Neutral currents, unified fields and a new property of elementary particles:- charm

Recent experimental work at CERN and SLAC on neutrino interactions is discussed and shown to support the validity of the nuclear quark model and to prove the existence of neutral weak current. The results are interpreted in terms of the unified weak and e.m. interaction theory. The fact that neutral currents have so far not been observed can be explained with the aid of a fourth quark which possesses the property of 'charm'. The discovery of the psi degrees particle allows the inference to be made about other charmed particles.