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Selected Scientific Works of Hans Christian Orsted

Selected Scientific Works of Hans Christian Orsted

Hans Christian Ørsted
Copyright Date: 1998
Pages: 688
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    Selected Scientific Works of Hans Christian Orsted
    Book Description:

    Hans Christian Ørsted (1777-1851) was one of the leading scientists of the nineteenth century, having played a crucial role in founding electromagnetism. Unfortunately for the English-speaking world, almost all of his research was published in other languages, particularly his native Danish. This book will help to elevate Ørsted to his rightful place in the history of science by finally making his most important scientific works available in English.

    The book includes, for example, Ørsted's account of his revolutionary experiments in electromagnetism. In 1820, he discovered that a compass needle deflects from magnetic north when an electric current is switched on or off in a nearby wire. This showed that electricity and magnetism were related phenomena, a finding that laid the foundation for the theory of electromagnetism and for research that later created such technologies as radio, television, and fiber optics. The unit of magnetic field strength was named the Ørsted in his honor.

    Selections here also show the extraordinary breadth of Ørsted's interests, which range through a long and prolific career from the study of plant alkaloids and the compression of fluids to the nature of light and the "natural science" of beauty. The writings are taken from scientific papers, Ørsted's correspondence, and reports of the Royal Danish Academy of Sciences and Letters. The book will not only draw long overdue attention to Ørsted's own work but will also shed new light on the nature of scientific study in the nineteenth century.

    Originally published in 1998.

    ThePrinceton Legacy Libraryuses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

    eISBN: 978-1-4008-6485-0
    Subjects: History of Science & Technology

Table of Contents

  1. Front Matter
    (pp. i-iv)
  2. Table of Contents
    (pp. v-viii)
    (pp. ix-xiv)
    Karen Jelved and Andrew D. Jackson
    (pp. xv-2)
    Andrew D. Wilson

    Without question, Hans Christian Ørsted’s discovery of electromagnetism ranks among the greatest experimental discoveries in the history of science. It opened a new era not only in the development of physics, leading to the seminal theories and discoveries of Ampère, Faraday, Maxwell, Hertz, Einstein, et al., but also in the technological development of world civilization, where its economic, social, environmental, and military consequences have fundamentally changed our lives. Ørsted’s scientific work and achievements, however, were not restricted to this single discovery. He also conducted pioneering research on the compressibility of gases and fluids, especially water, and invented the necessary instruments...

  5. 1 Response to the Prize Question in Medicine Set by the University of Copenhagen in the Year 1797: On the Origin and Use of Amniotic Fluid (1798)
    (pp. 3-25)

    Hereby I deliver to the judgment of the public and, in particular, to that of my fellow students the prize paper in medicine, with which I was fortunate enough to win the announced academic prize in the last prize competition. I think that my fellow students would prefer to see it printed unchanged, as it was when it was submitted, and I owe them the courtesy to fulfill this presumed wish, but as I owe to Truth the correction of the errors to which my judges have drawn my attention, this has been done in the added rectifying notes, designated...

  6. 2 Letters on Chemistry. First Letter (1798)
    (pp. 26-28)

    During our last conversation I promised to explain to you the systematics of chemistry in letters, both because you like this form best, and also because it is best suited for a clear presentation. I am delighted to fulfill my promise, both for your sake and for that of science, which, as you know, I find so much pleasure in communicating to others. I am obliged to begin with the exposition of several concepts which at first glance do not seem to be of any particular interest, but I hope that their importance in what follows will reconcile you to...

  7. 3 Letters on Chemistry. Second Letter, on Heat (1798)
    (pp. 29-34)

    In my last letter, I showed you that bodies possess two fundamental forces, the expansive force and the cohesive force. I now embark on a subject which seems to be connected with these, that is, the theory of heat. Heat expands all bodies which it can act on and thus seems to be causally related to the expansive force, but the investigations which have hitherto been made have not taught us in what way. The feeling which heat produces is all too familiar to you for a description of it to be of any interest; also we describe most poorly...

  8. 4 Letters on Chemistry. Third Letter (1799)
    (pp. 35-40)

    When you saw in my last letter that bodies bind caloric each time they pass from one state to another less solid one, you probably thought at once that bodies must liberate caloric when, conversely, they pass into a more solid state, and you have not deceived yourself in this. There are very many cases in nature which could be explained by this thesis alone and thereby also serve as proof of its validity. Thus you see that heat is generated even at the transition of water to solidity (to ice). You merely place a thermometer in water which is...

  9. 5 Letters on Chemistry. Fourth Letter (1799)
    (pp. 41-45)

    We now proceed to the contemplation of that remarkable phenomenon in nature whereby the most concentrated and the greatest quantity of heat that we know of is generated; you understand that I can only mean combustion. The explanation of this phenomenon has the most profound effect on the whole of chemical theory; indeed, it serves as the foundation of the entire system which is now accepted in this science, and the older but now rejected system also centred completely on this topic. Therefore it must be very important for us to consider all the circumstances which accompany this phenomenon and,...

  10. 6 Fundamentals of the Metaphysics of Nature, Partly According to a New Plan (1799) PROMPTED BY FOUNDATIONS OF PHYSICS BY THE LORD STEWARD HAUCH
    (pp. 46-78)

    If a body of empirical knowledge is to be able to claim the name of science in the true sense of this word, these experiences must be joined according to certain general and necessary laws which themselves cannot be drawn from experience but must be proved without its help (a priori). If this is not the case with an organized body of experience, it does not at all satisfy the scholar but leaves him standing at a limit which he is not certain is extreme and shows him laws which he dare not assume to be general and necessary because...

