Du Rapport entre le pouvoir émissif et le pouvoir absorbant des Corps pou la Chaleur et la Lumière. Traduit de l'allemand par Georges Leclanche.

Paris, Victor Masson et Fils, 1861. Without wrappers. In: "Annales de Chimie et de Physique", 3e Series - Tome 62, Cahier Juin 1861. Titlepage to vol. 62. Pp. 129-256. (The entire issue offered). Kirchhoff's paper: pp. 160-192. Small stamps to verso oftitlepage.

First French edition of a milestone paper by "The Grandfather of Quantum Theory" in which he formulates the law named after him, "KIRCHHOFF'S LAW", which was the "key to the whole thermodynamics of radiation. In the hands of Planck, Kirchhoff's successor to the Berlin chair, it proved to be the key to the new world of the quanta, well beyond Kirchhoff's conceptual horizon."(DSB, VII, p.382).

"Kirchhoff's Law of Thermal Emission was formulated in 1859 (Über das Verhältnis....) - the paper offered here in the first French version. It is at the same time the simplest and least understood law in physics. Kirchhoff's law states that given thermal equilibrium with an enclosure, the radiation inside will be always black, or normal, in a manner which is independent of the nature of the walls, or the objects they contain. This is known as the concept of universality. That is, that radiation within an enclosure can always be described by a universal function dependent only ontemperature and frequency. This universal function was first given us by Max Planck, in 1900. Kirchhoff's law STANDS AT THE HEARTH OF ALL MODERN ASTROPHYSICS. It is the basis for setting the temperature of the stars, for the gaseous model of the Sun, and for believing that we now know the temperature of the entire universe."(Pierre-Marie Robitaille)..

The research background for the paper was his unexpected observation that if the intensity of the solar spectrum increased above a certain limit, the dark D lines were made much darker by the interposition of the sodium flame. he instantly felt, that he had got hold of "something fundamental".

Another notable, and importent paper in the development of photography, is in the same issue ALPHONSE POITEVIN "De l'Action chimique de la Lumiere sur les Substances organiques. Son emploi à l'impression photographique."Pp. 192-210.

Order-nr.: 44131

DKK 5.500,00