ABSTRACT
The phenomenon of Zeeman effect explores that when the light was viewed in a direction parallel to the magnetic lines, only the two outer lines were visible, these being circularly polarised in opposite directions to each other. The process of ionisation by collisions between ions and molecules of a gas is examined by investigating the currents between parallel-plate electrodes when ultra-violet light falls on the negative electrode or when the gas is ionised by Röntgen rays. If the gas is at a high pressure, the current increases with the electric force and attain a maximum value, which is not exceeded unless very large forces are used. Mohler and Shelby Foote, in experimenting with phosphorus, iodine, sulphur, nitrogen, oxygen and hydrogen found, except in the case of hydrogen, that these elements exhibit resonance and ionisation potentials similar in relative magnitudes to those obtained with metallic vapours.