  11. 7 Dissertation on the Structure of the Elementary Metaphysics of External Nature (1799) WHICH HANS KRISTIAN ØRSTED, GRADUATE IN PHARMACY, WILL DEFEND ON SEPTEMBER 5 TO OBTAIN THE HIGHEST HONOURS IN PHILOSOPHY
    (pp. 79-100)

    Before I submit these humble pages to the examination of learned men, it might not be inappropriate to point out that they were written within a short time although I had been thinking about the matter in question for quite a while. In fact, I had already obtained the permission to dispute for the highest honours in philosophy when I received the news that I would shortly be leaving this university, but I had not yet finished writing the dissertation, so I was forced to rush. Therefore, benevolent reader, I ask you to be so kind as to forgive me...

  12. 8 Experiments and Observations Concerning Galvanic Electricity (1801)
    (pp. 101-103)

    From the moment when English chemists had observed the gasification which the voltaic apparatus was capable of producing from water and the strange phenomenon that this generation happened in such a way that oxygen gas was generated at one conductor while hydrogen gas appeared at the other, this apparatus, and the galvanic electricity thus produced, became the object of every chemist’s attention. However, when Ritter, by repeating these experiments with certain changes, made it likely² that water was not composite, but that each of the generated gases was a product of water combined with one of the electric substances or...

  13. 9 An Addendum by Dr. Ørsted to His Remarks on Galvanism (1801)
    (pp. 104-105)

    Since my first report I have often repeated the experiment to produce galvanism by dissolving zinc in dilute sulphuric acid. Only simple conductors, consisting of plain iron wire, were used, and the result was always successful. So far I have not tried more than 30 tubes. The battery thus composed seems to me to produce a stronger effect than 30 plates of graphite and zinc. I base this opinion primarily on the intensity of the associated generation of gas from water. The effect on the organs of taste was very pronounced, but there were no or only extremely minor vibrations...

  14. 10 Continued Experiments on Galvanism (1801)
    (pp. 106-106)

    Diluted syrup of violet was brought into contact with a galvanic battery by means of two gold wires, whose points were approximately 2 inches apart. After 5 or 6 minutes the syrup around the negative galvanic needle showed a highly perceptible green colour, around the positive needle, however, a not quite so perceptible red. After some hours both colours were much more perceptible and widespread: yet the red was not nearly so strong as the green, a phenomenon which could be foreseen as the green colour which alkalis give to syrup of violet has far more intensity than the red...

  15. 11 A Review of the Latest Advances in Physics (1803)
    (pp. 107-119)

    At this moment, it is most delightful to take a look at the recent history of physics. The lively eagerness, the courageous contempt for scientific prejudice, and the profound sense of higher things which inspire not all and not even the majority of physicists, but which still emanate from some great investigators with warming rays over all, show us the beginning of a new creation. The tendency towards chaotic formlessness still struggles in vain with the light that begins to spread creatively over all.

    We shall seek to communicate the most important products of this gloriousZeitgeist. Light is the...

  16. 12 Materials for a Chemistry of the Nineteenth Century (1803) FIRST PART
    (pp. 120-165)

    Thechemical systemwhich, a few years ago, after much dispute, hence after much testing as well, was acknowledged almost everywhere in Europe as a collection of completely confirmed facts and as a concatenation of principles based on the most accurate investigations, has already begun to waver again following the discoveries made by means of thevoltaic pile. A courageous and meticulous researcher has already stated this, more cautious investigators are at least in doubt,² and only lethargic indolence still believes that its structure rests unshaken on its old pillars. One important step has already been taken, and we can...

  17. 13 Correspondence (1804)
    (pp. 166-167)
    J. C. Ørsted

    Copenhagen, September 10, 1804.

    My work in physics runs in part parallel to my lectures, and therefore I have only recently returned to the investigations of Winterl’s chemistry. When I was in Berlin, I had already begun a series of experiments on Winterl’s inert or insipid sulphurous acid in the laboratory of Privy Councillor R. Hermbstadt, but my trip prevented me from continuing this series. However, during this work I found a new example to be added to the many older ones which prove how very often our chemical knowledge, considered established, is lacking in reliability. The sulphite of potash...

  18. 14 Galvano-Chemical Observations (1804)
    (pp. 168-169)

    Recently, I have discovered a galvano-chemical phenomenon which has not previously been observed. The reason for this was the following: Several years ago Ritter told us about the discovery that the conductors of an electric pile are covered with sooty shapes when held in the flame of a candle. The sooty shapes on the hydrogen side are vegetal, but the ones on the oxygen side have a different shape. It was to be assumed that each oxidation would be associated with the same formation. I wanted to investigate this. To this end, I put a solution of acetate of lead...

  19. 15 Criticism of the So-Called Eudiometry with Regard to Medicine (1805)
    (pp. 170-179)

    From the moment when it was discovered that atmospheric air was able to sustain life and combustion solely through its oxygen gas, or vital air, people also began to think of ways in which to discover how much of it air contained. Thereby they thought to be able to measure the fitness of air for health and thus gave the name of eudiometry to the art of determining the content of oxygen in air. It was soon discovered that the method which had first been used for this determination was full of errors. Consequently new methods were invented, but they...

  20. 16 A Letter from Dr. Ørsted of Copenhagen to Mr. J. W. Ritter of Jena, Concerning Chladni’s Acoustic Figures in an Electrical Context (1805)
    (pp. 180-180)

    Copenhagen, October 5, 1804.

    I have conducted several experiments on Chladni’s acoustic figures which may offer important insights into the theory of sound. I believed that I would also be able to discover electrical phenomena in the production of the acoustic figures and therefore chosesemen lycopodiito strew on the glass plates instead of sand, in the hope that this dust would adhere to the positively charged places and would easily fall off the negatively charged ones. The first thing I observed during this experiment was that a number of small waves or nodal points developed with each stroke...

  21. 17 A Letter from Mr. Ørsted, Professor of Philosophy in Copenhagen, to Professor Pictet on Acoustic Vibrations (1805)
    (pp. 181-184)
    J. C. Ørsted

    Copenhagen, May 26, 1785


    The impartial interest which you take in all that can further the progress of science has, for a long time, made me desirous of establishing a correspondence with you. I hasten to take the opportunity given to me by a traveller who is going to Geneva and is willing to deliver to you some results of my researches in physics. As the subject of my present letter, I have chosen the experiments which I have made, and repeated many times, on the effects produced in the interior of solid bodies during the propagation of motion....

