FRESNEL, AUGUSTIN. - FORMULATING FRESNEL'S "SINE-LAW AND" FRESNEL'S "TANGENT LAW" GERMAN EDITION.

Betrachtungen über die Polarisation des Lichts. (+) Ueber die Gesetzt der Modificationen, welche die Reflexion dem polarisirten Lichte einprägt. (2 Papers).

(Leipzig, Johann Ambrosius Barth, 1831). Without wrappers as issued in "Annalen der Physik und Chemie. Hrsg. von J.C. Poggendorff", Bd. 22 (98) Fünftes Stück. Pp. 1-160. (The entire issue offered). Fresnel's papers: pp. 68-89 and pp. 90-125. Clean and fine.

First appearance in German of two importent memoirs on polarized light, refraction and reflexion of light.

The first paper unites two of his earlier papers on polarization as an introduction to the second paper. Having mastered the wave theory, Fresnel tackled the phenomena of polarization and of double refraction, and he obtained results which amazed the scientific world. These results survived the criticism of his contemporaries and of his succcessors, and are still accepted today.

The second paper offered contains the first German edition of the importent paper in which Fresnel formulates a theory of reflection and refraction referring them to the dynamical properties of the luminiferous media and stating the two laws that bears his name, the "Sine-law" and the "Tangent-law".

This memoir was for some time considered lost, it was presented to the Academy in 1823, but found later in the papers of Fourier. "Diese Abhandlung ist bereits am 7. Jan. 1823 in der Pariser Academie vorgelesen, nach der Zeit aber abhanden gekommen, und erst kürzlich unter den Papieren des verwigten Fourier wieder aufgefunden"(Editors footnote).

In the memoir "He adopts Young's principle, that reflection and refraction are due to differences in the inertia of the aether in different material bodies, and supposes (as in the memoir on aberration) that the inertia is proportional to the inverse square of the velocity of propagation of light in the medium. The conditions which he proposes to satisfy at the interface between two media are that the displacements of the aadjacent molecules, resolved parallell to this interface, shall be equal in the two media; and that the energy of the reflwected and refracted waves together shall be equal to that of the incident wave."(Whittaker "A History of the Theories of Aether and Electricity" I, p.123).

Order-nr.: 44089