Possible existence of a neutron by H.C. Webster Lyrics

In a paper to appear shortly in the Proceedings of the Royal Society, I have reported observations on the absorption of the radiations produced in beryllium and other light elements by bombardment with polonium α-particles. The experiments indicated that the radiations emitted from beryllium, boron, and fluorine in the ‘forward’ direction, that is, in roughly the same directions as the α-particles producing them, were less absorbable than those emitted in the backward direction. In my paper I show that this observation is very difficult to reconcile with conservation of momentum and energy if the radiations are assumed to be γ-radiations corresponding to the energy available.

Now that Dr. Chadwick has put forward evidence for the existence of neutrons, this difficulty appears to be solved. Thus if the radiations are assumed to consist of neutrons, it follows immediately from the conservation laws that those emitted in the forward direction must have considerably more energy (50 per cent in the case of beryllium) than those emitted in the backward direction. This suggests that the radiations from boron and fluorine, as well as that from beryllium, consist at least in part of neutrons.