  22. 18 On the Harmony Between Electrical Figures and Organic Forms (1805)
    (pp. 185-191)

    The remarkable similarity which the figures that electricity produces on dusted surfaces have to the forms of organic beings has often attracted the attention of students of nature, but they have only been able to suggest the full connection between them imperfectly because some of the most recent electro-chemical discoveries are needed to present this connection in a clearer light.

    The primary form of positive electricity is the radiating point, of the negative, on the other hand, the circle so that one seems to form the internal, the other the external, one the point which radiates from its centre in...

  23. 19 New Investigations into the Question: What Is Chemistry? (1805)
    (pp. 192-199)

    After so many talented men, through several centuries, have endeavoured so eagerly to systematize chemistry, it might, at first glance, appear ridiculous to wish once more to pose the question: What is chemistry? It seems unreasonable to assume that so many clever men should not only have occupied themselves with chemical investigations but also sought to fit all chemical knowledge into a system, without first having asked and, through accurate measurement of the scope of the science, answered this question. I know all too well that many who hate all radical changes in science and, like inanimate objects, prefer to...

  24. 20 An Attempt towards a New Theory of Spontaneous Combustion (1805)
    (pp. 200-209)

    Experience teaches us that there are bodies which have the property that, under certain circumstances, they are able to burst into flames without the application of any external fire or heat. These bodies have been calledspontaneously combustible. The observations of chemists have familiarized us with several of these, and sad experience has made us aware of others. The bodies and their combinations which have proved to be spontaneously combustible have been diligently recorded. Both the intrinsic interest of the phenomenon and the importance of the matter in practical life urged this. However, in spite of all the diligence applied...

  25. 21 On the Manner in Which Electricity Is Transmitted (A Fragment) (1806)
    (pp. 210-214)

    As far as I know, no-one has yet attempted to penetrate into the internal mechanism of the transmission of electricity. It might also be very difficult to reveal the full secret of this process, but some interesting conclusions about this can certainly be drawn from the nature of things and from several well-known facts.

    The first effect of an electrified object on one which is not electrified is, as is well known, to create an electric polarity in it. If we designate the charged object byA, andBCrepresents a conducting cylinder, thenBreceives the electricity opposite to...

  26. 22 Correspondence (1806)
    (pp. 215-217)

    Copenhagen, March 4, 1806.

    Volta’s assertion that the storage battery merely resulted from the layers of alkali and acid produced during charging is not consistent with the experiments even if it were true that two charged metal wires lose their strength by being washed in water, which I dare to doubt. However, if it were true, I would say that this must originate in some other property of the electric charge, for if several tubes of water joined by metallic wires are connected with a galvanic pile but are separated from it again after a few minutes, the outermost wires...

  27. 23 Experiments Prompted by Some Passages in Winterl’s Writings (1806)
    (pp. 218-226)

    1. So far nothing more than assertions, hypotheses, and among experiments only those whose superficiality immediately leaps to the eye have been set up against Winterl’s writings. Nor have the works of this famous researcher given rise to many new experiments which would be able to confirm his theory, extend, or further determine its individual theorems.² I had early imposed on myself the obligation to contribute to this goal since I had recommended the investigation of Winterl’s work with so much warmth, but at the beginning my scientific journeys hindered me, and after that I was occupied with other experimental work...

  28. 24 The Series of Acids and Bases (1806)
    (pp. 227-242)

    The acids and their opposite, the bases, have not yet been organized as they deserve. The reason for this lies entirely in the previous treatment of chemistry. All attention was directed only towards the components of bodies. No independent comparison and organization of the substances were attempted, or only in an extremely superficial manner. In this way, however, only extremely limited knowledge of nature could be achieved, and furthermore, it must often lead to error, for our knowledge of the components of bodies is still very incomplete. First, there are a significant number of bodies whose components we do not...

  29. 25 Reflections on the History of Chemistry, A Lecture (1807)
    (pp. 243-260)

    It is an old, often repeated complaint that there is no agreement in the realm of science. Precisely where one expected an eternal peace, a unanimous effort towards one goal, there a continuous internal war reigns in ever changing upheavals. Who does not know how much occasion this discord has given the timid for distrust, the scoffer for laughter, and the enemy of science for declamations on the uncertainty of human knowledge.

    What I said in the last lecture regarding the fall of antiphlogistic chemistry must occasion the same complaint. Once again we had to reject a theory which was...

  30. 26 On Acoustic Figures (1807)
    (pp. 261-262)

    I have almost completed an article for your journal, in which I have further elaborated on my discoveries on acoustic figures, which I have already mentioned in Voigt’sMagazin, Vol. 9, p. 31² and in yourN. allg. Journ. d. Chem., Vol. 6. Through the most precise measurements I have now convinced myself that in all the cases where Chladni assumes triangular oscillating areas and states that the dust lines intersect, nothing but hyperbolas are to be found. Hence, the figure which Chladni depicts as two crossing diagonals of a square ⊠ actually consists of two complete hyperbolas with crossing...

  31. 27 Ørsted on Simon’s (Volta’s) New Law for Electrical Atmospheric Effects (1808)
    (pp. 263-263)

    Copenhagen, Sept. 3, 1808.

    The printing of my textbook on physics, which was burned during the siege, has now been resumed and is progressing swiftly.

    A year ago, I also made Simon’s discovery that electricity spreads according to the inverse ratio of the distances, and not the squares of the same, but I made it in a different way. Before long, I shall publish a paper about this in which I shall not concern myself so much with this discovery but rather with some conclusions which can be drawn from it. The most important of these is that electricity which...

