Cathode rays were first named by which German physicist?
Cathode ray:  They were first observed in 1869 by German physicist Johann Wilhelm Hittorf, and were named in 1876 by Eugen Goldstein "Kathodenstrahlen", or cathode rays. Eugen Goldstein: Eugen Goldstein (5 September 1850 – 25 December 1930) was a German physicist.
Eugen Goldstein