
As quoted by Walter Kaufmann, "The Development of the Electron Idea" (Nov. 8, 1901) The Electrician Vol. 48 https://books.google.com/books?id=owxRAAAAYAAJ pp. 95-97. Lecture delivered before the 73rd Naturforscher Versammlung at Hamburg. From the Physikalische Zeitshrift, of October 1, 1901.