  32. 28 Experiments on Acoustic Figures (1810)
    (pp. 264-281)

    The figures which appear on dusted surfaces of elastic bodies when tones are produced in them have already shed much light on the theory of sound, but in addition they present so many hitherto inexplicable phenomena, so many traces of undiscovered secrets that the student of nature cannot possibly contemplate them with equanimity. Through a series of many hundred experiments I have endeavoured to get somewhat closer to the inner mechanism of these remarkable phenomena, and I now believe that I have brought my investigations to the point where I dare submit them to the scrutiny of other students of...

  33. 29 First Introduction to General Physics (1811) A PROSPECTUS OF LECTURES ON THIS SCIENCE
    (pp. 282-309)

    The present treatise is a more extensive version of the introduction to the textbook which I published two years ago. Gradually I intend to treat more of its parts in the same way and thus provide my readers with a collection of pamphlets which in time might constitute a larger whole. Its more immediate purpose, however, is to serve as the basis for a small series ofprefatory lectureswith which I shall introduce my lectures on the various parts of general physics. These introductory lectures will start on Monday, November 18, and be given every Monday, Wednesday, Thursday, and...

  34. 30 View of the Chemical Laws of Nature Obtained Through Recent Discoveries (1812)
    (pp. 310-392)

    In the investigations of chemical effects so far, we have always stopped at the so-called affinities or attractions as the final limit which we could reach. This could not possibly mean that the ultimate reason for all chemical effects had been determined, but the unknown cause had to be given a name, and at the beginning the more figurative term,affinity, was chosen, and later the more characteristic term,attraction. The evolution of science, however, almost always caused attention to be directed towards the particular nature of each affinity. What has been accomplished in this respect in chemistry, thanks to...

  35. 31 On the Law of Electrical Attraction (1814)
    (pp. 393-393)

    Copenhagen, Nov. 22, 1814.

    I have finished a very significant series of experiments on the decrease of electric forces with increasing distances, from which it turned out that the forces are in an inverse relation neither to the distances nor to the squares of the distances, but that the decrease can only be expressed by a series. Immediately after the New Year, you will receive a paper about this in which some not insignificant conclusions will also be drawn from this law....

  36. 32 Proposal for New Danish Terms in Chemistry (1814) The Law for the Weakening of Electrical Effects with Distance (1815)
    (pp. 394-396)

    Professor Ørsted, Knight of the Order of Dannebrog, has submitted to the Society a proposal for new Danish terms in chemistry. He remarks that, since the introduction of antiphlogistic chemistry, the chemical terminology in Danish, German, Swedish, and Dutch is merely a translation from the French. In these translations the mistake has been committed of designating the first, simplest elements we know by means of derived or compound words, from which it was then, naturally, impossible to form easy and convenient words for compound objects. As a consequence of this, native terminology had to be mixed with foreign words, which...

  37. 33 Theory of Light (1816)
    (pp. 397-399)

    Professor Ørsted, Knight of the Order of Dannebrog, has submitted his theory of light to the Society. As is well known, only two theories of the nature of light have received any considerable approbation. One of these, which bears the name of Newton, assumes that light consists of a fine substance which streams from the luminous body in all directions with extraordinary speed; the other, which was elaborated by Euler with much art, assumes that light is a motion in an all-pervasive ether. Although physicists now more or less agree on their preference for Newton’s theory, they readily admit that...

  38. 34 On Galvanic Trough Apparatuses and Spark Discharge in Mercury Vapour (1816)
    (pp. 400-401)

    Even though galvanic trough apparatuses have many important advantages, especially when the object is to obtain very great effects, most of these devices have not quite satisfied the wishes of physicists. If the troughs are made of wood, they will soon be saturated by the acids in spite of the application of all kinds of varnish, and the connection thus created weakens the effect considerably. If instead one uses partitioned china troughs, in which the zinc and copper plates are suspended, a much greater and more certain effect is obtained, but this kind of trough will be very expensive when...

  39. 35 Observations Regarding Contact Electricity (1817)
    (pp. 402-406)

    My treatise on the law of electrical repulsions was completed 2 years ago in the form in which it was read to the Society of Sciences. However, it was my wish to repeat these experiments with another apparatus, but this has not been constructed by the artisan quite in accordance with my wishes. This circumstance has caused a delay. This summer, I certainly hope to make this treatise more worthy of the attention of physicists with this addition.

    During the last year I have occupied myself a great deal with galvanic apparatuses and their arrangement and have, in the company...

  40. 36 On the Compression of Water (1817)
    (pp. 407-407)

    Copenhagen, April 28, 1818

    Lately I have been preoccupied with the compression of water. The book by Zimmermann on this topic is filled with the strangest calculational errors. Once these errors are corrected, there is far more harmony among the results of the experiments than was previously believed. I have also conducted entirely new experiments on this topic, which show that the compression of water is proportional to the compressing forces, as Canton claimed based on very limited experiments, but which Zimmermann’s experiments contradicted, in the form in which these results have been presented so far. I have found that...

  41. 37 On the Way in Which a Textbook in Physics Ought to Be Written (1817); Investigations on the Compressibility of Water (1818)
    (pp. 408-410)

    Professor Ørsted, Knight of the Order of Dannebrog, has submitted to the Society two papers, one of which was the first of a series of papers on the way in which textbooks in physics ought to be written; the other contained an investigation of the compressibility of water.

    It is well known that many textbooks in physics have been published in various European countries in recent years. Although there are not a few differences of opinion about the causes of things, even in books from the same period, the differences in treatment seem far greater. It has not even been...

  42. 38 On Piperine, a New Plant Alkaloid (1820)
    (pp. 411-412)

    Copenhagen, February 15, 1820.

    The discoveries of new alkalis in plants have led me back to an old piece of work on pepper which I began several years ago.² By resuming this investigation, I easily discovered a new alkaline substance which we shall merely callpiperinewithout searching for a more suitable name derived from its nature because our knowledge of the entire class of substances to which this belongs is still so new and incomplete. Piperine is obtained by extracting the resinous and oily substances from pepper by means of alcohol; piperine is also contained in the solution formed...

