A systematic method to test the C s t and Т аЪ invariances of the electromagnetic interaction is to use the inelastic scattering P+N -• P+T where № is the charged lepton, N is the target nucleus (or nucleon), and Г 5*N but, otherwise, can be any system of the strongly interacting particles. General expressions for the various possible C s t-and r sr noninvariant effects in such reactions are derived and discussed. Similar con siderations are also applied to the decay A -> B+e + -{-e~", where A and В are any complexes of the strongly interacting particles.