Testing time reversal symmetry using molecules

Some years ago while on sabbatical leave in Oxford I discussed with George Series the experiments in my group to measure the electric dipole moments of the proton and electron using the magnetic resonance in molecules. He asked about the current interest in this kind of measurement and he wanted to find out why we use molecules rather than something simple like the hydrogen atom. After about an hour, George was satisfied with the answers I gave him, but on several occasions after that, he encouraged me to write up some notes about all this. Well George, here they are.