  43. 39 Experiments on the Effect of the Electric Conflict on the Magnetic Needle (July 21, 1820)
    (pp. 413-416)
    Hans Christian Ørsted

    The first experiments on the subject which I shall address here were made during the lectures which I gave last² winter on electricity, galvanism, and magnetism. It seemed demonstrated by these experiments that the magnetic needle can be moved from its position by means of a galvanic apparatus, but by a closed galvanic circuit, not an open one, as several very celebrated physicists tried in vain some years ago. However, as these experiments were made with a less effective apparatus, and as the resulting phenomena therefore did not seem sufficiently clear, considering the importance of the subject, I joined with...

  44. 39a Experiments on the Effect of a Current of Electricity on the Magnetic Needle (1820)
    (pp. 417-420)

    The first experiments respecting the subject which I mean at present to explain, were made by me last winter, while lecturing on electricity, galvanism, and magnetism, in the University. It seemed demonstrated by these experiments that the magnetic needle was moved from its position by the galvanic apparatus, but that the galvanic circle must be complete, and not open, which last method was tried in vain some years ago by very celebrated philosophers. But as these experiments were made with a feeble apparatus, and were not, therefore, sufficiently conclusive, considering the importance of the subject, I associated myself with my...

  45. 40 New Electro-Magnetic Experiments (1820)
    (pp. 421-424)

    Since the publication of my first experiments on the magnetic action of the galvanic apparatus,² I have multiplied my researches on that subject as much as my other duties permitted.

    The electro-magnetic effects do not seem to depend on the intensity of the electricity, but solely on its quantity. If a strong electric battery is discharged through a metallic wire above a magnetic needle, the latter acquires no motion. An uninterrupted series of electric sparks acts on the needle through ordinary electric attraction and repulsion but produces no genuine magneto-electric effect. A galvanic pile, composed of one hundred two □–...

  46. 41 Note on the Discovery of Electromagnetism (1821)
    (pp. 425-429)

    Over the years, Professor Ørsted, Knight of the Order of Dannebrog, has submitted to the Society a series of investigations of magnetism, whereby it is shown that the magnetic effects are produced by the same forces as the electric. For a long time many students of nature have suspected this connection, but neither did they have conclusive evidence of it, nor did they guess the relationship between electricity and magnetism which experiments have now shown us. A long time ago the author himself adopted a system according to which all internal effects in bodies, such as electricity, heat, light, as...

  47. 42 Observations on Electro-magnetism (1821)
    (pp. 430-445)

    When I began to examine into the nature of electricity, I conceived the idea that the propagation of electricity consisted in a continual destruction and renewal of equilibrium, and thus possessed great activity which could only be explained by considering it as a uniform current.² I then regarded the transmission of electricity as an electrical conflict, and my researches into the nature of the heat produced by the electrical discharge, particularly led to the conclusion, that the two opposite electrical forces, which pervade a body heated by their effect, are so blended as to escape all observation, without however, having...

  48. 43 Correspondence (1821)
    (pp. 446-449)

    In a treatise on electro-magnetism, Vol. 2, No. 2,² a printing error has slipped in which is insignificant in itself but might still bother the reader, viz., everywhere it reads +Fand −Finstead of +Eand −E. I wish to point out that printing error since, in my future communications, I always intend to designate the two electrical activities by the usual +Eand −Ewhile using the corresponding Greek letter ε for the designation of electro-magnetism, the latter having been correctly printed. An error has also occurred in the copperplate in Fig. 5, whereRSThas been displaced....

  49. 44 An Experiment on Zamboni’s Double Galvanic Circuit (1821)
    (pp. 450-451)

    I have recently conducted a series of experiments on Zamboni’s double galvanic circuit. Even though my experiments are not as complete in all regards as I had intended, the results already obtained may nevertheless be of some interest and also serve as models for the application of electro-magnetism in other investigations. The principal experiment which I have conducted is the following:

    Two zinc sheets of different size, that is, one narrow, the other wide, are immersed in a diluted acid and each connected to one end of the wire of Schweigger’s galvano-magnetic condenser. The magnetic needle of the condenser will...

  50. 45 A Method to Facilitate the Generation of Steam (1822)
    (pp. 452-452)

    In Gehlen’sJournal für Chemie und Physik, Vol. 1 (Berlin, 1806), pp. 277–89,² I announced some experiments which showed that gas generation, which was supposed to take place in a liquid according to its chemical constituents, does not take place unless it is facilitated by contact with a solid body. Naturally, the same procedure can be applied to the generation of steam. If a metal wire is suspended in the middle of a boiling liquid, it will be seen that bubbles of vapour adhere to this as well as to the bottom of the vessel in which the boiling...

  51. 46 The Ørsted Experiment on the Compression of Water (1822)
    (pp. 453-456)

    Several years ago, Prof. Ørsted submitted some experiments on the compression of water to the Royal Society of Copenhagen, and on this occasion he showed that this might be produced by a much smaller force than is generally assumed, provided the instrument was constructed according to the well-known principle that a pressure acting on a small part of the surface of an enclosed liquid has the same effect as an equally great force acting on each similar part of the whole surface. For the compression of water he made use of a wide brass cylinder, on which was screwed a...

  52. 47 On the Compressibility of Water (1823)
    (pp. 457-461)

    Although Canton’s experiments established the compressibility of water more than fifty years ago, people have not generally had the confidence in them which they deserve because the methods which this English philosopher used permitted changes in temperature to exert a considerable influence on the results. The rare ingenuity of this scientist was needed to avoid this influence, especially at a time when instruments did not yet have the perfection which they have acquired in our time. Therefore, a great many experiments on the same subject were published after Canton, but they were quite inferior to his, both because of the...

  53. 48 New Experiments by Dr. Seebeck on Electromagnetic Effects (1823)
    (pp. 462-463)

    Dr. Seeback, a member of the Academy of Berlin, has discovered that an electric circuit can be produced in metals without the interposition of any liquid. The current is established in this circuit by disturbing the equilibrium of the temperature. The apparatus for demonstrating this effect is very simple. It consists of two arcs of different metals, for instance, copper and bismuth, soldered together at both ends so that they form a circle. It is not even necessary that the metal pieces have the shape of an arc, or that their combination has that of a circle; it suffices that...

