Referee's rpeort by Patrick Maynard Stuart Blackett, on a paper 'Concerning the scattering of fast electrons and of cosmic-ray particles' by Evan James Williams Sectional committee: Physics Recommended for publication in Proceedings. The name 'yubon' that has been selected for the new heavy particle should be changed to 'mesotion', as this term has already been used by Niels Bohr and Milliken. It is long, but can't be shortened without detriment. It could be divided into two instead. An extensive summary is need for a paper of this type. He cannot judge the validity of the theoretical agreements. [Published in Proceedings of the Royal Society A, 1939]. Endorsed on verso as received 11 November 1938. November 1938