A selection of some recent arrivals November 2019 Rare and important books & manuscripts in science and medicine, by Christian Westergaard. Flæsketorvet 68 – 1711 København V – Denmark Cell: (+45)27628014 www.sophiararebooks.com AMPÈRE, André-Marie. THE FOUNDATION OF ELECTRO- DYNAMICS, INSCRIBED BY AMPÈRE AMPÈRE, Andre-Marie. Mémoires sur l’action mutuelle de deux courans électri- ques, sur celle qui existe entre un courant électrique et un aimant ou le globe terres- tre, et celle de deux aimans l’un sur l’autre. [Paris: Feugeray, 1821]. $22,500 8vo (219 x 133mm), pp. [3], 4-112 with five folding engraved plates (a few faint scattered spots). Original pink wrappers, uncut (lacking backstrip, one cord partly broken with a few leaves just holding, slightly darkened, chip to corner of upper cov- er); modern cloth box. An untouched copy in its original state. First edition, probable first issue, extremely rare and inscribed by Ampère, of this continually evolving collection of important memoirs on electrodynamics by Ampère and others. “Ampère had originally intended the collection to contain all the articles published on his theory of electrodynamics since 1820, but as he pre- pared copy new articles on the subject continued to appear, so that the fascicles, which apparently began publication in 1821, were in a constant state of revision, with at least five versions of the collection appearing between 1821 and 1823 un- der different titles” (Norman). The collection begins with ‘Mémoires sur l’action mutuelle de deux courans électriques’, Ampère’s “first great memoir on electrody- namics” (DSB), representing his first response to the demonstration on 21 April 1820 by the Danish physicist Hans Christian Oersted (1777-1851) that electric currents create magnetic fields; this had been reported by François Arago (1786- 1853) to an astonished Académie des Sciences on 4 September. In this article he AMPÈRE, André-Marie. “demonstrated for the first time that two parallel conductors, carrying currents The collection opens with the ‘Premier Mémoire’ [1] (numbering as in the list of traveling in the same direction, attract each other; conversely, if the currents are contents, below), first published in Arago’s Annales de Chimie et de Physique at traveling in opposite directions, they repel each other” (Sparrow, Milestones, p. the end of 1820 (Series 2, Tome 15, pp. 59-76 in the October issue & 170-218 in 33). This first paper is mostly phenomenological, but it is followed here by the im- November, read 18 & 25 September). “There is some confusion over the precise portant and much more mathematical sequel, ‘Additions au mémoire précédent – nature of Ampère’s first discovery. In the published memoir, “Mémoire sur 1’ac- note sur les expériences électro-magnétiques de MM. Oersted, Ampère, Arago et tion mutuelle de deux courants électriques,” he leaped immediately from the ex- Biot,’ in which Ampère gave the first quantitative expression for the force between istence of electromagnetism to the idea that currents traveling in circles through current carrying conductors. Ampère attempted to explain his observations by helices would act like magnets. This may have been suggested to him by con- postulating a new theory of magnetism – according to him, magnetic forces were sideration of terrestrial magnetism, in which circular currents seemed obvious. the result of the motion of two electric fluids; permanent magnets contained Ampère immediately applied his theory to the magnetism of the earth, and the these currents running in circles concentric to the axis of the magnet and in a genesis of electrodynamics may, indeed, have been as Ampère stated it. On the plane perpendicular to this axis. By implication, the earth also contained cur- other hand, there is an account of the meetings of the Académie des Sciences at rents which gave rise to its magnetism. Ampère’s theory was attacked by the great which Ampère spoke of his discoveries and presented a somewhat different order Swedish chemist Jöns Jacob Berzelius in a letter to his French colleague Claude of discovery. It would appear that Oersted’s discovery suggested to Ampere that Louis Berthollet, to which Ampère replied in a letter to François Arago. These two current-carrying wires might affect one another. It was this discovery that are the third and fourth items in this collection; the fifth and final part is the text he announced to the Académie on 25 September. Since the pattern of magnetic of a lecture to the Académie on 2 April 1821 in which Ampère again stressed the force around a current-carrying wire was circular, it was no great step for Ampère identity of electricity and magnetism. The bibliographical complexity of this work the geometer to visualize the