur la tombe duquel il est heureux de tendre la main a M. W. Schmidt, afin de reserrer entre l’Italie et le Danemark les liens d’affection que rappelle cette illustrée mémoire. . . . Le soir, le cercle philologique, le cercle des ingénieurs et le club alpin ouvrirent gracieusement leur salles aux congressistes. Mais avant de se rendre a ces amiables invitations, ils furent conviés 4 un diner 4 l’hdtel Minerva par le président Capellini, et, aprés, une souscription fut ouverte par ses soins pour placer sur le tombe de Sténon une pierre dont l’inscription rappellerait a la fois les glorieux titres scientifiques du célébre Danois, et la visite faite 4 sa tombe par les membres du Congrés géologique international. . . . II. THE WRITINGS OF STENO Steno’s published works may be grouped under three heads: Anatomy, Geology, and Theology. The scientific treatises have all been reprinted by Maar, Opera Phtlosophica (2 vols., Copenhagen, IgI0); no complete edition of his many interesting letters, and of his theological writings, has yet appeared. The following list, compiled from Maar and Plenkers, gives the full title of each published work, its date, and place of original publication. In the case of the scientific treatises references are given also to Maar’s edition. I. ANATOMY 1. a. Disputatio Anatomica de Glandulis Oris et Nuper Obser- vatts inde Prodeuntibus Vasts Prima. Leyden, 1661 (July 6). 6. Disputatio ... Secunda. Leyden, 1661 (July 9). These two articles appeared together in: De Glandulis Oris et Novis earundem Vasis Observationes Ana- tomicae. Leyden, 1661. Printed by Maar, Vol. I, pp. 9-51 (Number II). 2. Observationes Anatomicae, Quibus Varia Oris, Oculorum, et Narium Vasa Describuntur, Novique Salivae, Lacrymarum et Muct Fontes Deteguntur, et Novum Nobilissimi Bilstt de Lymphae Motu et Usu Commentum Examinatur et Rejicitur. Leyden, 1662. This volume includes four treatises: a. De Glandulis Oris, etc. pp. 1-54; a reprint of the two Dis- putationes. Maar, Vol. I, pp. 9-51 (No. II). 6. Responsio ad Vindicias Hepatis Redivivi, Qua Tela, Quae in Praesidem Celeberr. Dn. Johannem van Horne direxerat Clar. Antonius Deusingius, a Thestum Authore Excipiuntur, et Evanida Ostenduntur. Pp. 55-78. This treatise bears the date 28 November, 1661. Maar, Vol. I, pp. 59-73 (No. IV). 188 THE WRITINGS OF STENO 189 6. De Glandulis Oculorum Novisque earundem Vasis Observa- teones Anatomicae, Quibus Veri Lacrymarum Fontes Deteguntur. Pp. 79-100. Maar, Vol. I, pp. 75-90 (No. V). ad. Appendix de Narium Vasis. Pp. 101-108. Maar, Vol. I, pp. 91-97 (No. VI). 3. Apologiae Prodromus, Quo Demonstratur, Judicem Blasianum et Ret Anatomicae Imperitum Esse, et A Lfectuum Suorum Servun. Leyden, 1663. Maar, Vol. I, pp. 143-154 (No. XIII). 4. De Musculis et Glandulis Observationum Specimen Cum Lpistolis Duabus Anatomicis. Copenhagen, 1664. The De Mus- culzs, etc., is printed by Maar, Vol. I, pp. 161-192 (No. XV). _ The first of the two letters was written to Willem Piso, and is en- titled De Anatome Rajae Epistola. Dated April 24, 1664, Copen- hagen. Pp. 48—70.: Maar, Vol. I, pp. 193-207 (No. XVI). The second was written to Paul Barbette, and is entitled De Vitelli in Intestina Pulli Transitu Epistola. Dated June 12, 1664, Copen- hagen. Pp. 71-84. Maar, Vol. I, pp. zog-218 (No. XVII). 5. De Prima Ductus Salivalis Exteriorts Inventione, et Bilstants Experimentis.