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 ammonia was present after the discharge in a tube containing nitrogen and hydrogen. Much later investigations were begun to see if biologically important molecules, and hence life, could have originated in this way.