Goldstein, Eugen (1850-1930)  German physicist who investigated
electrical discharges through gases at low pressures. He
discovered canal rays and gave cathode rays their name.
Goldstein was born at Gleiwitz, Upper Silesia (now Gliwice,
Poland), and studied at Breslau and Berlin. He worked at the
Berlin Observatory 1878-90, and was eventually appointed head of
the Astrophysical Section of Potsdam Observatory. In 1876
Goldstein demonstrated that cathode rays can cast shadows and
that the rays are emitted perpendicular to the cathode surface.
He then showed how cathode rays could be deflected by magnetic
fields. In an experiment 1886, he perforated the anode and
observed glowing yellow streamers emanating from the
perforations. He termed them Kanalstrahlen or canal rays.
Goldstein later investigated the wavelengths of light emitted by
metals and oxides when canal rays impinge on them, and observed
that alkali metals show bright spectral lines. In his last
paper, published 1928, he observed that a trace of ammon