for the hydrogen ion in solutions. Also since the approximate equality of

in gases and solutions meant that

was at least of the same order in both, the only possible conclusion was that the negative ion which appears in discharges in exhausted tubes has a mass, i.e., an inertia, only one-thousandth of the mass of the lightest-known atom, namely, the atom of hydrogen. Later more accurate experiments have fixed the correct value of

for cathode rays at

.

Furthermore, J. J. Thomson and after him other experimenters showed that