Francis E. Nipher (1847 – 1926? *). “On the Nature of the Electric Discharge. The One-Fluid and the Two-Fluid Theories.” Transactions of the Academy of Science of St. Louis 19:1 (February 18, 1910)
UC Southern Regional Library Facility, digitized 5 February 2014
Republished in 1914 — but with a different selection of images — as Experimental Studies in Electricity and Magnetism
…revealed by the presence of small black points here and there towards which fine discharge lines proceed, and from which the discharge passed to the wire below. The form of these lines seems to have been somewhat affected by electro-magnetic induction from the discharge wire across the upper film. The fogging effect on a film from which electricity passes to a conductor, is much less than that caused by a like discharge of electicity against the film.A stunning series of photographs illustrate this paper.
Had been searching for “sycamore.”