Second referee's report by Nevill Francis Mott, on two papers 'Some properties of the metallic state I—Metallic hydrogen and its alloys' and 'Some properties of the metallic state II—Metallic hydrogen and deuterium' by Alfred Rene Jean Paul Ubbelohde Sectional Committee: Physics Recommended for publication in the 'Proceedings of the Royal Society of London', as revised. [Published in the 'Proceedings of the Royal Society of London'] Endorsed on verso as received 2 January 1937. [January 1937]