  Dawning neutron physics was more complex than one might expect. The chance
that the neutron comprised a proton and an electron was diffusely taken into
account after the discovery of the neutron. Moreover, uncertainties persisted
about the composition of beryllium radiation until it was realized that the
latter comprised both neutrons and gamma-rays. The interaction of neutrons with
matter and nuclei was soon investigated. Both a spatial symmetry, a symmetry of
charge, and a symmetry in the nuclear reactions soon emerged. The relation of
negative beta-decay to the neutron abundance in nuclei was moreover reviewed.
Positive beta-radioactivity induced by alpha-particles was eventually
announced, having been foreseen some weeks before. Accelerated deutons and
protons shortly afterwards revealed to be efficient in inducing radioactivity.
The physics institute in Rome got ready to start research on neutrons, but
apparently it only planned to go through alpha-induced radioactivity, at first.
If so, it is then plausible that some new results achieved by foreign
laboratories eventually bent Fermi to neutrons. Fermi's discovery of
neutron-induced radioactivity is reviewed with regard to investigations then
current, once more showing simplicity as a distinctive trait of Fermi's way of
doing physics.
