Referee's report by William Barlow, on a paper 'Optical investigation of crystallised nitrogen, argon, methane, and some of the simpler organic compounds, of low melting points' by Walter Wahl Sectional Committee: Physics and Chemistry Recommended for publication in the 'Proceedings of the Royal Society of London'. Finds the conclusions interesting. In attached letter, apologises for lateness of response, due to being detained overseas by his wife's illness. [Published in the 'Proceedings of the Royal Society of London', 1912] Endorsed on recto as received 8 July 1912. 5 July 1912