THE FIRST SCATTERING EXPERIMENT

LENARD, P. (PHILIPP).

Über die Absorption von Kathodenstrahlen verschiedener Geschwindigkeit.

Leipzig, Ambrosius Barth, 1903. 8vo. In full black cloth with gilt lettering to spine. In "Annalen der Physik", Vierte Folge, Band 12. Entire volume offered. Library labels to front end papers and stamp to title page, otherwise fine and clean. Pp. 714-44. [Entire volume: VIII, 1184 pp. + 3 plates.].

First appearance of Lenard's important paper in which he for the first time documented that cathode rays can traverse atoms themselves thus creating the very first scattering experiment.

"In 1903 Lenard studied in detail the absorption of cathode rays, i.e., electrons, by different materials. He found that they can traverse quite thick layers of solid matter and concluded that the cathode rays must be able to traverse the atoms themselves. He therefore assumed that the atoms are composed of 'finer constituents' which he called dynamides, ' with many free spaces between them' such that the cathode rays could pass through these free spaces. Lenard was the first to probe the structure of the atom by shooting particles at it. Such scattering experiments with atoms or its constituents as targets are done to this day." (The Harvest of a Century).

"Lenard was in fact able to infer from the absorption of the cathode rays by matter the correct conclusion that the effective center of the atom is concentrated in a tiny fraction of the atomic volume previously accepted in the kinetic theory of gases. Lenard’s "dynamide" was an important predecessor of the atomic model of Rutherford, who in 1910-1911, on the basis of the deflections of a particles, drew the same conclusion as Lenard had earlier from the scattering of electrons." (DSB).

Order-nr.: 50370