HALLWACHS, WILHELM. - THE "HALLWACHS EFFECT"

Ueber den Einfluss des Lichtes auf electrostatisch geladene Körper.

Leipzig, Johann Ambrosius Barth, 1888. Without wrappers as issued in "Annalen der Physik und Chemie. Hrsg. von G. Wiedemann.", Neue Folge Bd. 33, 2. Heft (= No 2). Titlepage to vol. 33. Smal stamps to verso of title and titlepage. Pp. 241-416 a. 1 plate (entire issue offered "Heft" 2). Hallwach's paper: pp. 301-312. Clean and fine.

First appearance of this pioneer paper in the history of the PHOTOELECTRIC EFFECT, as Hallwachs here for the first time showed that metals lose their negative charges under the action of ultraviolet radiation and becomes positive charged. The earliest speculations of the nature of the effect predates the discovery of the electron in 1897 by J.J. Thomson.

"This process, which is called the photoelectric effect or Hallwachs effect, forms the basis for the physics of the photoelectric cell and was theoretically interpreted by Einstein in 1905 in Einstein's work on light quanta."(DSB VI, p.74).

"On the basis of his heuristic principle, Einstein proposed the following 'simplest picture' for the photoeffect. A light-quantum gives all its energy to a single electron, and the energy transfer by one light-quantum is independent of the presence of other light-quanta....and he gave several other applications of his heuristic principle..."(Pais in "Subtle is the Lord" pp. 380-81).
Magie "A Source Book in Physics", pp. 578 ff.

Order-nr.: 43537