resultant force if the wire were coiled into a helix. is a direct result of Ampère’s modus operandi: “His work was marked by flashes The mutual attraction and repulsion of two helices was also announced to the of insight, and it often happened that he would publish a paper in a journal one Académie on 25 September. What Ampère had done was to present a new theory week, only to find the next week that he had thought of several new ideas that he of magnetism as electricity in motion … felt ought to be incorporated into the paper. Since he could not change the orig- inal, he would add the revisions to the separately published reprints of the paper “Ampère’s first great memoir on electrodynamics was almost completely phenom- and even modify the revised versions later if he felt it necessary” (Norman). Only enological, in his sense of the term. In a series of classical and simple experiments, three other copies of this work listed by ABPC/RBH (all later issues). OCLC lists he provided the factual evidence for his contention that magnetism was electrici- only one copy of this issue of the collection (University College, London), and we ty in motion. He concluded his memoir with nine points that bear repetition here, found no record of any earlier issue. since they sum up his early work. Provenance: Société Philotechnique d’Ostende (inscribed in the hand of Ampère). 1. Two electric currents attract one another when they move parallel to one an- AMPÈRE, André-Marie. other in the same direction; they repel one another when they move parallel but in opposite directions. 2. It follows that when the metallic wires through which they pass can turn only in parallel planes, each of the two currents tends to swing the other into a position parallel to it and pointing in the same direction. 3. These attractions and repulsions are absolutely different from the attractions and repulsions of ordinary [static] electricity. 4. All the phenomena presented by the mutual action of an electric current and a magnet discovered by M. Oersted ... are covered by the law of attraction and of repulsion of two electric currents that has just been enunciated, if one admits that a magnet is only a collection of electric currents produced by the action of the particles of steel upon one another analogous to that of the elements of a voltaic pile, and which exist in planes perpendicular to the line which joins the two poles of the magnet. 5. When a magnet is in the position that it tends to take by the action of the terrestrial globe, these currents move in a sense opposite to the apparent mo- tion of the sun; when one places the magnet in the opposite position so that the poles directed toward the poles of the earth are the same [S to S and N to N, not south-seeking to S, etc.] the same currents are found in the same direction as the apparent motion of the sun. 6. The known observed effects of the action of two magnets on one another obey the same law. 7. The same is true of the force that the terrestrial globe exerts on a magnet, if one AMPÈRE, André-Marie. admits electric currents in planes perpendicular to the direction of the declina- “Once again Ampère’s extraordinary willingness to frame ad hoc hypotheses is tion needle, moving from east to west, above this direction. evident. Volta had suggested that the contact of two dissimilar metals would give rise to a current if the metals were connected by a fluid conductor. Ampère sim- 8. There is nothing more in one pole of a magnet than in the other; the sole dif- ply assumed that the contact of the molecules of iron in a bar magnet would ference between them is that one is to the left and the other is to the right of the give rise to a similar current. A magnet could, therefore, be viewed as a series of electric currents which give the magnetic properties to the steel. voltaic piles in which electrical currents moved concentrically around the axis of the magnet. Almost immediately, Ampère’s friend Augustin Fresnel, the creator 9. Although Volta has proven that the two electricities, positive and negative, of of the wave theory of light, pointed out that this hypothesis simply would not the two ends of the pile attract and repel one another according to the same laws do. Iron was not a very good conductor of the electrical fluids and there should, as the two electricities produced by means known before him, he has not by that therefore, be some heat generated if Ampère’s views were correct. Magnets are not demonstrated completely the identity of the fluids made manifest by the pile and noticeably hotter than their surroundings and Ampère, when faced with this fact, by friction; this identity was proven, as much as a physical truth can be proven, had to abandon his noumenal explanation.