‎"ELSTER, JULIUS & HANS GEITEL.- THE FINAL PROOF OF THE EXISTENCE OF ELECTRONS AS CONSTITUENTS OF MATTER.‎
‎Ueber die Electrisirung der Gase durch glühende Körper.‎

‎Leipzig, Johann Ambrosius Barth, 1887. Without wrappers as issued in ""Annalen der Physik und Chemie. Hrsg. von G. Wiedemann."", Neue Folge Bd. 31, 5. Heft. Pp. 1-144 a. 1 folded plate.(entire issue offered ""Heft"" 5). The Elster-Geitel-paper: pp. 109-126. Clean and fine.‎

Reference : 44845

‎First appearance of this notable ppaer in which a decisive experimental proof are given of the electron as a constituent of the atom.""In 1887 Elster and Geitel discovered the ""electrification of gases by means of incandescent bodies"", a finding that later was very significant in thermionics. Their finding of the emission of negative electricity from incandescent filaments was decisive in the proof that Thomson’s ""corpuscles"" (electrons) are a constituents of all matter.""(DSB).The issue contains another importent paper by BUNSEN ""Ueber das Dampfcalorimeter"", pp. 1-14, in which Bunsen describes his invention of the Vapor Calorimeter.‎