Goldstein, Eugene

The next major discoveries occurred almost a century later (1879-1897). Although Dalton pictured atoms as indivisible, various experiments, particularly those of William Crookes and Eugene Goldstein, indicated that the atom is composed of charged (+ and —) particles. 

The study of the so-called canal rays by the German physicist Eugen Goldstein, observed in a special cathode-ray tube with a perforated cathode, let to the recognition in 1902 that these rays were positively charged particles (protons). Finally, years later in 1932 the British physicist James Chadwick discovered another particle in the nucleus that had no charge, and for this reason was named neutron. 

At the time, however, physicists did not know what an electric current might be and they could not easUy tell just what it was that was moving from the cathode to the anode. Whatever it was, it traveled in straight lines (for it cast sharp shadows), so without committing oneself to any decision as to its nature, one could refer to it as a radiation. Indeed, in 1876, the German physicist Eugen Goldstein (1850-1930) named the flow cathode rays. 

German physicist Eugen Goldstein discovers cathode rays. 

Hedenus, M., Eugen Goldstein and his laboratory work at Berlin Observatory , Astronomische Nachrichten 2002,323, 567—569. 

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