Mémoires sur l'action mutuelle de deux courants électriques, sur celle qui existe entre un courant électrique et un aimant ou le globe terrestre, et celle de deux aimants [aimans] l'un sur l'autre

First edition printed in small numbers of this offprint from the Annales de chimie et de physique.

Illustrated with 5 folding plates at rear. As issued in its rare original beige paper covers with some tears to the corners and spine.

An extremely rare copy of Ampère's first dissertation on electrodynamics, presenting his first reflections on the equivalence between magnets and cur­rents.

Ampère was immediately captivated by the Danish scientist Ørsted's demon­stration of the effects of electricity flowing through wires on a magnetized needle — an experiment that Arago re­ported to the Académie des sciences on 4 September 1820. In a prodigious effort, Ampère created electrodynamics and demonstrated his discoveries to the Académie in the span of seven consec­utive weeks. This copy is the off print first edition of his very first scientific papers on the subject, during sessions at the Académie that remain seminal in science history. The publication of his study also coincided with the birth of his very famous "bonhomme d'Ampère" introduced in his experimental notes.
In these Memoirs, starting from a dis­tinction between voltage electricity (static electricity; magnetism) and cur­rent electricity, Ampère lays down a coherent theory suggesting that magne­tism is merely a special manifestation of electricity.
The illustrations at the end record the devices invented and built by Ampère himself for his decisive experiments:
The astatic compass (pl. 4) prototype of the galvanometer, eliminating the influ­ence of Earth's magnetic field on a mo­bile system and facilitating the study of magnetic fields generated by a current.
The solenoid prototype (pl. 5), two con­ductive wires wound in spirals replac­ing magnets, attracting or repelling each other when a current flows through them, depending on the direction of the current. To achieve this experiment—ini­tially attempted with batteries that were too weak — Ampère had to purchase the large battery intended for physics courses at the Faculty of Sciences.
The "solenoid" (pl. 2), a term he invent­ed for helical winding which replaced the spiral of the previous apparatus. This winding is now used in a large number of devices, including transform­ers and electromagnets.
The instrument used for his fundamen­tal experiment conducted before the Academy, which verified the law stating that two parallel currents in the same direction attract each other whereas two currents in opposite directions re­pel (pl. 1).

A rare milestone in the history of sci­ence, paving the way for revolutionary inventions such as the first electric motor and the electromagnet.