In this third experiment, Thomson used the same apparatus as in the second experiment, but placed the discharge tube between the poles of a large electromagnet. He found that the mass-to-charge ratio for cathode rays was more than a thousand times lower than that of a hydrogen ion (H+). The results suggested that either the particles were very light, or they carried a huge charge compared to an ion. Thomson decided that the particles were more than a thousand times smaller than a hydrogen ion. He then came up with the idea that the particles in cathode rays were of particles that came from within atoms.