  54. 49 An Electromagnetic Experiment (1823)
    (pp. 464-465)

    Immediately after the discovery of electromagnetic phenomena, several distinguished physicists thought that they could explain them by assuming two magnetic axes in each transverse section of the conductor. In reality, it seems that the authors of this hypothesis abandoned it as soon as multiple experiments showed its inadequacy. Later, however, there have been other physicists who have tried to restore it to favour, which is why I thought that an experiment designed to show directly that every point on the circumference of the electric current has an equal action on the magnetic needle would not be entirely superfluous even now....

  55. 50 On M. Schweigger’s Electromagnetic Multiplier, with an Account of Some Experiments made with it (1823)
    (pp. 466-469)

    Immediately after the discovery of electromagnetism, Prof. Schweigger, of Halle, invented an extremely useful instrument for the purpose of discovering very weak electrical currents by means of the magnetic needle. The effect of this multiplier is founded upon the equal action which every part of a conducting wire when it transmits a current exerts upon the magnetic needle. When a part of this wire is curved as inabc, fig. 1, so that the two branchesabandbcare in a vertical plane, and a magnetic needledeis properly suspended in the same plane, it will be readily...

  56. 51 On Some New Thermoelectric Experiments Performed by Baron Fourier and M. Ørsted (1823)
    (pp. 470-477)

    I have had the honour of demonstrating to this illustrious assembly the remarkable experiments by which M. Seebeck has proved that an electric current may be produced in a circuit formed of solid conductors only by disturbing the equilibrium of the temperature. (SeeAnnates, Vol. 22, p. 119.²) We are therefore in possession of a new class of electric circuits, which may be calledthermoelectric circuits, thus distinguishing them from galvanic circuits, which from now on may conveniently be calledhydroelectric. On this subject, a question arises which is of interest to electromagnetism and also to the theory of the...

  57. 52 On an Apparent Paradoxical Galvanic Experiment (1824)
    (pp. 478-480)

    In a Memoir, published some months ago, by M. Von Moll,² at Utrecht,³ this philosopher (already known from various experimental researches) describes an experiment, which, at first sight, appears to indicate a new class of galvanic phenomena.

    I have submitted this experiment to an attentive examination. Fig. 1 is the apparatus of M. Von Moll.ABCDis a perpendicular section of a plate of zinc, bent in such a way that its extremities touch, and form a closed circuit.NSis a magnetic needle, properly suspended. The partAof the circuit is plunged in acidulated water.

    If any point...

  58. 53 Experiments Proving That Mariotte’s Law Is Applicable to All Kinds of Gases; and at All Degrees of Pressure under Which the Gases Retain Their Aëriform State (1825)
    (pp. 481-491)

    The so-called law of Mariotte,² according to which the volumes occupied by a certain quantity of gas or air are found to be in an inverse ratio to the degrees of pressure which they experience, has hitherto been demonstrated by precise experiments for very small degrees of pressure only. Several men of science of the first rank have assumed this law to be in exact conformity with nature for every degree of pressure; others, among them Jacob Bernoulli and Euler, entertained the opinion that the volumes decrease at a smaller rate than that at which the pressure increases; and if,...

  59. 54 Preliminary Note on the Production of Aluminium, Aluminium Chloride, and Silicon Chloride (1825)
    (pp. 492-492)

    I shall soon bring you news about some new experiments whereby I have succeeded in producingaluminium chlorideand, from that,aluminium. The aluminium chloride is obtained as a volatile substance when dry chlorine is spread over a glowing mixture of alumina and coal. Silicon chloride is obtained in the same way, but here the volatile substance must be greatly cooled.—More of this shortly....

  60. 55 Contribution to the Determination of the Law of the Compression of Bodies (1826)
    (pp. 493-517)

    The fact that a body can be forced by pressure to occupy a smaller volume, and that its parts can return to their previous position when the pressure has ceased, is a natural effect whose singularity is forgotten because of its daily occurrence, but in which the essence of corporality manifests itself most directly. It is not my intention here to add to the many researches that have been ventured upon regarding the cause or the internal nature of this property, but I shall endeavour to make a contribution to the knowledge of its mode of action. It appears that...

  61. 56 [Improvements of the Compression Apparatus 1826. Measurement of the Compressibility of Mercury] (1827)
    (pp. 518-525)

    At the end of the “Contribution to the Determination of the Law of the Compression of Bodies,” which is to be found in the last volume ofDet Kongelige Videnskabernes Selskabs Skrifter,² and in which I have presented the finest of the experiments I have conducted on this subject for several years, I called attention to the many points which remained to be elucidated. Later, at the meeting on May 12th of last year, I had the honour of further developing the nature of these needs, which I had only briefly touched on the last time. With gratitude I acknowledge...

  62. 57 On the Relative Compressibilities of different Fluids at High Temperatures (1827)
    (pp. 526-527)

    Copenhagen, December 30th 1826

    Having in the course of last summer performed a very great number of experiments on the compressibility of different fluids, and particularly on the compressibility of water at high pressures, I am now about to calculate the corrections which must be introduced for the variations of atmospherical pressure, temperature, &c. As soon as the paper is finished I will send you a translation of it. The following results, however, will not be much affected by these corrections.

    1. As far as the strength of my apparatus has permitted me to push the compression of water, (viz. seventy...

  63. 58 An Electromagnetic Method for the Assay of Silver and Other Metals Invented by M. Ørsted (1828)
    (pp. 528-534)

    The preference which has always been accorded to certain metals, regarded as more precious than others, depends in particular on the degree of immutability which they exhibit under the influence of air, of water, of fire, or of other chemical forces of nature, but the resistance to these agents is related to the ability of these metals to combine with oxygen. The less the metal attracts this gas, the better it generally preserves its metallic nature under the influence of foreign bodies. It could also be said that the less combustible a metal is, the more it deserves the designation...

