The Origins of the Green Glow

A green glow was visible at the opposite end of a tube to where electrodes are placed. When an electric field as opposed to a magnetic field was applied across the tube it demonstrated that whatever was causing it had to be negatively charged. Thompson determined that cathode rays must have a much smaller mass than the hydrogen atom about 2000 times smaller and if these new particles had a mass of only one two thousandth of a hydrogen atom that meant that the atom had probably been split. In this model these negatively charged electrons were spread throughout some positively charged material which formed the the rest of the atom.