Neutral Weak Interaction Currents

The consequences of postulating that the strangeness-conserving weak interactions are symmetric in isotopic spin space (i.e., the leptons paired in isotopic spin doublets) are traced, with special attention to the resultant neutral weak currents and possible experiments to detect such currents. Far from being excluded experimentally, this theory in fact leads generally to only very difficult-to-detect effects such as elastic neutrino-nucleon scattering (order $G$ in amplitude). Circular dichroism (microwave frequencies) of first excited hydrogen is expected. Other possible experimental subjects are also discussed.