Johann Wilhelm Hittorf
Hittorf, Johann Wilhelm
Born Mar. 27, 1824, in Bonn; died Nov. 28, 1914, in Münster. German chemist and physicist. Professor at the Münster Academy from 1852 to 1889.
In 1853-59, Hittorf established that in the electrolysis of solutions, positive and negative ions are not transported at the same rate; he called the fraction of the total amount of electricity carried by each kind of ion the transport numbers. He developed a method of determining them and measured the transport numbers of many ions. Hittorf investigated the spectra of incandescent gases (1864) and the passage of electricity through highly rarefied gases (1869-83) and observed (1869) and described the properties of cathode rays, thus initiating the study of them.