  64. 59 Observations Concerning the Compressibility of Fluids (1828)
    (pp. 535-536)

    Messrs Colladon and Sturm dismiss the procedure earlier suggested by myself to block the water in the narrow tube of the compression bottle with mercury. I agree with them in this, and more than a year ago I showed the Society and many enthusiasts of physics an apparatus in which the narrow tube of the bottle is blocked by air. In addition, I have made another improvement of the compression bottle, which does not yet seem to have been attempted by anyone else. The narrow tube is not fused to the bottle but ground in its neck. This arrangement, which...

  65. 60 On the Compression of Water in Vessels of Varying Compressibility (1828)
    (pp. 537-538)

    Among the problems which present themselves in the investigations of the compressibility of liquids, the following has also been mentioned on the occasion of a prize question posed by the Paris Academy of Sciences: What influence would the compressibility of the walls of the vessel containing the object of the experiment have on the results? This influence can be considered from two different points of view. Some physicists have believed that the walls of the vessel are compressed in all directions so that the vessel loses in capacity due to the pressure it experiences from the compressed liquid. Others, on...

  66. 61 A New Electromagnetic Experiment Disproving Ampère’s Theory (1830); Remarks on the Relation Between Sound, Light, Heat, and Electricity (1830)
    (pp. 539-541)

    Councillor of State² and Professor Ørsted has informed the Society of a new electromagnetic experiment which he believes to be inconsistent with Ampère’s theory.³ It is a familiar experience in the history of science that opposing theories about a natural phenomenon are able to persist for a long time even though there may be arguments which should decide the issue. In such a case an attempt must be made to devise an experiment which cannot possibly be explained in two ways. If one stopped at a crossroads where one did not know which direction to take, such anexperimentum crucis,...

  67. 62 Thermo-Electricity (1830)
    (pp. 542-580)

    Thermo-electricity is a term introduced a few years ago into natural philosophy, to signify the electrical current, excited in a circuit of conductors, when the equilibrium of its heat is disturbed in such a manner as to cause therein a circulation of caloric.

    Thermo-electricity being a particular branch ofElectromagnetism, which has been discovered since the publication of the volume of this work in which it ought to have been treated, it will be necessary to comprehend the whole doctrine of electromagnetism in the present article.

    In the earliest period of the history of magnetism and electricity, the minds of...

  68. 63 An Explanation of Faraday’s Magneto-Electric Discovery (1832)
    (pp. 581-582)

    Councillor of State Ørsted, Knight of the Order of Dannebrog, has informed the Society of his explanation of Faraday’s magneto-electric discovery. From the time when electromagnetism was discovered, it became a natural question whether it would not be equally possible to produce electricity by means of magnetism as magnetism by means of electricity. In spite of many efforts, however, no one had succeeded in doing this until the end of last year, when the English natural philosopher Faraday invented the proper means to do so, which is the following. In the proximity of a good conductor, north and south magnetism...

  69. 64 Results of New Experiments on the Compressibility of Water (1834)
    (pp. 583-585)

    Ørsted has continued his experiments on the compressibility of water. Although the agreement of his experiments on this subject with the ones by foreign physicists leaves essentially nothing to be desired, there remain several points in this investigation which merit continued work. One of these is that water is less compressed, the warmer it is. We have some experiments on this subject by Canton from the middle of the last century, and these were confirmed by Ørsted’s earlier experiences; it is only the connection between this peculiarity of water and other laws of nature which requires further investigation. This has...

  70. 65 On the Compressibility of Water (1834)
    (pp. 586-592)

    Were I not withheld by official duties, I should certainly not omit so excellent an opportunity of renewing the very interesting and useful acquaintance I made during my last visit to England and Scotland, and of forming new ones with those distinguished scientific characters that I was not fortunate enough to meet with at that time, or such as have risen to eminence of late years. But though I must now forgo this advantage, I will not let this opportunity pass without giving the illustrious assembly some mark of my high esteem, and of my desire to keep up the...

  71. 66 New Experiments on the Effect of the Electrical Circuit (1835)
    (pp. 593-594)

    Councillor of State Ørsted, Knight Commander of the Order of Dannebrog, has presented to the Society some new experiments on the effect of the electrical circuit. As is well-known, Faraday, in his famous series of papers on electricity and magnetism, has reported a number of experiments in which the magnetic effects of the electrical circuit were very closely related to the oxidations which occurred in it. It cannot be denied that this relation really exists in the experiments which the English philosopher has reported, but there are other experiments which have the completely opposite result. Berzelius had demonstrated earlier that...

  72. 67 On a New Electrometer (1841)
    (pp. 595-596)

    This instrument, which was demonstrated to the Royal Society of Sciences in Copenhagen, is shown in fig. 1 at half size.

    aais a thin, annealed brass wire which acts as the indicator,bbba bow made of very thin iron wire which must have the slightest magnetism,ccccccis a brass tube which ends in a bow,eea pin around which one end of a cocoon silk thread is wound; this thread supports the indicator.

    ddddis a glass tube in which the brass tube with the bowed end has been fastened by means of rubber cement. The...

  73. 68 A New Device for the Measurement of Capillarity (1841)
    (pp. 597-598)

    The experimental investigation of the capillary effect has so far been restricted within very narrow limits since tubes or plates of glass had to be used almost exclusively, and yet it would be very important to examine these effects in opaque objects, viz., metals, as well. An apparatus, which is depicted in fig. 1 at ⅛ of its actual size, was constructed in order to remove these restrictions.

    aaaa, bbbb, ccccare glass tubes which are connected with each other. The upper end ofaaaacarries a copper ring which becomes thicker at the top, and its broad rim is...

  74. 69 An Investigation of Light with Regard to the Physics of Beauty (1842)
    (pp. 599-600)

    Professor² Ørsted delivered the first part of a lecture on an investigation of light with regard to the physics of beauty. He first drew attention to the pleasure in light, of which we become especially conscious at the transition from a long darkness to light, but which we also enjoy, although with less pronounced awareness, under many lighting conditions in nature and in art. In order to demonstrate the connection between this feeling and the essence of things, he drew attention to the fundamental laws of light. No matter how much people may disagree about the nature of light, they...

  75. 70 Continued Reflections on Light with Regard to the Physics of Beauty (1843)
    (pp. 601-602)

    Professor Ørsted continued his reflections on light with regard to the physics of beauty. The object of this continuation was the conditions under which certain figures are produced according to the natural laws of light. Among these is the rainbow. On this occasion, it was not his intention to repeat the well-known theory of the rainbow; it was sufficient to regard this as a settled issue. The shape of the rainbow is a necessary consequence of the mathematical laws of nature. In the same act of nature which forms this arc, the coloured rays contained in white light are also...

  76. 71 Development of the Theory of Lustre (1843)
    (pp. 603-606)

    Professor Ørsted informed the Society of a development in the theory of lustre.

    He began with the statement that what he had to communicate was not essentially new but only a compilation of well-known truths, but as this had not been made elsewhere, as far as he had been able to ascertain, he did not consider it inappropriate to offer the insights which he has acquired.

    In order better to attract attention to what matters here, he started with the apparent contradiction in the combination of blackness and lustre since as little light as possible is reflected according to the...

  77. 72 An Account of Experiments on the Heat Generated by the Compression of Water (1845)
    (pp. 607-609)

    Professor H. C. Ørsted gave a preliminary report of a series of experiments on the heat generated by the compression of water. In 1833 he had informed the Society that, on the basis of his experiments on the compression of water at different temperatures, he had to conclude that approximately1/40°C was generated in the water for each atmosphere of pressure applied. As this depended only on conclusions from experiments which, it is true, did not easily permit another interpretation but still did not prove the issue through direct measurement of the heat generated, he decided to make experiments on...

  78. 73 Letter, on the Deviation of Falling Bodies from the Perpendicular, to Sir John Herschel, Bart. (1847)
    (pp. 610-612)

    The first experiments of merit upon this subject were made last century, I think in 1793, by Professor Guglielmini. He found in a great church an opportunity to make bodies fall from a height of 231 feet. As the earth rotates from west to east, each point in or upon her describes an arc proportional to its distance from the axis, and therefore the falling body has from the beginning of the fall a greater tendency towards east than the point of the surface which is perpendicularly below it; thus it must strike a point lying somewhat easterly from the...

  79. 74 On the Changes which Mercury sometimes suffers in Glass Vessels hermetically Sealed (1847)
    (pp. 613-613)

    It has been frequently noticed that mercury inclosed in glass tubes, even when those tubes were hermetically sealed, undergoes a remarkable change. It first becomes covered by a thin film of a yellow colour, which adheres to the glass, and becomes eventually nearly black. This has been attributed to oxidation, but the oxidation which would arise from the exceedingly small quantity of atmospheric air which could be contained within the bulbs exhibited by Professor Ørsted was too small to account for the formation of such a quantity of dark and yellow powder as many of them exhibited. Professor Ørsted referred...

  80. 75 On Faraday’s Diamagnetic Experiments (1847)
    (pp. 614-615)

    Professor Ørsted demonstrated the highly extraordinary experiments whereby Faraday has discovered the effect which he calls diamagnetism and the change which a magnetic field can produce in certain transparent bodies, according to which they are made to rotate the plane of polarization of transmitted, previously polarized light. It is now well known that Faraday uses the termdiamagneticto describe those bodies which are repelled by both magnetic poles, whereas the ones which we callmagneticare attracted by both if they have not previously been given a fixed polarization. These two different classes of bodies are also given characteristic...

  81. 76 Experiments on the Carrying Capacity of the Large Electromagnet of the Polytechnic School (1847)
    (pp. 616-618)

    At the meeting of the Society on April 23, Professor Ørsted had demonstrated the large electromagnet of the Polytechnic School, by means of which he had performed Faraday’s famous experiments on diamagnetism and on the change which many bodies show with regard to their ability to polarize light. At this meeting he reported some new experiments on the carrying capacity of this electromagnet. The yoke, which is fastened to a base on wheels, was duly secured to the floor so that the forces used to attempt to tear the armature away could not lift it. The first experiments on this...

  82. 77 Abstract of a Series of Experiments on Diamagnetism (1848)
    (pp. 619-625)

    At the meeting of the Royal Society of Science in Copenhagen on June 30,² I presented the results of researches which I had made on diamagnetism, and I gave a report of the same in the transactions of the Society. During the recess of this society, I have continued my researches and obtained several new results. As the memoir which describes these will not appear for several months, I have decided to give an abstract of my results which can be communicated to my foreign friends.

    My researches relate to the celebrated diamagnetic discoveries of M. Faraday and to the...

  83. 78 Investigations on Diamagnetism (1848)
    (pp. 626-631)

    Professor Ørsted gave a report of his investigations on diamagnetism and demonstrated the relevant principal experiments.

    As is well known, diamagnetism was discovered by Faraday. During experiments with his large electromagnet, this famous physicist chanced upon a fact, several examples of which had admittedly been known before, but which his investigations have given a new and much broader significance. In 1778 Anton Brügmanns² had discovered that bismuth was repelled by both poles of a magnet, and Becquerel the Elder had rediscovered the same effect in 1827 and added that antimony also shows it. However, Faraday now discovered, by using his...

  84. 79 Further Investigations on Diamagnetism and Their Results (1849)
    (pp. 632-638)

    At the meetings of January 5th and 19th, Professor H. C. Ørsted, who, at the meeting of June 30th, had informed the Society of the investigations on diamagnetism which he had made up to that time but had since continued, now reported the results which he had later obtained. As his continued work had taken place during a period of time when the Society did not hold meetings, he had had a brief notice² about it printed in French for the benefit of scientists in foreign countries. However, it is not a Danish translation of this notice that he ventured...

    (pp. 639-642)
    (pp. 643-647)